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  Free Full Text References 17 Dec 2007


Free Full Text ArticleEffects of as-cast and wrought Cobalt-Chrome-Molybdenum and Titanium-Aluminiu...
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Effects of as-cast and wrought Cobalt-Chrome-Molybdenum and Titanium-Aluminium-Vanadium alloys on cytokine gene expression and protein secretion in J774A.1 macrophages.

Eur Cell Mater. 2007;14:45-54; discussion 54-5

Authors: Jakobsen SS, Larsen A, Stoltenberg M, Bruun JM, Soballe K

Insertion of metal implants is associated with a possible change in the delicate balance between pro- and anti-inflammatory proteins, probably leading to an unfavourable predominantly pro-inflammatory milieu. The most likely cause is an inappropriate activation of macrophages in close relation to the metal implant and wear-products. The aim of the present study was to compare surfaces of as-cast and wrought Cobalt-Chrome-Molybdenum (CoCrMo) alloys and Titanium-Aluminium-Vanadium (TiAlV) alloy when incubated with mouse macrophage J774A.1 cell cultures. Changes in pro- and anti-inflammatory cytokines (TNF-alpha, IL-6, IL-alpha, IL-1beta, IL-10) and proteins known to induce proliferation (M-CSF), chemotaxis (MCP-1) and osteogenesis (TGF-beta, OPG) were determined by ELISA and Real Time reverse transcriptase - PCR (Real Time rt-PCR). Lactate dehydrogenase (LDH) was measured in the medium to asses the cell viability. Surface properties of the discs were characterised with a profilometer and with energy dispersive X-ray spectroscopy. We here report, for the first time, that the prosthetic material surface (non-phagocytable) of as-cast high carbon CoCrMo reduces the pro-inflammatory cytokine IL-6 transcription, the chemokine MCP-1 secretion, and M-CSF secretion by 77%, 36%, and 62%, respectively. Furthermore, we found that reducing surface roughness did not affect this reduction. The results suggest that as-cast CoCrMo alloy is more inert than wrought CoCrMo and wrought TiAlV alloys and could prove to be a superior implant material generating less inflammation which might result in less osteolysis.

PMID: 17849370 [PubMed - indexed for MEDLINE]


Free Full Text ArticleEvaluation of the apical seal after intraradicular retainer removal with ultr...
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Evaluation of the apical seal after intraradicular retainer removal with ultrasound or carbide bur.

Braz Oral Res. 2007 Jul-Sep;21(3):253-8

Authors: Campos TN, Inoue CH, Yamamoto E, Araki AT, Adachi LK, Rodriguez JE

There are situations in which intraradicular retainers have to be removed and replaced. The objective of this research was to evaluate the apical seal after the removal of a custom cast post and core with a carbide bur or with an ultrasound apparatus. Twenty five roots of extracted human incisors were used. They were endodontically treated and prepared to receive the posts. The posts and cores were cast with 2 types of dental alloys, CuAlZn and PdAg, and were cemented with zinc phosphate cement. After 24 hours, they were removed using the two above mentioned techniques. Then, the roots had their external surface made impermeable by two layers of cyanoacrylate adhesive, leaving only the cervical area for dye penetration. The teeth were immersed in rhodamine for 24 hours. They were then cut and observed under an optical microscope and analyzed with appropriate software (Imagelab). The results were submitted to ANOVA, and they evidenced that, regarding the alloy factor, PdAg posts presented a larger mean infiltration value (2.23 +/- 0.48 mm) as compared to the posts made of CuAlZn (1.39 +/- 0.48 mm) (p = 0.025). Regarding the technique factor, there was no significant difference (p = 0.9) between the removal of the intraradicular retainer using ultrasound (1.99 +/- 0.62 mm) or using a rotating cutting instrument (1.62 +/- 0.62 mm). Under these experimental conditions, it was possible to conclude that the degree of apical leakage was directly related to the alloy type, and it was present in both techniques used.

PMID: 17710292 [PubMed - in process]


Free Full Text ArticleMulti-link Vision and MiniVision stent registry in Asian patients with corona...
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Multi-link Vision and MiniVision stent registry in Asian patients with coronary artery disease: a prospective, multi-center study.

Chin Med J (Engl). 2007 Jun 20;120(12):1093-6

Authors: Xu YW, Wei YD, Tang K, Chen YQ, Li WM, Yu XJ, Qin YW, Qi GX, Qu P, Hou YQ, Jain A, Grant P, Ramesh G, Ramesh B, Piamsomboon C, Kuanprasert S, Gwon HC, Cho YH, Kamar HH, Huang CX

BACKGROUND: Recent studies have showed that the fine mesh stents are associated with a significant reduction in both clinical and angiographic re-stenosis of the coronary arteries. To maintain a very satisfactory radio-opacity using the stents, Guidant of the USA has designed a new type of bare metal stents (BMS)-Multi-link (ML) Vision/ML MiniVision stents. The clinical outcomes of Asian patients with coronary artery disease (CAD) after implanting the Multi-link Vision or MiniVision stent were investigated in this study. METHODS: An observational, prospective, multi-center, non-randomized post marketing registry was conducted to demonstrate the efficacy of the BMS-ML Vision/ML MiniVision stents. The primary end point of the registry was clinical target lesion revascularization (TLR) at a 6-month follow-up. The major secondary end points included the rate of major adverse cardiac events (MACE) and serious adverse events (SAE) in hospital and at 6 months; and the rate of clinical TLR as a function of the type of angina. A total of 429 Asian people with 449 lesions from 14 centers were selected for this study. The average reference diameter of the lesions was (3.0 +/- 0.5) mm, and the mean length was (15.7 +/- 5.0) mm. RESULTS: The successful rate of the procedure was 99.3%. Twenty-five percent of the lesions were treated by direct stenting without pre-dilation. Eighty-six percent of the lesions were implanted with ML Vision stent. After the 6-month follow-up, the rate of clinical TLR was 1.4%. The MACE, SAE and target vessel revascularization (TVR) were 6.8%, 3.5% and 1.4% respectively. CONCLUSION: The current registry showed the excellent 6-month clinical outcomes of ML Vision/ML MiniVision stents in Asian patients with CAD.

PMID: 17637228 [PubMed - indexed for MEDLINE]


Free Full Text Article[Dental health, mercury and health injuries]
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[Dental health, mercury and health injuries]

Tidsskr Nor Laegeforen. 2007 Jun 14;127(12):1671

Authors: Aas O, Hilt B

PMID: 17571114 [PubMed - indexed for MEDLINE]


Free Full Text Article[Health complaints related to dental filling materials]
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[Health complaints related to dental filling materials]

Tidsskr Nor Laegeforen. 2007 May 31;127(11):1524-8

Authors: Lygre GB, Helland V, Gjerdet NR, Björkman L

BACKGROUND: A wide range of materials is used in dental treatment. To what extent these materials lead to adverse reactions is under dispute. The aim of this study was to investigate whether patients with suspected adverse reactions to dental materials experienced an improvement in health after these materials were replaced. MATERIAL AND METHODS: Information on health complaints related to dental materials was obtained from the Dental Biomaterials Adverse Reaction Unit in Bergen, Norway for 142 patients. A follow-up questionnaire regarding subjective health was sent to these patients 1(1/2) to 2(1/2) years later. A similar questionnaire was sent to a reference group of 800 persons drawn from the general population. RESULTS: The patient group had more health complaints than the reference group (p < 0.001) at baseline. Of the 84 patients who completed the questionnaire (59%) 35 had changed dental materials. Amalgam fillings had been replaced in most of these patients. 23 patients (66%) reported improved health after replacement. Intraoral complaints decreased significantly (p = 0.022), and were most pronounced in patients with lesions in contact with dental materials. The intensity of various health complaints decreased slightly in most patients with replaced dental materials, but the patient group still had significantly higher health complaint indices than the reference group. INTERPRETATION: The intensity of subjective health complaints was reduced after replacement of dental materials, but it was still higher than for a comparable group in the general population. The results indicate that there may be a specific health effect of replacing dental materials, but normal symptom fluctuations over time and placebo effects such as positive effects from expectations and general care from the health personnel may have had an influence.

PMID: 17551559 [PubMed - indexed for MEDLINE]


Free Full Text ArticleRestoring function and esthetics in a patient with amelogenesis imperfecta: a...
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Restoring function and esthetics in a patient with amelogenesis imperfecta: a case report.

J Contemp Dent Pract. 2007;8(4):95-101

Authors: Gokce K, Canpolat C, Ozel E

AIM: The purpose of this case report is to present the esthetic and functional rehabilitation of the teeth in a 22-year-old patient with Amelogenesis imperfecta (AI). BACKGROUND: AI is a group of hereditary defects of enamel, unassociated with any other generalized defects. It is a rare developmental abnormality of the enamel, with a variable occurrence of approximately 1:4000 to 1:14000 in Western populations. Al results in poor development or complete absence of the enamel of the teeth caused by improper differentiation of the ameloblasts. REPORT: This report describes the diagnosis and treatment of a young male patient with AI and missing molar teeth using contemporary restorative strategies. Initially, the tooth surfaces were treated with a professional cleaning along with conservative restorative treatment. Later, metal-ceramic crowns for posterior teeth and full-ceramic crowns for anterior teeth were utilized for final restorations. SUMMARY: The complexity of the management of patients with AI supports the suggestion the dental profession should have appropriate methods for the rehabilitation of rare dental disorders. The treatment of patients with AI should start with early diagnosis and intervention to prevent later restorative problems.

PMID: 17486193 [PubMed - indexed for MEDLINE]


Free Full Text ArticleAnalysis of the diametral compressive bond strength between composite resin a...
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Analysis of the diametral compressive bond strength between composite resin and amalgam in different stages of oxidation.

Minerva Stomatol. 2007 Apr;56(4):209-13

Authors: Benitez Catirse AB, Oliveira Pagnano V, Da Silva Mello AS, Do Nascimento C, Mardegan Issa JP

AIM: Amalcomp is a technique that combines composite resin to amalgam in restorative procedures to improve esthetics and minimize the negative effects of polymerization on dental tissues. The objective of this in vitro study was to measure the diametral compressive bond strength between Fill Magic composite (Vigodent) versus Permite (DFL) or Velvalloy (SS White) amalgams in different oxidation stages. METHODS: Twenty-four cylinders of each amalgam brand were fabricated using a Teflon matrix and divided into 3 groups according to the immersion period in artificial saliva for oxidation: A (1 day), B (7 days) and C (30 days). After immersion, the amalgam cylinders were bonded to the composite specimens using the Scotch Bond Multi Use Plus (3M) bonding system. Diametral compression assays were then carried out in an EMIC-MEM 2000 universal testing machine set to 0.5 mm/min. Statistical analysis was performed using ANOVA and Tukey's test. RESULTS: The mean recorded strength (MPa) for each oxidation group was: A=9.71, B=8.21 and C=6.98 (A>B = C; P<0.01). Permite (7.24) provided significantly less adhesion to the composite than Velvalloy (9.36; P<0.05). There was no interaction between the factors alloy, resin and time. CONCLUSIONS: Under the conditions of this study, the less oxidized amalgam showed the greatest diametral compressive strength values.

PMID: 17452958 [PubMed - indexed for MEDLINE]


Free Full Text ArticleDental amalgam restorations and children's neuropsychological function: the N...
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Dental amalgam restorations and children's neuropsychological function: the New England Children's Amalgam Trial.

Environ Health Perspect. 2007 Mar;115(3):440-6

Authors: Bellinger DC, Daniel D, Trachtenberg F, Tavares M, McKinlay S

BACKGROUND: A concern persists that children's exposure to mercury vapor from dental amalgams produces neurotoxicity. OBJECTIVE: Our goal was to compare the neuropsychological function of children, without prior exposure to dental amalgam, whose caries were repaired using either dental amalgam or mercury-free composite materials. METHODS: We conducted a randomized controlled trial involving 534 6- to 10-year-old urban and rural children who were assessed yearly for 5 years using a battery of tests of intelligence, achievement, language, memory, learning, visual-spatial skills, verbal fluency, fine motor function, problem solving, attention, and executive function. RESULTS: Although the mean urinary mercury concentration was greater among children in the amalgam group than the composite group (0.9 vs. 0.6 microg/g creatinine), few significant differences were found between the test scores of children in the two groups. The differences found were inconsistent in direction. Analyses using two cumulative exposure indices--surface years of amalgam and urinary mercury concentration--produced similar results. CONCLUSIONS: Exposure to elemental mercury in amalgam at the levels experienced by the children who participated in the trial did not result in significant effects on neuropsychological function within the 5-year follow-up period.

PMID: 17431496 [PubMed - indexed for MEDLINE]


Free Full Text ArticleHistological comparison of bone to implant contact in two types of dental imp...
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Histological comparison of bone to implant contact in two types of dental implant surfaces: a single case study.

J Contemp Dent Pract. 2007;8(3):29-36

Authors: Shibli JA, Feres M, de Figueiredo LC, Iezzi G, Piattelli A

AIM: The purpose of this single case study was to evaluate the influence of different implant surfaces on human bone and osseointegration. METHODS AND MATERIALS: A 47-year-old partially edentulous woman received two experimental implants along with conventional implant therapy. Experimental implants placed in the mandibular ramus consisted of machined and anodized surfaces, respectively. After three months of healing, the experimental implants were removed and prepared for ground sectioning and histological analysis. RESULTS: The data demonstrate anodized implant surfaces present a higher percentage of osseointegration when compared to a machined surface in cortical human bone after a healing period of three months. CONCLUSION: This single case study suggests an anodized implant surface results in a higher percentage of bone to implant contact when compared to machined surfaced implants when placed in dense bone tissue. However, further investigations should be conducted.

PMID: 17351679 [PubMed - indexed for MEDLINE]


Free Full Text ArticleThe influence of commercially pure titanium and titanium-aluminum-vanadium al...
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The influence of commercially pure titanium and titanium-aluminum-vanadium alloy on the final shade of low-fusing porcelain.

J Contemp Dent Pract. 2007;8(2):97-104

Authors: Al Wazzan KA, Al Hussaini IS

AIMS: The aims of this study were to investigate the influence of commercially pure titanium (PTi) and titanium-aluminum-vanadium (Ti-6Al-4V) alloys (TiA) on the final shade of low-fusing porcelain bonded to them and to compare the shade changes with those of three conventional metal-ceramic systems. METHODS AND MATERIALS: A titanium casting unit was used to cast PTi and Ti-6Al-4V alloy specimens followed by A3 shade low-fusing porcelain (Noritake) being bonded to them. Gold-based (AuA), palladium-based (PdA), and nickel-chromium (Ni-Cr) alloys were cast with an automatic centrifugal casting machine, then A3 shade conventional porcelain material (Vita, VMK 95) was applied to them. Ten specimens of each metal were then fabricated. The CIE L* a* b* color coordinates of the specimens were measured with a spectrophotometer. RESULTS: All alloys had significant color changes when compared with A3 shade tabs. The color differences from the shade tabs were 5.79 for the Ti-6Al-4V group, 6.46 for PdA alloy, 8.12 for AuA alloy, 8.15 for Ni-Cr alloy, and 12.58 for PTi. The specimens differed from the shade tabs primarily because of the differences in a* and b* coordinate values. CONCLUSIONS: Predictable shade reproduction of metal-ceramic restorations (MCRs) may be impaired by the underlying metal. The PTi had the greatest color differences among all the tested metal when compared with the shade tabs, whereas the Ti-6Al-4V alloy had the lowest. PTi is more likely to affect the final shade of low-fusing porcelain than Ti-6Al-4V alloy.

PMID: 17277832 [PubMed - indexed for MEDLINE]


Free Full Text ArticleSilane based concepts on bonding resin composite to metals.
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Silane based concepts on bonding resin composite to metals.

J Contemp Dent Pract. 2007;8(2):1-8

Authors: Matinlinna JP, Vallittu PK

INTRODUCTION: The longevity of silane promoted adhesion of surface conditioned metallic materials is of concern in dentistry and poses both a functional and esthetic dilemma for the patient and dental professionals. Several methods for surface conditioning exist, but some are employed more frequently in clinical practice. AIM OF THE REVIEW: This overview aims to characterize and discuss the most commonly used surface conditioning methods based on silanization. The primary chemical features in silane treatment will also be presented. METHOD OF REVIEW: The literature regarding silane utilization was systematically selected and 68 cited references published during 1967-2005 were reviewed. Technical descriptions of different silica-coating (silicatization) methods are presented and some comparative clinical and in vitro experiences are reported. Some other surface condition methods applied in dental laboratories were also selected for presentation. CONCLUSION: It is concluded in this overview tribochemical silica-coating followed by a mandatory silane coupling agent application is a clinically proved, relevant adhesion promotion method to enhance the bonding of resin composites to metallic dental materials.

PMID: 17277821 [PubMed - indexed for MEDLINE]


Free Full Text ArticleEx vivo analysis of the debris remaining in flattened root canals of vital an...
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Ex vivo analysis of the debris remaining in flattened root canals of vital and nonvital teeth after biomechanical preparation with Ni-Ti rotary instruments.

Braz Dent J. 2006;17(3):233-6

Authors: Sasaki EW, Versiani MA, Perez DE, Sousa-Neto MD, Silva-Sousa YT, Silva RG

The purpose of this study was to assess the presence of apical debris remaining in the apical third of flattened root canals of vital and nonvital teeth after biomechanical preparation with Ni-Ti rotary instruments. Fresh-extracted human mandibular incisors were used in this study. The teeth had clinical indication for extraction and were submitted to cold pulp vitality testing and radiographic examination. Eighteen teeth were selected and randomly assigned to two groups (n=9), according to the clinical diagnosis, i.e., pulp vitality or pulp necrosis. The canals were instrumented with the ProTaper NiTi rotary system in the following sequence: S1--up to the middle third; SX--at the cervical third; S2--up to the apical third; and S1, F1, F2, F3--at the working length. The canals were irrigated with 1% sodium hypochlorite, dried and were submitted to the histological processing. Sections from the apical third were analyzed by an optical microscope (X40) that was coupled to a computer where the images were captured and analyzed using specific softwares. A grid was placed over these images to assess the total canal area and the areas with debris. Mann-Whitney U-test showed no statistically significant difference (p>0.05) between the teeth with pulp vitality (6.49 +/- 3.39) and those with pulp necrosis (5.95 +/- 2.22). It may be concluded that the clinical condition of pulp tissue did not interfere with the amount of debris remaining in the apical third of flattened root canals prepared with Ni-Ti rotary instruments.

PMID: 17262131 [PubMed - indexed for MEDLINE]


Free Full Text ArticleEvaluation of surface characteristics of Ti-6Al-4V and Tilite alloys used for...
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Evaluation of surface characteristics of Ti-6Al-4V and Tilite alloys used for implant abutments.

Braz Oral Res. 2006 Oct-Dec;20(4):307-11

Authors: Lima EM, Silva WJ, Moura JS, Faot F, Del Bel Cury AA

The aim of this study was to evaluate surface free energy (SFE), surface roughness (SR) and surface hardness (SH) of two commercially available materials for fabricating dental implant abutments. In addition, the specimens were investigated by scanning electron microscopy (SEM) to determine the surface morphology. Twenty five discs (5 x 2 mm) of Ti-6Al-4V and Tilite (Ni-Cr-Ti) alloys were used in this study. Surface free energy was determined by the contact angle formed between a drop of distilled, deionized water and the surface of the specimen of each material. The surface roughness was measured with a mechanical profilometer and the surface hardness was evaluated by means of the Vickers hardness micro indentation test. SFE, SR and SH data were analyzed using one-way ANOVA (p < 0.05). Statistical differences (p < 0.05) were found between Ti-6Al-4V (36.2 erg x cm(-2); 0.2 microm) and Tilite (30.9 erg x cm(-2); 0.16 microm) for SFE and SR. However, the differences between the surface hardness values of Ti-6Al-4V (325.0 kg/mm(2)) and Tilite (324.3 kg/mm(2)) were not statistically significant (p > 0.05). Evaluations by SEM revealed different surface morphology. Within the limits of this study, it can be concluded that the Ti-6Al-4V and Tilite alloys showed differences in surface properties, except for surface hardness, suggesting that both alloys may be considered appropriate for producing abutments. Further studies are, however, necessary to elucidate the biological responses to implant abutments made with these alloys.

PMID: 17242790 [PubMed - indexed for MEDLINE]


Free Full Text ArticleEffect of metal priming agents on bonding characteristics of an acrylic resin...
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Effect of metal priming agents on bonding characteristics of an acrylic resin joined to SUS XM27 steel.

J Oral Sci. 2006 Dec;48(4):215-8

Authors: Ishikawa Y, Kawamoto Y, Koizumi H, Furuchi M, Matsumura H, Tanoue N

The purpose of the current study was to evaluate the effect of functional monomers contained in the primers on adhesive bonding of a steel alloy. SUS XM27 steel was primed with one of the following materials; Alloy Primer, Estenia Opaque Primer, and V-Primer. The functional monomers in the primers were a phosphate (10-methacryloyloxydecyl dihydrogen phosphate; MDP) and a thione (6-(4-vinylbenzyl-n-propyl) amino-1,3,5-triazine-2,4-dithione, -dithiol tautomer; VTD) for Alloy Primer, MDP alone for Estenia, and VTD alone for V-Primer. The steel disks were bonded with an acrylic resin (Unifast Trad), and bond strength was determined. Of the three primers, both the Alloy Primer (33.3 MPa) and Estenia Opaque Primer (33.9 MPa) materials exhibited far better post-thermocycling bond strength than V-Primer (0 MPa). It can be concluded that the phosphate MDP is effective, whereas the thione VTD is ineffective for bonding SUS XM27 steel.

PMID: 17220619 [PubMed - indexed for MEDLINE]


Free Full Text ArticleFracture resistance of various temporary crown materials.
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Fracture resistance of various temporary crown materials.

J Contemp Dent Pract. 2007 Jan 1;8(1):44-51

Authors: Yilmaz A, Bayda&#x15F; S

AIM: The aim of this study was to evaluate the fracture resistance of various provisional crown materials using an in vitro model test system. METHODS AND MATERIALS: In the present study polycarbonate crowns, prefabricated by the manufacturer (3M Polycarbonate Crown), and the temporary crowns, fabricated in the dental laboratory environment, were fabricated using bis-acryl composite (Protemp II), autopolymerizing PMMA resin (BISICO Temp S), and heat-polymerized PMMA resin (Major C&B-V Dentine). All temporary crowns were stored in distilled water for 24 hours at room temperature prior to testing. The crowns were seated on metal dies, fabricated from Cr-Co alloy (AZ Dental, Konstanz, Germany), and then tested using the indenter of a Hounsfield testing machine (Hounsfield Tensometer, Hounsfield Test Equipment, Raydon, England). The tip of the indenter was located at a position one-third of the way down the inciso-palatine surface at 135 masculine. The data were statistically analyzed for differences using one-way analysis of variance (ANOVA) and the Tukey HSD test (P < .05). Additionally, the types of failure obtained from the fracture load test were examined using 10x magnification with a stereo microscope. RESULTS: The results of the present study indicated polycarbonate crowns were significantly different from the BISICO Temp S, Protemp II, and Major C&B-V Dentine (P < .05) groups. CONCLUSION: This in vitro study shows polycarbonate crowns may be preferable to the other types of temporary crowns used in this study.

PMID: 17211504 [PubMed - indexed for MEDLINE]


Free Full Text ArticleMarginal and internal adaptation of commercially pure titanium and titanium-a...
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Marginal and internal adaptation of commercially pure titanium and titanium-aluminum-vanadium alloy cast restorations.

J Contemp Dent Pract. 2007 Jan 1;8(1):19-26

Authors: Al Wazzan KA, Al-Nazzawi AA

AIM: The purpose of this in vitro study was to investigate the marginal accuracy and internal fit of complete cast crowns and three-unit fixed partial dentures (FPDs) cast with commercially pure titanium (CPTi) and Titanium-Aluminum-Vanadium alloy (Ti-6Al-4V). METHODS AND MATERIALS: CPTi and Ti-6Al-4V alloy were used to cast twelve single crowns and twelve three-unit FPDs. A traveling microscope was used to measure marginal gap and discrepancies in internal fit. Two and one-way analysis of variance (ANOVA) analyses were used to determine the effects of the marginal and internal fit discrepancies. RESULTS: The Ti-6Al-4V alloy demonstrated a significantly smaller marginal gap than CPTi (P<0.0001). The recorded marginal discrepancies for both metals were within a clinically accepted range (<100 microm). The single crown fit discrepancy was significantly smaller than the three-unit FPD for both the CPTi and the Ti-6Al-4V alloy (P<0.0001). For the internal fit discrepancy, the occlusal surface showed the greatest gaps. CONCLUSIONS: The Ti-6Al-4V alloy demonstrated a better fit than CPTi. Single crowns showed an improved fit when compared with the three-unit FPD. Mid-occlusal internal gap demonstrated greater values than the axial internal gap. CLINICAL IMPLICATIONS: This in vitro study suggested marginal fit of complete crowns and three-unit FPDs cast by CPTi or Ti-6Al-4V alloy were within the range of what is clinically acceptable for longevity of restorations.

PMID: 17211501 [PubMed - indexed for MEDLINE]


Free Full Text ArticleAssessment of head wear more than ten years after total hip arthroplasty: 22-...
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Assessment of head wear more than ten years after total hip arthroplasty: 22-mm zirconia vs. metal heads.

Acta Med Okayama. 2006 Dec;60(6):311-8

Authors: Inoue A, Asaumi K, Endo H, Fujiwara K, Mitani S, Ozaki T

The present retrospective study assessed radiographs to determine socket wear in total hip arthroplasty (THA) with 22-mm zirconia or COP (Cobalt-Chrome alloy rich in Cobalt and Phosphorous) heads, and in cemented stems at more than 10 years after operation. Sockets of ultra high molecular weight polyethylene were used in each of two THA groups (13 hips each) in a clinical trial in our hospital between 1989 and 1990. Three observers carried out masked assessments of the radiographs. Upon final examination, there was no remarkable loosening in the zirconia or COP group, and no case had required revision surgery as of 2005. There was a statistically significant difference between the 2 groups in average annual linear wear, at 0.093 mm/year and 0.046 mm/year in the zirconia and COP groups, respectively. Volume wear and average annual volume wear were also significantly greater in the zirconia group despite its superior mechanical strength and toughness in vitro. Our present findings do not confirm early expectations of lower wear in long-term results of 22-mm zirconia femoral heads used in THA.

PMID: 17189974 [PubMed - indexed for MEDLINE]


Free Full Text ArticleIn vitro comparison of NiTi rotary instruments and stainless steel hand instr...
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In vitro comparison of NiTi rotary instruments and stainless steel hand instruments in root canal preparations of primary and permanent molar.

J Indian Soc Pedod Prev Dent. 2006 Dec;24(4):186-91

Authors: Nagaratna PJ, Shashikiran ND, Subbareddy VV

This study is an attempt to compare the NiTi rotary and K-files hand instrumentation on root canal preparation of primary and permanent molars for their efficiency in preparation time, instrument failure and shaping the canals. About 20 primary mandibular second molar (I) and 20 permanent mandibular first molar (II) were selected. Each was further divided into 10 for K-files (a) and 10 for NiTi (b) groups, respectively. Results showed that preparation time Ib Ia and IIab<IIa, which was highly significant. In instrument failure, Ia (40%), IIa (30%) showed more deformation but not fracture and Ib (10%), IIb (20%) showed fracture, but not deformation. Profiles showed good canal taper and smoothness compared to the K-files. To conclude profile 0.04 taper 29 series, prepared canal rapidly than conventional K-file with good taper, smoothness though the flow was not satisfactory. Instrument failure with K-files was less. In primary teeth preparation time, instrument failure with profile was less compared to the permanent. To conclude it's encouraging to use the profiles in primary teeth.

PMID: 17183182 [PubMed - indexed for MEDLINE]


Free Full Text ArticleCobalt-chromium head wear following revision hip arthroplasty performed after...
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Cobalt-chromium head wear following revision hip arthroplasty performed after ceramic fracture--a case report.

Acta Orthop. 2006 Oct;77(5):833-5

Authors: Hasegawa M, Sudo A, Uchida A

PMID: 17068720 [PubMed - indexed for MEDLINE]


Free Full Text ArticleSevere cobalt poisoning with loss of sight after ceramic-metal pairing in a h...
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Severe cobalt poisoning with loss of sight after ceramic-metal pairing in a hip--a case report.

Acta Orthop. 2006 Oct;77(5):830-2

Authors: Steens W, von Foerster G, Katzer A

PMID: 17068719 [PubMed - indexed for MEDLINE]


Free Full Text ArticleMetal release mechanisms in hip replacement.

Metal release mechanisms in hip replacement.

Acta Orthop. 2006 Oct;77(5):695-6

Authors: Virtanen S

PMID: 17068697 [PubMed - indexed for MEDLINE]


Free Full Text ArticleWhich orthodontic archwire sequence? A randomized clinical trial.
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Which orthodontic archwire sequence? A randomized clinical trial.

Eur J Orthod. 2006 Dec;28(6):561-6

Authors: Mandall N, Lowe C, Worthington H, Sandler J, Derwent S, Abdi-Oskouei M, Ward S

The aim of this study was to compare three orthodontic archwire sequences. One hundred and fifty-four 10- to 17-year-old patients were treated in three centres and randomly allocated to one of three groups: A = 0.016-inch nickel titanium (NiTi), 0.018 x 0.025-inch NiTi, and 0.019 x 0.025-inch stainless steel (SS); B = 0.016-inch NiTi, 0.016-inch SS, 0.020-inch SS, and 0.019 x 0.025-inch SS; and C = 0.016 x 0.022-inch copper (Cu) NiTi, 0.019 x 0.025-inch CuNiTi, and 0.019 x 0.025-inch SS. At each archwire change and for each arch, the patients completed discomfort scores on a seven-point Likert scale at 4 hours, 24 hours, 3 days, and 1 week. Time in days and the number of visits taken to reach a 0.019 x 0.025-inch SS working archwires were calculated. A periapical radiograph of the upper left central incisor was taken at the start of the treatment and after placement of the 0.019 x 0.025-inch SS wire so root resorption could be assessed. There were no statistically significant differences between archwire sequences A, B, or C for patient discomfort (P > 0.05) or root resorption (P = 0.58). The number of visits required to reach the working archwire was greater for sequence B than for A (P = 0.012) but this could not be explained by the increased number of archwires used in sequence B.

PMID: 17041083 [PubMed - indexed for MEDLINE]


Free Full Text ArticleThe effect of disinfectants and line cleaners on the release of mercury from ...
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The effect of disinfectants and line cleaners on the release of mercury from amalgam.

J Am Dent Assoc. 2006 Oct;137(10):1419-25

Authors: Batchu H, Chou HN, Rakowski D, Fan PL

BACKGROUND: Dental practices use disinfectants or line cleaners to flush dental unit wastewater lines to minimize odor generation, remove solid waste particles and remove biofilms in dental unit water lines (DUWLs). METHODS: The authors evaluated 47 disinfectants or line cleaners for their potential to release mercury from amalgam waste. They prepared each product concentration according to the manufacturer's recommendations and gently agitated it along with one amalgam specimen for 24 hours. They filtered the combined decanted liquid and rinse and analyzed it for mercury using modified U.S. Environmental Protection Agency method 245.1. RESULTS: Six preparations released significantly more mercury from amalgam (about 17 to 340 times) than did the deionized water control (P < .001). The amount of mercury released by the other disinfectants/line cleaners was not statistically different from that released by the control. The pH values of all preparations ranged from 1.76 to 12.35. CONCLUSION AND CLINICAL IMPLICATIONS: This study and other published reports have demonstrated that preparations containing chlorine release more mercury from amalgam than did some other products and the deionized water control. As a result, the use of these products is not recommended for treating dental office wastewater lines or DUWLs.

PMID: 17012722 [PubMed - indexed for MEDLINE]


Free Full Text Article[A comparison between the cast-bonded keeper with different dental alloys in ...
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[A comparison between the cast-bonded keeper with different dental alloys in the metallographic structure]

Shanghai Kou Qiang Yi Xue. 2006 Aug;15(4):416-8

Authors: Zheng YL, Wei B, Yao HX

PURPOSE: The aim of this study is to investigate the changes of the metallographic structure of the cast-bonded keeper when cast in varied temperatures. METHODS: Three groups were included in this study: the gold alloy group, the Ni-Cr alloy group and Ti group, with the Magdisc 500 keeper as the control group. Each sample that contained a Magdisc 500 keeper was fabricated with the cast-bonded technique. Then, the samples were fabricated into a metallographic sample by polishing, smoothing and cleaning. Each sample was observed under metallographic microscope. RESULTS: There were no significant changes in the crystal size between the keeper in the gold alloy group and that in the control group. In both of the Ni-Cr alloy group and Ti group, the crystal of the keeper became larger, and this was more evident in the latter group. CONCLUSION: The keeper varied in the metallographic structure if cast-bonded with gold alloy, Ni-Cr alloy or Ti metal. The higher the casting temperature, the larger the crystal of the keeper. The results suggest that the change in the gold group is less than that in the Ni-Cr alloy group and Ti metal group.

PMID: 16955171 [PubMed - in process]


Free Full Text ArticleImprovement of pseudoelasticity and ductility of Beta III titanium alloy--app...
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Improvement of pseudoelasticity and ductility of Beta III titanium alloy--application to orthodontic wires.

Eur J Orthod. 2007 Feb;29(1):8-13

Authors: Laheurte P, Eberhardt A, Philippe M, Deblock L

The pseudoelasticity of metastable Beta III titanium alloy (TMAtrade mark) used for orthodontic applications is obtained by cold wiredrawing. This wire has higher rigidity than cold-drawn NiTi (Nitinoltrade mark, superelastic NiTi SE) and lower recoverable deformation. The low ductility value of Beta III is due to the deformation imposed by wiredrawing. The aim of this research was to improve the behaviour of this alloy by modifying the microstructural parameters to decrease the rigidity and increase the recoverable deformation and ductility of the alloy. The effects of second phase precipitate, grain size, and deformation on the wire mechanical properties were also examined. The isothermal precipitation of alpha (alpha) or omega (omega(isoth)) phases precludes the expression of the pseudoelastic effect. The presence of an omega(isoth) phase considerably increases fracture strength, whereas the alpha phase strongly decreases the ductility and adversely affects the strain recovery (epsilon(r)). To control the grain size, the growth of the recrystallized grains was studied by considering several parameters, which are known to have an influence on grain size, including the cold rolled strain, the temperature, the time of annealing, and the initial grain size. A structure with coarse grains, quenched from a temperature higher than the beta transus (T(beta)), associated with a plastic pre-deformation, contributed to an improved pseudoelastic behaviour, due to the presence of a reversible martensite phase (alpha'') induced by the pre-deformation.

PMID: 16954181 [PubMed - indexed for MEDLINE]


Free Full Text ArticleImprovement of eczematous symptoms after removal of amalgam-like metal in alv...
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Improvement of eczematous symptoms after removal of amalgam-like metal in alveolar bone.

Bull Tokyo Dent Coll. 2006 Feb;47(1):13-7

Authors: Matsuzaka K, Mabuchi R, Nagasaka H, Yoshinari M, Inoue T

This case report describes a 55-year-old woman with an amalgam-like metal remaining in alveolar bone after root-end sealing in 1964, and who then developed eczematous facial symptoms from 2000 onwards. Removal of the amalgam-like metal material improved the symptoms.

PMID: 16924154 [PubMed - indexed for MEDLINE]


Free Full Text ArticleEvaluating amalgam separators using an international standard.
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Evaluating amalgam separators using an international standard.

J Am Dent Assoc. 2006 Jul;137(7):999-1005

Authors: Batchu H, Rakowski D, Fan PL, Meyer DM

BACKGROUND: Most amalgam particles generated during placement and removal of amalgam restorations are captured by chair-side traps and suction system traps and filters. Particles not captured can end up in the wastewater discharged from the dental office. Environmental initiatives to reduce the discharge of mercury-containing products such as dental amalgam waste into the environment have sparked interest in the use of amalgam separators. METHODS: The authors used International Organization for Standardization (ISO) Standard 11,143 for Amalgam Separators in a laboratory test to evaluate the amalgam removal efficiency of 13 commercially available amalgam separators and two commercially available filtration devices not marketed as amalgam separators but that have the potential to be used as such. RESULTS: All 13 amalgam separators and the two filtration devices exceeded the ISO Standard 11,143 requirement of 95 percent amalgam removal efficiency. The authors found statistical differences in the efficiency of the separators and filtration devices. No differences were found between the "empty" and "full" conditions for each separator. CONCLUSION AND CLINICAL IMPLICATIONS: This laboratory evaluation shows that amalgam separators and the filtration devices removed at least 97.05 percent of the amalgam in samples with particle-size distribution as specified in ISO Standard 11,143.

PMID: 16803827 [PubMed - indexed for MEDLINE]


Free Full Text Article[Improvement of metal artifacts in dental structures by X-ray CT: reconstruct...
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[Improvement of metal artifacts in dental structures by X-ray CT: reconstruction of transverse images using oblique images by gantry tilt scanning]

Nippon Hoshasen Gijutsu Gakkai Zasshi. 2006 Jun 20;62(6):863-6

Authors: Nakae Y, Sakamoto K, Minamoto T, Kotoura N, Ozaki T, Johkoh T

PMID: 16799415 [PubMed - indexed for MEDLINE]


Free Full Text ArticleSurvival of ART and amalgam restorations in permanent teeth of children after...
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Survival of ART and amalgam restorations in permanent teeth of children after 6.3 years.

J Dent Res. 2006 Jul;85(7):622-6

Authors: Frencken JE, Taifour D, van 't Hof MA

The null hypothesis tested was that there is no difference in the survival percentages of all restorations placed through the Atraumatic Restorative Treatment (ART) approach, with high-viscosity glass ionomer, and those produced through the traditional approach, with amalgam (TA), in the permanent dentitions of children after 6.3 years. Using a parallel group design, we randomly assigned a total of 370 children, aged 6 to 9 years, to the ART group and 311 children, also aged 6 to 9 years, to the TA group. Eight dentists placed a total of 1117 single- and multiple-surface restorations. The cumulative survival percentages for ART glass-ionomer restorations were statistically significantly higher than those of amalgam restorations at all time intervals except the first (p < or = 0.044). After 6.3 years, the cumulative survival percentages of ART and amalgam restorations were 66.1% (SE = 3.1%) and 57.0% (SE = 3.3%), respectively. We concluded that the restorations produced with the ART approach, with high-viscosity glass ionomer, survived longer than those produced with the traditional approach, with amalgam, in the permanent teeth of young children.

PMID: 16798862 [PubMed - indexed for MEDLINE]


Free Full Text ArticleMercury(II) ion-selective polymeric membrane sensors for analysis of mercury ...
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Mercury(II) ion-selective polymeric membrane sensors for analysis of mercury in hazardous wastes.

Anal Sci. 2006 Jun;22(6):877-81

Authors: Hassan SS, Mahmoud WH, Mohamed AH, Kelany AE

Two novel potentiometric sensors that are highly selective to Hg2+ ions are described. These are based on the use of 5,5'-dithio-bis(2-nitrobenzoic acid) (DTNB) and tricyclazole (TCZ) as neutral carriers in plasticized poly(vinyl chloride) membranes. Fast Nernstian responses are obtained for Hg2+ ions over the concentration ranges 7.0 x 10(-6) - 1.0 x 10(-2) and 7.7 x 10(-6) - 1.0 x 10(-2) mol l(-1) at pH 1.8 - 3.3 with lower detection limits of 5.0 x 10(-6) and 5.6 x 10(-6) mol l(-1) (approximately 1 microh ml(-1)) and calibration slopes of 30.0 and 29.7 mV decade(-1) with DTNB- and TCZ-based membrane sensors, respectively. Validation of the assay method reveals good performance characteristics, including long life span, good selectivity for Hg2+ ions over a wide variety of other metal ions, long term response stability, and high reproducibility. Applications for direct determination of mercury in hazardous wastes including dental amalgam, mercury bulbs, and fluorescent lamps give results with good correlation with data obtained using cold vapor atomic absorption spectrometry.

PMID: 16772689 [PubMed - indexed for MEDLINE]


Free Full Text ArticleMicrohardness of Ni-Cr alloys under different casting conditions.
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Microhardness of Ni-Cr alloys under different casting conditions.

Braz Oral Res. 2006 Jan-Mar;20(1):40-6

Authors: Bauer JR, Loguercio AD, Reis A, Rodrigues Filho LE

This study evaluated the microhardness of Ni-Cr alloys used in fixed prosthodontics after casting under different conditions. The casting conditions were: (1-flame/air torch) flame made of a gas/oxygen mixture and centrifugal casting machine in a non-controlled casting environment; (2-induction/argon) electromagnetic induction in an environment controlled with argon; (3-induction/vacuum) electromagnetic induction in a vacuum environment; (4-induction/air) electromagnetic induction in a non-controlled casting environment. The 3 alloys used were Ni-Cr-Mo-Ti, Ni-Cr-Mo-Be, and Ni-Cr-Mo-Nb. Four castings with 5 cylindrical, 15 mm-long specimens (diameter: 1.6 mm) in each casting ring were prepared. After casting, the specimens were embedded in resin and polished for Vickers microhardness (VH) measurements in a Shimadzu HMV-2 (1,000 g for 10 s). A total of 5 indentations were done for each ring, one in each specimen. The data was subjected to two-way ANOVA and Tukey's multiple comparison tests (alpha = 0.05). The VH values of Ni-Cr-Mo-Ti (422 +/- 7.8) were statistically higher (p < 0.05) than those of Ni-Cr-Mo-Nb (415 +/- 7.6). The lowest VH values were found for Ni-Cr-Mo-Be (359 +/- 10.7). The VH values obtained in the conditions induction/argon and induction/vacuum were similar (p > 0.05) and lower than the values obtained in the conditions induction/air and flame/air torch (p < 0.05). The VH values in the conditions induction/air and flame/air were similar (p > 0.05). The microhardness of the alloys is influenced by their composition and casting method. The hardness of the Ni-Cr alloys was higher when they were cast with the induction/air and flame/air torch methods.

PMID: 16729173 [PubMed - indexed for MEDLINE]


Free Full Text ArticleBond strength of three dental porcelains to Ni-Cr and Co-Cr-Ti alloys.
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Bond strength of three dental porcelains to Ni-Cr and Co-Cr-Ti alloys.

Braz Dent J. 2006;17(1):24-8

Authors: Fernandes Neto AJ, Panzeri H, Neves FD, Prado RA, Mendon&#xE7;a G

Ceramometal bond strength has played an important role for the replacement of gold alloys by nickel-chromium alloys in dentistry. This study evaluated the metal/porcelain bond strength of three ceramic systems (Vita VMK 88, Williams and Duceram) associated with three nickel-chromium alloys (Durabond, Lite Cast B and Resistal P) and one experimental cobalt-chromium-titanium alloy. Thirty cast cylinder specimens (15 mm in height; 6 mm in diameter) were obtained for each alloy, in away that 10 specimens of each alloy were tested with each porcelain. Bond strength was measured with an Emic screw-driven mechanical testing machine by applying parallel shear forces to the specimens until fracture. Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis of the alloy/ceramic combinations (p<0.05). Resistal P/Duceram had significantly higher bond strength (44.38+/-9.12 MPa) (p<0.05) than the other combinations, except for Co-Cr-Ti alloy/Vita VMK 88 (38.41+/-12.64 MPa). The association of the experimental Co-Cr-Ti alloy with Williams porcelain had significantly higher bond strength (28.20+/-3.86 MPa) than the combination of other alloys with the same porcelain (p<0.05). Based of these results and within the limitations of an in vitro study, it may be concluded that the bond strength of the three ceramic systems to the Ni-Cr and Co-Cr-Ti alloys varied significantly, indicating that metal/ceramic compatibility was very important to the bond strength.

PMID: 16721460 [PubMed - indexed for MEDLINE]


Free Full Text ArticleFlexural strength of pure Ti, Ni-Cr and Co-Cr alloys submitted to Nd:YAG lase...
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Flexural strength of pure Ti, Ni-Cr and Co-Cr alloys submitted to Nd:YAG laser or TIG welding.

Braz Dent J. 2006;17(1):20-3

Authors: Rocha R, Pinheiro AL, Villaverde AB

Welding of metals and alloys is important to Dentistry for fabrication of dental prostheses. Several methods of soldering metals and alloys are currently used. The purpose of this study was to assess, using the flexural strength testing, the efficacy of two processes Nd:YAG laser and TIG (tungsten inert gas) for welding of pure Ti, Co-Cr and Ni-Cr alloys. Sixty cylindrical specimens were prepared (20 of each material), bisected and welded using different techniques. Four groups were formed (n=15). I: Nd:YAG laser welding; II- Nd:YAG laser welding using a filling material; III- TIG welding and IV (control): no welding (intact specimens). The specimens were tested in flexural strength and the results were analyzed statistically by one-way ANOVA. There was significant differences (p<0.001) among the non-welded materials, the Co-Cr alloy being the most resistant to deflection. Comparing the welding processes, significant differences (p<0.001) where found between TIG and laser welding and also between laser alone and laser plus filling material. In conclusion, TIG welding yielded higher flexural strength means than Nd:YAG laser welding for the tested Ti, Co-Cr and Ni-Cr alloys.

PMID: 16721459 [PubMed - indexed for MEDLINE]


Free Full Text ArticleMRI comparison of periprosthetic structures around zirconium knee prostheses ...
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MRI comparison of periprosthetic structures around zirconium knee prostheses and cobalt chrome prostheses.

AJR Am J Roentgenol. 2006 Jun;186(6):1771-7

Authors: Raphael B, Haims AH, Wu JS, Katz LD, White LM, Lynch K

OBJECTIVE: The purpose of our study was to compare reviewer confidence and interobserver agreement in the evaluation of MR images of periprosthetic structures around zirconium total knee prostheses and cobalt chrome prostheses. MATERIALS AND METHODS: Three board-certified radiologists blinded to prosthesis type used identical MRI protocols to independently evaluate 21 total knee prostheses: 14 zirconium prostheses and seven cobalt chrome prostheses. The radiologists evaluated the following eight parameters: integrity of the medial and lateral collateral ligaments, the quadriceps and the patellar tendons, presence of a joint effusion, and for evidence of periprosthetic osseous signal abnormality around each of the three components. The reviewers gave their degree of confidence in evaluating each of the findings on a five-point scale, 0 being no confidence and 4 being high confidence in the finding. The degree of confidence was used as the vehicle for comparing the two groups of patients. RESULTS: The confidence ratings for all MRI variables were significantly higher for the zirconium group than for the cobalt chrome group. The confidence ratings varied less for the zirconium group than for the cobalt chrome group with an SD of 0.45 versus 0.95, respectively. There was greater interobserver agreement in the zirconium group (coefficient of interobserver agreement, 0.82 vs 0.35). The reviewers had the highest degree of confidence when examining for joint effusion in both groups (3.9 for the zirconium group; 3.7 for the cobalt chrome group). The greatest discrepancies between the two groups were in evaluation of periprosthetic osseous signal changes with the greatest difference being between the femoral component of each group with an average confidence rating of 3.3 for the zirconium group and 0.8 for the cobalt chrome group. CONCLUSION: Reviewers had significantly more confidence, less variability, and greater interobserver agreement in MRI evaluation of periprosthetic structures around zirconium knee prostheses than those around cobalt chrome knee prostheses.

PMID: 16714672 [PubMed - indexed for MEDLINE]


Free Full Text ArticleFixed space maintainers combined with open-face stainless steel crowns.
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Fixed space maintainers combined with open-face stainless steel crowns.

J Contemp Dent Pract. 2006 May 1;7(2):95-103

Authors: Yilmaz Y, Kocogullari ME, Belduz N

OBJECTIVE: This study investigates the clinical performance of fixed space maintainers placed on seriously damaged abutment teeth. METHODS: Crowns were placed on damaged abutment primary teeth. Fixed space maintainers were prepared by using rectangular wire between the window in the facial surface of the crowns and other abutment teeth and were subsequently bonded with a flowable resin composite. This procedure was introduced clinically, and the cases were observed over a period of twelve months. RESULTS: Twenty-seven fixed space maintainers (25 on lower jaw, two on upper jaw) were included in this study. No clinical failure was recorded in any of the cases in the observation time, and the rate of clinical performance was 100%. CONCLUSION: The study shows the effectiveness of fixed space maintainers combined with stainless steel crowns ("open-face fixed space maintainers") which were placed on primary molar teeth used as abutments in cases with extensive caries and loss of occlusogingival dimension.

PMID: 16685300 [PubMed - indexed for MEDLINE]


Free Full Text ArticleNeurobehavioral effects of dental amalgam in children: a randomized clinical ...
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Neurobehavioral effects of dental amalgam in children: a randomized clinical trial.

JAMA. 2006 Apr 19;295(15):1784-92

Authors: DeRouen TA, Martin MD, Leroux BG, Townes BD, Woods JS, Leit&#xE3;o J, Castro-Caldas A, Luis H, Bernardo M, Rosenbaum G, Martins IP

CONTEXT: Dental (silver) amalgam is a widely used restorative material containing 50% elemental mercury that emits small amounts of mercury vapor. No randomized clinical trials have determined whether there are significant health risks associated with this low-level mercury exposure. OBJECTIVE: To assess the safety of dental amalgam restorations in children. DESIGN: A randomized clinical trial in which children requiring dental restorative treatment were randomized to either amalgam for posterior restorations or resin composite instead of amalgam. Enrollment commenced February 1997, with annual follow-up for 7 years concluding in July 2005. SETTING AND PARTICIPANTS: A total of 507 children in Lisbon, Portugal, aged 8 to 10 years with at least 1 carious lesion on a permanent tooth, no previous exposure to amalgam, urinary mercury level <10 microg/L, blood lead level <15 microg/dL, Comprehensive Test of Nonverbal Intelligence IQ > or =67, and with no interfering health conditions. INTERVENTION: Routine, standard-of-care dental treatment, with one group receiving amalgam restorations for posterior lesions (n = 253) and the other group receiving resin composite restorations instead of amalgam (n = 254). MAIN OUTCOME MEASURES: Neurobehavioral assessments of memory, attention/concentration, and motor/visuomotor domains, as well as nerve conduction velocities. RESULTS: During the 7-year trial period, children had a mean of 18.7 tooth surfaces (median, 16) restored in the amalgam group and 21.3 (median, 18) restored in the composite group. Baseline mean creatinine-adjusted urinary mercury levels were 1.8 microg/g in the amalgam group and 1.9 microg/g in the composite group, but during follow-up were 1.0 to 1.5 microg/g higher in the amalgam group than in the composite group (P<.001). There were no statistically significant differences in measures of memory, attention, visuomotor function, or nerve conduction velocities (average z scores were very similar, near zero) for the amalgam and composite groups over all 7 years of follow-up, with no statistically significant differences observed at any time point (P values from .29 to .91). Starting at 5 years after initial treatment, the need for additional restorative treatment was approximately 50% higher in the composite group. CONCLUSIONS: In this study, children who received dental restorative treatment with amalgam did not, on average, have statistically significant differences in neurobehavioral assessments or in nerve conduction velocity when compared with children who received resin composite materials without amalgam. These findings, combined with the trend of higher treatment need later among those receiving composite, suggest that amalgam should remain a viable dental restorative option for children. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00066118.

PMID: 16622140 [PubMed - indexed for MEDLINE]


Free Full Text ArticleNeuropsychological and renal effects of dental amalgam in children: a randomi...
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Neuropsychological and renal effects of dental amalgam in children: a randomized clinical trial.

JAMA. 2006 Apr 19;295(15):1775-83

Authors: Bellinger DC, Trachtenberg F, Barregard L, Tavares M, Cernichiari E, Daniel D, McKinlay S

CONTEXT: No randomized trials have been published that address the concern that inhalation of mercury vapor released by amalgam dental restorations causes adverse health effects. OBJECTIVE: To compare the neuropsychological and renal function of children whose dental caries were restored using amalgam or mercury-free materials. DESIGN AND SETTING: The New England Children's Amalgam Trial was a 2-group randomized safety trial involving 5 community health dental clinics in Boston, Mass, and 1 in Farmington, Me, between September 1997 and March 2005. PARTICIPANTS AND INTERVENTION: A total of 534 children aged 6 to 10 years at baseline with no prior amalgam restorations and 2 or more posterior teeth with caries were randomly assigned to receive dental restoration of baseline and incident caries during a 5-year follow-up period using either amalgam (n=267) or resin composite (n =267) materials. MAIN OUTCOME MEASURES: The primary neuropsychological outcome was 5-year change in full-scale IQ scores. Secondary outcomes included tests of memory and visuomotor ability. Renal glomerular function was measured by creatinine-adjusted albumin in urine. RESULTS: Children had a mean of 15 tooth surfaces (median, 14) restored during the 5-year period (range, 0-55). Assignment to the amalgam group was associated with a significantly higher mean urinary mercury level (0.9 vs 0.6 microg/g of creatinine at year 5, P<.001). After adjusting for randomization stratum and other covariates, no statistically significant differences were found between children in the amalgam and composite groups in 5-year change in full-scale IQ score (3.1 vs 2.1, P = .21). The difference in treatment group change scores was 1.0 (95% confidence interval, -0.6 to 2.5) full-scale IQ score point. No statistically significant differences were found for 4-year change in the general memory index (8.1 vs 7.2, P = .34), 4-year change in visuomotor composite (3.8 vs 3.7, P = .93), or year 5 urinary albumin (median, 7.5 vs 7.4 mg/g of creatinine, P = .61). CONCLUSIONS: In this study, there were no statistically significant differences in adverse neuropsychological or renal effects observed over the 5-year period in children whose caries were restored using dental amalgam or composite materials. Although it is possible that very small IQ effects cannot be ruled out, these findings suggest that the health effects of amalgam restorations in children need not be the basis of treatment decisions when choosing restorative dental materials. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00065988.

PMID: 16622139 [PubMed - indexed for MEDLINE]


Free Full Text ArticleRemoval resistance of glass-fiber and metallic cast posts with different leng...
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Removal resistance of glass-fiber and metallic cast posts with different lengths.

J Oral Sci. 2006 Mar;48(1):15-20

Authors: Braga NM, Paulino SM, Alfredo E, Sousa-Neto MD, Vansan LP

This study evaluated the strength required to remove glass-fiber and metallic cast posts with different lengths. Sixty endodontically treated canines were included and their roots were embedded in acrylic resin after discarding the crowns. Samples were randomly assigned to 3 groups according to the post length (n = 20): I- 6 mm, II - 8 mm and III- 10 mm. Each group was divided into 2 subgroups based on the post material (n = 10): A- glass fiber or B- metallic cast. Post-space was prepared with Fibrekor Post Kit attached to a parallelometer. In subgroup A, prefabricated glass fiber posts from Fibrekor Post Kit were utilized. In metallic post group (subgroup B), an impression of post space was obtained, followed by casting. All posts were luted with Panavia F cement. A universal testing machine determined the force required to dislodge each post. ANOVA analysis indicated significant differences (P < 0.01) among post length. Tukey test showed that posts with 10 mm-length showed higher resistance on removal than posts with 6 mm-length. Posts with 8 mm-length did not exhibit difference when compared to 6 and 10 mm posts. No significant differences (P > 0.05) were observed between the tested post materials. It was concluded that the type of post did not influence the removal resistance and that posts with 10 mm-length required greater force to be dislodged.

PMID: 16617196 [PubMed - indexed for MEDLINE]


Free Full Text ArticleAmalgam matrix for class II and class V preparations connected at the proxima...
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Amalgam matrix for class II and class V preparations connected at the proximal box.

J Am Dent Assoc. 2006 Feb;137(2):186-9

Authors: Mamoun JS, Ahmed MK

BACKGROUND: The authors present a technique for placing and reinforcing an amalgam matrix around combined Class II and Class V preparations that connect at the proximal box. OVERVIEW: First, the dentist fills the Class V aspect of the preparation, using a temporary resin-based composite wall at the line angle to support amalgam condensation. The dentist then removes the wall and places a matrix band around the tooth, internally reinforcing the band with smaller pieces of matrix band and resin-saturated cotton balls that are light-polymerized and externally reinforcing the band with fast-polymerizing vinyl polysiloxane. Finally, the dentist condenses the line angle amalgam through the proximal box and condenses the proximal box and occlusal aspects. CONCLUSION: For connected Class II and Class V preparations, this matrix technique permits controlled amalgam condensation, even at the line angle aspect, where it is difficult to condense amalgam without voids or microleakage. CLINICAL IMPLICATIONS: This technique allows dentists to provide a stable, inexpensive direct restoration for teeth with connected Class II and Class V preparations, providing an alternative for patients who do not wish to have crowns placed.

PMID: 16521384 [PubMed - indexed for MEDLINE]


Free Full Text ArticleMethylmercury, amalgams, and children's health.
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Methylmercury, amalgams, and children's health.

Environ Health Perspect. 2006 Mar;114(3):A149; author reply A149-50

Authors: Guzzi G, Minoia C, Pigatto PD, Severi G

PMID: 16507443 [PubMed - indexed for MEDLINE]


Free Full Text ArticleInability of laser and rotary instrumentation to eliminate root canal infection.
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Inability of laser and rotary instrumentation to eliminate root canal infection.

J Am Dent Assoc. 2006 Jan;137(1):67-70

Authors: Jha D, Guerrero A, Ngo T, Helfer A, Hasselgren G

BACKGROUND: The authors evaluated the antibacterial effectiveness of laser instrumentation and rotary instrumentation of anterior, single-rooted teeth infected with Enterococcus faecalis. METHODS: The authors divided 35 infected samples into five groups: Group A: inoculation, laser, 17 percent ethylene-diamine-tetra-acetate (EDTA), 2.5 percent sodium hypochlorite (NaOCl) (n=10); Group B: inoculation, laser, 17 percent EDTA, sterile saline (n = 10); Group C: inoculation, rotary, 17 percent EDTA, 2.5 percent NaOCl (n=10); Group D: inoculation, no instrumentation (positive control) (n=5); Group E: no inoculation, no instrumentation (negative control) (n=5). They sampled and incubated dentin shavings from each canal for bacterial growth. RESULTS: In Group A, eight tubes were positive for bacterial growth. In Group B, 10 tubes were positive for bacterial growth. In Group C, six tube were positive for bacterial growth. In Group D, all of the tubes were positive for bacterial growth. In Group E, no tubes showed bacterial growth. The Fisher exact test showed no significant differences among groups A, E and C. CONCLUSION: Neither the laser nor the rotary instrumentation was able to eliminate endodontic infection. CLINICAL IMPLICATIONS: Although lasers have been presented as high-tech tools for disinfecting root canals, the laser was ineffective in this study.

PMID: 16457001 [PubMed - indexed for MEDLINE]


Free Full Text ArticleEffects of a segmented removable appliance in molar distalization.
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Effects of a segmented removable appliance in molar distalization.

Eur J Orthod. 2006 Feb;28(1):65-73

Authors: Akin E, Gurton AU, Sagdic D

The aim of the present investigation was to evaluate the skeletal and dentoalveolar treatment effects of a segmented removable appliance [removable molar distalizer (RMD)] for molar distalization. The study was conducted on 28 patients (12 females and 16 males), with a mean age of 11.8 years. All presented with a skeletal Class I malocclusion and a bilateral dental Class II molar relationship. The pre- and post-distalization records included lateral head films, study models and standard photographs. The findings were evaluated with a paired samples t-test. The average maxillary first molar distalization with the RMD was 3.98 mm, with 4.61 degrees of distal tipping. The maxillary second premolars drifted distally 2.13 mm on average with 1.54 degrees of distal tipping, while the maxillary first premolars showed 1.23 mm of mesial movement and 1.98 degrees of mesial tipping. The incisors protruded 1.09 mm with 1.27 degrees of labial tipping. The RMD was effective in distal molar movement and all patients attained a bilateral Class I molar relationship in an average period of 4.5 months. Hygiene problems and mucosal irritations, frequently found with fixed intraoral distalization techniques, were not observed during the distalization period.

PMID: 16436365 [PubMed - indexed for MEDLINE]


Free Full Text ArticleEffect of metal conditioners on polymerization behavior of bonding agents.
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Effect of metal conditioners on polymerization behavior of bonding agents.

J Oral Sci. 2005 Dec;47(4):171-5

Authors: Yoshida T, Yamaguchi K, Tsubota K, Takamizawa T, Kurokawa H, Rikuta A, Ando S, Miyazaki M

This study aimed to determine the influence of metal conditioners on the polymerization behavior of bonding agents. Bonding agents of two-step self-etching primer systems and metal conditioners for adhesion of dental metal alloys were used. Double bond conversion was determined by Fourier transform-ation infrared spectroscopy. The percentage of residual double bonds, including pendant and monomeric double bonds, was calculated by comparing the obtained ratio with that of the uncured bonding agent. The degree of conversion of the bonding agents was obtained by subtracting the remaining double bonds from 100%. ANOVA followed by a Tukey HDS test was performed. Degree of conversion of the bonding agents ranged from 86.0 to 87.8%. When the bonding agents were mixed with metal conditioners or solvents of the metal conditioners, double bond conversion of the bonding agents tended to decrease. Within the limitations of this study, which was far removed from clinical situations, the presence of metal conditioners and remaining solvents had adverse effects on the polymerization reaction of bonding agents. Clinicians should be cognizant of the various factors that can influence bond strength of restorative resins to dentin.

PMID: 16415560 [PubMed - indexed for MEDLINE]


Free Full Text ArticleMetal type of the femoral stem in total hip arthroplasty.
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Metal type of the femoral stem in total hip arthroplasty.

Medicina (Kaunas). 2005;41(11):932-5

Authors: Tarasevicius S, Tarasevicius R, Zegunis V, Smailys A, Kalesinskas RJ

OBJECTIVE: To compare the influence of two different cemented stems each made of different alloys on survival and outcome. MATERIAL AND METHODS: We analyzed 341 total hip replacements performed in 1998-2001. Two types of prostheses were implanted. Biomet Bi-Metric titanium stem, cobalt-chrome head and ultra high molecular weight all poly cup were implanted in 102 cases. Aesculap Centrament cobalt-chrome stem, head and ultra high molecular weight all poly cup were implanted in 239 cases. All prostheses were cemented; Palacos bone cement with gentamycin was used in all cases. Cementing technique was consistent in all cases. All data were collected prospectively. For every total hip replacement the form was filled in. The documental patients' data, implant type, cement type, cementing technique, intraoperative and postoperative complications were registered. All revision surgeries were registered; the patients' death dates were recorded from national register database up to December 31, 2004. Kaplan-Meier curves were used to calculate implant survival rates. RESULTS: The total implant survival for Biomet Bi-metric prostheses was 98%, 7 years postoperatively. The total implant survival as Aesculap Centrament prostheses were used was 98%, 6 years postoperatively. CONCLUSION: The mid-term implant survival of Biomet Bi-Metric titanium stems was the same as survival of Aesculap Centrament cobalt-chromium stems.

PMID: 16333216 [PubMed - indexed for MEDLINE]


Free Full Text ArticleEfficacy of ultrasound in removal of intraradicular posts using different tec...
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Efficacy of ultrasound in removal of intraradicular posts using different techniques.

J Oral Sci. 2005 Sep;47(3):117-21

Authors: Braga NM, Alfredo E, Vansan LP, Fonseca TS, Ferraz JA, Sousa-Neto MD

The efficacy of ultrasound in removing cast metal posts was evaluated in this in vitro study using one or two ultrasound units and ultrasonic vibration for various lengths of time. The crowns of 30 healthy maxillary canines were removed, the roots were embedded in acrylic resin blocks, and the root canals were treated endodontically. The canals were prepared and their impressions were taken with self-curing acrylic resin. After casting with copper-aluminum alloy, the posts were blasted with aluminum oxide and cemented with Panavia F resin cement. The specimens were divided into five groups. In groups I and II, only one ultrasound unit was used for 30 and 60 s, respectively; in groups III and IV, two ultrasound units were used simultaneously for 30 and 60 s, respectively; in group V, ultrasound was not used (control). Ultrasonic vibrations were applied with an Enac OE-5 ultrasound unit and an ST-09 tip. All samples were subjected to traction on an Instron machine (model 4444) at a cross-head speed of 1 mm/min. Analysis of the results revealed a statistically significant difference between the groups (ANOVA, P < 0.01); however the difference between groups II and IV was not statistically significant. The efficacy of ultrasound in removing intraradicular posts was confirmed, and the most effective technique was the use of two ultrasound units, independent of the length of time ultrasound was applied.

PMID: 16313088 [PubMed - indexed for MEDLINE]


Free Full Text ArticleThe color differences between different thicknesses of resin veneered over am...
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The color differences between different thicknesses of resin veneered over amalgam.

J Contemp Dent Pract. 2005 Nov 15;6(4):38-45

Authors: Al-Jazairy YH, El-Hejazi AA

STATEMENT OF PROBLEM: Composites and compomers are popular in dental practice. However, little is known about their esthetic appearance as veneering restorative materials over amalgam restorations. PURPOSE: This in vitro study was designed to assess the color differences of composite and compomer restorative materials, placed in thicknesses of 1 mm and 2 mm over amalgam. MATERIAL AND METHODS: Thirty six cylindrical Teflon molds were filled with amalgam (13 mm diameter, 2 mm thickness) and stored at 37 degrees C and 100% relative humidity for 7 days. Nine veneers (for each thickness of 1 and 2 mm) were fabricated from four types of tooth-colored restorative material, Dyract AP (DYR), Compoglass F (COMP), Herculite XRV (XRV), and Vitalecense (VIT), over amalgam specimens using Teflon-split molds and following the manufacturers' instructions. A spectrophotometer was used to measure the color difference DeltaE* between the two thicknesses. RESULTS: Color difference DeltaE* values for 1 mm thickness veneers [XRV (2.52), Comp (5.46), VIT (6.73), and DYR (6.88)] were statistically significantly higher than the 2 mm thickness [XRV (1.32), Comp (3.24), VIT (4.89), and DYR (4.83)]. Although the XRV material had the lowest DeltaE* values, no statistically significant difference was found between the two thicknesses. The color measurements at L*, a*, and b* showed most materials became darker in color at either thickness. CONCLUSION: The thicker veneer specimens were found to be closer in color to the controls than the thinner specimens. Only XRV had color differences (DeltaE*) small enough to be considered clinically acceptable (2.52 and 1.32 at 1 mm and 2 mm, respectively). CLINICAL IMPLICATIONS: In this in vitro study the color of XRV was affected the least when veneered on amalgam. Opaquers may be needed to be used with thinner veneers to minimize the effect of amalgam background.

PMID: 16299605 [PubMed - indexed for MEDLINE]


Free Full Text ArticleThe significance of marginal gap and overextension measurement in the evaluat...
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The significance of marginal gap and overextension measurement in the evaluation of the fit of complete crowns.

J Contemp Dent Pract. 2005 Nov 15;6(4):26-37

Authors: Boeckler AF, Stadler A, Setz JM

INTRODUCTION: An important criterion for the success of a crown is marginal fit. However, in the patient's mouth fit can only be evaluated by subjective methods. This study describes the correlation between objective marginal fit and its subjective evaluation by dentists and dental technicians. MATERIALS AND METHODS: Thirty human premolars and molars were randomly divided into six groups and prepared with a shoulder. For each of the six groups, complete crowns were made of different alloys and technologies (casting: AuAgCu, AuPdPt, PdAgAu, CoCrMo, and Ti; milling: Ti). The crowns were cemented with provisional cement. Ten dentists and 10 technicians were asked to evaluate the fit of the crowns with a new dental explorer. The crowns were then cleaned and cemented with a zinc-oxide-phosphate-cement. The marginal gap and a possible overextended margin of the crowns were examined under a special 4x light microscope with a magnification level of 560 X. The means of the gaps and the overextended margins were calculated for each group. Significances were detected by analysis of variance (ANOVA) and the post-hoc-test (Bonferroni, p<0.05). Correlations between objective measuring and subjective evaluation were evaluated using the Pearson test. The influence of the measured values on the subjective evaluation was determined by regression analyses. RESULTS: Crowns made from different alloys and technologies showed partly significantly (p<0.05) different marginal gaps (mean ranging from 35 microm to 92 microm) and significantly (p<0.05) different overextended margins (mean ranging from 40 microm to 149 microm). There were significant correlations (p<0.05) between subjective findings and objective data. Significant correlations (p<0.01) were also found between the subjective findings of dentists and technicians. Compared to the marginal gap, only the overextended margin had a significant influence (p=0.00) on the subjective evaluations of the clinicians. CONCLUSION: Crowns from different alloys and technologies showed differences in marginal fit. Marginal gap and the overextension of the crowns significantly correlated with the subjective evaluation of their fit by dentists and dental technicians. For the decision of the clinicians, whether a crown is acceptable, overextension was more important than marginal gap.

PMID: 16299604 [PubMed - indexed for MEDLINE]


Free Full Text ArticleEvaluation of the castability of a Co-Cr-Mo-W alloy varying the investing tec...
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Evaluation of the castability of a Co-Cr-Mo-W alloy varying the investing technique.

Braz Dent J. 2005;16(1):50-5

Authors: Carreiro Ada F, Ribeiro RF, Mattos Mda G, Rodrigues RC

The purpose of this study was to compare the castability of Co-Cr-Mo-W (Remanium 2000), Ni-Cr (Durabond) and Co-Cr-Mo (Vera PDI) alloys invested with either conventional (phosphate- and silica-based) or mixed investing techniques. A 10 X 10 mm square-shaped nylon net containing 100 open squares served as a template for construction of wax patterns, which were invested with phosphate-based investment (Termocast), silica-based investment (Refrafil) and mixed investing technique (2-mm layer phosphate investment plus filling with silica investment). Forty-five cast specimens (5 per experimental condition) were obtained and sandblasted with aluminum oxide. The number of completely reproduced cast segments was counted to obtain a percentage designated "castability value", which indicated the accuracy of the alloy to reproduce mold details. Statistical analysis using two-way ANOVA and Tukey's test showed that, comparing the alloys, Remanium 2000 had statistically similar castability (p>0.05) to Vera PDI and lower than Durabond (p<0.05). Considering the mixed technique results, Remanium 2000 yielded lower castability value (p<0.05) than Durabond and Vera PDI alloys, which showed similar results to each other (p>0.05). In conclusion, the castability of the Co-Cr-Mo-W alloy (Remanium 2000) was comparable to that of the Co-Cr alloy (Vera PDI) and worse than that of the Ni-Cr alloy (Durabond). Except for Remanium 2000, the mixed investing technique considerably improved the accuracy of the alloys to reproduce cast details, compared to the phosphate-based investment. The mixed investing technique appears as a viable alternative to improve castability of base metal alloys without decreasing the surface quality of the metallic pieces.

PMID: 16113934 [PubMed - indexed for MEDLINE]


Free Full Text ArticleIon release and cytotoxicity of stainless steel wires.
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Ion release and cytotoxicity of stainless steel wires.

Eur J Orthod. 2005 Dec;27(6):533-40

Authors: Oh KT, Kim KN

Heat treatment is generally applied to orthodontic stainless steel (SS) wires to relieve the stresses that result from their manipulation by orthodontists. The quality and thickness of the oxide films formed on the surface of heat-treated wires can vary, and it is believed that these oxide films can influence the properties of heat-treated wires. The aim of this study was to investigate the influence of heat treatment and cooling methods on the amount of metal ions released and to examine the cytotoxicity of heat-treated wires. In this study, four types of SS wires (Remanium, Permachrome, Colboloy and Orthos) with a cross-sectional area of 0.41 x 0.56 mm were investigated. These wires were heat-treated in a vacuum, air, or argon environment, and were cooled in either a furnace or a water bath. Four control groups and 24 experimental groups were classified according to the type of wires, heat treatment conditions and cooling methods. In each group, the amount of nickel released as well as its cytotoxicity was investigated. The concentration of dissolved nickel ions in artificial saliva was measured for a period of up to 12 weeks. In all groups, the concentration of dissolved nickel ions in artificial saliva was lowest for the vacuum heat treatment-furnace cooling group and a significant difference was shown compared with the other experimental groups. The concentration of dissolved nickel ions in artificial saliva was highest in the groups heat-treated in air (P < 0.05), while the amount of nickel released was highest in the Remanium and Colboloy (P < 0.05). The cytotoxicity was mild in all the experimental groups but the response index of the air groups was slightly higher than in the other groups. According to these results, SS wires retain their high corrosion resistance and low ion release rate when heat-treated in a vacuum and cooled in a furnace.

PMID: 16093259 [PubMed - indexed for MEDLINE]


Free Full Text ArticleDisinfectants' effect on mercury release from amalgam.
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Disinfectants' effect on mercury release from amalgam.

J Am Dent Assoc. 2005 Jul;136(7):915-9

Authors: Roberts HW, Marek M, Kuehne JC, Ragain JC

BACKGROUND: Mercury environmental discharge is under increased scrutiny by the U.S. Environmental Protection Agency (EPA). Dental amalgam should be processed properly to prevent an additional environmental burden. Some processing agencies require that submitted amalgam be noninfectious. Investigations have demonstrated that oxidizing disinfectants mobilize mercury from amalgam into solution and add mercury to the environmental burden if it is disposed of improperly. The authors conducted a study to evaluate the effect of representative disinfectants on amalgam mercury release. METHODS: The authors sized a high-copper spherical amalgam alloy to match that typically found in dental unit suction traps. They exposed 20 grams of the alloy to several disinfectant solutions and evaluated the filtered supernatant solution for mercury content. RESULTS: Chlorine disinfectant materials discharged the most mercury ions, followed by bromide, iodophor, peroxide/peracetic acid and phenolic disinfectants. The quaternary ammonium compound did not discharge mercury ions above the detection limit (0.2 parts per billion) into solution. CONCLUSIONS: A quaternary ammonium compound did not mobilize mercury ions into solution when used as a disinfectant agent for amalgam. Chlorine disinfectants mobilized mercury ions the most, followed by bromide, iodophor, peroxide/peracetic acid and phenolic disinfectants. CLINICAL IMPLICATIONS: Dentists are obligated to be good environmental stewards and should follow practices that reduce environmental mercury release. Dental personnel should be aware that oxidizing disinfectants mobilize mercury ions into solution, which will be added to the environment if they are processed improperly. If required by processing, dental personnel should consider the different oxidizing effects of commonly used disinfectants.

PMID: 16060472 [PubMed - indexed for MEDLINE]



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