Fracture resistance of various temporary crown materials.

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

Authors: Yilmaz A, Baydaş 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]

The radiographic outcomes of direct pulp-capping procedures performed by dental students: a retrospective study.

J Am Dent Assoc. 2006 Dec;137(12):1699-705

Authors: Al-Hiyasat AS, Barrieshi-Nusair KM, Al-Omari MA

BACKGROUND: The decision between pulp capping and root canal therapy after pulp exposure is a clinical issue. The aim of the authors' study was to evaluate the outcome of direct pulp-capping procedures performed by dental students. METHODS: The authors followed the treatment outcomes of 193 patients with 204 pulp exposures with direct pulp capping. They determined the outcome of pulp capping radiographically using periapical radiographs taken at least three years after pulp exposure. The outcome was considered as successful if the tooth was present and not associated with periapical radiolucency or root canal treatment; otherwise, the outcome was considered as being a failure. RESULTS: Overall, the success rate of pulp capping was 59.3 percent. The success was associated more with mechanical exposure than with carious exposure (92.2 versus 33.3 percent) (P < .001), more with permanent restoration than with temporary restoration (80.8 versus 47.3 percent) (P < .001) and more with class I occlusal restoration (83.8 percent) than with proximal multiple surface restorations (Class II, 56.1 percent; Class III, 58.8 percent; mesial-occlusal-distal, 28.6 percent) (P = .009). Patients' age, sex, and tooth location and position had no significant effect on the outcome (P > .05). CONCLUSION: The success rate of direct pulp capping was 92.2 percent with mechanical exposure and 33.3 percent with carious exposure. CLINICAL IMPLICATIONS: Direct pulp capping is recommended after mechanical exposure with immediate placement of permanent restoration, while root canal therapy would be the choice of treatment if the exposure was due to caries.

PMID: 17138715 [PubMed - indexed for MEDLINE]

One-year clinical evaluation of two resin composites, two polymerization methods, and a resin-modified glass ionomer in non-carious cervical lesions.

J Contemp Dent Pract. 2006 Nov 1;7(5):42-53

Authors: Koubi S, Raskin A, Bukiet F, Pignoly C, Toca E, Tassery H

AIM: The aim of this study was to examine clinically relevant data on four restorative procedures for non-carious cervical lesions using United States Public Health Service (USPHS)-compatible clinical and photographic criteria and to compare different methods of analyzing clinical data. METHODS AND MATERIALS: Fourteen patients with at least one or two pairs of non-carious lesions under occlusion and a mean age of 50 were enrolled in this study. A total of 56 restorations (14 with each material) were placed by three experienced, calibrated dental practitioners. Two other experienced and calibrated practitioners, under single-blind conditions, followed up on all restorations for a period of one year. Three materials were randomly placed: a micro-hybrid composite with two polymerization methods (G1 and G2), a flowable micro-hydrid composite (G3), and a resin-modified glass ionomer (G4). Statistical analysis was performed using the Kruskall-Wallis test (p<0.05) and a Mann-Whitney U modified test with a corrected significance level. RESULTS: At the one year evaluation time, there were no restorations with secondary caries and the retention rates in G1 (IntenS with a hard polymerization), G2 (IntenS with a soft polymerization), G3 (Filtek flow), and G4 (Fuji II LC) were 85.7% (two losses), 92.8% (one loss), 100%, and 100%, respectively. The total visual comparison of the results at baseline (15 days later) showed significant differences only with the clinical acceptance criterion: G1 was different from G2, with a soft polymerization device (p<0.05). In terms of surface quality at one year, G1, G2, and G3 exhibited a statistically significant difference from G4, p<0.05. The digital analysis at baseline showed significant differences only with the clinical acceptance criterion: G1=G2 was different from G3=G4, p<0.05. At one year, only the microporosity criterion showed any statistical differences: G1=G2=G3 was different from G4, p<0.05. CONCLUSIONS: The resin-modified glass ionomer was easier to use and had a high retention rate, but it failed in terms of surface quality (visual mode) and porosity (digital mode) criteria compared to the others groups. Overall results showed no difference between groups G1 (hard-polymerized) and G2 (soft-polymerized), and only G1 was affected by the marginal edge (p<0.03) and integrity criteria (p<0.02) at one year.

PMID: 17091139 [PubMed - indexed for MEDLINE]

A clinical evaluation of resin-based composite and glass ionomer cement restorations placed in primary teeth using the ART approach: results at 24 months.

J Am Dent Assoc. 2006 Nov;137(11):1529-36

Authors: Ersin NK, Candan U, Aykut A, On&#xE7;ağ O, Eronat C, Kose T

BACKGROUND: The authors evaluated the 24-month performance of a packable resin-based composite/dentin bonding system and a high-viscosity glass ionomer cement (GIC) in restorations placed in primary molars with the atraumatic restorative treatment (ART) approach. METHODS: Three dentists placed 419 restorations in 219 children aged 6 through 10 years who had bilateral matched pairs of carious posterior Class I and II primary teeth. They used a split-mouth design to place the two materials, which were assigned randomly to contralateral sides. The authors evaluated the restorations according to U.S. Public Health Service Ryge criteria. RESULTS: After 24 months, 96.7 percent of the Class I GIC restorations and 91 percent of the resin-based composite restorations survived, while the success rates for the Class II restorations were 76.1 percent and 82 percent for the GIC and resin-based composite restorations, respectively. The survival rate of the Class II resin-based composite restorations was 5.9 percent higher than that of the GIC restorations at the 24-month evaluation, but this difference was not statistically significant. However, the study results showed a statistically significant difference in survival rates between Class I and II restorations for both materials. CONCLUSION AND CLINICAL IMPLICATIONS: The two-year clinical performance of both materials was satisfactory for the restoration of Class I and II primary molars using the ART approach.

PMID: 17082278 [PubMed - indexed for MEDLINE]

Survival analysis of complete veneer crowns vs. multisurface restorations: a dental school patient population.

J Dent Educ. 2006 Oct;70(10):1098-104

Authors: Janus CE, Unger JW, Best AM

The purpose of this study was to compare the longevity of crowns versus large multisurface restorations in posterior teeth. The investigation used the treatment database at Virginia Commonwealth University School of Dentistry. The inclusion criteria for the final data set used for analysis were: only one restored tooth per patient, premolars with three or more restored surfaces, molars with four or more restored surfaces, molars and premolars restored with complete veneer metal crowns, or crowns veneered with metal and porcelain. The Kaplan-Meier approach was used to visualize the survival curves, and the Cox proportional hazards model was used for analysis of predictor variables. The investigation indicates crowns survive longer than large restorations and premolar restorations survive longer than molar restorations. The median survival for crowns exceeded 16.6 years, with the median survival of premolar restorations being 4.4 years and molar restorations 1.3 years. An interaction between age and treatment was discovered, with overall survival decreasing as patient age increases. The doctor supervising the treatment also affected survival with treatment supervised by specialists lasting longer than treatment supervised by nonspecialists.

PMID: 17021290 [PubMed - indexed for MEDLINE]

ART and conventional root restorations in elders after 12 months.

J Dent Res. 2006 Oct;85(10):929-32

Authors: Lo EC, Luo Y, Tan HP, Dyson JE, Corbet EF

Successful use of atraumatic restorative treatment (ART) in children has been reported, but little information is available regarding its use in older adults. The hypothesis of this study was that survival rates of root restorations placed by both ART and the conventional technique were similar. Root-surface caries lesions in 103 institutionalized elders in Hong Kong were treated randomly by either: (1) the conventional approach-caries removed by dental burs, and the cavity filled with light-cured resin-modified glass ionomer; or (2) the ART approach-caries removed by hand instruments, and the cavity filled with chemically cured high-strength glass ionomer. In total, 84 conventional and 78 ART restorations were placed. After 12 months, 63 conventional and 59 ART restorations were reviewed, and the respective 12-month survival rates were 91.7% and 87.0% (p > 0.05). It is concluded that the survival rates of both types of root restorations were high and similar.

PMID: 16998134 [PubMed - indexed for MEDLINE]

Clinical performance of chairside CAD/CAM restorations.

J Am Dent Assoc. 2006 Sep;137 Suppl:22S-31S

Authors: Fasbinder DJ

BACKGROUND: The CEREC system (Sirona Dental Systems GmbH, Bensheim, Germany) is marking its 20th year of clinical service. The author reviews the literature on the effectiveness of this chairside CAD/CAM system. TYPES OF STUDIES REVIEWED: The author identified and reviewed clinical studies from 1985 through 2006 that included CEREC-generated inlays, onlays or crowns. These studies were conducted in both private practice and university settings. The author summarized the findings as they relate to postoperative sensitivity, restoration fracture, color match, margin adaptation and clinical longevity. RESULTS: Although postoperative sensitivity was reported, it was due to mainly occlusal interferences. Long-term postoperative sensitivity was not a reported problem. Similar to other ceramic restorations, restoration fracture is the primary mode of failure for CEREC-generated restorations. Although margin wear is detected consistently, consequences of the wear leading to restoration failure were reported rarely. The survival probability of CEREC-generated restorations was reported to be approximately 97 percent for five years and 90 percent for 10 years. CLINICAL IMPLICATIONS: The low rate of restoration fracture and long-term clinical survivability document the effectiveness of the CEREC system as a dependable, esthetic restorative option for patients.

PMID: 16950934 [PubMed - indexed for MEDLINE]

Adhesive analysis of voids in Class II composite resin restorations at the axial and gingival cavity walls restored under in vivo versus in vitro conditions.

Dent Mater. 2007 Jul;23(7):871-7

Authors: Purk JH, Dusevich V, Glaros A, Eick JD

OBJECTIVES: Adhesive analysis, under the scanning electron microscope of microtensile specimens that failed through the adhesive interface, was conducted to evaluate the amount of voids present at the axial versus gingival cavity walls of class II composite restorations restored under in vivo and in vitro conditions. METHODS: Five patients received class II resin composite restorations, under in vivo and in vitro conditions. A total of 14 premolar teeth yielded 59 (n=59) microtensile adhesive specimens that fractured through the adhesive interface. The fractured surfaces of all specimens were examined and the % area of voids was measured. RESULTS: Voids at the adhesive joint were highly predictive of bond strengths. An increase in the number of voids resulted in a decrease in the microtensile bond strength. The area of voids at the adhesive interface was as follows: in vivo axial 13.6+/-25.6% (n=12); in vivo gingival 48.8+/-29.2% (n=12); in vitro axial 0.0+/-0.0% (n=19) and in vitro gingival 11.7+/-17.6% (n=16). SIGNIFICANCE: Composite resin may bond differently to dentin depending upon the amount of voids and the cavity wall involved. The bond to the gingival wall was not as reliable as the bond to the axial wall. An increase in the amount of surface voids was a major factor for reducing microtensile bond strengths of adhesive to dentin.

PMID: 16950506 [PubMed - indexed for MEDLINE]

Effect of enamel preparations on fracture resistance of composite resin buildup of fractures involving dentine in anterior bovine teeth: an in vitro study.

J Indian Soc Pedod Prev Dent. 2006 Jun;24(2):69-75

Authors: Gandhi K, Nandlal B

Sixty bovine teeth with simulated mesio-incisal angle fracture were randomly and equally divided in one untreated (control) group and three experimental groups (Bevel, Chamfer and newly introduced Stair-step Chamfer preparation group) to evaluate the effect of enamel preparations on the fracture resistance of composite resin. Post restoration, fracture mechanics approach was used to quantify the failure of composite resins in testing the samples in Instron testing machine. Mean peak failure load (Newton) of composite amongst experimental groups was observed in the order; Chamfer (326.09 +/- 72.73), Stair-step chamfer (315.21 +/- 81.77) and Bevel (253.83 +/- 67.38). Results of the One-Way ANOVA revealed significant difference in the mean peak failure load values of the four different groups. (P<0.001) Scheffe's Post-Hoc comparison test (Subset for alpha = 0.05) revealed that there was no significant difference in the mean peak failure load values of the bevel, stair-step chamfer and chamfer preparation when considered together, but the mean peak values of control group (605.22 +/- 48.96) were observed significantly higher. Failure mode evaluation revealed, majority of failures occurred as cohesive and mixed type for all the experimental groups. Adhesive type failure was observed maximum (33%) in the bevel group. Stair-step chamfer preparation showed greatest potential for application and use as it no only demonstrated comparable values to Chamfer preparation ['t' value (0.39) (P > 0.05)] but also involved sacrificing less amount of tooth structure adjacent to fractured edge.

PMID: 16823230 [PubMed - indexed for MEDLINE]

An in vitro assessment of prefabricated fiber post systems.

J Am Dent Assoc. 2006 Jul;137(7):1006-12

Authors: Teixeira EC, Teixeira FB, Piasick JR, Thompson JY

BACKGROUND: The authors conducted a study to characterize the in vitro retention, fracture and light transmission behavior of four different fiber-reinforced resin-based composite root canal posts. METHODS: The authors divided 44 teeth into four groups according to the type of post they would receive: parallel fiberglass posts, double-tapered fiber quartz posts, tapered fiberglass posts and two different types of parallel fiberglass posts. They prepared teeth and cemented posts with dual-cured resin cement. After the specimens aged, the authors conducted pull-out tests. For fracture testing, they loaded posts at 45 degrees in a universal testing machine. They determined load-to-fracture values and relative stiffness. They measured percentage of light transmission by means of a light microscope coupled with a spectrometer. RESULTS: Both tapered posts showed lower retention than did the parallel posts. Scanning electron microscropic analysis indicated that more cement adhered to the surfaces of the parallel fiberglass post than to those of the tapered fiberglass post. All posts demonstrated some plastic behavior, with the double-tapered fiber quartz post being stiffer than the others. CONCLUSION: Parallel fiber-reinforced composite posts showed better retention than did tapered posts when a dual-cured resin-based cement was used. Translucent prefabricated posts have limited light transmission. CLINICAL IMPLICATIONS: Parallel prefabricated fiber posts luted with dual-cured resin-based cement seem to be suitable for clinical application in endodontically treated teeth that require post-and-core restoration, showing good retention and acceptable fracture resistance.

PMID: 16803828 [PubMed - indexed for MEDLINE]

A retrospective clinical evaluation of two-unit cantilevered resin-bonded fixed partial dentures.

J Am Dent Assoc. 2006 Jun;137(6):783-8

Authors: Botelho MG, Leung KC, Ng H, Chan K

BACKGROUND: The authors conducted a study to examine the clinical performance of two-unit cantilevered resin-bonded fixed partial dentures (RBFPDs) that were inserted at The Prince Philip Dental Hospital, University of Hong Kong. METHODS: The authors recalled patients who had received two-unit cantilevered RBFPDs at least 24 months before the recall examination. The authors recorded the following data: patient's sex and age, operator's experience, prosthesis cementation date, endodontic treatment if performed, bone support, tooth mobility, the presence of shim-stock contacts on the abutment or pontic in intercuspal position, and the presence of aproximal axial contacts adjacent to the prosthesis. They also recorded the date of any debonding with subsequent treatment. They asked the patients qualitative questions about their prostheses. RESULTS: A total of 269 prostheses were placed in 214 patients and had a mean service life of 51.7 months +/- 19.5 months standard deviation, with a range of 13.2 to 141.6 months. Of 14 failed prostheses, 12 debonded, resulting in a success rate of 94.8 percent and clinical retention rate of 95.5 percent. No discernable rotation or drifting of the abutments was apparent in any of the prostheses. Overall patient satisfaction with RBFPDs was good, with an average assessment score of 8.5. CONCLUSIONS: The authors observed a 95.5 percent clinical retention rate of 269 two-unit RBFPDs, with no apparent drifting of the abutments. Longer-term follow-up studies are required. CLINICAL IMPLICATIONS: Two-unit RBFPDs are conservative and clinically retentive prostheses in the short to medium term.

PMID: 16803807 [PubMed - indexed for MEDLINE]

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]

Facing the challenges of ceramic veneers.

J Am Dent Assoc. 2006 May;137(5):661-4

Authors: Christensen GJ

Ceramic veneers are extremely popular and have been used for many years. In spite of their phenomenal success, they offer numerous challenges during service. In this column, I have identified and discussed several degenerative situations commonly observed, and I have described methods of preventing or reducing the problems. When properly placed, ceramic veneers are among the most beautiful and long-lasting of all dental restorations.

PMID: 16739547 [PubMed - indexed for MEDLINE]

Fracture resistance of different partial-coverage ceramic molar restorations: An in vitro investigation.

J Am Dent Assoc. 2006 Apr;137(4):514-22

Authors: Stappert CF, Att W, Gerds T, Strub JR

BACKGROUND: The authors conducted a study to evaluate the influence of preparation design on reliability and fracture resistance of press-ceramic posterior partial-coverage restorations (PCRs) under fatigue. They compared the results for PCRs fabricated of a new press ceramic (IPS e.max Press-VP 1989/4, Ivoclar-Vivadent, Schaan, Liechtenstein) with results for ceramic inlays and unprepared molars. METHODS: The authors randomly divided 96 human upper molars into six equal groups. Control group NP specimens remained unprepared. Control group IN specimens received a mesio-occlusal-distal (MOD) inlay preparation. The test groups received PCR preparation designs based on group IN's inlay design, with additional cuspal reduction that increased from group to group. The authors fabricated 16 ceramic inlays and 64 PCRs of IPS e.max Press and luted them adhesively. All specimens underwent masticatory fatigue loading (1.2 million cycles, 1.6 hertz, 98 newtons), 5,300 thermal cycles and observation for fracture patterns. Afterward, the authors loaded all surviving specimens until fracture. RESULTS: No fractures occurred during the exposure to the masticatory simulation. After undergoing loading in a universal testing machine, the groups showed no significant differences in fracture strength values (P = .6026). Thus, the different preparation designs of the PCRs demonstrated no significant influence on the restorations' fracture resistance. The median failure loads ranged from 1,567 to 1,960 newtons. CONCLUSION: All-ceramic PCRs for molars made of IPS e.max Press were shown to be fracture-resistant, results comparable with those of natural unprepared teeth. CLINICAL IMPLICATIONS: When a posterior ceramic PCR is indicated, the clinician should perform a defect-oriented preparation that preserves tooth structure. Further clinical investigations are recommended to verify the authors' in vitro results.

PMID: 16637481 [PubMed - indexed for MEDLINE]

Development of a self-etch adhesive for resin-modified glass ionomers.

J Dent Res. 2006 Apr;85(4):349-53

Authors: Coutinho E, Van Landuyt K, De Munck J, Poitevin A, Yoshida Y, Inoue S, Peumans M, Suzuki K, Lambrechts P, Van Meerbeek B

The favorable self-adhesiveness of resin-modified glass ionomers (RMGIs) might be even further improved if the time-consuming and technically sensitive etch-and-rinse pre-treatment step with polyalkenoic acids could be avoided. We undertook this study to assess the effectiveness of an experimental self-etch adhesive for RMGIs that does not need to be rinsed off. Ultrastructural analysis and micro-tensile bond strength testing to enamel and dentin of a RMGI restorative material and a RMGI adhesive were performed after 4 different surface pre-treatments: no conditioning; 25% polyalkenoic acid; an experimental self-etch adhesive; and 37.5% phosphoric acid followed by the experimental self-etch adhesive. The use of an experimental self-etch adhesive increased the bond strength of RMGIs, especially after an additional conditioning step. Interfacial analysis showed the formation of a thin hydroxyapatite-containing hybrid layer. The self-etch technique enhances the user-friendliness of RMGIs and lowers their technique-sensitivity, while maintaining desirable characteristics of the conventional etch-and-rinse approach with polyalkenoic acids.

PMID: 16567557 [PubMed - indexed for MEDLINE]

Fracture surface analysis of clinically failed fixed partial dentures.

J Dent Res. 2006 Mar;85(3):277-81

Authors: Taskonak B, Mecholsky JJ, Anusavice KJ

Ceramic systems have limited long-term fracture resistance, especially when they are used in posterior areas or for fixed partial dentures. The objective of this study was to determine the site of crack initiation and the causes of fracture of clinically failed ceramic fixed partial dentures. Six Empress 2 lithia-disilicate (Li(2)O x 2SiO(2))-based veneered bridges and 7 experimental lithia-disilicate-based non-veneered ceramic bridges were retrieved and analyzed. Fractography and fracture mechanics methods were used to estimate the stresses at failure in 6 bridges (50%) whose fracture initiated from the occlusal surface of the connectors. Fracture of 1 non-veneered bridge (8%) initiated within the gingival surface of the connector. Three veneered bridges fractured within the veneer layers. Failure stresses of the all-core fixed partial dentures ranged from 107 to 161 MPa. Failure stresses of the veneered fixed partial dentures ranged from 19 to 68 MPa. We conclude that fracture initiation sites are controlled primarily by contact damage.

PMID: 16498078 [PubMed - indexed for MEDLINE]

A one-year clinical evaluation of a high-viscosity glass ionomer cement in primary molars.

J Contemp Dent Pract. 2006 Feb 15;7(1):71-8

Authors: Yilmaz Y, Eyuboglu O, Kocogullari ME, Belduz N

In this study one-year clinical results of high-viscosity glass ionomer cement (GIC) (Fuji IX, A3, GC, Japan) were determined in class I and class II restorations in 68 primary molars with occlusal or approximal caries. Following caries removal and cavity preparation, the teeth were restored with Fuji IX. The restorations were evaluated according to the U.S. Public Health Service's (USPHS) criteria at the end of one year. Statistical analyses of the data obtained were analyzed using the X2 test. The evaluations showed no statistically significant difference between class I and class II restorations in terms of the color mismatch, anatomic form, marginal adaptation, and secondary caries (P>0.05), but they were statistically significant with regard to cavosurface marginal discoloration (P<0.05). At the end of one year, the success rate of the class I and class II restorations of the primary molars restored with Fuji IX was 94%.

PMID: 16491149 [PubMed - indexed for MEDLINE]

Outcome of endodontic treatment of teeth filled using lateral condensation versus vertical compaction (Schilder's technique).

J Contemp Dent Pract. 2006 Feb 15;7(1):17-24

Authors: Aqrabawi JA

The purpose of this prospective clinical and radiographic investigation was to assess the treatment results following endodontic therapy of teeth filled with lateral condensation versus teeth filled with vertical compaction of warm gutta-percha. A total of 290 patients were treated using the standardized step-back technique for canal preparation, which were filled with either lateral condensation or vertical compaction in one single session. Five years later, the treatment results were assessed clinically and radiographically and related to the type of the obturation technique using Chi-square analysis. Of the 340 teeth that were reexamined, 160 teeth were filled with lateral condensation, and 180 teeth were filled with vertical condensation. The results showed a significantly higher success rate for the vertical compaction versus the lateral condensation technique of teeth presented with preoperative periapical lesions P<0.04. Regardless of the preoperative periapical status of the teeth, no statistically significant difference was found between the two techniques. The overall success rate of both filling techniques was 80.3%.

PMID: 16491144 [PubMed - indexed for MEDLINE]

Retrospective clinical and radiologic evaluation of nonsurgical endodontic treatment in human immunodeficiency virus (HIV) infection.

J Contemp Dent Pract. 2006 Feb 15;7(1):1-8

Authors: Suchina JA, Levine D, Flaitz CM, Nichols CM, Hicks MJ

PURPOSE: This retrospective study evaluated the clinical and radiographic status of nonsurgical endodontic treatment (ET) of anterior and posterior teeth in HIV-seropositive patients. METHODS: ET was analyzed in 26 anterior and 34 posterior teeth from 54 consecutive HIV patients (gender ratio 3 Male : 1 Female, mean age 40.2 years, mean CD4 240, CD4<500 in 88%, 12 with AIDS) over a six year period with a minimum of six months follow-up. ET was evaluated as successful, questionable, or failure based upon clinical factors (palpation, mobility, sinus tract, percussion, function, infection/swelling, occlusion, symptoms) and radiographic factors (periodontal ligament space, rarefaction, lamina dura, root resorption, obturation) during post-treatment examinations with a mean follow up of 26 months. RESULTS: Clinical evaluation at follow up found ET outcome was successful in 88%, questionable in 10% (tenderness with percussion, mobility, widened ligament), and a failure in 2% (developed lesion after ET). Periapical lesions were present in 37% of cases (mean lesion size 6.2 mm). Following ET, mean lesion size (1.8 mm) had decreased by 71%. Obturation was evaluated as optimal or acceptable in 68%. Radiographic evaluation was considered successful in 80%, no change in 15%, and a failure in 5%. CONCLUSIONS: Despite obturation deficiencies and the immunocompromised state of the patients, endodontic therapy has a relatively high degree of success in the majority of HIV/AIDS patients. HIV infection and AIDS should not be considered as a contraindication to endodontic therapy in this patient population.

PMID: 16491142 [PubMed - indexed for MEDLINE]

The clinical performance of CAD/CAM-generated composite inlays.

J Am Dent Assoc. 2005 Dec;136(12):1714-23

Authors: Fasbinder DJ, Dennison JB, Heys DR, Lampe K

BACKGROUND: The authors conducted a study to evaluate the longitudinal clinical performance of a resin-based composite (Paradigm, 3M ESPE, St. Paul, Minn.) for computer-aided design/computer-aided manufacturing (CAD/CAM)-generated adhesive inlays. METHODS: The researchers used a CAD/CAM unit (CEREC 2, Sirona Dental Systems, Bensheim Germany) to fabricate 40 porcelain (Vita Mark II, Vita Zahnfabrik, Bad S&#xE4;ckingen, Germany) and 40 resin-based composite (Paradigm, 3M ESPE) inlays. Both restorative materials were cemented with a total-etch technique using Single Bond dental adhesive (3M ESPE) and a dual-cured resin cement (RelyX ARC Adhesive Resin Cement, 3M ESPE). Two examiners evaluated the inlays using modified U.S. Public Health Service (PHS) criteria at six months, one year, two years and three years. RESULTS: No sensitivity was reported for either material at any recall period. There was no significant difference between the two materials relative to margin adaptation at three years. Margin adaptation initially was very good for both materials, with an increase in margin detection due to apparent wear of the resin-based composite luting agent. There was a significant difference in color match between the two materials at three years, with 91.4 percent of the resin-based composite inlays and 58.8 percent of the porcelain inlays rated Alfa. CONCLUSIONS AND CLINICAL IMPLICATIONS: The resin-based composite inlays had a significantly better color match at three years than did the porcelain inlays. Resin-based composite CAD/CAM inlays performed as well as porcelain CAD/CAM inlays after three years of clinical service.

PMID: 16383055 [PubMed - indexed for MEDLINE]

Clinical evaluation of packable and conventional hybrid posterior resin-based composites: results at 3.5 years.

J Am Dent Assoc. 2005 Nov;136(11):1533-40

Authors: Poon EC, Smales RJ, Yip KH

BACKGROUND: The authors evaluated clinical performances of a packable and a conventional hybrid resin-based composite used with a self-etch adhesive system. METHODS: Three dentists placed 105 posterior restorations in 65 adults. They placed a packable (SureFil, Dentsply DeTrey GmbH, Konstanz, Germany) and a conventional (Spectrum, Dentsply DeTrey GmbH) resin-based composite using a self-etch resin adhesive system. The authors evaluated the restorations using Ryge modified criteria, photographs and die stone replicas. RESULTS: After 3.5 years, six large SureFil and two Spectrum restorations had failed from bulk fracture and secondary caries, resulting in cumulative survival rates of 81.3 and 92.0 percent, respectively. Failed SureFil restorations generally were larger than the remaining intact restorations. Other ratings were satisfactory, with no significant differences between the two materials for any restoration parameter. Alfa ratings for both materials were approximately 80 percent or greater for marginal discoloration, anatomical form, surface texture and surface staining. Lower percentages of restorations were rated Alfa for color match, marginal integrity and gingival health. No postoperative sensitivity was reported. Net mean occlusal wear (+/- standard deviation) was 28.9 (+/- 32.9) micrometers for SureFil and 33.8 (+/- 29.6) microm for Spectrum restorations; the difference was not statistically significant. CONCLUSIONS: When used with a self-etch adhesive, the 3.5-year clinical performances of both composites were similar and satisfactory for the restoration of Class I and moderate-sized Class II cavities. Clinical Implications. The two composites placed in this study have an increased risk of bulk fracture when placed in large intracoronal Class II molar preparations.

PMID: 16329416 [PubMed - indexed for MEDLINE]

Failures related to crowns and fixed partial dentures fabricated in a Nigerian dental school.

J Contemp Dent Pract. 2005 Nov 15;6(4):136-43

Authors: Oginni AO

The purpose of this investigation was to document the failure rate and length of service of crowns and fixed partial dentures (FPDs) fabricated in a Nigerian dental school. The reasons for failure of the initial restorations and their length of service were also ascertained. Also, the numbers of retainers, pontics, and the types of restoration were recorded. Poor esthetics was the most frequent cause of failure, 66 units (40.5%); followed by fracture, 58 units (35.6%); and dental caries, 25 units (15.4%). These outcomes were contrary to findings previously reported in studies from western countries where dental caries was principally responsible for failures (22.0% to 38.0% of cases). The resin-retained FPDs had the shortest mean years of service at 2.7 years, while the three-unit metal-ceramic FPDs had the greatest longevity at 8.6 years. The overall mean years of service for replaced restorations were 5.6 years. The study found a decrease in the mean years of service as the number of units in the fixed-fixed partial dentures increased. This is in sharp contrast to previous reports where no relationship existed between length of service and the number of units in a FPD.

PMID: 16299615 [PubMed - indexed for MEDLINE]

Evaluation of endodontic treatments performed by students in a Brazilian Dental School.

J Dent Educ. 2005 Oct;69(10):1161-70

Authors: De Quadros I, Gomes BP, Zaia AA, Ferraz CC, Souza-Filho FJ

The aims of this study were to evaluate the clinical outcomes of root canal treatments performed by final-year students in the Dental School of Piracicaba, State University of Campinas, SP, Brazil, during the year 2000 and to evaluate the success rate of these treatments at follow-ups conducted one and three years later (2001-03). All 579 endodontic treatments performed by final-year students were selected for this investigation. Detailed personal and dental history was obtained from the patient's records. Clinical and radiographic follow-up examinations were performed. For 78.8 percent of the cases, dental caries was recorded as the cause for performing endodontic treatment; for 8.8 percent, prosthetic reasons were given; and for 12.4 percent, failure of the endodontic treatment was the reason. The largest percentage (30.7 percent) of recalled patients was examined after one year; the success rate at this follow-up evaluation ranged from 83 percent to 96 percent depending on the pulp status prior to the root canal treatment. After three years, only 8 percent of treated patients returned; assessment for them revealed a 75.5 percent success rate. Dental caries is still the main reason for endodontic treatment. This level of success of the root canal treatment in a Brazilian dental school is similar to other reports in the literature.

PMID: 16204682 [PubMed - indexed for MEDLINE]

Tubular occlusion prevents water-treeing and through-and-through fluid movement in a single-bottle, one-step self-etch adhesive model.

J Dent Res. 2005 Oct;84(10):891-6

Authors: Tay FR, Pashley DH, Hiraishi N, Imazato S, Rueggeberg FA, Salz U, Zimmermann J, King NM

Water entrapment occurs at resin-dentin interfaces of one-step self-etch adhesives. We hypothesized that by preventing water fluxes from dentin, any water entrapment would be attributed to incomplete removal of adhesive solvents. We tested this hypothesis by bonding to transparent carious dentin containing occluded dentinal tubules. An experimental single-bottle, one-step self-etch adhesive was applied to flat surfaces of caries-affected dentin surrounded by sound dentin, with or without pulpal pressure. Resin-dentin interfaces were examined with TEM after silver-impregnation. Although caries-affected dentin was highly porous, adhesive layers were devoid of silver deposits when tubules were occluded. Conversely, variable extents of water-treeing and water-droplets were identified from adhesive layers in bonded sound dentin. Water-treeing and water-droplet formation, being manifestations of evaporative and convective water fluxes, can be eliminated during bonding to occluded transparent carious dentin. However, the highly porous nature of this clinically relevant substrate after bonding may lead to potentially undesirable consequences.

PMID: 16183786 [PubMed - indexed for MEDLINE]

Clinical and radiographic behaviour of 290 dental implants with a surface treated with hydrofluoric acid and passivated with hydrofluoric and nitric acid: early loading results after 2 years.

Med Oral Patol Oral Cir Bucal. 2005 Aug-Oct;10(4):355-61

Authors: Mart&#xED;nez-González JM, Barona-Dorado C, Cano-Sánchez J, Flórez-Rodríguez M, Cantero-Alvarez M

OBJECTIVE: This work presents the results of clinical and radiological behaviour, for 2 years, of 290 implants treated with a first etching with HF and a second etching with HF and HNO3 acids and that were loaded 8 weeks after insertion. EXPERIMENTAL DESIGN: It is a prospective study on 290 implants placed in 56 patients with an age range from 28 to 81. The selection was previously made through radiological study with panoramic and tomographic radiographs, followed by the implantological treatment with prosthetic loading and clinical (15 days, 1, 3 , 6, 12, 18 and 24 months) and radiological control (12 and 24 months). RESULTS: During the healing period, 11 implants failed, resulting in a CSR of 96.21%. After prostheses placement at 2 months, 4 implants were retired, successfully remaining 275 implants. CONCLUSIONS: The following and favourable results after the prosthetic loading of 179 implants (CSR of 98.56%), attest that early loading may and must be applied, after rigorous planning and case selection.

PMID: 16056190 [PubMed - indexed for MEDLINE]

Preprosthetic and implantological surgery in patients with severe maxillary atrophy.

Med Oral Patol Oral Cir Bucal. 2005 Aug-Oct;10(4):343-54

Authors: González-García R, Naval-Gías L, Muñoz-Guerra MF, Sastre-Pérez J, Rodríguez-Campo FJ, Gil-Díez-Usandizaga JL

AIMS: To evaluate the success of the osseointegration of dental implants in patients with severe maxillary atrophy after sinus lift augmentation and onlay graft surgery with autologous bone grafts. DESIGN: A descriptive and analytic study of 27 patients with severe maxillary atrophy and partial or total edentulism, after 4 years follow-up. All cases underwent to autologous bone graft sinus lift augmentation with or without onlay grafts in the anterior maxillae. After this, reconstruction with osseointegrated implants was performed. RESULTS: After the follow-up period, 89.1% of implants were osseointegrated and loaded. Anterior iliac crest bone graft provides good results with respect to implant osseointegration. The achievement of two surgical procedures for bone grafts surgery and implants surgery, separated 2 or more months, provides better results for osseointegration in comparison to a sole surgical procedure (p<0.01). CONCLUSIONS: Implants survival predictability is greater when a second surgical procedure is performed, once bone grafts have experimented an appropriate consolidation. The use of onlay graft and sinus lift augmentation techniques is useful in the resolution of complex problems such as the severe maxillary atrophy.

PMID: 16056189 [PubMed - indexed for MEDLINE]

The clinical performance of one- and two-step self-etching adhesive systems at one year.

J Am Dent Assoc. 2005 May;136(5):656-64; quiz 683

Authors: Türkün LS

BACKGROUND: The author compared the clinical performance of a two-step self-etching adhesive system and a one-step self-etching adhesive system over one year. METHODS: Thirty-five patients with noncarious cervical lesions were enrolled in the study. The author restored 163 lesions using a two-step (Clearfil Protect Bond, Kuraray, Osaka, Japan) or a one-step (Xeno III, Dentsply/DeTrey, Konstanz, Germany) self-etching adhesive system. Enamel margins were not beveled, and no mechanical retentions were placed. The author evaluted the restorations at baseline and at three, six, nine and 12 months after placement using modified Ryge criteria for color-matching ability, marginal discoloration, marginal adaptation, initial caries formation, anatomical form, postoperative sensitivity and retention loss. RESULTS: The author assessed the changes in the parameters using the Cochran Q test and the McNemar test at a significance level of .05. At one year, the retention rates for the restorations in the two-step group were 100 percent; they were 96 percent for the restorations in the one-step group. Of the retained 75 restorations from the one-step group, two had marginal discoloration and slight anatomical form problems. In both groups, color-matching ability and postoperative sensitivity remained excellent. CONCLUSION: The performance of both self-etching adhesive systems was excellent during this one-year clinical trial. However, the two-step system exhibited slightly better retention than the one-step system. CLINICAL IMPLICATIONS: The one- and two-step self-etching adhesive systems evaluated in this study provided excellent clinical retention in noncarious lesions without mechanical retention.

PMID: 15966655 [PubMed - indexed for MEDLINE]

The clinical significance and management of apical accessory canals in maxillary central incisors.

J Am Dent Assoc. 2005 Mar;136(3):331-5; quiz 379-81

Authors: Iqbal MK, Gartenberg J, Kratchman SI, Karabucak B, Bui B

BACKGROUND: The maxillary central incisor is considered to be the least difficult subject for a clinical endodontic experience. However, the internal anatomy of maxillary central incisors can present a number of variations, including multiple accessory canals. CASE DESCRIPTION: This article highlights the clinical significance and management of accessory canals located in the apical one-third of maxillary central incisors. The authors present two case reports in which failure to detect the accessory canals led to root canal failure and subsequent surgical intervention. Another two case reports present the serendipitous discovery and nonsurgical management of accessory canals during the initial treatment of maxillary incisors. CONCLUSIONS AND CLINICAL IMPLICATIONS: It is important for the clinician to be able to detect the signs suggesting the presence of accessory canals in maxillary central incisors. Failure to do so may lead to a less-than-optimal endodontic treatment outcome.

PMID: 15819346 [PubMed - indexed for MEDLINE]

A three-year clinical evaluation of two-bottle versus one-bottle dentin adhesives.

J Am Dent Assoc. 2005 Mar;136(3):311-22

Authors: Aw TC, Lepe X, Johnson GH, Mancl LA

BACKGROUND: The authors conducted an in vivo investigation to compare the clinical performance of two commercial one-bottle adhesives and a two-bottle adhesive for restoration of noncarious cervical lesions (NCCLs). METHOD: The patient pool consisted of 57 patients and 171 teeth (three teeth per patient), with one NCCL per tooth. Each patient received three resin-based composite restorations, each with a different adhesive: one tooth with a two-bottle, water-based adhesive as the control; another tooth with a one-bottle, ethanol-based adhesive; and a third tooth with a one-bottle, solvent-free adhesive. The authors assessed restorations in terms of retention, marginal integrity, margin discoloration and air sensitivity at baseline, six months, one year, two years and three years after initial placement. RESULTS: The retention rates at 36 months were 88 percent for the first adhesive, 81 percent for the second adhesive and 90 percent for the third adhesive. No statistically significant differences in retention rates could be shown, with 86 percent of restorations retained overall. Measures of marginal integrity, marginal discoloration and sensitivity also had no statistically significant differences between the three adhesives (P > .05). CONCLUSIONS: All three adhesives performed with acceptable outcomes after a 36-month period, with small differences between the one- and two-bottle systems and between the various solvents. Retention rate was moderately high and air sensitivity was markedly reduced; however, superficial marginal discoloration and marginal degradation was notable. Certain lesion, tooth and patient characteristics may predispose restorations to retention failure. CLINICAL IMPLICATIONS: The type of solvent may not be a major factor in retention of Class V restorations in NCCLs. Both single-bottle adhesives and conventional two-bottle adhesives performed acceptably.

PMID: 15819344 [PubMed - indexed for MEDLINE]

Periapical surgery using the ultrasound technique and silver amalgam retrograde filling. A study of 71 teeth with 100 canals.

Med Oral Patol Oral Cir Bucal. 2005;10 Suppl 1:E67-73

Authors: Mart&#xED;-Bowen E, Peñarrocha-Diago M, García-Mira B

INTRODUCTION: Periapical surgery using ultrasound allows the treatment of root canals of difficult access, with the sacrifice of little root tissue. As a result, periapical disorders which were condemned to treatment failure in the past can now be dealt with successfully. MATERIAL AND METHODS: In 71 teeth presenting 100 root canals treated with ultrasound and subjected to retrograde filling with silver amalgam, the course and short-term success of management was evaluated in relation to lesion size, the magnitude of apical resection, and the size of the retrograde filling cavity. The duration of follow-up was one year, with post-treatment controls after 6 and 12 months. RESULTS: After 6 months, the percentage clinical and radiological success was 92% and 58%, respectively. One year after periapical surgery the corresponding percentages were 95% and 80%. Global success after 6 months was 63%, versus 84.2% after 12 months. No statistically significant relation was observed between treatment success and the size of the periapical lesion, the amount of apex resected, or the size of retrograde filling. CONCLUSION: Periapical surgery using ultrasound and retrograde filling with silver amalgam affords a high success rate after 12 months.

PMID: 15800469 [PubMed - indexed for MEDLINE]

Implant rehabilitation of the atrophic upper jaw: a review of the literature since 1999.

Med Oral Patol Oral Cir Bucal. 2005;10 Suppl 1:E45-56

Authors: Sorn&#xED; M, Guarinós J, García O, Peñarrocha M

The severely resorbed maxilla presents serious limitations for conventional implant placement. As a result, different techniques have been developed in the last two decades, with variable results. The most significant approaches comprise the placement of implants in anatomical abutments, elevation of the sinus floor, and reconstructive surgery with bone grafting. The present study reviews the most important articles on the management of the atrophic upper jaw published in the literature since 1999.

PMID: 15800467 [PubMed - indexed for MEDLINE]

Single-unit implants versus conventional treatments for compromised teeth: a brief review of the evidence.

J Dent Educ. 2005 Apr;69(4):414-8

Authors: Tang CS, Naylor AE

The goal of preserving the natural dentition has long provided the foundation for clinical decision making in dentistry. Current trends in implant dentistry have weakened this paradigm as many practitioners have moved quickly to adopt implant dentistry as a new standard of care; however, the rapidity of this shift is a cause for concern among others. Many short-term studies have reported favorable data supporting the growth of single-unit implant dentistry, but the lack of standardized outcome evaluations and broadly conceived dimensions of performance makes it difficult to compare these reports. Thus, even with the exciting new treatment options implant dentistry offers patients and practitioners, all due consideration should first be given to treatments aimed at preserving and restoring compromised teeth before pursuing extraction and replacement. This article examines this premise from five perspectives: form, function, survival, management of complications, and quality of life.

PMID: 15800254 [PubMed - indexed for MEDLINE]

Longevity of posterior tooth dental restorations.

J Am Dent Assoc. 2005 Feb;136(2):201-3

Authors: Christensen GJ

Several forms of restorative techniques are used for posterior teeth. They vary significantly in cost and longevity. The following restorative concepts are the most commonly used: amalgam, resin-based composite, PFM, cast gold alloy restorations and all-ceramic restorations. I suggest that patients be informed about the potential longevity of restorative treatment for posterior teeth as they make decisions about treatment for their oral restorative needs.

PMID: 15782524 [PubMed - indexed for MEDLINE]

Do procedural errors cause endodontic treatment failure?

J Am Dent Assoc. 2005 Feb;136(2):187-93; quiz 231

Authors: Lin LM, Rosenberg PA, Lin J

BACKGROUND: This article reviews the effect of endodontic procedural errors, such as underfilling, overfilling, root perforations and separated instruments, on the outcome of endodontic therapy. TYPES OF STUDIES REVIEWED: Filling the root canal more than 2 millimeters from the radiographic apex (underfilling) or beyond the radiographic apex (overfilling), perforations of the root canal system and instrument separation are possible complications of endodontic therapy. Although these procedural errors may have different causes, they all may affect the outcome of treatment. RESULTS: Endodontic procedural errors are not the direct cause of treatment failure; rather, the presence of pathogens in the incompletely treated or untreated root canal system is the primary cause of periradicular pathosis. Procedural errors typically are due to several factors. Among them is a lack of understanding of the root canal anatomy, the principles of mechanical instrumentation and tissue wound healing. CLINICAL IMPLICATIONS: Procedural errors impede endodontic therapy, thus increasing the risk of treatment failure, especially in teeth with necrotic pulps and periradicular lesions. However, procedural errors often are preventable.

PMID: 15782522 [PubMed - indexed for MEDLINE]

Dental sealant longevity in a cohort of young U.S. naval personnel.

J Am Dent Assoc. 2005 Feb;136(2):171-8; quiz 230

Authors: Simecek JW, Diefenderfer KE, Ahlf RL, Ragain JC

BACKGROUND: The U.S. Navy emphasizes caries prevention and encourages the placement of dental sealants on the caries-susceptible teeth of patients at risk of developing caries. The authors analyzed dental records to assess the longevity of dental sealants placed in naval personnel. METHODS: A cluster sample of dental records from 1,123 personnel who entered naval service in 1997 was drawn from eight Navy dental treatment facilities. The authors determined the number of sealants provided, the number of sealants that failed over the observation period (1997-2001), the dates of sealant failure and the longevity of sealants placed during and after recruit training. RESULTS: A total of 319 personnel received sealants during their first two years of service. The authors evaluated 1,467 sealed teeth. They followed the sealants for an average of 35 months. They noted 179 sealant failures in 102 subjects; 69 previously sealed teeth required sealant replacement, and 110 sealed teeth required restoration of the occlusal surface. Among those sealants that failed, the mean length of time from placement to failure was 26 months. Sealant failure rates were significantly higher among subjects at moderate risk or high risk of developing caries than among subjects at low risk. CONCLUSIONS: After an average of 35 months, 87.8 percent of the sealants placed in this population were retained and functional. Subjects who were at moderate or high risk of developing caries demonstrated significantly higher sealant failure rates than those at low risk of developing caries. CLINICAL IMPLICATIONS: Dental sealants can be retained successfully in adults. They should be considered a viable treatment alternative for adult patients who are susceptible to caries; however, patients at elevated risk of developing caries may require more frequent re-evaluation and maintenance to achieve maximum benefit.

PMID: 15782520 [PubMed - indexed for MEDLINE]

A critical review of the durability of adhesion to tooth tissue: methods and results.

J Dent Res. 2005 Feb;84(2):118-32

Authors: De Munck J, Van Landuyt K, Peumans M, Poitevin A, Lambrechts P, Braem M, Van Meerbeek B

The immediate bonding effectiveness of contemporary adhesives is quite favorable, regardless of the approach used. In the long term, the bonding effectiveness of some adhesives drops dramatically, whereas the bond strengths of other adhesives are more stable. This review examines the fundamental processes that cause the adhesion of biomaterials to enamel and dentin to degrade with time. Non-carious class V clinical trials remain the ultimate test method for the assessment of bonding effectiveness, but in addition to being high-cost, they are time- and labor-consuming, and they provide little information on the true cause of clinical failure. Therefore, several laboratory protocols were developed to predict bond durability. This paper critically appraises methodologies that focus on chemical degradation patterns of hydrolysis and elution of interface components, as well as mechanically oriented test set-ups, such as fatigue and fracture toughness measurements. A correlation of in vitro and in vivo data revealed that, currently, the most validated method to assess adhesion durability involves aging of micro-specimens of biomaterials bonded to either enamel or dentin. After about 3 months, all classes of adhesives exhibited mechanical and morphological evidence of degradation that resembles in vivo aging effects. A comparison of contemporary adhesives revealed that the three-step etch-and-rinse adhesives remain the 'gold standard' in terms of durability. Any kind of simplification in the clinical application procedure results in loss of bonding effectiveness. Only the two-step self-etch adhesives approach the gold standard and do have some additional clinical benefits.

PMID: 15668328 [PubMed - indexed for MEDLINE]

Frailty approach for the analysis of clustered failure time observations in dental research.

J Dent Res. 2005 Jan;84(1):54-8

Authors: Chuang SK, Cai T, Douglass CW, Wei LJ, Dodson TB

Because dental implant failure patterns tend to cluster within subjects, we hypothesized that the risk of implant failure varies among subjects. To address this hypothesis in the setting of clustered, correlated observations, we considered a retrospective cohort study where we identified a cohort having at least one implant placed. The cohort was composed of 677 patients who had 2349 implants placed. To test the hypothesis, we applied an innovative analytic method, i.e., the Cox proportional hazards model with frailty, to account for correlation within subjects and the heterogeneity of risk, i.e., frailty, among subjects for implant failure. Consistent with our hypothesis, risk for implant failure among subjects varied to a statistically significantly degree (p=0.041). In addition, the risk for implant failure is significantly associated with several factors, including tobacco use, implant length, immediate implant placement, staging, well size, and proximity of adjacent implants or teeth.

PMID: 15615876 [PubMed - indexed for MEDLINE]

Periimplantitis.

Med Oral Patol Oral Cir Bucal. 2004;9 Suppl:69-74; 63-9

Authors: S&#xE1;nchez-Gárces MA, Gay-Escoda C

Orodental rehabilitation through the use of implants offers very high success rates. In this paper, we describe some of the complications involved with this technique, such as periimplant disease and, within this category, periimplantitis, an inflammatory reaction in which there is a loss of the bony support of the implant accompanied by inflammation. The aetiology of the disease is conditioned by the status of the tissue surrounding the implant, implant design, degree of roughness, the poor alignment of implant components, external morphology and excessive mechanical load. The microorganisms most commonly associated with implant failure are spirochetes and mobile forms of Gram-negative anaerobes, unless the origin is the result of simple mechanical overload. Diagnosis is based on changes of colour in the gum, bleeding and probing depth of periimplant pockets, suppuration, x-ray and gradual loss of bone height around the tooth. Treatment will differ depending upon whether it is a case of mucositis or periimplantitis. Therapeutic objectives focus on correcting technical defects by means of surgery and decontamination techniques (abrasion with carbon particles, citric acid solution, topical tetracycline application and laser surgery). This study also presents a microbiological study of periimplantitis conducted by the Barcelona School of Dentistry that determined that the antibiotic therapy proven to be most efficacious in the antibiogram was the association of amoxycillin and clavulanic acid.

PMID: 15580138 [PubMed - indexed for MEDLINE]

Pathogenesis of apical periodontitis and the causes of endodontic failures.

Crit Rev Oral Biol Med. 2004;15(6):348-81

Authors: Nair PN

Apical periodontitis is a sequel to endodontic infection and manifests itself as the host defense response to microbial challenge emanating from the root canal system. It is viewed as a dynamic encounter between microbial factors and host defenses at the interface between infected radicular pulp and periodontal ligament that results in local inflammation, resorption of hard tissues, destruction of other periapical tissues, and eventual formation of various histopathological categories of apical periodontitis, commonly referred to as periapical lesions. The treatment of apical periodontitis, as a disease of root canal infection, consists of eradicating microbes or substantially reducing the microbial load from the root canal and preventing re-infection by orthograde root filling. The treatment has a remarkably high degree of success. Nevertheless, endodontic treatment can fail. Most failures occur when treatment procedures, mostly of a technical nature, have not reached a satisfactory standard for the control and elimination of infection. Even when the highest standards and the most careful procedures are followed, failures still occur. This is because there are root canal regions that cannot be cleaned and obturated with existing equipments, materials, and techniques, and thus, infection can persist. In very rare cases, there are also factors located within the inflamed periapical tissue that can interfere with post-treatment healing of the lesion. The data on the biological causes of endodontic failures are recent and scattered in various journals. This communication is meant to provide a comprehensive overview of the etio-pathogenesis of apical periodontitis and the causes of failed endodontic treatments that can be visualized in radiographs as asymptomatic post-treatment periapical radiolucencies.

PMID: 15574679 [PubMed - indexed for MEDLINE]

Influence of Different Techniques of Laboratory Construction on the Fracture Resistance of Fiber-Reinforced Composite (FRC) Bridges.

J Contemp Dent Pract. 2004 Nov 15;5(4):1-13

Authors: Ellakwa AE, Shortall AC, Marquis PM

The aim of the current investigation is to evaluate optimal pontic and retainer fiber positions for Polyethylene fiber-reinforced composite (FRC) restorations. In series I notch disc specimens were used to mimic loading cuspal regions of pontics. Four groups (n=15/group; codes A to D) were prepared from Artglass composite. Groups A to C were reinforced with polyethylene fibers, and group D was an unreinforced control. Fibers were positioned either around (A), beneath the notch (B), or at the disc base (C). Specimens were stored in distilled water at 37 degrees C for 24 h before testing to failure (CHS=1mm/min) in a universal testing machine. Mean torque to failure values ranked [P< 0.05; one-way analysis of variance (ANOVA)] as follows A = B > C = D. In series II five groups of three unit bridges (n =5/group; codes A to E) were prepared from Artglass dental composite without (group A) or with (groups B to E) different Connect fiber reinforcement locations/techniques. Bridges were cemented using 2 bond resin cement to a standardized substructure. After storage, as per series I, bridges were loaded mid-pontic region to failure. One-way ANOVA showed no significant (P=0.08) difference between test groups. The research hypothesis was that notched disc and 3 unit bridge test techniques would discriminate equally between fiber-reinforced specimens and an unreinforced composite control was rejected.

PMID: 15558085 [PubMed - indexed for MEDLINE]

Clinical/photographic evaluation of a single application of two sealants after eleven years.

Bull Tokyo Dent Coll. 2004 May;45(2):67-75

Authors: Sundfeld RH, Mauro SJ, Briso AL, Sundfeld ML

The clinical behavior of Concise and Prisma Shield sealants for pit and fissure was analyzed by clinical/photographic evaluation. A hematoxylin-based staining solution was applied to the occlusal surface 7 days, 18 months, 36 months, and 11 years after the occlusal sealing, thus allowing the sealant material on the surface to be checked. At each analysis time, each occlusal surface was photographed, and the photographs corresponding to each time were submitted to clinical/photographic evaluation. Although the sealant materials showed marginal alterations over time, they did not require reapplication because the region composed of the pit and fissure remained covered.

PMID: 15536857 [PubMed - indexed for MEDLINE]

The timing of subsequent treatment for teeth restored with large amalgams and crowns: factors related to the need for subsequent treatment.

J Dent Res. 2004 Nov;83(11):854-8

Authors: Kolker JL, Damiano PC, Jones MP, Dawson DV, Caplan DJ, Armstrong SR, Flach SD, Kuthy RA, Warren JJ

Crowns and large amalgams protect structurally compromised teeth to various degrees in different situations. The aim of this investigation was to evaluate the survival of teeth with these two types of restorations and the factors associated with better outcomes. Retrospective administrative and chart data were used. Survival was defined and modeled as: (1) receipt of no treatment and (2) receipt of no catastrophic treatment over five- and 10-year periods. Analyses included: Kaplan-Meier survival curves, Log-Rank tests, and Cox proportional hazards regression modeling. Crowns survived longer with no treatment and with no catastrophic treatment; however, mandibular large amalgams were least likely to have survived with no treatment, and maxillary large amalgams were least likely to have survived with no catastrophic treatment. Having no adjacent teeth also decreased survival. Crowns survived longer than large amalgams, but factors such as arch type and the presence of adjacent teeth contributed to the survival of large amalgams.

PMID: 15505235 [PubMed - indexed for MEDLINE]

Implantology and the severely resorbed edentulous mandible.

Crit Rev Oral Biol Med. 2004;15(4):240-8

Authors: Stellingsma C, Vissink A, Meijer HJ, Kuiper C, Raghoebar GM

Patients with a severely resorbed edentulous mandible often suffer from problems with the lower denture. These problems include: insufficient retention of the lower denture, intolerance to loading by the mucosa, pain, difficulties with eating and speech, loss of soft-tissue support, and altered facial appearance. These problems are a challenge for the prosthodontist and surgeon. Dental implants have been shown to provide a reliable basis for fixed and removable prostheses. This has resulted in a drastic change in the treatment concepts for management of the severely resorbed edentulous mandible. Reconstructive, pre-prosthetic surgery has changed from surgery aimed to provide a sufficient osseous and mucosal support for a conventional denture into surgery aimed to provide a sufficient bone volume enabling implants to be placed at the most optimal positions from a prosthetic point of view. The aim of this paper is to review critically the literature on procedures related to the severely resorbed edentulous mandible and dental implant treatment. The study includes the transmandibular implant, (short) endosseous implants, and reconstructive procedures such as distraction osteogenesis, augmentation of the mandibular ridge with autogenous bone, and bone substitutes followed by the placement of implants. The number of patients participating in a study, the follow-up period, the design of the study, the degree of mandibular resorption, and the survival rate of the dental implants all are considered evaluation parameters. Although numerous studies have described the outcome results of dental implants in the edentulous mandible, there have been few prospective studies designed as randomized clinical trials that compare different treatment modalities to restore the severely resorbed mandible. Therefore, it is not yet possible to select an evidence-based treatment modality. Future research has to be focused on long-term, detailed follow-up clinical trials before scientifically based decisions in treating these patients can be made. This will contribute to a higher level of care in this field.

PMID: 15284188 [PubMed - indexed for MEDLINE]

Abutment tooth loss in patients with overdentures.

J Am Dent Assoc. 2004 Jun;135(6):739-46; quiz 795-6

Authors: Ettinger RL, Qian F

BACKGROUND: Since the 1960s, the use of natural teeth as overdenture abutments has become part of accepted clinical practice. Several longitudinal studies have been conducted, but tooth loss has not been reported to be a significant problem. The aim of this study was to identify the incidence and causes of tooth loss in a prospective cohort study of subjects wearing overdentures. METHODS: The study, conducted between 1973 and 1994, evaluated 273 subjects (62.3 percent male) with a mean age of 59.6 years. RESULTS: Of the 273 subjects with 666 abutments, 74 lost 133 abutments. The most common cause of tooth loss was periodontal disease (29.3 percent) followed by periapical lesions (18.8 percent) and caries (16.5 percent). Through logistic regression, the authors found that subjects who lost teeth were more likely to have medical problems that could cause soft-tissue lesions of the oral mucosa, were less likely to use fluoride daily and were less likely to return for yearly recall visits. The authors found 22 vertical fractures in 17 subjects. Chi2 analysis revealed that overdenture teeth in the maxillary arch that were opposed by natural teeth were more likely to experience vertical fractures. CONCLUSIONS: In a study that followed up some patients for as long as 22 years, the rate of tooth loss was 20.0 percent. Many of these failures could have been prevented if patients had practiced better oral hygiene. CLINICAL IMPLICATIONS: The findings suggest that if a dentist recommends overdenture therapy, the patient needs to be examined regularly to reduce the risk of experiencing caries and periodontal disease. Also, if the abutments are in the maxilla and are opposed by natural teeth, the dentist should consider using thimble crowns to reduce the risk of vertical fractures.

PMID: 15270156 [PubMed - indexed for MEDLINE]

Clinical performance of large, all-ceramic CAD/CAM-generated restorations after three years: a pilot study.

J Am Dent Assoc. 2004 May;135(5):605-12

Authors: Reich SM, Wichmann M, Rinne H, Shortall A

BACKGROUND: Adhesively luted all-ceramic restorations preserve and stabilize weakened tooth structure, but there is little published information about the clinical performance of large, all-ceramic restorations. METHODS: In this pilot study, the authors placed 58 large, single-tooth, all-ceramic restorations in 26 patients using a computer-aided design/computer-aided manufacturing, or CAD/CAM, system (CEREC 2, Sirona Dental Systems GmbH, Bensheim, Germany). They documented the maximum height of the restoration and remaining cementoenamel junction, or CEJ. In 21 cases, rubber dam isolation was not possible during adhesive luting. They re-evaluated the restorations after three years according to the U.S. Public Health Service criteria. RESULTS: After three years, the authors rated 56 (97 percent) of the 58 restorations as Bravo or better in regard to marginal integrity, secondary caries (four could not be rated), discoloration and anatomical form. One restoration was rated as Charlie because of poor marginal integrity, and one restoration had to be replaced owing to a bulk fracture. The authors rated the adequacy of proximal contact and occlusal relationships as acceptable-to-good for all restorations. Neither the extent of the remaining enamel at the cavity margin nor application of a rubber dam had any statistically significant influence (chi2 test, P > .05) on the clinical performance of the restorations after three years. CONCLUSIONS: At the three-year recall appointment, the authors found that the adhesively luted all-ceramic restorations had successfully repaired large coronal defects, irrespective of the cavity margin location (that is, coronal or apical to the CEJ). CLINICAL IMPLICATIONS: Tooth-colored, all-ceramic CAD/CAM-generated restorations are an alternative to conventional restorations if large coronal defects need to be treated.

PMID: 15202752 [PubMed - indexed for MEDLINE]

Examiner agreement in the replacement decision of Class I amalgam restorations.

J Contemp Dent Pract. 2004 May 15;5(2):81-92

Authors: Ermis RB, Aydin U

The aim of this study was to investigate interexaminer and intraexaminer agreement in the replacement decision for Class I amalgam restorations. Three examiners evaluated the restorations clinically and with bitewing radiographs. One hundred and twelve restorations were evaluated for secondary caries, body fracture, deficient anatomic form (contour), ditched margins, and marginal overhangs. After one month, the assessments were repeated by the same examiners under the same conditions. Cohen's Kappa analysis was used to analyze the data. The number of replacement decisions varied from 12 to 27 and from 6 to 14 at the first and second evaluations, respectively. The Kappa statistics indicated "moderate" to "substantial" consistency for interexaminer and intraexaminer agreement in the replacement decisions based on clinical and radiographical examinations. Restorations with deficient anatomic form and marginal overhangs presented the most frequent diagnostic difficulties and lead to disagreement among examiners. The most frequently mentioned reasons for replacement were the restorations had ditched margins at both clinical evaluation periods and secondary caries was detected during radiographical evaluations. In the absence of agreement among examiners, clinical and radiographic guidelines are necessary for replacing Class I amalgam restorations.

PMID: 15150636 [PubMed - indexed for MEDLINE]

Informatics systems to assess and apply clinical research on dental restorative materials.

Adv Dent Res. 2003 Dec;17:43-8

Authors: Anusavice KJ

Dental biomaterials are used clinically for one or more of the following purposes: to restore function, to enhance esthetics, and to prevent or arrest demineralization of tooth structure. Studies of the clinical performance of restorations and prostheses made from these materials have generally focused on quality assessment and survival statistics. Data from these studies should provide probabilities of specific treatment outcomes that are useful for practicing dentists. However, the utility of these data is limited by the lack of national and international standards for assessing these clinical outcomes. Standardized approaches toward clinical informatics and treatment-decision analysis are urgently needed to minimize the variability of clinical outcomes reported in publications associated with direct and indirect restorative materials used for dental restorations and prostheses.

PMID: 15126206 [PubMed - indexed for MEDLINE]

In vivo versus in vitro microtensile bond strength of axial versus gingival cavity preparation walls in Class II resin-based composite restorations.

J Am Dent Assoc. 2004 Feb;135(2):185-93; quiz 228

Authors: Purk JH, Dusevich V, Glaros A, Spencer P, Eick JD

BACKGROUND: Gingival margins in Class II composite restorations are a site of frequent failure. The purpose of the authors' study was to compare the microtensile dentin bond strength of gingival and axial restored cavity preparation walls of Class II composite restorations under in vivo and in vitro conditions. METHODS: After obtaining informed consent, the authors placed Class II resin-based composite restorations in 14 premolar teeth from five patients, under in vivo or in vitro conditions. The teeth were sectioned to obtain rectangular specimens from axial and gingival walls with a surface area of approximately 0.5 square millimeter. The authors tested 85 microtensile adhesive samples from the 14 teeth on a testing instrument (Universal Instron, Model 125, Instron, Canton, Mass.) until failure. RESULTS: The mean (+/- standard deviation) mircotensile dentin bond strengths in mega-pascals were as follows: in vivo axial, 36.5 (14.9); in vivo gingival, 17.6 (11.6); in vitro axial, 49.5 (13.9); in vitro gingival, 34.0 (13.1). A two-way analysis of variance found a statistically significant difference between in vitro and in vivo conditions and between the axial and gingival walls (P < or = .001). Eighty-eight percent of the fractured samples involved the adhesive layer as observed under scanning electron microscopy up to x2,500. Seventeen of the gingival samples and two of the axial samples debonded during the preparation phase and could not be tested. CONCLUSION: The dentinal microtensile strength of adhesive/resin-based composite bonded to the gingival wall was significantly weaker than the bond to the axial wall, and in vivo conditions produced significantly weaker bond strengths than did in vitro conditions. CLINICAL IMPLICATIONS: The dentinal adhesive bond of resin-based composite to gingival walls is significantly weaker and thus more subject to failure than the bond to axial walls. In vitro bond strength studies may overestimate the bond strength of adhesives in in vivo applications.

PMID: 15005434 [PubMed - indexed for MEDLINE]

Dental endosseous implants: an update.

J Am Dent Assoc. 2004 Jan;135(1):92-7

Authors:

BACKGROUND: The ADA Council on Scientific Affairs has developed an updated report on endosseous implants to aid dental professionals in considering and incorporating practical applications of implantation therapy in general practice. OVERVIEW: This report addresses the demonstrated high success rates of multiple implant designs in various clinical situations, the factors contributing to elevated risk of implant failure and implantation therapy as a comprehensive process of patient care. The Council also provides a list of products available to the profession that have received the ADA Seal of Acceptance. CONCLUSIONS AND PRACTICE IMPLICATIONS: The Council recommends that practitioners use implantation therapies and systems judiciously in accordance with the current best evidence. The Council also urges evaluators to use common and consistent criteria for reporting the outcomes assessment in clinical studies of various implant treatments.

PMID: 14959881 [PubMed - indexed for MEDLINE]

Clinical evaluation of packable and conventional hybrid resin-based composites for posterior restorations in permanent teeth: results at 12 months.

J Am Dent Assoc. 2003 Dec;134(12):1581-9

Authors: Yip KH, Poon BK, Chu FC, Poon EC, Kong FY, Smales RJ

BACKGROUND: Packable resin-based composites and simplified resin bonding systems are marketed to offer many advantages over conventional posterior hybrid composites and total-etch bonding systems. The authors conducted a study to evaluate the initial clinical performances of a packable and a conventional hybrid resin-based composite used with a simplified bonding system. METHODS: A total of 57 Class I and 45 Class II restorations were placed in the permanent teeth of 65 adult patients. The carious lesions were restored with either packable resin-based composite (SureFil, Dentsply DeTrey GmbH, Konstanz, Germany) or conventional hybrid resin-based composite (SpectrumTPH, Dentsply DeTrey GmbH), using a resin adhesive (Non-Rinse Conditioner and Prime & Bond NT, both manufactured by Dentsply DeTrey GmbH). The authors evaluated the restorations using U.S. Public Health Service-Ryge modified criteria (in which Alfa is the highest rating) and by using color transparencies and die stone replicas. RESULTS: Three SureFil restorations failed before their baseline evaluation. There were no failures among the 78 SpectrumTPH restorations evaluated at 12 months. For both resin-based composites, Alfa ratings were 90 percent or higher for marginal discoloration, anatomical form, surface texture and surface staining. Lower percentages of restorations were rated Alfa for color match, marginal integrity and gingival health. Occasional mild postoperative sensitivity was reported for four SureFil restorations and one SpectrumTPH restoration. The mean occlusal wear rate was 38 micrometers for the larger SureFil restorations and 25 microm for the smaller SpectrumTPH restorations. CONCLUSIONS: The 12-month clinical performances of the two restorative materials were satisfactory and not significantly different for each of the parameters evaluated. CLINICAL IMPLICATIONS: A packable and a conventional hybrid resin-based composite placed with a simplified bonding system in posterior permanent teeth showed satisfactory and similar results after 12 months.

PMID: 14719754 [PubMed - indexed for MEDLINE]