In vitro evaluation of the effectiveness of the chemomechanical preparation against Enterococcus faecalis after single- or multiple-visit root canal treatment.

Braz Oral Res. 2007;21(4):308-313

Authors: Gurgel-Filho ED, Vivacqua-Gomes N, Gomes BP, Ferraz CC, Zaia AA, Souza-Filho FJ

The purpose was to assess the elimination of Enterococcus faecalis in vitro in human mandibular premolars after chemomechanical preparation with or without the use of a calcium hydroxide dressing. After 60 days of contamination with E. faecalis, the root canals were prepared using the Crown-Down technique combined with 2% chlorhexidine gel irrigation. Then, the specimens were divided into two experimental groups, treated in a single visit or in multiple visits, and two control groups. The multiple-visit group received a dressing with calcium hydroxide for 14 days (CalenTM) and the single-visit group did not receive any medication. In the two control groups, the canals were filled with BHI after chemomechanical preparation with 2% chlorhexidine gel or distilled water. Microbial samples were taken from the root canals for colony forming unit count for each phase of the treatment using sterile paper points inside the root canal lumen. Data were ranked and analyzed by the Kruskal-Wallis statistical test. The residual microbial colonies were then assessed. The results showed that chemomechanical preparation using 2% chlorhexidine gel with no intra-canal dressing reduced by 100% the E. faecalis contamination of the root canal lumen. The calcium-hydroxide group that received the 14-day intra-canal dressing allowed a small number of bacteria to grow between visits, but without statistical differences between groups.

PMID: 18060256 [PubMed - as supplied by publisher]

Effectiveness of a silicon-based root canal sealer for filling of simulated lateral canals.

Braz Dent J. 2007;18(1):20-3

Authors: Barbizam JV, Souza M, Cecchin D, Dabbel J

The purpose of this in vitro study was to evaluate the ability of a silicon-based root canal sealer, compared to zinc oxide and eugenol and an epoxy resin-based sealers, for filling of simulated lateral canals. Thirty extracted single-rooted human teeth were selected, conventional access was made and the working length was established 1 mm from the apical foramen. Three simulated lateral canals, one in each root third (coronal, middle and apical) were prepared in both the mesial and distal surfaces of each tooth using a size 15 reamer adapted to a low-speed handpiece. Each root canal was instrumented using ProTaper rotary files up to file F3 at the working length, and then irrigated with 2.5% NaOCl followed by EDTA. The teeth were assigned to 3 groups (n=10), according to the root canal sealer: Roeko Seal (Group 1), Sealer 26 (group 2) and Grossman's sealer (Group 3). Gutta-percha cold lateral condensation technique was performed in all groups. Postoperative radiographs were taken and the images were projected for evaluation of the quality of lateral canal filling. Data were submitted to statistical analysis by Kruskal Wallis test at 5% significance level. The results showed that Grossman's sealer filled a larger number of lateral canals than Roeko Seal (p<0.05) and Sealer 26 (p<0.01). It may be concluded that Roeko Seal silicone-based root canal sealer was not as effective as the Grossman's sealer for filling of simulated lateral canals. The lateral canals localized in the apical third of the root were more difficult to be filled.

PMID: 17639195 [PubMed - indexed for MEDLINE]

Residual antibacterial activity of chlorhexidine digluconate and camphorated p-monochlorophenol in calcium hydroxide-based root canal dressings.

Braz Dent J. 2007;18(1):8-15

Authors: Soares JA, Leonardo MR, Tanomaru Filho M, Silva LA, Ito IY

The purpose of this study was to evaluate the residual antibacterial activity of several calcium hydroxide [Ca(OH)2]-based pastes, placed in root canals of dogs' teeth with induced chronic periapical lesions. Root canals were instrumented with the ProFile rotary system and filled with 4 pastes: G1 (n=16): Ca(OH)2 paste + anesthetic solution; G2 (n=20): Calen paste + camphorated p-monochlorophenol (CMCP); G3 (n=18): Calen; and G4 (n=18): Ca(OH)2 paste + 2% chlorhexidine digluconate. After 21 days, the pastes were removed with size 60 K-files and placed on Petri plates with agar inoculated with Micrococcus luteus ATCC 9341. Pastes that were not placed into root canals served as control. After pre-diffusion, incubation and optimization, the inhibition zones of bacterial growth were measured and analyzed by Mann-Whitney U test at 5% significance level. All pastes showed residual antibacterial activity. The control samples had larger halos (p<0.05). The mean residual antibacterial activity halos in G1, G2, G3 and G4 were 7.6; 10.4; 17.7 and 21.4 mm, respectively. The zones of bacterial growth of G4 were significantly larger than those of G1 and G2 (p<0.05). In conclusion, regardless of the vehicle and antiseptic, all Ca(OH)2-based pastes showed different degrees of measurable residual antibacterial activity. Furthermore, unlike CMCP, chlorhexidine increased significantly the antibacterial activity of Ca(OH)2.

PMID: 17639193 [PubMed - indexed for MEDLINE]

Susceptibility of Enterococcus faecalis biofilm to antibiotics and calcium hydroxide.

J Oral Sci. 2007 Jun;49(2):161-6

Authors: Chai WL, Hamimah H, Cheng SC, Sallam AA, Abdullah M

The purpose of this study was to investigate the antimicrobial efficacy of six groups of antibiotics and calcium hydroxide against Enterococcus faecalis biofilm in a membrane filter model. Two-day-old E. faecalis (ATCC 29212) biofilm was exposed to ampicillin, co-trimoxazole, erythr omycin, oxytetracycline, vancomycin, vancomycin followed by gentamicin, Ca(OH)(2), and phosphate-buffered saline (control). After 1 h of exposure, the antimicrobial activity was neutralized by washing each disc five times in PBS, and then the colony-forming units of the remaining viable bacteria on each disc were counted. The results revealed that only erythromycin, oxytetracycline and Ca(OH)(2) showed 100% biofilm kill. An ANOVA with a Bonferroni post hoc test (P < 0.05) detected significant differences among the test agents, except in the ampicillin group versus the co-trimoxazole group. It is concluded that erythromycin, oxytetracycline and Ca(OH)(2) are 100% effective in eliminating E. faecalis biofilm, whereas ampicillin, co-trimoxazole, vancomycin, and vancomycin followed by gentamicin are ineffective. (J. Oral Sci. 49, 161-166, 2007).

PMID: 17634730 [PubMed - in process]

Apical surgery with calcium hydroxide capping of the exposed dentine: a case report.

J Oral Sci. 2007 Mar;49(1):79-83

Authors: Soares JA, Silveira FF, Nunes E

Among a variety of biomaterials that have been reported to be ideal for dental repair, calcium hydroxide has been shown to have excellent long-term biocompatibility in the pulp and periapical areas. Here we report an alternative method employing calcium hydroxide for periapical surgery in a patient who developed internal apical resorption after traumatic injury, which negatively affected the quality of the cleaning, shaping and filling of the root canal. Obturation of the root canal as far as the middle third was followed by apicoectomy and ultrasonic retropreparation, and then retrograde root filling with resin cement sealer (Sealer 26) and zinc oxide powder. Calcium hydroxide paste was applied over the exposed dentinal surface, forming a barrier over the root apex. Radiographic follow-up after 24 months showed absence of apical resorption and complete periapical bone repair associated with a continuous apical lamina dura. (J. Oral Sci. 49, 79-83, 2007).

PMID: 17429187 [PubMed - in process]

Effect of intracanal medication with calcium hydroxide and 1% chlorhexidine in endodontic retreatment cases with periapical lesions: an in vivo study.

J Formos Med Assoc. 2007 Mar;106(3):217-24

Authors: Ercan E, Dalli M, Du&#xFC;lgergil CT, Yaman F

BACKGROUND/PURPOSE: Calcium hydroxide (Ca(OH)(2)) has been widely used as an intracanal medicament for endodontic retreatment, but very few studies used both Ca(OH)(2) and 1% chlorhexidine (CHX) as intracanal medicaments. The purpose of this study was to assess the in vivo effectiveness of a combination of Ca(OH)(2) and 1% CHX as intracanal medicaments in endodontic retreatment cases with periapical lesions. METHODS: Previous cases of endodontically treated teeth with periapical pathosis in 70 patients (36 men and 34 women, age range 18-60 years) were included. Of these teeth, 59 had received root canal treatment and 11 had been subjected to previous apical surgery, indicating endodontic failure. Following the routine procedures, including canal reshaping and irrigation with 2% CHX, a canal medication material containing Ca(OH)(2) powder and a 1% CHX solution was placed into the root canals. Over a 6-week period, the intracanal medication was periodically changed until the teeth became asymptomatic. Patients were recalled at 3-month intervals for radiographic and clinical examination. RESULTS: Our clinical and radiographic assessment of retreatment cases showed complete healing in 41 (64%) teeth, incomplete healing in 9 (14%) teeth, and failure in 14 (22%) teeth. For complete healing teeth, the healing time varied from 6 to 36 months. The size of the periapical lesions and previous surgical treatment had no influence on the prognosis. CONCLUSION: Our results suggest that a combination of Ca(OH)(2) and 1% CHX can be successfully used as intracanal medicament for disinfection in endodontic retreatment cases with periapical lesions.

PMID: 17389166 [PubMed - indexed for MEDLINE]

In vitro antimicrobial activity of different gutta-percha points and calcium hydroxide pastes.

Braz Oral Res. 2007 Jan-Mar;21(1):35-9

Authors: Tanomaru JM, Pappen FG, Tanomaru Filho M, Spolidorio DM, Ito IY

The aim of this study was to evaluate the antimicrobial activity of different trademarks and compositions of gutta-percha points and calcium hydroxide pastes used in endodontic therapy. The evaluated material consisted of gutta-percha points containing calcium hydroxide (Roeko), gutta-percha points containing chlorhexidine (Roeko), two conventional gutta-percha points (Endo Points and Roeko) and two calcium hydroxide pastes (Calen and Calen/PMCC). Antimicrobial tests included five species of microorganisms: Escherichia coli (ATCC10538), Staphylococcus epidermidis (ATCC12228), Staphylococcus aureus (ATCC6538), Pseudomonas aeruginosa (ATCC27853), and Micrococcus luteus (ATCC9341). The Agar diffusion method was employed. The plates were kept at room temperature for 2 h for prediffusion and then incubated at 37 degrees C for 24 h. The triphenyltetrazolium chloride gel was added for optimization and the zones of inhibition were measured. Statistical evaluation was carried out using analysis of variance and Tukey Test. The obtained results showed that all microbial species used in the study were inhibited by the gutta-percha points containing chlorhexidine and by the calcium hydroxide pastes (Calen and Calen/PMCC), with similar results (p > 0.05). No antimicrobial activity was observed for the other groups. It was concluded that the gutta-percha points containing chlorhexidine presented antimicrobial activity, whereas the gutta-percha points containing calcium hydroxide did not.

PMID: 17384853 [PubMed - in process]

Antimicrobial analysis of different root canal filling pastes used in pediatric dentistry by two experimental methods.

Braz Dent J. 2006;17(4):317-22

Authors: Amorim Lde F, Toledo OA, Estrela CR, Decurcio Dde A, Estrela C

The objective of this study was to compare, by two experimental methods, the antimicrobial efficacy of different root canal filling pastes used in pediatric dentistry. The tested materials were: Guedes-Pinto paste (GPP), zinc oxide-eugenol paste (OZEP), calcium hydroxide paste (CHP), chloramphenicol + tetracycline + zinc oxide and eugenol paste (CTZP) and Vitapex. Fiven microbial strains (S. aureus, E. faecalis, P. aeruginosa, B. subtilis and C. albicans) obtained from the American Type Culture Collection were inoculated in Brain Heart Infusion (BHI) and incubated at 37 degrees C for 24 h. For the direct exposure test (DET), 72 paper points were contaminated with the standard microbial suspensions and exposed to the root canal filling pastes for 1, 24, 48 and 72 h. The points were immersed in Letheen Broth (LB), followed by incubation at 37 degrees C for 48 h. An inoculum of 0.1 mL obtained from LB was then transferred to 7 mL of BHI, under identical incubations conditions and the microbial growth was evaluated. The pastes showed activity between 1 and 24 h, depending on the material. For the agar diffusion test (ADT), 30 Petri plates with 20 mL of BHI agar were inoculated with 0.1 mL of the microbial suspension, using sterile swabs that were spread on the medium. Three cavities were made in each agar plate (total = 90) and completely filled with one of the filling root canal pastes. The plates were pre-incubated for 1 h at room temperature and then incubated at 37 degrees C for 24 to 48 h. The inhibition zone around each well was recorded in mm. The complete antimicrobial effect in the direct exposure test was observed after 24 h on all microbial indicators. All root canal filling materials induced the formation of inhibition zones, except for Vitapex (range, 6.0-39.0 mm).

PMID: 17262146 [PubMed - indexed for MEDLINE]

In vitro evaluation of the antimicrobial activity of endodontic sealers.

Braz Oral Res. 2006 Oct-Dec;20(4):303-6

Authors: Miyagak DC, de Carvalho EM, Robazza CR, Chavasco JK, Levorato GL

The purpose of this study is to evaluate the antimicrobial activity of the endodontic sealers: N-Rickert, Sealapex, AH Plus, Mineral Trioxide Aggregate (MTA) and portland cement. The Agar diffusion method was used in plates previously inoculated with the following microorganisms: C. albicans, S. aureus, E. faecalis, E. coli. The diameters of microbial inhibition zones were measured after 24 hours of incubation in kiln at 37 degrees C. According to the methodology used, it was possible to conclude that only the sealers AH Plus and N-Rickert presented antimicrobial activity against C. albicans, S. aureus, and E. coli; no antimicrobial activity in MTA, Sealapex and portland cement was observed. N-Rickert presented the largest inhibition zones varying from 8 to 18 mm, and the microorganism E. faecalis was resistant against all sealers tested.

PMID: 17242789 [PubMed - indexed for MEDLINE]

A scanning electron microscopic evaluation of root canal wall cleanliness after calcium hydroxide removal using three irrigation regimens.

J Contemp Dent Pract. 2007 Jan 1;8(1):11-8

Authors: Naaman A, Kaloustian H, Ounsi HF, Naaman-Bou Abboud N, Ricci C, Medioni E

AIMS: The aims of this in vitro study were to evaluate debris and smear layer elimination capability effectiveness of 5.25% sodium hypochlorite (NaOCl) after calcium hydroxide removal from the root canal and to determine if ethylenediaminetetraacetic acid (EDTA) and citric acid have any additional effects on debris and smear layer removal. METHODS AND MATERIALS: All irrigation regimens are associated with ultrasonics. Thirty-six pulpless single-rooted teeth were divided into three groups on the basis of the irrigation regimen, namely 5.25% NaOCl alone, 5.25% NaOCl with 17% EDTA pH 7 (NaOCl-EDTA), and 5.25% NaOCl with 50% citric acid (NaOCl-CA). All root canals were instrumented with the Protaper rotary system (Dentsply-Maillefer, Ballaigues, Switzerland) using a crown-down approach. The apical foramen of each tooth was enlarged to a size 30 with a 0.09 taper. After longitudinal sectioning, the dentin walls were microphotographed using scanning electron microscopy (SEM) at a 1500x magnification. Using a grid and a 5-step scale these microphotographs were scored by three investigators in order to evaluate debris and smear layer residuals. Data were statistically evaluated using Kruskal-Wallis and Mann-Whitney tests. RESULTS: In the coronal third the lowest score obtained with NaOCl-CA was similar to NaOCl-EDTA. When using NaOCl-EDTA, mean debris scores were similar to the control group (NaOCl) and lower than NaOCl-CA in the middle and apical thirds. Regarding the mean smear layer score, NaOCl-CA was the lowest in the coronal, middle, and apical thirds with a statistically significant difference (p < 0.001). CONCLUSION: When the total surface of the root was evaluated, NaOCl-EDTA was superior in removing debris, but the association of NaOCl-CA enabled the most effective removal of the smear layer.

PMID: 17211500 [PubMed - indexed for MEDLINE]

Histologic evaluation of pulpotomy performed with ethyl-cyanoacrylate and calcium hydroxide.

Braz Oral Res. 2006 Jul-Sep;20(3):226-30

Authors: de Albuquerque DS, Gominho LF, Dos Santos RA

The aim of this study was to evaluate histological aspects of the pulp-dentin complex of dogs submitted to pulpotomy and capped with ethyl-cyanoacrylate and calcium hydroxide. Thirty dog teeth were divided into 2 groups of 15 as follows: Group 1 - ethyl-cyanoacrylate; Group 2 - calcium hydroxide. The pulpotomies were carried out following all of the treatment precautions recommended for dogs. After 30 days the specimens were submitted to histological preparation and were then blindly evaluated by a histologist. Data were analyzed statistically by the Fisher exact test, comparing the two groups. After 30 days, the presence of a hard tissue barrier was observed in 83.3% of Group 1, and in 100% of Group 2 (p = 0.478). A continuous hard tissue barrier was observed in 50% of the ethyl-cyanoacrylate group and 75% of the calcium hydroxide group (p = 0.652). It can be concluded that both materials induced hard tissue barrier formation, but Group 2 had a higher percentage than Group 1, with no significant statistical differences; the differences observed between the different barriers (continuous/non-continuous) were not significant between groups and there was no pulpal necrosis in either group.

PMID: 17119705 [PubMed - indexed for MEDLINE]

Biological response of pulps submitted to different capping materials.

Braz Oral Res. 2006 Jul-Sep;20(3):219-25

Authors: Briso AL, Rahal V, Mestrener SR, Dezan Junior E

Pulp capping is a procedure that comprises adequate protection of the pulp tissue exposed to the oral environment, aiming at the preservation of its vitality and functions. This study evaluated the response of the dental pulps of dog teeth to capping with mineral trioxide aggregate (MTA) or calcium hydroxide P.A. For that purpose, 37 teeth were divided into two groups, according to the capping material employed. Two dogs were anesthetized and, after placement of a rubber dam, their pulps were exposed in a standardized manner and protected with the experimental capping materials. The cavities were then sealed with resin-modified glass ionomer cement and restored with composite resin. After sixty days, the animals were killed and the specimens were processed in order to be analyzed with optic microscopy. It was observed that MTA presented a higher success rate compared to calcium hydroxide, presenting a lower occurrence of infection and pulp necrosis.

PMID: 17119704 [PubMed - indexed for MEDLINE]

An in vitro evaluation of pH variations in calcium hydroxide liners.

J Indian Soc Pedod Prev Dent. 2006 Sep;24(3):144-5

Authors: Subramaniam P, Konde S, Prashanth P

The purpose of this present study was to determine the pH changes of five different commercially available calcium hydroxide liners and variations of pH at different time intervals. The following commercially available materials were investigated: Dycal (LD Caulk); Calcimol (Vocco Products); calcium hydroxide powder (Deepti Products); Calcimol LC (Vocco Products); Lime-Lite (Pulpdent Corporation). Five samples were prepared from each liner. The pH measurements were recorded at time intervals of 1 h, 24 h, 3 days and 7 days after mixing of the liner. The pH variations of each material at the given time intervals were recorded and the means were calculated. Comparison of the mean values at all time intervals with the statistical analysis showed significantly high differences (P < 0.001) between pH values induced by each material at all time intervals. Among the water-insoluble products, Dycal had the strongest alkaline effect after 7 days interval. The materials that chemically hardened produced higher pH values than materials that hardened by a visible light source after 7 days.

PMID: 17065782 [PubMed - indexed for MEDLINE]

Effect of rotary instrumentation and of the association of calcium hydroxide and chlorhexidine on the antisepsis of the root canal system in dogs.

Braz Oral Res. 2006 Apr-Jun;20(2):120-6

Authors: Soares JA, Leonardo MR, da Silva LA, Tanomaru Filho M, Ito IY

This study aimed at evaluating the antisepsis of the root canal system (RCS) and periapical region (PR) provided by rotary instrumentation associated with chlorhexidine + calcium hydroxide as intracanal medicament. Chronic periapical lesions were induced in 26 pre-molar roots in two dogs. After microbiological sampling, automatic instrumentation using the Profile system and irrigation with 5.25% sodium hypochlorite solution, with a final rinse of 14.3% EDTA followed by profuse irrigation with physiological saline were carried out in 18 root canals. After drying the canals, a paste based on calcium hydroxide associated with a 2% chlorhexidine digluconate solution was placed inside them. After 21 days, the medication was removed, leaving the root canals empty and coronally sealed. After 96 hours, a final microbiological sample was obtained, followed by histomicrobiological processing by the Brown & Brenn method. Eight untreated root canals represented the control group (C-G). Based on the Mann-Whitney test at a confidence level of 5% (p < 0.05), the procedures of antisepsis used offered significant efficacy (p < 0.05) resulting in 100.0% of the canals free of microorganisms. In the C-G, an elevated incidence of various microbial morphotypes was confirmed in all sites of the RCS, with the presence of microbial colonies in the periapical region. In contrast, the experimental group showed a similar pattern of infection in the RCS, although less intense and a reduced level of periapical infection (p < 0.05). It was concluded that adequate instrumentation followed by the application of calcium hydroxide + chlorhexidine offered significant elimination of microorganisms.

PMID: 16878204 [PubMed - indexed for MEDLINE]

Treatment of pulp floor and stripping perforation by mineral trioxide aggregate.

J Formos Med Assoc. 2006 Jun;105(6):522-6

Authors: Tsai YL, Lan WH, Jeng JH

Mineral trioxide aggregate (MTA) has been widely used to repair various kinds of tooth perforations, but its use for obturation of the entire root canal has not been reported. We report two cases of tooth perforation successfully repaired with MTA. The first patient was a 78-year-old male with calcified canal and pulp floor perforation in the left maxillary first premolar. After bypass of the calcified palatal canal, both buccal and palatal canals were filled with gutta percha, and the pulp floor perforation was repaired with MTA. Clinical success with no evident radicular lesion was found at the 18-month follow-up. The second patient was a 51-year-old female with a stripping perforation in a C-shaped root canal of the right mandibular second molar detected after removal of a post. Following root canal debridement and calcium hydroxide therapy to control inflammation at the stripping perforation site, apical and furcation bone healing were observed by radiographic examination. The stripping perforation was repaired by obturation of the entire C-shaped root canal with MTA. Observation at the 9-month follow-up revealed bone healing without any clinical symptoms and signs. These cases suggest that MTA is an alternative root canal obturation material for treatment of stripping perforation in a C-shaped root canal and for repair of pulp floor perforation.

PMID: 16801043 [PubMed - indexed for MEDLINE]

Endodontic management of taurodontic teeth.

Indian J Dent Res. 2005 Oct-Dec;16(4):177-81

Authors: Prakash R, Vishnu C, Suma B, Velmurugan N, Kandaswamy D

Taurodontism is a morpho-anatomical change in the shape of the tooth in which the body of the tooth is enlarged and the roots are reduced in size. Although taurodontism is a dental rarity, this unusual radicular form should merit circumspect considerations in planning and treatment. Endodontic management in taurodont teeth has been described as complex and difficult. The present paper describes the successful completion of endodontic treatment in three taurodontic teeth with appropriate use of instruments and techniques and also emphasizes the need for post endodontic rehabilitation.

PMID: 16761713 [PubMed - indexed for MEDLINE]

Mineral trioxide aggregate pulpotomies: a case series outcomes assessment.

J Am Dent Assoc. 2006 May;137(5):610-8

Authors: Witherspoon DE, Small JC, Harris GZ

BACKGROUND: The greatest threats to developing teeth are dental caries and traumatic injury. A primary goal of all restorative treatment is to maintain pulp vitality so that normal root development or apexogenesis can occur. If pulpal exposure occurs, then a pulpotomy procedure aims to preserve pulp vitality to allow for normal root development. Historically, calcium hydroxide has been the material of choice for pulpotomy procedures. Recently, an alternative material called mineral trioxide aggregate (MTA) has demonstrated the ability to induce hard-tissue formation in pulpal tissue. The authors describe the clinical and radiographic outcome of a series of cases involving the use of MTA in pulpotomy procedures. METHODS: Twenty-three cases in 18 patients were treated with MTA pulpotomy procedures in an endodontic private practice. All of the patients had been referred to the practice for diagnosis and treatment of a symptomatic tooth. All of the authors provided treatment. Pulpal exposures were either due to caries or complicated enamel dentin fractures. RESULTS: Nineteen teeth in 14 patients were available for recall. The mean time of recall was 19.7 months. Of the 19 cases, 15 involved healed teeth, and three involved teeth that were healing. One of 19 cases involved a tooth with persistent disease. CONCLUSIONS: MTA may be useful as a substitute for calcium hydroxide in pulpotomy procedures. Further research, however, is required to clarify this conclusion. CLINICAL IMPLICATIONS: MTA conceivably could replace calcium hydroxide as the material of choice for pulpotomy procedures, if future research continues to show promising results.

PMID: 16739540 [PubMed - indexed for MEDLINE]

Complicated crown fracture: a case report.

Braz Dent J. 2006;17(1):83-6

Authors: Fidel RA, Carvalho RG, Varela CH, Letra A, Fidel SR

This case report describes the treatment of a severe crown fracture of an immature mandibular permanent incisor in a 12 year-old boy referred to the Dental Traumatology Center of UNIGRANRIO University. After conventional endodontic procedures and dressing with calcium hydroxide, an apical plug was made with mineral trioxide aggregate in order to avoid an overflow of gutta-percha and endodontic sealer into the periapical tissues. Two years later, the tooth was clinically asymptomatic and radiographs showed total repair of the apical lesion.

PMID: 16721473 [PubMed - indexed for MEDLINE]

[Antibacterial effect of Jinzhi Hanshuye on infected root canals]

Shanghai Kou Qiang Yi Xue. 2006 Feb;15(1):15-8

Authors: Liu CH, Yin SH, Chen L

PURPOSE: To evaluate antibacterial effects of Jinzhi Hanshuye on infected root canals. METHODS: 30 infected single-root-canals were collected from 27 clinical patients, and randomly divided into two groups. In the experimental group, Jinzhi Hanshuye was used as irrigating solution and intracanal medicament, while in the control group tosylchloramide sodium irrigating and calcium hydroxide disinfecting root canals were adopted. Microbiological sampling was performed before treatment, after instrumentation, and after intracanal medication. The frequency of positive culture and CFU of each culture were evaluated by ANOVA. RESULTS: The frequency of positive culture was dropped from 73.3% to 46.7% after instrumentation and to 13.3% after medication in the experimental group, while in the control group the frequency was dropped from 73.3% to 20.0% and 26.7% after medication (P=0.9721). CFU was dropped from 1462.9 to 27.9 after instrumentation and 15.7 after medication, while in the control group CFU was dropped from 1402.8 to 14.0 and 45.1 after medication (P=0.688). CONCLUSIONS: Jinzhi Hanshuye had good antibacterial effects on anaerobics of infected root canals.

PMID: 16525601 [PubMed - in process]

[Treatment of teeth with open apices using mineral trioxide aggregate as apical barrier]

Shanghai Kou Qiang Yi Xue. 2006 Feb;15(1):7-10

Authors: Xu Q, Lin JQ, Huang F, Liu JW

PURPOSE: To evaluate the clinical effect of treatment of teeth with open apices using mineral trioxide aggregate (MTA) as apical barrier under surgical operating microscope. METHODS: The root canals of 23 teeth with open apices were cleaned and shaped, and disinfected with calcium hydroxide. The MTA mixture were then carried into the apical part of the root canals to create a 3-5 mm apical barrier. The remainder of the canals were filled with AH plus and Obtura II gutta-percha. The revisit times, the period and result of the treatment were recorded for all cases. RESULTS: The treatment of all cases was accomplished within 2 or 3 weeks. Postoperative X-ray films showed that the canals of 16 teeth were obturated very well. 7 teeth showed 1-2 mm over-filling. All recalled patients declared their teeth to be asymptomatic. The recall radiographs indicated that the apical radiolucent areas of teeth with pre-existing apical lesion decreased apparently or disappeared completely. No new radiolucency was found around the roots. CONCLUSION: MTA is effective and quick in treatment of teeth with open apices, even thought there is slight over-filling of the material.

PMID: 16525599 [PubMed - in process]

Periapical cyst repair after nonsurgical endodontic therapy: case report.

Braz Dent J. 2005;16(3):254-8

Authors: Valois CR, Costa-J&#xFA;nior ED

This article presents the procedures that must be considered for periapical cyst repair after nonsurgical endodontic treatment. The case of a periapical cyst associated to the left maxillary lateral incisor is reported. Nonsurgical root canal therapy was performed and lesion healing was confirmed radiographically after 24 months. Differential diagnosis, endodontic infection control, apical foramen enlargement and filling of the cystic cavity with a calcium hydroxide paste were important procedures for case resolution.

PMID: 16429195 [PubMed - in process]

In vitro evaluation of the susceptibility of endodontic pathogens to calcium hydroxide combined with different vehicles.

Braz Dent J. 2005;16(3):175-80

Authors: Vianna ME, Gomes BP, Sena NT, Zaia AA, Ferraz CC, Souza Filho FJ

The aim of this study was to investigate in vitro the antimicrobial activity of calcium hydroxide [Ca(OH)2] in combination with different vehicles against endodontic pathogens. For such purpose, a broth dilution test was performed. Pastes were prepared with Ca(OH)2 powder and the following vehicles: sterile water, glycerin, camphorated monochlorophenol (CMCP), CMCP + glycerin, polyethyleneglycol and CMCP + polyethyleneglycol. The time required for the pastes to produce negative cultures against the tested microorganisms was recorded and analyzed statistically using the Kruskal Wallis test at 5% significance level. Timing for pastes to eliminate the aerobic and facultative anaerobic microorganisms ranged from 6 to 24 h, while strict anaerobic microorganisms were inhibited within 30 s to 5 min. Microbial susceptibility, ranked from weakest to strongest, can be presented as follows: Enterococcus faecalis (the most resistant microorganism), Candida albicans, Staphylococcus aureus, Porphyromonas gingivalis, Porphyromonas endodontalis and Prevotella intermedia (the last two microorganisms required the same time to be eliminated). In conclusion, calcium hydroxide pastes needed more time to eliminate facultative than anaereobic microorganisms. These findings suggest that the antimicrobial property is related both to paste formulation and to microbial susceptibility.

PMID: 16429180 [PubMed - in process]

Detection of hydrogen gas-producing anaerobes in refuse-derived fuel (RDF) pellets.

Biosci Biotechnol Biochem. 2005 Nov;69(11):2081-5

Authors: Sakka M, Kimura T, Ohmiya K, Sakka K

Recently, we reported that refuse-derived fuel (RDF) pellets contain a relatively high number of viable bacterial cells and that these bacteria generate heat and hydrogen gas during fermentation under wet conditions. In this study we analyzed bacterial cell numbers of RDF samples manufactured with different concentrations of calcium hydroxide, which is usually added to waste materials for the prevention of rotting of food wastes and the acceleration of drying of solid wastes, and determined the amount of hydrogen gas produced by them under wet conditions. Furthermore, we analyzed microflora of the RDF samples before and during fermentation by denaturing gradient gel electrophoresis of 16S rDNA followed by sequencing. We found that the RDF samples contained various kinds of clostridia capable of producing hydrogen gas.

PMID: 16306688 [PubMed - indexed for MEDLINE]

Effectiveness of 4 pulpotomy techniques--randomized controlled trial.

J Dent Res. 2005 Dec;84(12):1144-8

Authors: Huth KC, Paschos E, Hajek-Al-Khatar N, Hollweck R, Crispin A, Hickel R, Folwaczny M

Pulpotomy is the accepted therapy for the management of cariously exposed pulps in symptom-free primary molars; however, evidence is lacking about the most appropriate technique. The aim of this study was to compare the relative effectiveness of the Er:YAG laser, calcium hydroxide, and ferric sulfate techniques with that of dilute formocresol in retaining such molars symptom-free. Two hundred primary molars in 107 healthy children were included and randomly allocated to one of the techniques. The treated teeth were blindly re-evaluated after 6, 12, 18, and 24 months. Descriptive data analysis and logistic regression analysis, accounting for each patient's effect by a generalized estimating equation (GEE), were used. After 24 months, the following total and clinical success rates were determined (%): formocresol 85 (96), laser 78 (93), calcium hydroxide 53 (87), and ferric sulfate 86 (100). Only calcium hydroxide performed significantly worse than formocresol (p = 0.001, odds ratio = 5.6, 95% confidence interval 2.0-15.5). In conclusion, calcium hydroxide is less appropriate for pulpotomies than is formocresol.

PMID: 16304444 [PubMed - indexed for MEDLINE]

[Antimicrobial activity "in vitro" of calcium hydroxide and tergentol on different concentrations in oral bact&#xE9;ria]

Acta Cir Bras. 2005;20 Suppl 1:27-33

Authors: Seabra EJ, Lima IP, Barbosa SV, Lima KC

PURPOSES: This research desenvolved in Rio Grande do Norte Federal University, Department of Dentistry purpose evaluation "in vitro" Ca(OH) and tergentol solutions action in oral cavity that first reside in and cariogenic microorganisms for dental biofilm chemical control increasing. METHODS: "In vitro" tests with antibiogram discs and biofilm formers bacteria antibiothic action from Ca(OH) and tergentol solutions and the 0.12% clorhexydine digluconate as "gold-standard". RESULTS: The results were analyzed using the Kruskal-Wallis test and Dunn's multiple comparison post-test with p-value always lower than 0,05. The clorhexydine showed a better antimibrobian action in correlation with Ca(OH) and tergentol solutions. The statistical differences among clorhexydine and this study other solutions was not significant in a greater part of comparisons.CONCLUSIONS: The 0.12% clorhexydine digluconate was the most effective antibiotic agent in this research. Ca(OH) and tergentol solutions does not demonstrate satisfactory effectiveness in correlation the clorhexydine, mainly, for the Streptococcus mutans. More complete studies are necessary for CHD 20 evaluation as an oral antiseptic.

PMID: 16186970 [PubMed - in process]

Temperatures in soda lime during degradation of desflurane, isoflurane, and sevoflurane by desiccated soda lime.

Anesth Analg. 2005 Sep;101(3):753-7, table of contents

Authors: Laster MJ, Eger EI

Rarely, fire and patient injury result from the degradation of sevoflurane by desiccated Baralyme. The present investigation sought to determine whether high temperatures also arose with sevoflurane use in the presence of desiccated soda lime. We desiccated soda lime by directing a 10 L/min flow of oxygen through fresh absorbent. Using 1140 +/- 30 g (mean +/- sd) of this desiccated absorbent, we filled a single standard absorber canister placed in a standard anesthetic circuit to which we directed a 6 L/min flow of oxygen containing 1.5 minimum alveolar concentration (MAC) desflurane or sevoflurane, or 3.0 MAC desflurane, isoflurane, or sevoflurane (with and without concurrent delivery of 200 mL/min carbon dioxide). In an additional test, 2 canisters (rather than a single canister) containing desiccated absorbent were used and 3.0 MAC sevoflurane was applied. A 3-L reservoir bag served as a surrogate lung, and we ventilated this lung with a minute ventilation of 10 L/min. With desflurane at 1.5 MAC or 3.0 MAC or isoflurane at 3.0 MAC temperatures increased in 20 to 40 min to a peak of 30 degrees C to 45 degrees C and then declined. With 1.5 or 3.0 MAC sevoflurane, temperatures increased to approximately 90 degrees C, after which temperatures declined. Concurrent delivery of carbon dioxide and sevoflurane did not increase the peak temperatures reached. The use of 2 canisters increased the duration but not the peak of increased temperature reached with 3.0 MAC sevoflurane. No fires resulted from degradation of any anesthetic.

PMID: 16115987 [PubMed - indexed for MEDLINE]

Use of vitamin C in delayed tooth replantation.

Braz Dent J. 2005;16(1):17-22

Authors: Panzarini SR, Perri de Carvalho AC, Poi WR, Sonoda CK

This study evaluated microscopically the effects of root surface treatment with three different solutions in delayed rat teeth replantation. Central incisors from 30 rats (Rattus norvegicus, albinus Wistar) were extracted and left on a bench for 6 h. The pulps were extirpated and root canals were irrigated with 1% sodium hypochlorite. After endodontic treatment, the root surfaces of all teeth were submitted to a 10-min treatment with 1% sodium hypochlorite, changed every 5 min. The teeth were then rinsed with saline for 10 min and assigned to 3 groups with ten specimens each. Groups I, II and III were treated, respectively, with 2% acidulated-phosphate sodium fluoride, vitamin C solution and effervescent vitamin C (2 g, Redoxon. After root surface treatment, the teeth were filled with calcium hydroxide and replanted. The animals were sacrificed after 10 and 60 days. Group I (fluoride) presented the largest areas of replacement resorption and ankylosis. Comparing both vitamin C groups, Group III (effervescent vitamin C) yielded better results, showing more areas of ankylosis and replacement resorption than areas of inflammatory resorption.

PMID: 16113928 [PubMed - indexed for MEDLINE]

Influence of apical patency and filling material on healing process of dogs' teeth with vital pulp after root canal therapy.

Braz Dent J. 2005;16(1):9-16

Authors: Holland R, Sant'Anna J&#xFA;nior A, Souza V, Dezan Junior E, Otoboni Filho JA, Bernabé PF, Nery MJ, Murata SS

The purpose of this study was to investigate the periapical healing process of dogs' teeth with or without apical patency and after root canal filling with two types of sealers. Forty roots of premolars and incisors were utilized. The root canals were over-instrumented and dressed with a corticosteroid-antibiotic solution for 7 days to obtain ingrowth of periapical connective tissue into the canals. After this period, the tissue was removed in half of the specimens (groups with patency) and preserved in the other half (groups without patency). Canals were filled by lateral condensation technique with gutta-percha points and either a calcium hydroxide-based sealer (Sealer Plus) or a Grossman's cement (Fill Canal). The animals were killed by anesthetic overdose 60 days after the endodontic treatment and anatomic pieces were obtained and prepared for histologic examination. Data were evaluated in a blind analysis on the basis of several histomorphologic parameters. The groups without patency had better results (p=0.01) than those in which the ingrown connective tissue was removed. Comparing the sealers, Sealer Plus had significantly better results (p=0.01) than Fill Canal. In conclusion, both the apical patency (presence or absence) and the type of root canal filling material influenced the periapical healing process in dogs' teeth with vital pulp after root canal treatment. The use of a calcium hydroxide-based sealer in teeth without apical patency yielded the best results among the experimental conditions proposed.

PMID: 16113927 [PubMed - indexed for MEDLINE]

Facial cellulitis arising from dens evaginatus: a case report.

Kaohsiung J Med Sci. 2005 Jul;21(7):333-6

Authors: Chen CM, Lee KT, Chuang FH, Hong YY, Chen HC, Hsu KR, Wu YM, Lee HE

Dens evaginatus is a developmental anomaly that produces a tubercle on the occlusal surface of a tooth. It is found most frequently in the mandibular premolars. The occlusal tubercle easily causes occlusal interferences. Attrition or fracture of the tubercle can lead to pulpitis, pulp necrosis, periapical pathosis, and periapical infection. This case report illustrates the treatment of facial cellulitis arising from dens evaginatus with open apex. Calcium hydroxide was used for the apexification procedure. One year after canal obturation, radiography revealed no apical pathosis and the apical seal was evident.

PMID: 16089313 [PubMed - indexed for MEDLINE]

The influence of some dentin primers on calcium hydroxide lining cement.

J Contemp Dent Pract. 2005 May 15;6(2):1-9

Authors: El-Araby A, Al-Jabab A

Dentin primer is applied as a routine procedure prior to bonding to improve the sealing properties of direct polymerizing resins. Some primers contain acetone or alcohol that may affect the properties of calcium hydroxide liner which is placed as a direct or indirect pulp cap. If calcium hydroxide is softened or smeared over the cavity walls, the bonding will be impaired. Therefore, if this occurs, the cement must be removed, the walls must be cleansed, and the procedure must be repeated with careful application of dentin primer. OBJECTIVE: The purpose of this study was to determine the wear and compressive strength of a calcium hydroxide liner after exposure to different kinds of dentin primers for different periods of time. METHODS: The calcium hydroxide used in this study was Dycal. It was mixed according to the manufacturer's instructions and placed in plastic rings of 0.5 mm x 5 mm and allowed to set at 37 degrees C for 15 min under 500 gm load. To determine erosion, the height for each sample before and after application of primers was recorded using a Digital Height Measuring Instrument "Digmar" 817. Compressive strength specimens were also prepared. RESULTS: Calcium hydroxide treated with Optibond (alcohol based) or Syntac (acetone based) for 1 min or 5 min had the highest erosion values and the lowest compressive strength values. Gluma CPs (water based primer) had the least effect on calcium hydroxide values.

PMID: 15915199 [PubMed - indexed for MEDLINE]

Biological aspects of tooth fragment reattachment in immature incisors.

J Indian Soc Pedod Prev Dent. 2005 Mar;23(1):42-3

Authors: Kalra N, Rai P

Tooth fragment reattachment is a relatively new technique and there are many aspects which still need to be explored. Reported here is a case of enamel and dentin fracture of 11 and 21. There was a very thin layer of dentin clinically over the pulp chamber and the root apices were immature. The reattachment procedure was modified slightly. The initial joint was made with protective calcium hydroxide and glass ionomer cement on the approximating surfaces. The further reattachment was accomplished using composites and acid etch technique. This was done for pulpal protection. After six months, reattachment was intact and successful with no staining, sensitivity or pain. The radiographs revealed root completion of the immature incisors. The reattachment procedure proved to be biologically superior in addition to its esthetic value and psychological advantage.

PMID: 15858307 [PubMed - in process]

Remineralization of carious dentin. II: In vivo microradiographic and chemical studies in human permanent teeth capped with calcium hydroxide.

Braz Dent J. 2004;15(3):186-9

Authors: Conrado CA

The main aim of this in vivo study was to evaluate a possible remineralization of human carious dentin by means of chemical and microradiographic studies. Eighty-six samples of carious dentin were removed from 36 permanent teeth of 24 patients. These were divided into untreated (control) and chemically pure calcium hydroxide-capped (experimental) samples and analyzed at intervals varying from 10 to 120 days. They were classified according to depth of caries and degree of dentin softening and evaluated in relation to weight, phosphorus concentration, qualitative and quantitative microradiography and absolute values of total mineral content. One of two halves of each sample was selected for chemical studies and the other for total content of mineral salts. Experimental samples were examined with a light microscope and the results obtained showed a qualitative increase in radiopacity. Quantitatively, it was observed that, in the case of samples analyzed for phosphorus concentration, the average mean of differences in percentage increase after treatment was 9.6%, while for the samples evaluated microradiographically for total mineral content, it was 22.29%. In both cases, the differences were statistically significant.

PMID: 15798820 [PubMed - in process]

Antimicrobial potential of medicaments used in healing process in dogs' teeth with apical periodontitis.

Braz Dent J. 2004;15(3):181-5

Authors: Estrela C, Holland R, Bernab&#xE9; PF, Souza V, Estrela CR

The objective of this study was to evaluate the influence of irrigants on the antimicrobial potential of calcium hydroxide paste in dogs' teeth with apical periodontitis. Forty-eight premolar teeth of adult mongrel dogs had their root canals opened to the oral environment for 6 months. The root canals were prepared and treated with different irrigating solutions and intracanal medicaments, according to the following groups: 1) 2.5% sodium hypochlorite (NaOCl) + calcium hydroxide paste (CHP); 2) 2% chlorhexidine (CHX) + CHP; 3) vinegar + CHP; 4) vinegar + vinegar. In group 4, both the irrigating solution and intracanal medicament were vinegar, which was renewed every 7 days. Each sample was collected by using two paper points maintained in position for 1 min, and individually transported and immersed in 7 mL of Letheen broth (LB), followed by incubation at 37 masculineC for 48 h. Microbial growth was analyzed by two methods: turbidity of the culture medium and subculture on a specific nutrient broth (brain heart infusion). After 21 days, all experimental groups had microbial growth, however, in different percentages: group 1 - 30%; group 2 - 30%; group 3 - 40%; group 4 - 60%. All materials tested had antimicrobial potential; however, the influence of calcium hydroxide paste on the control of microorganisms must be remembered.

PMID: 15798819 [PubMed - in process]

The pH changes of four different root canal sealers after mixing at various time intervals in vitro.

J Contemp Dent Pract. 2004 Nov 15;5(4):71-8

Authors: Evcil MS, Colak M

The purpose of this study was to compare the surface pH level of four different type sealers after mixing at various time intervals in vitro. After cleaning and shaping root canals in 50 recently extracted, single-rooted human teeth, they were divided into six groups. Each of four groups was obturated with Apexit, N2, Sealapex, and Grossman sealers. The remaining groups served as controls. In group 1 nothing was added to the vial of saline solution. In group 2 canals had been instrumented but not obturated with sealer. The pH level of saline solutions was determined at intervals of 1 hour, 4 hours, 1 day, 2 days, 3 days, 1 week, and 4 weeks after teeth were placed in them. The pH levels of the five solutions were compared to each other and to that of saline solution only.

PMID: 15558092 [PubMed - indexed for MEDLINE]

[Root canal therapy opportunity in replanted teeth due to injury.]

Shanghai Kou Qiang Yi Xue. 2004 Oct;13(5):457-8

Authors: Zhang QY, Wang XL, Huang LJ

PURPOSE: To investigate the opportunity of different root canal therapies in replantation of tooth due to injury. METHODS: 49 cases with teeth luxation were randomly divided into three groups. In group A, the pulp was removed before replanted, and calcium hydroxide was filled in root canals and condensated routinely after half a year. In group B, the pulp was removed one week after being replanted. In group C, the pulp was removed until pulp disease. RESULTS: The effect of group A(81.25%) and B (94.44%) was better than group C (53.33%), P<0.05. And the effect of group A and B was similar. CONCLUSION: It's an ideal method to replant luxated tooth within 3 hours with removal of pulp tissue, root canal filling with calcium hydroxide one week after replantation of tooth and condensated routine root canal therapy after half a year.

PMID: 15514883 [PubMed - in process]

Epidemiology of betel quid usage.

Ann Acad Med Singapore. 2004 Jul;33(4 Suppl):31-6

Authors: Gupta PC, Ray CS

Betel quid chewing is an ancient practice common in many countries of Asia and among migrated communities in Africa, Europe and North America. It enjoys complete social acceptance in many societies and is also popular among women. In its most basic form, betel quid consists of betel leaf (Piper betel), areca nut, the main psychoactive ingredient, and slaked lime (calcium hydroxide). Areca nut is said to be the fourth most commonly used psychoactive substance in the world, after caffeine, nicotine and alcohol. There are a great variety of ingredients and ways of preparing betel quid in different countries. In some, particularly in India, tobacco is added to the quid. In recent years, commercially-manufactured non-perishable forms of betel quid (pan masala or betel quid mixtures and gutka), not containing betel leaf, have been marketed. Within a short period of about 2 decades, this industry has risen in value to several hundred US million dollars. Use of areca nut in any form is not safe for oral health; the use of commercially manufactured forms seems even riskier.

PMID: 15389304 [PubMed - indexed for MEDLINE]

Fires from the interaction of anesthetics with desiccated absorbent.

Anesth Analg. 2004 Sep;99(3):769-74, table of contents

Authors: Laster M, Roth P, Eger EI

Rarely, fire and patient injury have resulted from the degradation of sevoflurane by desiccated carbon dioxide absorbent. Desiccated absorbent also can degrade desflurane and isoflurane, and in the present investigation we sought to determine whether a danger of fire also arose with their use in the presence of desiccated absorbent. Baralyme was desiccated by heating and directing a 10 L/min flow of oxygen through the absorbent. Approximately 1200 g of this desiccated absorbent was used to fill a standard absorber placed in a standard anesthetic circuit to which we directed a 6 L/min flow of oxygen containing 1.5 or 3.0 MAC desflurane, isoflurane, or sevoflurane. A 3-L reservoir bag served as a surrogate lung, and we ventilated this lung with a minute ventilation of 10 L/min. With desflurane or isoflurane, at both 1.5 MAC and 3.0 MAC, temperatures increased in 30 to 70 min to a peak of approximately 100 degrees C and then decreased. With 1.5 MAC sevoflurane (3.0 MAC was not studied), temperatures increased to over 200 degrees C, and in 2 of 5 studies, flames appeared in the anesthetic circuit. In a separate study, we found that concurrent delivery of carbon dioxide and desflurane did not increase peak temperatures. We conclude that the interaction of desflurane or isoflurane with desiccated absorbent is not likely to produce the conflagrations possible with sevoflurane.

PMID: 15333409 [PubMed - indexed for MEDLINE]

Remineralization of carious dentin. I: In vitro microradiographic study in human teeth capped with calcium hydroxide.

Braz Dent J. 2004;15(1):59-62

Authors: Conrado CA

The objective of this in vitro study was to evaluate a possible remineralization of human carious dentin by calcium hydroxide. Thirty-nine freshly extracted human permanent and deciduous carious teeth were split into two halves. One half was used as control and the other as experimental. In the latter, a cavity was prepared and the remaining bottom layer of demineralized dentin capped with chemically pure calcium hydroxide. The experimental samples were stored at 37 masculine C. Time intervals were 2, 4, 6, 8, 10 and 12 weeks. All tooth halves were sawed and ground to plano-parallel sections with a thickness varying from 75 to 117 micro m. Qualitative microradiographs showed a qualitative increase in radiopacity of the calcium hydroxide treated samples. Quantitative microradiography showed a statistically significant increase in total mineral content in the experimental samples compared to the control samples. These results indicate an in vitro remineralization of carious dentin by calcium hydroxide.

PMID: 15322647 [PubMed - in process]

Apical seal of root canals with gutta-percha points with calcium hydroxide.

Braz Dent J. 2004;15(1):26-9

Authors: Holland R, Murata SS, Barbosa HG, Garlipp O, Souza Vd V, Dezan Junior E

The objective of this research was to determine if gutta-percha points with calcium hydroxide [Ca(OH)2] improve the apical seal after root canal filling and if the master point does it alone. Human single recently extracted teeth were biomechanically prepared and the root canals filled by the lateral condensation technique with ZOE and gutta-percha points, with or without calcium hydroxide. The teeth were placed into a 2% methylene blue solution in a vacuum environment for 24 h after which they were processed for stereomicroscope evaluation. Better results were observed with the teeth filled with gutta-percha points with calcium hydroxide (p=0.01). We conclude that these new points make a better apical seal and that these results can also be obtained with the calcium hydroxide master point associated with regular ones (p=0.05).

PMID: 15322641 [PubMed - in process]

Influence of different vehicles on the pH of calcium hydroxide pastes.

J Oral Sci. 2004 Jun;46(2):107-11

Authors: Pacios MG, de la Casa ML, de Bulacio MA, L&#xF3;pez ME

The main known benefit of calcium hydroxide as an intracanal medicament lies in the bactericidal effect conferred by its pH. The objective of this work was to determine the influence of the vehicle on the pH of calcium hydroxide pastes after usage in patients and in vitro. The incisor root canals of 180 patients were instrumented and filled with calcium hydroxide pastes containing distilled water, chlorhexidine, propylene glycol, anesthetic solution, camphorated p-monochlorophenol and camphorated p-monochlorophenol-propylene glycol. The pH of the paste in the patients' root canals was measured at 7, 14 and 21 days. Similarly, pH was measured in vitro up to 21 days. The pH of all the pastes remained constant throughout the time periods assessed. The calcium hydroxide-water combination showed significantly higher pH values than the other pastes in clinical use. Comparative analysis showed that the pH values of the anesthetic solution, camphorated p-monochlorophenol and camphorated p-monochlorophenol-propylene glycol were significantly higher in vitro. The type of vehicle was shown to influence the final pH of the pastes. However, the alkalinity of all pastes was maintained over time under the experimental conditions.

PMID: 15287544 [PubMed - indexed for MEDLINE]

Nanocrystalline tetracalcium phosphate cement.

J Dent Res. 2004 May;83(5):425-8

Authors: Gbureck U, Barralet JE, Hofmann MP, Thulí R

Calcium hydroxide cements can lack long-term stability and achieve sustained release by matrix-controlled diffusion of hydroxyl ions. Tetracalcium phosphate (TTCP) hydrolyzes slowly to form calcium hydroxide and a thin insoluble apatite layer that prevents further reaction. In this study, mechanical amorphization was used to create a setting calcium-hydroxide-releasing cement from TTCP. The effect of high-energy ball milling of TTCP on the mechanical properties of the cement was investigated. X-ray diffraction data were used to determine the phase composition of the set cements. An accelerated in vitro test compared pH of water after prolonged boiling of nanocrystalline TTCP cements and a calcium salicylate material. As milling time increased, cement compressive strength and degree of conversion increased. Hydroxyl ion release from the cement was comparable with that from a calcium salicylate material. This new cement system offers the antimicrobial potential of calcium salicylate materials combined with the long-term stability of insoluble apatite cements.

PMID: 15111637 [PubMed - indexed for MEDLINE]

Inferior alveolar nerve paresthesia relieved by microscopic endodontic treatment.

Bull Tokyo Dent Coll. 2003 Nov;44(4):209-12

Authors: Yatsuhashi T, Nakagawa K, Matsumoto M, Kasahara M, Igarashi T, Ichinohe T, Kaneko Y

We experienced two cases of inferior alveolar nerve paresthesia caused by root canal medicaments, which were successfully relieved by microscopic endodontic treatment. In the first case, the paresthesia might have been attributable to infiltration of calcium hydroxide into the mandibular canal through the root canals of the mandibular left second molar tooth. In the second case, the paresthesia might have been attributable to infiltration of paraformaldehyde through the root canals of the mandibular right second molar tooth. The paresthesia was relieved in both cases by repetitive microscopic endodontic irrigation using physiological saline solution in combination with oral vitamin B12 and adenosine triphosphate.

PMID: 15103918 [PubMed - indexed for MEDLINE]

Control of microorganisms in vitro by endodontic irrigants.

Braz Dent J. 2003;14(3):187-92

Authors: Estrela CR, Estrela C, Reis C, Bammann LL, P&#xE9;cora JD

The aim of this study was to determine the minimum inhibitory concentration (MIC) and antimicrobial effectiveness by the direct exposure test of 4 endodontic irrigants [1% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), 1% calcium hydroxide (Ca(OH)2; prepared with 1 g of Ca(OH)2 and 100 mL of sterile distilled water), a solution of Ca(OH)2 + detergent (HCT20)] for S. aureus, E. faecalis, P. aeruginosa, B. subtilis, C. albicans and a mixed culture. Microbial growth was analyzed by two methods: turbidity of the culture medium that was confirmed by Gram stain and subculture in a specific nutrient broth. In the dilution test, NaOCl solution showed MIC equal to 0.1% for S. aureus, E. faecalis, P. aeruginosa and C. albicans and equal to 1% for B. subtilis and the mixed culture. CHX (2%) presented MIC equal to 0.000002% for S. aureus, 0.02% for E. faecalis, B. subtilis, C. albicans and the mixed culture and 0.002% for P. aeruginosa. Ca(OH)2 solution (1%) showed MIC greater than 1% for all the microorganisms except P. aeruginosa for which it was equal to 1%. Calcium hydroxide solution + detergent showed MIC equal to 4.5 mL for S. aureus, P. aeruginosa, B. subtilis, C. albicans and the mixed culture and greater than 4.5 mL for E. faecalis. In the direct exposure test, NaOCl had better antimicrobial effectiveness for all microorganisms at all times. CHX (2%) was effective for S. aureus, E. faecalis and C. albicans at all times, and ineffective for P. aeruginosa, B. subtilis and the mixed culture. The other solutions showed the worst results.

PMID: 15057395 [PubMed - in process]

[Analysis of the influence of Ca(OH)2 and HA on cell cycle of pulp cells by flow cytometry]

Shanghai Kou Qiang Yi Xue. 2001 Mar;10(1):52-3

Authors: Zhang JN, Wang XY

OBJECTIVE: The influence of Ca(OH)(2) (calcium hydroxide) and HA(hydroxyapatite) as pulp capping agents on cell cycle of pulp cells was analyzed by flow cytometry. METHODS:Permanent teeth pulps of pigs were capped with Ca(OH)(2), and HA following mechanical pulp exposure. The teeth were extracted after 2, 4, 8 and 12 weeks, respectively. The pulps were taken and digested by collagenase. The percentages of pulp cells in G0/G1, G2, S and M periods were determined by flow cytometry and computer analysis. RESULTS: The percentage of cells in G0/G1, period was decreased, whereas the percentage of cells in S period was increased after pulp capping with Ca(OH)(2) and HA. CONCLUSION: This study indicated that Ca(OH)(2) and HA could increase DNA synthesis of pulp cells.

PMID: 14994080 [PubMed]

[The comparison of performance between calcium hydroxide and metapex root canal filling materials in apexification of young permanent teeth]

Shanghai Kou Qiang Yi Xue. 2002 Dec;11(4):382-4

Authors: Wang S

PMID: 14983390 [PubMed]

[Clinical evaluation of zinc oxide eugenol and Vitapex as root canal filling materials in primary teeth]

Shanghai Kou Qiang Yi Xue. 2003 Oct;12(5):377-9

Authors: Zhang XF, Xu XB

PMID: 14966617 [PubMed - indexed for MEDLINE]

CELLS AND EXTRACELLULAR MATRICES OF DENTIN AND PULP: A BIOLOGICAL BASIS FOR REPAIR AND TISSUE ENGINEERING.

Crit Rev Oral Biol Med. 2004;15(1):13-27

Authors: Goldberg M, Smith AJ

Odontoblasts produce most of the extracellular matrix (ECM) components found in dentin and implicated in dentin mineralization. Major differences in the pulp ECM explain why pulp is normally a non-mineralized tissue. In vitro or in vivo, some dentin ECM molecules act as crystal nucleators and contribute to crystal growth, whereas others are mineralization inhibitors. After treatment of caries lesions of moderate progression, odontoblasts and cells from the sub-odontoblastic H&#xF6;hl's layer are implicated in the formation of reactionary dentin. Healing of deeper lesions in contact with the pulp results in the formation of reparative dentin by pulp cells. The response to direct pulp-capping with materials such as calcium hydroxide is the formation of a dentinal bridge, resulting from the recruitment and proliferation of undifferentiated cells, which may be either stem cells or dedifferentiated and transdifferentiated mature cells. Once differentiated, the cells synthesize a matrix that undergoes mineralization. Animal models have been used to test the capacity of potentially bioactive molecules to promote pulp repair following their implantation into the pulp. ECM molecules induce either the formation of dentinal bridges or large areas of mineralization in the coronal pulp. They may also stimulate the total closure of the pulp in the root canal. In conclusion, some molecules found in dentin extracellular matrix may have potential in dental therapy as bioactive agents for pulp repair or tissue engineering.

PMID: 14761897 [PubMed - as supplied by publisher]

Self-limiting supplements fed to cattle grazing native mixed-grass prairie in the northern Great Plains.

J Anim Sci. 2004 Jan;82(1):298-306

Authors: Schauer CS, Lardy GP, Slanger WD, Bauer ML, Sedivec KK

Objectives of this research were to compare animal performance with or without supplementation, compare effectiveness of three intake limiters, and to examine seasonal changes in nutritive value of native range in south-central North Dakota. Treatments included 1) control (CONT; no supplement); 2) hand-fed (HF) supplement, with no chemical limiter; 3) 16% salt (NACL); 4) 5.25% ammonium chloride and ammonium sulfate (AS); and 5) 7% calcium hydroxide (CAOH). Supplements were based on wheat middlings, barley malt sprouts, and soybean hulls and were formulated to provide 40% of the CP intake and 32% of the NEm intake of 350-kg steers. Trials 1 and 2 each used 70 yearling steers (370.8 +/- 0.04 and 327.9 +/- 0.76 kg initial BW for Trials 1 and 2, respectively). In each year, four 28-d periods from the latter half of June through mid-October were used. Steers were stratified by weight and allotted randomly to treatments in 1 of 10 16-ha pastures (two pastures per treatment for each trial). In Trial 1, diet sampling began in the first 28-d period, but supplementation did not begin until the second 28-d period. In Trial 2, supplementation and diet collection began in the first 28-d period. Cation-anion differences (DCAD; Na + K - Cl - S) for NACL, AS, CAOH, and HF supplements were 151, -735, 160, and 166 mEq/ kg, respectively. In Trial 1, no treatment, period, or treatment x period effects for supplement intake were detected (P > or = 0.29). In Trial 2, a treatment x period interaction for supplement intake occurred (P = 0.005) because HF steers were offered a constant amount of supplement daily, whereas steers fed AS, CAOH, and NACL were allowed to consume ad libitum quantities of supplement. Average daily gain in Trial 1 was not affected (P = 0.21) by supplementation. In Trial 2, NACL, AS, and HF treatments had higher (P < or = 0.07) ADG than CONT. In Trial 1, final weights were not affected by supplementation (P = 0.23). In Trial 2, final weights of NACL- and HF-fed steers were greater than for CONT and CAOH steers (P < 0.10). In Trial 2, CONT steer final weights were lower than all supplemented treatments (P < 0.10). For yearling steers grazing native range, use of NACL as a limiter resulted in increased weight gains compared with using either CAOH or AS; however, no limiter that was tested restricted supplement intake as effectively as HF. More research is necessary to determine the optimum limiter level and the effect of forage quality on supplement intake.

PMID: 14753374 [PubMed - indexed for MEDLINE]

Heavy-metal pollution and its state in algae in Kakehashi river and Godani river at the foot of Ogoya mine, Ishikawa Prefecture.

Anal Sci. 2004 Jan;20(1):73-8

Authors: Nakanishi Y, Sumita M, Yumita K, Yamada T, Honjo T

Alga as Achnanthes minutissima among diatoms is a widely adaptable taxon on the state of an aquatic environment. In this study, it was found that diatom had a specific tolerance to heavy metals (Cu, Zn, Pb, and Cd etc.) in river water samples, because the diatom assemblage consisted of almost only Achnanthes minutissima in Kakehashi river and Godani river, which were polluted with waste water from Ogoya copper mine. The relationship between the concentrations of heavy metals (Cu, Zn, Pb and Cd) in river water and the attached substances (algae and silt etc.) and the relative abundances of diatom taxa were investigated in detail. The results indicated that the higher is the concentration of heavy metals in the river environment, the higher is only the relative abundances of Achnanthes minutissima. Thus, the taxon can be used as a bioindicator of heavy metal pollution. The relative rates of toxic chemical forms of copper in algae were 61 - 92% in the attached substances and 49-70% in the sediment on the river bed, respectively. Therefore, it was found that diatom as Achnanthes minutissima had a tolerance to heavy metals in river water, being able to live in such an environment. Since the water treated with calcium hydroxide from the deposition reservoir of Ogoya mine enters in Godani river, the river is polluted by heavy metals (Cu, Zn, Pb and Cd etc.). From the viewpoint of both biological and chemical analyses, Godani river is still polluted with heavy metals, because their concentrations in the river samples were very high. On the other hand, in Kakehashi river, the concentrations of heavy metals were very low and the distributions of some diatoms appeared in an unpolluted Nishimata river were observed. Therefore, Kakehashi river seems to be considerably recovered from heavy-metal pollution after closing the Ogoya mine.

PMID: 14753260 [PubMed - indexed for MEDLINE]

[Clinical studies of calcium hydroxide disinfecting infectious root canal of deciduous tooth]

Shanghai Kou Qiang Yi Xue. 2003 Apr;12(2):109-11

Authors: Zhao J, Li SH, Zhu ZH

OBJECTIVE: To search for a more ideal way to disinfect infectious root canal of deciduous tooth. METHODS: According to bacterial occurrence and clinical effect, 40 cases of infectious root canal of deciduous teeth disinfected with Ca(OH)2 were investigated, the other 40 cases with traditional way of using FC and CP respectively, were used as the control. RESULTS: Fist of all, the bacteria of deciduous tooth infectious root canal were same as the bacteria of permanent tooth infectious root canal. Secondly, Ca(OH)2 was stronger in disinfecting deciduous tooth infectious root canal. Thirdly, so far as sterilization was concerned, Ca(OH)2 had the same disinfectant as FC, and was better than CP, but FC had some irritation and poisonous side-effects to periodical tissue. So Ca(OH)2 was safe and effective for deciduous tooth infectious root canal. CONCLUSION: It was a more ideal way to disinfect deciduous tooth infectious root canal by Ca(OH)2.

PMID: 14661514 [PubMed - indexed for MEDLINE]