EVIDENCE-PRACTICE GAP IN TREATMENT DECISIONS ABOUT DEFECTIVE COMPOSITE AND AMALGAM RESTORATIONS AMONG BRAZILIAN DENTISTS.

Better understanding of dentists' decision-making about defective restorations is needed to close the evidence-practice gap (EPG). Aim: this study aimed to quantify the EPG about defective restorations and identify dentist factors associated with this EPG. Methods: 216 dentists from São Paulo State, Brazil, completed a questionnaire about three clinical case scenarios involving defective composite restorations with cementum-dentin margins (case 1) and enamel margins (case 2), and an amalgam (case 3) restoration. Dentists were asked what treatment, if any, they would recommend, including preventive treatment, polishing, re-surfacing, or repairing the restoration, or replacing the entire restoration. Replacing the entire restoration in any of these three scenarios was classified as inconsistent with the evidence, comprising an EPG. Bivariate analyses using Chi-square, ANOVA, or multiple comparison tests were performed (p<.05). Results: for defective composite restorations, 49% and 55% of dentists chose to replace the entire restoration for cases 1 and 2, respectively. Twenty-nine percent of dentists chose to replace the entire amalgam restoration. Dentists were significantly more likely to choose to replace the defective amalgam restoration than the composite restoration with a defect at the cementum-dentin margins or the enamel margins (both at p < .001). Female dentists were more likely to choose a conservative treatment than male dentists for cases 1 (p=.034) and 2 (p=.009). Dentists with a higher percentage of patients interested in individualized caries prevention were also more conservative in case 1 (p=.045). Conclusion: a substantial EPG regarding treatment decisions for defective restorations exists, especially for composite restorations. This study adds to the international evidence that an EPG exists in this clinical area and that global strategies need to be developed to close the gap.

METHODS FOR CARIES PREVENTION IN ADULTS AMONG DENTISTS FROM A BRAZILIAN COMMUNITY: Adult' caries prevention among Brazilian dentists.

Little is known about dental practice patterns of caries prevention in adults among Brazilian dentists. OBJECTIVE: To quantify procedures used for caries prevention for adult patients among dentists from a Brazilian community. METHODS: Dentists (n=197) who reported that at least 10% of their patients are more than 18 years old participated in the first Brazilian study that used a translated version of the "Assessment of Caries Diagnosis and Caries Treatment" from the U.S. National Dental Practice-Based Research Network. A questionnaire about characteristics of their practice and patient population were also completed by the dentists. Generalized linear regression models and a hierarchal clustering procedure were used (p<0.05). RESULTS: In-office fluoride application was the preventive method most often reported. The main predictors for recommending some preventive agent were: female dentist (dental sealant; in-office fluoride; non-prescription fluoride) and percentage of patients interested in caries prevention (dental sealant; in-office fluoride; non-prescription fluoride). Other predictors included private practice (dental sealant), percentage of patients 65 years or older (in-office fluoride), graduation from a private dental school (non-prescription fluoride), years since dental school graduation (chlorhexidine rinse) and using a preventive method (recommending sealant/fluoride/chlorhexidine rinse/sugarless, xylitol gum). Cluster analysis showed that dentists in the largest subgroup seldom used any of the preventive agents. CONCLUSION: Dentists most often reported in-office fluoride as a method for caries prevention in adults. Some practitioner, practice and patients' characteristics were positively associated with more-frequent use of a preventive agent.

New methodology to evaluate bond strength of root-end filling materials.

This study evaluated the bond strength of root-end filling materials to root-end cavities using a new methodology. Twenty maxillary central incisors were subjected to biomechanical preparation (#80 hand file) and sectioned transversally 2 mm short of the apex and 4 mm coronally to this point. The root cylinders were embedded in acrylic resin and positioned at 45° to the horizontal plane for preparation of root-end cavities with a diamond ultrasonic retrotip. Two groups (n=10) were formed according to the root-end filling material: MTA and Super EBA. A gutta-percha cone (#80) was tug-backed at the limit between the canal and the root-end cavity. The cavity was filled and the gutta-percha cone was removed after complete setting of the sealer. The specimens were placed in an Instron machine with the root-end filling turned downwards. The push-out shaft was inserted in the space previously occupied by the gutta-percha cone and run at a crosshead speed of 1.0 mm/min for pushing out the root-end filling material. Data were analyzed by ANOVA (α=5%). Super EBA (6.03±1.31) presented higher bond strength (MPa) than MTA (1.81±0.45) (p>0.05). There was a predominance of cohesive failures for Super EBA and mixed for MTA. The protocol of specimen preparation is effective and introduces a specific methodology for assessing bond strength of root-end filling materials to dentin. Among the materials, Super EBA presented the highest bond strength.

Three-dimensional finite element analysis of endodontically treated teeth with weakened radicular walls restored with different protocols.

STATEMENT OF PROBLEM: The restoration of weakened roots with glass fiber posts (GFPs) remains a challenge. PURPOSE: The purpose of this study was to evaluate the stress distribution of endodontically treated teeth with weakened radicular walls restored with different protocols by 3-dimensional finite element analysis (3D-FEA). MATERIAL AND METHODS: The following 4 models of endodontically treated maxillary canines restored with metal ceramic crowns were simulated on the basis of computed microtomographic images to characterize the groups: GNW (control), a nonweakened root restored with a GFP; GW, a weakened root restored with a GFP; GDA, a weakened root restored with a direct anatomic GFP; and GIA, a weakened root restored with an indirect anatomic GFP. Loads of 180 N were applied to the lingual surface on the incisal third of the teeth at 45 degrees. The models were supported by a periodontal ligament and fixed in 3 axes (x=y=z=0). The von Mises stress (VMS) was calculated. RESULTS: All models exhibited VMS concentrations at the loading area and were distributed along the proximal surfaces of the root. The GFP exhibited a homogeneous stress distribution, and similar VMS distributions were observed in all of the reconstructive techniques. CONCLUSIONS: Similar stress distributions were observed in the endodontically treated teeth, regardless of root weakness and the reconstructive technique for the radicular walls.

Occlusal caries prevention in high and low risk schoolchildren. A clinical trial.

PURPOSE: To evaluate the caries-preventive effect of a resin-modified glass-ionomer cement used as occlusal sealant (Vitremer) compared with fluoride varnish (Duraphat) application on occlusal surfaces of permanent first molars (OSPFM) in 6-8 year-old schoolchildren (n=268) at high (HR) and low (LR) caries risk. METHODS: The children were followed-up for 24 months after being systematically allocated into six groups as follows: Control Groups HRC and LRC: children receiving oral health education (OHE) every 3 months; Groups HRV and LRV: children receiving OHE plus varnish application biannually; and Groups HRS and LRS: children receiving OHE plus a single sealant application . The baseline and follow-up examinations were performed by the same calibrated dentist under natural light, using CPI probes and mirrors, after toothbrushing and air-drying. The DMFS was used to record dental caries, in addition to the detection of initial lesions (IL). Data analysis was performed with two primary outcome measures: DMF and DMF+ IL on the OSPFM. RESULTS: After 24 months, only the HRS group showed statistically lower DMF and DMF+IL increments on OSPFM compared with HRC group. HRV group did not differ from HRC and HRS groups. For LR groups, no statistical difference (P> 0.05) was observed among the treatments.