Ivo Contin

Measurement of buccal bone volume of dental implants by means of cone-beam computed tomography

PURPOSE The aim of this study was to evaluate the accuracy of cone-beam computed tomography (CBCT) for measuring the buccal bone volume around dental implants. MATERIALS AND METHODS Three to six implants were inserted into the anterior maxilla of eight skulls, depending on the availability of bone, and after this, the CBCT was performed. By means of CBCT image, measurements of the bone wall at three points of the implant were obtained, analyzed and compared with those obtained in the plaster skull casting. RESULTS The results showed that for the three points of the implants, no statistically significant difference in the measurements was obtained from the plaster model and CBCT images. CONCLUSIONS CBCT can be a useful tool for assessing buccal bone volume along the implant.

Resistência à fratura de restaurações diretas com cobertura de cúspide em pré-molares superiores endodonticamente tratados

Endodontically treated teeth are considered more susceptible to fracture because of the loss of tooth structure. The aim of this study was to evaluate the increase of resistance to fracture of upper bicuspids that underwent endodontic access and were restored with composite resin, with cuspal coverage. Forty extracted human maxillary premolars were divided in 4 groups: I--intact teeth; II--teeth with endodontic access and MOD preparation, restored with composite resin, without cuspal coverage; III--teeth with endodontic access, MOD preparation and occlusal reduction, restored with composite resin, with cuspal coverage; IV--teeth with endodontic access and MOD preparation, without any restoration. The test specimens were submitted to compression test up to their fracture. The test of Turkey and the ANOVA analysis were used to compare and test the results. The teeth from group III (with cuspal coverage) presented with significantly greater resistance to fracture, when compared with those from groups II (restored without cuspal coverage) and IV (not restored). The composite restoration with cuspal coverage can be considered an alternative for endodontically treated premolars.