Faculty Bibliography

INTRODUCTION: Disinfection of dentin surfaces is desirable so long as it does not interfere with subsequent bonding of adhesive resins. OBJECTIVE: To test the null hypothesis that bond strengths to dentin are not affected by previous application of an iodine disinfecting solution. MATERIALS AND METHODS: Twenty-four extracted non-carious molars were selected. Occlusal enamel was removed producing a flat dentin substrate. Test teeth were all treated with 2% Iodine disclosing/disinfecting solution (I(2)DDS) for 20 sec and rinsed for 20 sec followed by the application of self- or total- etching bonding systems, generating five adhesive groups (n=3): Single Bond; Prime & Bond NT; Clearfil SE Bond; Opti-Bond Plus. The control groups (n=3 per adhesive) had no disclosing/disinfectant application prior to adhesive application. A 4-mm thick resin restoration was built up on each tooth for microtensile testing. Statistical analyses between experimental and control groups were performed by student's t-test (alpha= 0.05). RESULTS: In general, experimental groups (previously treated with I(2)DDS) showed significantly lower bond strength values when compared with their respective controls (p<0.05), except for group Prime & Bond I(2) that did not significantly differ from its control (p>0.05). CONCLUSION: Acetone-base adhesive systems seem not to be affected by the application of I(2)DDS prior to etching and bonding procedures.

Thin-film bioceramic coatings are potential alternatives to overcome the limitations provided by other commercially available coating techniques like PSHA, where variable bioceramic dissolution added to a metalloceramic weak link are process- inherent. The purpose of this investigation was to determine the overall and site specific (to 0.5 mm from implant surface) levels of osseoactivity around a thin-film (IBAD processed) coated titanium alloy implant versus a non surface modified (sand-blasted/acid etched) titanium alloy implant in a canine model. The surgical model comprised the proximal tibiae epiphyses with four implants placed in each limb remaining for 2 and 4 weeks in-vivo. 10 mg/Kg oxytetracycline was administered 48 hours prior to euthanization. The limbs were retrieved by sharp dissection, reduced to blocks, and subsequently nondecalcified processed for fluorescent microscopy. Micrographs (20x mag) were acquired around the implant perimeter and merged for overall biological response evaluations, and four micrographs (40x mag. subdivided in rectangles) were acquired along one of the implant sides for tetracycline labeled area fraction quantification. The results showed biocompatible and osseoconductive properties for the thin-film coated and uncoated titanium alloy implants. Tetracycline labeled area fraction analyses showed that the thin-film coated implants presented significantly higher overall and site specific osseoactivity levels at 2 and 4 weeks. The site specific osseoactivity values were significantly higher compared to overall values for control and thin-film coated implants at both times in-vivo. According to the results obtained in this study, thin-film coated implants enhanced biological response at the early implantation times evaluated.