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AIM: The aim of this study was to verify two different types of interfaces in Morse taper connection implants, relating the mechanical resistance to a loosening torque that is required to separate or move the prosthetic abutment. MATERIAL AND METHODS: Ten Morse taper connection implants and their respective abutments were divided into two groups (n = 5), DH (double hexagon) interface and OI (octagonal implant) interface. A standard insertion of implants was performed in a stainless steel base, where each abutment received a sequence of two consecutive tightening torques at a 10-minute interval, followed by a loosening torque, which was measured using a digital torque gauge. The Student’s t-test with a 5% significance level was used for data analysis. RESULTS: The results showed a statistically significant difference in the loosening torque values compared with DH torque values (p < 0.05). However, the difference between tightening and loosening torque values was not statistically significant in the OI group (p = 0.465). CONCLUSION: The study concluded that there was a difference in the torque required to loosen the abutment screws between the DH group and the OI group, with the latter showing better results.

The aim of this study was to evaluate the bond strength between composite resin and dentin using different bond systems. Sixteen human molars extracted were selected. Each tooth was vertically cut in 3 dentin fragments of 2 mm of thickness (n=42) and randomly divided among the groups. Groups 1 was used Adper Single Bond 2, for groups 2 Silorano primer, groups 3 Adper SE Plus, and 4 Scotchbond Multiuse. Two composite resin cylinders were built up on each dentin surface (n=10) and subjected to a micro shear bond strength test until failure. To evaluated the results were used the Kruskal-Wallis OneWay Analysis of Variance and Tukey Test (p=0.05). Kruskal-Wallis test evidenced at least one statistical significant difference (p=0.001). The Tukey test showed statistical significant differences among the group (P

Mechanical stability of implant-abutment set is fundamentally important for the success in implant supported rehabilitation. For this, the knowledge about torque removal values is essential. In this way, the objective of this work was to evaluate the torque reverse values in indexed abutments of Morse Taper system. Five Morse taper implants with their respective abutments were tested (n=5). Each abutment received a sequence of two consecutive torques in insertion (15Ncm) with an interval of ten minutes, and one reverse torque, all measured by digital torque wrench. The t-student test with 5% significance was used to evaluate the data. The analysis of results showed there is statistical significant difference in reverse torque values between the insertion torque value and reverse torque value intra-group, the indexed abutments presented an average percentage of torque loosing of 15% (P=0.002). It is possible to conclude that the use of indexed abutments of Morse taper system presented statistical significant reduction of reverse torque values, which in turns increase the risk of no biomechanical instability.