Evaluation of the effectiveness of a sealing gel in the sealing of the abutment / implant interface and in the maintenance of the preload of the retaining screws

Author(s)

Camila Berbel Seloto

• Document type: Master's Dissertation
• Press: Araçatuba. 2017-08-23.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araçatuba
• Defense date: 2017-06-29
• Advisor: Wirley Gonçalves Assunção

Abstract

This study evaluated the effectiveness of a sealing material in preload maintaining of retaining screws and the misfit on implant / abutment interface after mechanical cycling. It was formed six groups (n=12), being one test group (T) and other control group (C) for each type of abutment / implant connection (external hexagonal connection (EH) and UCLA abutments, Morse taper (MT) and UCLA abutments, and CM connection and flexcone (CF) abutments). In the test groups (EHT, MTT and CFT) a sealing agent was applied on the retention screw, whereas the control groups (EHC, MTC and CFC) were maintained in the conventional manner. All implants were embedded in polyurethane and into the deeper portion of each implant it was introduced 0.7 μl of Toluidine Blue (TB). After that, the abutments were screwed to the implants with the torque values recommended by the manufacturer with the aid of a specific wrench and a digital torque wrench. The specimens formed were submitted to mechanical cycling (1x106 cycles) with frequency of 2Hz and oblique loading of 130 N. The misfit evaluation were performed at a stereomicroscope before and after a mechanical cycling. In order to verify the gel sealing ability after the mechanical cycling a standard curve was performed to determine the blue toluidine (TB) dilution. Then the data obtained were analyzed in a spectrophotometer for a standard curve formation. Afterwards, the specimens were placed in vials containing 400μl of distilled water. The spectrophotometric analysis was performed at 8 different times (1, 3, 6, 24, 48, 72, 96 and 144 hours). Finally, measurements of final destorque values (post-cycling) were performed. The misfit data, destorque and dye release (sealing ability) were obtained and submitted to normality statistical tests and then analyzed by ANOVA and Tukey tests (α = 0.05). The ANOVA test showed that for detorque evaluation, all the test groups presented values statistically higher (p <0.05) than the control groups. Comparing the types of connections, we could observe a superiority of the flexcone connection (MT implant and flexcone abutment) compared to the others in relation to preload maintenance (p <0.05). In the misfit analysis before and after a mechanical cycling, the EHT group presented a decrease values at post-cycling (p <0.05). In the sealing ability evaluation it was observed that all groups in all periods showed TA release (p <0.05). It was concluded that the test groups showed superior results for detorque and misfit analysis, which could led to a future protocol for the use of the evaluated sealant at the abutment / implant interface. In the evaluation of the sealing capacity both the control and the test groups were not efficient. (AU)