جستجوی مقالات مرتبط با کلیدواژه "اباتمنت دندانی" در نشریات گروه "پزشکی"

Microgap found in implant-abutment connection is still one of the main problems that may lead to mechanical and biological failure and inflammation around implants. This study aimed to evaluate the effect of GapSeal on microgap and microleakage between fixture and abutment in internal hex connections. The experiment was performed using 12 implants to check the efficacy of sealing agent at the IAI. The implants were divided into 2 groups of 6 implants each: a group that used no sealing agent at the IAI and a group that used GapSeal at the IAI. Each sample mounted in the acrylic polymerized resin. GapSeal was applied between the fixture and abutment then abutments were assembled using a torque of 30N by digital torque meter. Then cyclic load was applied with the force of 80N and frequency of 1 Hz on the longitudinal axis of each sample. After 500000 cycles, for assessment of microleakage methylene blue solution was used. All set of fixture-abutment (case and control) immersed in the solution and all samples were placed in the incubator (37◦c) for 24 hour. Then the implant-abutments were cross sectioned longitudinally with cutting machine (figure 2) then micro-leakage and microgap were measured by Scanning electron microscope (×200) in the 3 points in each half circle. Finally data was evaluated by t-test. The mean microgap was 0.99±0.39 for GapSeal group that was significantly lower (P<0.000) than that of control group (3.04±0.54).
Also, results showed microleakage in all samples of control group whereas none of the samples of Gapseal group had microleakage. GapSeal caused less microgap and microleakage in implant-abutment interface.

For the clinical success of implant-retained prostheses, fitness of matching components and stability of the applied torque to the implant-abutment assembly under dynamic occlusal loading is essential. The aim of this study was to evaluate the torque loss in Co-Cr castable abutments after cyclic loading.
10 castable abutments were cast in Co-Cr alloy with similar size and height. Each specimen was mounted vertically on a separated implant using a 30 Ncm tightening torque. The detorque values of the abutments were evaluated after 10 min. The same tightening torque was applied to the abutments on their corresponding implants and cyclic loading was applied for 500,000 cycles to the implant-abutment assembly. The torque values after cyclic loading were recorded for each specimen. T-test analysis was conducted on scores from the groups.
Resultes: The results of this study showed that the percentage of torque loss in castable abutments was significantly increased after cyclic loading (P Misfit between the castable implant components can cause torque loss before and after cyclic loading. However, it is more appropriate to relate the results of this study to the screw loosening of the above mentioned abutments than judging their clinical performance.