Abstract:
Objective: To describe and compare effects of 3 different abutment materials on the attachment evaluation and inflammatory reactions of the soft tissue around abutments at 8 weeks healing period.
Material and Methods: Fifteen posterior edentulous areas were treated with implant restorations. Three types of abutment materials; titanium, zirconia, and gold alloy, were randomly inserted on implant fixtures on the surgery day, 5 abutments of each group. Tissue biopsies from peri-implant tissue around the abutments were harvested at 8 weeks after implant surgery. The specimens were processed using non-separation resin embedded technique and stained with H&E. The characteristics of peri-implant tissue attachment were assessed at clinical stage using gingival index (GI) score, surgical stage (surgical score) and histological stage (attachment percentage). And the inflammatory responds were evaluated using inflammatory extent grade and inflammatory cellularity grade.
Results: All cases of gold alloy group received GI score equal 1, but chi-square test suggests no association between GI score and abutment type (p = 0.071). For Surgical score, zirconia had a better result with 0% of score 3, while 40% in gold alloy group received score 3, but no statistically significant differences were found among groups (p = 0.262). For attachment percentage, titanium and zirconia abutments exhibited almost similar mean attachment percentages while gold alloy abutments received much lower mean percentage. A significant effect on attachment percentage was found among 3 groups (p = 0.004). For inflammatory extent grade and inflammatory cellularity grade, the odds of being one grade higher for gold alloy abutment was 5.18 and 17.8 times that of titanium abutment, respectively. For inflammatory extent grade of zirconia abutment, the odds was 0.87 times lower, and for inflammatory cellularity the odds was 7.5 times higher than that of titanium group.
Conclusions: At 2 months haling period, peri-implant tissue around gold alloy abutments resulted in poorer attachment condition compare to titanium and zirconia abutments. Inflammation tended to be higher in tissue around gold alloy abutments than titanium and zirconia abutments.
