Effect of Surface Characteristics of Different Implant Abutment Materials on the Microbial Adhesion- An Invitro Study

Introduction: In two-stage implants, micro-gap between the fixture and the abutment and the superstructure are the potential areas to cause peri-implantitis. The surface roughness and surface energy of the implant abutment materials play an important role in the microbial colonisation on their surface and can help the clinician to choose a better implant abutment material in terms of microbial affinity. Aim: To evaluate the effect of surface characteristics of different implant abutment materials on microbial adhesion. Materials and Methods: The comprehensive analytical experimental study was conducted at KAHER KLE VK Institute of Dental Sciences, Belagavi between Jan 2017- Dec 2017. Forty-five (n=45) identical disc shaped specimens were fabricated using; Zirconia (Group A), Titanium alloy (Group B) and Surgical Grade Stainless Steel (Group C). The surface roughness was assessed for all test groups by Profilometer and Scanning Electron Microscope (SEM). The Surface energy was evaluated for all the test group specimens using Goniometer. Microbial adhesion and assessment were performed using sonicating and vortexing method for all the three groups using three different bacterial strains. The Colony Forming Units for all the specimens were tabulated and subjected to statistical analysis to draw the conclusions from the resultant data.The resultant data was analysed using SPSS software (Version 20). In order to collectively compare the means of the study groups pair-wise comparison of the test group was done using paired t-test with (p<0.05), and correlation between the surface parameters and CFU counts was done using Karl Pearson’s correlation coefficient. Results: On pair-wise comparison of three Groups (A, B, and C) with respect to surface roughness, there were statistically significant differences in surface roughness Ra values between all the groups p<0.001. On pair-wise comparison of all the three Groups with respect to surface energy, there were statistically significant differences in Wetting Angle (WA) values between all the groups (p<0.001**) except between group B and A (p=0.15). Zirconia showed the least CFU counts for Pi and Aa though the differences were not statistically significant. Karl Pearson’s correlation coefficient between surface roughness and surface energy with CFU counts showed a strongly positive correlation for all microbial species and were statistically significant p<0.001**. Conclusion: There was a strongly positive correlation of surface roughness and surface energy to CFU counts. Zirconia showed a low colonisation potential against P.intermedia and A.actinomycetemcomitans than titanium alloy and surgical grade stainless steel.