Effect of a Customised Chairside Polishing Protocol for Zirconia- A Comparative Analysis

The purpose of this study was to develop a customized polishing protocol using standard zirconia polishing kit with polishers of different grit and to study their effect on the surface roughness of zirconia and compare it to that of laboratory polished zirconia samples and machine polished titanium implant abutments. Methods: The samples used in this study were 15 zirconia blocks and 10 machine polished titanium implant abutments (5 Biohorizon and 5 MIS). The 15 zirconia blocks were again divided into three groups. The first group consisted of 5 zirconia samples polished by customised polishing protocol (coarse + medium+ fine). The second group consisted of 5 zirconia samples which were sent to lab1 which used Komet company burs and 5 zirconia samples were sent to lab2 which used carborundum burs and sandpaper for polishing. The fourth group consisted of 5 machine polished titanium implants from MIS system and fifth group consisted of 5 machine polished titanium implants from Biohorizon system. After polishing, the mean surface roughness values (Ra) of zirconia samples and titanium implant abutments were calculated quantitatively by optical profilometer and qualitatively by scanning electron microscope (SEM). Results: The mean surface roughness value of customised polishing protocol using coarse+medium+fine polisher was 0.11 µm which was almost equal to the mean surface roughness values of lab1 polished zirconia samples - 0.131 µm and that of machine polished titanium implant abutments –Biohorizon: 0.201 µm MIS: 0.0859 µm and was within the optimal range of 0.2µm. Conclusions: Within the limitations of this study it was concluded that, the mean surface roughness values of zirconia samples polished by customised polishing protocol , lab1 polished samples and machine polished titanium implant abutments were found to be similar & closer to the critical Ra values (0.2µm) suggesting that the chairside polishing of zirconia can be carried out using the customized polishing technique