A Randomized Clinical Trial of the in vivo effect of non-metallic vs metallic hand scalers on zirconia implant supported crowns during a year of peri-implant maintenance

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Roemermann, Dayna L.
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Background: This study examined whether the degree of abutment surface modification that may occur with regular periodontal instrumentation has a clinical impact in terms of increased plaque accumulation and increased peri-implant tissue inflammation on zirconia implant abutments. Methods: 13 patients who had zirconia implant crowns were recruited in this randomized clinical trial. Each patient acted as their own control, and had either the buccal or lingual surface of their screw retained implant restoration scaled with a metallic scaler, and the other surface with a non-metallic scaler at 3, 6, 9 and 12 months. Cytokine testing of the peri-implant crevicular fluid was completed at 0, 3 and 12 months, for IL-2, IL-4, IL-6, IL-8, IL-10, TNF-a or IFNy. Implant crowns were removed at 12 months and evaluated under an atomic force microscope for the RA, or average roughness, and the Ra, or root mean square roughness, scores. The implant crowns were polished and re-inserted. Results: There were strong significant differences in surface roughness (Ru and Ra) between the metallic and non-metallic scalers, with average Ru values of 417.7m (s = 276.1nm) and 233.9nm (s = 155.6nm), and RA values of 301.0nm (s = 214.2nm) and 176.1nm (s = 123.1nm) respectively. However, there were no significant associations between the type of scaler used and the amount of clinical inflammation or cytokine production. Conclusion: Metallic scalers produce deeper, more aggressive surface alterations to the abutment/crown zirconia surface but there was no statistically significant difference between the degree of surface alterations, amount of BOP, and the amplitude of cytokine inflammation produced.
crowns, randomized clinical trial, RCT, cytokines, scalers