Gracey Curettes Vs Air-Polishing: In Vitro Comparative Study

Objectives: In the last 20 years the trend of abandoning hand-hend tools for mechanical ones is spreading, due to their lower soft tissue damage. The aim of this study was to evaluate the qualitative and quantitative aspects of dental surfaces after Gracey curettes (GC) and air-polishing (AP). Methods: Six extracted teeth with tartar were selected, kept hydrated in 10% formaldehyde solution, 3 totally treated by GC (control), 3 by AP (test) randomly assigning a different powder for each face (glycine 63µm, glass spheres 50µm, bicarbonate 250µm, aluminum dioxide 25µm and pumice in very fine powder). Elements were treated by apicectomy, gold-sputtering, oven drying, SEM observation and photographs. All 2000x magnification images underwent: - surface analysis with roughness indexes Ra, Rq, Sa; - fractal dimension analysis with box counting method, considering average fractal dimension (DB) an standard deviation; - 3D-plottings to improve qualitative analysis. Enamel and cementum results were separately obtained. Statistical analysis was performed. Results: There were no statistically significant differences between GC and AP. Among AP data, test was significant only for Rq and Ra, both in enamel and cementum. Lack of significance for Sa and DB both in enamel and cementum was due to small sample size, maybe representing a false negative. Observing 3D-plots and low-magnification photo, areas treated by GC had deep grooves that were not on any area treated by AP. Conclusions: Non-traumatic GC effects on soft tissue shouldn’t be applied to hard tissue, on which the finding of multiple carvings means an unjustified removal of dental substance, that on roots is a loss of cementum, essential mediator for long junctional epithelium growth. Finally, the comparison between GC and AP requires further investigation, notwithstanding both methods are effective in removing tartar and improving microbiological and clinical parameters.