Abstract: PURPOSE: To evaluate the clinical effect of 65 μm glycine powder air-polishing (GPAP) by comparing with sodium hydrogen carbonate after ultrasonic scaling during subgingival polishing. METHODS: Thirty-three patients who were systematically healthy were involved in this study. After ultrasonic scaling,they were randomly assigned to the experimental group or the control group. Patients in the control group were treated with rubber cup + sodium hydrogen carbonate, while patients in the experimental group were treated only with 65 μm GPAP therapy. The clinical parameters including probing depth(PD), bleeding index(BI), plaque index(PI), staining index(SI) were recorded at baseline, 1week, 1 month, 3 months and 6 months after treatment. The results were analyzed by paired sample Wilcoxon signed-rank test with SPSS 23.0 software package. RESULTS: Both methods had good clinical effects. PD, BI, PI and SI of the two groups at 1 month, 3 months and 6 months after treatment were significantly better than those at baseline (P<0.01). SI of the experimental groups was significantly lower than that of the control group at 1 month, 3 months and 6 months after treatment(P<0.01). CONCLUSIONS: The results indicated that 65 μm GPAP may be as effective as sodium hydrogen carbonate after ultrasonic scaling in removal of dental plaque and stain. 65 μm GPAP had the advantage of reducing restaining.

Key words: Glycine, Air-polishing, Ultrasonic scaling, Roughness, Stain