Effect of glycine powder air-polishing on the gingiva

Objectives: Safety and efficacy of glycine powder air-polishing (GPAP) in removing subgingival biofilm have been previously demonstrated. The hypothesis that GPAP results in less gingival erosion than sodium bicarbonate air-polishing (SBAP) or hand-instrumentation was assessed. Material and Methods: In each of 10 patients, eight teeth with a residual probing depth of at least 5 mm following initial periodontal therapy were randomly assigned to the following interventions: GPAP (test), SBAP (positive control), hand-instrumentation (positive control), or no treatment (negative control). In each group, gingival biopsies were taken immediately after instrumentation and one 14 days later. Damaged gingival epithelium (GE) was assessed by light microscopy and quantified by a histological score (values 1-4). Differences between groups were evaluated using the marginal homogeneity test. Results: GPAP resulted in minor erosions of the GE (scores 1 and 2), whereas positive control specimens displayed moderate to severe erosions (scores 2-4). Differences between GPAP and positive controls were significant (p < 0.05). Fourteen days following instrumentation GE under assessment was found to be intact in all groups. Conclusion: The data indicated that GPAP results in less gingival erosion than SBAP or hand instrumentation, further supporting the safety of this new debridement technique.