Analyzing the Effect of Air Polishing on Tooth Surfaces With Two Imaging Methods

The patients were recruited from individuals seeking periodontal and/or dental treatment at Kocaeli University, Faculty of Dentistry. The teeth samples were collected from the participants who have a single-rooted tooth with the gingival recession on all surfaces and need to be extracted. All patients who met the criteria were informed about the study. Patients who gave written informed consent were included. Before the teeth extractions, root surfaces were marked with a bur at the level of the gingival margin. Extractions were performed under local anesthesia with 2% xylocaine adrenalin. Fourteen single root extracted teeth were included into the study. The crown and exposed root surface were air polished using glycine and sodium bicarbonate powders at instrumentation time of 5s, combinations of medium and maximum power and medium water settings, distance of 5mm and angulation of 60 degree.

Samples were scanned before and after air polishing with a high-resolution micro-CT device. The scanning conditions were 100 kVp; 100-mA, 0.5-mm Al/Cu filter; 13.1-μm pixel size; and rotation at 0.2 steps. According to the manufacturer's instructions, each sample was rotated 360°. The mean scanning time was around 1hour. The teeth surfaces were digitalized before and after air polishing with an intraoral scanner. The mean scanning time was around 10 second. The virtual images of the scanned teeth were saved in stereolithography (STL) format. The defect volume was estimated.

The data were analyzed using commercially available statistical analysis software. Descriptive statistics that were used to analyze the results included the mean, standard deviation, median, minimum, and maximum. Mann-Whitney U test was performed to compare differences between two independent variables. Wilcoxon test was used to compare differences between two dependent variables. P-values less than 0.05 were considered statistically significant.