원저 : In situ 연구를 통한 치약의 연마도 평가

Objectives. The aim of this study was to evaluate the effect of two different abrasive toothpastes on the dentine surface using an in situ method. Methods. The dentifrices used in this study had relative dentine abrasion (RDA) values of 30 and 100 when measured by a radioactive dentine abrasion method. They were analyzed using a double blind, randomized, split mouth, in situ study. Dental hygienists trained the subjects in correct tooth brushing techniques with intra-oral appliance using a powered toothbrush prior to the experimental demonstration. The subjects wore bi-lateral, lower appliances from 9 a.m. to 3 p.m. (excluding one hour of lunchtime) for 14 days. Brushing was performed 3 times a day (9 a.m., 12 p.m. and 3 p.m.) for 14 days. The human dentine specimens installed on the appliance were brushed with different tooth brush heads depending on the type of toothpaste, and 1 g of the toothpaste was applied to each specimen for 60 seconds. After 14 days, specimens were removed from the appliances and average dentine loss was measured by a non-contact profilometer. The average dentine loss of each dentifrice was compared by a paired t-test using SPSS 17.0 software. Results. Sixteen subjects were included in the main analysis. The average age of subjects was 23.7 (range; 21∼29). The dentine loss depth of the high-abrasive toothpaste (6.60 μm) was statistically higher than that of the low-abrasive toothpaste (4.23 μm) (p＜0.05). Conclusions. The low-abrasive toothpaste group (RDA 30) showed a significantly lower average dentine loss depth when compared to the high-abrasive toothpaste (RDA 100), and this difference observed in vitro also appeared to exhibit valid results when applied to the in situ study.