EFFECT OF ER:YAG LASER IRRADIATION ON ENAMEL CARIES PREVENTION

Abstract

Background and Aim: The aim of this study was to examine the effect of Er:YAG laser irradiation on caries-like lesions in a simulated caries model. Materials and Methods: Twenty extracted human noncarious molar teeth were selected. The teeth were covered with nail varnish, leaving two windows (approximately 4mm×2mm) on both the buccal and lingual surfaces at the middle third of the crown. The windows were randomly assigned to the four groups, which were no-treatment (G1), Er:YAG laser (KaVo KEY Laser 3, KaVo Dental GmbH) irradiation alone (G2), acidulated phosplate floride (APF) gel (Sultan/topex Neutral Ph Gel, Sultan Dental Products Ltd) treatment alone (G3) and Er:YAG laser irradiation before APF gel treatment (G4). A two-day pH-cycling was performed, with an 18-hour demineralization followed by a 6-hour remineralization. Sections of 120±20 &#956;m in thickness were obtained from each window. Mean lesion depth was measured using polarized light microscope. Results were statistically analyzed by using Kruskal-Wallis and MannWhitney U tests. Results: Mean lesion depths were 134±32 micrometers for group G1, 90±18 &#956;m for group G2, 109±25 &#956;m for group G3, and 74±23&#956;m for group G4. Mean lesion depths of all treatment groups were significantly less than those for the matched notreatment group (p<0.05). Er:YAG laser irradiation before APF gel treatment significantly reduced lesion depth compared with the no-treatment and APF gel treatment alone (p<0.05). Conclusion: Er:YAG laser irradiation in combination with fluoride treatment was improved resistance to enamel dissolution and reduced the mean lesion depth.