296 A.T. Araki et al. Er:YAG Laser Irradiation of the Microbiological Apical Biofilm

One problem in cases of healing-resistant periapical lesions is to eradicate the contamination at the periapical area. This contamination is due to the microbiological biofilm formed by microorganisms and their subproducts lodged in apical third of the root, on both cementum and dentin surface. Paraendodontic surgery consists of the mechanical removal of harmful agents to promote healing and periapical health. The purpose of this study was to assess the results of Er:YAG laser irradiation on the apical root third of newly extracted teeth to eliminate microbial contamination on root apex surface. Apical irradiation was performed with an Er:YAG laser device using an experimental contact tip, at 100 mJ, 10 Hz, 1 W, 39 J/cm, 3 times on the target area. SEM analysis showed the elimination of part of the irradiated cementum and the formation of small roughened without exposing the subjacent dentin. Vaporization of the remaining periodontal tissue and removal of microbiological apical biofilm (MAB) were also observed on the irradiated areas. Under the tested conditions and based on the findings of this study, Er:YAG laser may be considered effective for removal of microbiological apical biofilm