J Oral Laser Applications 8 (2008), No. 4 (12.01.2009)
Morphological Study on Apicoectomy by High-Powered Er:YAG Laser
Shimizu, Takashi / Koba, Kenji / Kinoshita, Jun-Ichiro / Matsumoto, Koukichi
Purpose: In order to investigate the possibility of using the Er:YAG laser for apicoectomy and root-end sealing, the procedure time, dye penetration at the site of root-end sealing, and surrounding morphological differences were investigated.
Materials and Methods: In 48 extracted human mandibular second premolars, root canal therapy was performed in the conventional manner. The Er:YAG laser was used for apicoectomy at either 3, 5, or 7 W. After preparing a root-end cavity about 5 mm deep, root-end sealing was performed using amalgam or light-cured resin. For control, an engine-driven fissure bur was used. Next, the root apex was polished, and dye penetration was assessed at depths of 1, 2, 3, and 4 mm. Morphological observations were carried out by x-ray imaging, stereoscopic microscopy, and scanning electron microscope (SEM).
Results: When compared to the conventional rotary cutting device, the time required for 5- or 7-W laser apicoectomy was significantly shorter. The cut dentin surface in the laser application group was smooth, and carbonization, fissures, and marked evaporation were not seen. Dye leakage was only slight, with no significant difference between the laser and control groups (p < 0.01).
Conclusions: The time for apicoectomy using the Er:YAG laser was shorter when compared to apicoectomy using the engine-driven rotary cutting device, and the level of dye leakage was comparable to the conventional method. The cut surface for root-end sealing had no residual smear layer and was clean. Favorable results were obtained with 3-W laser application in terms of cut surface condition, therapy time, and sealant gap.
Keywords: Er:YAG laser, apicoectomy, root-end sealing, leakage test, treatment time, SEM