Comparative study of CO2 and Nd:YAG laser on dentin layer of human root canals of permanent teeth utilizing scanning electron microscopy

摘要

The present paper investigated the effects of two different laser beams on dentin and root canal walls. Five human intact teeth (incisors and canines), with endodontic treatment accomplished by Paiva and Antoniazzi technique, had their crowns separated from the roots using a diamond teeth. After polishing the dentin surfaces, they were irradiated with CO$- 2$/ and NdYag laser and analyzed using SEM and light microscopy. The light microscopy revealed some cicunscribed carbonized areas with some cracks of varied depths in all samples but indicated that the CO$-2$/ laser, at power level of 5 watts, was more effective than NdYag laser at power level of 2 watts. The SEM showed formation of circular depressions with areas containing dentin fusion, melted dentin on small holes on the vitrified surfaces. From the data obtained, it was concluded that the methods analyzed are able to remove the remaining residues on the dentin layer and root canal walls. However, no complete fusion of the dentin layer occurred.