Purpose: Pulp chamber floor perforations were created in extracted teeth, and dentin was pretreated using EDTA or Nd:YAG laser. Then, a microleakage test was conducted, and polymerization of light-cured composite resin using the argon laser or a halogen lamp was compared. Materials and Methods: Thirty-six extracted teeth were divided into 6 groups, and after root canal preparation and filling in a conventional manner, a hole was artificially made in the pulp chamber floor. For dentin pretreatment prior to placing the filling material, 15% EDTA or Nd:YAG laser was applied. Either amalgam or light-cured composite resin was used as filling material. Either the argon laser or halogen lamp was employed as the light source for polymerization. The entire surface was coated using nail varnish, and the tooth was soaked in 1% rhodamine solution to assess dye leakage. Using stereoscopic and scanning electron microscopes, adhesion between the filling material and cavity margin, and dye penetration were observed. The results were statistically analyzed using a Kruskal-Wallis test. Results: The microleakage test showed no statistically significant difference between dentin pretreatments with EDTA application and Nd:YAG laser application. However, when amalgam was used, dye leakage was seen in all cases regardless of the method of dentin pretreatment. SEM observation showed that when a light-cured composite resin was used, the volume of smear layer with Nd:YAG laser was less when compared to EDTA. Conclusions: Pulp chamber floor perforations can be effectively treated by eliminating the smear layer using the Nd:YAG laser and polymerizing the light-cured composite resin using the argon laser.
Keywords: pulp chamber floor perforation, Nd:YAG laser, argon laser, dye penetration, smear layer, SEM