Purpose: The objective of the present study was to compare the effect of the conventional carbide bur and Er:YAG laser (contact mode) used for apical resection on the roots of teeth obturated using the lateral compaction technique with various sealers and gutta percha points. Materials and Methods: A total of 120 noncarious extracted human teeth was collected for the study. Access cavities were prepared and the teeth were cleaned and shaped. Following obturation, the apical 3 mm of the teeth were resected using either the bur or Er:YAG (2940 nm wavelength) laser in contact mode. ESEM was used to evaluate micromorphological changes in the structure of dentin and effects on the obturation material. Results: ESEM examination revealed a smooth sectioning of the apical third in all samples at low magnification. Higher magnification showed that the bur and the laser were equally effective in sectioning the tooth and obturation material. The laser sections showed melting of dentin and sealing of dentinal tubules. However, microgaps were seen in all specimens at the root canal dentin wall/obturation-material interface. Conclusion: Although the carbide bur and Er:YAG laser are equally effective in sectioning the apical third, the presence of microgaps indicates the necessity of providing a good apical seal with retrograde filling material for preventing microleakage following resection.
Keywords: dental lasers, carbide bur, Er:YAG laser, endodontics, apical resection, ESEM analysis