Effect of the Nd:YAG laser on sealer penetration into root canal surfaces: A confocal microscope analysis

Abstract

ObjectivesThe objective of this in vitro study was to evaluate the use of the Neodymium:Yttrium-Aluminium-Garnet (Nd:YAG) laser as part of the root canal treatment on the penetration of sealer into dentinal tubules. MethodsEighty extracted lower premolars were randomly assigned to two groups (n=40 each): Control group (CG), subjected to a conventional protocol of endodontic instrumentation and obturation; and Laser group (LG), in which Nd:YAG laser irradiations were combined with conventional preparation and obturation. Endodonted samples were sectioned at 3 and 5mm from the apex and observed under a confocal scanning microscope (CLSM). The penetration depth into the dentinal tubules and the extension of the intracanal perimeter infiltrated by sealer were measured. The Student–Newman–Keuls test was run for between-group comparisons (α=.05). ResultsThe depth of sealer penetration into dentinal tubules did not differ among groups. LG samples showed the significantly highest percentage of penetrated perimeter at 3mm from the root apex. Within each group, the greatest depth of penetration (P=.0001), and the major percentage of penetrated perimeter (P<.001), were recorded at 5mm. ConclusionsThe application of the Nd:YAG laser after instrumentation did not improve the depth of sealer penetration into the dentinal tubules. The laser enlarged the total penetrable perimeter near the apex. Clinical significanceThe Nd:YAG laser may be an appropriate complement in root canal treatment, as it enhances the sealer adaptation to the dentinal walls in the proximity of the apex.