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Effect of the Nd:YAG laser on sealer penetration into root canal surfaces: a confocal microscope analysis
Paloma Montero-Miralles1, Raquel Castillo-Oyagüe2, Isabel Sáez de la Fuente1
1Faculty of Dentistry, University of Seville (US), C/ Avicena, s/n, 41009 Sevilla, Spain.
Objectives:
The 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.
Methods:
Eighty 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 5 mm 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).
Results:
The depth of sealer penetration into dentinal tubules did not differ among groups. LG samples showed the significantly highest percentage of penetrated perimeter at 3 mm 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 5 mm.
Conclusions:
The 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 Significance:
The 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.

