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


CONCLUSIONS
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.
Faculty of Dentistry, University of Seville (US), C/ Avicena, s/n, 41009 Sevilla, Spain.
Paloma
P
Montero-Miralles
Faculty of Dentistry, Complutense University of Madrid (UCM), Pza. Ramón y Cajal, s/n, 28040 Madrid, Spain. Electronic address: raquel.castillo@odon.ucm.es.
Raquel
R
Castillo-Oyagüe
Faculty of Dentistry, University of Seville (US), C/ Avicena, s/n, 41009 Sevilla, Spain.
Isabel
I
Sáez de la Fuente
School of Dentistry, Cardiff University, CF14 4XY Cardiff, Wales, UK.
Christopher D
CD
Lynch
Faculty of Dentistry, University of Seville (US), C/ Avicena, s/n, 41009 Sevilla, Spain.
Gabriel
G
Castillo-Dalí
Faculty of Dentistry, University of Seville (US), C/ Avicena, s/n, 41009 Sevilla, Spain.
Daniel
D
Torres-Lagares
D003786:Dental Pulp Cavity / Q000528:radiation effects* / Q000648:ultrastructure; D003804:Dentin / Q000528:radiation effects* / Q000648:ultrastructure; D004853:Epoxy Resins / Q000737:chemistry / Q000627:therapeutic use; D005456:Fluorescent Dyes; D006171:Gutta-Percha / Q000737:chemistry / Q000627:therapeutic use; D006801:Humans; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008422:Materials Testing; D018613:Microscopy, Confocal; D011897:Random Allocation; D012235:Rhodamines; D012387:Root Canal Filling Materials / Q000737:chemistry / Q000627:therapeutic use*; D012389:Root Canal Obturation / Q000379:methods; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*; D013499:Surface Properties; D019227:Tooth Apex / Q000528:radiation effects / Q000648:ultrastructure
D004853:Epoxy Resins; D005456:Fluorescent Dyes; D012235:Rhodamines; D012387:Root Canal Filling Materials; C534916:epoxy resin-based root canal sealer; D006171:Gutta-Percha; C027755:rhodamine isothiocyanate
Confocal microscope; Dentinal permeability; Endodontic instrumentation; Endodontic sealer; Nd:YAG laser; Sealer penetration