title: The effect of a 980 nm diode laser with different parameters of irradiation on the bond strength of fiberglass posts.
abstract: The aim of this study was to assess bond strength of fiberglass posts to root canal dentin irradiated with a 980 nm diode laser at different parameters of power and frequency. Fifty human maxillary canines were separated into five groups (n = 10) according to the following parameters of laser power and frequency: Group 1 (1.5 W/100 Hz), Group 2 (1.5 W/continuous wave [CW]), Group 3 (3.0 W/100 Hz), Group 4 (3.0 W/CW), and Group 5 (no irradiation). Following post cementation, samples underwent a push-out test (0.5 mm/min); next, fracture analysis was performed with a light microscope at 50x and 100x magnification. All of the irradiated groups had increased bond strength values compared to the nonirradiated group. Groups 1 and 2 demonstrated the highest bond strength values; however, statistically significant differences were observed for only the cervical third of Group 4 and the cervical/apical thirds of Group 5. Fracture analysis showed a predominance of mixed failures for Groups 1 and 2 and adhesive failures between dentin and cement for the other groups.
authors: Department of Dental Materials and Prosthodontics, dental School of Ribeirao Preto, University of Sao Paulo, SP, Brazil.
authors: Lucas da Fonseca Roberti
authors: Lda F
authors: Garcia
authors: Lucas Zago
authors: LZ
authors: Naves
authors: Ana Paula
authors: AP
authors: Farina
authors: Cristiane Mezzena
authors: CM
authors: Walker
authors: Simonides
authors: S
authors: Consani
authors: Fernanda de Carvalho Panzeri
authors: Fde C
authors: Pires-de-Souza