Influência do laser de Nd:Yag na resistência de união de Materiais resinosos à dentina. Efeito do laser de Nd : Yag e de Er:Yag na interface adesivodentina : estudo em MEV

• Ano de defesa: 2008
• Autor(a) principal: Ghiggi, Paula Cristine
• Orientador(a): Spohr, Ana Maria
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Pontifícia Universidade Católica do Rio Grande do Sul; Porto Alegre
• Palavras-chave em Português: ODONTOLOGIA; DENTÍSTICA; ADESIVOS DENTÁRIOS; LASER - ODONTOLOGIA
• Link de acesso: http://hdl.handle.net/10923/404

This study evaluated the bond strength of different adhesive materials on dentin with Nd:YAG laser. Eighteen third human molars, extracted due to therapeutic recommendation, had their roots included in self-cured acrylic resin. Occlusal enamel was removed using a diamond saw and the dentin surface was exposed, followed by surface regularization with 400 and 600 grit silicon carbide sandpaper under water cooling. Teeth were randomly divided in 6 groups: Group 1 – adhesive system Adper Single Bond 2; Group 2 – adhesive system Clearfil SE Bound; Group 3 – self-adhesive resin luting cement Rely X Unicem; Group 4 – irradiation with Nd:YAG laser and application of Adper Single Bond 2; Group 5 – irradiation with Nd:YAG laser and application of Clearfil SE Bond; Group 6 – irradiation with Nd:YAG laser and application of Rely X Unicem. Nd:YAG was applied in the following parameters: 60 mJ, 15 Hz, 0. 9 W, 47,77 J/cm2, 100 μs. Composite resin blocks with 6 mm height were built upon the adhesive materials. Tooth/resin sets were stored in distilled water at 37º C for 24 hours and then cut with a diamond saw using a laboratory cutting machine to obtain the beams samples. Twenty samples were selected in each group, and submitted to microtensile bond strength on a universal testing machine EMIC DL – 2000 at crosshead speed of 0,5mm/min. Results were evaluated according to Variance Analysis and Tukey test ( =0,05). The highest bond strength mean was obtained with Clearfil SE Bond (41. 75 MPa) without laser application. However, when the laser was applied, the bond strength value decreased (33. 42 MPa), but without statistically significant differences. The bond strength of Adper Single Bond without laser application (32. 15 MPa) did not differ statistically from Group 4 (35. 38 MPa). Self-adhesive resin luting cement Rely X Unicem obtained the lowest bond strength, being the value with laser application (7. 53 MPa) statistically lower than the value without laser application (14. 50 MPa). It was concluded that Nd:YAG laser did not decrease significantly the bond strength of the adhesive systems studied, only for the self-adhesive resin luting cement.