Cynthia P Trajtenberg1, Patricia N R Pereira, John M Powers. 1. Department of Restorative Dentistry and Biomaterials, University of Texas Dental Branch at Houston, 6516 M.D. Anderson Blvd., Suite 493, Houston, Texas 77030-3402, USA. Cynthia.Trajtenberg@uth.tmc.edu
Abstract
PURPOSE: To evaluate the in vitro effect of the Er:YAG laser and high-speed rotary instrumentation on the bond strength of resin composite to human enamel and dentin, and determine which conditioner, either phosphoric acid or a self-etching primer, resulted in higher bond strengths with either of the surface treatments. METHODS: 48 third molars were used. Dentin and enamel specimens were sectioned and polished with 600-grit SiC paper and treated either with carbide bur or an Erbium:YAG laser and treated with one of three different conditions, acid-etch/bonding agent (Scotchbond Multi-Purpose Plus), no etching and same bonding agent, and an experimental self-etching primer (EXL 547). After storage for 48 hours at 37 degrees C and 100% humidity, specimens were prepared in an hourglass shape for microtensile bond test (ca. 1 mm2) and debonded in tension. Areas were measured and bond strengths were calculated for each specimen. Failure modes, micromorphology of surface treatments and bonding interfaces of representative specimens from acid-etched and self-etched groups were analyzed with scanning electron microscopy. Means were compared using three-way analysis of variance, and Scheffé post-hoc test (P < 0.05) was used to determine differences among surface treatments, tooth substrate and conditioners. RESULTS: Dentin prepared with the carbide bur and treated with phosphoric acid followed by the application of Scotchbond Multi-Purpose had the highest bond strengths (35.7 MPa). Enamel and dentin prepared with the Er:YAG laser had the highest bond strengths when the surfaces were acid-etched followed by Scotchbond Multi-Purpose (25.8-21.1 MPa). Carbide bur exhibited higher bond strengths than laser with the use of the experimental self-etching primer but laser showed higher bond strengths than the bur with the use of Scotchbond Multi-Purpose and no etching. The predominant failure mode of most of the treatment conditions was partially adhesive between the bonding resin and enamel or dentin, and partially cohesive within the bonding resin. SEM analysis revealed the absence of a smear layer on laser-treated teeth when compared to untreated control and bur-cut teeth.
PURPOSE: To evaluate the in vitro effect of the Er:YAG laser and high-speed rotary instrumentation on the bond strength of resin composite to human enamel and dentin, and determine which conditioner, either phosphoric acid or a self-etching primer, resulted in higher bond strengths with either of the surface treatments. METHODS: 48 third molars were used. Dentin and enamel specimens were sectioned and polished with 600-grit SiC paper and treated either with carbide bur or an Erbium:YAG laser and treated with one of three different conditions, acid-etch/bonding agent (Scotchbond Multi-Purpose Plus), no etching and same bonding agent, and an experimental self-etching primer (EXL 547). After storage for 48 hours at 37 degrees C and 100% humidity, specimens were prepared in an hourglass shape for microtensile bond test (ca. 1 mm2) and debonded in tension. Areas were measured and bond strengths were calculated for each specimen. Failure modes, micromorphology of surface treatments and bonding interfaces of representative specimens from acid-etched and self-etched groups were analyzed with scanning electron microscopy. Means were compared using three-way analysis of variance, and Scheffé post-hoc test (P < 0.05) was used to determine differences among surface treatments, tooth substrate and conditioners. RESULTS: Dentin prepared with the carbide bur and treated with phosphoric acid followed by the application of Scotchbond Multi-Purpose had the highest bond strengths (35.7 MPa). Enamel and dentin prepared with the Er:YAG laser had the highest bond strengths when the surfaces were acid-etched followed by Scotchbond Multi-Purpose (25.8-21.1 MPa). Carbide bur exhibited higher bond strengths than laser with the use of the experimental self-etching primer but laser showed higher bond strengths than the bur with the use of Scotchbond Multi-Purpose and no etching. The predominant failure mode of most of the treatment conditions was partially adhesive between the bonding resin and enamel or dentin, and partially cohesive within the bonding resin. SEM analysis revealed the absence of a smear layer on laser-treated teeth when compared to untreated control and bur-cut teeth.
Authors: Andreia Cristina Bastos Ramos; Marcella Esteves-Oliveira; Victor E Arana-Chavez; Carlos de Paula Eduardo Journal: Lasers Med Sci Date: 2008-08-21 Impact factor: 3.161
Authors: Marcelo Tavares de Oliveira; Patrícia Moreira de Freitas; Carlos de Paula Eduardo; Glaucia Maria Bovi Ambrosano; Marcelo Giannini Journal: Eur J Dent Date: 2007-07