title: Analysis of hybrid layer thickness, resin tag length and their correlation with microtensile bond strength using a total etch adhesive to intact dentin.
abstract: The objective of this study was to evaluate the use of a two-step total etch and rinse adhesive, the correlation between the hyybrid layer thickness (HL) and bond strength (BS), and between resin tag length (RT) and bond strength in the same teeth, and also to evaluate the fracture patterns of the tested specimens. Ten human molars were used for the restorative procedure and then sectioned in two halves (mesio-distally). The materials used were Adper Single Bond 2, 3M ESPE, Ultra etch gel, Ultradent and Filtek Z250, 3M ESPE. One half were utilized to measure the HL thickness and RT length through light microscopy analysis (400x), and the other half was subject to a microtensile test to measure the BS. The fractured surfaces were analyzed by scanning electron microscopy and fracture patterns classified. The Pearson correlation test was applied (p = 0.05). The results of the analyses of each specimen then were correlated: mean HL thickness = 4.39 (0.48) microm, mean length of RT = 9.94 (1.69) microm, mean BS = 23.98 (10.24) MPa. A statistically significant correlation between HL thickness and bond strength was found (r = 0.93). The two step etch and rinse adhesive system, showed a strong correlation between HL thickness and bond strength. The most common fractures were adhesive, followed by cohesive in resin.
authors.affiliation: Department of Dental Materials and Prosthodontics, São Paulo State University, Faculty of Dentistry of Araçatuba-UNESP, São Paulo, Brazil.
authors.forename: Rodolfo B
authors.initials: RB
authors.lastname: Anchieta
authors.forename: Fernanda G
authors.initials: FG
authors.lastname: Oliveira
authors.forename: Renato H
authors.initials: RH
authors.lastname: Sundfeld
authors.forename: Vanessa
authors.initials: V
authors.lastname: Rahal
authors.forename: Lucas S
authors.initials: LS
authors.lastname: Machado
authors.forename: Rodrigo S
authors.initials: RS
authors.lastname: Alexandre
authors.forename: Maria L M M
authors.initials: ML
authors.lastname: Sundefeld
authors.forename: Eduardo P
authors.initials: EP
authors.lastname: Rocha
mesh_terms: D001840:Dental Bonding; D003738:Dental Cements; D003799:Dental Stress Analysis; D003804:Dentin; D017220:Dentin-Bonding Agents; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D008963:Molar; D012117:Resins, Synthetic; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D003738:Dental Cements; D017220:Dentin-Bonding Agents; D012117:Resins, Synthetic