title: Bond Strength of High-Viscosity Glass Ionomer Cements is Affected by Tubular Density and Location in Dentin?
abstract: This study evaluated the influence of tubular density of different dentin depths and location on the bond strength of high-viscosity glass ionomer cements (GIC). A total of 20 molars were selected and assigned into six experimental groups, considering two different high-viscosity GICs-Fuji IX (FIX) or Ketac Molar (KM), and dentin location-proximal, occlusal superficial, or occlusal deep dentin (n=10). Teeth were cut and a topographical analysis of four sections per group was performed to obtain data about the tubular density of each different dentin location and depths by laser scanning confocal microscopy (100×). Polyethylene tubes were placed over the pretreated surfaces and filled with one of the GICs. Microshear bond strength (µSBS) test was performed after storage in distilled water (24 h at 37°C). Failure modes were evaluated using a stereomicroscope (400×). Multilevel regression analysis was performed to compare the results at a significance level set at 5%. The tubule density was inversely proportional to the bond strength for both GICs (p<0.05). Adhesive/mixed failure prevailed in all experimental groups. Proximal (30036.5±3433.3) and occlusal superficial 29665.3±1434.04 dentin shows lower tubule density, resulting in a better GIC bonding performance (proximal: FIX-3.61±1.05; KM-3.40±1.62; occlusal superficial: FIX-4.70±1.85; KM-4.97±1.25). Thus, we can concluded that the lowest tubule density in proximal and occlusal superficial dentin results in a better GIC bond strength performance.
authors.affiliation: Department of Orthodontics and Pediatric Dentistry,School of Dentistry,University of São Paulo,São Paulo 05508-000,Brazil.
authors.forename: Tamara K
authors.initials: TK
authors.lastname: Tedesco
authors.affiliation: Department of Orthodontics and Pediatric Dentistry,School of Dentistry,University of São Paulo,São Paulo 05508-000,Brazil.
authors.forename: Ana Flávia B
authors.initials: AF
authors.lastname: Calvo
authors.affiliation: Department of Orthodontics and Pediatric Dentistry,School of Dentistry,University of São Paulo,São Paulo 05508-000,Brazil.
authors.forename: Gabrielle G
authors.initials: GG
authors.lastname: Domingues
authors.affiliation: Department of Orthodontics and Pediatric Dentistry,School of Dentistry,University of São Paulo,São Paulo 05508-000,Brazil.
authors.forename: Fausto M
authors.initials: FM
authors.lastname: Mendes
authors.affiliation: Department of Orthodontics and Pediatric Dentistry,School of Dentistry,University of São Paulo,São Paulo 05508-000,Brazil.
authors.forename: Daniela P
authors.initials: DP
authors.lastname: Raggio
mesh_terms: D000327:Adsorption; D003804:Dentin / Q000378:metabolism* / Q000648:ultrastructure*; D005899:Glass Ionomer Cements / Q000378:metabolism*; D006801:Humans; D008422:Materials Testing; D018613:Microscopy, Confocal; D008963:Molar; D013696:Temperature; D014783:Viscosity
chemical_list: D005899:Glass Ionomer Cements
keywords: bond strength; confocal microscopy; dentin; glass ionomer cements; permanent tooth