Shear bond strength of glass-ionomer cements to air-abraded dentin.
OBJECTIVE
The aim of this in vitro study was to evaluate the shear bond strength of two conventional glass-ionomer cements to bovine dentin when using the air-abrasion technique for cavity preparation.


METHODS
Forty bovine central incisors were selected, embedded in polyester resin, and ground until the dentin surface was exposed. The teeth were randomly assigned to four groups: I and II--rotating instrument with a carbide bur; III and IV--an air-abrasion system. Groups I and III were restored with Fuji IX and groups II and IV with Ketac Molar. A 3-mm-diameter bonding site was delimited and treated with 10% polyacrylic acid for 10 s in the Fuji IX subgroups and with 25% polyacrylic acid for 10 s in the Ketac Molar subgroups. After surface treatment, a glassionomer cylinder was prepared for each specimen, using a split bisected Teflon matrix. The finished specimens were submitted to the shear bond strength test in a universal testing machine at a crosshead speed of 0.5 mm/min. The data were analyzed using ANOVA and Scheffé statistical tests. The dentin bonding areas were analyzed under a stereoscopic optical magnifier (40X) to assess the type of failure.


RESULTS
The mean (SD) shear bond strengths in MPa were: group I--3.49 (+/- 3.77), group II--7.17 (+/- 2.93), group III--7.55 (+/- 2.99), group IV--5.67 (+/- 3.90). Ketac Molar showed higher bond strength values in bur-prepared cavities, while on the air-abraded preparations, Fuji IX showed superior results.


CONCLUSIONS
It can be concluded that the air-abrasion system used for cavity preparations may influence the bonding performance of conventional glass-ionomer cements to dentin.
de Souza-Zaroni
Wanessa Christine
WC
Department of Restorative Dentistry, Ribeirio Preto School of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil.
Nhani
Vanessa Tessari
VT
Ciccone-Nogueira
Juliane Cristina
JC
Chinelatti
Michelle Alexandra
MA
Palma-Dibb
Regina Guenka
RG
Corona
Silmara Aparecida Milori
SA
D000818:Animals; D002417:Cattle; D001840:Dental Bonding / Q000379:methods*; D003737:Dental Cavity Preparation / Q000379:methods*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D033081:Shear Strength; D014072:Tooth Abrasion
D017220:Dentin-Bonding Agents; C439808:Fuji IX GP Fast; D005899:Glass Ionomer Cements; C110712:ketac-molar