Bonding of resin to artificially carious dentin.
OBJECTIVE
To evaluate the bond strength of adhesive resins to artificially carious dentin specimens which were previously exposed to an acid buffer solution for various periods.


METHODS
Flat dentin disks were obtained from superficial occlusal dentin of extracted human third molars and polished with wet silicon carbide paper. Dentin disks were immersed in acid buffer solution for different periods to create the demineralized dentin layer. The first group of demineralized specimens was used for the evaluation of demineralization depth under SEM and the second group was used for the bond strength measurement. Shear bond strengths mediated by three dentin adhesives (Clearfil SE Bond, OptiBond Solo Plus Total-Etch, and OptiBond Solo Plus Self-Etch) were examined. A 0.75-mm-diameter area of dentin was bonded according to the manufacturers' instructions before placing a 0.5-mm-high resin composite cylinder. The bonds were stressed in shear at a crosshead speed of 1 mm/min. All data were analyzed using ANOVA and LSD multiple comparison test.


RESULTS
Depth of demineralization increased with the prolongation of demineralizing time. After dentin specimens were demineralized for up to 24 h, bond strengths of the self-etching adhesives were significantly higher than those of the total-etch adhesive. However, for longer demineralization periods, no statistical differences in bond strengths were observed. SEM photographs showed that resins cannot thoroughly infiltrate through the whole depth of the demineralized dentin layer.


CONCLUSIONS
Bond strengths to demineralized, artificially carious dentin were affected by the depth of demineralization and adhesive resins used.
Sattabanasuk
Vanthana
V
Department of Conservative Dentistry and Prosthodontics, Faculty of Dentistry, Srinakharinwirot University, Sukhumvit 23, Bangkok, Thailand. mengvanthana@hotmail.com
Shimada
Yasushi
Y
Tagami
Junji
J
D000269:Adhesives / Q000737:chemistry*; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D003731:Dental Caries / Q000139:chemically induced; D003804:Dentin / Q000187:drug effects; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D019279:Resin Cements / Q000737:chemistry*; D013997:Time Factors
D000269:Adhesives; D017220:Dentin-Bonding Agents; D019279:Resin Cements