[Effects of dentin demineralization and bond-strength properties of bioactive glass containing resin adhesive].
OBJECTIVE
This study investigated the shear bond strength and the ability of resin adhesive containing different amounts of bioactive glass (BG) to prevent dentin demineralization.


METHODS
BG bonds at 30%, 40%, and 50% concentrations comprised a mixture of coupling agents modifying BG and Single Bond 2. Forty permanent premolars extracted for orthodontic treatment were randomly divided into four groups, namely, control group (BG-free), 30% BG group, 40% BG group, and 50% BG group. Composite resin and dentin were prepared into bonding specimens by using respective adhesives and then immersed in artificial saliva at pH 4 for 1 week. Changes in the pH values of the solution were measured every 24 h. The microtensile bond strength (TBS) of each specimen was examined after immersion in distilled water at 37 °C for 24 h.


RESULTS
The TBS values of the control group, 30% BG group, 40% BG group, and 50% BG group were (27.76±0.29), (27.05±0.58), (26.95±0.69), and (25.12±0.24) MPa, respectively. The TBS of the control group was not significantly different from that of the 30% BG group (P=0.06) but significantly higher than that of the 40% BG and 50% BG groups (P=0.04 and P=0.00, respectively). In addition, TBS was significantly higher in the 30% BG and 40% BG groups than in the 50% BG group (P= 0.00 and P=0.00, respectively). The pH values of the solution increased with increasing BG content.


CONCLUSIONS
BG bonds are useful in the prevention of dentin demineralization. However, in this study, the 30% BG group did not affect the short-term bond strength. The 50% BG group displayed the optimum ability to inhibit demineralization but showed the worst bond strength.
Dept. of Preventive Dentistry, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing 210008, China.
Wang
W
Yu
Dept. of Preventive Dentistry, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing 210008, China.
Gong
G
Ling
Dept. of Preventive Dentistry, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing 210008, China.
Ji
J
Yan
Dept. of Preventive Dentistry, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing 210008, China.
Zheng
Z
Lichun
Dept. of Preventive Dentistry, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing 210008, China.
Chen
C
Song
D000269:Adhesives; D017438:Bisphenol A-Glycidyl Methacrylate; D003188:Composite Resins; D001840:Dental Bonding; D003804:Dentin; D005898:Glass; D006801:Humans; D008422:Materials Testing; D012464:Saliva, Artificial; D013718:Tensile Strength; D017001:Tooth Demineralization
D000269:Adhesives; D003188:Composite Resins; D012464:Saliva, Artificial; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate
bioactive glass; bond strength; dentin; pH value; resin adhesive