Effects of conditioners on microshear bond strength to enamel after carbamide peroxide bleaching and/or casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) treatment.
OBJECTIVE
To evaluate (a) the enamel microshear bond strength (MSBS) of a universal adhesive and (b) the effects of conditioning with a self-etching primer adhesive with/without prior bleaching and/or casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) application.


METHODS
Thirty-five molars were cut into four sections, assigned randomly to four groups (no treatment; 16% carbamide peroxide bleaching; CPP-ACP-containing paste (Tooth Mousse, TM); bleaching and TM) and treated accordingly. Specimens were divided into two for bonding with either a self-etching primer (Clearfil SE Bond, CSE) or a total-etch adhesive (Single Bond, SB). Specimens for CSE bonding were subdivided for one of four preconditioning treatments (no conditioning; 30-40% phosphoric acid (PA); 15% EDTA; 20% polyacrylic acid conditioner (Cavity conditioner, CC) and treated. The adhesives were applied and resin composite bonded to the enamel using microtubes (internal diameter 0.75mm). Bonds were stressed in shear until failure, mean MSBS calculated and data analysed using ANOVA with Tukey's HSD test (alpha=0.05). The modes of bond failure were assessed and classified.


RESULTS
Two-way ANOVA revealed significant differences between treatments (P<0.0001), conditioners (P<0.0001) and a significant interaction between treatments and conditioners (P=0.001). One-way ANOVA revealed no significant differences in MSBS following any of the treatments for SB; following TM application for CSE without preconditioning; and significant differences in MSBS following bleaching with and without TM application for CSE. With preconditioning, applying PA before CSE post-bleaching and either PA or CC before CSE post-TM application, resulted in significant differences in MSBS (P<0.05).


CONCLUSIONS
The use of conditioners prior to bonding with the self-etching primer adhesive system on treated enamel may significantly improve bond strengths.
Adebayo
O A
OA
School of Dental Science, University of Melbourne, 720 Swanston Street, Victoria 3010, Australia.
Burrow
M F
MF
Tyas
M J
MJ
D000134:Acid Etching, Dental / Q000379:methods; D000180:Acrylic Resins / Q000737:chemistry; D000268:Adhesiveness; D000328:Adult; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D000077463:Carbamide Peroxide; D002364:Caseins / Q000627:therapeutic use*; D002614:Chelating Agents / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D003743:Dental Enamel / Q000187:drug effects / Q000648:ultrastructure*; D003807:Dentin Sensitivity / Q000517:prevention & control*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D004338:Drug Combinations; D004492:Edetic Acid / Q000737:chemistry; D006801:Humans; D016877:Oxidants / Q000627:therapeutic use*; D010545:Peroxides / Q000627:therapeutic use*; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D014073:Tooth Bleaching; D014508:Urea / Q000031:analogs & derivatives* / Q000627:therapeutic use
D000180:Acrylic Resins; D002364:Caseins; D002614:Chelating Agents; C438313:Clearfil SE Bond; D003188:Composite Resins; D003738:Dental Cements; D017220:Dentin-Bonding Agents; D004338:Drug Combinations; D016877:Oxidants; D010545:Peroxides; D010756:Phosphoric Acids; D019279:Resin Cements; C447032:casein phosphopeptide-amorphous calcium phosphate nanocomplex; C115612:single bond; D000077463:Carbamide Peroxide; D017438:Bisphenol A-Glycidyl Methacrylate; C006903:carbopol 940; D014508:Urea; D004492:Edetic Acid; C030242:phosphoric acid