The influence of the modification of etched bovine dentin on bond strengths

• Published in: Dental materials 2000-07, Vol.16 (4), p.255-265
• Main Authors: Phrukkanon, S, Burrow, M.F, Hartley, P.G, Tyas, M.J
• Format: Article
• Language: English
• Subjects: Acid Etching, Dental - methods; Adhesiveness; Animals; Bisphenol A-Glycidyl Methacrylate - chemistry; Bonding; Cattle; Collagenase; Collagenases - pharmacology; Composite Resins - chemistry; Confidence Intervals; Dental Bonding; Dentin; Dentin - drug effects; Dentin - ultrastructure; Dentistry; Hybrid layer; Materials Testing; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Phosphoric Acids - administration & dosage; Regression Analysis; Silicon Dioxide; Sodium hypochlorite; Sodium Hypochlorite - pharmacology; Solvents - pharmacology; Statistics, Nonparametric; Stress, Mechanical; Surface Properties; Tensile Strength; Time Factors; Zirconium
• ISSN: 0109-5641; 1879-0097
• DOI: 10.1016/S0109-5641(00)00015-4

Objective: The aim of this study was to modify demineralized bovine dentin surfaces by application of either 12.5% sodium hypochlorite (NaOCl), or 0.1% (w/w) Type I collagenase, after conditioning with phosphoric acid, to observe the demineralized surface and to investigate the effect on tensile bond strength. Methods: The NaOCl was applied to etched dentin for 30 s, 1 or 2 min and the collagenase for 1, 3 or 6 h. A control group was used without NaOCl or collagenase treatment. Prior to bonding, treated surfaces were examined using an Atomic Force Microscope (AFM). A 2.3 mm diameter area of dentin was conditioned, treated and bonded with either One Coat Bond or Single Bond following each manufacturer's instructions, and a resin composite rod attached. Bonds were stressed in tension at a rate of 1 mm/min until failure. Mean bond strengths were calculated (MPa) and mode of failure was determined by observation at 20× magnification. Results were analyzed using multiple regression analysis and LSD test at the 95% level of confidence ( n=12). Results: AFM results showed progressive changes of the surface collagen as the treatment time of NaOCl or collagenase increased. For both bonding systems, the bond strengths of 1 min NaOCl and 3 h collagenase treatments were significantly higher than the control or other treatment groups ( p