ABSTRACT
Objective:To study the sealing effect of penetrating resin and fluid resin on the exposed dentin with self-etching and to-tal-etching methods,respectively.Methods:60 fresh extracted teeth were randomly divided into 4 groups(n =15).The enamel layer at the tooth neck was cut off,the dentin layer was exposed and adhered with penetrating resin Icon-Infiltration following Icon-Etch etching(group A),Icon-Infiltration following SE-Bond etching(group B),FiltekTMZ350X following SE-Bond etching(group C)and Prime &Bond NT combined with FiltekTMZ350XT following Gluma acid etching(group D),respectively.The morphological change of the dentin-resin interface was examined by the scanning electron microscope.The thickness of adhensive layer hybrid layer and the length of resin tag were measured.Data were statistically analysed.Results:Tight adhesion layer was observe in all groups.The hy-brid layer of the adhesive interface of group D was thicker than that of other groups(P <0.05);the resin tags in the dentin tubules of group A were longer than those of other groups(P <0.05);the bonding agent layer of group C was the thickest(P <0.05).Conclu-sion:The penetrating resin can form more effective protection layer on the exposed dentin surface and longer resin tags pernertrating in-to the dentin tubules than self-etch/total-etch bond system with fluid resin.
ABSTRACT
The purpose of this study was to evaluate the effects of cyanate methacylate on the shear bond strengths to bovine dentin surfaces as a dentin primers. Seven experimental adhesives were made with different mass fraction of Isocyanatoetylmethacrylate (IEM), 40wt% HEMA (Wako Pure Chemical Industries Osaka, Japan), 0.6% camphoroquinone, 0.4% amine and ethanol as balance. dentin bonding agents (0, 2, 4, 6, 8, 10, 12%) were made and applied on the surface of bovine dentin specimens of 7 experimental groups. Shear bond strengths were measured using a universal testing machine (Instro 4466). To identify the ratio and modes of cohesive failures, microscopic examinationn was performed. The ultra-structure of resin tags were observed under scanning electron microscope. The results were as follows ; 1) A higher shear bond strengths (33.62 MPa) in group 8% of Cyanate methacrylate to dentin were found, but there were no statistically significancy between Groups (p > 0.05). 2) The higher ratio of cohesive failures mode in group 2, 6, an 10% could be seen than that in any other groups. 3) A shorter resin tags were observed in all experimental groups. This could be resulted that the preventing from the cyanate methacrylate penetrate into dentin owing to reacting it with dentin collagen. Therefore the resin tags were shorter in lengths. Whether the higher bonding strengths of dentin bonding agents can be affected was not been assured with statistic results. The results indicated that the relation between tensile strengths of the dentin adhesives to bovine dentin and resin tags formed into the dentin could not affected. The main reason of increasing the shear bond strength to bovine dentin in experimental groups could not be assured.
Subject(s)
Adhesives , Chemical Industry , Collagen , Dentin , Dentin-Bonding Agents , Ethanol , Tensile StrengthABSTRACT
The purpose of this study was to evaluate the effects of cyanate methacylate on the shear bond strengths to bovine dentin surfaces as a dentin primers. Seven experimental adhesives were made with different mass fraction of Isocyanatoetylmethacrylate (IEM), 40wt% HEMA (Wako Pure Chemical Industries Osaka, Japan), 0.6% camphoroquinone, 0.4% amine and ethanol as balance. dentin bonding agents (0, 2, 4, 6, 8, 10, 12%) were made and applied on the surface of bovine dentin specimens of 7 experimental groups. Shear bond strengths were measured using a universal testing machine (Instro 4466). To identify the ratio and modes of cohesive failures, microscopic examinationn was performed. The ultra-structure of resin tags were observed under scanning electron microscope. The results were as follows ; 1) A higher shear bond strengths (33.62 MPa) in group 8% of Cyanate methacrylate to dentin were found, but there were no statistically significancy between Groups (p > 0.05). 2) The higher ratio of cohesive failures mode in group 2, 6, an 10% could be seen than that in any other groups. 3) A shorter resin tags were observed in all experimental groups. This could be resulted that the preventing from the cyanate methacrylate penetrate into dentin owing to reacting it with dentin collagen. Therefore the resin tags were shorter in lengths. Whether the higher bonding strengths of dentin bonding agents can be affected was not been assured with statistic results. The results indicated that the relation between tensile strengths of the dentin adhesives to bovine dentin and resin tags formed into the dentin could not affected. The main reason of increasing the shear bond strength to bovine dentin in experimental groups could not be assured.