A STUDY ON THE SHEAR BOND STRENGTH OF LUTING GLASS IONOMER AND DENTIN TREATED WITH CALCIUM SOLUTION

칼슘수용액으로 처리한 상아질과 합착용 글래스아이오노머의 전단결합강도에 관한 연구

The objective of this paper was to evaluate the shear bond strength of luting glass ionomer cement with defferent calcium based solution treatment on dentin surface. 120 extracted human teeth were classified into 12 group based on presence of smear layer on dentin surface and type of treatment solution. Smear layer remove on dentin surface was done using 6% citric acid for 60 seconds. Five different dentin surface treatment solutions(calcium acetate, calcium carbonate, clacium chlorided, calcium hydroxide, and calcium phosphate) were evaluated in this study. After surface modification, metal ring(inner diameter : 3mm, depth : 1mm) was placed to expose the same dentin surface area and inner space was filled with luting glass ionomer cement according to the recommended procedure for stadard clinical procedure. The shear bond strength of glass ionomer cement was determined after 24 hours. SEM was used for the evaluation of the surface morphologic changes and EDAX analysis was done for determination of the change of the calcium contents of treated dentin. Follwing conclusion can be drawn : 1. In the group of the dentin surface with smear layer, the calcium carbonate solution was the most effective for the increase of the clacium content and the shear bond strength of glass ionomer cement to dentin surfaces. 2. In the group of the calcium carbonate treated dentin with msear layer, the shear bond strength was increased twice compared to the control group and cohesive failure mode was observed. 3. The shear bond strength of cement was increased significantly be the removal of smear layer using 6% citric aicd. However, additional calcium solution treatments were not effective for further bond strength increase. 4. The shear bond strength of cement was significantly improved by both of the removal of smear layer and the calcium solution treatment, and the former was more effective for bond strength improvement. 5. The smear layer removed/calcium solution treated groups showed dentinal tubule obstruction and crystal attachment in SEM evaluation. However, the shear bond strengths of these groups were not increased compared to the smear layer removed/no dentin treatment group.