HYDROLYTIC DEGRADATION OF DENIAL COMPOSITE RESINS

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Journal of the Korean Academy of Pediatric Dentistry 2000;27(2):370-378.
Published online May 31, 2000.

HYDROLYTIC DEGRADATION OF DENIAL COMPOSITE RESINS

수종 치과용 복합레진의 가수분해

양규호, 김정란

전남대학교 치과대학 소아치과학교실 및 치의학 연구소

Abstract

The composite restorative resins have their insufficient resistance to wear. The subsurface degradation within the restoration is considered to be associated with wear. The aim of this study was to evaluate the resistance to degradation of six commercial composite resins in an alkaline solution. The brands studied were Clearfil APX(Kuraray), Heliomolar(Vivadent), Surefil(Dentsply), TPH(Dentsply), Tetric Ceram(Vivadent), and Z100(3M). Preweighed discs of each brand were exposed 0.1N NaOH solution at 60℃. After 14 days they were removed, neutralized with HCL, washed with water and dried to constant mass at 60℃. Resistance to degradation was evaluated on the basis of the following parameters: (a) mass loss(%) - determined from pre-and post-exposure specimen weights; (b) Si loss (ppm)-obtained from ICP-AE analysis of solution exposed to specimens; and (c) degradation depth(μm) - measured microscopically (SEM) from polished circular sections of exposed specimens. The results were as follows: 1. The mass loss was in descending order by Z100, TC H, S, CL, TPH and in the range of 0.45~3.64% 2. The degradation layer depth was in descending order by H, Z100, S, TC, TPH, CL and in the range of 10.85~73.38μm 3. For the Si concentration, Z100 was the highest of all 4. The highly significant correlation(r=0.81, p<0.05) was observed between mass loss and degradation depth. 5. Under scanning electronmicroscopy, the degradation of connection between resin matrix and fillers was observed 2 weeks after soaking in NaOH solution.

Key Words: Composite resins, Subsurface degradation, Alkaline sulution