CHEMICAL DEGRADATION OF LIGHT CURED COMPOSITE RESINS IN NAOH SOLUTION

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Journal of the Korean Academy of Pediatric Dentistry 2002;29(3):469-477.
Published online August 31, 2002.

CHEMICAL DEGRADATION OF LIGHT CURED COMPOSITE RESINS IN NAOH SOLUTION

NaOH 용액내에서의 광중합형 복합레진의 화학적 분해

김정란, 정병초, 양규호

전남대학교 치과대학 소아치과학교실 및 치의학 연구소

Abstract

One of the major deficiencies of composite restorative resins is their insufficient resistance to wear. Of the multitude of factors that have been associated with wear, subsurface degradation within the restoration is considered to be one. The aim of this study was to evaluate the resistance to degradation of four commercial composite resins in an alkaline solution. The brands studied were Z100(3M), Clearfil AP-X(Kuraray), Tetric Ceram(Vivadent), Aelit flo(Bisco). 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 sequence of the mass loss was in ascending order by AE, EL, TC, Z100. There was statistically significant difference of mass loss between AE, CL group and TC, Z100 group(p<0.05). 2. The sequence of the degree of degradation layer depth was in ascending order by AE, CL, TC, Z100. But there was no statistically significant difference of degree of degradation layer depth between AE and CL(p<0.05). 3. For the Si concentration, Z100 was the highest of all. 4. The correlation coefficient between mass loss and degradation depth was relatively high(r=0.71 p<0.05).

Key Words: Composite resin, Subsurface degradation, NaOH solution