AN EVALUATION OF CHEMICAL DEGRADATION OF LIGHT-CURED RESTORATIVE COMPOSITES

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Journal of the Korean Academy of Pediatric Dentistry 2003;30(3):530-539.
Published online August 31, 2003.

AN EVALUATION OF CHEMICAL DEGRADATION OF LIGHT-CURED RESTORATIVE COMPOSITES

광중합 복합레진의 화학적 분해 평가

양규호, 김훈주, 최남기

전남대학교 치과대학 소아치과학 교실 및 치의학연구소

Abstract

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 Charisma, Filtek P 60, Palpique Estelite, and Spectrum. Preweighed discs of each brand were exposed to 0.1N NaOH solution at 60℃. After 2 weeks they were removed, neutralized with HCl, washed with water and dried. Resistance to degradation was evaluated on the basis of following parameters: (a) mass loss(%) - determined from pre-and post-exposed specimen weights; (b) Si loss(ppm) - obtained from ICP-AE analysis of solution exposed to specimens; and (c) degradation depth(μm) - measured SEM and CLSM from polished circular sections of exposed specimens. The results were as follows: 1. The sequence of mass loss was in descending order by Palpique Estelite, Filtek P 60, Charisma, and Spectrum. 2. The sequence of the degree of degradation layer depth was in descending order by Filtek P 60, Charisma, Palpique Estelita, and Spectrum. 3. The sequence of the Si loss was in descending order by Chrisma, Spectrum, Palpique Estelite, and Filtek P 60. 4. The correlation coefficient between mass loss and degradation layer depth was relatively high(r=0.704, p<0.05). 5. When observed with SEM, destruction of bonding was observed between resin matrix and filler. 6. When observed with CLSM, degradation layer depth of composite resin surface was observed.

Key Words: Composite resins, Subsurface degradation, Resistance to degradation