시효처리와 thermal cycling이 치관전장용 복합레진의 2축굽힘강도에 미치는 영향
EFFECTS OF AGING AND THERMAL CYCLING ON THE BIAXIAL RLEXURE STRENGTH OF VENEERING RESIN COMPOSITES FOR CROWN
정관호, 하일수, 송광엽,
소속 상세정보
정관호 ( Jeong Gwan-Ho ) - 전북대학교 치과대학 치과보철학교실
하일수 ( Ha Il-Soo ) - 전북대학교 치과대학 치과보철학교실
송광엽 ( Song Kwang-Yeob ) - 전북대학교 치과대학 치과보철학교실
KMID : 0362419990370050597
Abstract
This study was performed to evaluate the effect of aging and thermal cycling on the biaxial flexure strength of four commercially available veneering resin composites for crown(Dentacolor : DC, Artglass : AG, Esternia : ET and Targis : TG). Disc specimens were fabricated in a teflon mold giving 12mm in diameter and 1mm in thickness. All samples were divided into 4groups. Group 1 was dried in a dessicator at 25degrees C for 30 days. Group 2 was immersed in distilled water at 37degrees C for 30 days. Group 3 was immersed in distilled water at 65degrees C for 30 days. Group 4 was subjected to 10,000 thermal cycles between 5degrees C and 55degrees C, and the immersion time in each bath was 15 seconds per cycle. Biaxial flexure test was conducted using the ball-on-three-ball method at the cross head speed of 0.5mm/min and fracture surfaces were observed with scanning electoron microscope. The results obtained were summarized as follows ; 1. Weibull modulus values, except for the AG group, decreased after thermal cycling treatment. 2. Biaxial flexure strength values of aging group at 37degrees C were th lowest in all sample groups. Except for the DC group, strength values were significntly decreased for the drying group. 3. After thermal cycling test, the highest value of biaxial flexure strength of 188.8 MPa was observed in the ET group and the lowest value of 73.2 MPa was observed in the DC group. The strength values showed the significant differences in each group (p<0.05). 4. Observation of surfaces after thermal cycling test revealed the ditching in the part f surrounding large fillers.
키워드
Veneering composite resin; Aging; Thermal cycling; Biaxial flexure test
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