Wear and marginal breakdown of composites with various degrees of cure
Wear and marginal breakdown of composites with various degrees of cure
复制标题
DOI：
10.1177/00220345970760081401
复制
发表时间：
1997-08-01
影响因子：
7.6
通讯作者：
Todd, R
中科院分区：
文献类型：
--
作者：
Ferracane, JL;Mitchem, JC;Todd, R
由于磨损导致的解剖形状丧失被认为是限制后路复合材料临床使用的一个因素。复合材料的物理性能和可能的耐磨性受其固化程度的影响。本研究的目的是不同程度的转换（DC）的复合材料，以测试的假设，耐磨性和边缘击穿可以提高增强固化。配制含有50% Bis-GMA/50%TEGDMA树脂和62体积%锶玻璃（1至2 μ m）与微填充二氧化硅的光固化混合复合材料（Bisco）。在50例无牙颌患者的下颌义齿中，将复合材料放置在钴铬合金牙的两个直径为2.5 mm的圆柱形孔中，替换第一和第二磨牙。将复合材料光固化不同的时间段（在120 ° C下9秒、12秒、25秒、40秒和40秒+10分钟），然后抛光。还测试了微量填充Heliomolar。通过FTIR测量DC（%），并且DC（%）的范围在光固化9秒的55%和光固化40秒的67%之间，然后加热。在基线、6个月、1年和2年时对结石进行评估。由3名观察员独立评估结石模型，以确定总切缘的百分比。用表面光度计测量环氧树脂复制品的磨损。混合复合材料在2年时的磨损范围从光固化9 s时的144 Fun的最高值到光固化40 s后加热时的36 Fun的最低值。在2年时，Heliomolar表现出11 - 16 Fun的磨损。杂化复合材料的固化程度与磨料磨损之间存在很强的负相关性（r（2）= 0.91）。边际击穿是可以忽略不计的混合动力车，并减少了微填充从40%至15%的利润率的热处理。本研究表明，牙科复合材料的耐磨性可以通过提高其转化率来改善。
Loss of anatomical form due to wear has been cited as one factor limiting the clinical use of posterior composites. The physical properties and possibly the wear resistance of composite are influenced by the extent to which it is cured. The aim of this study was to vary degree of conversion (DC) in composites to test the hypothesis that resistance to wear and marginal breakdown could be improved by enhanced curing. A light-cured hybrid composite containing a 50% Bis-GMA/50% TEGDMA resin and 62 vol% of strontium glass (1 to 2 mu m) with microfill silica was formulated (Bisco). Composite was placed into two 2.5-mm-diameter cylindrical holes in Co-Cr teeth replacing first and second molars in the mandibular dentures of 50 edentulous patients. The composites were light-cured for different time periods (9 s, 12 s, 25 s, 40 s, and 40 s + 10 min at 120 degrees C) and then polished. The microfill Heliomolar was also tested. DC (%) was measured by FTIR and ranged between 55% for 9 s of light-curing and 67% for 40 s of light-curing followed by heat application. Impressions were evaluated at baseline, 6 mo, 1 yr, and 2 yrs. Stone casts were evaluated independently by three observers to determine the % of the total margin exhibiting breakdown. Epoxy replicas were measured with a profilometer for wear. Wear of the hybrid composite at 2 yrs ranged from a high of 144 Fun with 9 s of light-curing to a low of 36 Fun with 40 s of light-curing followed by heat. Heliomolar exhibited from 11 to 16 Fun of wear at 2 yrs. There was a strong negative correlation (r(2) = 0.91) between the degree of cure and the abrasive wear of the hybrid composites. Marginal breakdown was negligible for the hybrids, and was reduced for the microfill from 40% to 15% of the margin by heat treatment. This study showed that the resistance to abrasive wear of a dental composite could be improved by enhancement of its degree of conversion.