Wickersham G T, Seale N S, Frysh H
Department of Pediatric Dentistry, Baylor College of Dentistry, Dallas, Texas, USA.
Pediatr Dent. 1998 Sep-Oct;20(5):336-40.
This study compared the fracture resistance and color stability of two commercially available, preveneered stainless-steel crowns before and after four sterilization techniques.
Thirty-five crowns from each of two manufacturers were divided into five groups. Four groups were sterilized twice using one of the following techniques: steam autoclave at both 121 degrees C (15 PSI) for 20 min and 132 degrees C (30 PSI) for 8 min; Chemiclave with formaldehyde at 132 degrees C for 20 min; and 2% gluteraldehyde for 10 h. The fifth group from each manufacturer was the control. Color of facings was measured before and after each sterilization in triplicate using a colorimeter, and the variance of each color parameter was analyzed for significance. Fracture resistance was measured for each group and differences between the control and experimental groups analyzed for significance.
The results of this study show that high heat and chemical sterilizations have little effect on color and fracture resistance of the preveneered stainless-steel crowns. Student's t test analysis revealed a significantly decreased resistance to fracture with Kinder Krowns sterilized in 2% gluteraldehyde. Chemiclave sterilization caused the most negative color change in all three color parameters measured for both types of crowns.
As neither steam technique produced significant changes in fracture resistance or color changes that were clinically detectable, the results of this study indicate that the two steam techniques tested can be used by clinicians to sterilize either Kinder Krowns or Nu Smile preveneered stainless-steel crowns.
本研究比较了两种市售预成不锈钢冠在四种灭菌技术前后的抗折性和颜色稳定性。
将两个制造商提供的各35个牙冠分为五组。四组使用以下技术之一进行两次灭菌：在121℃（15磅/平方英寸）下蒸汽高压灭菌20分钟，以及在132℃（30磅/平方英寸）下蒸汽高压灭菌8分钟；使用甲醛在132℃下化学灭菌20分钟；以及使用2%戊二醛浸泡10小时。每个制造商的第五组作为对照组。使用色差仪在每次灭菌前后对牙面颜色进行三次测量，并分析每个颜色参数的方差是否具有显著性。测量每组的抗折性，并分析对照组和实验组之间的差异是否具有显著性。
本研究结果表明，高温和化学灭菌对预成不锈钢冠的颜色和抗折性影响很小。学生t检验分析显示，用2%戊二醛灭菌的Kinder Krowns牙冠的抗折性显著降低。化学灭菌在两种牙冠测量的所有三个颜色参数中导致了最明显的颜色变化。
由于两种蒸汽技术在抗折性或临床上可检测到的颜色变化方面均未产生显著变化，本研究结果表明，临床医生可以使用所测试的两种蒸汽技术对Kinder Krowns或Nu Smile预成不锈钢冠进行灭菌。
