Vachiramon Viracha, Vargas Marcos A, Pashley David H, Tay Franklin R, Geraldeli Saulo, Qian Fang, Armstrong Steven R
Department of Conservative Dentistry and Prosthodontics Faculty of Dentistry, Srinakharinwirot University Sukhumvit 23, Wattana District, Bangkok 10110, Thailand.
J Dent. 2008 Mar;36(3):178-85. doi: 10.1016/j.jdent.2007.11.011. Epub 2008 Jan 31.
Application of an acidic oxalate solution forms calcium oxalate within dentinal tubules and has been used to desensitize dentin and may also improve performance by reducing internal dentin wetness during bonding. The hypothesis tested was that oxalate restriction of dentinal fluid transudation when using an etch-and-rinse two-step adhesive will improve microtensile bond strength (muTBS) and reduce nanoleakage.
Occlusal dentin of 60 human molars were bonded (Adper Single Bond Plus, 3M ESPE) while one-half of each tooth received either a liquid (SuperSeal, Phoenix Dental) or gel (BisBlock, Bisco) oxalate treatment after acid etching. The restored teeth were placed under pulpal pressure for 3 months before forming cylindrical dumbbell specimens for muTBS and failure pathway determination. Additional teeth were prepared and stored in a similar manner for transmission electron microscopy (TEM) examination of nanoleakage after tracer immersion.
The mean bond strength in the group with oxalate liquid and the control group was 27.06+/-7.14 and 36.18+/-9.07 MPa, respectively, and for the gel form of oxalate was 25.34+/-13.09 and 33.09+/-14.25 MPa, respectively. The control groups were significantly stronger than either oxalate group using t-tests (liquid p<0.00001; gel p=0.0032) or Weibull (liquid p=0.0002; gel p=0.0029) statistics. Oxalate groups also demonstrated more adhesive failure modes and nanoleakage.
Under the conditions of this study, the application of oxalate with an etch-and-rinse two-step bonding system produced significantly lower long-term muTBS and enhanced nanoleakage.
应用酸性草酸盐溶液可在牙本质小管内形成草酸钙，已被用于牙本质脱敏，并且在粘接过程中通过减少牙本质内部湿度也可能改善粘接性能。所检验的假设是，在使用酸蚀冲洗两步法粘接剂时，草酸盐对牙本质液渗出的限制作用将提高微拉伸粘接强度（μTBS）并减少纳米渗漏。
对60颗人类磨牙的咬合面牙本质进行粘接（Adper Single Bond Plus，3M ESPE），同时每颗牙齿的一半在酸蚀后接受液体（SuperSeal，Phoenix Dental）或凝胶（BisBlock，Bisco）草酸盐处理。修复后的牙齿在牙髓压力下放置3个月，然后制成圆柱形哑铃形标本用于测定μTBS和失效途径。以类似方式制备额外的牙齿并储存，用于在示踪剂浸入后进行纳米渗漏的透射电子显微镜（TEM）检查。
草酸盐液体组和对照组的平均粘接强度分别为27.06±7.14和36.18±9.07MPa，草酸盐凝胶组分别为25.34±13.09和33.09±14.25MPa。使用t检验（液体p<0.00001；凝胶p=0.0032）或威布尔分析（液体p=0.0002；凝胶p=0.0029）统计学方法，对照组均显著强于任一草酸盐组。草酸盐组还表现出更多的粘接失败模式和纳米渗漏。
在本研究条件下，在酸蚀冲洗两步法粘接系统中应用草酸盐会导致长期μTBS显著降低并增加纳米渗漏。
