Clinic of Dentistry, University of Novi Sad, Serbia.
Dent Mater. 2010 May;26(5):449-55. doi: 10.1016/j.dental.2009.11.160. Epub 2010 Mar 1.
To reduce the effect of stresses due to volumetric shrinkage the authors propose an incremental technique for placing composite restorations.
The goal of the method is to reduce the volume of the resin that is polymerized and eliminate a stress singular point in the resin that is positioned at the geometric center of the cavity. This is achieved by a two step type incremental technique. In the first step the resin is placed in the cylindrical cavity with a metal pin embedded in the middle of the composite restoration. After polymerization, the metal pin is removed and the cylindrical hole is filled with the second layer of composite. Finally, the second layer in the center of the composite restoration is polymerized.
This study confirmed that the proposed incremental type placement technique reduces marginal debonding.
The main hypothesis is that the elimination of a stress singular point at the center of the restoration results in the reduction of stresses at tooth-composite interface and therefore improve the marginal adaptation (reduces length of the contraction gap at tooth-composite interface).
为了减少因体积收缩而产生的应力影响，作者提出了一种用于放置复合修复体的增量技术。
该方法的目的是减少聚合的树脂体积，并消除位于腔几何中心的树脂中的应力奇点。这通过两步增量技术来实现。在第一步中，将树脂放置在带有金属销的圆柱腔中，该金属销嵌入在复合修复体的中间。聚合后，取出金属销并用第二层复合材料填充圆柱孔。最后，聚合复合修复体中心的第二层。
本研究证实，所提出的增量式放置技术可减少边缘脱粘。
主要假设是消除修复体中心的应力奇点会降低牙-复合界面的应力，从而改善边缘适应性（减少牙-复合界面处的收缩间隙长度）。
