engleski

New method of marginal leakage evaluation

Marginal adaptation of the restorative material to the cavity wall can result with marginal leakage and is described as bacteria, die, radiosotope penetration and may be measured with dissecting microscope or with Scanning electron microscope. A deficiency of these producers is their two- dimensionality because of cutting, grinding or fracturing of specimens. To estimate leakage more precisely is better to use techniques that enable three- dimensional picture. It can be achieved with tehnique of colouring and demineralization of specimens. To evaluate marginal leakage of Class V fillings it is necessary to prepare a cavity of dimensions (3 x 2 x 1.5 mm) where one margin and wall must be in cementum. After preparation, cavity surface should be prepared for adhesive definitive filling, filled and polimerizated. Specimens are then thermocycledfor at least 500 thermal cycles of 1 - minute water baths at 50C and 550C. After that specimens are imersed in acid resistant ink (Rotring ink) for 24 hours. Specimens are thoroughly rinsed and imersed in nitric acid (5% HNO3) for 24 hours. Specimens are finally rinsed and with exavator deprived of definitive filling. Cavity and walls and filling surfaces can be reviewed through dissecting microscope. Advantage of this procedure is the possibility to evaluate all margins and walls at the same time and thus prevent mistakes of linear evaluation.

marginal leakage

nije evidentirano