보철용 크라운/어버트먼트 갭이 표면적합도에 미치는 영향

Abstract

Fit of a restoration and its cementation procedure is crucial to both its short and long term prognosis. Marginal fit is affected by many variables during the fabrication process. These variables, being intrinsic properties of the materials or the clinical technique used, can cause changes in the size and shape of the definitive restoration. Even if all variables are controlled carefully, the seating of a restoration can still be affected due to insufficient space for the luting agent. The use of die spacer can reduce the elevation of a cast restoration of a prepared tooth, decreased seating time, improve the outflow of excess cement, and lower the seating forces. The purpose of this study was to evaluate the marginal fidelity according to die spacer application times and measurement site. Casting alloys were prepared and fabricated using non-precious metal at 950℃. Specimens are divided into four groups: I(die spacer painted casting for wax pattern), Ⅱ(die spacer non painted casting for wax pattern), Ⅲ(die spacer painted casting for resin pattern) and Ⅳ(die spacer painted casting for resin pattern). The specimens were cut and polished for marginal gap observation. The marginal gap was observed using scanning electron microscopy (SEM). These results are as follows : 1.From SEM observation, The marginal fidelity of die spacer painted specimens was higher than that of die spacer non painted specimens. 2.Casting for wax pattern, the gap size at the top decreased as die spacer application times increased, indicating the good marginal fidelity for abutment/crown. 3.Casting for resin pattern, the gap size of die spacer painted specimens at the top decreased than die spacer non painted specimens about 3~4 times.