The examination of the surface properties (by SEM)and the fit of marginal zone (by stereomicroscope)of the galvano crowns exposed to thermal cycling and compressive force

Galvano crowns, owing to being biocompatible with oral tissues at the gold of its content, being found effectives of toxic in the part of alloys which is used in the substructure materials, have been used in the substructure of prothetic restoration in the dentistry. Galvano copings which is obtained with electrolyt deposition of gold to a surface, beside being fairly well of marginal fit, also because of esthetical advantage it has been preffered as alternative to the restorations which is obtained with conventional methods. At literature compings which is done usually with being utilized the marginal fit of galvano crowns which has been two different prepapation type, with galvano copings which have been differentt type preparation Co-Cr copings which are obtained with sintered method with laser and it hasn?t been found studies about with marginal fit of copings which is covered the gold on Co-Cr which is obtained with laser sintered method. At this study; it was utilized the surface traits and marginal fit before and after of process which have been exposed to thermal cycling and compressive force of galvano copings which have been done on the ninety amount stainless steel model which have different types of preparation, Co-Cr copings which have been obtained with laser sintered method and copings which are covered gold on Co-Cr which has been obtained with laser sintered method. According to results which are found, the galvano copings which have Chamfer type of preperation showed the most low worth at the gap measurements which have done before cementation(24.468±5.828 ?m). The lowest marginal gap measurements were obtained at the copings which have Deep Chamfer preparation From the Co-Cr copings which are obtained with laser sintered (60,430±10.674 ?m). The lowest marginal gap worths were obtained at the copings which have Deep Chamfer preparation at the measurements which were done before cementation of copings which were covered gold on Co-Cr was obtained with laser sintered method(58,905±6.902 ?m). In the measurements which were done before cementation, marginal gap worths at the copings which have Knife Edge preparation was found high in proportion to the copings which have Chamfer and Deep Chamfer preparation. Key words: Galvano crowns, Thermal cycling, Marginal fit, Compressive force