Author/Editor		Kopač, I
Title		Reprodukcija hrapavosti obrušenega zoba na kovinskem ulitku po tehnoloških postopkih
Translated title		Surface roughness reproducilibity of the prepared tooth on the metal cast following different technological procedures
Type		članek
Source		Zobozdrav Vestn
Vol. and No.		Letnik 57, št. 5
Publication year		2002
Volume		str. 135-40
Language		slo
Abstract		The use of coarse diamond burs for tooth preparation causes a rough dentinal surface (gashes and scratches), which can prevent the exact fit of the crown on the prepared tooth. Surface roughness is reproduced on the metal casting following different technological procedures: impression, stone working cast, wax pattern, metal cast. In the study, the reproducibility of surface roughness after individual technological procedures, from the impression to the metal cast, was investigated using scanning electron microscopy and surface profilometry (Taly Surf). SEM images demonstrate roughness but do not define its dimensional values. The results of 10 measurements show that the average values for Ra are reduced by 2 micro m in the metal casting, while those for Rt decline from an initial value of 40 micro m to a final value of 30 micro m. Standard errors are below 0.4 micro m for Ra and below 2 micro m for Rt. These values demonstrate uniform roughness and precision of the technological procedures used. To improve the fit of the crown, additional surface treatment of coarse cut dentine is needed, especially in the gingival area of chamfer or shoulder preparations.
Descriptors		DENTAL CASTING TECHNIQUE DENTIN DENTAL CAVITY PREPARATION MICROSCOPY, ELECTRON, SCANNING