COMPARATIVE STUDIES ON THE RETENTIVE VALUES OF VARIOUS DENIAL CEMENTS USED TO RETAIN ORTHODONTIC BANDS

교정용 BANDS 접착에 사용되는 각종 치과용 시멘트의 유지력에 관한 비교 연구

The purpose of this study was to compare the retentive values of various dental cements used for cementing the orthodontic bands on the teeth. Sound freshly extracted human premolar teeth were selected for the study. Eleven commercial dental cements (Zinc phosphate, reinforced Zinc-oxide eugenol, Carboxylate and Glass ionomer cements) were handled under standardized conditions. All cemented speciments were then kept in a thermostatic humidor cabinet regulated at $23{\pm}2^{\circ}C$ and more than $95\%$ relative humidity and tested after 24 hours and 1 week each. The force required to remove the cemented orthodontic bands from the teeth was determined on an Instron Universal Testing Machine using a modified specimen holding device with a cross-head speed of 0.20mm/min. The results obtained were as follows: 1, The retentive values of the band cemented with zinc phosphate cements and carboxylate cements were considerably higher than those of the reinforced zinc oxide-eugenol and glass ionomer cements. 2. There was no significant difference between the retentive value of carboxylate cements as compared with zinc phosphate cements. 3. The retentive value of the reinforced zinc oxide eugenol cements was lowest all of the coements. The retentive values expressed for all cements up to at least one week were highly but no significant difference was found between the 24-hour and 7 day time intervals.