title: [The effects of remain of residual tooth on retention of post-core crown system].
abstract: This study was aimed to assess the effects of remain of residual tooth on the retention of postpost-core was made,casted and cemented. The post-core was tested at the speed of 10 mm/min on the Instron4302, and the retention force was recorded. Other samples were made and subjected to the test for cohesion of polymethylmethacrylate and metal. The result showed that retention significantly increased with the adding of the residual tooth. When the length of post was longer than 8 mm and 1 mm was added to tooth remain, the difference in retention between the two groups was statistically significant. It was noted that there existed relationships of retention to length of post and tooth remain, of cohesion to length of post and tooth remain, and of frictiion resistence to length of post and tooth remain; moreover, the relevant linear regression equations were obtained. So during the tooth preparation of post-core system, the tooth tissue should be reserved as much as possible.
authors.affiliation: Department of Prothodongtics, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
authors.forename: Iin
authors.initials: I
authors.lastname: Niu
authors.forename: Xinmin
authors.initials: X
authors.lastname: Chen
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wu
authors.forename: Yan
authors.initials: Y
authors.lastname: Yang
authors.forename: Wei
authors.initials: W
authors.lastname: Yao
mesh_terms: D003442:Crowns; D017268:Dental Prosthesis Retention; D003799:Dental Stress Analysis; D006801:Humans; D011176:Post and Core Technique; D014092:Tooth Root