Complications Related to Cantilever Lengths in Implant-Supported Single Crowns

Prosthesis using implant has become a popular modality to treat edentulous patients for the last 35 years. The progress in surface treatment reduces the failure rate and provides better functional and esthetic restorations in dentistry. The earliest form of implant prosthesis was the splinted-fixed type. After full arch and partial edentulous prosthesis began to demon-strate s stable clinical successes rate, single crowns started to be restored with implants.When the implant supported single crown is located most distally in the arch, special biomechanical factors should be considered. Especially when the implant is placed in a more distal position, there will be exposure to tremendous lateral forces resulting in possible complications. The purpose of this study is to analyze the relationship between complications and distance from adjacent teeth to the implant, and to identify the types and frequency of complications. A total of 115 patients charts were investigated randomly from the implant clinic at Ewha WomansUniversity Hospital and Yonsei University Dental Hospital. The patients received an implant supported single crown from 1996 to 2007 and annual afterwards. Patients were grouped according to the pres-ence or lack of complications and the relationship of tooth to implant distance and complications was investigated. Age, sex, and abutment connection type were also analyzed for relationship with complications. The measured data from the two groups were analyzed statistically with SAS version 9.1 (SAS Inc., USA). There were significant statistical differences using logistic analysis (p<0.05) between the tooth to implant distance and complications. The odds ratio was 2.1 and cut off value from maximum value of specificity and sensitivity was 3.39 mm.