Telescopic Crowns on Implants and Teeth: Evaluation of a Clinical Study After 8 to 12 Years

Purpose: To evaluate the outcome of a clinical study on telescopic-crown-retained removable dental prostheses (TCR-RDPs) on implants or implants and teeth after 8 to 12 years. Materials and Methods: Between 1999 and 2002, 39 (41 arches) patients received implant- or combined tooth-implant-supported TCR-RDPs in the maxilla and/or mandible. One-stage surgery was performed, and after a conventional healing period, TCR-RDPs were inserted. Thirty-one patients (33 prostheses) were available for annual follow-up investigations with a standardized protocol from 2010 until 2013. Cumulative survival and success of the abutments were estimated using the Kaplan-Meier method, and a Cox regression model was used to identify potential predictors for abutment complications. Patients' oral health-related quality of life (OHRQoL) was measured by means of the Oral Health Impact Profile (OHIP). Results: After a mean observation period of 11.3 ± 1.1 years, all restorations were still functioning successfully. Two implants and 10 abutment teeth were lost, leading to significantly different implant and tooth survival rates of 97.6% (SE ± 1.7%) and 81.8% (SE 5.3%; P = .007). Implants placed in the mandible and those in the group with a higher number of abutments (five to six vs two to four) showed higher success rates. The success rates of abutment teeth were not influenced by location (mandible vs maxilla) or number of abutments (five to six vs two to four). Conclusion: Implant- or combined tooth-implant- supported TCR-RDPs provided a satisfying treatment option for patients with severely reduced dentition in the long term. Due to the small sample size, the results presented should be interpreted with caution. Keywords: complication, double crown, implant-retained prosthesis, removable dental prosthesis, survival rate, telescopic crown