Title: 1792 - Retrospective Clinical Analysis of Non-Precious Alloy Telescopic Crown Retained Prostheses


Samir Abou-Ayash (Presenter)
zmk Bern

Malin Strasding, University Clinics of Dental Medicine University of Geneva
Thomas Laziok, Medical Center - University of Freiburg, Center for Dental Medicine
Sebastian Patzelt, Medical Center - University of Freiburg, Center for Dental Medicine


Objectives: The objective of this retrospective study was to analyze survival and success rates of removable partial dentures retained by non-precious alloy telescopic crowns (NPATC) and survival of abutment teeth. Contributing factors for survival, success and patient satisfaction were to be analyzed.

Methods: Out of a comprehensive data base, 61 patients with 82 telescopic-crown retained prostheses and 268 abutment teeth with NPATC, returned for a clinical examination (summary table 1). Patients were subdivided into a short term (ST; < 1 year), an intermediate term (IT; 1-3 years) and a long term group (LT; > 3 years). Prosthetic success was defined as a prosthesis that was still in situ without any performed adjustments, except for relining. For statistical analyses Pearsons chi square tests were used. The study protocol was approved by the local ethics committee.

Results: The overall prosthetic survival rate was 100%. The prosthetic success rates in the different groups were 95.2% (ST), 63% (IT) and 46.7% (LT). Abutment tooth survival in the different groups was 100% (ST), 98% (IT), 94.1% (LT). The overall survival rate of abutment teeth was 96.4% (table 2). Most frequent technical complications were veneering fractures (9.76%), followed by fractures of prosthetic teeth (4.88%) and fractures of denture bases (4.88%). Loss of vitality or hypersensitivity of abutment teeth were more frequently observed in prostheses with quadrangular support (17.86%) compared to triangular (7.77%) and linear support (15.8%), p=0.013; the respective area of support showed no statistically significant impact on patient satisfaction (p=0.836). Presence of plaque was associated with an increased tooth loss (p=0.035). Location of prosthesis, type of veneering (full-veneered vs. partially-veneered), number of abutment teeth and vitality of abutment teeth were not associated with higher risks for survival or success.

Conclusions: Non-precious alloys can successfully be utilized for the fabrication of telescopic crowns.


Characteristics Details
Number of Patients n = 61
Observation period [months]
25.2 months ± 16.51
Sex male = 37, female = 24
Mean age [years]
65.59 ± 10.84
Total number of abutment teeth n = 268
Total number of prostheses n = 82
mean number of abutment teeth/ Prosthesis n = 3.56
number of fully veneered/ partially veneered telescopic crowns n = 140/ 128
Group Period (months) Abutment teeth (n) Prostheses (n) Abutment survival (%) Prosthetic survival (%) Prosthetic success (%)
Overall 25.2 ± 16.51 268 82 96.4% 100% 68.3%
Short Term 7.06 ± 3.37 65 21 100% 100% 95.2%
Intermediate 24.87 ± 6.94 152 46 98.4% 100% 63%
Long Term 51.67 ± 12.73 51 15 94.1% 100% 46.7%

Student Presenter

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE