PROSTHETIC RECONSTRUCTIONS AND REFERRING IMPLANT SURVIVAL IN A POSTGRADUATE PROGRAM: A RETROSPECTIVE STUDY
Figure 3. The implant survival was not significantly different between the upper and lower jaw
3. Results 3.1. Number of patients Data of 819 patients, 420 women and 399 men were available. The mean age at the time of implant placement was 62.3 ± 11.6 years. 507 patients( 62 %) were > 60 years old. The observation time ranged from 1 to 8 years( mean 4.7 ± 1.8 years). Altogether 2337 implants were placed and 1133 related ISRs fabricated during the 6 years of implant placement. The average number of implants per patient was 2.9. 3.2. Number of implants The distribution of the implants within the jaws was equal in the maxilla and mandible with exception of the canine FDI-positions 43 and 33 which was 6 times higher( Fig. 1). Partially dentate patients received totally 948 implants( 40.6 %) compared to 1389( 59.4 %) in the edentulous ones( Table 1). The graduate students themselves placed 80 % of the implants under guidance and supervision in the context of their education program. 10 % of these implants were inserted in patients that were selected for the training in the undergraduate student course. The remaining 20 % of the implants were placed by the program director and instructors while the graduate-students took the role of the assistant nurse. 3.3. Number of reconstructions The number of implants supporting fixed and removable ISR was 1053( 45.1 %) and 1284( 54.9 %), respectively. The percentage distribution of implants per ISR exhibited 337 / 337 SCs( 14.4 %), 422 / 190 FDPs( 18.1 %), 294 / 54 IBs( 12.6 %), 374 / 198 RDPs
( 16.0 %) and 910 / 354 Bar-IODs( 38.9 %)( Table 2). While the absolute and relative number of CAD / CAM fabricated removable ISR increased from 7 % to 64 %, the proportion of ZrO2-based fixed ISR varied between 15 % and 55 % without a clear trend during the observation time( Table 3). 3.4. Implant survival Thirty-one implants were lost resulting in a cumulative survival rate( CSR) of 98.6 % after 8 years. Twelve implants failed before loading while 19 implants were lost 1 to 4 years after loading( Table 4). Totally 12 implants in 8 patients were lost before functional loading. These patients were between 51 and 79 years old, all non-smokers and without significant general health problems. Eight( of 12) implants were located in the mandible( 7 interforaminally, one at FDI position 36). One woman suffered from chronic osteoporosis that was treated with an oral bisphosphonate( Fosamax 10mg / day, MSD Merck Sharp & Dohme AG, Luzern, Switzerland) and showed no problems after replacement of the failed implant. Another female lost the first three interforaminally positioned implant and the second two implants, as well. She had no risk factors and was finally treated with a complete lower denture without implants. Out of a total of 19 implants lost after functional loading 15 implants were located in the maxilla. Detailed information about the restorations and the patients are shown in Table 5. No statistically significant difference was observed for the survival rates between the prosthetic reconstructions( Table 2, Fig. 2). Further analysis revealed no difference comparing fixed vs. removable ISRs, implants with vs. without GBR or SFE, splinted vs. non-splinted ISRs and ISRs in the upper vs. lower jaw( Fig. 3).
228 STOMA. EDUJ( 2016) 3( 2)