Computer guided implant installation and immediate loading of cross-arch fixed dental prosthesis- a 5-year prospective clinical study

Background Prosthetically driven implant placement, high primary implant stability and lack of micro-movements are considered some of the main factors necessary for achieving predictable treatment outcomes with immediately loaded implant-supported cross-arch fixed dental prostheses (FDP). Aim/Hypothesis To evaluate 5-year clinical and radiographic outcomes of immediately loaded implants placed in edentulous or partially edentate patients with terminal dentition using computer-assisted template-guided surgery to support a cross-arch screw-retained fixed dental prosthesis. Material and Methods Healthy patients aged 18 years or older at the time of implant placement, in need to be restored with an immediately loaded implant-supported screw-retained cross-arch fixed dental prosthesis in the mandible or maxilla were included in the present study and treated using computer-assisted template-guided surgery (NobelGuide, Nobel Biocare). In order to be immediately loaded implant sites were prepared and an insertion torque ranging between 35–45 Ncm in the mandible and 45–55 Ncm in the maxilla was applied. A prefabricated screw-retained temporary prosthesis was delivered the day of the surgery. The evaluated outcomes were- implant cumulative survival rate (CSR), prosthesis survival, any technical and biologic complications, and peri-implant marginal bone level changes. Results At 5 years follow-up, four patients dropped out. 66 patients (44 females and 22 males) with mean age 66.2 years received 356 implants to support 68 cross-arch screw-retained fixed dental prostheses. 7 implants failed in six patients, resulting in a CSR of 98.1%. After an initial mean marginal bone loss of 1.09 ± 0.38 mm, slightly marginal bone loss was reported with time, resulting in a mean marginal bone loss of 1.62 ± 0.41 mm at the 5-year follow-up. Two definitive prostheses failed resulting in CSR of 97.1%. Five implants (1.4%) showed a mean mesio-distal peri-implant bone loss greater than 3.0 mm with a spot bleeding on probing at the 5-year follow-up and received nonsurgical. After the treatment the bone stopped receding and the soft tissue remained stable. No other biological complications occurred. Conclusions and Clinical Implications Computer-assisted template-guided implant placement is a valid treatment concept for the cross-arch rehabilitation with immediately loaded prefabricated screw-retained fixed dental prosthesis. In the present study, the substantial deviations in three-dimensional directions reported in the literature between virtual planning and the final intraoral implant position, did not produce any clinically relevant drawbacks.