One‐year clinical study evaluating the fast loading protocol – Immediate provisionalization and delivery of definitive prosthesis within 8 weeks

Abstract

Background One requirement for the predictability of implant treatment with immediate loading protocols is high primary stability. Resonance frequency analysis (RFA) and insertion torque (IT) has been proposed to assess this stability with a quantitative method. Aim/Hypothesis To investigate the clinical outcome, marginal bone maintenance and implant survival for implant treatment using the fast loading protocol which include immediate provisionalization and early delivery of the definitive prosthesis. Material and Methods Of 25 patients were treated with 48 Neoss ProActive Tapered implants placed in both maxilla and mandible in healed bone as well as in fresh extraction sockets. Minimum primary stability, (IT > 35 ncm and RFA > 60), for all single implants was established before subjected to immediate (within 48 hours), non-functional, load using screw-retained temporary restorations (single or maximum 2 splinted implants with 2–3 teeth units). Definitive prostheses were delivered within 6–8 weeks from implant placement, based on RFA measurements during early healing phase. IT, RFA, intraoral radiographs, and impressions of implant positions were registered at implant placement. During clinical follow-up RFA was measured at 2, 4, 6 weeks and 6 months from implant placement. Marginal bone level measurements were performed from intraoral radiographs taken at implant placement, 6-, and 12-month follow-up visits. Results 48 implants were subjected to the fast loading protocol. IT was over 40 Ncm for 46 implants. Two implants with IT < 35 Ncm were both splinted to another implant with IT > 50 Ncm, tightening the retention screw with low forces. No implants were lost during the observation period, giving an implant survival rate of 100%. Mean RFA measurements remained stable without any decrease during the initial healing phase, 78.3 ± 4.0 in the mesiodistal direction and 77.6 ± 4.4 in the buccolingual direction at placement and 81.3 ± 3.7 and 80.8 ± 3.6 respectively at 6 months. Radiographic readings showed that at placement the implant platform was at bone level (+0.13 mm). Mean marginal bone remodeling was −0.47 ± 0.38 mm from implant placement to 1 year, −0.49 ± 0.38 mm from implant placement to 6 months, and only 0.01 ± 0.28 mm between 6 to 12 months follow-up. No significant differences could be found for marginal bone remodeling between implants placed in healed bone and those placed in fresh extraction sockets. Conclusion and Clinical Implications Achieving good primary stability (IT of 40 Ncm) with maintained implant stability during initial healing phase can guarantee predictable clinical outcome for patients subjected to a fast loading protocol. Fast loading showed no significant differences in marginal bone loss in the first year of follow-up as compared to other studies investigating the same implant type but followed different surgical and prosthetic protocols.