Immediately loaded implants simultaneously placed in fresh extraction and healed sites supporting four‐implant‐supported fixed mandibular prostheses using the all‐on‐4 concept: A 5‐year prospective study

OBJECTIVES To evaluate the peri-implant marginal bone level for immediately loaded implants placed simultaneously in both fresh extraction sites (FES) and healed sites (HS) supporting a 4-implant supported mandibular fixed prosthesis (4-ISFMP) using the all-on-4 concept. MATERIAL AND METHODS A 5-year prospective study was conducted in 24 patients (96 implants) treated with 4-ISFMP including fifty-five implants inserted in FES and 41 implants in HS. At implant placement (baseline) and at the 1st , 3rd and 5th year follow-up examinations, peri-implant marginal bone level was evaluated radiographically and compared between placement in FES and HS. Marginal bone loss was calculated as the difference of the marginal bone level evaluated at the follow-up periods. Additionally, implant and prosthesis survival rates as well as the presence of peri-implant mucositis (bleeding on probing+[BOP]) and peri-implantitis (BOP+ >2mm MBL) were evaluated. RESULTS 22/24 patients with 88/96 implants (dropout rate: 8.3%) were continually followed for 5 years (survival rate: 100%). Radiographically measured marginal bone level differed significantly between FES and HS at implant placement (1.46±0.80mm vs. 0.60±0.70mm; p 0.99) and the 3- to 5-year period (p=0.082). At the 5-year follow-up evaluation, no implant/prosthesis failed (100% survival) and peri-implant mucositis and peri-implantitis were noted in 41.2% and 11.7% at patient level and in 17.6% and 4.5% at implant level, respectively. CONCLUSION Implants placed in FES showed a prolonged peri-implant remodelling process but provided for similar peri-implant marginal bone levels as implants placed in HS at the 5-year evaluation for immediately loaded 4-ISFMP.