Survival rate, peri-implant soft tissues and crestal bone loss of implants inserted by flap or flapless surgery in type 2 controlled diabetic patients and immediately loaded with mandibular fixed prosthesis. One year randomized clinical trial

Objectives:The aim of this short-term randomized trial was to evaluate survival rate,peri-implant soft tissues and crestal bone loss of implants inserted by flap or flapless surgery in type2controlled diabetic patients and immediately loaded with mandibular fixed prosthesis
Materials and methods:Twelve completely edentulous patients with controlled typeIIdiabetes mellitus(HbA1c ranged from5to6%)were randomly assigned into two equal groups:Group I(flap surgery)received6implants in the mandible using standardized full-thickness mucosal flap surgery and free hand implant placement;GroupII(flapless surgery)received6implants in the mandible using flapless surgical approach and computer guided implant placement.Implants were immediately loaded with acrylic fixed restoration.Three months later, fixed ceramo- metal restoration was delivered.Implant survival rate, peri-implant soft tissues(plaque index, gingival index, pocket depth and keratinized mucosal width)and crestal bone loss were evaluated at time of implant loading (baseline),3months,6months and12months after loading.
Results:The implant survival rate was94.5%and91.6%in the flap and flapless groups respectively.Without difference between groups (p=.652).For both groups,plaque scores,pocket depth and crestal bone loss significantly increased with time.Gingival scores significantly increased from baseline to 3 months, then significantly decreased thereafter.Keratinized mucosal width significantly increased from baseline to3months for flap group and insignificantly decreased for flapless group.Flap group showed significant higher plaque scores, gingival scores, pocket depth, width of keratinized mucosa and crestal bone loss than flapless groups.
Conclusion:Computer guided flapless surgical approach may be recommended for implants placed in edentulous type2controlled diabetic patients and immediately loaded with mandibular fixed prosthesis as it was associated with favorable peri-implant soft tissue response and crestal bone loss compared to implants placed with flap surgery after one year.