Introduction: After tooth loss the alveolar ridge undergoes atrophy. The fixed detachable implant supported prosthesis represents a common treatment for the rehabilitation of completely edentulous jaws. Although the all on four technique has high success rate, but still has many disadvantages such as the presence of a cantilever in the prosthesis.
Objectives: To compare peri-implant soft and hard tissues around 4 mandibular interforaminal implants having tilted posterior implants with posterior cantilevers, versus vertical implants, 2 in the interforaminal region and 2 in the first molar region, without posterior cantilevers.
Material and Methods: 56 implants were placed flapless in the mandibles of 14 edentulous participants. Four implants were placed for every participant. Axial group, 2 implants in interforaminal area and 2 in molar area. Tilted group, 2 anterior vertical and 2 posterior distally inclined implants. Interim screw retained prostheses were immediately loaded after surgery. After 3 months, all participants received fixed detachable metal acrylic resin definitive restorations. A follow-up protocol of 3, 6, and 12 months was scheduled to assess the modified gingival index, modified plaque index, peri-implant probing depth, implant stability, marginal bone level and bone density.
Results: No statistically significant differences were found in peri-implant soft and hard tissues between the axial and tilted implant groups after 1 year.
Conclusion: Placing 4 flapless immediately loaded implants in mandibular edentulous patients that supported full arch fixed restorations provided high implant and prosthodontic success rates whether posterior implants were tilted with posterior cantilevers or vertically aligned without posterior cantilevers.