Three-Dimensional evaluation of marginal bone resorption associated with flap and flapless placement of immediately loaded implants retaining mandibular overdentures with resilient stud attachments. One year randomized controlled clinical trial

Purpose: This study was carried out to evaluate Three-Dimensional marginal bone resorption with flap and flapless placement of immediately loaded implants retaining mandibular overdentures with locator attachments.
Materials and methods: Ten edentulous patients (6 males and four females, with an average age of 59 years) complaining of lack of retention of mandibular dentures received two implants in the canine positions of the mandible using either flap (group 1) or flapless (group 2) surgical approach. All implants were immediately loaded with locator retained mandibular overdentures. Cone beam CT was used to measure Three-Dimensional bone loss at mesial, distal, buccal and lingual surface of each implant. Measurements were made at baseline, six and 12 months later after delivery.
Results: The survival rate was 90% and 100% for flap and flapless groups respectively. For all implant surfaces, flap group showed significant higher bone resorption than flapless group. After 12 months, the highest bone loss occurred at the mesial surface and the lowest bone loss occurred at the buccal surface in the flap group. For flapless group, the highest bone loss occurred at buccal surface and the lowest bone loss located at lingual surface. For all implant surfaces in both groups, marginal bone loss after 12 months was significantly higher than the values after six months.
Conclusion: Within the limitations of this study, the flapless surgical approach is recommended for locator retained mandibular overdentures than the flap approach as it was associated with reduced marginal bone loss after 12 months.