Maryland-bridge application as a suitable technique to preserve marginal bone level of not-submerged supracrestal implants.

Background: One to 6 months after implant placement is a critical time/period responsible for crestal bone loss that may affect implant osseointegration. The study aims to explore the effectiveness of provisional adhesive Maryland-bridge (AMB) applied to prevent marginal bone level (MBL) around implants placed in edentulous crestal bone in posterior area during osseointegration period.

Methods: Healthy, non-smoker patients (N.=18) were included in the study. Titanium implants were placed nonsubmerged (i.e. tissue-level) with cover screws at gingival level in edentulous crestal bone with flapless technique. Nine patients randomly received an AMB, while 9 patients did not receive any AMB. Each AMB remained in place for 3 months and removed before impression. After 3 months abutments were applied, and provisional resin crowns cemented and definitive metal-ceramic crowns were cemented after 2-3 months. Periapical Rx were taken using paralleling technique before and after implant insertion, at 1, 3 months (pre-loading time) and after 6 months (post-loading time). MBL was evaluated in double-blind on scanned periapical radiographs and assessed at mesial and distal side of implants (M-MBL and D-MBL). Area of bone loss on mesial and distal side of implants (Area-M and Area-D) and Cervical Enamel Junction migration of mesial and distal adjacent teeth were also measured (CEJ-M and CEJ-D). Linear regression models were fitted to evaluate the existence of any significant difference.

Results: Two drop-out was observed in AMB group. A total of 16 patients completed the study. After 6 months, all implants were safe and free from complications. AMB group showed the most stable MBL at 1-6 months, statistically different from non-AMB and resulted in a reduced crestal bone loss from baseline compared to Non AMB group. Area-M and Area-D were not statistically different between the groups. CEJ-M and CEJ-D were stable in both groups.

Conclusions: The use of Adhesive Maryland Bridge to protect non-submerged post-extractive implants is a safe procedure that prevents bone loss around implants and preserve the 3D architecture of crestal bone ridge.