Is Alveolar Ridge Preservation Necessary in Molar Sites? A Systematic Review.

Purpose: Alveolar ridge preservation (ARP) aims to minimize alveolar bone resorption after extraction. The benefit of ARP in reducing the need for additional bone augmentation procedures to facilitate implant placement has been demonstrated, particularly in single-rooted tooth sites. However, its efficacy in molar sites remains unclear. This systematic review aimed to investigate if ARP in molar sites, compared to spontaneous healing (SH), adequately preserves ridge dimensions to facilitate successful implant placement while reducing the need for additional bone augmentation procedures such as guided bone regeneration (GBR) or sinus floor augmentation (SFA).

Materials and methods: A literature search was conducted using four electronic databases. Randomized controlled trials (RCTs), controlled clinical trials (CCTs), and cohort studies involving adult patients undergoing molar tooth/teeth extraction planned for implant placement and with a minimum follow-up of 3 months were included. Data on horizontal and vertical ridge dimension changes, need for GBR or SFA for implant placement and other implant-related outcomes were collected.

Results: A total of 14 studies were included: eight RCTs, two CCTs, three prospective cohort studies, and one retrospective cohort study. 571 sites were analyzed, with the number of sites in individual studies ranging from 20 to 80. In periodontally sound sockets, the ridge width reduction was less in the ARP groups (range: -1.02 ± 0.88 mm to -2.73 ± 1.68 mm) compared to SH groups (range: -2.36 ± 0.91 mm to -4.44 ± 3.71 mm). A similar trend was noted for ridge height reduction, irrespective of the condition of extraction socket. Moreover, ARP reduced the need for advanced grafting procedures (20.8% for ARP groups vs 47.7% for SH groups), including GBR, SFA and SFA via lateral window approach.

Conclusions: Within the limits of this review, it can be concluded that ARP in molar sites can limit alveolar bone resorption post-extraction and reduce the need for additional bone augmentation procedures as well as the likelihood of requiring SFA via the lateral window approach in maxillary posterior sites.