Ridge preservation for implant therapy: a review of the literature

Abstract

Healing of the extraction socket after tooth removal involves retention of the blood clot followed by a sequence of events that lead to changes in the alveolar process in a three dimensional fashion. This normal healing event results in a minimal loss of vertical height (around 1 mm), but a substantial loss of width in the buccal-lingual plane (4-6 mm). During the first three months following extraction that loss has been shown to be significant and may result in both a hard tissue and soft tissue deformity affecting the ability to restore the site with acceptable esthetics. Procedures that reduce the resorptive process have been shown to be predictable and potentially capable of eliminating secondary surgery for site preparation when implant therapy is planned. The key element is prior planning by the dental therapist to act at the time of extraction to prevent the collapse of the ridge due to the loss of the alveolus. Several techniques have been employed as ridge preservation procedures involving the use of bone grafts, barrier membranes and biologics to provide a better restorative outcome. This review will explore the evidence behind each technique and their efficacy in accomplishing site preparation. The literature does not identify a single technique as superior to others; however, all accepted therapeutic procedures for ridge preservation have been shown to be more effective than blood clot alone in randomized controlled studies.

Keywords: Bone grafts; guided bone regeneration; guided tissue regeneration; implant site preparation; ridge preservation..

Fig. (1)

Extraction site defect 6 months after tooth removal without ridge preservation. Note buccal depression and loss of vertical height at site #10.

Fig. (2)

Esthetic defect caused by tooth loss without ridge preservation requiring guided bone regeneration to adequately place an implant at the #10 site for an acceptable outcome (occlusal view).