The value of alveolar ridge preservation in the context of dental implant therapy

by Gustavo-Avila-Ortiz, DDS, MS, PhD

Tooth extraction is one of the most frequently indicated procedures in dental practice. Clinicians must be aware that, as a direct consequence of tooth loss, a sequence of local biologic events that ultimately lead to dimensional alterations of the hard and soft tissues that constitute the alveolar ridge are inevitably triggered.

Our group recently conducted a meta-analysis of post-extraction dimensional changes affecting the alveolar ridge following unassisted socket healing in humans. Meta-analyses using data from properly executed randomized clinical trials are generally acknowledged as the highest level of scientific evidence. This study corroborated previous findings showing horizontal and vertical alveolar ridge reduction occur naturally, as a direct consequence of tooth extraction.

These dimensional alterations are more pronounced on the corono-facial aspect of the ridge, while more horizontal ridge reduction should be expected in molar sites compared to non-molar sites. The clinical impact of these changes is more critical in the anterior zone. Additionally, facial bone thickness upon extraction seems to be a strong predictor of the extent and magnitude of alveolar bone resorption, as the thicker the facial bone, the lower the amount of ridge  resorption.

In sites that undergo extensive alveolar ridge atrophy, ridge augmentation is often required to correct resulting deformities that interfere with tooth replacement therapy using implant-supported prostheses. Unfortunately, ridge augmentation procedures pose increased risks for complications and patient morbidity, as well as higher expenses and longer treatment times.

However, adequate management of the extraction site provides an opportunity to attenuate or even overcompensate for post-extraction ridge resorption, with the ultimate objective of optimizing patient care. For this purpose, numerous therapeutic strategies have been described and tested in clinical settings, including partial extraction protocols⁴, orthodontic extrusion⁵ and alveolar ridge preservation.⁶

Alveolar ridge preservation (APR) has been defined as a therapeutic intervention carried out immediately after complete tooth extraction with the goal of attenuating the loss of ridge volume⁷. ARP procedures are even indicated for extraction sites that exhibit minimal or no bone damage. They typically consist of the application of a socket filler, usually a bone grafting material, with or without socket sealing⁸, either with a barrier material (e.g., membrane or matrix) or an autogenous soft tissue punch⁹. In spite of technical similarities, ARP is conceptually different from buccal overbuilding techniques¹⁰ or alveolar ridge reconstruction procedures, which are indicated in sites exhibiting significant alveolar bone damage upon extraction¹¹.

Evidence supporting the efficacy and predictability of ARP is ample and robust. This is clearly illustrated in a meta-analysis conducted by our group that analyzed data extracted from randomized clinical trials and demonstrated that ARP renders superior outcomes compared to unassisted socket healing.¹² In fact, over the past two decades, ARP has truly become a game changer in daily clinical practice and should be considered the standard of care in the management of extraction sites that are likely to undergo significant remodeling, whether or not immediate implant placement is performed.¹³

This article was previously published in Academy News.