Peri-Implant Health and Esthetic Challenges After Extraction

When replacing a failing tooth with an implant-supported restoration, many surgical and restorative procedures can influence tissue stability, including the timing of the implant placement and restoration placement relative to extraction, partial extraction therapy procedures to minimize bundle bone changes,^3-6 soft-tissue augmentation to enhance volume and quality,^7-9 and the design of the transmucosal prosthetic components to support the soft tissue and protect the bone via critical/subcritical contour, acute versus obtuse emergence angle, and abutment length.^10-14 When tooth extraction does not leave an environment suitable for immediate implant placement, clinicians routinely perform socket preservation procedures, more appropriately referred to as alveolar ridge preservation procedures, to compensate for the expected biologic impact associated with bundle bone changes.^15,16The goal of alveolar ridge preservation is to reduce the complexity of future implant placement and esthetic problems associated with extraction-induced bone loss. Although the research supporting the use of alveolar ridge preservation is extensive, few studies assess the long-term results of implant treatment at these sites. However, some more current studies clearly document the failure of these procedures in achieving complete preservation of the ridge dimension. Instead, they have found that some degree of remodeling generally occurs that results in the need for additional bone and soft-tissue augmentation at the time of implant placement.^17-19 Considering these findings and the associated costs of repeated bone grafting procedures, the question of whether or not alveolar ridge preservation procedures should be routinely performed is increasingly posed. In response to the question of whether or not ridge preservation procedures are potentially "overtreatment," Marda and colleagues provide evidence to support ridge preservation while also highlighting some of the reasons why there is debate regarding its routine application.²⁰

Some studies, even those that are supportive of ridge preservation, have presented some, albeit limited, evidence that placing implants into biomaterials may be associated with a higher risk for peri-implantitis in some clinical scenarios (eg, mandibular grafted sockets, grafted type III sockets).²¹ It is also important to recognize that ridge preservation procedures do not accelerate bone healing or improve the quality of bone. Depending on the graft material used, they may in fact interfere with new bone formation.^22,23 The term "perigraftitis" was coined by Do and Cobb in a case report that recognized a risk for peri-implant complications associated with the placement of implants in sites that were previously grafted with low substitution products.²⁴

There is limited literature focusing on the financial implications of multiphase augmentation procedures for patients or the possibility that peri-implant complications may be associated with prior alveolar ridge preservation procedures. Although many factors may contribute to peri-implant diseases, including the patient's systemic health, microbiome, and immune response, as well as surgical or restorative issues, the increasing incidence of peri-implant disease should motivate us to analyze our protocols to better understand the risks associated with our clinical decisions. Because the majority of alveolar ridge preservation and delayed implant placement studies document short-term follow-up periods, we should question whether late complications such as peri-implantitis could be linked to the "overuse" of alveolar ridge preservation procedures.

Advocating for more careful case selection for ridge preservation is important. As stated in some of the previously referenced studies, we need to define in what scenarios alveolar ridge preservation will improve treatment outcomes when compared with unassisted socket healing. Clinical situations that may not warrant ridge preservation include those involving a thick bone morphotype, intact bone walls, a favorable relationship between the bone crest and soft-tissue margin, and conservative extractions. Unnecessary ridge preservation procedures may also be avoided through the identification of cases that may be better treated with immediate implant placement with simultaneous augmentation to support the bone and soft tissues. Although there are numerous factors that can contribute to bone loss following tooth extraction and to bone loss around implants (eg, peri-implantitis), when treatment planning implant-based rehabilitations, clinicians should try to "keep it as simple as possible whenever possible." We have the responsibility of qualifying that every procedure, in this case alveolar ridge preservation, will reduce the future treatment complexity and improve the outcome while being sensitive to the long-term impact of our decisions on implant survival and success.

Sonia Leziy, DDS
Periodontist
Nanaimo, British Columbia, Canada