Reasons Why Dental Implants Fail

Empirical research studies continue to correlate implant complications and failures to three factors: the implant system, patient, and dentist. Implant system failures include poor design of the implant body, insufficient number of implants, screw loosening, large microgap, abutment/implant precision, armamentarium, and implant surface. Patient factors involve variables such as genetic susceptibility, immune system, parafunctional habits, preexisting and postoperative medical conditions, self-care, recall compliance, physical impairment, and smoking.¹³Dental practice factors may include preoperative, operative, postsurgical, and restorative. Preoperative factors include poor quality or quantity of soft and soft tissues, inadequate preliminary procedures, occlusal relationships, and treatment planning. A recent systematic review and meta-analysis in the Journal of Periodontology conducted by Bassir et al found early placement of dental implants (complete soft tissue coverage) had similar postsurgical clinical outcomes when compared to immediate placement after extraction and delayed placement of dental implants. However, long-term stability of hard tissues surrounding the dental implant were greater with early placement than immediate placement of dental implants.⁵⁴Operative factors include excessive drill speed and pressures, frictional heat, insufficient irrigation, inappropriate bioengineering, trauma to anatomical structures, malposition of the implant, and wound closure. Postsurgical factors include surgical asepsis, wound care, patient medications and self-care, future implant assessment by the dental team, and most importantly the mucoperiosteal-implant seal that is needed for long-term prognosis.⁴¹

Treatment and maintenance are more complex with dental implants. The tissues around dental implants react to bacteria similarly to the tissues around natural teeth. Pathogenic bacteria attach to dental implant surfaces leading to the potential breakdown of this biological seal surrounding the osseointegrated implant. Although the junctional epithelium attachment for dental implants is similar to natural dentition, the connective tissue interface with the dental implant has poor mechanical resistance. The lack of the connective tissue barrier around dental implants allows pathogenic bacteria access to destroy bone. This peri-implant disease process resembles periodontal disease with natural teeth. In fact, keratinized tissue is a vital outcome postoperatively, as plaque retention and pathogenic bacterial invasion will occur around titanium implant abutments. Frequent evaluation and assessment by the dental team is essential to the success of dental implant procedures.³¹ Many of the current self-care treatments for periodontal maintenance of natural teeth also can be used with dental implants, but a better understanding of these self-care practices by the patient is crucial for the health of the soft and hard tissues and the longevity of their dental implants.⁴⁹