We can all agree that one of the most exciting and important innovations in dental care is the discipline of implant dentistry. It is truly satisfying to find that over the past 50 years, implant dentistry has gone from being the treatment of doubt to the desired state-of-the-art treatment. The AAID and its membership have played key roles in this transition. Most days dentists and hygienists are treating patients who have dental implants. Approximately 3 million people in the U.S. have dental implants, and more than 500,000 implants are placed each year with a predicted $13 billion market by 2023.(1, 2)
Systematic reviews evaluating survival rates of implants found that 2-3% of placed implants are lost during the healing phase and the annual failure rate following loading is 0.3% to 1.3%. This represents an impressive 10-yr survival rate of implant-supported single crowns of 95.2% (3), implant-supported fixed dental prostheses of 93.1% (4), and combination tooth-implant supported prostheses of 82.1% (5).
Löe, et al. performed a 26-year study examining and predicting the survival of natural teeth. Tooth evaluations were based upon the Löe & Silness gingival index (GI).(6) The investigators based their findings on the following group criteria:
Severity Group 1: Teeth presenting throughout the 26-year time that always had a GI value of 1. These teeth always presented with healthy gingival tissue that never bled on probing during the study. Teeth in this group had a 10-year survival rate of 100%.
Severity Group 2: Teeth presenting with a GI value of 2. These teeth had healthy gingival tissue at some examinations and at others, demonstrated gingival inflammation (bleeding on probing). This group also had a 10-year survival rate of 100%.
Severity Group 3: Teeth presenting with a GI value of 3. These teeth demonstrated bleeding on probing at all sites during all examinations throughout the study, indicating continual gingival inflammation. Surprisingly, these teeth had a 10-year survival rate of 99%.
However, when the authors calculated the 50-year survival rate they found that teeth presenting as:
Severity Group 1 had a 99.5% survival,
Severity Group 2 had a 93.8% survival, and
Severity Group 3 only had a 63.4% survival rate.
Teeth with continual gingival inflammation had a 46-times higher risk of being lost. Löe, et al. concluded that healthy teeth without gingival inflammation demonstrate extremely high survival rates over decades, but teeth presenting with continual inflammation had a much lower survival rate over a patient's lifetime. (7) Once we have decades-long studies on implants it is reasonable to believe that continual inflammation may have the same detrimental effect on survival of dental implants.
When considering teeth with restorations Myamoto et al. found in a retrospective 15-to-23-year study that included 3071 teeth, that restored teeth had a lower survival rate than unrestored teeth. Teeth with large 3-5 surface restorations were 4 times more likely to fail when compared to unrestored teeth. (8) Raedel et al. in 2020 found that the cumulative six-year survival rates for teeth restored with metal and metal-ceramic crowns was 88% based on the outcome of “crown removal or tooth extraction”. (9) Drammaschke found that endodontically treated teeth with a apical lesion had a significantly shorter survival rate than endodontically treated teeth without apical lesions. The study found that overall, endodontically treated teeth had a 10-year survival rate of 85.1%.(10) Sadaf found that endodontically treated teeth with a core buildup restoration had a survival rate of 83% and 73% for those with a crown restoration.(11)
As Implant Dentists, we can have confidence in recommending and take pride in restoring patients with implant supported fixed or removable prosthesis. However, implant clinicians and patients must remember that implants and the restorations are at risk of biological and technical complications. Implants will never surpass the longevity of healthy, clean natural teeth that are free of caries and gingival inflammation. However, implant longevity does compare favorably to teeth that have continual proximal gingival inflammation or have required restoration. Implants are not without complications. Complications can lead to pain, anxiety, disappointment, and financial burdens. The goal of the implant clinician is to help the patient minimize complications beginning with proper treatment planning, surgical treatments, prosthetic restoration, and long-term maintenance. If complications can be prevented, then possibly healthy disease-free implants can be equal in longevity to healthy disease-free teeth.
The AAID's Annual Conference is taking place in Dallas, Texas on September 21-21, 2022. The meeting's theme is: “Zero In On Zero Complications”. Presentations will have a focus on prevention of implant complications by zeroing in on the challenges we all face. World renowned implant specialists will be presenting on all aspects of implant complications. Imagine how much better life will be for our patients and office by reducing implant failure rates by 5% or more. Learning from the list of esteemed speakers may be one of the best investments we can make.