Jessica J. Zachar
Context
Whether a questionable tooth should be treated endodontically or extracted, is still a dilemma that clinicians encounter every day. With advances in technology such as implantology, deciding whether or not to save a tooth is still not clear.
Local site-specific factors and patient-related factors that may affect the longevity of a particular tooth should be considered in preparing the treatment plan. Long-term success rates for root canal therapy and implant-supported crowns demonstrate similar outcomes.
A choice between these alone is not sufficient in the decision-making process. Only following a systematic evaluation of the reasons for and against tooth retention as directed by each individual case, can the best option be decided.
There is endless literature available on this topic, with no current clinical standard evaluation method to use when deciding the most appropriate option for a particular tooth.
Key Findings
- Diabetes in patients can negatively impact the healing of peri-apical lesions in endodontically treated teeth (3–7).
- Smoking, immunosuppression, insufficient oral hygiene, a history of aggressive periodontitis and uncontrolled diabetes can have an elevated risk in complications for the placement of implants (8–14).
- Patients who have received treatment of intravenous bisphosphonate for more than two years and have a history of complicated wound healing, such as in tooth extraction, may not be a candidate for implant treatment due to the risk of bisphosphonate-induced osteonecrosis (15).
- In young adults (25 years and below) who require single tooth replacement especially in the maxillary anterior region, implant placement should be delayed.
- In periodontics, the prognosis for a tooth is classified on the following clinical findings: the amount of attachment loss, its residual probing pocket and furcation involvement (3, 4). The longevity of periodontally involved questionable teeth over a 15-year study showed that 43–60% of teeth were lost during periodontal therapy and maintenance (20). Therefore the decision to retain or extract should be based on the level of disease.
- A questionable tooth after root canal treatment has no clinical symptoms, but has a periapical radiolucency present that can take months to years for complete healing (22). The presence of a peri-apical radiolucency causes a direct impact on the success rate.
- Questionable tooth that did not have a crown placed afterwards were at a six times greater risk of being extracted (24).
- When restoring endodontically treated teeth, optimizing the biomechanical behaviour of the tooth includes preserving intact coronal and radicular tooth structure and maintaining cervical tissue to create a ferrule effect. A literature review performed in 2012 emphasized that 0.0015–0.002 m ferrule has a positive effect on fracture resistance for endodontically treated teeth (26).
- The presence of adjacent teeth and the entire remaining dentition should be included in the treatment planning. If a questionable tooth is in an intact arch that can be kept as a free-standing unit then more options can be implemented for retention.
- A patient’s past positive and negative experiences will determine their attitude and have a strong influence on which procedure they choose (17).
- The evidence presented clearly indicates that the extraction of a natural tooth without any consideration of its health will result in a failure to recognize risks and complications that may possibly arise with implant treatment.
- Restoring a single tooth with a questionable prognosis, but with risks may be acceptable in particular cases. However, if the tooth has multiple risk factors, more complex procedures such as an abutment for a long-span FDP, should not be considered.
- Multiple risk factors tend to indicate tooth extraction and possible replacement by an implant, particularly in the posterior region when aesthetics are not crucial.
References
Retention of a tooth is important – but in the greater context of proper functional occlusion. We have to step back from our dental “tunnel vision” of focusing on margins and line angles, to consider the occlusion as a whole. Sadly, if you mention Occlusal Disease to a group of dentists, there is a significant cohort that will stare at you with a blank look on their faces. Even the American Dental Association is starting to recognize and use this term. Occlusal disease is probably the most important and the least considered cause of dental failure, be it in the natural dentition or in the restored dentition. It’s a travesty to see multiple implants placed in a person with a poor occlusion, only to have them develop TMD issues or have their restorations fail because the dentist focused on the teeth first, and not on ensuring there was a stable occlusal starting point. I’ve seen this too many times. The fundamental problem is that teaching occlusion in dental faculties is generally weak at the best of times, and to REALLY understand it you have to take involved and expensive CE courses. But for those of you out there considering this, it’s absolutely worth it to you and your patients.