Tooth Preservation Vs. Implant Therapy: What’s Best for the Patient?
Q: What are effective treatment-planning concepts with regards to triaging a tooth for either root canal therapy or a dental implant?
In a recent systematic review of long-term tooth and implant survival rates (published in JADA, October 2013), Drs. Liran Levin and Michal Halperin-Sternfeld, two periodontists from Harvard School of Dental Medicine in Boston and Rambam Health Care Campus in Haifa, Israel, described the following practical implications of their literature review: “The results of this systematic review show that implant survival rates do not exceed those of compromised but adequately treated and maintained teeth, supporting the notion that the decision to extract a tooth and place a dental implant should be made cautiously. Even when a tooth seems to be compromised and requires treatment to be maintained, implant treatment also might require additional surgical procedures that might pose some risks as well. Furthermore, a tooth can be extracted and replaced at any time; however, extraction is a definitive and irreversible treatment.”1
The authors included published outcome studies with a minimum 15-year follow-up and arrived at a conclusion that many experienced clinicians observe on a daily basis in their clinical practice—that seemingly questionable teeth often last much longer than expected.
While implant dentistry has been a great addition to the dental treatment-planning repertoire of choices, the decision to extract and replace a tooth with an implant should be considered only if the odds of tooth retention are significantly lower than successful implant placement. A discussion of the entire gamut of treatment-planning concepts for deciding whether to save or extract any given tooth would require much more than a few short paragraphs; however, such concepts revolve around understanding the risks involved with each treatment modality and comparing them with the alternative option.
In the final analysis, since these factors are case-specific, consultation with experienced specialists in both fields of endodontics and implant dentistry is recommended for an even-handed understanding of the treatment-planning options for any given case. Therefore, for the most accurate decision regarding the merits of saving or extracting a questionable tooth, my recommendation is to include both the surgeon and endodontist in the treatment-planning phase of the tooth in question.
The question of whether to save a tooth or recommend extraction is well worth the discussion. In fact, it could be argued that many more teeth are unnecessarily extracted due to misdiagnosis than are unnecessarily saved. Although this decision is often a straightforward one, clinicians can find it a struggle on what to recommend for their patients. Therefore, it is important to understand what the deciding factors are and to de-construct all the parameters in order to make optimal recommendations for patients. It is also important to remember that predictability of treatments is directly related to the proper diagnostic and treatment approaches.
What used to be considered herodontics—a term used to describe ongoing treatment of severely structurally compromised teeth—is now part of everyday routine endodontics, which has seen advances in techniques and materials such as bioceramics. More conservative instrumentation techniques are allowing for increased life expectancy of teeth due to the preservation of radicular dentin. While practitioners in the past might have relied on high volumes of gutta percha in the canal, dentistry today has come to realize that often “less is more,” which can translate to fewer vertical root fractures.
The recommendation to extract a tooth should be meticulously thought out. For example, not all cases of resorption equal extraction; not all isolated deep periodontal probings are fractures—as any endodontist will attest. As clinicians know, it is not the radiograph that is being treated; rather, it is the teeth. Treatment, of course, should not be based on hunches but on the factors involved such as available restorable tooth structure, adequate ferrule to support a restoration, and the health of the supporting periodontium. Other considerations include the patient’s natural bite and any parafunctional habits that will influence long-term outcomes.
Before making a decision to extract the cornerstones of the dentition—the first molar or canine—especially on a young patient—it is important to consider such factors as crown-to-root ratio, root thickness and length, and, finally, even the occasional crown-lengthening procedure if indicated. Cosmetics and esthetics are also key considerations when determining treatment options.
The most successful practice approach is a patient-centered one. Recommendations should be made that make sense—for the patient.
As a periodontist, when I am faced with the treatment-planning options of referring a patient for root canal treatment or recommending extraction and subsequent implant therapy there are several factors that I take into consideration:
1. Patient’s medical history and ASA classification. Is the patient a candidate for multiple surgeries, including extraction and socket graft and implant surgery? Patients with certain health concerns, such as the following, may face fewer medical complications with root canal therapy: use of oral bisphosphonates; poorly controlled diabetes; high level of dental anxiety coupled with hypertension when unable to undergo conscious sedation.
2. Does the tooth in question need extensive crown lengthening requiring bone removal to capture a margin and provide adequate retention? If the future crown-to-root ratio will drop below 1:1 or the adjacent tooth will be compromised from the removal of bone, it may be more conservative to extract the tooth and graft the socket in preparation for a dental implant.
3. Location of the tooth in the arch.
• Bone regeneration of the premaxilla in a vertical dimension is still not a predictable science. A root canal and crown may still provide the best esthetic outcome.
• Anatomical considerations must be made, especially with regard to a lower second molar where the location of the inferior alveolar nerve and lingual concavity might preclude implant surgery.
4. The predicted success rate of conventional therapy to save the tooth. If I feel that the root canal treated and properly restored tooth will be successful for 5 years or more, I recommend saving the tooth. Dentistry is a rapidly evolving field with tremendous scientific improvements in technology and materials. It is exciting to think about the options that might be available to the patient should the tooth fail in 5 years or beyond.
ABOUT THE AUTHORS
Allen Ali Nasseh, DDS, MMSc
President, RealWorldEndo™, Wilmington, Delaware; Clinical Instructor, Department of Restorative Dentistry and Biomaterial Sciences, Harvard University School of Dental Medicine, Boston, Massachusetts; Private Practice, Boston, Massachusetts
Nader Vafaie, DMD, MMSc
Private Practice, Novato, California
Sharona Dayan, DDS, DMSc
Private Practice, Weston, Massachusetts; Diplomate, American Board of Periodontology
1. Levin L, Halperin-Sternfeld M. Tooth preservation or implant placement: A systematic review of long-term tooth and implant survival rates. J Am Dent Assoc. 2013;144(10):1119-1133.