Root Canal vs. Implant
At a recent local implant seminar, the clinician speaker, a representative of a leading implant manufacturer, reportedly told the audience that endodontic retreatment had a success rate of 46% in comparison to implant success rates at 98% (an accurate estimate of retreatment success is 80-85%). This speaker was terribly misinformed or choosing to misrepresent endodontic retreatment in an effort to promote implant placement on behalf of the implant manufacturer.
A recent blog post discussed a recent surge of misinformation regarding endodontic retreatment among the general population as well as the dental community. Anyone close to the dental industry is familiar with the massive marketing efforts of the implant manufacturers. Typically, these marketing efforts are in the form of clinician representatives speaking on behalf of the implant manufacturer in a continuing education presentation.
That is not the only point that is misrepresented by implant marketers. There are some important points that are routinely overlooked when comparing endodontic and implant research. You will not hear these points at your next implant seminar.
Teeth and Implants are not the same which makes direct comparison difficult
In a systematic review of outcomes of single implants and endodontically treated teeth, Iqbal and Kim (2007) restricted their outcome measurement to survival. After reviewing 13 studies involving RCT, 55 studies with implants, and 1 study directly comparing the two, their meta-analysis found 94% survival of RCT and 96% survival of single implants at 5 years. Their study revealed no significant difference between the root canals and single implants.
After reviewing the root canal and implant outcomes, Zitzmann et. al. (2009) noted, “Due to similar outcomes of implant treatment and RCT, the decision to treat a tooth endodontically or replace it with an implant, must be based on factors other than anticipated treatment outcome alone.”
Comparing endodontic “success” with implant “survival” is like comparing apples and oranges. There are also a number of differences between endodontic and implant studies which may make proposed implant “success” rates artificially high. The following are a few examples
These are two VERY different ways of determining statistical success. If you remove any early failure, your statistics at the end of the study are skewed and misleading.
Patients who think that removing a tooth and replacing it with an implant will resolve all their dental problems are misinformed.
Patient pools are different.
Bain et. al. reported the comparative incidence of implant failure in smokers vs. non-smokers at 11.28% to 4.28% and De Bruyn et. al. reported the same at 31% to 4%.
These are two VERY different groups of patients. Exclusion of non-ideal patients in a study likely creates a higher “success” rate than would be seen in an average population.
These are two VERY different types of occlusal function. Once again, because teeth and implants are not the same, we ask and expect very different type of function from each group.
Specialist vs. Generalist
In any study, it is important to look at the clinicians performing the study. Are the procedures performed by dental students, residents, general practitioners or specialists? Historically, many endodontic studies have been performed by dental students. It is well known that general dentists perform a majority of the root canals every year. Hull et. al. (2003) reported that according to the dental claims in Washington in 1999, 64.7% of the root canals were performed by general dentists. Alley et. al.(2004), in a survey of survivability regarding root canals done by general dentists and specialists, reported that the specialist had significantly greater success (98.1%) than the general dentists (89.7%). In contrast, most dental implants have historically been placed by specialists. With the growing trend of implant placement by general dentists, the success rates previously reported cannot be assumed accurate in the clinical setting by general dentists.
Not all research is equal.
We all want to make sure that our treatment recommendations are in line with current scientific evidence. However, not all scientific studies provide the same level of evidence. A systematic review or randomized, controlled, double blind study has a much higher level of evidence than a case report, expert opinion, or epidemiologic study. In a systematic review of the endodontic literature, Torabinjad et. al. (2005) examined endodontic articles related to the success of endodontic treatment and found only 6 of 306 articles that were considered in the highest level (level 1 of 5) of evidence (randomized, clinical trials). 26 were considered level 2 (low-quality randomized control trials, cohort studies), 5 were level 3 (case-controlled studies, systematic review of case-controlled studies), 82 were level 4 (low-quality cohort studies, case-control studies, case series), and 178 were level 5 (case reports, epidemiological studies, expert opinion, literature reviews). This does not reflect well for evidence based treatment recommendations based upon this body of evidence. However, Torabinejad et. al. (2007), in another systematic review of outcome studies involving root canals and single implants found that the quality of endodontic studies higher than that of the implant studies, which were case series analysis 64% of the time. Erkert et. al. (2005) reported that the six major ADA-certified dental implant manufacturers, when asked for research validating their implant system, submitted evidence generally derived from level 4 case series studies, rather than controlled clinical trials or cohort studies.
As professionals, we are responsible for understanding and interpreting the scientific research in order to provide our patients with evidence based treatment recommendations. With much of the current continuing education provided/sponsored by the dental industry, we are tasked with the responsibility of deciphering what is marketing hype from what is valid, scientific, data.
In our practice, we routinely recommend implant therapy for patients who have missing teeth or teeth that are non-restorable. If you are unsure regarding the restorability of a tooth, team up with your endodontist. He/She should have the technology, including microscopes and CBCT and experience to help make this important decision.