Nov 2009 —
Choosing an Implant System: an Evidence-based Approach as a Viable Option?
Neel Bhatavadekar, BDS, MS, MPH
With the large dental implant market, the dentist can now theoretically choose from more than 2000 implants for any particular treatment.1 Thus, strong scientific evidence is needed to help clinicians in their decision making. In the hierarchy of scientific literature, preclinical (in vitro and in vivo) studies and case reports form the lower end of the evidence spectrum with randomized controlled trials (RCTs) and meta-analyses at the upper end.2 Case reports are ranked lower in the hierarchy of evidence because they lack control groups and are nonrandomized.
In vitro and in vivo models are probably best suited for analyzing implant surface characteristics. However, an RCT published in a peer-reviewed journal is often considered the ultimate measure of an implant’s clinical efficacy.3 An evidence-based decision involves differentiating between this hierarchy of evidence and making the most optimal treatment decision based on high-quality peer-reviewed published literature while trying to eliminate any risk of bias from potential confounding factors.
However, from a practical standpoint, do clinicians really choose an implant based on solid published evidence or merely clinical experience? In light of the emerging trend for evidence-based clinical decision making, this article examines the relevance of published evidence and its practical applications when choosing an implant system for a particular surgical site. It also seeks to provide information regarding factors, such as regulatory mechanisms, that might influence the availability of extensive published literature and thus impact the clinician’s ability to make an evidence-based implant selection.
Implant marketing claims and supporting evidence
Several implant companies publish clinical claims to promote their products to clinicians. In a previous report,3 the author assessed if these claims could be substantiated with the published evidence available. Using specific inclusion criteria, the author had conducted a qualitative and quantitative analysis of peer-reviewed literature available from implant companies and focused on the availability of RCTs and meta-analysis reports. These form the highest quality in an evidential hierarchy.2 The Cochrane Collaboration also conducted qualitative analysis of these RCTs using risk of bias as a surrogate variable4 and found great heterogeneity in data. Not all the claims proposed by these companies could be substantiated on the basis of well-controlled RCTs. Several clinical claims might be based on in vitro data and studies that do not report long-term follow-up. For instance, an implant company might claim that its implant leads to better esthetic results when all the published reports are either in vitro or on an animal model, without the existence of long-term human clinical trials. Also, it would be important to distinguish whether the publications are from a corporate or a peer-reviewed journal because the latter is typically less biased. It thus behooves the clinician to remember these factors when choosing an implant system based merely on its marketing claims.
Availability of clinical evidence for implant systems
The regulatory mechanisms for dental implants might have a role in the lack of strong evidence for some implant systems. A unified European certification board (CE certification) and the US Food and Drug Administration regulate the accreditation of endosseous dental implants. In the United States, submission of a 510(k) premarket notification, consisting of documentation that the new implant has substantial equivalence to a product that is already on the market, is one way to obtain implant accreditation. Thus, implants with 510(k) clearance would not technically need as much supporting preclinical and clinical evidence compared with a new device that does not fit these criteria.3 In India, the Central Drugs Standard Control Organization oversees the approval of drugs and medical devices as well as the regulation of clinical trials.5 By implementing a more thorough regulation of dental implant imports, the Medical Devices Regulation Bill introduced in 2006 might change the way dental implants are marketed in India.6 It remains to be seen if the revised criteria for importing or manufacturing a dental implant in India will include the requirement of long-term human trials before subsequent marketing claims can be made.
How would these factors impact a clinician from a practical standpoint? If the current clinical decisions are being made solely on the basis of the published marketing claims, a closer assessment of these claims might change the choice of an implant for a specific surgical situation. Also, a change in the regulatory requirements in the Indian market might impact the availability of dental implants with less than the prerequisite published evidence. Not every clinical claim can be tested with a long-term human RCT. However, any claim proposed by an implant company should be supported with good evidence, within reason. The availability of several Web portals such as PubMed7 and the Cochrane Collaboration review articles8 have greatly simplified access to high-quality published evidence and consensus reports on clinical questions. Thus, an evidence-based approach to implant decisions is an easily achievable and viable option even for the busy clinician.
Evidence-based decision making is a viable and accessible option that can greatly assist clinicians in determining optimal treatment choices for their patients. The clinician should assess the strength of evidence behind each implant system and not rely merely on company marketing claims. Web-portal and Web-based treatment decision algorithms can provide a plethora of information about existing studies and guide to the clinician in making evidence-based decisions built on the hierarchy of published literature.
This article does not represent the policies or opinions of any of the institutions with which author is affiliated.
1. Jokstad A, Braegger U, Brunski JB, et al. Quality of dental implants. Int Dent J. 2003;53(6 suppl 2):409-443.
2. Levels of evidence. Centre for Evidence Based Medicine Web site. http://www.cebm.net/?o=1025. Accessed May 6, 2009.
3. Bhatavadekar NB. Assessing the evidence supporting the claims of select dental implant surfaces: a systematic review. Int Dent J. 2008;58(6): 363-370.
4. Cochrane Reviewer Handbook for Systematic Reviews of Interventions. Cochrane Collaboration Web site. http://www.cochrane-handbook.org. Updated 2006. Accessed May 6, 2009.
5. Central Drugs Standard Control Organization Web site. http: //cdsco.nic.in. Accessed July 30, 2009.
6. Department of Science and Technology, Government of India Web site. http://www.dst.gov.in. Accessed July 30, 2009.
7. PubMed. US National Library of Medicine Web site. http://www.ncbi.nlm.nih.gov/pubmed. Accessed July 7, 2009.
8. The Cochrane Collaboration Web site. http://www.cochrane.org. Accessed July 30, 2009.
|About the Author
|Neel Bhatavadekar is an Assistant Professor at the University of Texas Health Science Center, and an Adjunct at the Department of Bioengineering, Rice University, Houston, Texas.