Choosing an Implant System for Clinical Practice: An Evidence-Based Method
More than 50 companies manufacture “root-form” dental implants based on the principle of osseointegration. Many of these companies manufacture more than one implant design. This situation presents clinicians with a somewhat daunting task when deciding which implant system will be best for their patients.The experienced clinician likely will have developed confidence in the perfo rmance of the implant system or systems used in his or her practice. Hovever, manufacturers will continually present new claims of improved performance, ease-of-use, and cost effectiveness.Those clinicians just beginning to employ implant dentistry in their practice lack the clinical experience on which to base their decisions, and therefore face a greater challenge. Both experienced and inexperienced clinicians should develop a strategy to select the most appropriate implant system for their patients. A reasonable starting point for this strategy is confirmation that the appropriate government authority has licensed the implant system under consideration. A second point of reference is verification that the appropriate national dental association has approved the implant system. Third, and most important, the clinician should determine if the system can be validated by publications in peer-reviewed literature. This chapter reviews the application of this validation strategy in the United States and Canada.
In the United States, the Food and Drug Administration (FDA) is responsible for monitoring the safety and effectiveness of medical devices. The distribution of dental implants is controlled by this agency. The FDA’s objective is not to be a testing facility, but instead is to determine that data and results supplied by private sources follow FDA program guidelines. At one point, dental implants were placed in the Class III medical devices category, which required premarket approval. Premarket approval is a demanding process that includes controlled preclinical and clinical studies documenting an implant system’s efficacy before it is allowed to enter the commercial market. No dental implant manufacturer has completed the premarket approval process. Manufacturers have been able to market their products by demonstrating “substantial equivalence” to previously approved devices. This form of approval is known as 5 10(k) or premarket notification. Devices do not have to be identical to previously marketed implants to be classified as substantially equivalent.The manufacturer is required to demonstrate only the same intended use (such as for edentulous, partially edentulous, or single-tooth applications) and the same technological characteristics. Manufacturers must provide a detailed narrative of the design characteristics, including diagrams, material specifications, and tolerances; sterilization info rmation and labeling details; and results of static and fatigue testing in compression and shear. If the implant has the same intended use, but with different technological characteristics, then safety and effectiveness must be demonstrated. Corrosion tests and toxicology tests are required only when a new material is used that has not been identified in a previously marketed device.Animal and/or clinical studies are required only for implants with a diameter of less than 3 mm and lengths shorter than 7 mm and for abutments with angulations greater than 30 degrees.1,2 Clinical data is not needed for most devices cleared by 5 10(k).3
The American Dental Association (ADA) has, as part of its Seal of Acceptance program, an acceptance program for endosseous implants. This is a voluntary program for which a manufacturer must supply evidence of physical properties (eg, modulus of elasticity, strength, and hardness); tests establishing biocompatibility; and clinical studies including two independent prospective clinical studies with a minimum succes/>