Introduction

Implantology is the most controversial discipline in dentistry today. Its advocates claim that it can alter the course of restorative dentistry; its detractors criticize it as impractical and emphasize its failures. I am, of course, an advocate, but I must stress that I promote only a limited number of procedures suitable for specific situations. These procedures are based upon careful observations of tissue morphology and upon biomechanical principles applicable to both natural and artificial dentition. These procedures have also proven clinically successful in a significant number of situations.

Although dental implantology is not a new field, only recently has it provoked widespread interest. The major reason for this is the success of certain implant procedures. An added factor is the recognition that technological advances, particularly in the development of light-weight materials tolerable to the human body, have resolved basic medical problems.

If there are successful implant designs and techniques, why does the controversy persist? Largely because implantologists have been isolated from the mainstream of dentistry, the profession has been unable to differentiate between practical implant designs and absurd ones. Due to its promise, implantology has attracted a flood of new experimentation that has obscured years of carefully refined concepts and techniques. The profession and the public are simultaneously presented with "advances" that will truly benefit the patient and contribute to the art of prosthodontics, together with "advances" already explored and rejected in the Dark Ages of Implantology that passed—largely unnoticed by the majority of the profession—many years ago. In implantology, as well as in any other subject, those who are ignorant of its history are condemned to repeat it—and its mistakes.

Another significant factor in the implant controversy is the large number of failures. Poorly conceived implant designs cannot succeed, and they account for a significant proportion of the statistics. The most carefully designed implant will also fail if inserted incorrectly. Unpredictable circumstances, such as prolonged delays in laboratory procedures or faulty prosthodontics, also adversely affect implant prognosis. We must admit that in the early stages of an implant intervention the balance between success and failure tends to be precarious, even with good designs. A failure in implant insertion is usually detectable

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