Paradigm Shifts

by Mark Nicolucci, DDS, MS, FRCD(C)

Dental implants are a standard of care in dentistry but this wasn’t always true. I distinctly remember one of my dental instructors saying I shouldn’t get involved in that “voodoo” dentistry. Perhaps he had heard the ADA say in the late ’70s that dental implants were not recommended for routine clinical practice and was simply passing along the message. This dogma persisted for much of the 20th century but eventually implants gained acceptance and acclaim. This was in part due to major advancements in implantology: improvements in implant designs and surfaces, surgical protocols, grafting techniques and more. While many of these changes were welcomed and heralded, others have remarkably been resisted.

It has been said truth goes through three stages: first it is ridiculed, then it is violently opposed and finally it is accepted as self-evident. This sequence describes the difficulty with paradigm shifts, especially when something else is already believed to be true. In working with many colleagues I see a whole range of understandings about implant dentistry and most agree on certain things; for example, implants should be surrounded by bone and osseointegration takes time. Other concepts are sometimes challenged but generally well accepted, such as immediate placement or loading of implants, or guided implant surgery. But a few concepts remain opposed by a significant number of people. I hope to bring attention to two salient concepts. Part of the reason they stand out is that research supports treatment that does not align with traditional dogma.

The first is that the implant surface is sacred. The original thought was that the implant surface should not be altered as it could create defects which would compromise the “surface integrity”. This was perhaps understandable with older smooth machined implants but modern implant surfaces are designed with significant roughness. On initial placement these surface irregularities help encourage contact osteogenesis, however, after placement they can be used to harbour bacteria and plaque. To prevent accumulation, surface alteration should be a goal of regular maintenance on exposed rough implant surfaces. In other words, scaling can help smooth an exposed implant surface making it less plaque retentive. For hygienists who may be fearful of this concept I would ask what they prefer: a rough surface with calculus or a smooth surface without. This question often hammers the point home.

The second concept is that oral forces cause implant failure or crestal bone loss. On the contrary, our evidence suggests oral forces on implants have no effect on either. Animal studies where healthy osseointegrated implants were put in severe hyperocclusion failed to demonstrate any crestal bone or implant loss and humans studies with accentuated forces (cantilevers, angled implants, large prostheses on few implants) consistently report no impact on crestal bone and no difference in implant survival. These observations are often challenged by anecdotes where an implant fails and occlusion or forces are an easy scapegoat. Oral forces do produce numerous mechanical complications (screw loosening, material fracture) but in well controlled studies the “biomechanical” impact is absent. This understanding allows us to recommend advanced prosthetic designs that were previously thought contraindicated. In this very journal, Dr. Pollack showcases the use of an angled implant to better treat his patient. I hope this commentary may further encourage others to follow suit.

These concepts are only some of a list of advances that are shifting the way we practise. As implantology progresses, so too does all of dentistry. These changes are important to consider when providing care to our patients. When evaluating them, it is best to keep an open mind and always look to the evidence.

About the Author

Dr. Mark Nicolucci is Oral Health’s editorial board member for implantology. He is a graduate of the University of Western Ontario and received his specialty certificate from Temple University in periodontology and oral implantology. He has a masters in oral biology and lectures regularly in the Toronto area. He maintains a full-time specialty practice in West Toronto.

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