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march 2015 — Vol. 10, No. 3 www.dental-tribune.com IMPLANT TRIBUNE The World’s Dental Implant Newspaper · U.S. Edition Primary stability vs. viable constraint: A need to redefine AAID: Digital implant dentistry isn’t the future By AAID Staff D igital implant dentistry is not the future. No, far from it. Digital implant dentistry is the here and now for dental implant practioners. From digital treatment planning and delivery to patient communica- tion, new technologies are changing the way dentists practice implant dentistry. The American Academy of Implant Dentistry presents a course titled “Implant Dentistry in the Digi- tal World” in Baltimore from April 24-25. In addition to offering 12 hours of C.E., the AAID is honoring Dr. Leon- ard Linkow, one of the pioneers of the field of dental implants, with a dinner on Friday, April 24. The conference, which is co-hosted by the AAID’s Northeast and South- ern Districts, will be held at the Mar- riott Inner Harbor at Camden Yards in Baltimore. More information and registration is available online at www.aaid.com. The following programs are among those to be included: • “CBCT Implant Planning: Digital Solutions from a Laboratory Perspec- tive” (Joe “Ambrose” D’Ambrosia, CDT) • “Reverse Engineering in Digital Smile Design” (Alain Méthot, DMD) • “Innovations in Digital Implantol- ogy” (Gilbert Tremblay, DMD, FAAID, DABOI/ID) • “Technology to Enhance Your Practice” (Marty Jablow, DMD) • “Fixed Implant Prosthetic Consid- erations” (Shankar Iyer, DDS, MDS, FAAID, DABOI/ID) • “Planning the Rehabilitation of an Edentulous Arch” (Lou Dipede, DMD) • “Soft-Tissue Management in Im- plant Therapy” (John F. Hamrick, DMD, FAAID, DABOI/ID) • “Protocols to Avoid Complications and Failures with the New Digital Workflow” (Scott Ganz, DMD) Established in 1951, the AAID is the only dental implant organization that offers credentials recognized by fed- eral and state courts as bona fide. Its membership, which exceeds 5,000, includes general dentists, oral sur- geons, periodontists and prosthodon- tists from across the United States and in 40 other countries. For more information, contact AAID at aaid@ aaid.com or at (312) 335-1550 or (877) 335-AAID (2243). Fig. 1 Fig. 2 By Michael R. Norton, BDS, FDS, RCS(Ed) A ny regular reader of the Journal of Oral & Maxillofacial Implants or in- deed of any other publication on dental implants could not fail to have noticed how much attention has been focused on primary stability. The concept of primary stability is not new; indeed, as early as the 1970s, there were studies emphasizing the need to estab- lish mechanical stability to ensure un- interrupted healing of the bone.1 This was most evident in the orthopedic lit- erature as it pertains to hip prostheses.2 By the 1990s, numerous reports were being published on immediate loading of dental implants,3-6 and the ground- breaking work by Neil Meredith on the application of resonance frequency analysis (RFA) came to the fore7-9 with statements that achievement of implant stability was a prerequisite for long- term positive outcomes. At the same time, Meredith recog- nized it was possible for clinically firm implants with poor axial stability to still be prone to failure.8 Of course, Brånemark recognized this in his early work, proposing as he did a period of submerged healing because of his con- cerns for any destabilization of the bone-to-implant interface during the early healing phase. However, today, we all recognize that such protective protocols are frequently unnecessary, with widespread acceptance of not only transmucosal healing but also immedi- ate temporization and/or loading. So how do we define primary stability? The most simple definition is one of me- chanical friction between the implant and bone. Certainly, we can all appreciate that this contrasts with secondary implant stability where secondary stability is achieved by biological integration, i.e., osseointegration. The gradual shift from primary sta- bility to secondary stability is critically poised at around three weeks. This is seen to be the least stable time point where viscoelastic stress relaxation of the bone along with remodeling results in a loss of primary mechanical stabil- ity9 but with an as yet poorly established degree of secondary stability or osseoin- tegration. This is also apparent in RFA curves, which, like a heartbeat, always register a certain pattern in healthy bone that reflects this loss of stability at the third or fourth week,10 regardless of bone den- sity. That said, we still need to define what constitutes primary stability, i.e., that which sets it apart from biological in- tegration. As stated above, mechanical stability is one where a friction occurs between the implant and the surround- ing bone, giving rise to a resisting torque at time of insertion. This resisting torque is proportional to the effort required to seat the implant or peak insertion torque; they are in essence one and the same and depend largely on the characteristics of the im- plant, the density of the bone and the differential size of the osteotomy as it pertains to the diameter of the implant. “ STABILITY, Page D2