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12 mCME Dental Tribune Middle East & Africa Edition | 6/2017 One patient, one doctor: 30 years of implant innovation mCME articles in Dental Tribune have been approved by: HAAD as having educational content for 1 CME Credit Hour DHA awarded this program for 1 CPD Credit Point CAPP designates this activity for 1 CE Credit By Jack A. Hahn, DDS Since placing my fi rst dental im- plant 45 years ago, many implant systems have come and gone, sev- eral of which I designed myself. If there’s one thing I’ve learned from the thousands of implant cases I’ve completed during the course of my career, it’s that regardless of the im- plant system chosen, long-term suc- cess depends on following the basic principles of treatment planning, surgery and prosthetic design. Innovations in implant design have streamlined and simplifi ed treat- ment, making it easier to produce ideal outcomes. Key advancements, such as the screw-shaped implant body, the internal prosthetic con- nection and the tapered body design, have been crucial in making implan- tology the essential mode of tooth replacement it is today. The following case illustrates more than three decades of implant evo- Fig.2 Fig.3 Fig.4 Fig.5 Fig. Fig.1: Dr. Jack A. Hahn and Glidewell Laboratories President and CEO Jim Glidewell display the Hahn Tapered Implant — the culmina- tion of decades of clinical observations and innovation. (Photos/Provided by Dr. Jack A. Hahn) lution within the mouth of a single patient. Each implant this patient received throughout the years rep- resents a small but signifi cant step forward, culminating in the place- ment of the Hahn™ Tapered Im- plant (Glidewell Direct; Irvine, Calif.), which I designed in order to make treatment simpler, more predictable and as accessible to as many patients as possible. The patient The patient, whom I’ve been treating for more than 30 years, has received implant therapy several times to treat tooth loss from fracture or de- cay. Because this treatment occurred episodically throughout many years, I’ve utilized several different implant systems to replace the patient’s teeth. As a result, the patient has im- plants with internal as well as exter- nal hex connections, ranging from an outdated bladeform design to the very latest tapered implant. The experience I’ve had both designing and placing these implants for this patient and thousands of others has given me the unique opportunity to observe my results and determine what designs and protocols work and what can be improved, as I’ve strived to advance implant design through- out the years. The implants • JAH 2000 Blade Implant (Fig. 3): I fi rst placed an implant for this pa- tient in 1988. It was the JAH 2000, which I designed as a fl at, two-piece implant with wings. The blade im- plant was indicated for thin ridges where a root-form implant could not be placed without bone grafting. Blade implants were typically con- nected to other implants or teeth, and could be cut, shortened and shaped to align with the anatomy of the bone, which was commonly required when placing blade-form implants at the time. For this patient, two teeth anterior to the implant were prepared, an incision was made, a trough was drilled in the patient’s very narrow ridge, the implant was placed and a fi ve-unit bridge was delivered to replace three teeth in the posterior mandible. Notice that I adjusted the distal inferior portion of the implant so as not to impinge on the mandibular nerve. The JAH 2000 was a signifi cant im- provement over what was on the market at that time. I designed the neck to extend lower than the tops of the wings, allowing more bone to integrate around the neck of the im- plant. Decades after implant place- ment, this blade design continues to serve many of my patients well. • Steri-Oss HL (Fig. 4): The Steri-Oss HL implant in the area of tooth #26 is HA-coated and was placed imme- diately into an extraction site of a tooth that was lost to severe caries. Beginning in 1986, my practice was one of multiple centers conducting a 12-year study on nearly 3,000 Steri- Oss implants.1 We gained provisional ADA approval for extraction with immediate implant placement and loading. The Steri-Oss HL had a machined col- lar, which facilitates excellent hard- and soft-tissue preservation. As the clinicians in the 12-year study noted at the two-year follow-up, there was little to no bone loss radiographically around the machined collar. That’s why I decided to include a machined collar in my later designs. • Replace® Select Tapered (Fig. 5): I placed several Replace Select im- plants (Nobel Biocare; Yorba Linda, Calif.) for this patient throughout the years, and the tapered shape simpli- fi ed positioning within the available bone, especially in the area of the pre- maxilla. Prior to the Replace Select, most implants were parallel-walled, and in 1993 I came up with the con- cept of a tapered design, although it didn’t come to market until 1997. The idea arose from my experience with single-tooth replacements in the anterior maxilla, where I’d often need to tilt parallel-walled implants to the facial to avoid perforating the subnasal fossa. The roots of natural teeth are tapered, so it occurred to me that implants should be tapered as well. The bone is not square; it’s a series of triangles that is best accom- modated by a tapered shape. A fl at top with an internal connec- tion offered an esthetic advantage because the implant could be placed at or slightly below the crest of the bone, without an external compo- nent causing metal to show through the crown. This led to the design of the tri-lobe internal connection of the Replace Select, which was fi rst introduced by Steri-Oss and became the most popular design in the No- bel Biocare implant portfolio after the company acquired the brand in 1998. The thread pattern of the Replace Se- lect was similar to that of the parallel- walled Steri-Oss implant, but I want- ed to have a variant of aggressiveness in the pitch of the threads as it came up to the apex. I knew that another company was coming out with four different implants for the different qualities of bone, and I wanted to beat them to the punch. So I said, “Let’s put four different thread pat- terns in one implant,” which really helped with the degree of taper and cutting into denser bone. The tapered shape of the Replace Select was ideal for two-stage treat- ment, but the thread design wasn’t aggressive enough to provide the stability I needed for single-stage sur- gery. This left me wanting a thread design that was more sharp-edged — but not too aggressive — which was one of the formative ideas behind the Hahn Tapered Implant. • Hahn Tapered Implant (Fig. 6): Like several of the implants I’ve placed for this patient, the two Hahn Tapered Implants shown in the panoramic radiograph (Fig. 2) were placed im- mediately following extractions. The patient is active socially and has al- ways wanted an immediate tempo- rary after having a tooth extracted. In both cases, I extracted the tooth, prepared the site and placed the im- plant. ÿPage 13