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Implant Tribune Asia Pacific Edition

22 TRENDS & APPLICATIONS Implant Tribune Asia Pacifi c Edition | 4/2017 The use gf narrgw implants 1 5 2 6 3 7 4 8 Fig. 1: Initial situation with the strongly resorbed tooth #53 in situ.—Fig. 2: Dental panoramic tomogram showing the initial situation.—Fig. 3: The preparation was performed precisely using a Nentwig osteotome.— Fig. 4: The autologous bone was ground and harvested using the K-system.—Fig. 5: The preparation was performed to the correct depth using a 2.6 drill.—Fig. 6: Insertion of the implant 1 mm below the bone crest level.—Fig. 7: Radiograph after implantation.—Fig. 8: The PEEK abutment in situ. By Dr Huub van’t Veld, Netherlands The development of very narrow implants can provide a solution for interdental spaces in the aesthetic zone that are smaller than 5–6 mm and in which implant placement is indicated to fi ll the diastema with an implant-supported crown. In- creasingly, in the choice of implant, not only the quantity (> 1 mm) and quality of the surrounding bone are important, but the supporting function of the bone to obtain a good mucosal seal is too. The major implant brands have developed small-diameter implants for these narrow spaces. Nobel Biocare has the 3 mm NobelActive implant, concerning which many publica- tions have already appeared. Dent- sply Sirona has the OsseoSpeed 3 mm implant (part of the Astra Tech Implant System) and the Xive 3.0 implant. In 1976 already, the US Food and Drug Administration defi ned implants with a diameter of 3 mm and greater as conventional dental implants. In 1997, this agency de- fi ned implants with a diameter smaller than 3 mm as small-diam- eter implants. This mainly con- cerns one-piece implants used in very narrow jaws for a removable device or as an anchor for ortho- dontic appliances. These implants often consist of one piece owing to the fragility of the connection be- tween the implant and abutment in such a narrow diameter. Unfor- tunately, they offer too few options for a crown because it is not possi- ble to choose abutments with dif- ferent angles for a perfect pros- thetic solution. Therefore, the prac- titioner has to choose an implant with a separate abutment. Most narrow implants have a conical connection between the implant and abutment. This connection is attached via a screw. Stress tests have shown that the screw is the most limiting factor with stress. A solid abutment and a conical con- nection with a Morse taper of suffi - cient length and a cone of between 1.5 and 4° result in a nearly leak- proof and rigid connection be- tween abutment and implant. This is referred to as a “cold weld”. This makes such an implant almost as strong as a one-piece implant. In this article, I discuss the treatment procedure of two pa- tients I treated with 2.8 mm Axiom implants (Anthogyr) and present the fi nal results. Case 1 The fi rst patient was referred to me by her dentist owing to a persis- tent tooth #53 (Fig. 1), which occa- sionally caused pain and had begun to exhibit mobility. Tooth #13 was congenitally absent, as was tooth #23, which I had already re- placed with an implant with a crown in 2011 (Fig. 2). At the time, the left side of the upper jaw still had suffi cient space for a 3.4 mm implant (Ankylos, Dentsply Sirona). In the top right at tooth #53, I only measured an interdental space of 4.8 mm. I decided to use a 12.0 × 2.8 mm implant with a 4.0 mm and 1.5° Morse taper. I chose this implant on the one hand because the manufacturer prom- ised that considerable primary sta- bility could be achieved owing to the aggressive threading in the lower third of the implant and on the other hand because the resid- ual root of tooth #53 was very short. The latter allowed a small ex- traction alveolus and thus suffi - cient bone for good primary stabil- ity and consequently the possibil- ity of seating a temporary crown immediately after implantation. I removed tooth #53 atraumati- cally; the mesial and distal papillae remained intact. By using a very sharp osteotome (Nentwig) as a guide, I determined the location (more palatal) and direction of the preparation (Fig. 3). I gently tapped the osteotome to approximately 8 mm (according to calibration) into the jaw bone, and by rotating it slightly, I achieved a good guide preparation. After this, I used the K-system (DentaK) for further preparation (Fig. 4). This set consists of a hollow drill shaft containing a grinder in which, during further preparation, the bone is collected and then used to fi ll the space around the preparation and the re- sidual alveolar bone. I drilled to no more than two-thirds of the desired preparation length. The narrowest K-drill has a 3.2 mm diameter so that the preparation at the top is slightly wider than the 2.8 mm im- plant to be used. This allows one to adjust the implant somewhat in the axial direction if necessary. I used a 2.6 drill of the Anthogyr implant system (Fig. 5) to prepare to the cor- rect length. The total length of the preparation was 13 mm, allowing placement of the implant 1 mm below the bone crest (Fig. 6). In this manner, very good primary stabil- ity is achieved (> 35 Ncm; Fig. 9). After fi tting a temporary abut- ment made of PEEK (Fig. 8), I fabri- cated a temporary composite crown. A PEEK temporary abut- ment is easy to construct using composite or temporary resin. This 9 10 11a 11b 12a 12b 12c 13 Fig. 9: The harvested bone was placed around the implant with the K-system. —Fig. 10: The temporary crown in situ. —Figs. 11a & b: (a) Transfer of the abutment with a transfer key. (b) Structure impaction using the Safe Lock instrument. —Figs. 12a – c: (a) Result six months after starting treatment. (b) Result 20 months after starting treatment. (c) Radiograph 20 months after starting treatment. —Fig. 13: Clinical image of the initial situation with bonded bridge in situ.

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