While the prosthetic rehabilitation of

Restoring Mandibular Single Teeth with the Inclusive Tooth Replacement Solution Go online for in-depth content by Bradley C. Bockhorst, DMD While the prosthetic rehabilitation of full-arch cases provides a tremendous service for the patient and can be very professionally rewarding for the clinician, single tooth replacement is by far the most common implant restoration. Restoring single posterior teeth with implants provides a viable treatment option and has been well documented. 1-5 Of the single posterior teeth, the first molar, or money tooth as termed by Dr. Curtis Jansen, very often requires replacement. 6 At the Glidewell Laboratories operatory, 59 percent of the single Inclusive Tapered Implants placed have been in the posterior mandible. One of the most obvious concerns when placing implants in the posterior mandible is identifying and avoiding the inferior alveolar nerve (IAN). 7 This can be accomplished through the use of appropriate radiography and proper planning. Restoring Mandibular Single Teeth with the Inclusive Tooth Replacement Solution 19

Conventional implant planning typically involves the use of a periapical radiograph (PA) and/or a panoramic film. The drawback to these types of two-dimensional images is distortion. The PA should be taken with a paralleling technique to avoid vertical distortion as much as possible. A radiographic marker of known diameter (e.g., 5 mm ball bearing) can be used to determine the distortion in the planned implant site. The marker is measured on the film to determine the distortion factor in that area. A transparent overlay can be used as an aid to determine the correct implant selection (Fig. 1). Another option is a CT scan. Cone beam scanners provide a three-dimensional image and a precise method for identification of the IAN. 8 The patient s scan can be imported into planning software, the mandibular canal identified, and the implant placed in a virtual environment (Fig. 2). In the case presented here, the canal was well differentiated and identified. The mandibular canal is typically identifiable. However, there are situations where the cortical bone surrounding the canal is not dense and therefore does not show up radiographically. These cases present a significant challenge. One rule of thumb for first molars is to not drill deeper than the roots of the adjacent teeth. An optical scan of the model provides a clear view of the anatomy of the teeth and the soft tissue (Fig. 3). The appropriate-sized implant is placed within the confines of the available bone (Fig. 4). It is important to be aware that the drills are approximately 1 mm longer than the stated length of the implant. The trajectory of the implant is aimed toward the opposing stamp cusp through the center of the occlusal table. Figure 1: Implant radiographic template for Inclusive Tapered Implants Figure 2: Digital Treatment Plan Surgery The osteotomy should be prepared with the aid of a surgical or prosthetic guide. The prosthetic component of the Inclusive Tooth Replacement Solution is a traditional surgical stent designed to convey the ideal position of the implant platform from the restorative perspective (Figs. 5, 6). By starting the osteotomy using this guide, the implant will be inserted in the appropriate location to take advantage of the custom temporary abutment and BioTemps provisional crown. The prosthetic guide is intended for prosthetic reference only, and does not take into consideration any anatomical landmarks or contraindications. This guide should be used in combination with the radiographic and clinical information to determine the best position for the implant. Figure 3: View of mandibular arch with proposed implant trajectory A surgical guide based on the virtual plan utilizing a CBCT scan of the patient provides the option of drill depth and angulation control. Based on the amount of guidance desired, a surgical guide can be produced that guides the pilot drill. Subsequent drilling with progressively wider 20 www.inclusivemagazine.com

Figure 4: Cross-sectional view of proposed implant site Figure 7: Universal SurgiGuide Figure 5: The Inclusive Tooth Replacement Solution prosthetic guide Figure 8: Universal SurgiGuide in situ surgical drills (as needed) and implant placement are performed freehand. If additional guidance is needed, Universal SurgiGuides (Materialise Dental; Glen Burnie, Md.) are available (Figs. 7, 8). In these cases, all the drills can be guided. The implant is placed freehand once the osteotomy has been created. At the time of placement, a custom healing abutment can be delivered (Figs. 9, 10). The custom healing abutment allows you to start anatomically sculpting the soft tissues at the time of surgery. Figure 6: Prosthetic guide in situ A custom temporary abutment and BioTemps crown also are provided with the Inclusive Tooth Replacement Solution. If high primary stability is achieved and the crown is taken well out of occlusion, the implant can be temporized at the time of surgery. Due to the occlusal forces that can be exerted in the molar region, another approach would be to utilize the custom healing abutment at the time of surgery and provisionalize the case at a later date. Restoring Mandibular Single Teeth with the Inclusive Tooth Replacement Solution 21

Temporization Temporization utilizing the Inclusive Tooth Replacement Solution consists of seating the custom temporary abut ment, then relining and cementing the BioTemps provisional crown (Fig. 11). If a screw-retained temporary is preferred, after adjustments are made, an occlusal hole is drilled through the crown (Fig. 12). The abutment and internal surfaces are roughened up to help create mechanical retention. A guide pin is used to maintain the screw opening, and the crown is luted to the abutment with permanent cement. The crownabutment assembly is then delivered to the implant (Fig. 13), and the abutment screw is tightened to 15 Ncm (Fig. 14). The occlusal screw is covered with a piece of Teflon tape and the access opening sealed with composite (Fig. 15). The crown should be out of occlusion (Fig. 16). Figure 9: Inclusive Tooth Replacement Solution custom healing abutment Final Impressions The final impression is made with the Inclusive Tooth Replacement Solution custom impression coping (Fig. 17). The custom impression coping allows you to transfer the position of the implant as well as the soft tissue contours to the master cast. The custom impression coping is seated on the implant and the screw is tightened (Fig. 18). The access opening is sealed with soft wax to prevent impression material from flowing into the coping (Fig. 19). The closed-tray impression is made following standard technique. When the material has set, the impression is pulled. The impression coping is removed and replaced with the healing abutment or provisional restoration. The shade is selected (Fig. 20) and clinical photos are taken. A bite registration and impression of the opposing arch are made. The pre-populated Inclusive Tooth Replacement Solution lab prescription is filled out and the case sent to the lab. Figure 10: Custom healing abutment in place with access opening sealed Laboratory Fabrication Upon receipt, the lab will mount the custom impression coping on an implant analog (Fig. 21) and reseat it back into the impression (Fig. 22). A soft tissue model will be poured (Fig. 23), the case articulated, and the final restoration fabricated. Figure 11: Custom temporary abutment and BioTemps crown Based on the clinician s preference, a cemented or screwretained prosthesis can be ordered. In this case, the cemented restoration consisted of an Inclusive All-Zirconia Custom Abutment (Figs. 24a, 24b) and an IPS e.max crown (Ivoclar Vivadent; Amherst, N.Y.) (Fig. 25). An acrylic jig is fabricated to aid in seating the abutment (Figs. 26a, 26b). Final Delivery: Cement-Retained Crown When the healing abutment or provisional restoration is removed, the soft tissues will have healed to more Figure 12: After adjustments, a hole is drilled through the crown and the crown cemented to the abutment. 22 www.inclusivemagazine.com

Figure 13: Seated provisional restoration Figure 17: Custom impression coping Figure 14: The abutment screw is tightened Figure 18: The impression coping is seated Figure 15: The occlusal access opening is sealed Figure 19: The screw access opening is sealed with soft wax Figure 16: The temporary crown is out of occlusion Figure 20: Shade selection Restoring Mandibular Single Teeth with the Inclusive Tooth Replacement Solution 23

anatomically correct contours (Fig. 27). The abutment is seated utilizing the jig (Fig. 28) and the screw tightened to 35 Ncm (Fig. 29). The jig is then removed (Fig. 30). The crown is seated and the margins and interproximal and occlusal contacts are checked (Figs. 31a, 31b). Any necessary adjustments are made. There should be light centric contact with a firm bite and no lateral contacts. The interproximal contacts should be light. The abutment screw is tightened once more to 35 Ncm, and the access opening sealed with a piece of Teflon tape. The crown is cemented in place with RelyX Unicem Self-Adhesive Resin Cement (3M ESPE; St. Paul, Minn.). All excess cement must be meticulously removed. A PA was taken to verify complete seating and cement removal (Fig. 32). Final Delivery: IPS e.max Screw-Retained Crown If a screw-retained crown was selected (Figs. 33a 33c), the one-piece restoration is seated on the implant (Fig. 34). The abutment screw is tightened to 35 Ncm utilizing the jig (Fig. 35). The interproximal and occlusal contacts are checked and adjusted as needed (Fig. 36). The screw access opening is sealed with a piece of Teflon tape and an occlusal composite (Fig. 37). Figure 22: Assembly reseated into impression Summary Replacement of missing mandibular molars with singletooth implant-borne restorations provides many benefits over fixed partial dentures. It avoids having to prep adjacent teeth, it makes hygiene easier for the patient, and it allows for flexure of the mandible. 2 The osteotomy can be created conventionally or through a guided surgical procedure. The Inclusive Tooth Replacement Solution provides the components to simplify the restorative process and provide a superior final restoration for this common restoration. IM Figure 23: Soft tissue model Figures 24a, 24b: Inclusive All-Zirconia Custom Abutment Figure 21: Custom impression coping mounted on implant analog Figure 25: Inclusive All-Zirconia Custom Abutment and IPS e.max crown 24 www.inclusivemagazine.com

Figures 26a, 26b: Acrylic abutment seating jig Figure 30: The jig is removed Figure 27: The provisional restoration is removed Figures 31a, 31b: After adjustments, the IPS e.max crown is cemented in place Figure 28: The abutment is seated with the jig Figure 32: PA verifying seating and cement removal Figure 29: The abutment screw is tightened to 35 Ncm Figures 33a 33c: IPS e.max screw-retained crown Restoring Mandibular Single Teeth with the Inclusive Tooth Replacement Solution 25

References 1. Becker W, Becker BE. Replacement of maxillary and mandibular molars with single endosseous implant restorations: a retrospective study. J Prosthet Dent. 1995 Jul; 74(1):51 55. 2. Misch CE, Misch-Dietsh F, Silc J, Barboza E, Cianciola LJ, Kazor C. Posterior implant single-tooth replacement and status of adjacent teeth during a 10-year period: a retrospective report. J Periodontol. 2008 Dec;79(12):2378-82. 3. Misch CE. Endosteal implants for posterior single tooth replacement: alternatives, indications, contraindications, and limitations. J Oral Implantol. 1999;25(2):80-94. 4. Ekfeldt A, Carlsson GE, Börjesson G. Clinical evaluation of single tooth restorations supported by osseointegrated implants: a retrospective study. Int J Oral Maxillofac Implants. 1994 Mar-Apr;9(2):179 83. 5. Muftu A, Chapman RJ. Replacing posterior teeth with freestanding implants: fouryear prosthodontic results of a prospective study. J Am Dent Assoc. 1998 Aug; 129(8):1097 102. 6. Jansen C. Presentation given at the Academy of Osseointegration 2012 Annual Meeting, Phoenix, Ariz. 7. Anderson LC, Kosinski TF, Mentag PJ. A review of the intraosseous course of the nerves of the mandible. J Oral Implantol. 1991;17(4):394-403. 8. Alhassani AA, AlGhamdi AS. Inferior alveolar nerve injury in implant dentistry: diagnosis, causes, prevention, and management. J Oral Implantol. 2010;36(5):401-7. Epub 2010 Jun 14. Figure 34: Abutment screw tightened utilizing jig Figure 35: IPS e.max screw-retained crown seated Figure 36: Occlusion verified Figure 37: Access opening sealed with composite 26 www.inclusivemagazine.com