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A New Protocol for Immediate Functional Loading of Dental Implants By Thomas J. Balshi, DDS, FACP Case Report The patient was a 70-year-old male who presented with advanced periodontal disease that had caused a total loss of bone support around the mandibular anterior teeth (Fig 1,2,3). Mobility of the remaining teeth in the mandibular arch and a pronounced tongue thrust was causing them to lean labially (Fig 4,5). To replace his missing maxillary anterior teeth, the patient was wearing a maxillary removable partial denture. Multiple molars were missing as well, and malocclusion was severe. A comprehensive radiographic analysis, including intraoral periapical films, a panradiograph (Fig 6), and a lateral cephalometric film confirmed that the patient suffered from advanced periodontal disease with associated large periapical lesions throughout the mandibular anterior. Apical to these lesions, however, an ample amount of healthy bone remained. The remaining mandibular molar was restoratively hopeless. Because of financial limitations, the patient requested that initial treatment be confined to the mandibular arch. He was advised that following the extraction of his remaining mandibular teeth and placement of the implants, he might be a candidate for the Teeth in a DayTM protocol. He indicated that he preferred this option to that of wearing a traditional removable complete denture during the healing phase. However, he was informed that final evaluation of the quality of his alveolar bone would have to await the implant-placement surgery. While every effort would be made to provide him with permanent teeth at that time, the presence of Type IV bone might necessitate use of the temporary removable denture. On this basis, he elected to proceed with the recommended TEETH IN A DAYTM protocol and treatment. We then thoroughly reviewed the informed consent for treatment. Alginate impressions and interocclusal registrations were made to allow the technical staff to fabricate the immediate mandibular complete denture. Complete oral hygiene and surface debridement is routinely performed in most patients prior to TEETH IN A DAYTM surgery. In addition, the patient thoroughly rinses with a chlorhexidine mouthwash immediately before the surgery commences. The authors have found that general anesthesia is advisable in about 50 percent of the patients provided with Teeth in a DayTM, typically when dental phobias are severe or surgical procedures promise to be lengthy and complex. However, as neither condition existed in this case, local anesthesia was achieved using a total of six carpules of Bupivacaine hydrochloride (Marcaine 0.5%: Cook-Waite, Abbott Laboratories, North Chicago IL) for bilateral blocks of the inferior alveolar nerve and buccal and labial vestibular infiltrations. All remaining anterior mandibular teeth were removed. The extraction sockets were thoroughly debrided of all soft tissue and irrigated with a tetracycline solution (Fig 8,9). An alveoloplasty was done to remove any excess and sharp bony projections. Preparation of the implant receptor sites then commenced. In the course of drilling, the surgeon determined that the bone quality was Type III bone according to Lekholm and Zarb's classification scheme24. Since this is normally sufficient to allow for use of the Teeth in a DayTM protocol, the mandibular removable immediate denture that had been prepared in advance was sent to the on-site laboratory for initiation of the conversion-prosthesis protocol developed by the authors in 198625. This involves reinforcing the prosthesis labially with a wire while relieving it lingually to allow for its placement in centric relation without contacting the prosthetic screws or cylinders (Fig 10). While this was being accomplished by the laboratory technicians, the prosthodontist placed six 3.75mm-diameter, 20mm-long Brånemark implants (Nobel Biocare USA, Yorba Linda, CA) in the anterior mandible (Fig 11). Minimal bone tapping was used to ensure maximal stability of the implants. Four standard and two EsthetiCone Brånemark abutments were connected to the implants and tightened to the recommended torque of 20 Ncm (Fig 12). Customized prosthetic cylinders (fabricated from stainless steel, screw-retained Brånemark impression copings) were placed onto the abutments and secured with customized-length guide pins that permitted the mandible to be closed in centric relation without the components interfering with the occlusion. In order to protect the site during the next phase of the operation, transfer ink was applied to the top of the prosthetic cylinders, and a rubber dam (Hygenic by Coltene/Whaledent Inc., Mahwah, New Jersey) was placed over these and gently patted. This recorded the implant locations on the rubber. A rubber punch was then utilized to create tiny holes at these positions, and the rubber dam was slipped over the prosthetic components and moved downward to the junction of the prosthetic cylinders and the titanium abutments (Fig 13,14). The rubber dam protects the soft tissue and exposed bone from the heat generated by the extreme reaction of the autopolymerizing acrylic resin as it sets. It also provides a dry field for the conversion process and prevents the acrylic from locking into undercuts between the abutments. The barrel of a 50 ml syringe was loaded with Jet Acrylic (Lang Dental Manufacturing Co., Wheeling, Illinois). After injecting the resin to thoroughly coat all the prosthetic components (Fig 15), a small amount of resin was also inserted into the newly hollowed denture. The denture was then placed in the patient's mouth in the proper interocclusal position in centric relation position (Fig 16). The occlusal/vertical dimension was confirmed. The patient was instructed to hold still for approximately four minutes while the acrylic polymerized. (The rubber dam also provides a thermal barrier during this process, protecting the soft tissue from the heat generated by the exothermic reaction of the resin as it sets.) Once the resin had hardened, the patient was instructed to open his mouth again. The prosthesis was then unscrewed and taken from the operatory to the laboratory for structural enhancement, refinement, and polishing. While this was taking place, the soft tissue was approximated, obtaining a secure adaptation around the titanium abutments using vicryl sutures. Postoperative panoramic and cephalometric radiographs were taken to evaluate the position of the implants (Fig 17,18). The completed prosthesis was attached to the abutments with gold screws, and the occlusal relationship was assessed one more time (Fig 19,20). The patient was extremely happy with the esthetic result of treatment (Fig 21,22). He was instructed to eat only soft foods and avoid placing pressure on the prosthesis for three months. After that period, he returned and a secondary impression was recorded, using the Teeth in a DayTM prosthesis as an impression stent. A week later, the patient returned for one final visit, during which the temporary prosthesis was unscrewed and replaced with the permanent prosthesis. No anesthesia was required on either of the two follow-up visits. |
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