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May 2009 | Dental Products Report How to: Replace a posterior mandibular tooth Using OCO Biomedical’s simplified implant system for a conservative, lasting replacement. It is common to see a patient present with an endodontically treated tooth that has sustained an unrestorable crown/tooth fracture below the gumline. According to Dr. Carl E. Misch’s Contemporary Implant Dentistry: Third Edition, “A mandibular first molar is often the first tooth lost in a permanent dentition. These teeth are the first to decay and the adult patient has had one or more crowns fabricated to restore the integrity of the tooth and replace previous large restorations. In most cases, the primary reason for failure of the crown is endodontic therapy, porcelain or tooth fracture, or uncemented restoration.” With time, these teeth usually need to be extracted and replaced. There are many options available for replacing a posterior single tooth, including a space maintainer, fixed partial denture, removable partial denture, resin bonded prosthesis, or implant prosthesis. In my opinion, the best option for replacing a single posterior tooth that is conservative, lasting and won’t jeopardize adjacent teeth is an implant-retained prosthesis. This case addresses the replacement of a posterior mandibular tooth using a simplified implant system. 01. A 49-year-old male patient presented for replacement of tooth No. 19 (Fig. 1). The tooth had been extracted two years previously because of a vertical fracture; the patient’s medical history was non-contributory. Different options available to replace the tooth were discussed with the patient as well as any risks, benefits and alternatives. He decided to have an implant placed in the area of tooth No. 19. 02. The area of tooth No. 19 was anesthetized using 1.8 mL of Septodont USA’s 4% Septocaine (septodontinc.com) with 1:100,000 epinephrine (Fig. 2). 03. Once anesthesia was administered, the implant site was begun with a #8 surgical bur in a highspeed handpiece, through the soft tissue about a millimeter through the bone. The location was centered facial-lingually as well as mesial-distally. Because the tooth being replaced was a molar and there was sufficient bone width and height, a 5 mm x 12 mm OCO Biomedical TSI dental implant was selected. 04. A 1.8 mm pilot drill was placed into the site and advanced to a depth of 14 mm measuring from the tissue surface. This additional 2 mm was the same depth of the tissue height to bone. In other words, 12 mm for the osteotomy in bone and 2 mm for tissue thickness was created to place a 12-mm-long implant. A parallel pin gauge was placed in the site of the osteotomy and an x-ray taken to check the angulations of the pin between the adjacent teeth within the mandible (Fig. 3). Using a rotary tissue punch—provided in the OCO Biomedical surgical kit—a 5 mm outline was created over the initial osteotomy and the tissue plug removed with a curette. Because there was a thin band of attached gingiva, a countersink drill was used to countersink the implant collar. 05. Once the osteotomy was completed, a 5 mm x 12 mm OCO Biomedical TSI threaded implant was placed in the osteotomy using an implant finger driver until increased torque was necessary. The ratchet wrench was then connected to the adapter and the implant torqued to final depth reaching a torque level of 65 Ncm (Fig. 4). 06. A 5 mm healing abutment, included with the implant, was hand-tightened to the implant (Fig. 5). 07. A post-operative radiograph was made of the implant and the healing abutment (Fig. 6). The implant was evaluated clinically after one week. 08. At three to four months the healing abutment was removed and the implant tested with reverse torque to ensure osteointegration. An impression was taken of the implant using OCO Biomedical’s I-Trip (Tissue Retraction Impression Pickup), which was then tried on to the TSI implant to check clearance for standard or triple tray, and alignment (Fig. 7). It was important to make sure the I-Trip displaced the gingiva and snapped over the collar of the implant. In fact, one can hear an audible “snap” when it is fully seated. 09. Because there was enough clearance and a tooth present on either side of the implant, a triple tray was used with a medium body polyvinyl siloxane impression material, Kerr Corp’s Take-One Advance (kerrdental.com). Once the impression material was set, it was removed from the mouth, picking up the I-Trip. 10. A 5.0 mm lab analog was snapped into the I-Trip within the impression and sent to the lab for pour up. From this pour up, a stock indexed 5 mm OCO Biomedical abutment was placed into the analog and consequently the PFM crown restoration fabricated (Figs. 8 and 9). 11. When the patient returned for the seating appointment, the abutment was placed into the implant (Fig. 10), torqued to 30 Ncm and an x-ray taken to verify it was completely seated. 12. A cotton plug was placed over the hex screw in the abutment, followed by Coltène/Whaledent’s TempoSil (coltenewhaledent.com) temporary cement. This procedure ensured the hex screw was protected should it be necessary to access the screw and retrieve the abutment later. 13. The PFM crown was placed on the abutment with its margins on the implant (Fig. 11) and another x-ray was taken to verify an accurate fit. Because there were no open margins and the contacts and occlusion were good, the crown restoration was seated using Kerr’s Maxcem Elite cement. Once the cement reached its gel stage, it was quickly cleaned off and any excess quickly and easily removed. The patient was very pleased with the end result and surprised at how atraumatically the dental implant was placed through the gingiva. In fact, a year later he had another dental implant placed in the position of tooth No. 29 when that tooth fractured. The final panorex depicts that the implant in area No.19 is still doing very well (Fig. 12).
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