A Retrospective Survival Study of Trabecular Tantalum Implants Immediately Placed in Posterior Extraction Sockets Using a Flapless Technique
A retrospective review of patient records was conducted in a single private practice to evaluate the efficacy of immediately placing a novel implant design in posterior jaw locations using a flapless technique. Forty-two patients (22 males, 20 females) with a mean (SD) age of 60.2 (7.6) years (range = 31–68) presented with 1–2 nonrestorable molar (maxillary = 14; mandibular = 8) or premolar (maxillary = 20; mandibular = 1) teeth compromised by periodontal disease, endodontic failure, root resorption, root fracture, or severe caries. Most patients (78.6%) had moderate (66.7%) or severe (11.9%) periodontitis. Other comorbidities included smoking (14.3%) and controlled diabetes mellitus (11.9%). After atraumatic extraction, teeth were immediately replaced with a total of 44 trabecular tantalum implants (Trabecular Metal Implants, Zimmer Biomet Dental) (diameter = 3.7–4.7 mm; length = 10–13 mm). Sites requiring augmentation were treated with 3 types of small-particle (250–1000 μm), mineralized, solvent-dehydrated, allografts (Puros) based on location: cortical for crestal sinus grafts, cancellous for peri-implant voids in thick tissue biotypes, or cortical-cancellous (70:30) mix for peri-implant voids in thin tissue biotypes. Cortical particulate was used when slower resorption would help maintain graft volume for esthetics or implant support. Grafts were covered with resorbable bovine pericardium membranes (CopiOs, Zimmer Biomet). Cumulative implant survival and success rates were 97.7%, respectively, with a mean (±SD) follow-up time of 25.0 ± 12.1 months (range = 4–48). One asymptomatic implant failed to osseointegrate. Within the limitations of this study, implants achieved outcomes comparable to conventionally placed and restored single-tooth implants in anterior jaw locations.
Figure 1. Case No. 1: After atraumatic flapless extraction of the nonrestorable maxillary right first premolar (#5), an implant was placed according to the manufacturer's protocol. The lingual aspect of the extraction socket was engaged during osteotomy preparation, which extended 3 to 4 mm past the apex of the extracted tooth to form a “primary stability rectangle.” Note that the distance between the walls of the implant and the adjacent osseous crest allows for the minimum 0.5 mm of space to prevent resorption of the interproximal bone during remodeling and healing. The peri-implant voids are filled with small-particle MSDBA. Figure 2. Case No. 1: Postoperative periapical radiograph shows the implant, graft and provisional prosthesis in place. Figure 3. Case No. 1: Occlusal view of screw-retained acrylic provisional prosthesis fabricated chairside. Note the screw access hole in the center of the occlusal surface and the reduced marginal ridges. Figure 4. Case No. 1: Buccal view shows that the cusp have been reduced to eliminate contacts in centric protrusive and excursive movements.
Figure 5. Case No. 1: Occlusal view shows the soft tissue contour of the healed extraction site after removal of the provisional prosthesis. Figure 6. Case No. 1: Buccal view of the healed extraction site shows the preserved papilla. Figure 7. Case No. 1: Periapical radiograph after delivery of the definitive screw-retained prosthesis. Note that the interproximal bone levels remained stable throughout healing and osseointegration of the implant. Figure 8. Case No. 1: Clinical buccal view of the definitive screw-retained, porcelain-fused-to-high-noble metal, implant-supported crown in place.
Figure 9. Case No. 2: Occlusal view of a nonrestorable maxillary left first molar (#14). Figure 10. Case No. 2: Buccal view of the nonrestorable tooth. Figure 11. Case No. 2: Sagittal view on the cone beam computerized tomography (CBCT) image sliced through the center of tooth #14. Note the furcal bone width and height appears adequate for immediate implant placement. The maxillary sinus area is also free of any notable pathology if crestal sinus elevation is needed. Axial view of the CBCT image sliced through the center of tooth #14. Note the height of the furcal dome and the adequate bone apical to the root tips. The distance from the top of the furcal dome to the floor of the maxillary sinus is adequate for achievement of primary stability, but vertical sinus augmentation via the crestal approach will needed.
Figure 12. Case No. 2: Atruamatic extraction of tooth #14 following careful sectioning and elevation preserved the thick buccal plate and wide furcal dome. Figure 13. Case No. 2: The osteotomy is prepared in the center of the furcal dome and the vertical augmentation via the crestal osteotome technique is performed using small particle cortical MSDBA. Figure 14. Case No. 2: After implant placement in the prepared osteotomy, remaining peri-implant voids are filled with small-particle MSDBA. After engaging a cover screw, a pericardium membrane is placed over the site and primary closure is attempted with 5.0 vicryl sutures. Figure 15. Case No. 2: An immediate postoperative periapical radiograph of the maxillary left first molar #14. Figure 16. Case No. 2: Clinical image shows a buccal view of the definitive, screw-retained, porcelain-fused-to-high-noble-metal, implant-supported crown #14. Figure 17. Case No. 2: Periapical radiograph after delivery of the definitive screw-retained prosthesis.
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