Evaluating the clinical performance of the Osseotite implant: defining prosthetic predictability.

A 5-year prospective, multicenter study is in progress at four private dental practices to determine the cumulative implant survival rate and prosthetic outcome when using the Osseotite dental implant in posterior maxillary and mandibular areas. An interim evaluation after 34.4 months of study progress is presented. A total of 219 Osseotite implants were placed in 74 patients (34 women and 40 men with a mean age of 57.8 +/- 15.2 years) using a conventional two-stage surgical protocol and 3- to 6-month healing time. Subsequently, patients were restored with fixed or removable restorations. Nineteen of the 74 patients reported smoking an average of 13.2 cigarettes per day. Restorative treatments included 40 single-unit restorations; 53 splinted 2-, 3-, 4-, and 5-unit implant-supported maxillary and mandibular prostheses; 4 full-arch fixed maxillary prostheses; 1 mandibular fixed/detachable hybrid prosthesis; and 1 mandibular overdenture. The mean time from implant placement to second stage surgery was 6.2 +/- 2.0 months; from restoration and implant loading to the most recent follow-up evaluation was 20.9 +/- 6.8 months. Of the 219 implants placed, three posterior maxillary implants developed infections and were removed prior to second stage surgery. No implant failures occurred at second stage surgery or after implant loading. Using the Kaplan-Meier method, the cumulative implant survival rate was 100% for anterior implants and 98.4% for posterior implants at 28.5 +/- 5.7 months. The cumulative postloading implant survival rate was 100% for both anterior and posterior implants. The results of this study indicate that the Osseotite dental implant achieved a high rate of integration that remained stable during nearly 2 years of implant function. In addition, because no postloading implant failures have occurred, the Osseotite implant has provided a high level of prosthetic predictability.

Implant-supported single tooth replacement in the aesthetic region: a complex challenge.

The placement of a single tooth implant-supported restoration in the maxillary anterior area still presents a difficult challenge. To address this challenge, various methods and techniques have been proposed. The learning objective of this article is to present a particular clinical protocol for achieving predictable aesthetic restoration, even under the relatively difficult circumstances involving thin, highly scalloped gingiva and high lip line. A clinical case is used to illustrate the presentation of implant surgery, bone regeneration, connective tissue graft, provisionalization, and placement of the definitive prosthetic restorations. The use of pressure to expand soft tissue is described, and the importance of papillae protection is emphasized.

The microbiota of osseointegrated implants in patients with a history of periodontal disease.

The purpose of this study was to determine the presence of suspected periodontal pathogens in the peri-implant microflora of osseointegrated implants exposed 3 and 6 months to the oral environment of patients previously treated for periodontal disease. Subgingival microbial samples were taken in the deepest residual pocket of each quadrant in 10 patients before placement of ITI implants and in 10 patients before abutment connection of Brånemark implants. The samples were cultured using continuous anaerobic techniques. 4 patients were positive for P. gingivalis, 13 for P. intermedia, 2 for A. actinomycetemcomitans, 16 for Fusobacterium, 7 for C. rectus and 12 showed microscopic evidence of spirochetes. After 3 and 6 months exposure of the implants to the oral environment, one sample was obtained from the peri-implant sulcus in each patient. P. gingivalis was found in 2 patients in the peri-implant samples after 3 and 6 months. 6 peri-implant samples were positive for P. intermedia after 3 months, 7 after 6 months. Fusobacterium was present in 13 peri-implant samples after 3, and in 12 samples after 6 months. 4 patients showed evidence of for C. rectus after 3 months, 2 after 6 months. Spirochetes were seen in 3 peri-implant samples after 3 and in 5 after 6 months. None of the implants were found to be colonized by A. actinomycetemcomitans, although the organism was detected on teeth in 1 individual. Similar distribution patterns were noted for ITI and Brånemark type implants.(ABSTRACT TRUNCATED AT 250 WORDS)

Periodontal repair or regeneration: structures of different types of new attachment.

The present study details the structural and ultrastructural features of healing events between the regenerated periodontal ligament and the root surface after experimental periodontal disease. Experiments were performed on dogs, and the concept of guided tissue regeneration was tested using resorbable polyurethane membranes. Light microscopy, scanning- and transmission electron microscopy were employed to determine if healing events involve regeneration (ie, process by which the architecture and the function are completely renewed) or periodontal repair (ie, healing of a wound by tissue that does not fully restore the architecture of a part). Regeneration occurred in parts of the roots only if some original cementum remained on the root surface after root planing. Repair was observed if peripheral dentin was removed by root planing as this layer was not reestablished. In areas remote from the base of the defect, new collagen fibrils, synthesized by fibroblasts and oriented perpendicular to the root surface, were spliced with severed ends of Sharpey's fiber bundles of original cementum. If circumpulpal dentin was exposed, intermingling between new fibrils with dentinal matrix fibrils occurred. In areas near the base of the defect, the first event was the formation of a cementoid by a cementoblast monolayer and subsequent formation of intrinsic fibrils oriented parallel to the root surface. Afterwards, the cementoblast monolayer disintegrated and extrinsic fiber bundles became anchored in the new cellular mixed fiber cementum. In these areas, linkage between new cementum and pre-existing tissues always occurred by interfacial intermingling of the fibrils, regardless of whether new attachment occurred at circumpulpal dentin or original cementum.

Comparison of tricalcium phosphate and frozen allogenic bone implants in man.

As part of their treatment, eight patients with 47 infrabony pockets and horizontal bone defects had 29 tricalcium phosphate and 18 frozen allogenic bone implants placed. One year after surgery the sites were reentered. At the tricalcium phosphate implant sites the average amount of bone apposition was 1.2 mm and pocket depth induction 1.8 mm; 38% of the pockets remained deeper than 3.0 mm. At the allogenic bone sites the average amount of bone apposition was 1.5 mm and pocket depth reduction was 2.0 mm; 22% of the pockets remained deeper than 3.0 mm. The implant materials were well tolerated and there were no complications during the period of the study. Though storage and handling of tricalcium phosphate was simpler, use of allogenic bone led to greater bone apposition and reduction in pocket depth.

The angiographic tension test in mucogingival surgery.

Attached gingiva's integrity was studied with the aid of fluorescein angiography and a standardized frenal tension test in 15 subjects aged between 19 and 41 years (9 female, 6 male) with mucogingival pathology in the region of the mandibular labial frenum. Each subject showed preoperatively gingival angiographic ischemia under 200 p frenal traction. The angiographic ischemia was in no case congruent to the clinical ischemia. One month after surgical enlargement of attached gingiva (eight grafts of palatal mucosa, seven subperiosteal vestibulum extension) both mucogingival surgery techniques successfully prevented the gingival blood circulation from showing ischemia clinically as well as angiographically under 200 p frenal traction.

[Tricalcium phosphate and its biodegradable ceramics in periodontal bone surgery. A review of the literature]. / Trikalziumphosphat und dessen biologisch abbaubare Keramik in der parodontalen Knochenchirurgie Eine Literaturübersicht.

The chemistry, structure, biocompatibility and effect of biodegradable tricalcium phosphate and tricalcium phosphate ceramic are evaluated with the pertinent literature. With proper indication and use the biodegradable tricalcium phosphate implants for the formation of new bone and reattachment in periodontal pockets may be successful. The biodegradable material has to be sufficiently tried out and examined in further animal and clinical studies before recommending it for general use.

[Are allogeneic spongiosa grafts ready for general practice?]. / Sind allogene Spongiosaimplantate praxisreif?

9 subjects with 23 infrabony pockets were filled with 2 differently stored allogenic implants. After 6 months the average pocket reduction was 2.7 mm and bone apposition was 1.0 mm. Surgical corrections were often necessary because of postsurgical flap shrinkage. The relatively demanding procedure makes allogenic bone implants with questionable success not yet an acceptable operative technique for the nonspecialist.