Immediate and delayed implant placement into extraction sockets: a 5-year report.

BACKGROUND: As a complement to the earlier reported 3-year results from a prospective multicenter study of immediate and delayed placement of implants into fresh extraction sockets, the 5-year results are reported. PURPOSE: The purpose of this 5-year report was to evaluate the immediate and long-term success of implants placed into fresh extraction sockets, with respect to implant size and type, bone quality and quantity, implant position, initial socket depth, and reason for tooth extraction. MATERIALS AND METHODS: This paper presents the 5-year results of the original 12 centers that participated with 143 consecutively included patients. A total of 264 implants were placed either immediately after tooth extraction or after a short soft-tissue healing time (3-5 weeks). The patients were divided into five subgroups, depending on the type of insertion method used. RESULTS: The outcome demonstrated that the cumulative implant survival rate after 5 years of loading has not changed and remains 92.4% in the maxilla and 94.7% in the mandible. No difference in failure rates can be seen between the groups when relating the failures to insertion method. CONCLUSION: This prospective study demonstrated that placing Brånemark implants into fresh extraction sites can be successful over a period of 5 years of loading. One of the outcomes of the study shows that there is a clinical correlation between implant failure and periodontitis as a reason for tooth extraction, even if it is difficult to give it a casual association. It can be hypothesized that periodontitis affected tissues might have a negative local influence because of the presence of infrabony defects that could possibly increase the gap between bone and implant or jeopardize achievement of primary stability.

Treatment of ligature-induced peri-implantitis using guided tissue regeneration: a clinical and histologic study in the beagle dog.

This study evaluated the treatment of ligature-induced peri-implantitis using guided tissue regeneration (GTR) around submerged and nonsubmerged implants in beagle dogs. Two titanium implants were placed bilaterally in the premolar regions of the mandible in each of 10 beagle dogs. Cotton floss ligatures were placed around the implant necks and no oral hygiene procedures were performed for 5 months. Periodontal surgery was performed, and in five dogs (submerged group) the abutments were removed and an e-PTFE barrier was placed to cover the test implants and their adjacent osseous defects, while the control implants received no barriers. In the other five dogs (nonsubmerged group), flap surgery was performed without removing the abutments. In the test sites, an e-PTFE barrier was placed around the abutment and adjacent defects, while on the control sites no barrier was placed. Nondecalcified specimens were prepared using standard histologic methods and analyzed. No differences were found between any of the clinical parameters in both the control and experimental sites from the submerged and nonsubmerged groups. Histologic and histomorphometric analyses also revealed no significant differences between groups with regard to new bone formation. In the experimental (GTR) groups, however, the amount of regenerated connective tissue was significantly greater than on the control groups. Under the conditions of this study, the treatment of peri-implantitis using GTR did not enhance clinical parameters or bone formation around "diseased" implants.

A 3-year prospective multicenter follow-up report on the immediate and delayed-immediate placement of implants.

A total of 264 implants was placed in 143 patients using different immediate or delayed-immediate implant placement techniques in 12 different centers participating in a prospective multicenter study. The reason for tooth extraction was evaluated; bone quality and quantity were classified; socket depths were registered; and data on implant type, size, and position were collected. One hundred thirty-nine suprastructures were placed on 228 implants in 126 patients. A follow-up evaluation was done on 125 patients after 1 year of loading and on 107 patients after 3 years of loading. Clinical parameters (bleeding or not bleeding, pocket depth, and implant mobility) were evaluated after 1 and 3 years, and the marginal bone level after 1 year of loading was measured on radiographs. Clinical comparisons were performed to evaluate implant loss in relation to implant type, size, position, bone quality and quantity, socket depth, reason for tooth extraction, and placement method. In addition, life table analysis was done for cumulative implant survival rates. There was no clinical difference with respect to socket depth or when comparing the different placement methods. A higher failure rate was found for short implants in the posterior region of the maxilla and when periodontitis was cited as a reason for tooth extraction. Mean marginal bone resorption from the time of loading to the 1-year follow-up was 0.8 mm in the maxilla and 0.5 mm in the mandible. Over a period of 3 years, the implant survival rate was 92.4% in the maxilla and 94.7% in the mandible.

Immediate functional loading of immediate implants in edentulous arches: two-year results.

The purpose of this study was to evaluate the clinical success of immediate functional loading of immediate implants in edentulous arches. Five maxillary and five mandibular jaws were treated, and a total of 91 implants were placed; 66 of these implants were placed immediately after tooth extraction, and 25 were placed in healed sites. No bone substitutes or barrier membranes were used. Within 24 hours, fixed temporary restorations were inserted in all cases. During the entire 6-month healing time, all fixed temporary restorations were in normal function, after which the final fixed implant-supported restorations were inserted. After 24 months, the overall success rate of the implants was 92.31% (87.50% for the maxillary implants and 97.26% for the mandibular implants). The bone level measured mesially and distally was in 93.40% of all cases between the implant shoulder and the first thread. The present study shows that the immediate functional loading of immediate implants without the use of any bone substitutes or barrier membranes for fixed complete-arch reconstructions can be successful over a 2-year period.

Stability of the mucosal topography around single-tooth implants and adjacent teeth: 1-year results.

This study evaluated the soft tissue stability around 10 single-tooth implants. All cases were treated following the same protocol, which included guided bone regeneration and connective tissue grafting. One year after prosthesis insertion the soft tissue shrinkage on the buccal side of the implant crown was 0.6 mm on average. The soft tissue volume in the papilla area increased on average by 0.375 mm, and none of the papillae lost volume.

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.

Implant-tissue interfaces following treatment of peri-implantitis using guided tissue regeneration: a light and electron microscopic study.

This study details the structural and ultrastructural features of the interfaces between titanium implants and their surrounding tissues. The material stemmed from an experiment in dogs in which guided tissue regeneration with Gore-Tex membranes was used to treat peri-implant, ligature-induced tissue breakdown around submerged and nonsubmerged commercially pure titanium implants. Specimens from the nonsubmerged group were evaluated under light microscopy and scanning and transmission electron microscopy. A healthy gingiva and a gingival sulcus were formed around the implant necks. A regenerated junctional epithelium provided the epithelial union between implant and gingiva. The supracrestal connective tissue was characterized by a 3-dimensional network of collagen fibers, fibroblasts and blood vessels. Near the implant surface the collagen fibers ran parallel to the titanium surface or were orientated perpendicular to the implant. The connective tissue-implant interface was characterized by a fine fibrillar material interposed between the implant surface and the connective tissue. An unidentified material was also observed between the endings of functionally orientated collagen fibrils and the metallic surface. The apical portions of the implants were anchored in compact bone. At the bone-implant interface, either mineralized bone matrix was intimately adapted to the titanium surface without any intervening space or a 0.5-micron wide unmineralized layer was interposed. These findings indicate that a perimucosal seal was formed around the implants consisting of a junctional epithelium-implant union coronally and supported by the connective tissue-implant junction apically. The implants were integrated in connective tissue, but only tightly adapted to bone.

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)