Mombelli A, Van Oosten MAC, Schiirch E, Lang NP. The microbiota associated with successful or failing osseointegrated titanium implants. Oral Microbiol Immunol 1987: 2: 145-151. Abstract -In this study the microbiota associated with oral endosteal titanium hollow cylinder implants (ITI) was studied using microscopic, immunochemical and cultural methods. Samples from 5 edentulous patients with successfully incorporated implants serving as abutments for overdentures for more than one year were compared with samples from 7 patients with clinically failing implants. Unsuccessful sites were characterized by pocket probing depths of 6 mm or more, suppuration and visible loss of alveolar bone around the implant as visualized on radiographs. These sites harbored a complex microbiota with a large proportion of Gram-negative anaerobic rods. Black-pigmented Bacteroides and Fusobacterium spp. were regularly found. Spirochetes, fusiform bacteria as well as motile and curved rods were a common feature in the darkfield microscopic specimens of these sites. Control sites in the same patients harbored small amounts of bacteria. The predominant morphotype was coccoid cells. Spirochetes were not present, fusiform bacteria, motile and curved rods were found infrequently and in low numbers. The microbiota in control sites in unsuccessful patients and in site in successful patients were very similar. On the basis of these results, it is suggested that "periimplaiuitis" be regarded as a site specific infection which yields many features in common with chronic adult periodontitis.

Background: Peri-implant diseases present in two forms -peri-implant mucositis and peri-implantitis. Materials and Methods: The literature was systematically searched and critically reviewed. Four manuscripts were produced in specific topics identified as key areas to understand the microbial aetiology and the pathogenesis of peri-implant diseases and how the implant surface structure may affect pathogenesis. Results: While peri-implant mucositis represents the host response of the peri-implant tissues to the bacterial challenge that is not fundamentally different from gingivitis representing the host response to the bacterial challenge in the gingiva, peri-implantitis may differ from periodontitis both in the extent and the composition of cells in the lesion as well as the progression rate. A self-limiting process with a "protective" connective tissue capsule developing appears to dominate the periodontitis lesion while such a process may occasionally be lacking in peri-implantitis lesions. Bacterial biofilm formation on implant surfaces does not differ from that on tooth surfaces, but may be influenced by surface roughness. Nevertheless there is no evidence that such differences may influence the development of peri-implantitis. Conclusion: It was agreed that clinical and radiographic data should routinely be obtained after prosthesis installation on implants in order to establish a baseline for the diagnosis of peri-implantitis during maintenance of implant patients.

In the present multi‐center study. non‐submerged ITI implants were prospectively followed to evaluate their long‐term prognosis in fully and partially edentulous patients. In a total of 1003 patients, 2359 implants were consecutively inserted. Following a healing period of 3–6 months, the successfully integrated implants were restored with 393 removable and 758 fixed restorations. Subsequently, all consecutive implants were documented annually up to 8 years. At each examination, the clinical status of all implants was evaluated according to predefined criteria of success. Therefore, the data base allowed the evaluation of 8‐year cumulative survival and success rates for 2359 implants. In addition, cumulative success rates were calculated for implant subgroups divided per implant type, implant length. and implant location. Furthermore, the actual 5‐year survival and success rates could be determined for 488 implants. During the healing period, 13 implants did not successfully integrate, whereas 2346 implants fulfilled the predefined criteria of success. This corresponds with an early failure rate of 0.55%. During follow‐up, 19 implants were classified as failures due to several reasons. In addition, 17 implants (= 0.8%) demonstrated at the last annual examination a suppurative periimplant infection. Including 127 drop out implants (= 5.4% drop out rate) into the calculation, the 8‐year cumulative survival and success rates resulted in 96.7% and 93.3%, respectively. The analysis of implant subgroups showed slightly more favorable cumulative success rates for screw type implants (> 95%) compared to hollow‐cylinder implants (91.3%). and clearly better success rates for mandibular implants (= 95%) when compared to maxillary implants (= 87%). The actual 5‐year survival and success rates of 488 implants with 98.2% and 97.3%. respectively, were slightly better than the estimated 5‐year cumulative survival and success rates of 2359 implants indicating that the applied life table analysis is a reliable statistical method to evaluate the long‐term prognosis of dental implants. It can be concluded that non‐submerged ITI implants maintain success rates well above 90% in different clinical centers for observation periods up to 8 years.

OBJECTIVES: The objective of this systematic review was to assess the 5-year survival of implant-supported single crowns (SCs) and to describe the incidence of biological and technical complications. METHODS: An electronic MEDLINE search complemented by manual searching was conducted to identify prospective and retrospective cohort studies on SCs with a mean follow-up time of at least 5 years. Failure and complication rates were analyzed using random-effects Poisson's regression models to obtain summary estimates of 5-year proportions. RESULTS: Twenty-six studies from an initial yield of 3601 titles were finally selected and data were extracted. In a meta-analysis of these studies, survival of implants supporting SCs was 96.8% [95% confidence interval (CI): 95.9-97.6%] after 5 years. The survival rate of SCs supported by implants was 94.5% (95% CI: 92.5-95.9%) after 5 years of function. The survival rate of metal-ceramic crowns, 95.4% (95% CI: 93.6-96.7%), was significantly (P=0.005) higher than the survival rate, 91.2% (95% CI: 86.8-94.2%), of all-ceramic crowns. Peri-implantitis and soft tissue complications occurred adjacent to 9.7% of the SCs and 6.3% of the implants had bone loss exceeding 2 mm over the 5-year observation period. The cumulative incidence of implant fractures after 5 years was 0.14%. After 5 years, the cumulative incidence of screw or abutment loosening was 12.7% and 0.35% for screw or abutment fracture. For supra-structure-related complications, the cumulative incidence of ceramic or veneer fractures was 4.5%. CONCLUSION: It can be concluded that after an observation period of 5 years, high survival rates for implants and implant-supported SCs can be expected. However, biological and particularly technical complications are frequent. AbstractObjectives:The objective of this systematic review was to assess the 5 year survival of implant supported single crowns (SCs) and to describe the incidence of biological and technical complications. Methods:An electronic Medline search complemented by manual searching was conducted to identify prospective and retrospective cohort studies on SCs with a mean follow-up time of at least 5 years. Failure and complication rates were analyzed using random-effects Poisson regression models to obtain summary estimates of 5-year proportions. Results:Twenty-six studies from an initial yield of 3601 titles were finally selected and data were extracted. In a meta-analysis of these studies survival of implants Periimplantitis and soft tissue complications occurred in 9.7% of the SCs and 6.3% of the implants had bone loss exceeding 2 mm over the 5 years observation period. Technical complications included implant fractures, connection-related and supra-structure related complications. The cumulative incidence of implant fractures after 5 years was 0.14%. After 5 years the cumulative incidence of connection-related complications was 12.7% for screw or abutment loosening and 0.35% for screw or abutment fracture. For supra-structure related complications the cum...

Osseointegration represents a dynamic process both during its establishment and its maintenance. In the establishment phase, there is a delicate interplay between bone resorption in contact regions (between the titanium body and mineralized bone) and bone formation in 'contact- free' areas. During the maintenance phase, osseointegration is secured through continuous remodeling and adaptation to function.