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Purpose: Osteoporosis and diabetes are physiologic determinants that affect the process of osseointegration. The demand for dental implants is high in these patients, who have benefited from progress in preclinical research. Osseointegration has been extensively studied in rat models of osteoporosis and diabetes. The aim of this study is to present an assessment of the published data and provide consideration for future studies. Materials and Methods: The present study summarizes information through a systematic review of the literature from 1997 to 2008 available through PUBMED. The authors found 20 and 13 articles that report on osseointegration of implants in osteoporotic and diabetic rats, respectively. The survey was extended to recent publications on relevant aspects related to species, strains, and quality of endpoint data. Results: Differences in experimental variables such as timing of implant insertion, location of implants, or duration of disease prior to implant placement were reported and can be justified based on the experimental questions. Moreover, heterogeneity was further caused by variations in the age of rats and in reporting of the main parameters of osseointegration in the cortical and medullary compartments. Regardless of these differences, the evidence indicates consistently that ovariectomy results in reduced osseointegration, while there is only moderate evidence for impaired osseointegration in diabetic rats. Conclusions: Selection of the appropriate protocol is critical when studying implant osseointegration in rats. This overview highlights the demand for quality endpoint data related to animal numbers, data collection, and the way to establish osseointegration. Because of the differences in research questions, general recommendations for uniform models for osteoporosis and diabetes cannot be made. Int J Oral Maxillofac Implants 2010;25:516-524. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate a novel surgical technique for flapless transcrestal elevation of the maxillary sinus floor via surgical templates using gel pressure. Materials and Methods: Computed tomographic scans of fresh human cadaver maxillae and three-dimensional treatment planning software were used to design surgical templates. Access to the maxillary sinus was gained by guided transcrestal osteotomies to puncture the bony sinus floor. By injection of radiopaque gel, the maxillary sinus membrane was elevated to attain a postoperative bone height of 15 mm. Results: The gel-pressure technique was performed in 10 atrophic maxillary sites with a mean residual bone height of the alveolar crest of 4.7 ± 1.6 mm. The sinus membrane was successfully elevated in all sites without causing iatrogenic perforation (mean elevation height, 10.6 ± 1.6 mm). Conclusions: The gel-pressure technique may provide a new option for minimally invasive transcrestal sinus surgery and may represent a safe method to increase bone volume in the atrophic posterior maxilla. [ABSTRACT FROM AUTHOR]

PURPOSE: Clinical, microbiologic, and immunologic comparisons of the peri-implant health in edentulous volunteers wearing long-standing implant-supported ball- or Dolder bar-retained mandibular overdentures were performed. MATERIALS AND METHODS: Ten age- and gender-matched individuals (mean age, 71 years) with either ball- or bar-retained complete mandibular overdentures, scheduled for an annual implant recall examination, were investigated an average of 7 years after implant placement. Plaque and gingival crevicular fluid samples were obtained from the peri-implant sulcus. The groups were compared with regard to peri-implant probing depth; plaque and bleeding on probing scores; sulcular fluid flow rates; implant stability measurements (Periotest device); relative concentrations of Actinobacillus actinomycetemcomitans, Prevotella intermedia, Fusobacterium nucleatum, Porphyromonas gingivalis, Tannerella forsythensis, and Treponema denticola assessed by polymerase chain reaction analysis; and sulcular concentrations of interleukin-1beta and prostaglandin E2, assessed by enzyme-linked immunosorbent assay. RESULTS: No statistically significant differences were found for any of the examined parameters between both study groups. CONCLUSION: Within the limitations of this study, both ball attachments and Dolder bars can be recommended for overdenture retention, with either one showing satisfying clinical, microbiologic, and immunologic findings in the peri-implant tissues after several years of service in healthy recall patients with good oral hygiene habits. [ABSTRACT FROM AUTHOR]

PURPOSE: In patients with atrophic mandibles, elevation of the floor of the mouth often prevents intraoral rectangular radiography for longitudinal follow-up studies, while extraoral techniques such as panoramic radiographs tend to produce distorted views of the interforaminal region. In this study, intraoral rectangular radiographs and panoramic radiographs were compared for their accuracy in evaluating peri-implant bone loss. MATERIALS AND METHODS: In a recall program, 22 patients with 88 screw-type implants (44 MKII and 44 Frios) were followed. Interforaminal marginal bone loss was evaluated by extraoral orthopantomograms and by intraoral rectangular radiographs. In addition, pocket depth, Periotest readings, and bleeding on probing were recorded. For statistical analysis, the Spearman coefficient of correlation was used. The effects on bone loss and clinical variables were computed with a mixed model and the Bland and Altman method. RESULTS: Computed as least square means, the mean difference between panoramic radiographs (2.4 +/- 0.2 mm for MKII implants and 1.6 +/- 0.2 mm for Frios implants) and intraoral radiographs (2.6 +/- 0.2 mm and 1.4 +/- 0.2 mm, respectively) was 0.2 mm (range, 0.1 to 0.8 mm). DISCUSSION: In this study, the 2 imaging techniques were comparable clinically in terms of the precision with which they could be used to measure marginal bone loss. CONCLUSION: For highly atrophic mandibles with unfavorable imaging conditions, rotational panoramic radiographs can be a useful alternative to intraoral small-format radiographs for evaluating peri-implant bone loss. [ABSTRACT FROM AUTHOR]

The aim of this article was to present the experimental peri-implantitis models described in the literature and to provide a review of currently used treatment methods. For this purpose, 29 English- and German-language studies published in internationally reviewed journals were examined for similarities and differences regarding animal models, types of implants, and methods used for inducing peri-implantitis. In almost all studies, the implants were located in the mandible, which suggests that peri-implantitis of the maxilla has been researched very little. While in most studies, peri-implantitis was induced by means of ligature and plaque accumulation, only 3 studies have been published that attempted to induce peri-implantitis by means of mechanical overload. Of the latter, only one author observed peri-implant bone resorption. Eleven studies reporting on ligature-induced peri-implantitis presented enough data to be subjected to further statistical data analyses. Meta-analysis revealed that the period of ligature application, and thus the duration of plaque accumulation, generally had no influence on the resultant depth of the bone defect. However, when screw-type and cylindric implants were analyzed separately, a weakly significant positive effect of the duration of ligature application on the resultant defect depth was determined for cylindric implants (P = .092). This could imply that smooth screw-type implants were less susceptible to ligature-induced peri-implant inflammation. Regenerative treatment methods included the membrane technique using non-resorbable membranes (guided bone regeneration), augmentation with autogenous bone, augmentation with bone substitute materials (hydroxyapatite or demineralized freeze-dried bone) or with recombinant human bone morphogenetic protein-2, and a combination of membrane and augmentation procedures. While all described methods resulted in acceptable bone gain, it seems to be difficult to achieve new osseointegration (reosseointegration) of treated implants. Of all tested treatment methods, the combination of guided bone regeneration and augmentation with demineralized freeze-dried bone resulted in the most favorable results regarding bone gain and reosseointegration. [ABSTRACT FROM AUTHOR]