Maurizio S. Tonetti

Determination of the Success and Failure of Root-Form Osseointegrated Dental Implants

Permucosal osseointegrated dental implants are a highly effective and predictable treatment modality for edentulism. This review discusses some controversial aspects of the definitions for success and failure of root-form dental implants. The discussion will focus on the underlying pathologies that, if untreated, may lead to loss of the implanted device. Few clinical syndromes are described based on human pathological material and clinical presentation. The theoretical chronological relationship between implant loss and the incidence of pathology of the soft- and hard-tissue seal around implants is also discussed. The review also examines the finding that implant failures are not randomly distributed in the treated populations and that implant loss clusters in specific high-risk groups and individuals. Known risk indicators, and possible risk factors, are discussed, taking into account the patient, the reconstruction, the implant, and implant site-specific factors. Particular emphasis is placed on the need for better determination of whether periodontal patients are at higher risk for implant failures as a consequence of their increased susceptibility to infectious, inflammatory-response-driven tissue breakdown.

Expression of the cutaneous lymphocyte antigen and the αIELβ7 integrin by intraepithelial lymphocytes in healthy and diseased human gingiva

Abstract The presence of specific phenotypes of intraepithelial lymphocytes (IEL) was determined in healthy and diseased gingiva by immunohistochemistry. The cutaneous lymphocyte antigen (CLA) and the α IEL β 7 integrin were detected with the HECA-452 and with the HML-1 monoclonal antibodies, respectively. Some 24–62% of CD3-positive intraepithelial lymphocytes expressed the CLA antigen in the junctional epithelium, while 49–54% expressed the α IEL β 7 integrin. Similar results were obtained in the other gingival epithelia. The fraction of CLA-positive T cells and α IEL β 7 integrin-positive T cells was significantly higher in the gingival epithelia than in the underlying connective tissue, indicating that the T-cell subsets defined by these surface adhesion molecules were selectively localized in the epithelial compartment. Comparison of the fractions of CLA-positive and α IEL β 7 integrin-positive T cells across different disease groups did not show significant differences. The data indicate that intraepithelial lymphocytes expressing the CLA and the α IEL β 7 phenotype are a quantitatively important component of gingival intraepithelial immunity. These adhesion molecules may play a part in the retention of specific T-cell subsets in gingival epithelia.