Daniel Brandizzi

Reactive lesions of peri-implant mucosa associated with titanium dental implants: a report of 2 cases

The aim of this study was to report 2 novel clinical cases of reactive lesions of the peri-implant mucosa associated with titanium dental implants where metal-like particles were observed histologically. In both cases, the lesions were diagnosed as epulis, based on clinical evidence. Extirpation biopsies were carried out. Case 1 was diagnosed as pyogenic granuloma and case 2 as peripheral giant cell granuloma. The presence of metal-like particles in the tissues suggests that the etiology of the lesions might be related to the corrosion process of the metal structure. This is the first case of pyogenic granuloma to be reported in association with dental implants. All clinical cases of soft tissue lesions associated with implants should be reported to contribute to the understanding of the etiology and pathogeny of these lesions.

Oral Mucosa Tissue Response to Titanium Cover Screws

BACKGROUND Titanium is the most widely used metal in dental implantology. The release of particles from metal structures into the biologic milieu may be the result of electrochemical processes (corrosion) and/or mechanical disruption during insertion, abutment connection, or removal of failing implants. The aim of the present study is to evaluate tissue response of human oral mucosa adjacent to titanium cover screws. METHODS One hundred fifty-three biopsies of the supra-implant oral mucosa adjacent to the cover screw of submerged dental implants were analyzed. Histologic studies were performed to analyze epithelial and connective tissue as well as the presence of metal particles, which were identified using microchemical analysis. Langerhans cells, macrophages, and T lymphocytes were studied using immunohistochemical techniques. The surface of the cover screws was evaluated by scanning electron microscopy (SEM). RESULTS Forty-one percent of mucosa biopsies exhibited metal particles in different layers of the section thickness. Particle number and size varied greatly among specimens. Immunohistochemical study confirmed the presence of macrophages and T lymphocytes associated with the metal particles. Microchemical analysis revealed the presence of titanium in the particles. On SEM analysis, the surface of the screws exhibited depressions and irregularities. CONCLUSIONS The biologic effects seen in the mucosa in contact with the cover screws might be associated with the presence of titanium or other elements, such as aluminum or vanadium. The potential long-term biologic effects of particles on soft tissues adjacent to metallic devices should be further investigated because these effects might affect the clinical outcome of the implant.

Expression of ezrin and metastatic tumor antigen in osteosarcomas of the jaw

Aims and background Ezrin is a membrane-cytoskeleton linker protein involved in regulation of the growth and metastatic behavior of cancer cells. Metastatic tumor antigen (MTA) is a potential metastasis-associated protein. The objective of this study was to evaluate the expression of ezrin and MTA and their correlation with clinico-pathological features in osteosarcomas of the jaw. Methods We analyzed ezrin and MTA protein levels by immunohistochemistry in 31 osteosarcomas of the jaw. Results The mean age at diagnosis was 39 years and half of the patients were male. The mandible (n = 19) was more frequently involved than the maxilla (n = 12). The predominant histological type was chondroblastic (58.1%) and 24 patients (77.4%) were classified as having a high grade of malignancy. Immunoreactivity for ezrin was identified in 6 of 31 cases (19.4%), while 77.4% displayed expression of MTA. All ezrin-positive patients had high-grade tumors. The high-grade tumors (n = 24) had a higher rate of MTA expression (42.9% vs 87.5%). Expression of ezrin and MTA was not significantly different according to age, sex, tumor site, histological type, and tumor ploidy. Follow-up information was available for 13 patients, with a mean follow-up time of 26.7 months (range, 6–48 months). At the time of last follow-up, 5 (38.5%) patients had died of disease and 8 patients (61.5%) were alive with no evidence of disease. Expression of ezrin and MTA was not significantly different according to the follow-up data. Conclusions In our study, high-grade tumors had a higher rate of ezrin and MTA expression. This expression pattern indicates that ezrin and MTA positivity can be additional prognostic markers in osteosarcoma of the jaw.

Histopathological features of osteonecrosis of the jaw associated with bisphosphonates

lomas show a CD163 pattern different from those of the other two granuloma types. Interestingly, Th2-type schistosomiasis-induced granulomas and FB-induced granulomas did not show any significant staining difference. As Th2 responses are thought to have antiinflammatory actions, it is feasible that proinflammatory activity against inert, non-degradable FB material is down-regulated by the host after a phase of recognition. This fits with the notion that the memory component of adaptive immunity is absent in FBinduced granulomas. We were not able to investigate spatial and temporal differences in the expression of the studied markers, as this information can hardly be obtained from human studies. We cannot rule out the possibility that CD163 expression might be different in Th1-mediated and Th2-mediated granulomas at different points in time. The present results obtained with human tissue are in accordance with established rodent models for these diseases, and provide some rationale for the idea that the so-called non-immunologically granulomas provoke an active anti-inflammatory response by the host that has Th2 characteristics and, despite the historical classification, have also to be considered as ‘immunological’.

Ploidy study in oral carcinomas: use of improved methodology to assess its clinical prognostic value

OBJECTIVE This study reports a ploidy analysis in oral squamous cell carcinomas (SCC) using methodologic adjustments to improve the accuracy of the measurements and derive numeric indices of aggressiveness of prognostic value. STUDY DESIGN Sixty-seven SCC were assessed by DNA image cytometry in the areas of the histologic sections with most atypia. Five indices of aggressiveness were analyzed in relation to the clinical-pathologic data and evolution of the patients. RESULTS The mean value of the index of deviation from the diploid value (2cDi) and malignancy index (Mi), taken as a cut-off value, defined 2 populations with statistically significant differences in survival. In patients with tumors in clinical stages III and IV (TNM classification), the Mi also exhibited prognostic value. CONCLUSIONS The 2cDi and Mi can be used, under certain methodologic conditions, as an objective indicator of prognostic value of the degree of aggressiveness of oral SCC.