Search PubMed⌕ Search

Biomedical subjects

A Piattelli

Publications and source records attributed to A Piattelli.

At least 37 records · Page 2Linked to original sources
PubMed2001

Angiomyolipoma of the palate. Report of a case.

Angiomyolipoma (AML) is a tumour or an hamartomatous growth that usually affects the kidney. Only rarely has AML been described in the oral cavity. The authors report a case of AML located in the palate in a 43-year-old patient. AML is composed of smooth muscle cells, blood vessels and mature fat cells. In 50% of cases, AML presents with symptoms of tuberous sclerosis. Renal AML are often invasive, may involve regional nodes and may recur, while, on the contrary, AML are most often well circumscribed and easily resected. AML seems to follow an entire benign course.

Actins↗
PubMed2001

Warty carcinoma of the oral mucosa in an HIV+ patient.

The authors present the case of a 36-year-old HIV+ male patient with a 1-cm diameter papillary exophytic lesion of the right cheek. Microscopic examination showed a papillary epithelial neoplasm with invasion of the stroma in the peripheral part. Cellular and nuclear atypia were present in the superficial and in the deep layers of the neoplasm. An in situ hybridization for human papillomavirus (HPV) 6, 11, 16, 18, 31, 35 and 51 was performed. A focal positivity only for HPV 16 and 18 was present in koilocytotic cells of the most peripheral portion of the lesion. The microscopic definitive diagnosis was warty carcinoma of the cheek. No recurrence was observed at a 3-year follow-up.

Adult↗
PubMed2001

Myxoid liposarcoma of the oral cavity with involvement of the periodontal tissues.

BACKGROUND, AIMS: Liposarcoma is the 2nd most frequent soft tissue sarcoma in adults, but it is extremely rare in the head and neck and, particularly, in the oral cavity. We report on a 25-year-old female who presented with a periodontal mass, extended from the right upper 3rd molar to the right upper 2nd premolar, covered by intact oral mucosa. The clinical differential diagnosis included peripheral giant cell granuloma, salivary gland neoplasms, squamous cell carcinoma of the gingiva, sarcoma and malignant lymphoma. METHODS: To accurately plan subsequent treatment, an excisional biopsy was performed and a myxoid liposarcoma was diagnosed. Consequently, the patient underwent wide excision of the neoplasm with maxillary en-block resection. RESULTS: The post-operative course was uneventful and the patient is alive and well 8 years after the original diagnosis. The authors stress the importance of considering soft tissue sarcomas in the diagnostic approach to patients with unusual periodontal neoplasms and to plan adequate surgical sampling of the lesion (i.e. excisional biopsy). CONCLUSIONS: This appears of pivotal importance as more limited specimens may result in inaccurate pre-operative diagnosis.

Adult↗
PubMed2001

Expression of hMSH2 and hMLH1 proteins of the human DNA mismatch repair system in ameloblastoma.

The human DNA mismatch repair (hMMR) system plays an important role in reducing mutation and maintaining genomic stability. The MMR system in human cells is composed of at least six genes (hMSH2, hMLH1, hMSH3, hPMS1, hPMS2 and GTBP/hMSH6). In particular, hMSH2 and hMLH1 are expressed in human cells that are undergoing rapid renewal; their reduced expression has been reported in several tumors. We examined the protein expression pattern of hMSH2 and hMLH1 by immunohistochemistry in 25 ameloblastomas. All ameloblastomas expressed hMSH2 and hMLH1 proteins in the outer layer of epithelial cells. The localization of the staining was exclusively nuclear. These data suggest that the development and progression of these tumors do not depend on a defect in the hMMR system.

Ameloblastoma↗
PubMed2001

Alkaline phosphatase activity in normal and inflamed dental pulps.

Alkaline phosphatase (ALP) seems to be important in the formation of mineralized tissues. High levels of ALP have been demonstrated in dental pulp cells. In the present study ALP activity was analyzed in normal healthy human dental pulps, in reversible pulpitis, and in irreversible pulpitis. Enzymatic ALP control values for the normal healthy pulps were 110.96+/-20.93. In the reversible pulpitis specimens the ALP activity increased almost eight times to 853.6+/-148.27. In the irreversible pulpitis specimens the values decreased sharply to 137.15+/-21.28 and were roughly equivalent to those seen in normal healthy pulps. The differences between the groups (control vs. reversible pulpitis and reversible pulpitis vs. irreversible pulpitis) were statistically significant. These results could point to a role of ALP in the initial pulp response after injury.

Acute Disease↗
PubMed2001

Aspartate aminotransferase activity in human healthy and inflamed dental pulps.

Aspartate aminotransferase (AST) seems to be an important mediator of inflammatory processes. Its role in the progression and detection of inflammatory periodontal disease has been increasingly recognized in recent years. In the present study AST activity was analyzed in normal healthy human dental pulps, in reversible pulpitis, and in irreversible pulpitis. Enzymatic AST activity showed that the control values for the healthy pulps were 4.8 +/- 0.7 units/mg of pulp tissue. In reversible pulpitis specimens the AST activity increased to 7.98 +/- 2.1 units/mg of pulp tissue. In irreversible pulpitis specimens the values decreased to 2.28 +/- 1.7 units/mg of pulp tissue. Differences between the groups (control versus reversible pulpitis and reversible pulpitis versus irreversible pulpitis) were statistically significant (p = 0.0015). These results could point to a role of AST in the early events that lead to development of pulpal inflammation.

Acute Disease↗
PubMed2001

P53 protein expression in odontogenic cysts.

p53 protein seems to be related to the suppression of cell proliferation. p53-positive tissues seem to have a higher proliferative activity than p53-negative ones. Odontogenic keratocyst (OKC) has a different behavior from other types of cysts because it is more aggressive, with a tendency to recurrence. Twenty-two dentigerous cysts, 24 radicular cysts, and 20 OKCs were used in the present study. Two dentigerous cysts (9.1%), 2 radicular cysts (8.3%), and 9 OKCs (45%) expressed the p53 protein. The differences between the three groups were statistically significant (p = 0.003). In 10 cases of OKCs epithelial dysplasia was found. One of the 10 OKCs without dysplasia and 8 of the 10 OKCs with dysplasia were p53-positive: the difference between the two groups was statistically significant (p = 0.007). The overexpression of p53 protein was not on the other hand correlated with the occurrence of multiple, bilateral, and recurrent OKCs. Moreover the distribution of p53-positive cells was parabasal in contrast with other types of cysts. These qualitative and quantitative differences in proliferative activity in OKCs seem to point to an alteration in cell cycle control.

Basement Membrane↗
PubMed2001

Zebra XXII, part 2.

Explore the source record for details and available documents.

Alveolar Process↗
PubMed2001

Clear cell odontogenic carcinoma. Report of two cases and review of the literature.

This study reviews the literature and reports on the morphologic and immunophenotypic features of 2 clear cell odontogenic carcinomas occurring in the mandible of elderly women, showing extensive infiltration into adjacent tissues. The tumor cells were large, with clear cytoplasm, and arranged in irregular sheets. Some of the latter demonstrated a peripheral rim of cells with eosinophilic cytoplasm or included duct-like structures. There was no evidence of ameloblastic differentiation. Most cells contained glycogen granules and were immunoreactive for cytokeratins and epithelial membrane antigen. In the differential diagnosis other clear cell odontogenic, salivary gland, and metastatic tumors should be considered. Both cases were treated with surgical excision, and the patients are free of disease after 3 and 5 years, respectively. In the literature, however, variable behavior of these tumors has been reported, including recurrence and metastases. It is recommended that terms such as clear cell ameloblastoma and clear cell odontogenic tumor not be used to describe such tumors.

Aged↗
PubMed2001

Localized ridge augmentation using titanium micromesh.

Guided bone regeneration (GBR) has been used recently for the regeneration of bone in conjunction with the placement of dental implants, for augmentation of resorbed alveolar crests, and to treat localized ridge deformities. Twenty-two patients with alveolar crest defects or peri-implant dehiscences participated in this study. Titanium implants were inserted, and the defects were covered with a titanium micromesh, above which was positioned an e-PTFE membrane. After healing, the 2 membranes were removed and a small specimen of the underlying tissues was retrieved with a small trephine. The postoperative healing was mostly uneventful, and only a few dehiscences with membrane exposure were observed. The space under the membranes was, in all patients, filled by a tissue with the macroscopic features of newly formed bone. No residual bone defects were observed and an increase of the alveolar width or height was observed. No untoward effects on bone regeneration were observed in the cases with membrane exposure. Histology showed that the underlying regenerated tissues were composed, in all cases, by newly formed bone. In conclusion, our results show that very satisfactory results concerning GBR techniques can be obtained even without the use of grafts under barrier membranes.

Adult↗
PubMed2001

Fluids and microbial penetration in the internal part of cement-retained versus screw-retained implant-abutment connections.

BACKGROUND: It has been recently observed that in implants with screw-retained abutments, in in vitro as well as in vivo conditions, bacteria can penetrate inside the internal cavity of the implant as a consequence of leakage at the implant-abutment interface. An alternative to screw-retained abutments is represented by implants that can receive cemented abutments. In this case, the abutment goes through a transmucosal friction implant extension (collar) and is cemented inside the internal hexagonal portion of the implant. The aim of the present research was to compare fluids and bacterial penetration in 2 different implant systems, one with cement-retained abutments (CRA) and the other with screw-retained abutments (SRA). METHODS: Twelve CRA dental implants and 12 SRA implants were used in this study. The research was done in 3 steps: scanning electron microscopic (SEM) analysis, fluid penetration analysis, and bacterial penetration analysis. RESULTS: 1) Under SEM it was possible to observe in the SRA implants a mean 2 to 7 micron gap between implant and abutment, while in the CRA implants, the gap was 7 micron. In the latter group, however, the gap was always completely filled by the fixation cement. All the spaces between abutment and implant were filled by the cement. 2) With SRA implants, it was possible to observe the presence of toluidine blue at the level of the fixture-abutment interface and the internal threads; the absorbent paper was stained in all cases. With CRA implants, the absorbent paper inside the hollow portion of the implants was never stained by toluidine blue. No penetration of toluidine blue was observed at the implant-abutment interface and inside the hollow portion of the implants. 3) In all the SRA implant assemblies, bacterial penetration was observed at the implant-abutment interface. No bacteria were detected in the hollow portion of the CRA implants. CONCLUSION: On the basis of the results obtained in the present study using 2 different implant systems, we conclude that CRA implants offer better results relating to fluid and bacterial permeability compared to SRA implants.

Cementation↗
PubMed2001

Immediate implantation in fresh extraction sockets. A controlled clinical and histological study in man.

BACKGROUND: Early implantation may preserve the alveolar anatomy, and the placement of a fixture in a fresh extraction socket helps to maintain the bony crest. Although a number of clinical studies exist, no histological reports show the outcome of implantation in fresh extraction sockets without the use of membranes in humans compared to implants placed in mature bone. METHODS: Forty-eight healthy patients, receiving at least 4 fixtures in each of 2 symmetrical quadrants, underwent placement of 1 experimental fixture placed in a fresh extraction socket (TI) and 1 contralateral fixture in mature bone (CI). TI were placed after atraumatical tooth extraction, with a surgical site at the apex of the socket and a tight contact between the fixture and the socket's walls, but without the use of filling materials or membranes. The flap was coronally repositioned to obtain primary wound closure. Immediately after surgical intervention, a standardized periapical radiograph was taken. Second-stage surgery was done after 6 months. Six months after the second surgery, a second standardized periapical radiograph was taken and clinical parameters (bleeding and plaque index) recorded. Marginal bone loss (MBL) from the time of implant placement to the time of fixture removal was calculated by comparing periapical radiographs. TI and CI were then removed by a hollow drill to obtain histological specimens. Non-demineralized sections were stained by acid fuchsin and toluidine blue, and by von Kossa to evaluate the degree of bone mineralization. The percentage of direct implant-bone contact (DBC) was calculated by a computerized microscopic digitizer. RESULTS: No significant differences in the clinical and radiographic parameters were observed between the 2 experimental categories. There was no statistically significant difference between TI and CI for DBC either in the maxilla or in the mandible. No connective or fibrous tissues were present around TI or CI. Bone resorption was not present in any of the histological sections. CONCLUSIONS: The present study shows that when a screw-type dental implant is placed without the use of barrier membranes or other regenerative materials into a fresh extraction socket with a bone-to-implant gap of 2 mm or less, the clinical outcome and degree of osteointegration does not differ from implants placed in healed, mature bone.

Adult↗
PubMed2001

Comparison of calcium sulfate and autogenous bone graft to bioabsorbable membranes plus autogenous bone graft in the treatment of intrabony periodontal defects: a split-mouth study.

BACKGROUND: Current literature shows that calcium sulfate can be used in guided tissue regeneration. Its biocompatibility and resorbability give it significant advantages in the treatment of periodontal and endodontic defects. Clinically guided tissue regeneration procedures have demonstrated significant positive clinical change, beyond that achieved with debridement alone, in treating intraosseous defects. The aim of the present investigation was to evaluate the clinical results obtained with autologous bone plus calcium sulfate, and to compare them with the results obtained using autologous bone plus membrane. METHODS: A total of 12 patients were treated in the present investigation. A split-mouth design was utilized. Twelve 3-wall periodontal defects were treated with calcium sulfate plus autologous bone graft (test) and compared with 12 contra-lateral defects treated with a bioabsorbable membrane plus autologous bone graft (control). Before the surgical procedure, patients were instructed about oral hygiene and scaling and root planing (SRP) was completed. Probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were recorded at baseline and 6 months. RESULTS: There were no statistical differences between test and control defects at baseline. BOP was 58% and 50% for control and test defects, respectively. Mean PD was 7.75+/-0.96 mm (control) and 8.0+/-1.28 mm (test). Mean CAL was 8.58+/-1.31 mm (control) and 8.83+/-0.91 mm (test). At 6 months, mean PD was 3.41+/-0.51 (P = 0.0022) for control defects and 3.58+/-0.51 (P = 0.0022) for test defects. CAL showed a mean gain of 5+/-0.85 for controls (P = 0.0022) and 5.25+/-0.75 for test defects (P = 0.0022). Thus, there was a mean reduction of PD of 4.33 mm (56%) for control sites and 4.42 mm (55%) for test sites. The mean clinical attachment gain was 3.57 mm for control sites and 3.58 mm for test sites. As there were no sham-operated controls, it is not clear that the healing of these test or control-treated sites was any better than similar 3-walled defects sham operated. CONCLUSIONS: Both therapies led to short-term improvement of the measured parameters; neither was superior to the other.

Absorbable Implants↗