Leiomyosarcoma of the tongue: a case report.
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Actins↗
Biomedical subjects
A Piattelli
Publications and source records attributed to A Piattelli.
Bacterial penetration in vitro through GTAM membrane with and without topical chlorhexidine application. A light and scanning electron microscopic study.
Premature exposure of membrane in the oral cavity is considered the most common complication as well as a reason for failure or incomplete success of guided tissue regeneration, as the exposed membrane undergoes plaque accumulation. A method to control, or at least to reduce the bacterial invasion of the membrane allowing a delay in the membrane removal, could be of clinical interest. The purpose of the present study was to evaluate the possibility of treating, with topical chlorhexidine application, the bacterial colonization of exposed membranes. A special device was developed in order to evaluate, under an experimental environment, the bacterial colonization. This device was made from a removable acrylic denture base to which 5 gold cups were attached. The cups consisted of an internal compartment, isolated from the oral cavity by a GTAM membrane, and an external compartment exposed to the oral environment. 3 healthy subjects had this device fitted, bilaterally, in the molar-premolar region of the upper jaw. The cups of one side of each subject had 0.2% chlorhexidine gluconate gel applied 2x a day for 1 min, whereas those of the other side served as controls. 12 cups were removed after 2 weeks and the remainder removed after 1 month. The non-treated control specimens were characterized by greater amounts of plaque accumulation. In all the test sites, plaque deposits increased in thickness and quantity during the 4 weeks of the experiment. Complete invasion of the membrane and initial colonization of its internal surface were observed only in 4-week specimens. A relatively simple flora consisting mainly of cocci and short rods, was found in bacterial deposits forming under the influence of chlorhexidine, whereas in non-treated specimens, it was possible to observe a more mature and complex plaque, composed mostly of filamentous bacteria. In conclusion, topical application of chlorhexidine gel is an effective method of reducing plaque and calculus formation on the surface of GTAM membranes exposed to the oral cavity for up to 4 weeks. This study has, however, failed to demonstrate the capacity of chlorhexidine to prevent or to retard bacterial penetration through the thickness of the inner portion of the membranes.
Acrylic Resins↗
Eosinophilic granuloma of the mandible involving the periodontal tissues. A case report.
This case reports on a 14-year-old boy with multiple radiolucent lesions widely distributed in the mandible, particularly in the right side (body-angle-ascending ramus). The lesion was first diagnosed as early-onset periodontitis and treated accordingly. It continued to grow very quickly, however, over a 6-month period, resulting in involvement of the entire mandible, with complete destruction of the lingual cortical bone, erosion of the external cortex with expansion in the neighboring soft tissues, and with a periosteal reaction in some areas. This case may serve to illustrate the rapid progress of eosinophilic granuloma, the importance and the difficulties of an early diagnosis, and the consequences of late diagnosis and treatment.
Adolescent↗
Osteoma of the mandible. A case report.
The authors present a case of osteoma of the mandible. Osteomas are solitary lesions occurring predominantly in the skull and many authors believe that most osteomas in the maxillofacial areas are reactive bone hyperplasia or advanced ossifications. In some countries the prevalence of the osteoma is about 1% of all patients in the ENT clinics. Malignant transformation has not been described and surgery of the lesion should be conservative and consist essentially of enucleation.
Adult↗
Soft palate metastasis from a small cell carcinoma of the lung.
Metastases in the oral soft tissues are rare. They usually occur in the tongue and in the gingiva. The most common primary sites for lesions metastasizing to the oral tissues are lung, kidney, stomach, liver. The lung tumors are in the majority squamous cell carcinomas or adenocarcinoma; only rarely the primary tumors are small cell carcinomas. Small cell carcinoma is a highly malignant neoplasm with often extrathoracic metastases at the time of diagnosis, and a very low 5-years survival. Metastases from an occult lung carcinoma should always be considered in the differential diagnosis of small cell carcinomas in extrapulmonary sites.
Carcinoma, Small Cell↗
Microbiological evidence of Helicobacter pylori from dental plaque in dyspeptic patients.
To evaluate the possible route of transmission of Helicobacter pylori, stomach biopsies and dental plaques were cultured from patients with dyspeptic symptoms who underwent endoscopy. A total of 31 patients were examined. Twenty patients out of thirty one (64%) were H. pylori positive in gastric biopsy. Among the microorganisms isolated in dental plaque only one sample (corresponding to a patients with duodenal ulcer H. pylori positive) showed colonies morphologically and biochemically compatible with H. pylori. Proteic patterns of whole cells and restriction endonuclease analysis with Hind III and Hae III endonucleases of DNA extracted from the strain subcultured from a stomach biopsy and from dental plaque of the same patient indicated that both sites were infected with the same strain of H. pylori.
Adult↗
A light and laser scanning microscopy study of bone/hydroxyapatite-coated titanium implants interface: histochemical evidence of unmineralized material in humans.
The authors describe a light and laser scanning microscopy study of hydroxyapatite-coated titanium implants retrieved from humans. A histochemical technique, using von Kossa and basic fuchsin, allowed clear differentiation between mineralized bone and unmineralized bone matrix. The bone-hydroxyapatite (HA) interface presented variable features: in some areas the mineralized bone was directly apposed to the HA surface, while in others an unmineralized red-stained material, probably osteoid, was interposed. Laser scanning microscopy confirmed these findings showing a thin layer of fluorescent material at the interface.
Bone and Bones↗
Histochemical and confocal laser scanning microscopy study of the bone-titanium interface: an experimental study in rabbits.
The aim of our study was an analysis of the presence of an unmineralized bone matrix between mineralized bone and titanium screws in rabbit tibiae. A microscopical analysis, using a histochemical technique, was performed on the titanium-bone interface of commercially pure titanium implants placed in rabbit tibiae and harvested after 2 months. Thin ground sections of the specimens were prepared by the cutting-grinding system and stained using the von Kossa method for calcium salts and basic fuchsin for osteoid. The microscopical and morphometrical evaluation showed that bone covered about 40% (+/- 7.5%) of all implants. Mineralized bone was, however, in direct contact with the titanium surface on only about 10% of the implant, while in the remaining 30% the mineralized bone was separated from the implant by an unmineralized tissue. This basophilic, probably osteoid matrix, could represent the medium that allows the biochemical exchanges between bone and cells under the influence of the implant. A small, optically translucent gap (1-5 microns), probably an artifact, was present in some areas between titanium and bone. Confocal laser scanning microscopy (CLSM) in a fluorescent mode showed the presence at the interface of a fluorescent material. Results from our study showed that light microscopy of thin ground sections allowed a good analysis of the real nature of the titanium-bone interface. Moreover, this double staining technique showed the presence of an unmineralized bone matrix at most of the bone-titanium interface.
Animals↗
Clear cell odontogenic carcinoma. Report of a case with lymph node and pulmonary metastases.
The authors present a case of a rare type of odontogenic tumour, recently described as "clear cell odontogenic tumour". The patient died 5 years after the initial diagnosis with lymph node and diffuse pulmonary metastases. This fact can support the view that this tumour, histologically characterised by the presence of cells with a clear cytoplasm, can behave in an aggressive way and has true metastatic potential, despite the absence of malignant cellular features.
Adenocarcinoma, Clear Cell↗
Freeze-dried dura mater for guided tissue regeneration in post-extraction dental implants: a clinical and histologic study.
Soft membranes were used in 69 patients for bone regeneration around implants (blades and screws, submerged and non-submerged) placed into extraction sockets. In about 10% of the patients a prosthetic restoration was completed immediately, while in the remaining patients the prostheses were connected after a healing period of 3 to 6 months; follow-up ranged from 6 to 30 months. In 22 patients a re-entry procedure was done to evaluate the membrane and in 4 patients a bone biopsy was taken from 3 to 6 months after the placement of the membrane. In all cases the peri-implant tissues appeared clinically healthy and it was possible to see radiographically that the newly formed bone closely adapted to the implants. In most cases it was possible at 6 months re-entry to see the membrane and detach it from the underlying tissues. There was a partial dehiscence of the membrane in only 4% of the cases. After 3 months the tissue under the membrane presented macroscopical features similar to mature bone, and bone biopsies in all cases showed a spongious lamellar bone with a high level of activity and a wide band of osteoid tissue.
Adult↗
A preliminary report on a method for studying the permeability of expanded polytetrafluoroethylene membrane to bacteria in vitro: a scanning electron microscopic and histological study.
The technique of guided tissue regeneration using expanded polytetrafluoroethylene (ePTFE) membranes has been shown to be effective in implant dentistry (bony defects, extremely thin alveolar ridges, and implants placed in fresh extraction sockets). One of the drawbacks associated with the use of membranes is their premature exposure with consequent bacterial contamination. The aim of this study was to examine the possibility that oral bacteria migrate through the occlusive portion of ePTFE membranes and to determine the time needed for microorganisms to pass from the outer surface to the inner surface of the membranes. A removable acrylic device was adapted to the molar-premolar region of one quadrant of the jaws in each of three volunteers. Five cylindrical teflon chambers were glued to the buccal aspect of each device. The chambers were divided into two rooms separated by the inner portion of a ePTFE membrane. The outer room was open to the oral cavity allowing plaque accumulation; the inner room was isolated from the oral cavity by the ePTFE membrane. One of the 5 chambers was completely closed and used as control. The test period lasted for 4 weeks. Every week, one chamber was removed from each device and processed for scanning electron microscopic and histologic examinations. Our study showed the possibility that oral bacteria may contaminate ePTFE membranes exposed to the oral cavity. One specimen showed partial bacterial penetration after 2 and 3 weeks, but after 4 weeks, all membrane specimens demonstrated bacterial contamination.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Composite resin-amalgam compound restorations.
Extensive silver amalgam restorations in premolars and molars occasionally require sacrifice of healthy unsupported enamel walls or cusps. A posterior composite resin-amalgam compound technique has been proposed to conserve these structures. Microleakage was high at the enamel-amalgam interface, moderate at the composite resin-silver amalgam and dentin-composite resin interfaces, and minimal between the inner enamel and the composite resin. Light microscopy and scanning electron microscopy demonstrated that marginal adaptation of the silver amalgam to the composite resin of the cusps was acceptable and that penetration of the inner etched enamel to the composite resin was complete.
Bicuspid↗
Vertical ridge augmentation using a membrane technique associated with osseointegrated implants.
The purpose of this study was to evaluate: (1) the surgical protocol, effectiveness, and reliability for vertical ridge augmentation using a new titanium-reinforced membrane and osseointegrated implants; and (2) the histologic characteristics of the interface between a pure titanium implant and newly regenerated human bone. Five patients received 15 conical Brånemark-type implants in six different surgical sites requiring vertical augmentation. The implants protruded 4 to 7 mm from the bone crest. Pure titanium miniscrews (1.3 x 10 mm) were positioned distally to the implants, protruding 3 to 4 mm from the bone level. The implants and the miniscrews were covered with a titanium-reinforced membrane, and the flaps were sutured. Membranes were removed at the stage 2 surgery after 9 months of healing. Measurements of biopsy specimens showed a gain in bone height from 3 to 4 mm. Histologic examination showed that all retrieved miniscrews were in direct contact with bone. Histomorphometric analysis of bone contact gave a mean value of 42.5 +/- 3.6% for five of the six examined miniscrews. The results suggest that the placement of implants protruding 3 to 4 mm from the top of resorbed bone surfaces may result in vertical bone regeneration to the top of the implant cylinder and that the regenerated bone is able to osseointegrate pure titanium implants.
Adult↗
Odontogenic myxoma of the mandible. Report of a case and review of the literature.
The authors describe the case of an odontogenic myxoma occurring in a 30-year-old man and review the literature on the subject. They detail the radiological aspects of this neoplasms, the problems concerning its etiopathogenesis and the different microscopical patterns.
Adult↗
Qualitative and quantitative comparative study on different filling materials used in bone tissue regeneration: a controlled clinical study.
This study compared, in a human model, the ability of (1) expanded polytetrafluorethylene (e-PTFE) membranes plus bone-chip autografts, (2) e-PTFE membranes plus demineralized freeze-dried bone, (3) e-PTFE membranes plus a new form of demineralized allograft bone tissue, and (4) e-PTFE membranes alone to enhance bone regeneration around dental implants placed into recent extraction sockets. The histologic results demonstrated that, in humans, guided tissue regeneration techniques are capable of producing new bone osseointegrated with titanium dental implants. Among the graft materials, autogenous bone provided the densest and the greatest amount of bone formation, but use of demineralized freeze-dried bone and a new form of de-mineralized allogenic bone matrix also improved bone regeneration compared to membranes alone after 6 months of healing.
Alveolar Bone Loss↗
Bone ingrowth into hydroxyapatite coating: a light microscopy and laser scanning microscopy study.
The authors present a description of the presence of organic material inside the hydroxyapatite (HA) coating of Calcitek implants inserted in rabbit tibia. Light microscopy showed that in all specimens a granular basophilic material which was not mineralized was present inside the thickness of the coatings. In two specimens out of 40, a bone-like substance was observed in some areas of the coating, at a distance from the interface. Laser scanning microscopy showed in all specimens an autofluorescence of osteocytes, osteoblasts, of the interface, and inside the coating. The presence of bone could either show an ability of the coating to serve as a scaffold for the newly forming osseous tissue or be a sign of an initial degradation of the HA.
Animals↗
Pulp obliteration: a histological study.
Pulp obliteration is a very rare occurrence that is most frequently caused by trauma. A 58-yr-old female patient had a generalized pulp obliteration that involved all maxillary and mandibular teeth. One tooth was extracted due to an extensive carious lesion and it was processed by a cutting-grinding technique. It was possible to observe the complete obliteration of the pulp chamber, which was filled in part by reparative dentin and in part by a calcified tissue with a concentric layers structure with no tubular pattern. The root canals were almost completely obliterated by an amorphous calcified material.
Dental Pulp Calcification↗
Microscopic and chemical analysis of bone-hydroxyapatite interface in a human retrieved implant. A case report.
The aim of the present study was a histological and chemical analysis of the bone-hydroxyapatite interface in a retrieved human implant. The implant was cut in two: one half was processed for light microscopy with the cutting grinding system, and the other for SEM analysis with EDX and a cathodoluminescence system. Bone maintained an intimate contact with the hydroxyapatite and the bonding of the hydroxyapatite with the metal was very strong. An analysis of the interface from a double staining (basic fuchsin and von Kossa) showed a non-mineralized matrix, interposed between hydroxyapatite and bone in many areas. It is possible that different microscopic features are present in different areas of the interface, however, intimate contact was observed 6 months after insertion of the implant.
Calcium↗