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Implant impression and transfer of the implant position to a working cast for rehabilitative purposes not always represent a predictable reconstructive step. The variable results depend on the transfer technique utilized and on the accuracy of the impression materials. The aim of this study was to compare the accuracy of the direct and indirect impression techniques and to analyze the distortion of different impression materials. An edentulous acrylic resin mandible was used as reference model: in the cuspid position 2 laboratory analogs were inserted perpendicularly to the occlusal plane and fastened with resin. Two impressions for each indirect and direct recording techniques with 4 different impression materials were made. Polyvinyl siloxanes were used for the repositioning implant level method. Polyethers were used for the ''pick up'' impression technique. Analysis of cast distortion was measured computing the inter-implant position on the developed models compared to that of the master model. Measurements were recorded by a digital caliper. The results of this in vitro study demonstrate that the direct impression technique is preferable to the indirect one and that the Impregum polyether impression material is the most precise when used in association with a direct technique.

Aim: The implant/abutment interface represents a crucial element to maintain the structural stability of the implant restoration and to prevent mechanical problems that can compromise the long-term success of the implant treatment., Methods: In this study deformation of the external hexagonal and internal octagonal extension of 2 implants after applying different values of insertion torque has been tested. The implants were secured in a customized resin baseplate, with the implant neck exposed, then different values of insertion torque were applied by an electronic torque controller., Results: Five internal octagonal implants were tested for 60 seconds to different torque magnitudes (12 Ncm, 21 Ncm, 27 Ncm, 36 Ncm, 42 Ncm). Two external hexagonal implants were tested for 60 seconds to a torque value of 27 Ncm and of 36 Ncm., Conclusions: After torquing tests, each implant was examined by a scanning electron microscope (SEM) medium and high magnification to evaluate the deformation of the 2 different antirotational systems. The SEM analysis of the internal octagonal and external hexagonal antirotational systems of the TBR implant showed a deformation proportional to the magnitude of the applied torque during implant insertion. The geometric deformation of the antirotational extension is capable of compromising its function after a torque magnitude of 36 Ncm or superior to this value. Moreover it was demonstrated a more evident alteration of the external hexagonal extension in comparison with the octagonal system after applying a torque value of 27 Ncm.

Biphosphonates are a large class of drugs which inhibits the resorbing activity of osteoclasts. The aim of this study was to evaluate the influence of topical application of the biphosphonate alendronate on the integration process of endosseus implants placed in a partially edentulous patient. After incision and elevation of a mucoperiosteal flap and carrying out the osteotomy, 2 SLA implants 10 mm long and 3.5 mm wide were inserted in the area of # 4.5 and 4.6. Before placement of # 4.5, a paste made of grinded tablets of alendronate and Rifocin was applied in the osteotomy. Fifteen days after stage I, an evaluation of the osteoblastic peri-implant activity was carried out using single photon emission computerized tomography. Healing was within normal limits. Four months after stage I, the 2 implants were uncovered and considered clinically and radiographically integrated. The osteoblastic activity was judged similar bet-ween the 2 implants in terms of quality of biological response. Osseous scintigraphy and the achievement of implant osseointegration demonstrate the lack of toxicity of the topical application of the biphosphonate alendronate during the initial osseous healing. However, new experimental studies and clinical trials are necessary to confirm the results obtained.

Oral mucosa is frequently involved in a group of genetic diseases, which affect the skin and other organs, particularly the central nervous system. The lesions may be of characterized by inflammations in neurocutaneous syndromes and by tumoral lesions in those diseases with defects of DNA repair. The teeth are mainly involved in progeria, while jaw keratocysts are highly characteristic in Gorlin's syndrome.

A wide range of hereditary anomalies, characterized by hair defects and only partially known from the genetics point of view, involves the teeth and oral mucosa with particular features. Teeth alterations are extremely heterogeneous; very frequently gums, palate, tongue and lips are affected. Waiting for a more comprehensive genetic definition and classification, these anomalies are grouped according to the hair defect (hypotrichosis, hypertrichosis and mixed-type).

Oral implantology is considered an acceptable treatment modality to replace missing teeth when a recipient site with a sufficient horizontal and vertical bone volume exists. Guided bone regeneration is based on the principle of selective exclusion of non osteogenic cells from the bony defect by a barrier membrane. Several supporting systems of the barrier membrane have been successfully used to treat non space-mantaining de-fects. A 35-year-old female affected by a partial edentulism in the molar area of the right mandible showed 8 mm of bone height of the residual ridge above the alveolar canal. A vertical ridge augmentation was performed using a Gore-Tex membrane in conjunction with a microplate and an irradiated freeze-dried cortico-cancellous allograft. Six months after the surgical procedure a 11.5 mm by 5 mm threaded implant was placed into the regenerated bone. After three months of healing, the implant was uncovered and considered integrated. Before the implant placement, a biopsy of the regenerated bone was arried out by a triphine. The histological examination of the bony core showed the attainment of biological goals of guided bone regeneration. The surgical technique followes in this case report has been effective in regenerating a vertical bone volume sufficient for implant treatment.

Background: A large number of oral cancer patients shows poor or partial response to chemotherapy and the mechanisms are poorly understood. Glutathione-S-transferase (GST) is one of the molecules involved in resistance to natural product-based chemotherapeutics. It is an enzyme able to conjugate several substances (metabolites, drugs) to reduct glutathione. Today several isoenzymes of GST are known: GST-alpha, GST-mu, GST-pi, GST-theta. Over-expression of glutathione S-transferase-pi class isozyme is often associated with malignant transformation. Several studies reported that GST-pi staining patterns and their distribution may be helpful in identifying high-risk oral lesions. However, GST is surely involved in resistance to alchilant agents., Objective: To verify the possibility of implication of GST in oral cancerogenesis and in natural chemioresistance, the authors examined the protein expression patterns by immunohistochemistry in paraffin-embedded specimens of primary untreated oral cancers (OSCC)., Methods: GST-a and GST-pi expression in 17 cases of OSCC at different degree of cellular differentiation have been evaluated by immunohistochemistry., Results: The GST-pi expression in primary tumours predominantly varied from mild to moderate levels. The GST-a expression was often quite similar to GST-pi expression with a few exceptions., Conclusions: Expression of GST enzymes is an important signal for multidrug resistance: positive staining for both GST-pi and GST-a could constitute a hallmark of chemoresistant groups of OSSC.