Calcium sulfate barrier for regeneration of human bone defects. 3 years randomized controlled study.

Several experimental studies have been performed in order to evaluate the behavior of different types of biomaterials involved in the process of tissue and bone regeneration. The guided bone regeneration (GBR) principles are applied in the rebuilding of periodontal tissues, damaged by the periodontal inflammatory process. Since the introduction of GBR biological principles, a wide range of materials have been tested and used as a physical barrier. At present, the autogenous material continues to be considered the best choice when reconstruction of bone defects is intended. Calcium phosphate ceramics have been widely applied as bone substitutes, coatings, cements, drug delivery systems and tissue engineering scaffolds due to their resemblance to the mineral portion of the bone tissue, relative ease in processing and good cell attachment. 40 patients (25 males and 15 females) planned to receive bone regeneration procedure were included in the study. 20 patients were treated for bone regeneration using just BondBone, 10 patients using BondBone and a Collagen membrane and the remaining 10 patients with Bone substitute and a collagen membrane. This study has evaluates the bone tissue behavior of calcium sulfate barrier in bone repair in human bone, observing the GBR biological principles. We can conlude that calcium sulfate can work as a completion material, space maintainer, vehicle for a controlled release of certain drugs, associated with other graft materials.

Expression of Vascular Endothelial Growth Factor (VEGF) mRNA in healthy bone tissue around implants and in peri-implantitis.

Peri-implantitis is an inflammatory process involving peri-implant bone. Angiogenesis is critical for the development, remodeling and healing of bone. Vascular Endothelial Growth Factor (VEGF) is a glycoprotein that induces endothelial cell proliferation, angiogenesis and capillary permeability. VEGF is expressed in a variety of highly vascularized tissues and seems to be a prerequisite for tumor growth and invasion. VEGF takes part in bone cell differentiation and by promoting angiogenesis at the site of bone formation. Aim of the present study was an evaluation of VEGF mRNA in bone around healthy and failing dental implants. Twenty patients participated in this study. Twenty bone biopsies were obtained, 10 at second-stage surgery from bone covering the healing screws (control), and 10 from implants presenting the typical signs and symptoms for peri-implantitis lesions (test). VEGF mRNA levels were not present in any of the controls, while it was identified in all tissues obtained from test implants. The difference was statistically significant (p < 0.05). Our results point to the fact that VEGF may be important in the regulation of tissue healing and bone remodeling in the peri-implantitis lesions because VEGF has been reported to play a role in the formation and attraction of osteoclasts, and osteoclasts have been shown to be a prominent feature of the peri-implantitis lesions.

The immediate functional loading of seven and mistral implants with new multi unit titanium abutments. 24 months follow up report.

Immediate loading of dental implants has been defined as a situation where the superstructure is attached to the implants at time of the surgery or however no later than 72 hours after surgery. Micromovements have been deeply studied in dental implants loading but the question of reduction of micromovements has not been addressed in controlled studies dealing with immediate loading of oral implants. Passive fit of provisional prostheses has been mentioned as an important factor in the osseointegration of immediately loaded implants. The ultimate goal of an immediate loading protocol is to reduce the number of surgical interventions and shorten the time frame between surgery and prosthetic delivery, all without sacrificing implant success rates. Aim of this study was to evaluate the use of a new titanium abutments for screw retained prosthesis in edentulous patients in an immediate loading procedure in order to reduct the number of surgical steps.

Clinical and mechanical evaluation of screw-retained implant-supported zirconia restorations. A 36 months prospective clinical study.

This study evaluated the clinical performance of screwed customized zirconia abutments. Additionally, the marginal fit between the selected implant components was measured and the clinical gingival response was monitored. Thirty patients were consecutively selected for a prospective study of 30 implant-supported restorations. Customized zirconia abutment complexes were prepared, then ceramic was performed directly. The abutments were screwed onto the implants and restored with all-ceramic crowns. Plaque and gingival indices were recorded monthly intervals over a 12- month period. All ceramic zirconia abutments offered sufficient stability to support implantsupported single-tooth reconstructions in anterior and premolar regions. The soft and hard tissue reaction toward zirconia was favorable.

Use of bone compressors and atraumatic bone elevators in crestal sinus lift.

Atrophy of the alveolar processes of the jaws, as a result of edentulism, often cannot allow a prosthetic rehabilitation, also if it only consists of a total removable prosthesis - for the inadequate base support - and also if it is backed by implants, because the small residual thickness bone compromises the primary implant stability, a fundamental requirement for a correct osseointegration. In addition to atrophy itself, the presence of noble structures (maxillary sinus, inferior alveolar nerve) make an implant-prosthetic rehabilitation contraindicated. To obviate this problem, there are many techniques to increase bone. The technique of the maxillary sinus elevation allows the increasing of the residual bone up to reach the minimum thickness in order to insert an implant. With this work we want to analyze the properties of the Bone Compression Kit (MIS, Israel) that make this surgical procedure safe, simple to perform, and predictable.

Influence of amine fluoride/stannous fluoride mouthwashes with and without chlorhexidine on secretion of proinflammatory molecules by peri-implant crevicular fluid cells.

AIM: Patients with dental implants need optimal plaque control. Peri-implantitis is an inflammation of soft and hard tissues around implants characterized by bone loss mediated by proinflammatory molecules such as IL-1beta, PGE(2), vascular endothelial growth factor (VEGF). The aim of this study was to evaluate the influence of amine fluoride/stannous fluoride (AmF-SnF(2)) vs chlorhexidine 0.12% (CHX) combined with Am-SnF(2) on IL-1beta, PGE(2) and EGF secretion by cells of crevicular peri-implant fluid. METHODS: Thirty patients with dental implants were included in this study. The test group used AmF-SnF(2) rinsing for 14 days, the control group used CHX rinsing during the first 7 days and AmF-SnF(2) during the following 7 days. Crevicular samples were collected using filter paper strips and assayed for level of IL-1beta, PGE(2) and VEGF with ELISA test. Data were analyzed with paired and unpaired t test. RESULTS: IL-1beta, VEGF and PGE(2) levels were significantly lower in test compared to control group. Comparing first with second week of treatment, a greater decrease of IL-1beta and VEGF was evident in sample group during the second week. There was a lower decrease of IL-1beta and VEGF during the entire treatment in control group. Differences of PGE(2) levels after 7 days in both the groups were not significant while there was a significant difference during the second week. CONCLUSION: The following data suggest that the use of AmF-SnF(2) could decrease the production of IL-1beta, PGE(2) and VEGF by inflammatory cells.AmF-SnF(2) could be an alternative to CHX mouth rinses in plaque control of patients with implants.

Liposarcoma involving the periodontal tissues. A case report.

Liposarcomas constitute 15 to 20% of all soft tissue tumors. They are extremely rare in the head and neck and in the oral cavity. A 30-year-old patient was seen for a soft, painless mass in the right palate. Through panoramic radiography it was possible to observe a radiolucent area with sharp margins in the right upper quadrant. The lesion, after an incisional biopsy, was diagnosed as a "myxoid liposarcoma." The patient underwent a wide excision of the lesion with bone laminectomy and he is well at a 4-year follow-up. The differential diagnosis included salivary gland tumors and palatal abscess.

Gastric and gingival localization of mucosa-associated lymphoid tissue (MALT) lymphoma. An immunohistochemical, virological and clinical case report.

Non-Hodgkin's lymphomas (NHL) of the mucosa-associated lymphoid tissue (MALT) are characterized by their mucosal and glandular tissue localization. The case described here falls into the European-American classification of a low-grade B-cell lymphoma of the MALT type, with a gingival lesion 2 years after a gastric lesion. The pathogenetic mechanisms of NHL in oral MALT and the diagnosis and treatment are discussed.

Bone-hydroxyapatite interface in retrieved hydroxyapatite-coated titanium implants: a clinical and histologic report.

Two hydroxyapatite-coated implants were retrieved after 12 months of loading because of a fracture of the abutments. The specimens were treated to obtain thin ground sections, and a microprobe chemical analysis was done under a scanning electron microscope equipped with an energy-dispersive x-ray analysis and cathodoluminescence system. Under light microscopy, close contact between the bone and the hydroxyapatite coating was seen, with no gaps at the interface. In some areas of the coating a reduction of the coating thickness could be observed, along with the presence of some detached hydroxyapatite particles embedded in newly formed bone. The chemical analysis of the cathodoluminescent areas at the interface showed a reduced calcium:phosphorus ratio in this region.

Oral ulceration as a presenting sign of unknown sarcoidosis mimicking a tumour: report of 2 cases.

Oral lesions seem to be rather infrequent in sarcoidosis, and only 43 cases have been described in the English literature. Clinically most oral lesions appear as non-tender well-circumscribed swellings or submucosal nodules. Superficial ulceration is unusual. The authors present two cases in which the first presenting symptom of an unknown sarcoidosis was the presence of an oral ulcerated lesion with indurated margins that could easily have been misdiagnosed for a squamous cell carcinoma. It must be stressed that in all ulcerated lesions of the oral cavity, squamous cell carcinoma must always be considered in the differential diagnosis.

Detection of Epstein-Barr virus in oral scrapes in HIV infection, in hairy leukoplakia, and in healthy non-HIV-infected people.

Epstein Barr virus (EBV) has been implicated in the pathogenesis of oral hairy leukoplakia (OHL). EBV is normally detected by lesional biopsy. The objectives of this study were to examine oral scrapes containing squamous epithelial cells (squames) from HIV-infected people with and without clinical lesions of OHL, and from healthy non-HIV-infected controls, for EBV-DNA by the polymerase chain reaction (PCR). EBV-DNA was detected in 65% of HIV-infected people and 20% of healthy HIV-negative controls but in HIV-infected individuals it was found as frequently in those without OHL as in those with. Moreover, EBV-DNA was not detected in all HIV-infected individuals, nor in all OHL. The results suggest that the presence or absence of detectable EBV-DNA in oral scrapes, though a guide, cannot be regarded as absolutely reliable in the diagnosis or exclusion of OHL.

Overexpression of cyclin-D1, bcl-2, and bax proteins, proliferating cell nuclear antigen (PCNA), and DNA-ploidy in squamous cell carcinoma of the oral cavity.

The prognostic role of the expression of bcl-1, bcl-2, bax, PCNA, and DNA-ploidy in a series of 25 oral squamous cell carcinoma (SCC) was investigated. The average age of the patients was 62.04 years (range, 27 to 81 years), with a sex ratio (M/F) of 23:2. The follow-up mean time was 2.24 years (range, 8 months to 8 years from surgery). Immunohistochemistry for PCNA, bcl-2, bcl-1, and bax proteins was carried out on 5-microm serial sections from formalin-fixed, paraffin-embedded tissue. The findings were compared with clinicopathologic data and with follow-up. The statistical evaluation of the results of the current study suggests that the low positivity for PCNA with a high positivity for bcl-2 protein are related to a better clinical behavior of the tumors. By converse, a high expression of PCNA, bax, and bcl-1 appears to correlate with a worse prognosis. All of our cases of SCC showed the presence of aneuploid populations, which was not correlated with the clinicopathologic parameters or with the overexpression of bcl-1, bcl-2, bax, and PCNA. Therefore, the aneuploidy per se did not predict the clinical evolution for the single cases of cancers. Nevertheless, once the parameters considered for the evaluation of DNA were examined in detail, it appeared that some of them, individually or combined with each other or with the expression of bcl-1, bcl-2, and bax, gained statistical significance in predicting the clinical evolution of SCC of our series. Particularly, high values of 2cDI and DNA-MG and the absence or reduction of the euploid population were associated with a short interval between surgery and recurrence or death, and this significance persisted when the simultaneous presence of overexpression of bcl-1 was considered.

Diversity of naturally occurring Epstein-Barr virus revealed by nucleotide sequence polymorphism in hypervariable domains in the BamHI K and N subgenomic regions.

The extent of nucleotide sequence microheterogeneity varies among subgenomic regions of Epstein-Barr virus (EBV). We examined, in EBV-carrying lymphoid cell lines, the extent of polymorphism in EBV DNA fragments amplified from the BamHI E, K, N and Z regions, and then investigated the diversity of the more hypervariable regions in tissues and body fluids. In cell lines, sequence dissimilarities in a genotype-specifying fragment of the EBNA-3C gene varied from < 1-4% within each genotype; dissimilarities in the first intron of the BZLF- 1 gene were < 2% within each genotype. By contrast, dissimilarities in a C-terminal unique domain of the EBNA-1 gene, and in a fragment that encompasses and is upstream of the LMP-1 start codon, varied between 2 and 7% and were not genotype-specific. The sequence diversity in BamHI K and N regions was then examined in tissues and body fluids by single-strand conformation polymorphism (SSCP) analysis and cycle sequencing. Extensive inter-host diversity was observed, whether the host was co-infected by human immunodeficiency virus (HIV) or not. In the oral cavity of HIV-infected patients, inter-compartmental EBV diversity could be demonstrated, even between sites that were anatomically proximate. Studies of BamHI K clones derived from EBV in oral lesions revealed infection by multiple variants. Identification of hypermutable loci within the EBV genome such as those located in the BamHI K and N regions should permit fine discrimination of individual EBV variants.

Benign cementoblastoma associated with an unerupted third molar.

Benign cementoblastoma is a rare lesion representing less than 1% of all odontogenic tumours. It usually affects young people and is located in the posterior jaw. In almost all cases the tumour tends to be associated with an erupted permanent tooth, most often the first molar: only rarely has an association with an impacted or deciduous tooth been reported. The authors present a case of a cementoblastoma involving an impacted third molar.

Human herpes virus 8 (Kaposi's sarcoma herpesvirus).

Human herpes virus 8 (HHV-8) is a recently discovered herpesvirus related to Herpesvirus saimiri and Epstein-Barr virus (EBV). It has been assigned to the Rhadinovirus genus (gamma-2 herpesvirus) on the basis of its genomic sequence and structure. HHV-8 is the first member of this genus known to infect humans and it is now evident that it is the likely cause of Kaposi's sarcoma (KS). The virus is present in endothelial and spindle cells of KS, and in HIV disease the presence of HHV-8 in peripheral blood, and/or serum IgG antibodies to HHV-8, predicts the development of AIDS-related KS. HHV-8 can also infect CD19 + B cells and is of aetiological significance in the development of body cavity B cell lymphomas of AIDS. Of note, the translation products of viral open reading frames (ORFs) reveal HHV-8 to be a molecular pirate, capable of producing homologues of several human gene products that may result in alterations in cell cycle arrest, inhibit apoptosis and cell-mediated immune responses, and thus provide the potential for tumour production.

Immunohistochemical analysis of a dentinogenic ghost cell tumour.

A dentinogenic ghost cell tumour in an 80-year-old male patient is presented. It is an extremely rare tumour and only 10 cases have been reported in the English literature. The lesion showed odontogenic epithelium, ghost cells, dentinoid, giant cells. The immunohistochemical analysis for Mib-1 and bel-2 showed a strong positivity of the cells of the odontogenic epithelium, while with p53 only a rare positivity was observed. Completely negative were the ghost cells, giant cells and dentinoid material. In this tumour the cells expressing Mib-1 and bcl-2 could be the cells that proliferate, and that could undergo malignant transformation.

Paraneoplastic pemphigus: a report of two cases.

Paraneoplastic pemphigus (PNP) seems to be a separate autoimmune mucocutaneous disease. Forty-five cases have been reported. Almost all cases of PNP are associated with a tumour, mostly with haematologic malignancies. Pemphigus-like autoantibodies are detected by direct and by indirect immunofluorescence studies. These autoantibodies appear to be directed against a novel set of autoantigens. Two cases are presented with clinical, histologic, immunofluorescence and immunoprecipitation findings characteristic of PNP.

Human herpesvirus 8 variants in sarcoid tissues.

BACKGROUND: The cause of sarcoidosis is unknown, although mycobacteria have been implicated. We examined sarcoid tissues for human herpesvirus 8 (HHV-8) in addition to mycobacterial genomic sequences. METHODS: Biopsy samples from 17 patients with sarcoidosis were studied (eight transbronchial, 27 lymph node, two skin, and two oral mucosa). We used tissues (n = 137) from 96 patients without sarcoidosis as negative controls. A nested PCR was applied to amplify a segment of open reading frame (ORF) 26 of the HHV-8 genome, and a heminested PCR was to amplify a segment of ORF 25 of HHV-8 and of the 16 S rRNA gene of mycobacteria. Differences in base sequences of the amplified fragments were resolved with single-strand conformation polymorphism and dideoxy sequencing. FINDINGS: HHV-8 ORF 26 DNA was detected in significantly higher proportions of sarcoid than of non-sarcoid tissue samples from lung (8/8 vs 0/54; p < 0.0001), lymph nodes (26/27 vs 6/29; p < 0.0001), skin (2/2 vs 0/17; p = 0.006), and oral tissues (2/2 vs 1/13; p = 0.029). 31 (82%) of the 38 ORF 26 DNA-positive sarcoid specimens were also positive for ORF 25 DNA. For mycobacteria-like 16 S rRNA DNA, the proportion positive was significantly higher in sarcoid than non-sarcoid tissues for lymph node samples (11/27 vs 2/29; p = 0.003) but not for other tissues (lung 3/8 vs 22/54; skin 2/2 vs 15/17; and oral tissues 1/2 vs 0/13). Overall, the prevalence of HHV-8 ORF 26 sequences was higher in sarcoid tissues than in non-sarcoid tissues (p < 0.0001). When patients whose tissues were included in a masked phase of the study were treated as units of analysis, eight of eight sarcoidosis patients were positive for HHV-8 ORF 26 DNA, compared with three of 56 control patients (p < 0.0001); for mycobacteria-like sequences, three of eight sarcoidosis patients were positive, compared with four of 56 controls (p = 0.0464). The HHV-8 ORF 26 sequences, ten of which were unique, could be segregated into four groups according to peptide motifs. In seven of nine patients from whom biopsy samples were taken from various sites, different sequences were recovered. The mycobacterial sequences amplified from sarcoid tissues were also varied, but none was homologous to those of known species. INTERPRETATION: Variant HHV-8 DNA sequences are found in a wide range of sarcoid but not non-sarcoid tissues. Mycobacteria-like 16 S rRNA sequences are more frequently present in sarcoid lymph nodes and not in other tissue types, but do not indicate infection by a particular mycobacterial species.

Histological and histochemical analyses of acid and alkaline phosphatases around hydroxyapatite-coated implants: a time course study in rabbit.

One of the concerns pertaining to hydroxyapatite (HA)-coated dental implants is their possible dissolution over time, with ultimate loss of the implant. HA-coated dental implants were inserted medially into rabbit femoral articular knee joints. The implants were retrieved after 1 week, 1 month, 3 months and 6 months. At 1 week, many alkaline phosphatase (ALP)-positive osteoblasts were observed near the implant surface. No signs of degradation of the coating were present. At 1 month, only few ALP-positive osteoblasts were present in the marrow spaces at the interface with the coating. Many acid phosphatase (ACP)-positive cells were observed near the coating. In many marrow spaces the HA coating was reduced in thickness. At 3 months, a further reduction of the thickness of the coating, in the areas in contact with marrow spaces, was seen. Many ACP-positive cells were present in tight contact with the coating. Few ALP-positive osteoblasts were present. At 6 months, in many areas in contact with marrow spaces, the HA coating was completely resorbed. The histological and histochemical results seem to point to the existence of two types of ACP-positive cells: multinuclear, often in the process of phagocytosing HA particles, and mononuclear, with a morphology similar to osteoclasts.