Effect of low-level laser irradiation on osteoblast proliferation and bone formation.

Applications of laser therapy in biostimulation and healing injured tissues are widely described in medical literature. The present study focuses on the effects of laser irradiation on the growth rate and differentiation of human osteoblast-like cells seeded on titanium or zirconia surfaces. Cells were laser irradiated with low therapeutical doses at different intervals and the effects of irradiation were evaluated at each time-point. After 3 hours lasered cells showed an enhanced mitogen activity compared to non-lasered control cells and a higher alkaline phosphatase activity, marker of bone formation. At the same time, the mRNA of RUNX2 and OSTERIX, two genes involved in osteoblast differentiation, showed a clear decrease in lasered cells. This reached the lowest value 6 to 12 hours after irradiation, after which the transcripts started to increase, indicating that the laser treatment did promote the osteogenic potential of growth-induced cells. These results indicate that Low Level Laser Treatment (LLLT) stimulates osteogenic cell proliferation.

Dental hygienists behaviour towards HIV-positive patients in highly active antiretroviral therapy era: a pilot survey.

OBJECTIVES: Literature reports highlighted the presence of discriminatory episodes towards individuals infected with human immunodeficiency virus (HIV) on behalf of dental care workers. The purpose of this study was to assess hygienists' attitude when treating HIV-infected individuals in the era of highly active antiretroviral therapy (HAART). METHODS: A national observational study was carried out on all the members of an Italian hygienist association. An anonymous questionnaire was mailed to 1247 hygienists: the questionnaire investigated demographic data, the relationship between the hygienists and HIV-infected persons, to identify the presence of discriminatory behaviour, the hygienists' scientific knowledge of HIV-related problems and the precautions normally used in the office to prevent cross-infections. RESULTS: Of the 1247 questionnaires that were delivered to hygienists, 287 (23%) were completed and returned within a 6-month period. A total of 287 hygienists answered the question 'Did you ever deny treatment to an HIV-infected persons?' and 17 hygienists (5.9%) replied 'Yes'. Protective eyewear [odds ratio (OR), 0.036; 95% confidence interval (CI), 0.002-0.818; P = 0.037] and public practice [OR, 2.93; 95% CI, 0.97-8.87; P = 0.057] were associated with refusing to treat HIV-infected persons. CONCLUSION: Our findings highlight the existence of episodes of discrimination by some hygienists towards HIV-infected individuals. From clinical point of view, this discriminatory behaviour may expose the dental health care workers and their patients to a greater risk of cross-infection.

Chondroma of the tongue.

Chondroma is a remarkably rare lesion of the oral soft tissues. Most previously reported chondromas of this area have been associated with varying percentages of fibrous, adipose or bone tissues, and the occurrence of such neoplasms exclusively composed of chondromatous tissue is exceedingly rare. We report the clinicopathological features of a pure chondroma of the dorsum of the tongue, occurring in a 51-year-old woman and discuss the possible origin of the tumour.

Traumatic ulcerative granuloma with stromal eosinophilia of the oral mucosa: histological and immunohistochemical analysis of three cases.

Traumatic ulcerative granuloma with stromal eosinophilia is an ulcerated oral lesion which pathogenesis is still unclear. Clinically, this disease is characterized by the presence of chronic ulcerative lesions with elevated and indurated borders in the oral mucosa. It usually develops rapidly and persists for several weeks or months, it presents mainly on the tongue but other areas such as gingival, cheek and vestibular mucosa may also be involved. We report three cases showing their clinical, histological and immunohistochemical analysis. In this study the authors underline the importance of a correct differential diagnosis and monitoring of these patients in order to prevent the development of possible serious complications.

Odontoma: retrospective study and confocal laser scanning microscope analysis of 52 cases.

AIM: The aim of this study was to perform a retrospective analysis of 52 cases of odontoma treated at the Department of Dentistry and Surgery, University of Bari, in the period 1971-2005. METHODS: The odontogenic tumors were diagnosed as complex or compound odontoma following histological analysis and clinical radiological examination, and applying the 2005 WHO classification. The data analysis was conducted by considering the following factors: gender, age, site of the lesion, association with impacted teeth, aplasia, presence of supernumerary teeth as well as preoperative diagnosis by panoramic and periapical radiographs. Biopsy tissue samples were conventionally processed for histopathologic paraffin embedding and then were observed by optical microscopy and subsequently by confocal laser scanning microscopy (CLSM) in autofluorescence. RESULTS: Thirty specimens (57.6%) were from females and 22 (42.3%) were from males patients. The patients' age ranged from 5 to 75 years. Fifty-one percent of the specimens were excised from the mandible. In the maxilla, the most common location for odontomas was the anterior region. Most odontomas were associated with impacted teeth and only in one case there was an odontoma instead of a permanent tooth. CONCLUSION: Odontomas are considered hamartomatous malformations whose diagnosis is generally formulated by routinary radiographic examination. The CLSM analysis could help in diagnosis and histopathological analysis showing well-defined follicular area entrapped in hard tissues and pointing out ghost cells, otherwise not identifiable by traditional microscopy.

Complex odontoma: confocal laser scanning microscopy analysis of a case.

Confocal laser scanning microscopy (CLSM) represents a recent acquisition in the study of biological samples stained for fluorescence observation. Particularly, this technique allows a bidimensional investigation of tissues and cells with the possibility to elaborate a three-dimensional model. The aim of this study is the use of this technique, as a complementary and not substitutive application of the histological examination, for the morphological and histopathological analysis in a case of mixed complex-composed odontoma. The analyzed specimen has been surgically removed in the superior frontal region in a 12 year-old boy and submitted to conventional histopathological analysis. The specimen, hematoxylin-eosin stained, has been subsequently submitted to confocal laser scanning microscopic analysis in autofluorescence by using a Nikons C1 system. This analysis has underlined not visible aspects in traditional optical microscopy, such as the mineralization of hard tissues and the morpho-structural organization of the cellular component. The presence of enamel and dentin may be observed in the different phases of odontogenesis with clear fluorescence gradients determined by the different mineralization degrees. Thus, the odontogenetic components appear strongly autofluorescent in the classical follicular configuration. Three-dimensional reconstruction is made possible by the acquisition of serial bidimensional images that are subsequently analysed by using a specific software device. This study shows the confocal laser scanning microscopy versatility in the analysis of odontogenic neoplasms with production of mineralized tissues.

Multiple and giant mandibular osteomas in a Gardner's syndrome. Case report.

Though rare, Gardner's syndrome is a systemic disease with frequent jawbones involvement. Dento-maxillo-facial lesions both in early and in advanced stages should be known by dentists and other specialists. In fact, these lesions should be sought in patients with intestinal polyposis, while they could be the first sign of Gardner's syndrome not yet diagnosed.

Clinical management and microscopic characterisation of fatigue-induced failure of a dental implant. Case report.

BACKGROUND: Osseointegrated endosseous implants are widely used for the rehabilitation of completely and partially edentulous patients, being the final prosthodontic treatment more predictable and the failures extremely infrequent. A case of fracture of an endosseous dental implant, replacing the maxillary first molar, occurring in a middle-age woman, 5 years after placement is reported. MATERIALS AND METHODS: The difficult management of this rare complication of implant dentistry together with the following rehabilitation is described. Additionally, the authors performed an accurate analysis of the removed fractured implant both by the stereomicroscope and by the confocal laser scanning microscope. RESULTS AND DISCUSSION: The fractured implant showed the typical signs of a fatigue-induced fracture in the coronal portion of the implant together with numerous micro-fractures in the apical one. Three dimensional imaging performed by confocal laser scanning microscope led easily to a diagnosis of "fatigue fracture" of the implant. The biomechanical mechanism of implant fractures when overstress of the implant components due to bending overload is discussed. CONCLUSION: When a fatigue-induced fracture of an dental implant occurs in presence of bending overload, the whole implant suffers a deformation that is confirmed by the alterations (micro-fractures) of the implant observable also in the osseointegrated portion that is easily appraisable by the use of stereomicroscope and confocal laser scanning microscope without preparation of the sample.

Multiple parotid lymphoepithelial cysts in patients with HIV-infection: report of two cases.

OBJECTIVE: Bilateral and multiple lymphoepithelial cysts (LECs) of major salivary glands, in particular of parotid glands, are quite rare and have been reported in human immunodeficiency virus (HIV) infected patients with an incidence of about 3-6%. These lesions represent an early manifestation of HIV infection and are rarely found in patients with advanced acquired immunodeficiency syndrome. MATERIALS: Two cases of parotid LECs, the first occurring in a middle-age white woman and the second in a young white boy, both in advanced phases of HIV infection, are reported. RESULTS: Clinical, cytological, histological and immunohistochemical (cytokeratin AE1/AE3, CD20, CD45RA, CD8, kappa and lambda immunoglobulin light chains, S-100, MLA and Ki67) features are described. CONCLUSIONS: Fine needle aspiration (FNA), a relatively non-traumatic procedure, could represent both a diagnostic and a therapeutic tool in parotid LECs. No surgical therapy is usually required for these lesions and aspiration of cystic fluid with FNA is quite resolutive, although evidence of further relapses does exist. Surgical excision may become necessary when pain, because of persistent and progressive swelling of the parotid gland, occurs.