Panoramic radiograph as a method for detecting calcified atheroma plaques. Review of literature

Cerebrovascular accident (CVA) is the third cause of death in industrialized countries, following cardiovascular disease and cancer. It is therefore a significant public health issue, not only due to its high incidence, but also to the high costs involved in the physical and psychological rehabilitation of these patients. Dental Practitioners, as health care providers, ought to play their part in this issue and contribute, within their means, to the early detection of patients at risk of having a CVA. Since the eighties, different authors have described the possibility of detecting calcified atheroma plaques located at carotid artery bifurcation through panoramic radiograph. In this way, the Dental Practitioner s possibilities in this field have been extended. However, this new use of panoramic radiograph must overcome certain obstacles before it is implemented as a new screening method for patients at risk of having a CVA. Amongst these, we would have, on the one hand, the assessment of the real clinical significance, as regards prognosis, of atheroma plaque calcification as well as its usefulness as a factor for predicting the appearance of CVA symptoms and, on the other hand, the possibility of making a correct differential diagnosis regarding other calcified structures that may appear on panoramic radiograph.     

Electron microscopic observations of "keratin pools" in chronic hyperplastic oral mucosa.

"Keratin pools," previously characterized clinically and histochemically in the superficial epithelium of chronic hyperplastic oral mucosa, were studied by light and electron microscopy. These occured as small beaded and larger coalescent masses which varied in metachromasia. Ultrastructurally, the "keratin pools" consisted of electron-dense, amorphous or finely-granular material developing and coalescing, chiefly as extracellular deposits. The "pools" frequently possessed a layered arrangement alternating with cells having distinct tonofilaments, desmosomes, and definite cell membranes. Occasional bands of filamentous-like material, possibly representing tonofilament bundles, were observed in some "pools."     

Fracture process characterization of fiber-reinforced dental composites evaluated by optical coherence tomography, SEM and optical microscopy

This study used optical coherence tomography (OCT) compared to scanning electron microscopy (SEM) and optical microscopy (OM) to evaluate qualitatively crack propagation and final fracture in restorative composite materials - Filtek Z250 and Filtek Z350 (3M ESPE) - with fiber reinforcement after cyclic loading. Samples were made using a split mold. Initially, 3-point bending tests were performed to determine the maximum force and tension at the fracture moment using samples without fiber reinforcement. Then, mechanical cycling tests were performed using samples with glass fiber embedded internally. The failures were analyzed using the 3 methods described before. OCT permitted good characterization of internal crack propagation of the dental composites, which, however, could not be visualized by either SEM or OM. OCT was proven to be laboratory research tool that is easy to use, does not require any specific preparation of the samples, and is less expensive than SEM.     

Dietary influences on the formation of dental calculus in rats

Eleven diets were evaluated for their ability to produce dental calculus in albino rats. A diet containing 50 % cornstarch, 32 % nonfat dry milk, 3 % liver powder, 5 % celluflour, 1 % cottonseed oil, 5 % powdered sucrose, 1 % calcium chloride dihydrate, 2.7 % sodium dihydrogen phosphate monohydrate, and 0.3 % magnesium sulfate (Francis and Briner 1969) was remarkably effective. On the basis of a 0–3 calculus scoring system, an average score of 2.36 (S.D. = 0.65) resulted after 4 weeks' exposure to the above diet and, after 8 weeks, the average score was 2.59 (S.D. = 0.56).
While it was found that, in general, high cornstarch and milk powder diets were associated with higher calculus scores, no other diet remotely approached the above diet in calculogenicity.     

Matrix metalloproteinase-8 (MMP-8) in pulpal and periapical inflammation and periapical root-canal exudates

AIM: To study the presence, levels and molecular forms of matrix metalloproteinase (MMP) -8 (collage-nase-2) in pulpal and periapical inflammation, and the changes in MMP-8 levels in root-canal exudates during root-canal treatment. METHODOLOGY: Periapical exudate samples were collected from 11 necrotic teeth with radiographically verified periapical periodontitis during three root-canal treatment visits with interappointment calcium hydroxide (Ca(OH)2) medication. MMP-8 levels and molecular forms were analyzed with immunofluorescent assay (IFMA) and Western immunoblot. Inflamed pulp tissue and periapical granuloma tissue (n = 10 for both) were obtained from other patients and used for MMP-8 immunohistochemical (IHC) staining. RESULTS: The periapical exudate samples demonstrated marked differences in MMP-8 levels between the teeth in the first visit and significant decrease in MMP-8 levels during the root-canal treatment (P = 0.0107). One specimen failed to show a decrease in MMP-8 below 1000 ng mL(-1) a vertical root fracture was later diagnosed and the tooth extracted. IHC staining showed that in addition to PMN-leucocytes, macrophages and plasma cells produced MMP-8 in pulp and periapical granulomas. CONCLUSIONS: The findings demonstrate the presence of MMP-8 in the inflamed pulp and periapical tissue, indicating that MMP-8 has a role in pulpal and periapical inflammation, most likely participating in tissue extracellular matrix degradation. They further indicate that MMP analysis from periapical exudate could be used to indicate and monitor inflammatory activity and the success of treatment in teeth with periapical lesions.     

Diffuse but unilateral gingival enlargement associated with von Recklinghausen neurofibromatosis: a case report

BACKGROUND: An 8-year old girl was referred for diagnosis and treatment to the Department of Periodontology Oral Surgery of the University Hospital of Liège with an unusual clinical situation: a major, non-inflammatory, diffuse but unilateral enlargement of the interproximal, marginal and attached gingiva around all teeth of the right side of both the upper maxilla and mandible, whereas the alveolar process of the left side of upper and lower arches appeared strictly normal. METHOD: The clinical examination showed delayed eruption of some permanent teeth in the 1st and 4th quadrants. Except for its asymmetric occurrence, this gingival enlargement strongly resembled phenytoin-induced enlargement or gingival fibromatosis. This unilateral expression was evocative of a vascular or neurologic pathology. Several large "café-au-lait" spots were found disseminated on the body. Several selective surgical removals of thick gingival caps impairing the eruption of some permanent teeth were performed, and the removed tissues were histologically analyzed. RESULTS: Because of the presence of the large "café-au-lait" spots, a clinical diagnosis of Von Recklinghausen's disease was given and later confirmed several times by the histological analysis of the gingival biopsies. Now, 6 years later, this gingival enlargement due to the development of intra-gingival neurofibromas is stable and all permanent teeth have had a normal eruption, but alveolar bone growth has been partly impaired by the presence of the tumor. CONCLUSIONS: The present case of unilateral diffuse hyperplasia is a unique clinical expression of neurofibromatosis type I, a slowly evolving neurodermic dysplasia.     

Immediate loading of modular transitional implants: a histologic and histomorphometric study in dogs

Modular Transitional Implants (MTI) are made from pure titanium and are used to support fixed provisional restorations during the osseointegration of definitive implants. This study histologically examined the jaw response to loaded MTIs in the dog mandible. Three implants were inserted transmucosally into each side of the mandible in 3 dogs. Stability was examined using a Periotest. Anterior and posterior implants were splinted using a cemented acrylic resin fixed partial denture to allow immediate loading. The middle implant remained unloaded and was used as a control. Dogs were sacrificed 11 to 12 weeks after implantation, and tissue blocks containing the implants were removed. Histologic examination showed that 10 of the 18 implants had good bone-to-implant contact, with the percentage of bone contacting the threaded portion of the implant varying from 30% to 65%. There was no statistical difference (p > 0.1) in percentage of bone-to-metal contact between loaded and unloaded implants. Six implants were entirely surrounded by connective tissue with or without inflammation; two implants were lost during the study. The success rate did not differ between loaded and unloaded implants. In the successful implants trabecular bone made good contact with the implant, forming supporting struts. There was bone remodeling in some bone-to-metal contact areas. It is believed that success was mainly influenced by the initial bone density at the implant site and by the uncontrolled load that the animals applied to the implants during the early healing stage.