RESUMO
Due to aging and gingival recession, the radicular structures are exposed to cariogenic attacks from the oral cavity. This phenomenon leads to a constantly higher frequency of root caries. The aspect of these carious lesions was analysed by a histological and an SEM study. To conclude the study, a clinical description of the lesions and an epidemiological survey were realized on 112 patients for 16 months.
Assuntos
Cárie Dentária/patologia , Raiz Dentária/ultraestrutura , Adulto , Resinas Compostas , Cárie Dentária/etiologia , Dentina/ultraestrutura , Feminino , Retração Gengival/complicações , Cimentos de Ionômeros de Vidro , Humanos , Masculino , Pessoa de Meia-Idade , Raiz Dentária/patologiaRESUMO
Following a recall of the various preparations of the cavo-surface for posterior composites (straight, rounded, concave bevel, or without bevel), a study at the M.E.B. analysed the interface between the tooth and the filling in each case investigated. With the straight bevel with a slight angulation (40 degrees), the limit of the cavity-filling joint is clear. A disintegration of the material exists with the straight bevel having a 70 degrees angulation. The hiatus is even more marked with rounded or concave bevels. The absence of a bevel provides a clear occlusal joint without irregularity at the cavo-surface limit. In the light of this investigation and the results observed in the clinic in the medium and long term, it appears that the preparation of the cavo-surface margins of occlusal cavities of the pre-molars and molars for posterior composites may make do with a bevel which is not very extensive and not widely opened (40 degrees), or even the total absence of a bevel.
Assuntos
Colagem Dentária , Preparo da Cavidade Dentária/métodos , Dente Pré-Molar , Resinas Compostas , Esmalte Dentário , Humanos , Dente Molar , Propriedades de SuperfícieRESUMO
Some of various iatrogenic diseases, during manual endodontic treatments, are analysed, from detailed clinical instances. Discussion leads to insist upon some classical and original ways of prevention. From general point of view, it is unavoidable to realize with gentleness, never forcing, endodontic proceedings. Deep perception of internal dental morphology is quite necessary and must be respected during treatment. Besides, histo-pathological modifications of parietal dentine have to be known, not only from intellectual but also from tactile point of view. Each practitioner will progressively improve.
Assuntos
Cavidade Pulpar/lesões , Doença Iatrogênica , Tratamento do Canal Radicular/efeitos adversos , Instrumentos Odontológicos/efeitos adversos , Corpos Estranhos , HumanosRESUMO
Preparation of the cavo-surface margin for fillings with "composites resins" is an important operative step. The good peripheral fit of the restoration and the stability of the bond between tooth and material depend on that preparation. How should the "bevel" be shaped? Scan electron microscopy of long bevels and rounded bevels show that the former seem more favorable to the fit of the filling. The section of enamel prisms is clean. The aprismatic surface area disappears. This enables to etch the cristallites in a more favorable axis as opposed to the rounded bevel.
Assuntos
Resinas Compostas , Colagem Dentária , Preparo da Cavidade Dentária , Esmalte Dentário/ultraestrutura , Infiltração Dentária/prevenção & controle , Humanos , Microscopia Eletrônica de Varredura , Dente Molar , Propriedades de SuperfícieRESUMO
The porosity and the leakage properties of 13 temporary fillings used between each appointment during endodontic treatment were investigated by means of thermocycling and dye staining of the interface between the teeth and the filling material. A scanning electron microscope was also used for these observations. The 8 commercially produced temporary fillings seal adequately the cavity whereas the 5 materials prepared and mixed by the practitioner allowed wide staining diffusion and therefore were leaky.