Research Outputs (Oral Health Sciences)

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Author: search.filters.author.Grossman, E. S.Start date: 1984

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Now showing 1 - 10 of 21
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    Cemento-enamel junction variability within the mouth
    (1988) Grossman, E. S.; Hargreaves, J. A.
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    Seal development and composition at amalgam-ceramic interfaces after NaCl and Na2S storage
    (1987) Jodaikin, A.; Grossman, E. S.; Witcomb, M. J.
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    Base solubility and marginal sealing in amalgam restored teeth
    (1991) Grossman, E. S.; Witcomb, M. J.; Matejka, J. M.
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    Marginal adaptation in composite resin restored dentine cavities Showing gross marginal leakage
    (1986) Grossman, E. S.; Sparrius, O.
    The aim of bonding composite resin restorations to the tooth is to ensure retention and also to prevent marginal leakage at the tooth restoration interface, a process which can lead to further caries. An in vitro marginal leakage study' of composite resins in combination wTEh acid' etching and dentine and enamel bonding agents highlighted the lower sealing potential of both enamel and dentine bonding agents to dentine (36%>seal) compared to enamel (79%>seal). Several studies 2-4 suggest that if the inner surface of the resin restoration appears as a well replicated negative impression of the adjacent tooth surface, bonding has been achieved. This study was undertaken to examine the appearance of the inner surface of resin restorations which showed gross marginal leakage in restored dentine cavities to determine the degree of marginal adaptation between the restoration and cavity surface.
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    Analyses of marginal seals in aged amalgam restorations using extraction replicas
    (1984) Grossman, E. S.; Witcomb, M. J.; Jodaikin, A
    Since dental amalgam does not bond chemically to tooth structure, a microcrevice is present at the amalgam/tooth interface of a freshly placed restoration. This gap is of sufficient width to allow fluids and microorganisms to pass along the cavity walls and thereby facilitating the recurrence of dental caries, which accounts for the majority of amalgam restoration replacements.
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    The effect of enamel etchants and a cleaning agent on cut dentine: an in vitro study
    (1985) Sparrius, O.; Grossman, E. S.
    Cavities 1,25 x 2,00mm were prepared in the cervical dentine of extracted human premolar teeth using a no. 577 tungsten carbide bur. The cavity depth was standardised at 1mm with the aid of a depth gauge fitted to the high speed airturbine. The cavities were hemisected with a low speed, water cooled, diamond disc saw, then cleaned with water and air. Thereafter the following solutions were applied to six cavities each as per manufacturers' instructions: Anhydron; Chemfill (Citric Acid); Enamelbond etchant and Scotchbond etchant gel. Once the cavities had been cleaned and dried, the specimens were prepared for scanning electron microscopy (SEM) and viewed at magnifications of x35, x200 and x2000. Cavity walls and floors were viewed separately and representative areas photographed. Similarly prepared unetched cavities served as a control.
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    Primary fixation of vervet monkey oral epithelium for SEM and TEM
    (1987) Grossman, E. S.
    Vervet monkey attached gingiva and alveolar mucosa was used to investigate the effect of primary fixative composition and osmolarity on the scanning electron microscope appearance and epithelial cell surface feature density. Primary fixation was obtained using 12 different fixatives with osmolarities varying between 320-2010mOsm followed by further standard SEM processing procedures. All primary fixatives investigated produced acceptably fixed oral epithelium for SEM study, showing all the morphologic features characteristic of either keratinized or non-keratinized oral tissue. Point counting revealed that the density of microvilli of attached gingiva epithelial cells when fixed at 2010mOsm was 72 +/- 8% of the cell surface area. This decreased to 40 +/- 5% when fixed at 320mOsm. Similarly the microplication density of the alveolar mucosa epithelial cells decreased from 70 +/- 5% at 2010mOsm to 43 +/- 7% at 320mOsm. Both these differences proved to be highly significant
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    Experimental marginal leakage around dental amalgams placed in artificial cavities
    (1984) Jodaikin, A.; Grossman, E. S.
    Experimental marginal leakage of high- and low-Cu amalgam restorations placed in acrylic teeth, where the cavities were untreated or painted with denatured collagen and/or a CaP slurry, was assessed after specimens were stored in a 1% NaCl solution for ten days and for one yr. All specimens stored for ten days showed severe marginal leakage. High- and low-Cu amalgam restorations placed in untreated acrylic teeth cavities formed seals after a storage period of one yr, indicating that these materials are able to form a seal without interacting with a natural tooth cavity interface. Cavities treated with denatured collagen also formed seals in the long-term group. It was apparent that, when the CaP slurry was used, generally more leakage resulted after the year's storage period than when amalgam restorations were placed in uncoated acrylic cavity surfaces or in those painted with denatured collagen.
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    Effect of amalgam type on artificial caries
    (1994) Grossman, E. S.; Matejka, J. M.
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    How well do fourth year Wits Dental Students place resin composite restorations?
    (2003) Lightfoot, J.; Clarke, F. M.; Grossman, E. S.
    OBJECTIVES:To evaluate, by means of a scanning electron microscope (SEM) the quality of resin composite restorations, placed as a first attempt by fourth-year dental students. METHODS: Ten Class IV direct composite restorations, placed in plaster-mounted extracted incisor teeth as part of pre-clinical course requirements, were selected. Specimens were evaluated and graded on a two-point scale by a staff member according to departmental clinical evaluation criteria. Five restored teeth were prepared for surface evaluation of marginal integrity, surface roughness and contour using SEM. The remaining specimens were embedded in resin and ground down transversely, parallel to the incisal edge until a dentine core was apparent. The ground surfaces were polished, prepared for SEM and assessed for etched layer, placement of bonding agent, composite adaptation and overall consistency. RESULTS: Clinical assessment and SEM surface evaluation correlated favourably for all criteria, except contour, indicating that students were reasonably competent in finishing techniques. Ground samples revealed acceptable etched enamel layers and marginal adaptation. Bonding agent thickness varied between 0 and 200 microns casting doubt on procedural accuracy. Porosities and voids were apparent within the resin composite. Internal features were the main reason for unsatisfactory grades. CONCLUSIONS: Students placed restoration satisfactorily. They would benefit if able to examine sectioned restorations to understand critical placement techniques which would contribute to resin composite restoration success. A research component can be introduced into the dental undergraduate curriculum by way of similar projects linked to didactic course-work.