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G E Stoner

Publications and source records attributed to G E Stoner.

15 recordsLinked to original sources

Electrochemical characteristics of the S.I.A. dental amalgam cavity liner.

Selective interfacial amalgamation (S.I.A.) has been developed as a dental amalgam cavity liner with the intent of increasing the restoration-tooth adhesion and reducing the debilitating effects of corrosion and marginal leakage. This paper examines the S.I.A. liner's effectiveness as a corrosion preventive cavity liner by two experimental techniques: anodic polarization and differential aeration tests. The results from these tests indicate that S.I.A. does enhance the corrosion resistance of a dental amalgam.

Corrosion

Dental amalgam stabilization by selective interfacial amalgamation.

The purpose of this investigation was to explore the feasibility of enhancing the electrochemical stability of dental amalgam restorations by a process of "selective interfacial amalgamation." If dental amalgam restorations can be selectively alloyed at the tooth-amalgam interface, to a minor thickness as compared with the dimensions of the bulk amalgam, so as to present a more electrochemically stable phase than psi2 to the oral environment, corrosion will be reduced and desirable qualities of existing amalgams can be utilized. It was found that selective interfacial amalgamation was indeed possible and that it could be readily accomplished using a silver suspension as a cavity liner. By then placing a conventional silver-tin amalgam according to ordinary dental techniques, mercury expressed during hand condensing reacted with the silver in the liner resulting in the formation of an integral amalgam restoration with the more noble psi1 phase adjacent to tooth structure. In vitro corrosion tests of samples so prepared exhibited corrosion resistance far superior to unlined control samples.

Corrosion

Microbial detection method based on sensing molecular hydrogen.

A simple method for detecting bacteria, based on the time of hydrogen evolution, was developed and tested against various members of the Enterobacteriaceae group. The test system consisted of (i) two electrodes, platinum and a reference electrode, (ii) a buffer amplifier, and (iii) a strip-chart recorder. Hydrogen evolution was measured by an increase in voltage in the negative (cathodic) direction and recorded on a strip-chart recorder. Hydrogen response curves consisted of (i) a lag period, (ii) a period of rapid buildup in potential due to hydrogen, and (iii) a period of decline in potential. A linear relationship was established between inoculum size and the time hydrogen was detected (lag period). Lag times ranged from 1 h for 10(6) cells/ml to 7 h for 10(0) cells/ml. For each 10-fold decrease in inoculum, length of the lag period increased 60 to 70 min. Mean cell concentrations at the time of hydrogen evolution were 10(6)/ml. Based on the linear relationship between inoculum size and lag period, these results indicate the potential application of the hydrogen-sensing method for rapidly detecting coliforms and other gas-producing microorganisms in a variety of clinical, food, and other samples.

Bacteriological Techniques