Effect of surface treatment on the corrodibility of dental amalgam

A potentiostatic study of the corrosion behavior of anodized and nonanodized aluminum alloy

The clinical implication of this study is that some improvement in the corrosion resistance of denture bases made with aluminum alloy D-214 may be obtained by anodization. However, since this study does not exactly duplicate an oral environment or take into consideration the variation in oral environments, it cannot be assumed that the additional corrosion resistance would be discernible in a particular patient.

Effect of clinical finishing procedures on amalgam microstructure

Spherical amalgam specimens were burnished, burnished-polished, polished (wet), or polished (dry). The amalgams were sectioned normal to the prepared surface, elemental analyses were made at a series of depths from the surface with the electron microprobe and the phase fractions were calculated. Significant variations in phase distributions exist within 100 micrometers of the surface.

Potential sweep and intensiostatic pulse studies of Sn, Sn8Hg and dental amalgam in chloride solution

The anodic behavior of the Sn, the Sn8Hg (gamma2) phase and the dental amalgam in a chloride solution has been investigated by means of the linear potential sweep and of the intensiostatic pulse method. The results indicate that anodic current varies with chloride concentration and that dissolution occurs prior to passivation of the electrode. The anodic charge needed for the passivation is smallest for the dental amalgam.

Effects of burnishing on microleakage in an amalgam system

No significant increase or decrease in microleakage occurred as a result of single or double burnishing of amalgam. When cavity varnish use was compared with no use of cavity varnish, significantly less microleakage was noted with the nonburnished control, single-burnish, and double-burnish techniques utilizing the cavity varnish. It was concluded that burnishing is not a factor in microleakage when using Optaloy, but microleakage can be reduced by the use of a cavity liner such as Copalite.

Microscopic observations of amalgams carved by different methods and subsequently polished

Occlusal amalgam restorations placed in extracted deciduous molars were studied using an electron microscope. The fillings were carved only or both carved and burnished, and all were subsequently polished. Observations were made before and after polishing, and the results emphasized the effects of carving, burnishing, and polishing on the surface texture and marginal integrity of amalgam fillings.

The effect of finishing on the anodic polarization of high-copper amalgams

The influence of surface finishing procedures on the corrodibility of high-copper amalgams was measured. Anodic polarization curves were determined in Ringer's solution for amalgam samples made from a dispersion and a ternary alloy. Three types of finishes were compared: as carved, burnished, and polished. The polarization curves of the burnished and polished specimens were statistically similar (P greater than 0.05) at all potentials investigated. The carved samples exhibited higher corrosion currents at most of the potentials investigated.

The effect of surface finish on the anodic polarization of a conventional spherical amalgam

The corrosion of carved, burnished, polished, and burnished--polished samples of a conventional spherical amalgam was studied by anodic polarization in Ringer's solution. The effect of the variation of the mercury content from 40 to 60 wt% on the corrosion of burnished or polished samples was also investigated. It was found that burnished and burnished--polished samples corrode the least and carved samples the most. The current-density peak associated with gamma2 was of greater magnitude in polished specimens than in burnished specimens throughout the range of mercury concentrations investigated. It is hypothesized that lower porosity and more ready passivation of the surface due to a high amount of gamma2 are the reasons that burnished samples corroded less than polished samples in this anodic polarization test.