new-true-dentalloy and indiloy

The release of mercury vapor was determined from eleven different amalgams exposed to externally induced corrosion by galvanic contact with a dental casting gold alloy. The electrolyte was an artificial saliva solution at 37 degrees C. The corrosion rates of the amalgams could be divided into two groups corresponding to the grouping into conventional and high-copper materials. The mercury release rate decreased during the 24 h test period for all the amalgams except one containing indium. There was no significant difference in the total mercury release between the conventional and high-copper amalgams as groups. The same applied for the individual products, except the one containing indium, which released significantly more mercury vapor than the two products with the lowest release.

Topics: Analysis of Variance; Copper; Corrosion; Dental Alloys; Dental Amalgam; Electrogalvanism, Intraoral; Gold Alloys; Indium; Mercury; Silver; Statistics, Nonparametric

The purpose of this study was to evaluate survival predictions made for four different amalgam alloy restorations, using a mixture model involving the standard Weibull function. The amalgam alloys were placed by students and staff in patients attending a dental hospital, and 1680 restorations were examined over periods of up to 18 years. Based on maximum likelihood estimations of the parameters of the mixture model distribution, predictive survival distributions were generated and found to match closely the actuarial survival estimates established from the same data. The 13-year restoration survivals of one low-copper alloy could be predicted accurately from the 6-year survival results. However, another low-copper alloy and two high-copper alloys with much lower restoration failure rates required 18 years of data for accurate long-term survival predictions.

Topics: Actuarial Analysis; Copper; Dental Alloys; Dental Amalgam; Dental Restoration, Permanent; Equipment Failure; Humans; Materials Testing; Probability; South Australia; Time Factors

Topics: Acrylic Resins; Bisphenol A-Glycidyl Methacrylate; Composite Resins; Dental Alloys; Dental Amalgam; Dental Plaque; Dentures; Dietary Carbohydrates; Glass Ionomer Cements; Humans; Polyurethanes; Random Allocation; Research Design; Surface Properties