DIN Standards Committee Dentistry
DIN EN ISO 13078-2
Dentistry - Dental furnace - Part 2: Test method for evaluation of furnace programme via firing glaze (ISO 13078-2:2016); German version EN ISO 13078-2:2016
Zahnheilkunde - Brennofen - Teil 2: Prüfverfahren zur Bewertung des Brennprogrammes mittels Brenngradbestimmung (ISO 13078-2:2016); Deutsche Fassung EN ISO 13078-2:2016
Overview
Dental furnaces are suitable for the manufacturing of metal-ceramic and partly also all-ceramic restorations for use in dentistry. Dental furnaces are particularly used for firing or sintering, respectively, of dental opaques, dentine and enamel materials to the respective compatible substructure materials. According to the current state of the art, the temperature of this process lies between 600 °C and 1 000 °C. The different calibration processes applied by the manufacturers of dental furnaces as well as the varying construction types of the dental furnaces currently on the market influence the firing result. Despite the fact that different dental furnaces can have identical digital external displays, different results regarding the degree of firing can be identified when processing the same ceramics under otherwise similar conditions. A different degree of firing not only causes differences that can be judged directly by the human eye (such as colour and transparency), but also deviations that cannot be detected by the eye. These are, for instance, the linear coefficient of thermal expansion, the bonding strength, the strength values and the acid solubility. Such changes may result in clinical failures (for example, fractures) as well as changed aesthetics of the dental ceramic restoration. The standard determines a degree of firing to be implemented by the user. It represents a test method for adapting the firing program of a dental furnace by determining the degree of firing of fired test specimens for a dental ceramic. The test method is suitable for powdered dental ceramics according to ISO 6872, Type I. The test method enables monitoring of the temperature control in the dental furnace by evaluating the firing degree of a dental ceramic. The test method is also suitable for evaluating the reproducibility of the firings in a dental furnace or for comparing several dental furnaces. The International Standard has been prepared by ISO/TC 106/SC 2/WG 1 "Dental ceramics" (secretariat: ANSI, USA), together with CEN/TC 55 "Dentistry" (secretariat: DIN). The committee responsible at DIN is Working Committee NA 014-00-07 AA "Keramiken" ("Ceramics") of NADENT.
