Dental Furnace Part 1: Test Method for Temperature Measurement with Separate Thermocouple

ANSI/ADA Standard No. 163 Executive Summary

What is ANSI/ADA Standard No. 163 about?

This standard specifies a test method for the calibration of dental furnaces that are suitable for the heat treatment of silica-based dental ceramic restorations.

What are the requirements I should know about the test method for temperature measurement with separate thermocouple of dental furnaces?

A different degree of firing does not only cause differences that can be judged directly by the human eye (e.g. color and transparency), but also deviations that cannot be detected by eye. These may include the coefficient of thermal expansion, strength, and solubility of the dental opaque, dentine or enamel materials, and the bonding strength to its substructure. Such changes may result in clinical failures (e.g. fractures) as well as discoloration and changed aesthetics of the dental ceramic restoration.

This standard levels the currently existing differences between the final calibration of the dental furnaces based on the factory of origin through a final adjustment (that has to be carried out by all manufacturers in an identical way) of the temperature control in the firing chamber by means of a thermocouple at e.g. 800°C.

What’s the bottom line?

Dental furnaces are suitable for the manufacturing of metal-ceramic and 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. The firing result obtained is influenced by the accuracy of the actual temperature, which may be influenced by the different calibration processes and construction material utilized by manufacturers. Use of a thermocouple and the test method included in the standard can assist in providing the final calibration for firing, which can help prevent defects and failures of the finished restoration.