porcelain firing
The controlled high-temperature heat treatment in a porcelain furnace that sinters ceramic powder into a dense, translucent restoration layer.
Full Definition
Porcelain firing is the process by which ceramic powders applied to a restoration framework are transformed in a porcelain oven (furnace) through a precisely programmed temperature cycle into a fused, translucent material. Multiple firings are typically performed—opaque, dentine, incisal, glaze—each with its own temperature, vacuum, and hold-time settings. The firing programme must be calibrated regularly, as variations in furnace performance are a leading cause of shade and fit discrepancies in completed restorations. Editors should distinguish 'porcelain firing' (the layering/build-up process) from 'sintering' (the densification of pre-milled ceramic blocks) and from 'glazing' (the final surface-finishing fire).
Usage
Usage note: Do not use 'porcelain firing' synonymously with 'sintering' (which applies to milled CAD/CAM blocks) or 'glazing' (which is a subset, final-surface fire). Each term denotes a distinct process.
In Context
- "The technician recorded the porcelain firing schedule—including peak temperature and vacuum onset—in the case file." — Laboratory Case Record
- "A warped furnace tray distorted the restoration during porcelain firing, necessitating a remake." — Laboratory Defect Report