Overview
ISO 13078-2:2016 - "Dentistry - Dental furnace - Part 2: Test method for evaluation of furnace programme via firing glaze" defines a practical test method to determine and adapt the degree of firing for powdered dental ceramics (Type I, per ISO 6872). The standard provides a repeatable procedure for preparing test specimens, firing them in a dental furnace, and evaluating the firing result by visual comparison with a manufacturer-provided reference sample. Its purpose is to monitor and validate temperature control, reproducibility of firings, and to adjust furnace programmes so restorations achieve the intended color, translucency and material properties.
Key Topics and Requirements
- Scope: Applicable to powdered dental ceramics (ISO 6872, Type I) for glaze/dentine firings; intended to adapt firing programmes and assess furnace reproducibility.
- Definitions: Degree of firing classified as under-fired, correctly fired, or over-fired based on surface/edge state, color, transparency and edge rounding.
- Materials: powdered dental ceramic (transparent, optionally colored), mixing liquid (e.g., ISO 3696 water or alcohol), firing tray, firing pins, firing underlay (firing cotton or platinum foil), reference sample.
- Specimen preparation: Use a defined mould/device to produce cylindrical specimens (typical: 16 mm diameter × 1.6 mm thickness) to ensure consistent comparison.
- Furnace setup & firing data: Manufacturer must provide firing parameters - furnace type, pre-drying (readiness) temperature, heating rate or heating time under vacuum, vacuum level, firing temperature and holding time.
- Evaluation method: Visual comparison of fired test specimens versus the reference sample assessing color, transparency, surface lustre, shrinkage and edge stability; use this to determine whether standard firing data can be adopted.
- Correction procedure: If degree of firing differs, adjust maximum firing temperature and/or heating time in a systematic series of firings to match the reference specimen.
- Instrumentation/controls: Decouple specimens from the tray (firing pins), use coated platinum foil where appropriate (Al2O3), keep unchanged variables constant during correction firings.
Applications and Users
- Dental laboratories validating and calibrating dental furnace programmes before production.
- Dental ceramic manufacturers supplying reference samples and firing data.
- Dental furnace manufacturers and service technicians verifying temperature control, reproducibility and inter‑furnace comparability.
- Quality assurance teams performing pre-production checks to avoid clinical failures related to improper firing (e.g., color deviation, reduced strength, poor bonding).
Related Standards
- ISO 6872 - Dental ceramic materials (powdered ceramic classification)
- ISO 13078 (Part 1) - Test method for temperature measurement with separate thermocouple
- ISO 3696 - Water for analytical laboratory use
- ISO 2768‑1 - General tolerances (reference for dimensions)
Keywords: ISO 13078-2:2016, dental furnace, firing glaze test method, degree of firing, powdered dental ceramic, ISO 6872, furnace calibration, dental laboratory quality control.
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