In-vitro pulp chamber temperature rise during composite resin polymerization with various light-curing sources

Area of Science:

• Dental Materials Science
• Biomaterials
• Restorative Dentistry

Background:

• Composite resins are widely used in dental restorations.
• Visible light polymerization is standard for curing dental composites.
• Pulp chamber temperature elevation during curing is a clinical concern.

Purpose of the Study:

• To measure pulp chamber temperature increases during composite resin polymerization.
• To compare temperature changes induced by various visible light-curing units.
• To assess the thermal effects of different light-curing technologies on the dental pulp.

Main Methods:

• In vitro study using extracted molar teeth with a 1 mm dentin layer.
• Composite resin cured with six different visible light-curing units (Heliolux II, QHL 75, Astralis 5, Optilux 500, Elipar Highlight, ADT 1000 PAC).
• Pulp chamber temperature measured using a K-type thermocouple; statistical analysis via ANOVA and Dunnett t-test.

Main Results:

• Significant variations in pulp chamber temperature increase were observed among curing units.
• Higher energy output units (Astralis 5, Elipar Highlight, Optilux 500, ADT 1000 PAC, QHL 75) induced greater temperature rises than the conventional unit (Heliolux II).
• Maximum temperature changes ranged from 2.9°C to 7.8°C depending on the light-curing unit and duration.

Conclusions:

• High-energy output visible light-curing units cause significantly higher pulp chamber temperature increases.
• Clinicians should be aware of the potential thermal hazard to the pulp during composite resin polymerization.
• Careful selection and use of light-curing units are necessary to minimize risks to the dental pulp.