Optimizing light-cured composite through variations in camphorquinone and butylhydroxytoluene concentrations

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Dental composites are widely used restorative materials.
• Polymerization stress during setting can lead to marginal gaps and restoration failure.
• Controlling polymerization stress is crucial for improving the longevity of dental restorations.

Purpose of the Study:

• To investigate the combined effects of butylhydroxytoluene (BHT) and camphorquinone (CQ) on reducing polymerization stress in dental composites.
• To evaluate how varying concentrations of BHT and CQ influence mechanical properties and degree of conversion.
• To identify optimal combinations of BHT and CQ for enhanced dental composite performance.

Main Methods:

• Dental composite samples were fabricated using Bis-GMA, UDMA, TEGDMA, and silanized glass fillers.
• Sixteen experimental groups were created with varying concentrations of CQ (0.1-1.5%) and BHT (0.0-1.5%).
• Key properties including flexural strength, flexural modulus, degree of conversion, contraction stress, stress rate, and gel point were measured and analyzed using ANOVA.

Main Results:

• Low CQ and BHT concentrations yielded moderate mechanical properties and contraction stress with approximately 70% degree of conversion.
• Increasing BHT decreased contraction stress and degree of conversion while increasing gel point.
• Increasing CQ content steadily enhanced flexural strength and flexural modulus.
• Combinations of high CQ and BHT demonstrated superior mechanical properties alongside reduced stress values.

Conclusions:

• Butylhydroxytoluene (BHT) and camphorquinone (CQ) can be used in combination to modulate polymerization stress and mechanical properties of dental composites.
• Optimizing the concentrations of BHT and CQ is essential for achieving a balance between low polymerization stress and high mechanical performance.
• The findings suggest that specific ratios of BHT and CQ offer a promising strategy for developing advanced dental restorative materials with improved clinical outcomes.