Universal Bulk-Fill Composites: An Investigation into the Efficiency of Rapid Curing with Reversible...

Area of Science:

• Dental Materials Science
• Polymer Chemistry
• Restorative Dentistry

Background:

• Advancements in dental restorative materials focus on simplifying clinical procedures.
• Bulk-fill composites allow for deeper increments, reducing application time.
• Novel polymerization techniques aim to improve curing efficiency and material properties.

Purpose of the Study:

• To evaluate the degree of conversion (DC) and polymerization kinetics of new RAFT-modulated bulk-fill composites.
• To assess the suitability of these materials for rapid 3-second curing under high irradiance.
• To compare their performance at different depths (2 mm vs. 4 mm) against established fast-curing composites.

Main Methods:

• Utilized Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) spectroscopy for real-time DC measurement over 300 seconds.
• Modeled temporal DC evolution using an exponential sum function.
• Compared two novel bulk-fill universal composites with two established fast-curing composites.

Main Results:

• The novel bulk-fill composites exhibited DC results independent of sample depth or curing mode.
• All tested composites showed slightly slower polymerization kinetics in the gel phase at moderate irradiance or deeper layers.
• Equivalent final DC values were achieved by all composites within the 300-second observation period.

Conclusions:

• The novel RAFT-modulated bulk-fill composites are suitable for rapid 3-second curing with high irradiance.
• These materials offer simplified restoration processes for both deep posterior and anterior restorations.
• The study confirms the clinical potential of these advanced dental composites for efficient and aesthetic restorations.