Microleakage around a low-shrinkage composite cured with a high-performance light

Area of Science:

• Restorative Dentistry
• Dental Materials Science

Background:

• Microleakage remains a significant challenge in Class V restorations, potentially compromising longevity and pulp vitality.
• Minimizing polymerization shrinkage is crucial for improving marginal integrity and reducing secondary caries.
• Novel light-curing strategies and composite materials are continuously being developed to address these issues.

Purpose of the Study:

• To evaluate the microleakage of a new low-shrinkage resin-based composite.
• To compare its performance against a conventional composite under different curing conditions.
• To assess the impact of high-intensity light curing versus conventional and soft-start regimes on marginal seal.

Main Methods:

• Forty-two premolar and molar teeth underwent Class V cavity preparation, half in enamel and half in dentin/cementum.
• Restorations were placed using either a low-shrinkage or conventional composite with two bonding agents.
• Curing protocols included high-intensity, soft-start, and conventional light regimes, followed by thermocycling and microscopic leakage assessment.

Main Results:

• No microleakage was observed at enamel margins across all groups.
• All groups exhibited microleakage at gingival margins.
• The low-shrinkage composite cured with high-intensity light showed significantly less gingival microleakage than the conventional composite cured with a conventional light source.

Conclusions:

• The use of low-shrinkage composite with high-intensity curing does not eliminate gingival marginal microleakage.
• The tested low-shrinkage composite, when cured with high-intensity light, may provide clinical benefits where time efficiency is paramount.
• Further research is warranted to optimize curing protocols and material formulations for enhanced marginal seal in dentin/cementum-based preparations.