Core build-up resin composites: an in-vitro comparative study

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Restorative Dentistry

Background:

• Resin composites (RCs) are widely used for core build-ups under full crowns.
• Limited independent data exists to guide practitioners in selecting core build-up resin composite (CBU-RC) materials.
• Understanding the mechanical properties of CBU-RCs is crucial for successful clinical application.

Purpose of the Study:

• To compare the flexural properties of various commercially available CBU-RCs.
• To evaluate light-cure, self-cure, and dual-cure CBU-RCs against conventional light-cure RCs.
• To determine the influence of light-curing on the flexural properties of dual-cure CBU-RCs.

Main Methods:

• Flexural modulus (Eflex) and flexural strength (σf) were tested using three-point bending (n=20).
• Materials included light-cure, self-cure, and dual-cure CBU-RCs, alongside conventional light-cure RCs.
• Thermogravimetric analysis determined inorganic filler content (n=3).

Main Results:

• Significant differences in Eflex and σf were found between conventional RCs and CBU-RCs (p < .0001).
• Light-cured RCs exhibited higher Eflex than self- and dual-cure RCs; no clear trend for σf.
• A strong linear correlation existed between inorganic filler content and Eflex (R²=0.85, p < .0001).

Conclusions:

• Light-curing positively influenced the Eflex of dual-cure CBU-RCs.
• Substantial variations in flexural properties, particularly Eflex, were observed among tested materials.
• The findings raise questions about the suitability of some CBU-RCs for replacing dentin in extensive tissue loss scenarios.