Radiopacity of computer-aided design/computer-aided manufacturing composite resin blocks

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Radiology

Background:

• Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) composite resins are widely used in restorative dentistry.
• Assessing their radiopacity is crucial for clinical diagnosis and monitoring restorations on radiographs.
• Variations in radiopacity can affect the diagnostic accuracy of dental imaging.

Purpose of the Study:

• To quantify and compare the radiopacity of sixteen CAD/CAM composite resin blocks against natural tooth structures (enamel and dentin).
• To identify the elemental composition of CAD/CAM blocks and determine which elements influence radiopacity.
• To provide insights for developing CAD/CAM materials with improved radiographic visibility.

Main Methods:

• Radiographic evaluation of sixteen CAD/CAM composite resin blocks, one ceramic block, and human teeth of identical thickness.
• Measurement of radiographic density for each material.
• Elemental analysis of CAD/CAM composite resin blocks to correlate composition with radiopacity.

Main Results:

• Significant differences in radiopacity were observed between CAD/CAM blocks, enamel, and dentin.
• Compared to enamel, five blocks were more radiopaque, two were similar, and ten were less radiopaque.
• Compared to dentin, ten blocks were more radiopaque, one was similar, and six were less radiopaque.
• Barium and strontium were identified in all tested CAD/CAM composite resin blocks intended for molars.

Conclusions:

• The radiopacity of CAD/CAM composite resin blocks varies considerably, with many exhibiting lower radiopacity than natural tooth enamel and dentin.
• The presence of heavy metals such as barium, strontium, and zirconium is suggested to be effective in enhancing the radiopacity of CAD/CAM composite resins.
• Further research into material composition can optimize CAD/CAM materials for better radiographic detection.