Residual polymerization stresses in human premolars generated with Class II composite restorations

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Polymer Chemistry

Background:

• Residual polymerization stress in resin composites can lead to restoration failure.
• Understanding the impact of different filling techniques is crucial for improving dental restoration longevity.

Purpose of the Study:

• To evaluate how various resin composite filling techniques influence residual polymerization stresses.
• To compare bulk versus incremental filling methods in Class II cavities.

Main Methods:

• Class II cavities were prepared in human premolars, and indentation cracks were introduced.
• Cavities were filled using bulk or incremental techniques with resin composite and adhesive.
• Tensile stresses were calculated from crack length measurements over 360 minutes post-filling.

Main Results:

• Incremental filling techniques generated significantly lower tensile stresses than bulk filling.
• Residual stresses primarily developed within 60 minutes after filling.
• The incremental technique filling the proximal portion first was most effective in reducing stress.

Conclusions:

• Incremental filling strategies are superior to bulk filling for minimizing polymerization stress in resin composite restorations.
• Optimizing filling techniques can enhance the clinical performance and durability of dental restorations.