A Review of Mechano-Biochemical Models for Testing Composite Restorations.

Area of Science:

• Biomaterials Science
• Dental Materials
• Oral Health Research

Background:

• Dental restorations face harsh mechano-biochemical conditions in the oral cavity, leading to degradation and failure.
• Secondary caries and fracture are primary failure modes for resin composite restorations.
• Understanding degradation mechanisms requires laboratory studies using simplified models.

Purpose of the Study:

• To review and compare four main models for studying resin composite restoration degradation: animal, human in vivo/in situ, in vitro biofilm, and in vitro chemical models.
• To discuss the characteristics, advantages, and disadvantages of each model.
• To highlight the importance of synchronized and clinically calibrated accelerated laboratory models.

Main Methods:

• Review of existing literature on various models for dental restoration degradation studies.
• Analysis of model characteristics, including their ability to simulate oral conditions (demineralization, hydrolysis, collagen degradation) using acids and enzymes.
• Discussion on the calibration of in vitro models against clinical data.

Main Results:

• Four primary models (animal, human in vivo/in situ, in vitro biofilm, in vitro chemical) exist for studying dental restoration degradation.
• The tooth-restoration interface is a critical weak point.
• Accelerated laboratory models require synchronized degradation components and calibration with clinical data to be predictive.

Conclusions:

• In vitro models are valuable for understanding resin composite degradation but must accurately mimic oral conditions.
• Synchronizing degradation rates and calibrating with clinical data are crucial for developing representative and predictive accelerated laboratory models.
• Further comparative studies of in vivo and in vitro models are needed for accurate laboratory calibration.