The Featherstone laboratory pH cycling model: a prospective, multi-site validation exercise.

Area of Science:

• Biomimetic dental research
• In vitro caries models
• Fluoride efficacy testing

Background:

• Animal testing for dental caries research faces ethical and regulatory scrutiny.
• In vitro models are sought as reliable alternatives to animal studies.
• The Featherstone pH cycling model aims to replicate oral conditions for caries assessment.

Purpose of the Study:

• To validate the robustness of the Featherstone pH cycling model across three independent laboratories.
• To assess the utility of non-inferiority testing within this in vitro model.
• To confirm the model's suitability as an alternative to animal testing in caries research.

Main Methods:

• Cross-validation of the Featherstone pH cycling model in three independent laboratory settings.
• Testing the model's ability to represent the caries process and respond to fluoride.
• Evaluating the performance of known fluoride dentifrice formulations against controls.

Main Results:

• The model demonstrated consistent performance across all three laboratories.
• Clinically proven fluoride dentifrices performed as expected, confirming model validity.
• An attenuated fluoride formulation (NaF/CaCO3) was correctly identified as inferior to a standard fluoride control.

Conclusions:

• The Featherstone pH cycling model is robust and reproducible across independent laboratories.
• The model effectively discriminates between varying fluoride concentrations and formulations.
• This in vitro model shows significant promise as a non-inferiority test and an alternative to animal testing for evaluating anticaries agents.