In vitro fluoride dose-response study of sterilized enamel lesions.

Area of Science:

• Dental research
• Materials science
• Infection control

Background:

• Intra-oral models require disinfected enamel specimens.
• Current formalin disinfection methods raise infection control concerns.
• Alternative sterilization methods are needed for enamel specimens.

Purpose of the Study:

• To evaluate if autoclaved or gas-sterilized enamel lesions respond to fluoride similarly to alcohol-disinfected lesions.
• To determine the optimal sterilization method for enamel specimens in intra-oral studies.

Main Methods:

• Human enamel specimens were lesioned and divided into three groups: autoclaved, gas sterilized (ethylene oxide), and 70% ethanol disinfected.
• Specimens were treated with varying fluoride concentrations (0, 250, 1,100 ppm) in an in vitro remineralization/demineralization model for four weeks.
• Fluoride uptake, lesion depth, and mineral content changes were analyzed using microdrill biopsy and transverse microradiography.

Main Results:

• All specimen groups showed significant differences in fluoride uptake based on fluoride treatment.
• Autoclaved lesions did not yield dose-response data for mineral content changes.
• Gas sterilization and alcohol disinfection maintained enamel lesion responsiveness to fluoride.

Conclusions:

• Gas sterilization is the preferred method for sterilizing enamel specimens for intra-oral studies.
• Autoclaving significantly alters the responsiveness of enamel lesions to fluoride.
• Formalin and 70% alcohol are disinfectants, while gas sterilization provides effective sterilization without compromising lesion properties.