Fluoride treatment and microhardness of dentin

Area of Science:

• Dental Materials Science
• Biomaterials
• Cariology

Background:

• Dentin microhardness is a critical indicator of its structural integrity.
• Fluoride treatments are widely used in dentistry to prevent caries and strengthen tooth structure.
• Understanding the specific effects of different fluoride formulations and pH levels on dentin is crucial for optimizing treatment efficacy.

Purpose of the Study:

• To evaluate the impact of various fluoride treatments on the microhardness of human dentin.
• To compare the effects of acidulated phosphate-fluoride (APF) at different pH levels and stannous fluoride (SnF2) on dentin microhardness.
• To determine the optimal fluoride treatment strategy for enhancing dentin hardness.

Main Methods:

• Human dentin samples were subjected to different fluoride treatments, including APF at pH 3.0 and 4.0, and 0.4% SnF2.
• Microhardness testing was performed to quantify changes in dentin surface hardness after each treatment.
• Sequential treatments involving APF followed by SnF2 were also investigated.

Main Results:

• Treatment with APF at pH 3.0 resulted in significant dentin softening compared to water treatment (p < .05).
• APF at pH 4.0 and 0.4% SnF2 alone did not significantly alter dentin microhardness compared to water.
• Sequential treatment with APF (pH 4.0) followed by SnF2 led to significant dentin hardening (p < .05), with a highly significant difference compared to APF pH 3.0 and SnF2 alone (p < .001).

Conclusions:

• Acidulated phosphate-fluoride at pH 3.0 can induce detrimental softening of human dentin.
• Sequential application of APF (pH 4.0) and SnF2 is an effective method for significantly hardening dentin.
• The sequential APF-SnF2 treatment protocol is recommended for clinical applications aimed at increasing the microhardness of exposed dentin surfaces.