Evaluation of ultrasonic and mechanical methods for assessing dentin demineralization in children's permanent teeth in vitro

Relevance. With the advent of advanced methods for functional diagnostics, dentists have gained new opportunities for detecting carious lesions. However, the diagnostic sensitivity of these methods requires further investigation

Purpose. To evaluate the condition of intact and demineralized dentin in children's permanent teeth using both ultrasonic and mechanical methods.

Materials and methods. Divided cross-section" models were created from premolars extracted from children for orthodontic purposes. After a 20-day exposure to a demineralizing buffer solution with a pH of 4.5, both the intact and demineralized dentin cross-sections were tested using ultrasonic and mechanical methods.

Results. Statistically significant differences were observed in the mean ultrasonic signal speed C between two independent sample groups: intact dentin (Group 1) and demineralized dentin (Group 2), based on Mann-Whitney U-test calculations (p = 0.01). In Group 2, the mean value of C was 27% lower compared to Group 1. Additionally, significant differences were found in the mean ultimate strength σ between two independent groups: intact dentin (Group 3) and demineralized dentin (Group 4), with Group 4 showing a 29.5% reduction in the mean σ value, according to Mann-Whitney U-test calculations (p = 0.01).

Conclusion. Demineralization leads to significant changes in both the ultrasonic and mechanical properties of dentin. Statistical analysis of the laboratory test results using the "divided cross-section" model supports the effectiveness and diagnostic sensitivity of the methods applied for evaluating the extent of dentin demineralization. 

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