Method: Ten human deciduous molar teeth with acute caries lesions were selected by a trained examiner. Caries depth was confirmed by radiographs. All teeth were cleaned and longitudinally sectioned in order to obtain at least two slices of approximately 1mm thickness, containing health and carious dentin. After polishing, dentin fluorescence (DIAGNOdent - Kavo) and Knoop microhardness were measured. The values considered for statistical analysis were the arithmetical means obtained after three repeated measures on each slice for health and carious dentin. The testes used were Mann-Whitney and Pearson correlation (α=0.05).
Result: It was observed that carious dentin showed lower values of hardness when compared to sound dentin (p<0,0001); but its fluorescence was higher (p<0,0001). When the relation between hardness and dentin fluorescence was tested, a strong negative correlation was observed for sound and carious dentin (r=-0,8303/p=0,0029; r=-0,8439/p<0,0001, respectively).
Conclusion: It's possible to conclude that dentin fluorescence increases as hardness values decrease and that DIAGNOdent can be an usefull clinical tool during carious dentin removal.