Clinical evaluation of salivary pH and caries detection using a caries detection device in children diagnosed with molar-incisor hypomineralization

Aims: Molar–incisor hypomineralization (MIH) is a developmental enamel defect characterized by reduced mineral density, increased porosity, and a higher susceptibility to dental caries. Objective assessment of enamel demineralization and its relationship with salivary factors remains clinically important. The primary objective of this study is to compare DIAGNOdent fluorescence values between children diagnosed with MIH and a healthy control group. The secondary objective is to evaluate the relationship between fluorescence values, salivary pH, and age at the tooth and surface levels. Methods: This cross-sectional study included a total of 110 children aged 6-15 years (55 with MIH, 55 healthy controls). The MIH diagnosis was made according to the criteria of the European Academy of Paediatric Dentistry (EAPD). The level of demineralization on tooth surfaces was measured using the DIAGNOdent Pen device on the mesial, distal, buccal, lingual/palatal, and occlusal surfaces. Three measurements were taken for each surface, and the highest value was recorded. Unstimulated saliva samples were collected to perform pH measurements. Data were analyzed using the Mann–Whitney U test, Chi-square test, and Spearman correlation analysis (p<0.05). Results: No significant differences were found between the MIH and control groups in terms of age, gender, and saliva pH level (p>0.05). However, significantly higher DIAGNOdent values were observed in the MIH group, particularly in the posterior teeth and the maxillary region (p<0.001). No significant differences were found between the groups regarding anterior teeth and the mandibular region. In both groups, weak negative correlations were observed between age and DIAGNOdent values in the anterior teeth, and weak positive correlations with pH, whereas these correlations were not significant in the posterior teeth. These findings were further confirmed by linear mixed-effects model analysis controlling for intra-individual variability, supporting that the surface-based analytical approach provides a more detailed and clinically relevant evaluation of hypomineralized enamel. Conclusion: In the presence of MIH, DIAGNOdent measurements show a marked increase, particularly in the posterior teeth, reflecting structural changes characteristic of hypomineralized enamel. The relationship between DIAGNOdent values and age and saliva pH varies depending on the tooth and surface type. Although saliva pH did not differ between groups, it may play a modulatory role in the pathogenesis of MIH. The DIAGNOdent device can be used as an auxiliary tool in the evaluation of MIH lesions; however, it should be interpreted in conjunction with clinical examination.