Dental Enamel Remineralisation as a Function of Fluoride Treatment: Microcomputed Tomography and Conventional Radiography

Abstract

Background: Dental caries is one of the most prevalent chronic oral diseases in the world. Acidic microenvironment in caries leads to the dissolution of hydroxyapatite from tooth enamel, a process known as demineralisation. Owing to this demineralisation, incipient enamel caries is clinically detected as white spot lesions (WSLs). Early detection of such carious lesions can help undertake relevant treatment approaches to remineralise the affected region. Method: This research was to assess in-vitro the effect of fluoride treatment on the remineralisation of natural WSLs in human enamel over 8 days. At the same time, this study aimed to compare the efficacies of two remineralisation detection methods, namely, Microcomputed Tomography and conventional radiography. Nine WSL and 7 control human premolars/molars were used for this study. The formulation used was2 mmol/l CaCl2, 1.2 mmol/l, KH2PO4, 150 mmol/l NaCl, and NaF at 0.05 mmol/l. Results: The mineral profiles of enamel sub-surface lesions observed in the present study were consistent with published reports. However, the WSL samples did not show a consistent improvement in mineral content upon remineralisation with 0.5 ppm sodium fluoride. One third of the experimental group showed significant remineralisation results. Although, four of the nine WSL samples showed no changes in mineral content or radiographic data upon remineralisation. Two had no detectable lesions and also did not show any significant variation in the mineral profile upon remineralisation. Conclusion: It was found that radiographs could not reliably detect either the incipient carious lesions pre-treatment, or the improvement in mineralisation after remineralisation treatment. Thus, radiographical data may not be useful for diagnosing early enamel WSLs or the detection of remineralisation. However, Micro-Ct results showed the highest desirable outcomes in remineralisation detection in this present study. It has also been found that visual inspection is the best detection tool for WSLs in our daily practice.