Abstract
Identifying the differences between active and inactive white spot caries lesions is presently a challenging task in clinical dentistry. White spot lesions are normally associated with demineralization that has happened (inactive) or is happening (active) to the tooth at a given time. In inactive white spot lesions, the demineralization is at rest and the infectious carious process is stopped. It is important to be able to differentiate an inactive lesion from an active one because inactive lesions can be treated without surgical methods. Avoiding unnecessary repair will preserve the natural structure of the tooth and increase its longevity. We have tested the ability of a concentrated, 11 molar Sodium Iodide (NaI) solution as a radiographic contrast agent to differentiate between active and inactive caries white spot lesions. The hypothesis is that concentrated NaI solution is likely to penetrate into the tooth structure of active, but not inactive, lesions, thereby providing a visual method for distinguishing the activity states. To test this hypothesis, two teeth (one human maxillary 1st molar and one maxillary 3rd molar) with visible white spot lesions were collected for analysis. Photomicrography, radiography and Scanning Electron Microscopy (SEM) assessments were used to study these specimens. Consistent with our hypothesis, radiographic images revealed a high penetration of NaI solution through the enamel of the 1st molar, which had an active white spot lesion, as confirmed by photomicrography and SEM analysis. However, minimal to no NaI penetration was observed through the enamel of the 3rd molar, which was confirmed to have an inactive white spot lesion. While this study is preliminary, new methods to identify active carious lesions have the potential to improve the management of caries and reduce unnecessary restorative measures.