The small black spot you mentioned has been present for six years without holes suggests it may be an area of staining rather than active decay. However, it’s essential to differentiate between intrinsic stains (which occur within the tooth structure) and extrinsic stains (which are superficial).
If there is no progression in size or symptoms such as pain or sensitivity over these years, it may indicate that while there is some form of demineralization occurring (potentially incipient caries), it has not progressed into a full cavity.
Yes decay can indeed progress from enamel into dentin without forming an obvious hole initially. Regular dental check-ups are crucial for monitoring any changes in your oral health status and addressing potential issues before they cause harm