There are hard dark brown lesions on the labial surface of all four primary cuspids in seven year old child, the teeth are not painful and scraping with spoon excavator yields only a few flecks of dried discoloured dentin. What are these lesions?

Arrested caries With the shift in the oral conditions, even ad­vanced lesions may become arrested. Arrested caries involving dentin shows a marked brown pigmentation and induration of the lesion . There are hard dark brown lesions, the teeth are not painful and scraping with spoon excavator yields only a few flecks of dried discoloured dentin.   Reference: TEXTBOOK Of PEDODONTICS Shobha Tandon page no 180