A superficial cavity/ initial White Spot Lesion can wait till the end of treatment as the continuous use of GC Tooth Mousse and judicious maintenance of oral hygiene will not allow the cavity to progress. But a deep cavity needs to be attended to immediately.
Next Steps
Send a clinical picture and an XRAY of the concerned tooth/ OPG that would have been done so as to have a proper assessment of the tooth.
Health Tips
Maintain oral hygiene, use orthodontic brushes, a mouthwash and have regular visits with your orthodontist.