The 74-year-old was taken to another hospital block from her Cabin No. 621 for treatment on Saturday.
About an hour later, she was brought back to her cabin under tight security.
The dental treatment was provided to Khaleda under the supervision of Professor Quazi Billur Rahman, chairman of the Oral and Maxillofacial Surgery Department.However, it could not be known what type of treatment she has received.
In June, the BNP chairperson had received the dental treatment from the same department of the hospital for fungal infection in her tongue.
The former prime minister was transferred to the BSMMU on Apr 1 this year for treatment from the old jailhouse on Nazim Uddin Road. She has been in prison since February 2018 serving 17 year jail in two corruption cases.