How much radiation of ct scan is safe?

I have taken 3 dental CBCT scan from June to December 2020. I had taken a neck CT scan of neck ok December. I have lower jaw pain under ear and neck since month of May..I went to various doctors and no answers yet. I have been to dentist and they took dental cbct scan. I have taken 3 dental Cone beam CT scan so far in the last 7 months. I have taken one ct neck last month.that makes count as 4. I have taken the third cbct dental scan and neck ct scan in December. I need some dental second opinion for my pain. I asked few dentist office. They are not accepting my old cbct scan and they said they will take their own CBCT scan. So I can't give them my old scans. I have a disc which has the old scan. I don't know if I can get another cbct now? Is it safe? How many dental ct and normal CT safe in an year? Within short time. Please share the inputs doctors.