The goal of this clinical trial is to compare the effect of cold atmospheric plasma versus sodium hypochlorite as irrigating solutions in necrotic single rooted teeth. The main questions it aims to answer are:
* Does the use of sodium hypochlorite solution or cold atmospheric plasma as root canal irrigant will have the same effect on the level of postoperative pain in necrotic single rooted teeth?
* Does the use of sodium hypochlorite solution or cold atmospheric plasma as root canal irrigant will have the same effect on the level of MMP -9 in necrotic single rooted teeth? Researchers will compare cold atmospheric plasma to sodium hypochlorite solution as root canal irrigant to see if cold atmospheric plasma works to have the same effect on the level of postoperative pain and levels of MMP -9 in necrotic single rooted teeth.
Participants will:
* be asked to rate their pain level according to the given instructions and will be asked to return for follow up after 2 days to hand the pain scale chart.
* be instructed to call the operator and will be permitted to take Ibuprofen 400 mg not more than 6 hours apart and to record their tablet intake within 48 hours postoperatively, in case of severe or persistent pain.
* be referred to the fixed prosthodontics department for final restoration.