the aim of the study is to evaluate the efficacy of guided biofilm therapy (GBT) for treatment of deep periodontal pockets.

the objectives are

1- To compare the change in the clinical periodontal parameters and microbiological parameters by using real time PCR for P. gingivalis, Aggregatibacter actinomycetemcomitans and Filifactor alocis among sites treated by GBT and conventional hand instrumentation after a period of 3 months and to assess the level of the selected periodontal pathogens in deep periodontal pockets and to estimate and compare deep periodontal pockets which need surgery after 3 months of non-surgical treatment by GBT and conventional hand instrumentation.

the hypothesis is whether there are no differences in in the clinical and microbiological parameters among sites treated by GBT and conventional hand instrumentation after a period of 3 months or there are differences in in the clinical and microbiological parameters among sites treated by GBT and conventional hand instrumentation after a period of 3 months.

The participants will be selected on a consecutive basis from patients referred to the Department of Periodontics, College of Dentistry, University of Baghdad.

For each patient, each site will be randomly assigned to either treatment protocol:

1. Sites treated with GBT.
2. Sites treated with conventional manual instrumentation only.

Inclusion Criteria:

1. Adult patients, aged more than 18 years.
2. No history of any systemic diseases.
3. Diagnosed with Stages 3 and 4 periodontitis according to the 2017 World Workshop on the Classification of Periodontal disease.
4. The presence of deep periodontal pocket ≥ 6 mm in two non-adjacent teeth.

Exclusion Criteria:

1. Smokers.
2. Pregnant and lactating mothers.
3. History of any previous subgingival instrumentation in the last 3 months.
4. The use of antibiotics/non-steroidal anti-inflammatory drugs in the last 3 months.
5. Regular use of medication to control systemic illness.
6. The presence of perio-endo lesion.