To the best of knowledge, only 2 prospective studies, and 1 cross-sectional study have been reported which have seen the periapical healing after non surgical endodontic treatment in diabetic patients and their effect on HbA1c.

Because of the inconsistencies in data available from the literature and considering the limitations of cross-sectional studies, further studies, especially using a prospective design, are required.

So, aim is to investigate the effects of non surgical endodontic treatment on healing and systemic inflammation in individuals with and without diabetes.

Both the systematic review concluded that diabetics have significantly higher prevalence of RFT with RPL. An umbrella review concluded that DM is associated with the outcome of RCT and can be considered as a pre operative prognostic factor.

AP may contribute to low grade systemic inflammation associated with a generalized increase in systemic inflammatory mediators such as C-reactive protein (CRP), interleukin (IL)-1, IL-2, IL-6 and Immunoglobulin (IgA, IgG and IgM) levels .

It is already established that Diabetes mellitus (DM) and periodontitis are highly prevalent non-communicable diseases worldwide and yet they are closely inter-connected with common risk factors and plausibility of increased levels of systemic inflammation. It is evident that periodontitis significantly increases the risk of cardiovascular and renal complications in patients with type 2 diabetes mellitus (T2DM) . Higher serum high-sensitivity C-reactive protein (hsCRP) levels were reported in individuals with AP when compared to healthy controls . Also, there was a positive correlation of increased serum hsCRP levels with increasing severity of AP . A meta-analysis concluded that patients with AP had higher peripheral blood levels of CRP than controls and recommended the need for further studies to evaluate whether the treatment of AP can reduce serum CRP levels . Root canal treatment can reduce systemic inflammation and early endothelial dysfunction.

There is no published prospective interventional study evaluating the effect of root canal treatment on serum hsCRP levels in diabetic patients with AP.

Therefore, the aim of this study is to assess the impact of root canal treatment on HbA1c and serum hsCRP levels in diabetic adults with AP in comparison to healthy patients with AP.

Inclusion Criteria:

• Known patient of type 2 diabetes mellitus with HbA1c ≥6.5 %. Age between 30 to 65 years. Mature permanent posterior tooth having apical periodontitis requiring primary root canal treatment.

No evidence of systemic diseases other than diabetes being a risk factor for apical periodontitis.

A radiographic evidence of periapical radiolucency (minimum size,≥2mm x2mm) and a diagnosis of pulpal necrosis, as confirmed by negative response to cold and electrical tests.

No antibiotic therapy within the preceding one month.

Exclusion Criteria:

• Teeth with procedural errors, cracks, fractured teeth. patients with previously endodontically treated teeth with periapical radiolucencies.

Teeth that were not suitable for rubber dam isolation. smokers, pregnant patients. Patients with moderate and severe periodontitis. Systemic diseases other than diabetes being a risk factor for apical periodontitis.

Immunocompromised patients.