[Effect of pulp revascularization on CCL21, IFN-γ-inducible protein 10 in chronic periapical periodontitis]

To investigate the effect of pulp revascularization on the levels of CCL21 and IFN-γ-inducible protein 10（IP-10）in chronic periapical periodontitis.

One hundred patients with chronic periapical periodontitis treated from September 2018 to May 2019 were selected as the research subjects. They were divided into two groups by using random number table method. The patients in both groups were taken cone-beam CT(CBCT) film for filing before operation. Patients in the experimental group were treated by pulp revascularization, while patients in the control group were treated by apexification. The level of CCL21 and IP-10 was measured within 4 weeks. The results of operation, the ratio of crown to root and the thickness of root canal wall were analyzed. Statistical analysis of the data was conducted with SPSS 25.0 software package.

CCL21 and IP-10 levels of the two groups increased in the course of 1-3 weeks, but decreased after 4 weeks. CCL21 levels were significantly different at 2 weeks, 3 weeks and 4 weeks(P<0.05), but there was no significant difference at one week(P<0.05). There was no significant difference in IP-10 level between the two groups at 1, 2 and 3 weeks of treatment(P<0.05), but there was significant difference at 4 weeks of treatment (P<0.05). The success rate of the experimental group was 90% and that of the control group was 50%，there was a significant difference between the two groups(P<0.05). There was no significant difference in the ratio of crown to root and the thickness of root canal wall between the two groups(P<0.05).

For chronic periapical diseases, pulp revascularization, apical induction can promote the secretion of chemokines CCL21 and IP-10 in the early stage of treatment, the level of CCL21 changes greatly in the early stage of treatment, while changes of IP-10 can be seen in the later stage.