Selenium intracanal dressing: effects on the periapical immune response

Objectives To evaluate the selenium (Se) behavior when used as an endodontic dressing in teeth with pulp necrosis. Additionally, its effects was also compared with the calcium hydroxide (C.H.), which is used globally as a root canal dressing, and the combination of the C.H. with Se (C.H. + Se). Materials and methods The sample consisted of 60 patients requiring endodontic treatment who were divided into groups, i.e., without intracanal medication (empty) and with medications as follows: selenium (Se), calcium hydroxide (C.H.), and calcium hydroxide + selenium (C.H. + Se) (n = 15). After the coronary opening, three absorbent paper points were placed in the RCS and maintained for 2 min for microbial evaluation. Following the cleaning and shaping procedures, new paper points were introduced into the root canal system, passing passively through the root apex (2 mm) into the periapical tissues for 2 min, for immune evaluation. The collections were performed again 15 days later. Real-time PCR quantified the expression of the prokaryotic 16S ribosomal RNA. The 16S mRNA was evaluated before the cleaning and shaping procedures and 15 days later in the groups treated with or without medication. Results A significant reduction in the microbial load was observed only in the groups that received endodontic dressing (p < 0.05). The cytokines IFN-gamma, TNF-alpha, IL-1 alpha, IL-17A, IL-10, IL-6 and MCP-1, were also quantified by real-time PCR. There was an increase in the gene expression level of the cytokines (T15) TNF-alpha and IL-10 in the C.H. group compared to the other groups (p < 0.05). The IFN-gamma mRNA expression was reduced in the groups treated with the medications (Se, C.H., and C.H. + Se). Conclusions The findings of the present study indicate that in the case of treatment over multiple sessions, the use of root canal dressing is essential to avoid the root canal system (RCS) microbial recolonization. Selenium potentiated the effects of calcium hydroxide inducing an anti-inflammatory response in periapical tissues.

Automated summary

The study found that using selenium as a root canal dressing significantly reduced microbial load, and selenium also potentiated the effects of calcium hydroxide, inducing an anti-inflammatory response in periapical tissues.