Subcutaneous tissue response of mice to calcium hydroxide‐based pastes combined with chlorhexidine or to chlorhexidine gel used as intracanal medication

Abstract

The purpose of this study was to evaluate the response of subcutaneous connective tissue of mice to calcium hydroxide‐based pastes with chlorhexidine digluconate (CHX) or to CHX gel. Seventy‐five mice were assigned to 5 groups. Each animal received 2 polyethylene tube implants as follows: Group I (n=10 tubes) ‐ calcium hydroxide paste (Calen®), Group II (n=10) ‐ Calen mixed with 0.5% CHX (n=10), Group III (n=10) ‐ Calen mixed with 2% CHX, Group IV (n=10) −2% CHX gel, Group V (n=10) empty tube for 7, 21, and 63 days. The tissues were removed and submitted to histological processing and analysis. On days 7, group IV showed more inflammatory cells then groups I, II and III (p<0.05 ‐ ANOVA and Tukey test). On days 21, there was no difference between groups I and II (p>0.05) and between groups III and IV (p>0.05), and the number of inflammatory cells was higher in these last two groups (p<0.05). On days 63, groups I and II showed less inflammatory cells, followed by III (p<0.05) and IV (p<0.05). On days 63, groups I, II and III showed regression of the initial inflammation and signs of repair. In group IV there was no regression of inflammation suggesting a persistent residual aggression from the material, even 63 days. In conclusion, the Calen and Calen + 0.5% CHX allowed best adequate tissue response, whereas the Calen + 2% CHX showed an intermediate tissue response and 2% CHX gel showed worst tissue response. Supported by PROPe‐UNESP.