Effect of calcium hydroxide paste on controlling endodontic interappointment emergencies

Objective To compare the clinical effect of calcium hydroxide paste on intracanal dressing medication for teeth with chronic periapical periodontitis with that of formocresol. Methods 260 permanent teeth with chronic periapical periododontitis were selected and divided randomly into calcium hydroxide paste group (A group) and formocresol group (B group).The periapical signs and symptoms were recorded and radiographs were taken. After root canal preparation,the calcium hydroxide paste was used as an intracanal dressing medication for one week in A group and the formocresol cotton point was used in B group.During the course of canal treatment,the clinical findings were assessed with clinical periapical index(CPI) and the cases were followed up for eighteen months. Results There was significant difference between A and B group (P0.01). A group was better the B group. There was no siginificant difference between two group of effective rate after following up eighteen months(P0.05). Conclusion As an intra-canal sterilization medication, calcium hydroxide can reduce the occurrence of endodontic interappointment emergencis in teeth with chronic periodontitis.