Lesion sterilisation and tissue repair with chloramphenicol, tetracycline, zinc oxide-eugenol paste compared to zinc oxide-eugenol pulpectomy in primary molars: Two-year follow-up findings of a multicentre non-inferiority randomised clinical trial

Background: Chloramphenicol, tetracycline, zinc oxide (CTZ) paste has been widely used, particularly in Latin America, in Lesion Sterilization and Tissue Repair (LSTR) procedures in primary molars. However, reports on its long-term efficacy are scarce. Aim: This multicentre non-inferiority randomised trial compared the efficacy of LSTR using CTZ paste with conventional zinc oxide-eugenol (ZOE) pulpectomy in primary molars. Design: 199 primary molars from children aged 3 to 9 years were randomised to the CTZ or ZOE groups. The primary outcome was clinical and radiographic success at 24 months. Clinical time, children's behaviour, immediate discomfort and postoperative pain were also evaluated. The main analysis followed the intention-to-treat (ITT) principle, comparing success proportions with the Miettinen-Nurminen method, considering a prespecified non-inferiority margin of 15% (p < 0.05). Results: Overall success rates in the ITT population were 64.3% for CTZ and 58.7% for ZOE, with a difference of 5.6% (95% CI: -9.3 to 20.4; p<0.01). Mean; standard deviation clinical time was significantly shorter in CTZ (36.3; 9.8 min) than in ZOE (63.0; 16.3 min) (p<0.01). Children's behaviour, immediate discomfort and postoperative pain were similar between groups (p>0.05). Conclusion: LSTR with CTZ paste was non-inferior to conventional ZOE pulpectomy after 24 months of follow-up.