Clinical success and longevity of band and loop compared to crown and loop space maintainers

Aim: To prospectively evaluate the success and survival rates of band and loop (B&L) compared to crown and loop (C&L) space maintainers. Methods: Thirty-six children were divided into two groups (18 B&Ls and 18 C&Ls) matched for gender, age and the extracted tooth. For the study group, all clinical procedures were performed by the same paediatric dentist. Regular follow-up appointments were scheduled at 4–6 months. Comparisons in survival time and variables which might have affected the mean survival time were tested using Log rank and Chi-square tests. Results: A total of 16 girls and 20 boys (3.4–6.3 years old) were included. The overall failure rate was 53 %. For B&Ls, the failure rate was 83 % compared to 22 % for C&Ls. The main reason for failure of B&Ls was decementation (87 %), while for C&Ls, it was solder breakage (75 %). The mean survival time for B&Ls was 18.8 months, and for C&L, it was 40.4 months (p < 0.001). Conclusions: The failure rate and mean survival time for C&Ls were clinically and statistically significantly better than those for B&Ls. Depending on the clinical presentation of the abutment tooth and the intended life expectancy of the space maintainer among other factors, it is recommended that, where a space maintainer is indicated in the primary dentition, preference is given to C&L over B&L space maintainers.