[A randomized controlled clinical study on the immediate fabrication of band-and-loop space maintainers using a...

Objective: To fabricate pediatric band-and-loop space maintainers using a domestic computer aided design and computer aided manufacturing (CAD/CAM) system and evaluate their clinical application outcomes. Methods: A prospective randomized controlled trial was conducted. Fifty children with early deciduous tooth loss requiring band-and-loop space maintainer treatment at First Clinical Division, Peking University School and Hospital of Stomatology from October 2024 to June 2025 were selected. Participants were randomly allocated to the digital fabrication group or the conventional fabrication group using the sealed envelope method. For the digital fabrication group, space maintainers were designed and fabricated immediately with a domestic CAD/CAM system and then cemented in place; for the conventional fabrication group, space maintainers were made by bending and welding prefabricated loops with bands and subsequently cemented. All patients were followed up for 3 and 6 months to assess the effectiveness of space maintenance and periodontal health status were assessed. Results: A total of 50 patients were included in this study, including 30 males and 20 females (one female case was lost to follow-up), with the age of (7.7±1.7) years, with 55 retainers fabricated, 28 in the digital group and 27 in the traditional group (one case was lost to follow-up, leaving 26 for statistical analysis). The retainer retention rates at 3 months were 93% (26/28) in the digital group and 92% (24/26) in the conventional group, and all the detached maintainers were recemented. At 6 months, the retention rates were 93% (26/28) in the digital group and 96% (25/26) in the conventional group. No statistically significant differences in retention rate were observed between the two groups at the same follow-up time points (both P>0.05). The proportions of abutment teeth with a small plaque area on bands [82% (23/28) at 3 months, 96% (27/28) at 6 months] and without gingival inflammation [79% (22/28) at 3 months, 93% (26/28) at 6 months] in the digital group were significantly higher than those in the conventional group [58% (15/26) and 50% (13/26) respectively at 3 months, 35% (9/26) and 38% (10/26) respectively at 6 months] (all P<0.05). There were no statistically significant differences between the two groups in terms of space variation, caries incidence of abutment teeth, or the degree of loop subsidence (all P>0.05). Conclusions: Band-and-loop space maintainers fabricated with a domestic CAD/CAM system exhibit favorable clinical efficacy in space preservation for pediatric patients with early loss of deciduous teeth. Additionally, they offer advantages over conventional maintainers in plaque control and maintenance of gingival health compared with conventional maintainers.