Effects of clear aligners and traditional removable appliances on oral microbiome in mixed dentition: a comparative study

Abstract

Abstract Background This prospective study aims to investigate the comparative effects of clear aligners (CA) and traditional removable appliances (RA) on the cariogenic risk of patients in mixed dentition, focusing on the oral microbiome. Methods 25 children were included and assigned into CA and RA groups. Supragingival plaque and saliva samples were collected, and clinical parameters including Decay-missing-filled teeth index (DMFT), Plaque Index (PI) and Gorelick Index (GI) were recorded before treatment (T0) and after 6-month follow-up (T1). DNA was extracted from supragingival plaque and saliva and analyzed via 16S rDNA gene sequencing. Results Clinical parameters showed no statistically significant difference between groups at each time point or within group over time (p > 0.05). In both RA and CA groups, saliva exhibited significantly higher alpha diversity compared to supragingival plaque at T1, as indicated by the significantly higher Chao1 and Shannon indexes (p 0.05, Adonis). At the genus level, Lactobacillus exhibited a statistically significant increase in saliva and supragingival plaque of group RA from T0 to T1 (p 0.05). At T1, Lactobacillus levels were comparable between groups, whereas species-level analysis revealed distinct cariogenic species. Conclusion Both clear aligners and traditional removable appliances resulted in elevated cariogenic risk of patients in mixed dentition at the microbial level. Distinct alterations in cariogenic species were observed to be induced by various orthodontic appliances.

Keywords

• Clear aligner appliance
• Removable orthodontic appliance
• Dental caries
• Mixed dentition
• Interceptive orthodontics
• Oral microbiota