Lack of association between LTF gene polymorphisms and different caries status in primary dentition.

OBJECTIVE: Dental caries is related to cariogenic bacteria, salivary components, oral hygiene and host susceptibility. Lactoferrin is an important antimicrobial glycoprotein in saliva; however, the role of the LTF gene in caries susceptibility is unclear. We investigated the association between LTF polymorphisms and the severity of caries. DESIGN: Our study included 910 healthy paediatric subjects (aged 24-48 months) categorised into three groups: 403 with no caries or white-spot lesions; 230 with moderate caries (8 </= dmft </= 12); and 277 with severe caries (13 </= dmft </= 20). Information regarding the subjects' oral habits was gathered using questionnaires. The LTF rs1126477 and rs1126478 polymorphism alleles were genotyped by Sanger sequencing. RESULTS: The three groups showed no significant differences in LTF polymorphisms alleles, genotypes or haplotypes distribution. Multifactor dimensionality reduction analysis showed that the interactions between breastfeeding for a duration >24 months, night feeding >24 months and high frequency of sweet food intake increased the risk of caries (p = 0.0014); however, we detected no interaction effect between the LTF polymorphisms and oral habits on caries susceptibility. CONCLUSIONS: The LTF rs1126477 and rs1126478 polymorphisms showed no association with the different levels of caries risk in our Chinese paediatric cohort.