Work

Association between untreated permanent-tooth caries burden and salivary 8- hydroxy-2′-deoxyguanosine in twelve-year-old children: an exploratory cross- sectional biomarker study

Year: 2026

Type: preprint

Abstract: Background Dental caries may alter salivary oxidative-stress biomarkers, but evidence for salivary 8-hydroxy-2′-deoxyguanosine (8-OHdG) in children with permanent dentition is limited. We examined whether upper-tail untreated permanent-tooth caries burden was associated with salivary 8-OHdG in twelve-year-old children. Methods This exploratory cross-sectional study included an oral-health survey of 190 children from two schools in Ulaanbaatar, Mongolia, with a nested non-representative biomarker substudy of 45 children enriched for low and high untreated caries burden. Untreated decay was represented by the number of decayed permanent teeth (D); D ≥ 7 defined the parent cohort’s upper tail. The primary HC3-robust log-linear model compared D ≥ 7 with D < 7, adjusting for school and salivary flow. Sensitivity models additionally adjusted for plaque, gingivitis and sex and restricted analyses by residential duration and observed caries phenotype. Results The biomarker sample comprised 27 children with D = 0, three with D = 1–2 and 15 with D ≥ 7; none had D = 3–6. D ≥ 7 was associated with 2.62-fold higher salivary 8-OHdG (geometric mean ratio [GMR] 2.619, 95% CI 2.213–3.099; p < 0.001). Estimates remained similar after plaque adjustment (GMR 2.564), adjustment for plaque, gingivitis and sex (GMR 2.465), restriction to residence ≥ 3 years (GMR 2.576), residence ≥ 5 years (GMR 2.539), and D = 0 or D ≥ 7 only (GMR 2.713); all p < 0.001. The school indicator was not independently associated with 8-OHdG. A complementary continuous model gave a GMR of 1.105 per additional decayed tooth, but crossed the unobserved D = 3–6 interval. Conclusions Upper-tail untreated permanent-tooth caries burden was strongly associated with salivary 8-OHdG in this criterion-enriched biomarker sample. The finding extends pediatric oral-redox evidence to twelve-year-old children with permanent dentition and supports careful measurement of active caries when interpreting salivary oxidative DNA-damage markers. The cross-sectional, non-representative design does not establish causality, diagnostic utility or a population dose-response.

Source: Research Square

DOI: 10.21203/rs.3.rs-10718762/v1