Odontoblast markers and dentine reactions in carious primary molars with and without hypomineralised enamel defects

Background: Wnt/β-Catenin signalling and DMP1 have key roles in tertiary dentinogenesis. Aim: To compare the relationship between remaining dentine thickness (RDT), tertiary dentine thickness (TDT), β-catenin and dentine matrix protein 1 (DMP1) in carious second primary molar teeth with normal (SPM) and hypomineralised enamel (HSPM). Design: Extracted carious SPM and HSPM were fixed, sectioned (5 μm) and stained with haematoxylin and eosin or with indirect immunofluorescence for β-catenin and DMP1. Image analysis was performed to determine RDT, TDT, β-catenin and DMP1 intensity in the odontoblast layer and dentine-pulp complex. Results: Carious SPM (n = 11; mean RDT = 1536.1 μm) and HSPM (n = 12; mean RDT = 1179.9 μm) had mean TDT 248.6 μm and 518.1 μm, respectively (P =.02). There were no significant differences in intensity values in the odontoblast layer and dentine-pulp complex for β-catenin and DMP1 for both groups. Conclusion: There was no observable variation in Wnt/β-catenin and DMP1 expression between HSPM and SPM despite a statistically significant twofold increased TDT in HSPM compared with SPM that had similar RDT. Thus, the observed increased TDT in HSPM is more likely due to an earlier onset of repair processes rather than an amplified response to caries.