Background

External inflammatory root resorption (EIRR) is a frequent complication of traumatic dental injuries (TDI). The aim of this cohort study was to identify novel non-invasive markers of post-traumatic EIRR by assessing the changes in the pulp's blood flow and the composition of gingival sulcus fluid (GCF) in children after dental trauma.

Material and methods

Thirty-two children were enrolled and assessed within 48 h of a TDI to their permanent incisors and during an additional three visits over a 6-months follow up period. During each visit, a radiograph and laser Doppler flow (LDF) measurements of the pulp blood flow were performed on the injured tooth, and the GCF was sampled. The permanent first molar tooth of the same subject served as a control for the LDF measurements and the GCF sampling. Concentrations of IL-1α in the GCF were measured using enzyme-linked immunosorbent assays. Radiographs were used to confirm EIRR.

Results

EIRR occurred in fourteen (43.8%) teeth in 32 patients. The teeth with EIRR showed diminished LDF readings when compared with controls at all visits. The LDF readings of the injured teeth continued to decrease at follow up visits. In the EIRR group, levels of IL-1α in the GCF of teeth with EIRR were increased and significantly higher than those of the control teeth at the visit when EIRR was diagnosed. The IL-1α levels were significantly higher in the EIRR group when compared to the injured teeth of patients without EIRR at the last follow-up visit.

Conclusions

The occurrence of EIRR after mechanical trauma of permanent teeth with complete root development is accompanied by a significant reduction in the blood flow of the tooth's pulp. It is accompanied by an increase in concentrations of IL-1α in the GCF of EIRR affected teeth. The results of this pilot study identified the use of IL-1α in GCF and LDF as non-invasive markers of EIRR.