A Diagnostic Accuracy Study of Laser Doppler Flowmetry for the Assessment of Pulpal Status in Children's Permanent Incisor Teeth

Introduction: The aim of this study was to assess whether laser Doppler flowmetry is more accurate than the conventional pulp sensibility tests (electric pulp test and ethyl chloride) in assessing the pulpal status of permanent anterior teeth in children and to identify the laser Doppler flowmetry's Flux cut-off threshold. Methods: A cross-sectional diagnostic accuracy study with randomization was performed and included 74 participants (8- to 16-year-old children). Participants had 1 maxillary central or lateral incisor with either a completed root canal treatment or an extirpated pulp and a contralateral tooth with vital pulp. Outcome measures included the sensitivity, specificity, and predictive values as well as the repeatability of all tests. Results: A significant difference between the Flux values for teeth with vital and non-vital pulps was found. The cut-off ratio for laser Doppler flowmetry was 0.6, yielding a sensitivity of 53% and a specificity of 33%, which were lower than the values of the electric pulp test (sensitivity = 83.8 %-94.6% and specificity = 89.2%-97.6%) and ethyl chloride (sensitivity = 81.1%-91.9% and specificity = 73%-81.1%). The repeatability of laser Doppler flowmetry, electric pulp testing, and ethyl chloride were 0.85, 0.86, and 0.81, respectively. Conclusions: Laser Doppler flowmetry was unable to differentiate between teeth with vital and non-vital pulps. The results of this study showed that there was a high probability for false results. Further development of laser Doppler flowmetry in assessing pulpal blood flow would be required before it could be recommended for clinical use, especially in children.