Laser Doppler Flowmetry and Continuous Tissue Oxygenation Monitoring: Best of Vitality Tests?

This study aimed to explore the added value and usage of laser Doppler flowmetry (LDF) in conjunction with continuous tissue (arterial) oxygen saturation (SO2) monitoring, electrical pulp testing (EPT), cold stimulation (CS) testing, and apical X-rays (RX). LDF data were evaluated in relation to three different scenarios. LDF records of all four upper incisors from 30 randomly selected patients aged 21–40 were analysed in relation to the following scenarios: (a) simultaneous SO2 measurements using a pre-manufactured splint handled by an experienced LDF dentist, (b) EPT, and (c) CS. A total of 120 teeth were analysed, of which 11 were non-vital (7 denervated and 4 traumatised). Data assessment showed the following mean LDF values: vital teeth: 23.6 Perfusion Units (PU), SD 6.3 and SaO2 of 88.7%, SD 17.1. For non-vital teeth, the mean LDF value was 16.1 PU (SD 11.8) and the mean SO2 value was 70.8% (SD 31.9). The standard deviation was found to be twice as high for non-vital teeth as for vital teeth. No direct relationship was found between LDF and SO2 values at low SO2. For vitality discrimination, the ROC curves showed an area under the curve of 0.799 for LDF and 0.643 for SO2. EPT data assessment showed a mean value of 18.1 (SD 19.7) out of a possible score of 0–80. This was distributed as follows: seven non-vital teeth (80/80); 109 vital teeth; and four undecided teeth. This was compared to the LDF and SO2 results. The data assessment showed nine non-vital teeth, 108 vital teeth, and three undecided teeth in comparison to LDF and SO2 results. Conclusion: LDF and SO2 do not complement each other sufficiently in detecting non-vital teeth when the selection criteria are applied. While LDF clearly contributes, the vital or non-vital classification still depends on a combination of X-ray, sensitivity, and vitality tests.