(1) Background: Pulse oximetry (PO) is an effective method of dental pulp status monitorization but still lacks practical implementation in dentistry, as well as clear reference values for different tooth types. The study’s aim was to investigate the age-related variation of blood oxygen saturation (SpO2) from the dental pulp during different stages of tooth development in all types of primary and permanent teeth of children. (2) Methods: The pulps of 600 healthy primary and permanent teeth (incisors, canines, premolars, and molars) of patients aged 2−15 years were tested with an adapted PO device, and the results were statistically analyzed; (3) Results: Statistically significant differences (p < 0.05) were found between open-apex and closed-apex teeth and between the canines and other tooth types in both primary and permanent dentitions. (4) Conclusions: Values of SpO2 tended to decrease with age progression in both primary and permanent dentitions. Enamel and dentine thickness and their optical properties and the shape and volume of coronal pulp, which differed among tooth types, seemed to have some influence on the reading as well. The study indicates that factors such as the root development and the tooth type must be taken into account when establishing reference SpO2 values for the dental pulp.
Keywords: oxygen saturation; permanent teeth; primary teeth; pulse oximetry; root development; tooth type.