Direct measurement of time-dependent anesthetized in vivo human pulp temperature

• Actual in vivo human coronal pulp temperature values were obtained.
• The cooling effects of cavity preparation on in vivo pulp temperature were assessed.
• In vivo human coronal pulp temperature values are lower than the human body core.
• In vivo pulp temperature values had less variation than in vitro studies.
• Use of a water-cooled high-speed handpiece reduces in vivo pulp temperature.

ObjectivesHuman intrapupal tooth temperature is considered to be similar to that of the body (≈37 °C), although the actual temperature has never been measured. This study evaluated the in vivo, human, basal, coronal intrapulpal temperature of anesthetized upper first premolars.MethodsAfter approval of the local Ethics Committee was obtained (protocol no. 255,945), upper right and left first premolars requiring extraction for orthodontic reasons from 8 volunteers, ranging from 12 to 30 years old, received infiltrative and intraligamental anesthesia. The teeth (n = 15) were isolated using rubber dam and a small, occlusal preparation was made using high-speed handpiece, under constant air–water spray, until a minute pulp exposure was attained. The sterile probe from a wireless, NIST-traceable, temperature acquisition system (Thermes WFI) was inserted directly into the coronal pulp. Once the probe was properly positioned and stable, real-time temperature data were continuously acquired for approximately 25 min. Data (°C) were subjected to 2-tailed, paired t-test (α = 0.05), and the 95% confidence intervals for the initial and 25-min mean temperatures were also determined.ResultsThe initial pulp temperature value (31.8 ± 1.5 °C) was significantly lower than after 25-min (35.3 ± 0.7 °C) (p < 0.05). The 95% confidence interval for the initial temperature ranged from 31.0 to 32.6 °C and from 35.0 to 35.7 °C after 25 min. A slow, gradual temperature increase was observed after probe insertion until the pulp temperature reached a plateau, usually after 15 min.SignificanceConsistent coronal, human, in vivo temperature values were observed and were slightly, but significantly below that of body core temperature.