IADR Abstract Archives
Coldness Changes Transmitted-light Plethysmography Values In Young Adult Human Teeth
Objectives: Pulpal microcirculatory system plays roles in maintaining tissue homeostasis and in undergoing a dynamic response to injury. It is significant to determine the vitality of the dental pulp on the basis of dental microcirculation, which plays an essential role in maintaining the health of dental pulp. Transmitted-light plethysmography (TLP) is a non-invasive objective optical method that utilizes a single light-emitting diode to detect blood volume changes in the dental pulp.
The objectives of this experiment were (1) to detect pulpal blood flow with TLP in healthy permanent maxillary central incisors of young adults, and (2) to assess the changes in TLP pulse waves by innocuous coldness.
Methods: Twenty healthy permanent maxillary central incisors in 20 young adult volunteers (aged 26-35 years) were examined, approved by the Ethical Committee of the Graduate School of TMDU. An individual acrylic resin cap was fitted to each experimental tooth, and the photodiode and LED were fixed through a hole made on the labial and palatal side, respectively, of the cap. A third hole was made on the labial 1/3 of the cap to put cold water (0°C) soaked cotton onto tooth labial surface. TLP with 525 nm and finger photoplethysmography (FPP) were simultaneously recorded while subjects were in supine position. Cold water was applied ten times in 20-second intervals.
Results: (1) TLP pulse waves synchronous with FPP were recorded from all incisors.
(2) The TLP pulse wave was suddenly decreased following the cold water application and returned to its normal level after a few seconds in every interval. Each subject felt just coldness, not pain after each time of cold water application.
Conclusions: Application of innocuous coldness induced transient decrease of the TLP amplitude, representing reversible reduction of pulpal blood flow, in young adult human teeth.
The objectives of this experiment were (1) to detect pulpal blood flow with TLP in healthy permanent maxillary central incisors of young adults, and (2) to assess the changes in TLP pulse waves by innocuous coldness.
Methods: Twenty healthy permanent maxillary central incisors in 20 young adult volunteers (aged 26-35 years) were examined, approved by the Ethical Committee of the Graduate School of TMDU. An individual acrylic resin cap was fitted to each experimental tooth, and the photodiode and LED were fixed through a hole made on the labial and palatal side, respectively, of the cap. A third hole was made on the labial 1/3 of the cap to put cold water (0°C) soaked cotton onto tooth labial surface. TLP with 525 nm and finger photoplethysmography (FPP) were simultaneously recorded while subjects were in supine position. Cold water was applied ten times in 20-second intervals.
Results: (1) TLP pulse waves synchronous with FPP were recorded from all incisors.
(2) The TLP pulse wave was suddenly decreased following the cold water application and returned to its normal level after a few seconds in every interval. Each subject felt just coldness, not pain after each time of cold water application.
Conclusions: Application of innocuous coldness induced transient decrease of the TLP amplitude, representing reversible reduction of pulpal blood flow, in young adult human teeth.