| Project/Area Number |
10671929
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
矯正・小児・社会系歯学
|
|---|
| Research Institution | Tokyo Medical and Dental University |
|---|
Principal Investigator |
MIWA Zenzo TOKYO MEDICAL AND DENTAL UNIVERSITY, FACULTY OF DENTISTRY, LECTURER, 歯学部・付属病院, 講師 (30157705)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
IIJIMA Hideyo TOKYO MEDICAL AND DENTAL UNIVERSITY, FACULTY OF DENTISTRY, ASSISTANT PROFESSOR, 歯学部・付属病院, 助手 (00184341)
|
|---|
| Project Period (FY) |
1998 – 1999
|
| Project Status |
Completed (Fiscal Year 1999)
|
| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1999: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1998: ¥2,400,000 (Direct Cost: ¥2,400,000)
|
|---|
| Keywords | Transmitted-light photoplethysmography / Young permanent teeth / Pulpal haemodynamics / Traumatized teeth / 乳歯 / 幼若永久歯 / 発光ダイオード / 外傷歯 |
|---|
| Research Abstract |
In this study, we succeeded to record transmitted-light photoplethysmography (TLP) from the dental pulp in young humans and examined its applicability to pulp vitality test. Upper central incisors of one adult and six children were used for this investigation. A resin cap of the examined tooth was prepared on the plaster model of the subjects' upper arch. A green light-emitting diode( LED, peak power at 525nm) illuminated the palatal surface of the examined tooth via an optical fiber attached to the individual resin cap, and the transmitted-light through the pulp was picked up from the labial surface of the tooth. The intensity of the transmitted-light was guided to a CdS photoconductive cell (peak sensitivity at 550nm), and its intensity change was recorded as TLP through AC-coupled amplifier together with the finger plethysmography of the subjects. Recordings were made with and without opaque black rubber dam application in a dark room. In one subject, 2% lidocaine solution containing 1/80,000 epinephrine was periapically infiltrated and the transition of the amplitude of the TLP was observed. Results obtained were as follows : 1) TLP, synchronous with the finger plethysmography, was recognized from sound permanent teeth of an adult and the young subjects. The signal amplitude of the TLP was larger and the waveform was much more clearer with the young subjects. 2) TLP was slightly recorded from luxated teeth which did not respond to electrical stimulation to the pulp. But with an implanted tooth no obvious pulse wave was detected. 3) The dam application did not produce a significant signal reduction. 4) Periapical infiltration of 2%LE produced a gradual decrease of the amplitude of TLP and then was followed by an increase. Results indicated that TLP is considered to reflect pulpal haemodynamics and this system would be useful for the diagnosis of pulpal vitality of the young permanent teeth without eliciting any pain sensation.
|
