Richard W Webber

US Patent:

48362069, Jun 6, 1989

Filed:

Feb 25, 1987

Appl. No.:

7/019185

Inventors:

G. Maret Maxwell - Wheaton MD
Richard L. Webber - Myersville MD

Assignee:

The United States of America as represented by the Department of Health
and Human Services - Washington DC

International Classification:

A61B 500

US Classification:

128633

Abstract:

An optical technique and device for assessing tooth vitality, involving the use of trans-illumination to detect differentially the relative absence of light absorbed by hemoglobin in circulating blood inside a healthy tooth. White light received from an illuminated healthy tooth is relatively devoid of intensity at a wavelength characteristic of absorption by hemoglobin, when compared with light following the same path in the tooth but of a longer wavelength, by taking the ratio of intensities of the two wavelengths the light of one wavelength is relatively more absorbed by hemoglobin or oxyhemoglobin than the other, indicating the relative amount of blood or oxygen in the blood present in the tooth at the time of the measurement. A broad-spectrum light source is rigidly coupled to a split-beam, differentially-filtered photometer incorporating relatively narrow band filters. Vitality is assessed from the ratio of the scattered light at the two wavelengths, and in change of this ratio overtime.