Volume 8, Number 6     November/December 2000

Easing the Pain of Periodontal Disease

With the patient reclining in the chair, the dentist pokes a small metal probe into the space between the teeth and the gums, searching for evidence of periodontal disease. Conventional periodontal probing is invasive, very uncomfortable for the patient, and the results can vary greatly, both for different dentists and for repeated measurements by the same dentist. But this painful, archaic method may be destined for the archives of dental history, thanks to the development of an ultrasonagraphic probe (USProbe).

The Ultrasonagraphic Probe provides a mapping system for non-invasively making and recording differential measurements of the depth of any patient's periodontal ligaments, leading to earlier diagnoses of periodontal disease. Photo provided by NASA Langley Research Center.

Periodontal disease is the most common dental disease, involving the loss of teeth by the gradual destruction of ligaments that hold teeth in their sockets in the jawbone. The disease usually results from an increased concentration of bacteria in the pocket, or sulcus, between the gums and teeth. These bacteria produce acids and other byproducts, which enlarge the sulcus by eroding the gums and the periodontal ligaments.

The sulcus normally has a depth of one to two millimeters, but in patients with early stages of periodontal disease, it will have a depth of three to five millimeters. By measuring the depth of the sulcus, periodontists can have a good measure of the disease's progress. Presently, there are no reliable clinical indicators of periodontal disease activity and the best available diagnostic aid, periodontal probing, is only an analysis of what attachment is already lost. A method for detecting small increments of periodontal ligament breakdown would permit earlier diagnosis and intervention with less costly and time-consuming therapy, while overcoming the problems associated with conventional probing.

The USProbe provides a mapping system for non-invasively making and recording differential measurements of the depth of any patient's periodontal ligaments relative to a fixed point, the boundary between the root's crown and its root (called the CEJ). The mapping system uses ultrasound to detect the top of the ligaments at various points around each tooth, and uses either ultrasound or an optical method to find the CEJ at the same points. The depth of the sulcus is calculated as the difference between these two points.

The current method of diagnosing periodontal disease is invasive, uncomfortable and inexact, requiring that a small metal probe be poked into the space between the teeth and the gums. Photo provided by NASA Langley Research Center.

According to John Senn, co-owner of Visual Programs, Inc., the new device may some day be celebrated as one of the major steps forward in the battle against periodontal disease.

"The probe should be the next major piece of dental equipment. By using the new technology, dentists and hygienists will be able to perform exams earlier and may detect periodontal disease while the teeth can still be saved," he added.

The probe that is used in the mouth to send and receive ultrasound signals is very small. Additional instrumentation is contained within a standard personal computer, allowing the entire measurement to be computerized. In addition, manual charting of pocket depth will be eliminated since the data will be automatically transmitted to the computer.

In addition to solving the problems associated with conventional probing, USProbe may also provide information on the condition of the gum tissue and the quality and extent of the bond to the tooth surface.

The roots for the ultrasound technology used in this innovation are in an ultrasound-based time-of-flight technique used routinely in NASA Langley Research Center's Non-Destructive Evaluation Sciences Laboratory to measure material thickness and, in some cases, length. The primary applications of that technology have been aircraft skin thickness for corrosion detection and bolt length for bolt tension measurements.

The Periodontal Structures Mapping System was invented at NASA Langley Research Center by John A. Companion under the supervision of Dr. Joseph S. Heyman. Support of the research and development that led to this invention was provided by NASA's Technology Applications Engineering Program and by the U.S. Navy's Dental School, Great Lakes, Illinois. This technology was patented in May 1998 and the patent was exclusively licensed to Visual Programs, Inc. of Richmond, Virginia, in January 2000. Under their sponsorship and a grant from the NIH Institute of Dental and Craniofacial Research, professors and graduate students in the College of William and Mary's Applied Sciences Department are developing a commercial product based on the NASA invention. This effort is being supported by hygienists at Old Dominion University's School of Dental Hygiene in Norfolk, Virginia.

For more information on the USProbe, please contact Mr. John Senn of Visual Programs, Inc., Richmond, Virginia. Call: 804/553-3157,
E-mail: jsenn@tooth.net Please mention you read about it in Innovation.

Credits