University of Zagreb. School of Dental Medicine. Department of Oral Medicine.
Abstract
Električna impedancija (EI) je otpor prolasku izmjenične električne struje kroz tkivo. EI ovisi
o promjenama strukture i kemijskom sastavu tkiva, te se stoga koristi u dijagnostičke svrhe,
ponajprije kožnih promjena. Primjena EI za dijagnostiku na oralnoj sluznici nije dovoljno
znanstveno evaluirana.
Svrha rada bila je utvrditi referentne vrijednosti EI na zdravoj oralnoj sluznici, te evaluirati
izvedivost i ponovljivost metode. Svrha rada je također bila utvrditi utjecaj demografskih i
kliničkih faktora (spol, dob, pušenje, količina sline, pritisak elektrode) na vrijednosti EI.
U istraživanju je sudjelovao 101 ispitanik. Ispitanici su bili podijeljeni u tri skupine: 20-40
godina, 40-60 godina i preko 60 godina. Vrijednosti EI mjerene su posebno konstruiranim
uređajem tri puta u razmaku od po tjedan dana na 14 mjernih točaka u usnoj šupljini (po 7
točaka na lijevoj i desnoj strani).
Najviše vrijednosti EI zabilježene su na sluznici tvrdog nepca, a najniže na dorzumu jezika.
Nisu utvrđene statistički značajne razlike u vrijednostima EI između lijeve i desne strane.
Vrijednosti EI smanjivale su se s dobi ispitanika. Vrijednosti EI u žena bile su značajno više
nego u muškaraca. Nepušači su imali statistički značajno više vrijednost EI samo na sluznici
gornje usne. Količina sline nije imala utjecaja na izmjerene vrijednosti. Pritisak elektrode na
sluznicu utječe na izmjerene vrijednosti-primjenom višeg podtlaka izmjerene su statistički
značajno niže vrijednosti. Nisu utvrđene statistički značajne razlike između pojedinih
mjerenja kod svakog ispitanika.
Primjenom opisane metode moguće je izmjeriti vrijednosti EI na svakoj točki oralne sluznice.
Metoda je jednostavna i lako primjenjiva, te daje ponovljive i stabilne rezultate.Electrical impedance (EI) is the resistance to the flow of alternating electric current through a
tissue. It is dependent on the structure and the chemical composition of the tissue and is
therefore used for diagnostic purposes, primarily for changes in the skin. Application of EI in
diagnostics related to the oral mucosa has not been sufficiently evaluated scientifically.
The purpose of the study was to determine the reference values of EI on healthy oral mucosa,
and to evaluate the feasibility and reproducibility of the method. The aim also was to
determine the effect of demographic and clinical factors (gender, age, smoking, amount of
saliva, pressure of the electrode) on EI values.
The study included 101 subjects divided into three groups: 20-40 years, 40-60 years and over
60 years. Inclusion criteria were clinically normal oral mucosa and the ability to read and
understand the text of the informed consent. EI values were measured by a specially designed
device three times at one-week intervals at 14 measuring points in the oral cavity (7 points on
its left and right side, respectively). The intraoral sensor consisted of a system of concentric
electrodes that adhered to the mucous membrane through application of varying degrees of
negative pressure (250° or 350 MB). It was connected to the measuring device NI USB-6251
(National Instruments®, Austin, USA) connected via USB to a laptop. The measurement
programme developed on the basis of the LabView 8.5.1. software package (National
Instruments®, Austin USA) converted the electrical impulses from the device into digital
records and stored them in the database. Statistical analysis was performed using the SPSS
ver. 20 software (IBM Inc, USA).
The highest values of EI were recorded on the mucosa of the hard palate, and the lowest on
the dorsum of the tongue. No statistically significant differences in EI values between the left
and right side were established. EI values were found to decrease with age, and to be
significantly higher in women than in men. This finding needs to be verified and clarified in
future research. In nonsmokers, significantly higher EI values were found only in the mucosa
of the upper lip. The amount of saliva had no effect on the measured values. The pressure
exerted on the mucous membrane by the electrode did affect the measured values - applying
higher negative pressure resulted in statistically significantly lower values. No statistically
significant differences were found between individual measurements in any of the subjects.
The method described in the study makes it possible to measure EI values at each point of the
oral mucosa. The method is simple and easily applicable, and provides reproducible and
stable results, which in turn opens the possibility of using it for non-invasive differentiation of
healthy oral mucosa from various pathological conditions