Dnj. Ricketts et al., HISTOLOGICAL VALIDATION OF ELECTRICAL-RESISTANCE MEASUREMENTS IN THE DIAGNOSIS OF OCCLUSAL CARIES, Caries research, 30(2), 1996, pp. 148-155
Diagnosis of occlusal caries is difficult from visual and radiographic
examination. The use of electrical resistance measurement has been de
scribed previously and reported to be a potentially sensitive alternat
ive technique. This is possibly due to the decreased resistance of car
ious pits and fissures. The aim of this study was to validate a protot
ype electrical caries monitor for the diagnosis of caries in pits and
fissures in vitro using a microfocal radiographic technique. Thirty di
screte sites were investigated in 10 extracted molar teeth. Electrical
resistance measurements were recorded at each site and thick sections
(approximately 0.65 mm) prepared for microfocal radiography. Microfoc
al radiography indicated that six sites were sound, 10 had enamel cari
es and 14 dentine caries. At a resistance value of 2.2 M Omega, below
which a site was regarded as carious and above which it was regarded a
s sound, electrical resistance measurements proved sensitive (92%) and
specific (100%). Quantification of mineral content indicated that min
eral loss in enamel may influence resistance measurement more than les
ion depth.