Yl. Ie et al., ELECTRICAL CONDUCTANCE OF FISSURE ENAMEL IN RECENTLY ERUPTED MOLAR TEETH AS RELATED TO CARIES STATUS, Caries research, 29(2), 1995, pp. 94-99
Pit-and-fissure caries lesions contribute greatly to the caries incide
nce in permanent molar teeth in children. To date, the diagnosis of oc
clusal caries is still performed mainly by visual inspection, periodic
ally aided by bite-wing radiography However, in detecting small occlus
al carious lesions, these methods perform inadequately, especially in
low caries prevalence populations or individuals. The use of electrica
l conductance measurements (ECMs) has been evaluated to improve the di
agnosis of small occlusal carious lesions. The aim of this study was t
o monitor the electrical conductance of fissure enamel in recently eru
pted molar teeth and to relate these measurements to the caries status
. 50 children aged 5-15 years, having first or second permanent molars
that were not exposed to the oral environment for more than 6 months,
participated in the study. The diagnostic systems evaluated were visu
al inspection and ECMs. Following baseline data recording, diagnostic
measurements were repeated three times within 18 months. Data were col
lected at predefined sites in the fissures. 18 months after baseline r
ecording, 179 sites at 60 molar teeth in 27 children were judged to re
quire a sealant based on visual inspection. After removal of carious t
issue, two examiners jointly decided on the status of decay as per the
criteria: O = no caries or caries limited to enamel, and 1 = caries i
nvolving dentine. The sensitivity of ECM continued to increase with ti
me after a slight initial dip, whereas the specificity continuously in
creased after baseline measurements as a result of the decreasing amou
nt of false-positive diagnoses. ECMs obtained after each 6-month inter
val from sites that developed caries were significantly higher than th
ose from sites that remained caries free (all p < 0.02). Furthermore,
ECMs obtained from sites that exhibited dentinal caries upon validatio
n were significantly higher than those obtained from sites that showed
no caries or caries limited to enamel on validation (p < 0.001). The
areas under the receiver operating characteristic curves of visual ins
pection and ECMs were 0.67 and 0.77, respectively, a difference that w
as not statistically significant (p > 0.05). It was concluded from thi
s study that ECMs can aid the detection of fissure caries in recently
erupted molar teeth. The results imply that an ECM value of 6.5 can be
considered as the cut-off between no caries or caries limited to enam
el and dentinal caries. Furthermore, ECMs can be used to predict the p
robability that a sealant or a sealant restoration will be required wi
thin 18-24 months after eruption.