Measurement of enamel remineralization using microradiography and confocal microscopy. A correlational study.
Tooth minerals are lost and regained constantly in a normal, human oral environment. Different methods have been developed to measure this gain and loss in enamel minerals; however, these methods deal with different problems, such as being time consuming or involving the use of X-rays. The aim of this study was to determine if remineralization measured in a thin enamel section (TS) by transversal microradiography (MR) can be reliably monitored by measuring lesion parameters (area, total and average dye fluorescence) on the same TS or on half a tooth (HT) with confocal laser scanning microscopy (CLSM). Thirty-six human enamel specimens were demineralized for 96h, and then half of each specimen was covered with an acid-resistant nail varnish. Specimens were divided into three groups (12/group) and subjected for 20 days to a cyclic remineralization regimen with consisted daily of a 4-hour acid challenge, four 1-min treatment periods with 0, 250 or 1,100 ppm F dentifrice slurries (1:2; dentifrice:water) and 20 h in pooled, human saliva, at room temperature. Specimens were cut and analyzed by MR, then stained with a fluorescent dye (0.1mM rhodamine B) for 1 h and analyzed using CLSM. Both MR and CLSM detected significantly greater remineralization (p<0.05) in the specimens treated with the fluoride-containing dentifrices than in the specimens treated with 0 ppm F. Significant differences were detected between specimens treated witht the fluoride-containing dentifrices by MR and CLSM (HT area and total fluorescence). Statistically significant (p<0.05) Pearson correlation coefficients were calculated between the MR and CLSM data: difference in MR mineral content (DeltaM) versus HT lesion area = 0.71; DeltaM versus HT total fluorescence = 0.70; DeltaM versus HT average fluorescence = 0.61; DeltaM versus TS lesion area = 0.88; DeltaM versus TS total fluorescence = 0.63, and DeltaM versus TS average fluorescence = 0.40. It is concluded that confocal microscopy in either TS or HT may provide valid surrogates (area and total fluorescence) for MR measurements in enamel remineralization studies.
González-Cabezas
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Oral Health Research Institute, School of Dentistry, Indiana University, Indianapolis, Ind., USA. CHARLGONZ@IUSD.IUPUI.EDU
Fontana
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Dunipace
A J
AJ
Li
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Fischer
G M
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Proskin
H M
HM
Stookey
G K
GK
D000704:Analysis of Variance; D002327:Cariostatic Agents / Q000494:pharmacology; D003743:Dental Enamel / Q000737:chemistry* / Q000000981:diagnostic imaging / Q000648:ultrastructure; D003802:Dentifrices / Q000494:pharmacology; D005456:Fluorescent Dyes; D005459:Fluorides / Q000494:pharmacology; D006801:Humans; D008852:Microradiography; D018613:Microscopy, Confocal; D008903:Minerals / Q000032:analysis*; D010919:Placebos; D015203:Reproducibility of Results; D012235:Rhodamines; D012463:Saliva / Q000502:physiology; D017001:Tooth Demineralization / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D014089:Tooth Remineralization
D002327:Cariostatic Agents; D003802:Dentifrices; D005456:Fluorescent Dyes; D008903:Minerals; D010919:Placebos; D012235:Rhodamines; D005459:Fluorides