Longitudinal Microradiography

Longitudinal Micro Radiography (LMR) is a method to determine mineral loss in tooth slice samples in vitro. Although replaced by QLF™ InVitro by now, the method is presented here for archeological purposes. In this method a microradiogram of a slice of a tooth is prepared. Mineral content is then computed by performing measurements of the optical density of the microradiogram and comparing these values with that of a aluminium step wedge. LMR is based on the same principle as TMR . In contrast to TMR, where a transversal slice of the tooth is created, LMR is based on longitudinal slices. The IRS LMR system is highly automated. Scanning of the sample is performed using a XY scanning table and all calculations are performed automatically. A microradiogram measurement setup is shown on the right.

Below a 3D-plot is made of the change in mineral content (z-axis) versus position on the surface at several moments in time.


0 sec	95 sec

185 sec	355 sec

More information

LMR has become obsolete with the emergence of QLF™. With QLF™ InVitro, the same longitudinal monitoring of demineralizing surfaces is possible as with LMR, but infinitely quicker and easier. LMR is therefore not available anymore.

LMR References

LMR technique

de Josselin de Jong E, van der Linden AH, Borsboom PC, ten Bosch JJ. Determination of mineral changes in human dental enamel by longitudinal microradiography and scanning optical monitoring and their correlation with chemical analysis. Caries Res. 1988;22:153-159.
de Josselin de Jong E, van der Linden AH, ten Bosch JJ. Longitudinal microradiography: a non-destructive automated quantitative method to follow mineral changes in mineralised tissue slices. Phys Med Biol. 1987;32:1209-1220. LMR as validation method
Emami Z, al-Khateeb S, de Josselin de Jong E, Sundstrom F, Trollsas K, Angmar-Mansson B. Mineral loss in incipient caries lesions quantified with laser fluorescence and longitudinal microradiography. A methodologic study. Acta Odontol Scand. 1996;54:8-13.
Hafstrom-Bjorkman U, Sundstrom F, de Josselin de Jong E, Oliveby A, Angmar-Mansson B. Comparison of laser fluorescence and longitudinal microradiography for quantitative assessment of in vitro enamel caries. Caries Res. 1992;26:241-247.
Van de Rijke JW, Ten Bosch JJ. Optical quantification of caries-like lesions in vitro by use of a fluorescent dye. J Dent Res. 1990;69:1184-1187.
van de Rijke JW, Pos N, ten Bosch JJ. A model study for quantification of approximal caries with a fluorescent dye. Caries Res. 1990;24:436-440.

Use of LMR in de- and remineralisation studies

Herkstroter FM, Witjes M, Arends J. Demineralization of human dentine compared with enamel in a pH-cycling apparatus with a constant composition during de- and remineralization periods. Caries Res. 1991;25(5):317-322.
Zuidgeest TG, Herkstroter FM, Arends J. Mineral density and mineral loss after demineralization at various locations in human root dentine. A longitudinal microradiographic study. Caries Res. 1990;24(3):159-163.
Jansma J, Vissink A, 's-Gravenmade EJ, Visch LL, Fidler V, Retief DH. In vivo study on the prevention of postradiation caries. Caries Res. 1989;23:172-178.
Jansma J, Vissink A, 's-Gravenmade EJ, de Josselin de Jong E, Jongebloed WL, Retief DH. A model to investigate xerostomia-related dental caries. Caries Res. 1988;22(6):357-361. Wavelength-Independent Microradiography
Herkstroter FM, Noordmans J, Ten Bosch JJ. Wavelength-independent microradiography used for quantification of mineral changes in thin enamel and dentin samples with natural surfaces, pseudo-thick tooth sections, and whole teeth. J Dent Res. 1990 Dec;69(12):1824-1827.
Herkstroter FM, Ten Bosch JJ. Wavelength-independent microradiography: a method for non-destructive quantification of enamel and dentin mineral concentrations using polychromatic x-rays. J Dent Res. 1990 Aug;69(8):1522-1526.