X-ray microtomography: a novel technique for the quantification of effects in enamel following CO2 laser application

X-ray microtomography (XMT) is a miniaturised version of the technique of computer axial tomography as used in medical diagnosis. As an example of the dental research applications of the technique, a pilot study is described in which the effects of a continuous wave carbon-dioxide laser on dental enamel are investigated and the use of XMT for the non-invasive measurement of mineral density changes within dental hard tissues is demonstrated. The results show clearly the ability of XMT to display graphically, and to quantify, changes in mineral density occurring within lased specimens, compared with a conventional SEM view of similar material. There have been many reports of the problems found when using lasers to cut dental hard tissues, and this paper demonstrates that XMT is of particular value in the study of the cracking induced by many lasers. We also suggest that XMT might be used in many studies investigating mineral density changes within dental hard tissues.