[The effect of the magnification ratio on 2 methods of computerized image analysis in scanning electron microscopy].

The aim of this study is to compare two computerized analysis methods of SEM dentinal walls views. The first technic is an indirect one using a primary marking and a secondary measurement. The second one is a direct threshold analyse, using the grey levels selection. The influence of the magnification is analysed in a second part. The first technic is considered as a reference one. The results show that the threshold measurement technic is only reliable at a high magnification. A direct surface measurement cannot be used at a low magnification. A pretreatment could enhance the ability of a computer to measure the areas covered with smear-layer or organic debris on SEM micrographs.