Histological processing of teeth and periodontal tissues for light microscopy analysis.

It is possible to obtain histological preparation of teeth and periodontium with satisfactory levels of quality by means of routine histological techniques, since specific cares are implemented during the sample processing. The formation of access ducts for the quick penetration of the fixative solution, the complete removal of the demineralizing agent and the increase of the time of dehydration, clearing, and paraffin embedding are some of these cares. A variety of fixing and demineralizing solutions have been proposed in the literature for teeth and periodontium processing. The author's' experience along the years demonstrated the possibility of satisfactory results with 10% buffered neutral formalin as fixative solution and 10% pH 7.3 EDTA as demineralizing solution. Sections of 6 μm in thickness obtained from paraffin-embedded samples, stained with hematoxylin and eosin, comply with the most morphological and morphometric evaluations. Besides, this routine protocol allows the use of serial sectioning for more specific techniques such as histochemical and immunohistochemical analyses, which are suitable for cellular constituent and extracellular matrix evaluation of teeth and periodontium. For the study of mineralized phases of isolated human teeth, ground sections can be obtained by the cutting-grinding technique. Though it is a recognized method of study, there are some technical difficulties involved, which are little exploited in the literature. This chapter presents a detailed cutting-grinding protocol for the histological evaluation of undecalcified isolated teeth and routine histology, which can be easily reproduced in any research or teaching support laboratory.