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Ultrastructural preservation of rat embryonic dental tissues after rapid fixation and dehydration under microwave irradiation
Author(s) -
Massa Luciana F.,
AranaChavez Victor E.
Publication year - 2000
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1034/j.1600-0722.2000.00753.x
Subject(s) - odontoblast , glutaraldehyde , ultrastructure , endoplasmic reticulum , chemistry , matrix (chemical analysis) , vesicle , golgi apparatus , electron microscope , ameloblast , fixative , fixation (population genetics) , anatomy , enamel paint , biophysics , materials science , cytoplasm , membrane , dentin , biochemistry , biology , chromatography , composite material , physics , gene , optics
Adequate preservation of the cells and matrix of mineralising tissues remains difficult, as organic components and initial mineral deposits may be lost during conventional processing for electron microscopy. In this study, we have reduced significantly the processing time using microwave irradiation. Rat molar tooth germs were fixed in 4% glutaraldehyde+4% formaldehyde with 0.1 M sodium cacodylate in a laboratory microwave oven for two periods of 20 s with a maximal temperature of 37°C. After conventional washing and post‐fixation, specimens were dehydrated in graded ethanols under microwave irradiation for a total of 7 min 20 s. For comparison, some specimens were processed by conventional methods. After embedding, ultrathin sections were examined by electron microscopy. In differentiating ameloblasts and odontoblasts, plasma membranes, mitochondria, rough endoplasmic reticulum, the Golgi complex, together with all other cytoplasmic organelles exhibited excellent preservation. Microtubules, microfilaments and coated vesicles were particularly evident. Crystal‐like mineral deposits were conspicuously present in relation to dentine matrix vesicles and collagen fibrils as well as in enamel matrix. The matrix of forming enamel had a globular electron‐lucent appearance. It is concluded that this is a rapid method which provides a preserved or even improved morphology.