Structural and functional relations between the connective tissue and epithelium of enamel organ and their role during enamel maturation

Abstract

The morphological and possible functional interactions between the connective tissue and epithelial elements of enamel organ were examined during the maturation phase, using immunohistochemical techniques. Decalci ed mandibular sections (10µm) including incisors from Wistar rats ages 10-12 weeks were used. Sections were incubated with one or two primary antibodies targeting cell cytoskeleton (vimentin, α-actin, α-tubulin), dendritic marker (OX6), gap junctions (cx-43), enzymes (nitric-oxide synthase (nos1) and cyclooxygenase (cox1)), and ion transporters (Na + /H + exchanger (NHE1) and Na + /Ca 2+ exchanger (NCX)) for 24h, before incubation with the appropriate conjugated uorescent secondary antibodies. Sections were then examined by uorescence microscopy. Haematoxylin-eosin slides were also employed. Cellular heterogeneity and morphological modulations were identi ed within the epithelial and connective tissue elements of the enamel organ suggesting complex cellular interactions and indicating the use of enamel organ term to represent all these regions. Also, some ion transportation activity, and nos1 and cox1 signalling pathways have been identi ed, indicating intercellular communication between these regions. A hypothesis was suggested, to explain the morphological modulation of ameloblasts and papillary cells during enamel maturation aimed to increase the transporting membrane surface area to accomplish faster and bulker ion transportation to achieve controlled pH and to direct Ca 2+ towards enamel. Connective tissue covering epithelial cells of the enamel organ showed morphological and physiological interaction during enamel maturation, suggesting new functional concepts.

Cavity preparation model in rat maxillary first molars: A pilot study

“…For many years, animal models have been used in dental research (1,2) . Mainly to identify the effect of different stimuli on pulp tissue and host defense mechanism (3,4) . These models can provide an environment that mimics aspects of biological processes without the risk of harming a human.…”