Related Experiment Video
Updated: Dec 10, 2025

Micro-dissection of Enamel Organ from Mandibular Incisor of Rats Exposed to Environmental Toxicants
Published on: March 29, 2018
Structural and chemical enamel characteristics of hypomineralised second primary molars
E Alifakioti1, A Arhakis2, S Oikonomidis3
1Department of Paediatric Dentistry, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece. alifakioti.evgenia@gmail.com.
Purpose:
Although hypomineralised second primary molars (HSPM) are considered belonging in the same entity as molar incisor hypomineralisation (MIH), the structure and chemistry of their defected enamel have not been described. We aimed to study these in justifying any similarities with MIH.
Methods:
Nine HSPM and five first permanent molars with MIH were either fractured or sectioned longitudinally through their defective enamel and examined by scanning electron microscopy. Relative amounts of calcium (Ca), phosphorus (P), oxygen (O), carbon (C) and the Ca:P ratio were calculated in the primary molar samples by energy -dispersive spectrometry.
Results:
Rod width was deficient in the defected enamel of HSPM resulting in wide interrod spaces and suggesting similarities to permanent enamel structure in MIH. In areas with breakdown, cracks and disrupted coherence between enamel rods were more marked. Differences in Ca, P, O, C and Ca:P ratio between hypomineralised and sound enamel in HSPM followed the same trend as in MIH without reaching statistical significance.
Conclusion:
Marked structural differences between sound and hypomineralised enamel of HSPM and similarity to MIH enamel were verified.
Related Concept Videos
Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or...
Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin...
Essential Minerals for Bone Health
Calcium and Phosphorus
Calcium is a critical component of bones, especially in the form of calcium phosphate and calcium carbonate. Since the body cannot make calcium, it must be obtained from the diet. However, calcium cannot be absorbed from the small intestine without...
The Bone Matrix

