Molecular biology behind how enamel can be regenerated using the science of biomimicry.

1. ENAMEL BIOMIMETICS
THE BIRTH OF REGENERATIVE DENTISTRY
Registration No. 449

2. What is Biomimetics?
and how it can alter dentistry forever.
Biomimetics is the science of emulating nature’s best
biological ideas and implying them to satiate human needs.

3. The Foundation of Enamel Biomimetics
• The aim is to mimic the rod and inter-
rod structure of enamel composing of
Inorganic hydroxyapatite (HAP): 96%
organic proteins & water: 4%
• To regenerate amelogenin cell lines
which were lost during maturation
phase of amelogenesis.
• To rebuild a sound structure that
resembles the keyhole pattern or
interprismatic structure of the crystal
apatite rods.
Rod & interrod structure of enamel (Transverse and vertical section)

4. Fate of ameloblasts & its secretory products during amelogenesis.
• Ameloblasts mature and produce a distal
extension known as the Tome’s process
during the secretory phase which
produces the rod & inter-rod structure of
enamel.
• During maturation phase, 25% of
ameloblasts undergo degeneration hence,
losing the ability to regenerate enamel
forever.
• Since ameloblasts cannot be regenerated
naturally, enamel inductive techniques
were introduced.

5. The Physico-chemical approach of enamel synthesis:
• Involves in-vitro induction of
Hydroxyapatite crystals using
Amorphous Calcium phosphate (ACP)
as a precursor.
• ACP nanocomposite helps in
remineralization and preservation of
enamel but is of metastable nature.
• To stabilize ACP, carboxymethyl
chitosan (CMC) was used along with
Alendronic acid to generate CMC-ACP
nanoparticles.

6. Bio-inspired enamel HEALING!
(Peptide based enamel surface remineralization)
The peptide-enabled technology allows the deposition of 10 to 50 micrometers
of new enamel on the teeth after each use.

7. Biomimetic system based on Amelogenin-inspired dendrimers
(Alendronate-based PAMAM dendrimers)
• Alendronate-conjugated PAMAM dendrimer (ALN-PAMAM-COOH) could induce In-
situ remineralization of tooth enamel, attributed to the combined effect of the HA-
anchored property of the ALN moiety and the remineralization capability of the –COOH
moiety.
• The newly formed crystals had nanorod-like structure similar to that of human tooth
enamel.

8. Regenerating enamel via Phosphate-terminated dendrimer
(PAMAM-PO3H2)
• Phosphate-terminated dendrimer
(PAMAM-PO3H2) was synthesized
and assessed for the ability to
remineralize acid-etched human tooth
enamel.
• After being incubated in artificial
saliva for 3 weeks, a newly generated
HAP layer of 11.23 µm thickness
was found on acid-etched tooth
enamel treated with PAMAM-PO3-
H2.

9. Enamel engineering using MMP 20 in CS-AMEL hydrogel
• Recombinant human MMP-20 was added to the CS-AMEL hydrogel to cleave full-length
amelogenin during the growth of enamel-like crystals on an etched enamel surface.
• The newly grown crystals in the sample treated with the hydrogel showed more uniform
orientation and greater crystallinity than the samples treated with CS-AMEL hydrogel
without MMP-20.
• As a result, both the modulus and hardness of the repaired enamel were significantly
increased by the MMP-20–CS-AMEL hydrogel.As a result, both the modulus and
hardness of the repaired enamel were significantly increased (1.8- and 2.4-fold,
respectively) by the hydrogel.

10. Microstructure of enamel-like apatite crystals in the newly grown layer.
Scanning electron microscopy (SEM) images showing
(A, B)Etched enamel,
(C, D)Newly grown hydroxyapatite crystals in CS,
(E, F)AMEL-CS hydrogel,
(G, H)AMEL-CS-MMP-20.
Arrows in D, H and F indicate the crystal orientation.
A comparitive overview of enamel generated based on
types of biomimetic systems

11. Synthetic enamel- vangaurd of the tooth?
 The polypeptide-based synthetic
enamel reveals,
• Excellent mechanical properties,
which are highly close to those of
original natural enamel.
• High chemical stability against acid
erosion.
• Seamless structural resemblence with
the natural enamel crystal structure.
A graphical comparision between natural and regenerated
(polypeptide based) enamel.

12. THANKYOU FOR YOUR ATTENTION.

13. References:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6320371/
https://pubmed.ncbi.nlm.nih.gov/28113034/
https://pubmed.ncbi.nlm.nih.gov/7548623/
https://pubmed.ncbi.nlm.nih.gov/21081224/
https://www.sciencedirect.com/science/article/abs/pii/S1742706114002190
https://www.sciencedirect.com/science/article/pii/S0014305719303027
https://www.semanticscholar.org/paper/The-Presence-of-MMP-20-Reinforces-Biomimetic-Enamel-
Prajapati-Ruan/6088daa0748b11f535df2f42fb2c7c0f46a0951d