This document discusses various theories of mineralization in hard tissues. It describes how mineralization occurs through matrix vesicles, collagen fibrils acting as nucleation sites, and the role of alkaline phosphatase. Matrix vesicles accumulate calcium and phosphate ions, forming the initial hydroxyapatite crystals which then fuse with others. Collagen fibrils provide gaps and pores for heterogeneous nucleation of crystals to begin. Alkaline phosphatase increases local phosphate concentration to promote further crystal growth. Overall, the document provides an overview of the cellular processes and molecular mechanisms involved in biomineralization of tissues like bone and teeth.
Amelogenesis is the formation of enamel. During amelogenesis, the ameloblast (enamel-forming cells) undergo various stages i.e the life cycle of ameloblast.
For more content check out my blog: www.rkharitha.wordpress.com "a little about everything dental"
I prepared this presentation during the first year of my MDS. This will give you a basic idea and necessary information about the pulp of the teeth and its histology. Hope you guys find it useful.
PHYSICAL PROPERTIES
CHEMICAL PROPERTIES
STRUCTURE OF ENAMEL
DEVELOPMENT OF ENAMEL
EPITHELIAL ENAMEL ORGAN
AMELOGENESIS
LIFE CYCLE OF AMELOBLASTS
AGE CHANGES IN ENAMEL
DEFECTS OF AMELOGENESIS
CLINICAL IMPLICATIONS
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Coronal and radicular pulp
Apical foramen
Accessory canal
Functions of dental pulp
Components of dental pulp
Functions of pulpal extracellular matrix
Organization of cells in the pulp
The principle cells of the pulp
The pathways of collagen synthesis
Matrix and ground substances
Vasculature and lymphatic supply
Innervation of Dentin- pulp complex
Disorders of the dental pulp
Advances in pulp vitality testing
Amelogenesis is the formation of enamel. During amelogenesis, the ameloblast (enamel-forming cells) undergo various stages i.e the life cycle of ameloblast.
For more content check out my blog: www.rkharitha.wordpress.com "a little about everything dental"
I prepared this presentation during the first year of my MDS. This will give you a basic idea and necessary information about the pulp of the teeth and its histology. Hope you guys find it useful.
PHYSICAL PROPERTIES
CHEMICAL PROPERTIES
STRUCTURE OF ENAMEL
DEVELOPMENT OF ENAMEL
EPITHELIAL ENAMEL ORGAN
AMELOGENESIS
LIFE CYCLE OF AMELOBLASTS
AGE CHANGES IN ENAMEL
DEFECTS OF AMELOGENESIS
CLINICAL IMPLICATIONS
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Coronal and radicular pulp
Apical foramen
Accessory canal
Functions of dental pulp
Components of dental pulp
Functions of pulpal extracellular matrix
Organization of cells in the pulp
The principle cells of the pulp
The pathways of collagen synthesis
Matrix and ground substances
Vasculature and lymphatic supply
Innervation of Dentin- pulp complex
Disorders of the dental pulp
Advances in pulp vitality testing
Mineralization (calcification) is the process of deposition of insoluble calcium salts in a tissue. It is one of the important steps in the formation of hard tissues of the body that is enamel, dentin, bone, and cementum. The synthetic cells, along with the help of the enzyme alkaline phosphatase, aid the mineralization process. The mineral content (inorganic portion) of all the hard tissues of the body is mainly in the form of Calcium hydroxyapatite crystals, Ca10(PO4)6(OH)2.
When calcium phosphate deposition is initiated, the crux is then to control spontaneous precipitation from tissue fluids supersaturated in calcium and phosphate ions and to limit it to well-defined sites. Formative cells achieve this by creating microenvironments that facilitate mineral ion handling and by secreting proteins that stabilize calcium and phosphate ions in body fluids and/or control their deposition onto a receptive extracellular matrix.
The synthetic cells achieve this property by secreting proteins that stabilize Calcium and Phosphate in the body fluids and control their deposition onto the extracellular matrix. These proteins are:
1. Salivary proteins
2. Enamel matrix protein
3. Dentin, cementum, and bone matrix proteins.
Calcium hydroxide cement / rotary endodontic courses by indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
Basavarajeeyam is an important text for ayurvedic physician belonging to andhra pradehs. It is a popular compendium in various parts of our country as well as in andhra pradesh. The content of the text was presented in sanskrit and telugu language (Bilingual). One of the most famous book in ayurvedic pharmaceutics and therapeutics. This book contains 25 chapters called as prakaranas. Many rasaoushadis were explained, pioneer of dhatu druti, nadi pareeksha, mutra pareeksha etc. Belongs to the period of 15-16 century. New diseases like upadamsha, phiranga rogas are explained.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
MANAGEMENT OF ATRIOVENTRICULAR CONDUCTION BLOCK.pdfJim Jacob Roy
Cardiac conduction defects can occur due to various causes.
Atrioventricular conduction blocks ( AV blocks ) are classified into 3 types.
This document describes the acute management of AV block.
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
4. HARD TISSUE
4
Mineralized and have firm intercellular
substances.
Includes bone, cementum, dentin and enamel
Except enamel , they are all
-Specialised connective tissue
-Collagen (esp. type 1) plays a role in
determining their structure.
HARD TISSUE FORMATION: Cells-production of
organic matrix-capable of accepting mineral +
activity of alkaline phosphatase + a good blood
supply prerequisites
5. FORMATIVE CELLS
5
Ability to synthesise and secret organic matrices of hard
tissues
Fibroblast
Odontoblast
Ameloblast
Cementoblast
Osteoblast
They all possess :
Abundant mitochondria
Golgi apparatus
Rough endoplasmic reticulum
Transport vesicles and secretory vesicles.
6. ORGANIC MATRIX
6
Collagenous proteins:
Type I collagen : It acts as scaffold that accumulate the
minerals in holes and pores of fibrils.
Non - collagenous proteins:
Proteoglycans
Phospholipids
Phosphoprotein
Non collagenous protiens are involved in mineralization of
enamel whereas in other hard tissues collagen play an
important role.
7. ORGANIC MATRIX OF
ENAMEL7
consist of a distinctive family of enamel proteins:
90% amelogenins
Proline, Histidine, Glutamine
- helps to maintain space between crystals.
10% non- amelogenins
Tuftelin, enamelin, amelin
-helps in nucleation and growth of crystals.
Nevertheless, all hard tissues regardless of their composition
are capable of accepting minerals in form of hydroxyapatite
crystals.
9. MINERALS
9
Inorganic component of mineralized tissue
Consist of mainly: calcium hydroxyapatite i.e a biological
apatite. Ca10(PO4)6(OH)2
Unit cell - least no. of Ca, phosphate and hydroxyl ions
able to establish a stable ionic relationship.
Shape-hexagonal
Unit cells stacked together - lattice of crystal
Various size – number of repetition of this arrangement
HA crystal in mesenchymal hard tissue:100*200*50*50A
HA crystal in enamel: length – 1400A ; width – 800A
10. BIOLOGICAL APATITE
10
Biological apatite is built on a definite ionic lattice pattern that
permits considerable variation in its composition through
substitution, exchange and adsorption of ions.
In general,
Shape of apatite crystals – needle like or platelike.
Shape of apatite crystals in enamel – long, thin ribbons.
Each apatite crystal has 3 surfaces:
Crystal interior
Crystal surface
Hydration shell
All of 3 surfaces are available for exchange of ions.
11. CONTD..
11
Exchange of ions can take place between:
Mg & Na can substitute Ca position
F and Cl can substitute hydroxyl position
Carbonate in both hydroxyl & phosphate position.
F substitution decrease the solubility of crystallites
whereas carbonate increase.
Mg inhibits crystal growth.
Adsorption of ions - electrostatic attraction or bound in
hydration layer.
The apatite crystal is able to retain its structural
configuration while accomodating these substitution.
12. 12
Deposition of mineral salts in an around organic
matrix to make it a calcified structure.
Although , tissue fluid is supersaturated with Ca & P
ion , spontaneous precipitation of calcium phosphate
does not take place.
BECAUSE:
Inhibitory macromolecules-inhibit crystal formation.
Unstable-initial cluster of ions needed to form a lattice
structure
Furthermore, the formation of clusters of ions
requires the expenditure of energy and an energy
barrier must be overcome for crystallization.
MINERALIZATION
13. CONTD..
13
When deposition is initiated, the crux is then to:
Control spontaneous precipitation from tissue
fluids
Limit it to well defined sites
This function is done by formative cells by:
Creating microenvironment facilitating mineral ion
handling
Secreting proteins that stabilizes Ca & P ions in
body fluids
Controlling Ca & P ions deposition on to ECM.
14. NUCLEATION
14
HOMOGENOUS NUCLEATION :
Any local increase in concentration of
inorganic ions permits a sufficient no. of ionic
clusters & crystallite to form.
HETEROGENOUS NUCLEATION:
The presence of nucleating substance allows
crystal formation to occur, in absence of a locally
increased ionic concentration.
15. MECHANISM OF
MINERALIZATION15
For initiation:
1. Matrix vesicle
2. Heterogeneous nucleation/Collagen
mineralization
For continuation:
1. Collagen growth
2. Secondary nucleation
16. 1.MATRIX VESICLES
16
Small membrane bound structure lying free in the matrix
Size= 25-250nm in diameter
Rounded outgrowth of cell membrane , buds off from
osteoblasts,chondrocytes and odontoblasts
Exist only in relation to initial mineralisation
Form an independent unit within the first form organic matrix.
Rich in phospholipids(esp. phophotidyl serine)-high affinity for
Ca ions.
A site for Ca and Pi accumulation by deposition of initial
mineral complex (i.e. nucleation) occurs & hydroxyapatite is
produced.
Annexins in vesicles form a Ca channel thus incorporating
ions.
17. CONTD..
17
Alk. phosphatase , pyrophosphatase, Ca ATPase, metalloproteinases,
proteoglycans & anionic phospholipids bind Ca & P ions
Calcium inorganic phosphate phospholipids complex
Initiate mineralization.
Crystallites grows rapidly & rupture from vesicle
Fuses with adjacent clusters - form mineralized matrix
18. Fig: 1st:Matrix vesicle containing apatite crystals.
2nd:Crystals have ruptured from vesicles &
are joining with others to form mineralized
tissues.
18
19. 2.HETEROGENOUS
NUCLEATION19
Apatite crystals deposited in the surface,holes
& pores of collagen.
But collagen itself have no role in it’s initiation.
The non- collagenous protein fulfil this function
, although their role in mineralization process
is complex and not fully understood.
20. COLLAGEN
MINERALIZATION20
Collagen acts as a nucleating substance (which
has the effect of lowering the energy barrier)that
allows crystal formation to occur even in absence
of locally increase ionic concentration.
In the gap zones at the ends of collagen
molecules , the mineral first appears.
Initially, proteoglycans that bind with Ca are filled in
gap zones
PGs are now removed enzymatically by
proteoglycanase enzyme leaving behind the Ca
21. CONTD..
21
Phosphoprotein bind with the collagen
Immobilizes the phosphate and initiate 1st mineral
deposit
Alkaline phosphatase causes dephosphorylation of
phosphoproteins
Localized increase in Pi encourage the precipitation of
additional Ca phosphate complexes in the gap zones.
Rapidly convert into 1st hydroxy apatite crystal
22. CONTD..
22
Eventually hydroxyapatite crystals spread between
collagen fibrils to fully mineralize tissues.
Exception:
Neither of these mechanisms is involved in mineralisation of
enamel.
Since matrix vesicle and collagen is absent in enamel.
Initiation of enamel mineralisation is thought to be achieved
by crystal growth from the already mineralised dentin , by
matrix proteins secreted by the amelobasts .
Shape & size of crystals determined by enamel proteins of
matix
Mineral nucleation can also occur in relation to
noncollagenous matrix proteins
24. 1.CRYSTAL GROWTH
24
Initial mineralisation is rapid.
Later slower growth exceed their initial size by 10-
20 times.
Important factors influence crystal growth &
composition is it’s immediate environment of
growing crystal
Non- collagenous proteins bind selectively to
different surfaces of crystal ,preventing further
growth and thereby influence final size of crystal.
Pyrophosphate accumulation on crystal surface
also blocks further growth.
25. 25
NAME COMPOSITIO
N
LOCATION POSSIBLE
FUNCTION
NONCOLLAGENOUS PROTEIN
OSTEOPONTIN
OSTEONECTIN
PHOSPHOPHORY
N
BONE
SIALOPROTEIN
II
GLA PROTEIN
(OSTEOCALCIN)
PHOSPHOPROTEI
N
PHOSPHOPROTEI
N
PHOSPHOPROTEI
N
PHOSPHORYLAT
ED
GLYCOPROTEIN
PROTEIN & y-
BONE
,DENTIN
,CEMENTUM
DENTIN
EXCLUSIVE
DENTIN
BONE,DENTI
N
,CEMENTUM
BONE,DENTI
N, CELLULAR
CEMENTUM
Inhibit crystal growth.
Inhibit crystal growth.
Low concentration
induces hydroxyapatite
formation; high
concentration inhibit
crystal growth.
Nucleator for
mineralization.
Regulator for crystal
growth.
26. B
A
C
Fig.1
A
B
C
Fig.2
A
B
C
Fig.3
No inhibition
(block shaped
crystal)
Inhibition of the B
face alone (plate
shaped crystal)
Inhibition of growth of A and B faces(needle shaped crystal)
Eg: noncollagenous proteins are able to bind
selectively to various surfaces of crystal which
prevent further growth & thereby determining
shape of crystal
26
27. 2.SECONDARY NUCLEATION
27
Additional crystallites may form by secondary
nucleation from mineral-phase particles arising
from collision and fracture of crystals
previously form by heterogeneous nucleation.
28. TRANSPORT OF MINERAL IONS
TO MINERALIZATION FRONT28
1. Intercellular transport
Tissue fluid is supersaturated in these ions so
fluid simply needs to percolate between cells to
reach organic matrix
More likely to occur between osteoblasts and
odontoblasts
In case of enamel,secretory stage ameloblasts
restrict the passage of calcium, so majority of
calcium entry occur through transcellular route.
Sequestration of Ca to Golgi appratus,
Mitichondria &ER is a safety device to control
calcium concentration of cytosol
29. CONTD..
29
2. Transcellular transport:
Occurs only if cytosolic free Ca ion
concentration not exceed 10^(-6)M
2 mechanism :
i)Enters cell through specific Ca channels
& sequestered by Ca binding protein to the
site of release
ii) Continuous & constant flow of Ca ions
occurs across cell
30. LOCATION OF MINERAL
30
Minerals are not simply packed between the
collagen fibrils but also within it.
In bone: 70-80% of mineral is located within
the collagen fibril.
Location of such mineral is the result of
heterogeneous nucleation, followed by
secondary nucleation within the gaps of
collagen fibrils.
32. ALKALINE PHOSPHATASE
32
Key enzyme in the process of mineralization .
In hard connective tissue, found either associated with
matrix vesicles or occurring freely within matrix.
Capacity to cleave phosphate ions from organic
substrates at alkaline pH,increasing its conc. &
leading to deposition of apatite.
Ion handling when associated with cell membrane
Extracellular activity:
Helps in continuation of crystal growth by inhibiting
pyrophosphate.
Cleavs pyrophosphate to inorganic phosphate
No activity is observed in ameloblasts.
34. 1. Alkaline Phosphatase
Theory34
Alkaline phosphotase resides in matrix vesicle
It increases the conc. of ions to such a level
that leads to its precipitation.
Enzyme hydrolyses the organic phosphate
containing substrate and increases the local
inorganic phosphate conc.
Enzyme hydrolyses PPi (inhibitor of HA) &
provide Pi for the formation of HA crystals.
35. 2. Nucleating Theory
35
A nucleus formed in relation to collagen effective in
aggregating Ca & phosphate ions and grow to form
HA by addition of ions from supersaturated fluids
Possible seeding substances:
a. Ground substances : Glycosaminoglycans and
proteoglycans.
b. Collagen :
Initial mineral deposits at discrete sites in or on the
collagen fibrils
Allow ingress of ions, formation of ion cluster & its
aggregation to form nuclei for crystal growth
Phosphoproteins also indudce apatite formation.
36. 3. Matrix vesicle Theory
36
Matrix vesicle accumulte Ca ions & its
membrane furnish binding sites for nucleation of
HA crystals.
Vesicles formed:
1.Type 1:
Small membrane bound , budding off from cell
membrane as an independent unit within the 1st
formed organic matrix.
It helps in initiation of mineralization
2. Type 2: Cell degradation
3. Type 3: Extrusion of intracytoplasmic vesicles
37. ENAMEL MINERALIZATION
37
Cells secrete enamel proteins which immediately
participitate in mineralizing enamel(30%)
Bulk removal of enamel proteins and water makes
space for growth of crystal(95%)
No matrix vesicles are associated in
mineralization
No unmineralized matrix like that of predentin or
osteoid is seen
Therefore apatite crystals are not preformed when
they are released by the secretory granules.
Nucleation is initiated by apatite crystal of dentin
on which enamel is laid .
Enamel has no collagen involved in its makeup,its formation still follows many of the principles involved in the formation of hard c.t.
This complex are unique to mineralizing situation & when they are selectively removed, matrix vesicle can no longer initiate mineralization
Phospholipases trigger release of crystals leading to tisue calcification
Odontoblasts n osteoblasts hav no tight juctions
No activity observed in ameloblasts.
Alkaline phosphatase is the key enzyme in the process of mineralization . The enzyme liberates phosphate from substrates , so that ionic conc. of Calcium and Phosphate is increased to supersaturation level , leading to deposition of apatite
Annexins form a calcium channel thus incorporating ion within vesicles.