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"
Cementum also commonly known as root cementum , is a highly mineralized tissue covering the entire root surface.
Cementum is also often referred to as a bone-like tissue. Cementum contains two types of fibers, mainly extrinsic (Sharpey's) fibers and intrinsic fibers. Fibroblasts and cementoblasts are the fiber secreting cells.
Cementum forms a functional unit which is designed to maintain tooth support, integrity, and protection.
Minor, non-pathological resorption defects on the root surface are generally reversible and heal by reparative cementum formation.
Irreversible damage may occur when the cementum is exposed to the environment of a pocket or oral cavity.
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"
Cementum also commonly known as root cementum , is a highly mineralized tissue covering the entire root surface.
Cementum is also often referred to as a bone-like tissue. Cementum contains two types of fibers, mainly extrinsic (Sharpey's) fibers and intrinsic fibers. Fibroblasts and cementoblasts are the fiber secreting cells.
Cementum forms a functional unit which is designed to maintain tooth support, integrity, and protection.
Minor, non-pathological resorption defects on the root surface are generally reversible and heal by reparative cementum formation.
Irreversible damage may occur when the cementum is exposed to the environment of a pocket or oral cavity.
Cementum is the calcified, avascular mesenchymal tissue that forms the outer covering of the anatomic root.
it describes the development of cementum and its various types.
this ppt includes information regarding a dental tissue know as the cementum.
It is a hard tissue covering the roots of the teeth.
this ppt includes, the composition, formation, types, cells and functions the cementum plays in maintaining the integrity of the tooth .
cementum is avascular connective tissue
it attaches tooth to alveolar bone via pdl in this seminar i explained about charecterestics of cementum &anamolies and some pathological conditions associated with it
Cementum /certified fixed orthodontic courses by Indian dental academy Indian dental academy
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Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
3. Cementum is a calcified , avascular mesenchymal
tissue forming the outer covering of the anatomic
root.
Begins at the cervical portion of the tooth at CEJ and
continues to the apex
Avascular and non- innervated.
Furnishes a medium for attachment of that help to
bind the root to surrounding alveolar bone.
4. COLOUR: Yellow,lighter than dentin but darker than
enamel (darker hue and lacks lustre)
HARDNESS: Lesser than dentin, more resilent,
PERMEABILITY: Permeable to inorganic ions,bacteria;
which diminishes with age ;cellular cementum is more
permeable than compared to acellular cementum
THICKNESS:
-Coronal half of root-16-60microns
- apical third & furcation areas-150-200microns
-An average thickness of 95microns (20yrs) and
215microns (65 yrs)
5. Organic components
Calcium and phosphorus in
the form of hydroxyapatite
crystals.
Fluoride ( highest
concentration)
Trace metals-Mg,Zn
Inorganic components
Type I collagen in addition
to types III,V,VI,XII
Protein polysaccharides-
proteoglycans
Non-collagenous protein
BSP,CAP,osteopontin
,Chondroitin
sulfate,heparin sulfate,etc
6. Formation of cementoblasts-differentiation occurs when
cells of dental follicle comes in contact with newly formed
dentin
Organic matrix-collagen and protein polysaccharides-the
collagen fibrils (cementoblasts) forms a fibrous fringe
perpendicular to periodontal space,incremental lines of Salter.
Mineralization –cementoid ( uncalcified matrix),Ca and P ions
are deposited as units of hydroxyapatite
-Gla protein –osteocalcin ,osteonectin-nucleators
-BSP,alkaline phosphatase-promotes mineralization
-Osteopontin,lumican,fibromodulin,insulin like growth
factor- -regulates growth of crystals
Cementoid –Sharpey’s fibers
8. Schroeder’s classification
Acellular afibrillar cementum- contains neither cells
nor extrinsic (sharpey’s) or intrinsic collagen
,product of cementoblasts,found as coronal
cementum -1 to 15microns
Acellular extrinsic fiber cementum-densely packed
bundles of sharpey’s fibers,lacks cells,product of
cementoblasts & fibroblasts,found in cervical third
of roots-30-230microns
12. Structureless-apical 2/3rd of roots of roots of molars and
premolars –hyaline layer
Represent areas where cells of HERS become trapped in
rapidly forming dentin or cementum matrix
Dentinal origin-contain wide spaces –enlarged terminals
of dentinal tubules
Amorphous layer of non collagenous material devoid of
odontoblasts and cementoblasts
First described by Bodecker(1878)-interzonal layer
Hopewell –Smith (1920),homogenous layer between
Tomes granular layer and cementum
14. Three types of relationships between cementum and
enamel is seen broadly-
1. Cementum overlapping enamel-60-65%
2. Edge to edge ,butt joints-30%
3. Cementum fails to meet enamel-5-10%
Recent observations by optical microscopy showed presence of a
fourth type of junction –enamel overlapping the cementum
16. Though different functions are attributed to the different
types of cementum it functions as a single unit
1. Anchorage-furnishes a medium for attachment of
collagen fibers to bind roots to alveolar bone
2. Adaptation-deposition of cementum in apical region
can compensate for loss of tooth substance dueto
occlusal wear ( attrition)
3. Repair – damages to root (fractures resorptions )can be
repaired by deposition of new cementum
17. The terminal apical area of the cementum where it joins
the internal root canal dentin- dentinal surface upon
which cementum is deposited
CDJ - relatively smooth in permanent teeth
-scalloped in deciduous teeth
Wide zone containing large quantities of collagen
associated with glycosaminoglycans like chondroitin
sulfate and dermatin sulfate .
Cemental fibers intermingle with the dentinal fibers more
in case of cellular cementum than in acellular cementum
at CDJ- attachment
19. Abnormal thickening of cementum-diffuse or circumscribed : age
related phenomenon- 200-215 microns with progressing age.
Generalized thickening-nodular enlargement of apical third of the
root.-Paget’s disease,rheumatic fever.
Localized hypercementosis-formation of spur/pong like
extensions,around enamel drops-benign cementoblastoma, florid
cemento-osseous dysplasia,acromegaly,calcinosis,arthritis.
Cemental spikes created either by coalescence of cementacles that
adhere to the root or the calcification of PDL at sites of insertion.
Radiographically –radiolucent PDL space and radiopaque lamina
dura seen as outer border of hypercementosis.
Doesn’t require treatment but poses problems during extraction.
Hypoplasia /aplasia of cementum is rare-hypophosphatasia.
21. Cementacles- Calcified oval or round nodules found in the PDL,
single or in groups.
The origin may be calcified epithelial Cells (Rests of Malassez)
They may be free or attached or embedded in cementum.
They act as nidus favoring the deposition of concentric layers
of calcosherites around the degenerated or hemorrhagetic
areas .
Cementicles may be:
1. Free in the periodontal ligament.
2. Attached to the cementum and form excementosis.
3. Embedded in the cementum during its growth by age.
23. Fusion of cementum with alveolar bone with obliteration of
the PDL
Represent abnormal repairs, develops after chronic periapical
inflammation ,occlusal trauma ,implants etc
Radiographically –resorption lacunae are filled with bone and
periodontal space is absent
Clinically-absence of physiological mobility of normal tooth,
exhibits metallic percussion, infraocclusion (process
continues)
Formation of true periodontal pocket due to lack of apical
proliferation of epithelium around root.
Titanium implants-direct bone apposition without intervening
connective tissue
25. Orthodontic treatment- cementum is more resistant to resorption
than bone –migration of tooth occurs
Cementum resorption occurs in case of extensive occlusal forces
/trauma- leads to functional /anatomical repairs
Transverse fractures of root are healed following trauma.
Small fragments of roots left in sockets following extractions are
surrounded by cementum –causing no trouble
Cementum becomes exposed to oral environment ( gingival
recession & pocket formation)
Bacterial invasion results-formation of hyper mineralized (
Ca,F,P),decrease in cross striations of collagen: lipopolysaccharides
confined to surface
Cemental caries can be seen on exposed surfaces of cementum with
gingival recession in older individuals
27. Cementum is an avascular mineralized tissue covering the entire
root surface. Due to its intermediary position, forming the
interface between root dentin and periodontal ligament,
cementum is a component of the tooth itself, but belongs
functionally to the dental attachment apparatus, that is, the
periodontium.
One of the main functions of cementum is to anchor the principal
collagen fibers of the periodontal ligament to the root surface, but
it also has important adaptative and reparative functions, playing a
crucial role to maintain occlusal relationship and to protect the
integrity of the root surface.
Dental cementum is unique in various aspects: it is avascular and
not innervated, does not undergo continuous remodelling like
bone, but continues to grow in thickness throughout life.
28. In contrast with these specific histological characteristics, it
appears not to be specific at the cellular and molecular level.
Unlike dentine and enamel, where there are clear differences in
the proteins present in these tissues and the factors regulating
their functions when compared with bone, cementum has not
demonstrated to express specific proteins, appearing to contain
factors in common with bone and to be developmentally
controlled by similar factors
RESEARCH AND DEVELOPMENTS: The relationship between
osteoblasts and cementoblasts, provides more information
regarding the specific mechanisms involved in maintenance of
cementum structure and function in humans on the cellular and
molecular level. Similarly, the in vitro/in vivo system can also be
used for further elucidation of the modes of action of current
available regenerative products, such as Emdogain, with apparent
cementum-growth-promoting activities.