Biomedical Sciences and Oral Ecosystems I Biochemistry Lecture 8: Clinical Correlates

Flashcards covering key vocabulary from the lecture on Biomedical Sciences and Oral Ecosystems I Biochemistry, focusing on tooth structure, oral microbiota, dental diseases, collagen, mineralization, saliva, and dental treatments.

Pulp

The inner soft tissue of the tooth, vital for its health.

Dentin

The calcified tissue beneath the enamel, made by odontoblasts and calcified over type I collagen fibers. Supports and protects.

is 70% mineral and 30% protein

Enamel

The outermost, hardest calcified tissue of the tooth, made by ameloblasts, containing no collagen. It covers the tooth thus is in direct contact with oral cavity

97% by weight minreal and less than 1% by weight protein

Gingival sulcus

The shallow crevice or space between the tooth and the free gingiva.

Gingiva

The gums, forming part of the periodontium.

Periodontal membrane

A ligament that attaches the tooth to the alveolar bone; also called Periodontal ligament.

Alveolar bone

The bone that supports and surrounds the teeth.

Cementum

A calcified tissue covering the tooth root, made by cementoblasts and calcified over type I collagen fibers.

What are calcified over type 1 collagen fiber

Cementum and dentin

Osteoblasts

Cells that synthesize bone, transporting Ca2+ ions from blood into uncalcified matrix composed of type 1 collagen 

Ameloblasts

Cells responsible for making enamel, present only during tooth development.

Odontoblasts

Cells responsible for making dentin.

Cementoblasts

Cells responsible for making cementum.

Osteoclasts

Cells that resorb bone. (break down old bone)

Periodontium

Comprises the gingiva, cementum, periodontal ligament, and surrounding alveolar bone.

Fermentation

A metabolic process by which microbes obtain energy via glycolysis, producing lactate from monosaccharides in the oral cavity, often leading to dental caries.

Dental caries

Tooth decay resulting from microbial fermentations that produce lactate by glycolysis from monosaccharides.

Saccharolytic bacteria

Sugar metabolizing bacteria, predominantly found in the oral microbiota, whose major end product is lactic acid, contributing to dental caries. MOSTLY GRAM POSITIVE BATERIAL in saliva or oral mucosa

Asaccharolytic bacteria

Non-sugar metabolizing bacteria that hydrolyze proteins and utilize amino acids for energy, commonly found in the gingival sulcus. Causes more peridontal disease 

Gram + Bacteria

Thick cell wall, people that keep their teeth clean have more of this because thick walls are able to tolerate low pH caused by lactic production which then causes caries by dissolving tooth enamel and dentil

Gram - Bacteria

think cell wall and inner out membrane

Plaque (biofilms)

Teeth adherent bacterial biofilms responsible for common forms of periodontal disease and dental caries.

Mucins

Proteins found in our saliva, covered with numerous saccharide (glycan) residues.

Gingival crevicular fluid (GCF)

serum proteins from beneath a healthy gingival sulcus, providing an environment richer in proteins than saliva, suited for asaccharolytic microbiota.

How does ammonia affect pH orally

Metabolizes proteins → breaks down to AA→AA breaks down to ammonia →pH raises →no caries →perio disease

ammonion accumulates enough to make the environemt alkaline which prevents caries from developing beneath the gingival suculs

Dental calculus

Precipitated calcium and phosphate ions from GCF in an alkaline environment, which forms more calculus and tartar

H2S (Hydrogen sulfide) and oral malodor

When sulfur-containing amino acids (cysteine and methionine) are metabolized, they release H₂S along with ammonia

H₂S is a major contributor of oral malodor that often accompanies moderate to severe periodontal disease

Collagen Synthesis importance

colleagen synthesis and degradation are central to the well being of teeth and periodontium. Only enamel is the only calcified tissue that does not contain collagen

Fibrilla collagen is synthesizes by 5
Fibroblasts (ECM)
chondroblast (cartialge)
osteoblasts(bone)
odontoblast( dentin)

cemntoblasts(cementum

What amino acid is collagen mostly made up of

Glycine and Proline, a little hydroxyproline and hydroxylysine

Collagen Synthesis

1. Nucleus 

2. Translated then  enters RER (select Proline and Lysine residues are hydroxylated the glycoylstte with glucose/ galatacose

3. Procollagen is formed where a triple helix is formed then enters Golgi to be secreted

4. Secreted into the ECM 

5. Tropocollagen formation when terminals of N and C terminales petipids are cleaved by Peptiases

6. Multiple  tropocollagen formed into collagen wihen cross linking occurs

Oral disorders related to collagen

• Mutations of glycine residues → inhibits adequate triple  helix formation 

• Results in Fragile bones (oseteogenis imperfecta) 

Dentinogenesis imperfecta: 

opalescent(blue/grey, yellow brown) or completely missing  teeth 

Ascorbate

antioxidant (reducing agent) important for making collagen and protects marcromolules from oxidative damange by ROS

essential for proline and Lysine hydroxylate functioning in vertebrates

L-gulonolactone oxidase

an enzyme human lacks that makes ascrobate which is why we need to take vitamin C

Why is Ascrobate needed INTRACELLULAR

Cells possess large amounts of catalase, peroxidase and SOD enzymes that rapidly neutralize ROS within the cytosol

Why is Ascrobate needed EXTRACELLULAR

antioxidant properies neutrizlies ROS extracelluar from leukocytes during inflammation

Early symptoms of ascrobate defiency

loss of gingival and periondontal memrbane fivers with loosening of teeth. Can’t keep up with turnover rates due to our 24 hr teeth movement and renewal

Scruvy

developes in absense of asrobates preventing collagen resynthesis in respsone to stress in tusses such as gingiva blood vessels and bone. Fibers are removed but not replaced

Keratin

found in hair wool skin horsn and finger nails composed of a-helical polypeptides

Keratin in the teeth

The cells of the outer surface of the hard palate and gingival mucosa are said to be parakeratinized (not fully keratinized) like the skin

The nonkeratinized regions of the oral mucosa (cheeks, lips, ventral surface of tongue, soft palate) are permeable to fluids and small molecules

Does Pulp exhibit mineralization?

No only enamel and dentin do and hardness is related to ability to form calcium salts

What is the primary crystalline mineral that makes up the calcified tissues of teeth and bone?

Hydroxyapatite, a form of calcium phosphate.

Unit cell of hydroxyapatite

Ca10 (PO4)6 OH2)

How is enamel formed?

Formed by organzing proteins enamelin and amelogenins which are secreted by ameoloblasts and mineralize to form enamel.

What happens when hydroxyapatite OHs are replaced by fouride

Flouroapatite Ca10 (PO4)6 F2 

It becomes more solid (resistant to low pH) and more insoluble

Scaffolding Proteins

When the conditions of high concenrate of ions are met for mineralization with proteins

ex. collogen (odontoblasts) or Amelogenins (Ameoblast)

Nucleation

when we seed the environemt with the right factors and add ions we will get mineral

How is dentin and enamel mineralizes

Enamel is mineralized towards the crown and dentin is mineralized towards pulp

How is enamel changed after tooth eruption

Saliva bathes the teeth which is filled with calcium and phosphate ions and bufffers around pH 7

Dentinal Fluid

exuded by odontoblasts which line the pulp cavity purges the enamel of bacterial waste

Bacteria Waste Products

Aerobic: H20 and CO2

anaerobic: latic acid

The deeper the plaque the more anaerobic and the more acid and lower the pH

At which pH does demineralization occur

at pH 5.5

How do we combat demineralization

Crystallites are stablized from acidic proline which would bind to calcium 
Staterine is aprotein that maintains high calcium level in saliva 

Factors that lead to resistant to dental caries

Minimize sugar intake, brush and floss, stimulate salivary flow by drink lots of water.

Flouride will inhibit enolase in bacteria from making pyruvate to lactate 

What is the optimal amount of Flouride

1 ppm of flouride in water 

<= 1 ppm flouride in drink water = index of flurosis essentially zero
8-10 ppm flouride leads to severe of flurosis

>1 which leads to mottled enamel 

50-100 ppm Flouride leads to what?

It inhibits gluconeogenis by binding Mg 2+ ions that activate fructose biphosphate phosphatase and protein synthesis initation. We dont get furctose 6- phosphate for energy

It also inhibits ROS elimination by binding iron, selenium, and molybedium ions at catalyic centers of catalase, peroxidase, and superoxide dismutase

Bone remodeling

bone is broken down by osteoclast and remineralized by osteoblast
This is caused by stress induced bony microcracks that attract ciruclate WBCs  which has demineralizing compartments that breaks down microcracks and osteoclast dissppeas and osteoblast lay down new bones

only Cementium and dentin can be remoled

Most abundant mineral

Calcium is and intracelluarly they are retainined in the ER or sarcoplasmic rectiuclum (muscles)

The major mineral material used in mineralization of bones

Major Saliva glands

Parotid, submanidbular, and sublingual

What are submandibular and sublingar glands composed of

Clusters of epithelial like cells called acinar cells which secrete a serous (watery fluid) and tubular cells secreting a muscous (viscous) fluid

What are Parotid composed of

Only ACINAR cells

Components of Saliva 

Water, sodium chloride (electrolye), sodium bicarbonate (stablilze tooth surfcae), Mucin proteins, a-amylase (digestive starch), Proline Rich protein

ammonioa, calcium , phosphate

When is salivary secretion stiumulated

by the odor or taste of food that provides a neuro stimulus

Xerostomia

Dry mouth when major salivary glands is lost from trauma or diseaes and oral cavity becomes dry

Periodontitis

diseaes describes a mixture of diseases in which the periodonal attachehment is destroyed resulting in loose teeth

Chronic periodontitis first appears at the gingival suclus 

How can mouthwashes treat periodntitis

they have antisepectic properties that control successor microbiotor, but a need for 15-20%(21.6%) alcohol to maintain “essential oil” solubility has been linked to an increased risk of oral cnacer in longtime daily human users (inconclusive)

alcohol free mouthwashes

Contains antisepctic [chlorheixdine[peridex]] which can interfere with taste and probiosis (commensalism microbioat) without the risks of alcohol

Inflammation Periodontal Repair

Prostaglandinds and thrombonanes are proinflammatory molecules that can control chronic periodontitis

Relationship between Sugar and dental caries

Rise of caries is coincided with increase sucrose consumption

How does Teeth Whitening Work

Bleaching chemicals can pentrate the tooth enamal and cause a oxidation reaction that breaks apart staining compound. When oxygen reacts with stain particles it breaks the stain particle producing small ighter in color particles

Chemical Agents of Tooth Whitening

carbamide Perioxide (has urea) + hydrogen perioxide

carbamide breaks down into hydrogen peroxide and urea with hydrogen peroxide being the acive whitening ingredient 

Side Effects of Tooth Whitening

Can cause tooth sensitivy to tempaure and possible pulp reponse to H2O2 that penatreates. It can also oxidize the peripheral keratin layers of the gingiva which leads to a dead white color

Hemostatis

Blood clotting

Two Routes to blood clot formation

Intrinsic and extrinsic

Intrinsic Pathway

When blood comes into a physical contact with abnormal vessel wall

Initial Pathway of Instrinsic Pathway

Damaged surface → kiniogen Kallilkrein that actives protein 12 A

Extrinsic Pathway

initated by factors released from injured tissues (rputure blood vessels)

Initital Pathway of Extrinisic Pathway

Truama leads to F7 being activated then once activated it attaches with tissue factors. (This happens beyond the blood vessel no Endo)

Final Common Pathway of Coagulation

Prothorombin (II) actives Thrombin (IIa) then leads to Fibrinogene (I)getting activated to Fibin (Ia) then the final action is Cross-linked fibrin 

Hemophillia

mutations of coagulation protein which leads to life long excessive bleeding (ultimately leading to large amounts of bleeding from a tooth extraction)

Factors that can affect blooding clotting

diseases, drugs, hemophilia, chronic inflammation. 

Consequences of Bleeding and blood clotthing

Heart attack stroke, pulmonary obstruction, or peripheral necrosis.

Conditions are higher in older adults because of blood vessel degernation or decreased blood flow and it can also lead to clots that obstruct circulation and can cause an embolism elsewhere in the body 

Durgs that reduce Clot formation

Heparin Coumadin Warfarin Aspin Ibprofen


HCWAI

Durgs that promote clotting

Episolon-aminocaprioc acid and tranexamic acid

Astrigents

subtantts that tend to shirnk or constrict body tisses to stop hemorrage from inflamed pulp and gingiva

zinc, iron, and aluminum salts are the best astrigents used in dentistry

Aluminum Chloride

used in gigival retraction because it causes contraction and shrink of tissues which can preipcpate proteinm constrict blood vessels, and extract fluid from tissues

Ferric Subsulfate Solution

More Potent astringent on an open wound results in agglutination of surface protein leading to quick and efficent hemostatis