DH1 Exam 3 Review

What are the clinical features of a yellow stain?

Dull, yellow; <30% localized or >30% generalized

At what age can yellow stains occur?

Any age

In what conditions are yellow stains commonly found?

Unhealthy oral routine

What is a common etiology for yellow stains?

Dietary problems

What are the clinical features of green stain?

Yellowish, dark green

Where is green stain typically distributed on the tooth surface?

Facial 1/3rd of maxillary anterior teeth

At what age is green stain most commonly found?

Most commonly found in children or babies

What condition is associated with the occurrence of green stain?

poor oral hygiene, chromagenic bacteria

What can cause green stain?

Poor oral hygiene and chromogenic bacteria

What are other causes of green stain?

Metallic dust, factory workers, or marijuana use

What is another name for black-line stain?

Brown stain

Where does black-line stain typically occur in relation to the gingiva?

About 1mm above the marginal gingiva

In which areas of the teeth can black-line stain be found?

In pits and fissures

What is a primary cause of black-line stain?

Too much iron in water

What type of bacteria is associated with the formation of black-line stain?

Chromogenic bacteria in saliva

At what age is black-line stain most commonly found?

In children with clean mouths

What is a common characteristic of individuals who have black-line stain?

They often have clean mouths

What color can a tobacco stain be?

Light brown to leathery brown-black

What part of the tooth does a tobacco stain typically cover?

Cervical 1/3rd of the crown

Can a tobacco stain penetrate the surface of the tooth?

Yes, it can penetrate and become intrinsic, but it is still exogenous.

What are common sources of tobacco stains?

Chewing tobacco, smoking, or hookah

What is a brown pellicle?

A thin film that forms on teeth, contributing to brown stains.

What color can stannous fluoride stains be?

Light brown or yellowish, especially with continuous use.

What types of food can cause brown stains on teeth?

Pigmented food.

What is an antibiofilm agent that can cause brown stains?

Chlorhexidine.

What is a cultural practice that can lead to brown stains on teeth?

Betel leaf chewing.

What is swimmers stain?

A brown stain that occurs frequently on incisors due to exposure to hot tubs or pools.

orange stains

-on cervical 1/3rd of anterior teeth, caused by chromogenic bacteria or poor oral hygiene.

What causes metallic stains in industrial workers?

Metals or metallic salts from metal containing dust inhaled by industrial workers not wearing a mask.

What types of substances can contain metallic stains?

Metallic substances contained in drugs.

What color does copper or brass stain?

Green or bluish green.

What color does iron stain?

Brown or greenish brown.

What color does nickel stain?

Green.

What color does cadmium stain?

Yellow to golden yellow.

What is dental fluorosis?

A condition characterized by mottled enamel, previously known as brown stain.

What causes enamel hypomineralization in dental fluorosis?

Ingestion of excessive fluoride ions during enamel formation.

What type of cells are damaged in dental fluorosis?

Ameloblasts.

What discoloration may occur due to dental fluorosis?

White or brown discoloration or spots on enamel.

Is dental fluorosis a cosmetic issue?

Yes, it is purely cosmetic.

What is a potential effect of tetracycline on bones and teeth?

Tetracycline can be absorbed by the bones and teeth.

Can tetracycline be transferred to a fetus?

Yes, tetracycline can be transferred through the placenta and enter fetal circulation during the 3rd trimester.

What type of discoloration can tetracycline cause in primary teeth?

Tetracycline can cause discoloration of primary teeth.

How can the discoloration from tetracycline vary?

Discoloration may be localized or generalized, depending on the duration and amount taken.

What colors can tetracycline-induced discoloration appear as?

Discoloration may appear light green, dark yellow, or gray-brown.

What are extrinsic stains?

Stains that occur on the external surfaces of the teeth.

How can extrinsic stains be removed?

By polishing, scaling, and brushing.

What are examples of extrinsic stains?

Yellow stain, green stain, black-line stain, tobacco stain, brown stain, orange and red stain, metallic stain.

What is an intrinsic stain?

A stain that cannot be removed by polishing, scaling, or brushing.

What are some causes of intrinsic stains?

High fevers, tetracycline, trauma, and too much fluoride.

Can intrinsic stains be removed?

No, once intrinsic, always intrinsic.

Exogenous

-may be extrinsic or become intrinsic

-due to outside forces, wine, coffee

endogenous

-always intrinsic

-originate inside the tooth, discoloration of dentin.

What are the inorganic contents of calculus?

Ca, P, CO3, Na, Mg, and K

What are the organic contents of calculus?

Desquamated epithelial cells, WBC, Mucin from saliva - mucus

What factors affect calculus formation?

Salivary flow, salivary supersaturation with calcium phosphate salts, and inhibitors and promoters of calculus formation.

What are the driving forces for mineralization in calculus formation?

Supersaturation of saliva and plaque biofilm.

What are calculus inhibitors for supra gingival calculus?

Pyrophosphate and zinc salts.

What do heavy calculus formers have in their saliva?

High salivary levels of calcium and phosphorus.

How soon can mineralization begin with poor oral hygiene?

Mineralization can begin as early as 24 to 48 hours.

What is the average time for soft deposit to change to mature mineralized stage?

The average time is 12 days.

What factors influence the formation time of calculus?

Formation time depends on genetics, diet, and amount of bacteria present.

How does calculus form on tooth surfaces?

Calculus forms in layers parallel with the tooth surface.

What separates the layers of calculus?

The layers are separated by lines that appear to be pellicle.

What happens to the pellicle as mineralization progresses?

The pellicle becomes imbedded.

What are the lines between the layers of calculus called?

Incremental lines.

What is the nature of the Acquired Pellicle?

Acellular

Is the Acquired Pellicle mineralized?

Nonmineralized

What is the physical form of the Acquired Pellicle?

Amorphous (no shape)

What type of material is the Acquired Pellicle primarily composed of?

Organic

What barrier does the Acquired Pellicle provide?

Barrier against acids (may aid in reducing dental caries attack)

What is the thickness range of the Acquired Pellicle?

0.1-1 micron (greatest near gingival margin)

Where does the Acquired Pellicle form?

Over exposed tooth surfaces (restorations and calculus)

How quickly does the Acquired Pellicle form after clearing teeth?

Within minutes

What is the main source of glycoproteins in the Acquired Pellicle?

Saliva

How does the Acquired Pellicle interact with tooth surfaces?

Absorbed by the hydroxyapatite of tooth surface (becomes a highly insoluble coating)

What surfaces does the Acquired Pellicle coat?

Teeth, calculus deposits, restorations, and complete and partial dentures

What is the appearance of supragingival pellicle?

Unstained, clear or translucent

Is supragingival pellicle readily visible?

No, it is not readily visible

What can stain supragingival pellicle?

Disclosing agent

What types of extrinsic stains can supragingival pellicle take on?

Brown, grayish, and other colors

Subgingival pellicle

-continuous with supragingival pellicle and becomes embedded in tooth.

-especially demineralized areas (soft enamel) ideally.

Oral biofilm

a complex, highly organized, 3D communal arrangement of microorganisms adhering to a surface where moisture and nutrients are available.

What are the functions of bacteria in a dental biofilm community?

Bacteria in dental biofilm can maximize nutrient transport, keep the community clean of waste, communicate when threatened, protect the community under attack, and relocate to start new biofilm communities.

Where do biofilm colonies attach?

Biofilm colonies attach to a moist environmental surface.

What does biofilm protect associated bacteria from?

Biofilm protects associated bacteria by resisting antibacterial agents and host defense mechanisms.

What is the composition of the network that protects biofilm bacteria?

The network consists of slime layers of polysaccharides.

Which immune cells are resisted by biofilm?

Biofilm resists neutrophils, leukocytes, macrophages, and lymphocytes.

How do biofilms create a source for long-term survival?

They create their own renewing source of lipopolysaccharide.

What do bacteria within a biofilm store to extend lactic acid production?

They store sugars.

What is a consequence of lactic acid production by bacteria in biofilms?

Decalcification and dental caries.

How does the presence of biofilms affect bacterial survival in the mouth?

Bacteria become more likely to survive within the mouth.

What effect does biofilm survival have on oral disease?

Oral disease becomes more chronic.

Why is periodontal disease difficult to control?

The self-sustaining nature of biofilms helps explain this difficulty.

What is the first stage of biofilm formation?

Pellicle formation

What occurs during the initial attachment of planktonic bacteria?

Planktonic bacteria attach to the pellicle.

What promotes bacterial adhesion to the pellicle?

Salivary proteins and peptides.

When does bacterial colonization of the pellicle begin after cleaning tooth surfaces?

Within 1 hour.

What can happen to cells if they are distributed during biofilm formation?

They can dislodge and either be eliminated or begin formation elsewhere in the oral cavity.

What occurs during the colonization stage of biofilm formation?

Micro colonies form in layers, growing upward and outwards to create a 3D structure.

What do bacteria secrete to help biofilm stay attached?

Bacteria secrete extracellular polysaccharides.