Dental hygiene Flashcards
Dentitions of teeth
Primary dentition
Mixed dentition
Permanent dentition
primary dentition
formation begins in utero
mixed dentition
when primary teeth are being exfoliated and permanent teeth are moving in to take their place
mixed dentition occurs
between ages 6 and 12
permanent dentition mineralization
starts at birth and continues or until adolescence.
Roots have normally completed growth
by 3 years after eruption
the WHO
world health organization
the WHO defines caries as
a localized post-eruptive, pathologic process of external origin involving softening of the hard tooth tissue and proceeding to the formation of a cavity
true or false: Dental caries is a preventable disease
True
Dental caries are communicable and its a hygienists job to
educate patients to prevent the spread of dental caries.
development of dental caries requires
microorganisms, carbohydrates and susceptible tooth surface.
Dental biofilm may contain numerous types of acid-forming bacteria specifically:
Mutans Streptococci and Lactobacilli
who developed the standard method of classifying caries.
G.V Black
the categories of G.V Blacks classifcations of cavities are used for
Caries, preps and finished restorations
Nomenclature by surface
Simple cavity, compound cavity and complex cavity.
Simple cavity
involves one surface
Compound cavity
involves two tooth surfaces.
Complex cavity
involves two or more tooth surfaces.
Phase I in formation of a cavity
incipient lesion
Phase II of formation of cavity
Untreated incipient lesions
During Phase I of formation of a cavity
subsurface demineralization happens
Subsurface demineralization
acid passes through from surface enamel to subsurface area in the dentin
Visualization during Phase I of formation of a cavity
area of demineralization not visible by clinical observation
First clinical evidence of cavity formation
white area appears with no breakthrough to enamel.
During Phase I of cavity formation you can try to reverse cavity by
remineralization.
Remineralization
low concentrations of fluoride applied frequently during early phase can provide sources for uptake by demineralized area.
Sources of fluoride can be:
dentifrices, mouth rinse, fluoridated water and all possible sources.
Untreated incipient lesion
Breakdown of enamel over the demineralized area.
Vision during Phase II of cavity formation
Visible to observation and irregular to touch with explorer.
Formation of cavity steps.
Sugar source ( any carbohydrate) + bacteria (Plaque) --> formation of acid = cavity. Bacteria eats sugar source and creates bi product which is acid and acid lying on teeth will cause a cavity.
Progression of carious lesion
follows general direction of enamel rods
spread of carious lesion
spreads at dentinoenamel junction; continues along dentinal tubules.
Types of dental caries (by location)
Pit and fissure.
Smooth surface.
Pit and fissure caries
caries can begin in a minute fault in enamel.
Pit and fissure irregularity occurs where 3 or more lobes of developing tooth join.
occurs at endings of grooves of teeth (buccal groove.)
smooth surface caries.
caries can begin on smooth surfaces where the are no faults.
It can occur in hard to clean areas. (Proximal surfaces.)
ECC
Early childhood caries
Early childhood caries classified as
1 cavity before the age of 5 years old.
other names for ECC
nursing bottle mouth, baby bottle syndrome, baby bottle caries and prolonged nursing habit.
Early childhood caries are a
form of caries found in young children.
Common cause of ECC are
use of nursing bottle (with milk or sweetened beverage) when going to sleep
Predisposing factors of ECC
bottle that contains sweetened ilk or other sweetened liquid.
Pacifier dipped or filled w/ sweet agent (honey.)
Prolonged breast feeding
Hygienist must
educate parents about cause and effects of early childhood caries
Microbiology of ECC
high levels of Mutans streptococci and Lactobcailli
Teeth first effected by ECC
Maxillary anterior teeth and primary molars.
w/ ECC while baby sleeps
sweet liquid pools around the teeth, the nipple covers the mandibular anterior teeth so they are rarely affected
Children need to be seen for exam no longer than
6 months after eruption of first tooth
If there is a problem with a childs teeth
it can be detected early and preventative procedures can be taught to the parent.
At later stages dark brown lesions could occur and crowns of teeth could be destroyed, and child could even develop an abscess.
Root caries
a soft progressive lesion of cementum and dentin
Other names for root caries
cemental caries, cervical caries and radicular lines
root caries are common in
older population
Steps in formation of root decay
- Gingival recession exposes the cementum
- Caries start near the CEJ. Cementum is thin and soon destroyed; dentin is invaded.
- enamel not involded unless by extension. Root caries occur in a mildly acidic environment.
- Mutans streptococci and lactobacilli are primary organisms involved.
Root caries has been shown to be directly related to
Fluoride concentration in drinking water
Clinical recognition of root caries
soft, shallow ill-defined lesion.
Increases laterally to coalesce with other small lesions and eventually extend around the tooth.
Color of root caries
yellowish, light brown, dark brown to black
texture of root caries
leathery in texture when explored
Arrested root caries
appear dark but are hard to touch with explorer
Noncarious dental lesions
Enamel hypoplasia. Attrition. Erosion. Abrasion. Fractures of teeth
Enamel hypoplasia
defect that occurs as result of a disturbance in the formation of the organic enamel matrix
Hereditary enamel hypoplasia
Ameliogenesis imperfecta. -Enamel is partially or wholly missing.
Enamel hypoplasia can be
hereditary or systemic
Systemic enamel hypoplasia
Environmental
Factors that may contribute to enamel hypoplasia during tooth development include
Severe nutritional deficiency. Fever producing diseases (measles, chickenpox, and scarlet fever.) Congenital syphilis. Hypoparathyroidism. Birth injury. Prematurity Rh hemolytic disease Fluorosis.
enamel hypoplasia can affect
single tooth or multiple teeth.
Trauma or periapical inflammation of primary tooth can cause
injury to the developing permanent tooth.
hereditary enamel hypoplasia may appear
brown in color
Systemic hypoplasia
Single narrow zone (smooth and pitted)
Multiple- occurred over a period of time
Local enamel hypoplasia
single tooth with a yellow or brown intrinsic stain
Attrition
wearing away of a tooth as a result of tooth to tooth contact
attrition may be found
on occlusal, incisal and proximal surfaces.
Attrition increases
with age (but not because of age) as bruxism continues over time.
More attrition occurs in
Men than women
Bruxism
Predisposing factors may be psychological, tension, or occlusal interferences.
Predisposing factors for attrition may be
coarse foods, chewing tobacco, or abrasive dusts associated with certain occupations.
Initial lesion of attrition
small polished facet on cusp tip or ridge, or slightly flattened incisal edge.
Advanced attrition
Gradual reduction in cusp height; flattening of occlusal plane
Staining of exposed dentin (attrition)
Discoloration may occur; stains are usually brown.
attrition on radiograph
pulp chamber and canals may be narrowed and st obliterated
Erosion
Loss of tooth substance by a chemical process that does not involve bacterial action
Location of erosion
Facial or lingual surfaces depending on cause.
Etiology
Lesion is caused by some form of chemical dissolution
Erosion causes
May be idiopathic. Chronic vomiting- Acid of chronic vomiting affects lingual surfaces particularly anterior teeth. Pregnancy. Eating disorders. Chemo therapy.
Extrinsic factors of erosion
Industrial- workers teeth exposed to atmospheric acids.
Dietary- facial surfaces mostly affected.
Carbonated beverages.
Lemons or other citrus fruit.
Appearance of erosion
Smooth, shallow, hard and shiny.
Shape varies from shallow saucer-like depressions to deep wedge-shaped grooves.
Erosion may progress to involve
Dentin
erosion may occur in combination with
calculus, caries or restorations.
Abrasion
Mechanical wearing away of tooth substance by forces other than mastication
Abrasion occurs at
Exposed root surfaces.
incisal edge.
Etiology of abrasion
originates from mechanical abrasive activity.
common cause is abrasive dentifrice applied w/ horizontal toothbrushing.
Appearance of abrasion
V or wedge shaped with hard smooth, shiny surfaces.
Fractures of teeth
Abfractures.
Causes of tooth fractures
Automobile, bicycle and driving accidents.
Contact sports when mouth guards are not worn.
Blows incurred while fighting.
Falls.
Line of tooth fracture
Horizontal
Diagonal
Vertical
Tooth fractures on radiographs
Widened perio ligament space.
Radiolucent fracture line.
Radiopaque area where fracture overlaps.
Tooth displacement
Preparation to recognize various lesions
Dry each tooth with air.
Carefully inspect each surface, both visually and gently with explorer
Visual examination of enamel caries
Changes in color and translucency of tooth surface.
Changes are either definite signs of decay or may lead to suspicious caries.
Variations in color and translucency of enamel caries
- Chalky white areas of demineralization.
- grayish white discoloration or marginal ridges.
- grayish white spreading from margins of restorations.
- open lesions may vary from yellowish brown to dark brown.
- dull, flat opaque areas under direct light show loss of translucency.
- dark shadow on a proximal surface may be shown by transillumination.
Around amalgam restorations enamel caries may appear
Translucent in outer portions and white or opaque adjacent to the amalgam.
With enamel caries discoloration is generally less severe when
Dental caries progress rapidly
Technique for exploring smooth surfaces during exploratory exam
Adapt side of explorer closely to the tooth surface. Examine for roughness Vs. smoothness and continuity of tooth surface Vs. breaks in continuity
Exploring restorations surging exploratory exam.
Follow margins of all restorations around with explorer. Overhangs may or may not show on radiographs. Chart all irregularities of existing restorations.
Radiographs used for
Supplemental confirmation
Clinical and radio graphic exam must be
Completely together. Neither is complete without the other.
For coronal caries during radiographic exam
Use horizontal BW’s
For root caries during radiographic exam
Use vertical BW’s.
Vertical BW radiographs are needed to
Evaluate periodontal bone level
Panoramic, extraoral or occlusal radiographs are needed
For detecting or defining anomalies and pathological lesions outside the scope of periapical radiographs
Any tooth being suspected of being non vital needs to be
Tested for pulpal vitality
Two different types of pulp testing
Thermal and electric
Causes of loss of vitality
May be from bacterial causes from caries or perio disease.
Physical causes may be from mechanical or thermal injuries. Examples are from trauma, such as a blow, or dental procedures such as cavity prep or too rapid movement of ortho appliances.
Observations that suggest loss of vitality (clinical)
Discoloration of tooth.
Fracture.
Large various lesion or large restoration.
Fistula with opening into the oral cavity, over the apex of tooth.
Observations that suggest loss of vitality. (Radiographs)
Apical radiolucency.
Boneloss with widened PDL space extending to apex.
Fractured root.
Late various lesion or restoration that is close to pulp chamber.
Pulp testing is based on
Knowledge that a stimulus can create pain that a pt can respond to. The pulp tester determines the conduction of stimuli to the sensory receptors.
Vitality of the pulp depends on
The blood supply and not the nerve supply. For that reason the pulp test may not always show true condition of the pulp
Factors that influence a pts response to pulp test
Degree of pulpal degeneration or inflammation. Pain threshold. Reaction to pain. Nerve transmission blocks. Adjacent metal.
Responses to pulp test.
- No response: necrotic pulp
- Lingering pain after removing stimulus: irreversible pulpitis.
- pain subsides fast: reversible pulpitis
Thermal pulp testing
- cold test: may use cold drink, air blast, ice stick, ethyl chloride or cotton swab.
- heat test: warm temporary stopping. Warm to hot water.
Electrical pulp tester types.
- battery operated: portable, but can run down.
- plug in: more dependable.
Before performing pulp test you should
Review pts health history and consult with pts cardiologist prior to application if they have existing problems
Use precaution during pulp test with
Patients with a pacemaker or any electronic life-support. (Also precautions for cavitron, electrosurg., desensitizing equipment.)
Ameliogenesis imperfecta
Disorder of production and development of enamel
Avulsion
The tearing away or forcible separation of a structure or part. Tooth avulsion is the traumatic separation of tooth from alveolus
Bruxism
An oral habit of grinding, clenching or clamping the teeth; involuntary, rhythmic or spasmodic movements outside of chewing range; may damage teeth and attachment apparatus
Arrested caries
Various lesion that has become stationary and does not show a tendency to progress further, frequently has a hard surface and takes on a dark-brown or reddish color
Primary caries
Occurs on a surface not previously affected; also called initial caries; early lesion referred to as incipient caries
Rampant caries
Widespread formation of chalky white areas and incipient lesions that may increase in size over a comparatively short amount of time
Recurrent caries
Occurs on a surface adjacent to a restoration; may be a continuation of the original lesion; also called secondary caries
Succedaneous
The permanent teeth that erupt into the positions of exfoliated primary teeth
Etiology
The science or study of the cause of a disease or disorder
Enamel hypoplasia
Incomplete or defective formation of the enamel of either the primary or permanent teeth. The result may be an irregularity of tooth form color or surface
Idiopathic
Denoting a condition of unknown cause
