Random questions

Question 1

what happens if all teeth of 1 half of the dental arch are pulled out

Answer 1

the patient will eventually limp on the opposite side (meaning , if all right teeth were oulled out then he will limp on his left)

Question 2

ما الفرق بين التسمم و الانسمام و ما نتيجة كل منهما

Answer 2

التسمم هو ingestion of mercury for example will lead to loss of healthy teeth
اوا الانسمام هو شرب كيات قليلة على فترات زمنية طويلة for example fluorisis which results from excess ingestion of fluoride when the are forming which may disfigure or discolor the theeth

Question 3

what are the most teeth prone to congenital loss or disease

Answer 3

MAXILLARY lateral incisors either because of impefect amelogenisis( issue in enamel formation)or imperfect dentinogenisis . in the latter cases, tooth must be pulled out

Question 4

what is amelogenisis

Answer 4

Amelogenesis is the formation of enamel on teeth and begins when the crown is forming during the advanced bell stage of tooth development after dentinogenesis, forms a first layer of dentin. Although dentin must be present for enamel to be formed, ameloblasts must also be for dentinogenesis to continue.

Question 5

what are dental restorative materials

Answer 5

they arw used to prevent or repair damage to teeth caused by oral disease or trauma

Question 6

what are caries (tooth decay , tooth cavities)

Answer 6

the accumalation of bacterial plaque in areas of teeth where patient prophylaxis does not remove .

Question 7

what is prophylaxis

Answer 7

a medical term for proceduress that promote oral health

Question 8

what is periodontal disease

Answer 8

unlike caries, it affects the tissues surrounding the tooth like ( gingiva, periodontal ligament, cementum, alveolar bone)

Question 9

what is the difference between caries and periodontal disease

Answer 9

caries takes months to evolve while periodontal disease takes years, also caries affects the tooth itself whereas periodontal disease affects the tissues surrounding the tooh

Question 10

define edentulism (caused hy osteoporosis)

Answer 10

the complete loss of all natural dentition

Question 11

what are the teeth that are prone to be congenitally missing

Answer 11

maxillary lateral incisors

Question 12

when are endodontic restorative materials used

Answer 12

when pulpal or periapical tissues are damaged

Question 13

these restoration are generally small and used to repair minor trauma or caries

Answer 13

intracoronal restoration

Question 14

these restorations generally replace large portions of the external part of the tooth, because destruction of tooth is extensive and the is insufficient structure to retain intracoronal restoration

Answer 14

extracoronal restoration

Question 15

extracoronal preps nearly always must be restored using direct or indirect techniques

Answer 15

indirect techniques ( indirect restoration involves making a model of the prep them fabricating the restoration on the model from alloy, ceramic , or acrylic

Question 16

give 3examples of intracoronal direct restorations

Answer 16

amalgam, composite, and sealant restorations

Question 17

when is endodontic treatment necessary

Answer 17

if oral disease or trauma involves the pulp of the tooth

Question 18

what is used when infected pulpal tissue is removed

Answer 18

sealers that prevent ingress of bacteria, the filling material usually used is gutta percha

Question 19

clinical case where all natural dentition is lost

Answer 19

edentulism

Question 20

if one to four adjacent teeth have been lost, the function and esthetics of those teeth may restored using what

Answer 20

a fixed partial denture( aka bridge)

Question 21

how is a bridge classically prepared

Answer 21

placing extracoronal crowns on the abutment teeth

Question 22

what are the teeth adjacent to the edentulous space called

Answer 22

abutment teeth

Question 23

what are the artificial replacement teeth called

Answer 23

pontics

Question 24

what are pontics

Answer 24

they are artificial replacement teeth used in fixed partial dentures

Question 25

in the event that the abutment teeth are healthy what alternative technique can be used

Answer 25

Maryland bridge ( resin-bounded fixed partial denture)

Question 26

how does the maryland bridge differ from the classical bridge

Answer 26

the latter requires substantial sacrifice of abutment tooth structure unlike the Maryland bridge where extracoronal crown are not needed, instead the arms of th pontic are resin bounded lingually to the abutment teeth

Question 27

if multiple teeth are missing in multiple locations what technique is used

Answer 27

removable partial denture

Question 28

edentulism requires what

Answer 28

complete denture

Question 29

what is sorption

Answer 29

absorption and adsorption considered as a single process

Question 30

name 4 factors that influence what restorative materials to use

Answer 30

its effect on oral tissue possible toxic effects if ingested color optic qualities

Question 31

name the 5 properties of dental materials

Answer 31

``` dimensional change electrical properties solubility sorption mechanical properties ```

Question 32

why is dimensional change important during dental procedures such as prep of impressions or models

Answer 32

for the accuracy if dental restoration

Question 33

why is THERMAL dimensional change imp

Answer 33

restorative dental materials are subjected to tem changes in the mouth

Question 34

what is the linear thermal coefficient of expansion

Answer 34

is a measure of how much it expands per jnit length if heated one degree higher

Question 35

define percolation

Answer 35

is a way for bacteria to bypass your tooth's main layer of protection–the enamel–to attack it from within. By traveling along the dental filling, bacteria can reach your dentin. Dentin is actually porous, it has tiny tubules that lead right to the tooth pulp.

Question 36

why is percolation thought to be undesirable

Answer 36

because of the possible irritation of the dental pulp and recurrent decay

Question 37

name the dental material in which percolation decreases with time after insertion and why

Answer 37

dental amalgam, as a result of the space being filled with corrosion products from the amalgam

Question 38

thermal conductivity of the tooth

Answer 38

human enamel and dentin are POOR thermal conductors compared with gold alloys and amalgam ( although amalgam is substantially lower than gold) GIC bases closely replace lost tooth structure with respect to thermal conductivity

Question 39

why do we hse cements as thermal insulating bases in deep cavity preps

Answer 39

although dentin is a poor thermal conductor, a thin layer of it does not provide enough thermal insulation for the pulp unless a cement base is used under the metal restoration

Question 40

why dont composite restorations present a problem with thermal conductivity

Answer 40

because their thermal conductivity is similar to that of the tooth structure

Question 41

what are the two electrical prperties if dental materials that are of our interest

Answer 41

galvanism and corrosion

Question 42

Define galvanisim

Answer 42

is the generation of an electrical current in the patients mouth as a result of the presence of unsimilar metals in the mouth

Question 43

define an electrolyte

Answer 43

is is a liquid that contains ions (in our case it is saliva or oral fluids)

Question 44

crowns are made of alloys of which material that has a strong tendency to go into solution ( dissolve) and has an electrode potential of +1.33 V

Answer 44

aluminum

Question 45

what two restorations, that if came into contact inthe mouth cause the patient to feel pain and induces a metallic taste in the mouth

Answer 45

temporary aluminum alloy crown and a gold crown

Question 46

what kind of temp crowns are used to avoid galvanism and why

Answer 46

temporary POLYMER crowns, because they are poor electrical conductors

Question 47

Define corrosion, give an example state why

Answer 47

is the dissolution of metals in the mouth, Dental amalgam. because it reacts with chlorides and sulfides in the mouth which causes them to becom dull and discolored with time

Question 48

name the process in which polished amalgam becomes dull and discolored with time and why

Answer 48

TARNISH, because amalgam reacts with certain chem in the mouth such as chlorides and sulfides.

Question 49

Define absorption and give an example

Answer 49

is the uptake of liquid by the bulk solod; the equilibrium absorbtion kf water by acrylic polymers is in the range of 2 %

Question 50

Define adsorption and give an example

Answer 50

is the concentration of molecules at the surface of a solid or liquid ; the adsorption of components of saliva at the surface of the tooth

Question 51

why are zinc phosphate cements considered more soluble in the mouth than in lab tests waters indicate

Answer 51

because materials in the mouth are covered in plaque are exposed to various acids and organic materials

Question 52

define wettability

Answer 52

is a measure of the affinity of a liquid for a solid as indicated by spreading of a drop

Question 53

knowledge of what is esential in understanding the mech prop of dental materials

Answer 53

the magnitude of biting forces

Question 54

name the 5 types of stress that may occur when force is applied to a material

Answer 54

``` compression tensile shear bending moment twisting moment ```

Question 55

what is the difference between compression and tensile stress

Answer 55

compression is when a material is squeezed while tensile stress is when a material is pulled apart

Question 56

define strain

Answer 56

strain is the change in length or the deformation per unit length

Question 57

define preventive materials and give 3 examples

Answer 57

are dental materials designed to prevent disease or injury to the teeth and supporting tissues. flouride gels, pits and fissure sealants, mouth protectors

Question 58

what is the importance of fluoride ion

Answer 58

its effectiveness in reducing the incidence of dental caries

Question 59

etchants are generally composed of what

Answer 59

37% of phosphoric acid in water

Question 60

etchants are generally composed of what

Answer 60

37% of phosphoric acid in water

Question 61

which step is critical to the success of the sealant and why

Answer 61

drying the washed tooth for 15 seconds, because moisture interferes with the retention of the sealant by the fissure

Question 62

what are the steps of manipulating sealants that must be followed sequentially

Answer 62

cleansing and etching the occlusal surface, washing these areas, DRYING THEM, applying the sealant to the pit and fissure, polymerizing and finishing.

Question 63

what is the concentration of fluoride in a typical commercial acidulated phosphate fluoride gel

Answer 63

1.22 to 1.32 %

Question 64

why containers in which the sealants are supplied must be closed tightly

Answer 64

to minimize the evaporation of volatile monomers which would cause the sealant to become more viscous

Question 65

what are the main cariogenic bacteria

Answer 65

Streptococci and lactobacilli