Miscellaneous

Question 1

when does pre prosthetic surgery take place

Answer 1

before the fabrication of a denture

Question 2

what is included in pre prosthetic surgery

Answer 2

• maxillary and mandibular tori
• exostoses
• sharp prominents mylohyoid ridges
• epulis fissuratum

Question 3

what is denture stomatitis

Answer 3

a localized or generalized chronic inflammation of the denture bearing mucosa

Question 4

what is the clinical presentation of denture stomatitis

Answer 4

redness and a burning sensation with or without discomfort

Question 5

what is the most likely cause of denture stomatitis

Answer 5

trauma and secondary fungal infection

Question 6

what is the treatment of denture stomatitis

Answer 6

• improved oral hygieve
• tissue rest
• antifungal therapy
• resilient tissue conditioners
• new, well fitting denures

Question 7

acute atrophic candiasis presents as:

Answer 7

• a red patch or atrophic or
• erythematour red and painful mucosa

Question 8

antibiotic sore mouth, a common form of atrophic candidiasis should be suspected on a patient that develops symptoms of:

Answer 8

• oral burning
• bad taste
• sore throat during or after therapy with broad spectrum antibiotics

Question 9

what patients are susceptible to atrophic candidiasis

Answer 9

• chronic iron deficiency anemia

Question 10

what kind of candidiasis is denture stomatitis

Answer 10

chronic atrophic candidiasis

Question 11

where is papillary hyperplasia found

Answer 11

in the palatal vault

Question 12

what are the causes of papillary hyperplasia

Answer 12

• poor fitting dentures
• poor oral hygiene
• leaving denture in 24 hours a day

Question 13

what is the treatment for papillary hyperplasia

Answer 13

• educate pt on OH
• advise patient to leave denture out at night
• soak dentures for 30 minutes in a 1% solution of sodium hypochlorite and rinse thoroughly
• use tissue conditioners
• patient should brush irritated area lightly with a soft brush

Question 14

what is epulis fissuratum

Answer 14

a chroniccally ill fitting denture causes inflammatory fibrous hyperplasia adjacent to its border
- reactive growth in relation to an overextended or ill fitting denture flange

Question 15

what are the causes of epulid fissuratum

Answer 15

• long term neglect or settling subsequent to residual ridge resorption
• traumatic occlusion of natrual teeth opposing an artificial denture

Question 16

what is the treatment of epulis fissuratum

Answer 16

surgical removal of the hyperplastic tissue

Question 17

what is the treatment for hyperplastic tissue

Answer 17

• tissue rest
• soft reline of existing dentures
• change in denture habits- not wearing them 24 hours a day
• surgical removal of the tissue

Question 18

what is the best impression technique for a patient with loose hyperplastic tissue

Answer 18

to register the tissue in its passive position

Question 19

what is the most important reason for treatment of hyperplastic tissue before construction of a denture

Answer 19

to provide a firm, stable base for the denture

Question 20

what is Kelly’s combination syndrome

Answer 20

a specific pattern of bone resorption in the anterior portion of edentulous maxilla

Question 21

when does kelly’s combination syndrome happen

Answer 21

when a mandibular partial denture is opposed by a maxillary complete denture

Question 22

what is the cause of kelly’s combination syndrome

Answer 22

• prostheses lose some degree of support as a result of alveolar resorption
• as resorption occurs under mandibular extension bases support for the posterior prosthetic teeth is decreased
• the occlusal forces are concentrated within the anterior sextants, increases forces in anterior maxilla may result in absorption, downward growth of the tuberosities and tipping of the occlusal plane

Question 23

how is kelly’s combination syndrome treated and how does this fix the issue

Answer 23

• continuous reline or placement of implants in mandibular posterior locations
• this results in more stable occlusal plane and a more equitable distribution of forces to the maxillary denture

Question 24

what is tissue conditioner

Answer 24

soft materials that are applied to the intaglio surface of a complete or partial denture to allow a more equitable distribution of forces throughout the dental arch
- non- irritating
- non-toxic
- soft, elastic does not undergo permanent deformation

Question 25

what are tissue conditioners used to treat

Answer 25

unhealthy or abused oral tissues

Question 26

how long does the softness of tissue conditioner last

Answer 26

about 1 week which then can become hard and an irritant

Question 27

how often must the tissue conditioner be changed

Answer 27

every 3-5 days

Question 28

what is tissue conditioner made of

Answer 28

- powder and liquid - powder is an acrylic polymer, usually ethyl methacrylate - the liquid is usually a mixture of ethyl alcohol and aromatic ester - the two combine to form a gel that remains pliable for several days

Question 29

what is the mechanism of action of tissue conditioner

Answer 29

a combination of improved force distribution and a short term cushioning effect

Question 30

the intaglio surface of the RPD is checked using:

Answer 30

pressure indicating paste

Question 31

when is tissue conditioner applied

Answer 31

after intaglio surface is checked with PIP and occlusion is checked normally

Question 32

how is tissue conditioner applied

Answer 32

- the cameo surface of the prosthesis is painted with separator - after the tissue conditioner is mixed, flowed onto the intaglio surface of denture - tissue conditioner distributed evenly using a small spatula - denture is seated in the mouth under light pressure - pressure is maintained - border tissues should be manipulated to border mold the conditioner

Question 33

for a mandibular RPD, the tongue should be brought:

Answer 33

forward and forcibly placed into each cheek to define the lingual extension accurately

Question 34

with tissue conditioner if posterior artifical teeth are present:

Answer 34

patient must close the teeth together while the conditioner is still flowable to align the artifiial teeth properly with the opposing occlusion

Question 35

how long should the patient sit with tissue conditioner under the gel stage has been reached

Answer 35

4-5 minutes

Question 36

excess tissue conditioner should be removed using:

Answer 36

a sharp blade

Question 37

areas of contact in tissue conditioner should be removed using:

Answer 37

laborator burs

Question 38

what should you do with dentures out of the mouth with tissue conditioner on it

Answer 38

- do not let it dry - submerge in water or a cleansing solution

Question 39

how is wrought wire made

Answer 39

drawing the metal from which it is made into a wire

Question 40

wrought wire clasp must have an elongation percentage of:_________ and why?

Answer 40

more than 6% to allow the clasp to bend without microstructure changes that could compromise its physical properties such as fracture

Question 41

what is cast metal

Answer 41

any metal that is melted and cast into a mold

Question 42

what is a wrought metal

Answer 42

when casting is cold-worked in some manner to provide the required article or appliance

Question 43

which have better mechanical properties: wrought wire or cast structure

Answer 43

wrought wire

Question 44

the wrought wire has ___greater ________ than the cast alloy from which it was fabricated

Answer 44

25%; strength, hardness and tensile strength

Question 45

the wrought wire has greater _______ than the cast clasps and are ______ than cast clasps

Answer 45

flexibility and adjustability; tougher and more ductile

Question 46

what does the success of wrought wire clasps depend on

Answer 46

their physical properties and the changes that may occur during fabrication

Question 47

laboratory procedures can compromise desirable physical properties of wrought wire due to:

Answer 47

improper heating and cooling

Question 48

what is the mechansim of action of lab errors in fabricating wrought wire

Answer 48

- too much heat - change in the fibrous microstructure of the wrought wire and getting replaced by a grain or crystalline mcirostructure - process is known as recrystallization or grain growth

Question 49

what is the most undesirbale occurrence in wrought wire retentive arms

Answer 49

recrystallizatino or grain growth

Question 50

the popularity of chromium Cobalt alloys for fabrication of cast frameworks for RPDs has been attributed to their:

Answer 50

- low density (weight) - high modulus of elasticity (stiffness) - low material cost - resistance to tarnish

Question 51

chromium cobalt allows are ____ in comparison to gold or pallidum alloys

Answer 51

more rigid

Question 52

how can the stiffness of chromium- cobalt allows be overcome

Answer 52

by including wrought- wire retentive elements in the framework

Question 53

what does chromium, coblat, and nickel do in chromium alloys for RPDs

Answer 53

- chromium: ensures that the allow will resist tarnish and corrosion due to formation of a complex chromium oxide film - cobalt: contributes strength, rigidness and hardness - nickel: increases ductility

Question 54

what are the minor constituents and their effects on chromium alloys for RPDs

Answer 54

- carbon: effect on strength, hardness and ductility - tin, indium: improve bonding

Question 55

the gold allows are _____ as flexible as the chromium- cobalt alloys

Answer 55

twice

Question 56

what are the advantages of chromium cobalt alloys

Answer 56

- high modulus of elasticity and therefore lower flexibility - low material cost - low density (weight)

Question 57

what are the possible causes of failure of chromium cobalt alloys

Answer 57

- cold working - shrinkage porosity - low percent elongation - excessive carbon in the alloy

Question 58

why does cold working cause failure of chromium cobalt alloys

Answer 58

reduces the percentage of elongation that causes a decrease in hardness

Question 59

why does shrinkage porosity cause failure of chromium cobalt alloys

Answer 59

the alloys shrink about 2.3% and the result is porosity

Question 60

why does low percent elongation cause failure of chromium cobalt alloys

Answer 60

directly related to greater brittleness

Question 61

why does excessive carbon in the alloy cause failure of chromium cobalt alloys

Answer 61

reacts with the other constituents to form carbides