MA 2

Question 1

1-working length

2-where should the prep end

3-where is it located

4-old

5-minor apical diameter to apical foramen in youth

6-minor contriction distance from major foramen

7-reference pt

Answer 1

1-distance from coronal ref point to point where prep & obturation should end

2-the minor apical diameter (apical constriction)

3-based upon 2 measurements:

• the distance from apical foramen to apical constriction
• distance from radiographic apex to apical foramen

4-deposited w/ age at periapex, more as you get older

5-.5 in young

6-.59mm

—sooo .5 + .59= 1.09 working length kids
.7 +.59= 1.29 working length adults

7-site on occlusal/incisal surface where measurements are made—same pt used throughout canal prep & obturation
-must be stable (avoid undermined cusps) & must be easily visualized (incisal edge or reduced cusp tips & not use marginal ridge or floor)

Question 2

1-access cavity

2-cleaning &shaping pulp

3-straight line access

4-law of centrality

5-law of concentricity

6-radiographs

Answer 2

1-coronal opening to the center (pulp chamber) of a tooth
-required for effective cleaning, shaping, & obturation of pulp canals & chamber during endodontic therapy

2-must gain straight line access to apical constriction or curvature of canal but first must remove roof of pulp chamber & locate all root canal orifices & remove dental triangles

3-access to apical firament of the 1st curve in apical 3rd of canal

4-pulp chamber of every tooth is in the center of the tooth at level of CEJ

5-walls of pulp chamber are concentric to external outline of tooth at level of CEJ
via circumferential probing at the CEJ

6-pulp chamber size, depth & distance from occlusal table
vertical angulation of tooth

Question 3

access shapes

1-mandibular anteriors

2-max anteriors

3-mand & max premolars

4-mand molars

5-max molars

Answer 3

1-oval

2-central=triangular
lateral= ovoid
canine= oval

3-oval

4-trapezoidal

5-triangular

Question 4

1-bur for access

2-steps

3-law of color change

Answer 4

1-set bur in high speed just short of cusp tip-pulp floor distance

2-isolate via rubber dam, remove caries (restorability, gets rid of bacteria & temporary seal), advance bur until chamber of roof is penetrated…
place bur into roof opening and moving it laterally % parallel to long axis of tooth
wait until it is unroofed before looking for orifices so you dont gouge the floor or walls

3-color of pulp chamber is darker than surrounding walls

• walls are lighter= clear line of demarcation where light walls meet dark floor
• if not seen then overlying structure, reparative dentin of overlying pulp must be removed

Question 5

1-1st law of orifice

2-2nd law of orifice

3-3rd law of orifice

4-1st law of symmetry

5-2nd law of symmetry

Answer 5

1-orifices of canals always located at junction of walls & floor

2-orifices of canals always located at angles in the floor-wall junction

3-orifices of canals always located at terminus of roots development fusion lines

4-except for max molars, canal orifices are equidistant from line drawn mesio/disto across center of pulp chamber floor

5-except for max molars, canal orifices lie on line perp to line above line drawn mesio/disto across center of pulp chamber floor

Question 6

1-straight line access

2-taurodont

3-pulp chamber dimensions

4-2ndary dentin

Answer 6

1-remove dentin triangles by doing a brushing action from furcation/into triangle w/ an orifice opener rotary file

2-body of tooth & pulp chamber is enlarged vertically at expense of the roots

3-depend on history of tooth & age of patient

4-circumpulpal dentin
formed by normal pulp function after tooth formation is compelte
tubular pattern is regular
slower rate of deposition
abrupt changge in direction of tubules
causes dec in size of pulp chamber w/ age

Question 7

1-pulp horn

2-cervical pulp horns

3-weines classification

4-mand central & lateral incisor canals

5-mand canines

6-mand 1st premolar

7-mand 2nd premolar

8-mand 1st molar

9-mand 2nd molar

Answer 7

1-prolongation of pulp extending towards cusp of tooth
-late bell stage

2-never reported, cervical pulp horns—some pts the pulp is only 1.5-2.mm from external surface

• usually 1st & 2nd molars
• mesiobuccally

3-I am Me…You are Not
An I, A Y, Two I’s, An upside down Y

4-1 canal= 60% 2 canals =40%

5-1 root=95% 2 roots= 5%
type 1= 70% type 2=20% type 3=10%

6-1 root= 75% 2 roots=25%
type 1= 70% type 2= 4% type 3=25%

7-1 root= 97% 2 roots=3%
type 1= 86% type 1-2-1= 12% Type 4= 3%

8-mesial root= type 2=40% type 3=60%
distal root= type 1=70% type 2= 20% type 3=10%

9-mesial root: type 1=25% type 2=35% type 3=40%
distal root: type 1=92% type 2=5% type 3=3%

Question 8

1-max anterior teeth

2-max 1st premolar

3-accessory/lateral canals

40danger zone

Answer 8

1- 1 root & type 1 canal= 100%

2-1 root=25% 2 root=75%
type 1=9% type 2=13% type 3= 72%

3-channels of comm between the main body of root canal & periodontal ligament space

• along canal length & r. angles to main canal
• accesory= small canals in apical few mm & form apical delta
• develop bc of break in hertwigs epithelial rooth sheath during development (sheath grows around BV)
• can only be cleaned by effective irrigation w/ antimicrobials

4-middle 3rd

Question 9

1-apical third

2-smear layer

3-shaping

4-cleaning

Answer 9

1-radio apex, apical formane, apical constriction & CDJ

2-layer of microcrystalline & organic particle debris that is spread on root canal walls after root canal instrumentation

3-prep of canal to get a 3D hermetic filling of entire root canal length

• continuously tapering funnel fromm access cavity to apical foramen
• root canal prep maintains path of original canal
• apical formane should remain in orig psoition
• apical opening should be kept small
• done via rotary files & hand files

4-removal of organic & inorganic remnants w/in root canal system but not w/ only files, w/ files, irrigation, & intracanal medication

Question 10

1-idea irrigation

2-irrigants

Answer 10

1-able to disinfect dentin & tubulues
antibacterials
dissolve pulp tissue & inactivate endotoxins
remove smear layer
non antigenic, non toxic, & non carciongenic
-no adverse effects on dentin
-doesnt affect sealing ability of filling materials
-inexpensive & easy to apply
-no tooth discoloration

2-sodium hypochlorite, chlorhexidine, EDTA
sterile water, saline, H2O2, urea peroxide & iodine
no solution that meets all criteria
NaOCl=sodium hypochlorite= widely used

Question 11

1-sodium hypchlorite

2-NaOCl accidents

3-accident prevention

Answer 11

1-dissolves organic material, excellent microbial & effective lubricant

• inexpensive, easy to use & readily available
• but it has a high toxicity, doesnt dissolve inorganic matter, has foul taste & smell, corrodes metal & bleaches clothing

2-causes: binding/wedging the needle
-forceful irrigation—large apical foramen, apical resorption & immature apex
effects: immediate, severe pain
bleeding through canal
interstitial swelling
echymosis
possible infection

3-open coronal 3rd of canal
dont bind needle
passive irrigant delivery
oscillate needle up & down
stop irrigation if needle binds
side vented needle

Question 12

1-17% EDTA

2-2% chlorhexidine

Answer 12

1-chelating agent that dissolves inorganic matter of smear layer but doesnt dissolve organic matter of smear layer

2-broad spectrum antibacterial action

• sustained aciton & low toxicity
• lower cytotoxicity than NaOCl & lack of foul smell & bad taste
• cant dissolve organic substances & necrotic tissues & cant remove smear layer

Question 13

1-melanocytic lesions

2-non-melanocytic

Answer 13

1-ephelis
melanotic macule
peutz-jeghers
addisons
physiologic pigmentation
smoking associated melanosis
acquired melanocytic
blue nevus
melanoma

2-amalgam tattoo
drug induced pigmentation
heavy metal pigmentation

Question 14

1-Ephelis

2-melanotic macule

3-peutz jeghers syndrome

4-addisons disease

Answer 14

1-region of inc melanin production

• face, arms & back
• in fair-skinned, blue eyed, red/blonde hair
• diagnosis on clinical exam alone

2-flat, brown lesion bc of inc melanin
-well defined, solitary, tan/darkbrown, round/oval lesion

3-freckle like lesions of hands, mouth & peri-oral skin

• intestinal polyposis & predisposition for cancer
• oral lesions in 90% of ppl, vermillion zone, labial mucosa & tongue

4-insufficient production of adrenal corticosteroid

• pituitary dysfunction & destruction of adrenal cortex
• *-bronzing**- generalized hyperpigmentation of skin
• diffuse, brown macules of oral mucosa

Question 15

1-physiological pigmentation

2-smoking associated melanosis

3-acquired melanocytic nevus

4-giant hairy nevus

5-halo nevus

6-spitz nevus

Answer 15

1-symmetric & persistent pigmentation…in gingiva
-inc melanin

2-seen in about 20% of smokers, 1/2 pack a day

• females >males
• anterior gingiva
• pipe smoking w/ palate & buccal mucosa pigmentation…STOP SMOKING

3-malformation of skin & oral mucosa—mole

• proliferation of nevus cells, derived from neural crest
• before age 35 in whites
• nests of nevus cells in theques

4-hypertrichosis w/in congential nevus

5-halo is a result of nevus cells being destroyed by immune system

6-presents w/ red brown color in young patients

Question 16

1-blue nevus

2-melanoma

3-superficial spreading melanoma

4-nodular melanoma

5-lentigo maligna melanoma

6-acral mucosal melanoma

Answer 16

1-almost always in palate—2nd most common type
-proliferiation of cells deep in tissue

2-malig neoplasm of melanocytic origin

• damage from UV radiation= causative—acute exposure= greater importance than chronic
• fair skin/hair w/ tendancy to sunburn & get blistery
• family hx of it or hx of dysplastic or congential nevus
• middle aged white adults

3-macule w/ varying colors, represent 70% of cutaneous lesions

4-15% of skin melanomas…1/3 seen in head & neck area

5-10% cases…in older adults…very slow grow (15 yrs)

6-in blacks & orally

Question 17

1-oral melanoma

2-amalgam tattoo

3-drug-induced pigmentations

4-heavy metal pigmentation

Answer 17

1-patients in 60-70s, 66% cases involve men

• 80% affect palate or max alveolar ridge
• brown/black macule which become exophytic

2-traumatic implantation of amalgam in oral tissues

• bc failure to use RD, pieces in extraction sites, dental floss, endodontic retrofill, & high speed motor removal
• gingiva, alveolar buccal mucosa, tongue & palate
• black, blue or gray lesion
• 25% can be seen in xrays

3-stimulation of melanocytes & deposition of drug metabolites

4-exposure occurs via occupational exposure to vapors

• skin or oral deposits varying in color form gray to black
• lead/bismuth= blue-gray line alone gingival margin
• burtons line- lead intoxication
• argyria- chronic silver intoxication—grayish discoloration (sun areas)
• acrodynia- pink/swift—mercury intoxication—cold clammy skin w/ erythematous rash & pts are irritable
• gold- systemic allergic reaction= oral mucositis

Question 18

1-foundation restoration for endo treated tooth

2-all endo treated teeth

3-small holes in front teeth

4-restoration material

5-indications to place post

Answer 18

1-should maintain coronal & apical seal of RCT

• protect remaining tooth structure
• provide supportive & retentive foundation for placement of restoration

2-all of them need some type of permanent restoration of access prep
-but try to preserve tooth, posts require removal=bad

3-enough structure= bond restoration into place

4-strength: amalgam> composite> GI
but composite has most value for sealing RC fill & preventing microleakage (technique sensitive)

5-if both: remaining total tooth structure is inadequate for retention of foundation restoration

• sufficient root length to accommodate post while mainitaining adequate periapical seal
• be careful of lower incisors & max laterals

Question 19

1-cast gold post

2-titanium post

3-ceramic post

4-fiber reinforced polymer post

5-auxiliary pin placement

6-tapered post

7-parallel post

8-parallel threaded post

Answer 19

1-strong but 2 appts difficult to remove if fractured

2-fractures more readily

3-good strength—doesnt bond & hard to remove

4-carbon fiber surrounded by polymer matrix weaker, less root fracture easier to remove—modulus of elasticity close to dentin

5-preferable to placing 2 posts

6-least retentive—least tooth prep—mainly used

7-retentive—most tooth prep

8-most retentive—most root fractures

Question 20

1-length of post

2-cementation

3-analyze

4-failure

Answer 20

1-determined by leaving a min of 5 mm of GP in canal at apex

• post length should at least equal clinical crown length
• longer the post= more retentive=more able to fracture
• post diameter isnt important—inc width= inc chance of gracture rooth——-1 mm dentin circumferentially
• avoid screw posts except if short rooth—tighten 1/2

2-polycarb= microleakage= concern
resin= best to prevent microleakage, tech sensitive, remove ALL ZOE
GI= microleakage, poor bonding, weak---resin w/ GI= better

3-oral environment, occlusal stresses, amt of remaining structure & knowledge of various dental med

4-tooth structure fractures, dislodgment of restoration
leakage, or catastrophic fracture =ing extraction

Question 21

1-types of incisal fractures

2-etiology of fractured teeth

3-establish vitality

4-reattachment of tooth fragment

5-direct resin composite restoration

6-crowns

Answer 21

1-enamel only, enamel & dentin, pulpal involvement, & fracture below crest of bone

2-trauma, parafunctional habits, & carious lesions undermining incisal edge

3-traumatized teeth may/may not be vital

• positive= vital, lack= necrosis
• temporary lack of sensibility=pos traumatic pulpal healing

4-conservative, reproduce original contours & have fractured fragment

5-conservative, completed in 1 appt, multiple shades to get esthetics & build composite for contours

6-eliminates potential refracture

• crown is fabricated outside mouth—control over contours
• no discoloration
• not conservative—prep may be extensive

Question 22

1-treatment restoration of fractured teeth w/ direct resin

2-prep

3-beveled prep

Answer 22

1-occlusion, pumice teeth, shade selection, isolation, prep, bonding sequence, composite placement, finishing, check contours/contact/occlusion, & polishing

2-bevel, chamfer, stair step chamfer—
fracture resistance of a 1 mm bevel lower than for 2 mm bevel

3-should be at least 2 mm wide
bevel is in enamel
usually outline of bevel is irregular—blend & hide composite margin
-variety of burs can be used to create bevel(diamon & 8 flute)

Question 23

1-matrix

2-body opaque composites

3-microfill composite

4-translucent

5-black triangles

Answer 23

1-mylar—insert in the proximal under gingival w/ interproximal wedge can be placed

2-for dentin replacement

3-translucent & highly polishable—enamel replacement

4-gray composite used for enamel incisal edge translucency

5-proximal contact can be lengthened sometimes to minimize or eliminate black triangles