Restorative

Question 1

OPT & discuss iatrogenic / developmental / trauma faults in dentition

Answer 1

iatrogenic -
RCT; # file, perforated file, ledging, GP over/underfilled, extruded sealer, missing canal
restorations; overhangs, #, poor margins, post without RCT, perforated post
resorption; external inflammatory, surface, replacement, internal inflammatory, cervical root resorption
developmental -
cysts; dentigerous, radicular, erupted, keratocyst
unerupted / impacted / impacted teeth
dentinogenesis imperfecta; amber radiolucency, bulbous crown, abscess, pulpal obliteration
TMD
trauma -
bone #, tooth #, displacement

Question 2

facebow to register occlusion

Answer 2

1. reference points representing frankfort plane;
   - external auditory meatus (EAM)
   - anterior reference point 43mm from incisal edge of lateral incisor 12/22 marked on pt
2. attach transfer jig to bow & tighten score ensuring numbers facing operator
3. apply bite reg medium (wax / PVS) onto bite form & register maxilla bite
4. once bite is recorded & accurate attach bite fork to transfer jig through hole next to no2 on jig
5. position the bow earbuds into EAM; pull upwards & make sure bow is centred & tighten screw
6. slide bow & jig up and down to align with reference point on infra orbital foramen on the cheek below the eye & then tighten screw 1 and then 2
7. unscrew transfer jig from bow & then unscrew bows centre wheel & remove from pts ears
8. remove from pts mouth & disinfect for sending to lab

Question 3

toothache; unrestorable 26 requiring XLA explain findings to pt who is on warfarin

Answer 3

• introduce self & designation
• gather info re pt coagulation status; ask re INR, when it was last done and what the value was
• ask to see pt INR (yellow) book
• detailed & valid explanation as to why the tooth cannot be XLA today with no jargon; due to high bleeding risk as a result of warfarin & inr values above recommended level for safe xla
• refer to relevant guidelines i.e. SDCEP where INR should have been taken ideally within 24hrs, 72hrs if stable (stable = INR <4 for last 3mths) & proceed with tx without interrupting medication if INR <4
• convincing pt & not proceeding with xla
• deal with pt pain; acknowledge pt is in pain & discuss what you can do today i.e. analgesia +/- pulp extirpation & dressing
• ask if pt understands & if they have any qs

Question 4

11 veneer prep

Answer 4

all burs given
remember ppe
points for seating position
x2 putty index; 1 for temp & 1 for reduction (section along long axis)
use chamfer bur to:
- create 3 notches on buccal surface, each just below 0.5mm into tooth tissue
- ensure tooth cut in 2 planes as for crown prep
- connect notches with chamfer bur
reduce level of incisal edge approx 1mm
bevel incisal edge (3 different planes total)
use comp finishing bur i.e. rugby ball to smooth

Question 5

cavity prep 14MO

Answer 5

remove artificial caries with high & slow speed burs
avoid damage to adjacent teeth
CSMA
no sharp line angles
no excessive prep
make sure cavity margins not at contact point / clear contact

Question 6

rubber dam placement 35 MOD

Answer 6

select correct clamp:
anteriors C / E
premolars E / EW
molars A / AW / FW / K
can use nurse for assistance
place dam 36-34 due to contacts
use wedgets & floss ligatures
remember to floss clamp
need correct clamp, correct no of holes, ligature, wedgets, frame on outside of dam, efficiency

Question 7

bridge prescription for conventional cantilever

Answer 7

details - pt stick on all 3 sheets, practitioner details etc, date & time of recording imp, date & time of completed required lab work, plan stage of tx (prep or fit) present (work), other lab work
instructions - please pour imps with 100% improved stone, mount on semi adjustable articulator using facebow / wax bite provided, construct metal ceramic NiCr conventional mesial cantilever bridge to replace tooth XX using XX as abutment & XX as pontic in shade Y. staining & special effects surface features & finish
ridge lap pontic (depends on tooth to be replaced)
ridge lap = posterior
modified ridge lap = upper anterior
dome shape = posterior / lower anterior
please construct in canine guidance & ensure pontic is free of excursive movements
please return bridge with cast

Question 8

GSC, MCC, porcelain crown, porcelain veneer, adhesive cantilever bridge; what cements used for each & what to check prior to cementing

Answer 8

1. aquacem (GIC) - metal post, MCC, gold, zirconia
2. panavia (anaerobic cure comp) - adhesive bridge (RBB)
3. nexus (dual cure comp) - fibre post, comp/porcelain rests, veneers

pre cementation checks;
1. check on cast
- is it what was asked for
- correct pt
- rocking, M/D contacts, marginal integrity, aesthetics
- check contact points on adjacent teeth on cast to ensure not damaged i.e. when prepped tooth sawn off to be invested
- occlusal interference on excursions
- natural teeth contacting; check with shimstock 8um
2. remove crown from cast
- check occlusion correct & still the same
- check crown thickness using callipers
3. crown placed in pt with airway protection
- check all above
- check pt happy with appearance
4. post cementation checks
- excess cement removed
- no space around margins
- IP contact point exists & is clear
- occlusion checked with articulating paper & in excursion as well
- restoration cleansable
- confirm pt happy with aesthetics & feel

Question 9

txp for 35yo male; smoker, alcohol, acid erosion / NCTSL, perio disease & impacted 8s

Answer 9

immediate - pain (pericoronitis / toothache / perio abscess / PAP)
initial -
HPT; diet advice inc erosion, consider medical referral if GI intrinsic acid, smoking cessation, alcohol advice, supra & sub pmpr
removal of non symptomatic teeth of poor prognosis i.e. impacted 8s; inform of risks - pain, bleeding, swelling, bruising, numbness / altered sensation that can be temp or permanent, infection, dry socket
NCTSL; find cause is it diet, alcohol, meds, mh, habit, parafunction tx = diet diary, study casts, photos, DBA, GI, comp. fluoride, dietary advice to change habits i.e. don’t swirl drink around mouth, use straw, avoid sports gels, drinks, fizzy juice, use milk / water, chew gum, snack on cheese & breadsticks, desensitising agents i.e. stannous fluoride, potassium nitrate for symptomatic relief
caries mx
endo tx; temp rests
reevaluation
bsp step 3 if pt motivated & NCTSL pics & casts
reconstructive
filling spaces, denture, bridge implant etc
maintenance
perio & NCTSL

Question 10

gold crown fitted onto mounted casts, use articulating paper, shimstock & callipers to assess crown. make decision to redo prep & send back to lab

Answer 10

is this the correct rest for pt and what was asked for

check on cast
- rocking, m/d contacts, marginal integrity, aesthetics
- check contacts on adjacent teeth incase damaged when sectioned
- occlusal interference on excursions
- no natural teeth contacting; checked with shimstock 8um
- inadequate reduction on DL cusp

remove crown from cast
- check is natural teeth occlude properly now
- check if tooth is under prepped
- measure crown thickness using callipers; minimum 0.5mm circumferential & minimum 1.5mm for functional cusps (1mm for non functional)

mx
- check amount of interference by dropping incisal pin & calculate the difference; if doable to reduce crown without making it too think then adjust & cement
- if above not possible redo prep & send back to lab. follow crown principles; ideal taper 6o, retentive grooves/slots, bevel functional cusps, 2 place buccal reduction, smooth prep margins at gingival margin

avoiding fault in future
- measure temp crown thickness prior to cementing
- use sectioned putty matrix index when prepping

Question 11

IV sedation. O2 dissociation curve, max N2O%, alarms & what to do if it goes off, contraindications

Answer 11

normal O2 saturation = 97-100, alarm goes off at 90 & hypoxic at 85
if dropping stimulate pt by asking them to breathe
if alarm - supplemental O2; nasal cannulation 2L/min & reverse with flumazenil 500mg/5ml

CI for IV - severe COPD, hepatic insufficiency, pregnancy & lactation, hypothyroidism, myasthenia gravis

CI for IS - common cold, tonsilitis, nasal blockage, severe COPD, MS, pregnancy (1st trimester), claustrophobia

minimum O2 delivery = 30% (max N2O = 70%)

Question 12

pt to begin chemo for breast cancer explain relevance of dental health for cancer tx, dx condition of grossly carious tooth & proposed mx

Answer 12

talk about getting dentally fit, improving OHI, looking after oral health
chemo puts toll on whole body inc mouth
GDP attempt to reduce complications in chemo regime to avoid interruption to chem, remove potential sources of infection, avoid exacerbation of mucositis

tx to be carried out
full mouth pmpr
remove anything with poor prognosis or areas of infection normaly xla need x10 days to heal, should not be done during chemo due to high risk of infection / ORN & if done after chemo higher risk of infection, slower healing & risk of MRONJ, imp for soft splint & smooth sharp teeth

diet / OHI / fluoride

mid tx mx
- minimal role unless emergency +/- pathology
- mucositis; general avoid smoking, spirits, spicy food, tea, non prescription medicine // topical; oral colling prior to therapy, ice, topical lidocaine, saline, sodium bicarbonate, benzydamine HCl, gelclair, caphasol, tea tree oil mw, for pseudomembranous candidosis give antifungals

post tx palliative care
maintenance of OH & diet, prevention, more frequent monitoring, MRONJ risk, altered taste, dry mouth, decreased salivary flow 50-60% in 1st week, further 20% in next 5-6wks, change in salivary consistency & character i.e. increased viscosity & decreased pH, change in taste perception, recovery over period of yrs will not return to normal, associated problems dysphagia, dysarthria, dyspepsia, quality of life, increased risk of perio caries candida sialadenitis, pros difficulties