Restorative Flashcards
Crown Critique - Gold crown fitted onto mounted casts (6 mins)
Use articulating paper, shimstock and calipers to assess crown
Make decision to redo prep and send back to lab
● Pre-cementation checks
○ Is it the restoration as asked for?
○ Check on the cast
■ Rocking, M/D contact points, marginal integrity, aesthetics
■ Check contact points on adjacent teeth on cast to ensure not damaged
● Can be damaged when prepped tooth is sawn off the cast to invest
■ Occlusal interference on excursions
■ No natural teeth contacting (checked with shimstock 8μm)
■ Inadequate reduction DL cusp
○ Remove crown from cast
■ Check if the natural teeth occlude properly now
■ Check if tooth is under-prepped
■ Measure crown thickness using calipers
● Minimum 0.5mm circumferential
● Minimum 1.5mm for functional cusps (1.0mm for non-functional)
● Management
○ Check amount of interference by dropping incisal pin and calculate the difference
■ If do-able to reduce crown without making it too thin then adjust and cement, otherwise…
○ Re-do prep and send back to lab
■ Follow crown prep principles: Ideal taper 6o, retentive grooves/slots, bevel functional cusps, two plane buccal reduction, smooth prep margin at gingival margin
● Avoiding fault in future
○ Measure temp crown thickness before cementing
○ Use sectioned putty index when prepping
. Dental Dam Placement 13 to 23 (6 mins)
Please isolate teeth 13-23 and secure with wedjets distally. Please place floss ligatures on tooth 11 and 21
● Template: use a pen to identify holes
● Place opaldam - test the dam with CHX?
● Don’t cover nose!
. Lower Co/Cr Denture Design (6 mins)
Please design a lower Co/Cr denture - Kennedy Class II Mod 1
Teeth present: 34, 33, 32, 31, 41, 42, 43, 44, 47
● Kennedy classification
○ I: Bilateral free-end saddles
○ II: Unilateral free-end saddles
○ III: Unilateral bounded saddles
○ IV: anterior bounded saddle only
■ Any additional saddles: modifications (except class IV) e.g. class I modification 1 has a bilateral free-end saddles and an anterior saddle
● Craddock classification
○ Class I: tooth
■ Bounded saddles <4 teeth, occlusal and cingulum rests
○ Class II: mucosa
■ Free end saddles: RPI systems, utilised when no suitable teeth available
○ Class III: tooth and mucosa
■ Bounded saddles >4 teeth
● Support
○ Rests: (NB: can prepare rest seats)
○ Immediately adjacent to bounded saddles
○ Mesially to free end saddles
○ Consider opposing arch: is there space for this?
● Retention
○ Clasps: (direct) (NB: composite resin can be added)
■ Use three clasps as far away from each other as possible
■ Types:
● Occlusally approaching: three-armed clasp (retentive arm, reciprocal arm and occlusal rest), ring clasp and
● Gingivally approaching: I-bar, T clasps
○ Other: guide planes (how its seated), soft tissue undercuts, precision attachments
○ Indirect:
■ To place components so as to resist ‘rocking of denture around direct retainers
■ Not needed if three clasps present: provide stability in free end saddles and very long bounded saddles
■ If only two clasps: Place a supporting element to the opposite side of the clasp axis than the origin of the displacing force (90o to the clasp axis and as far away as possible)
● Connector
○ Upper:
■ Plates: Palatal plate, anterior plate, mid-palatal plate, horseshoe plate
■ Bars: Posterior bar, Horseshoe bar, anterior and posterior bar (ring)
○ Lower:
■ Bars: Lingual bar (8mm space = 3mm ging, 4mm bar, 1mm depth FOM), lingual bar w/ dental bar, dental bar, sublingual bar, labial bar
■ Plate: lingual plate
Direct Pulp Cap: assume dam placed, tooth with cavity close to pulp (12 mins)
Assuming dental dam has been applied, please place a direct pulp cap on an exposed 36 following a pulpal exposure on the mesial axial wall.
● Explain to pt: pulp exposed and requires pulp cap (explain what is)
○ Likely no actor so no need
○ Address the need: vital therapy and risk of possible death of pulp which requires RCT
● Tooth must be asymptomatic, vital, no history of pulpitis (e.g. prolonged pain, toothache)
○ Pulp exposure must be small and surrounding dentine must be relatively hard - otherwise extripate
● Dam should have been on before the pulp was exposed - saliva contamination must be avoided.
● Haemorrhage from exposed pulp - copious irrigation with sterile saline (arrest bleeding with saline)
● Cavity irrigated with chlorhexidine (0.2%) (Clean with CHX, after bleeding arrested)
● Cavity is blotted dry using sterile cotton wool pledgets. (Do not air dry)
● Exposed pulp covered with hard-setting calcium hydroxide cement (Dycal or Life)
● RMGI lining placed (Vitrebond) and the restoration completed as planned.
● Continuing vitality monitored: if symptomatic RCT required.
Carious pulp exposure:
● Dam already placed
● Extirpation - Pulpectomy
○ Coronal pulp tissue removed with sterile spoon excavator, irrigated with saline and dried.
● Discuss with pt that RCT or XLA will be required.
● Odontopaste/Ledermix (antibiotic/steroid agent) as palliative agent in anticipation of RCT/XLA
● Cotton wool roll + GIC restoration.
2 Indirect pulp cap:
● Cleanse cavity with 0.2% w/w chlorhexidine.
● Stained firm dentine is left in situ and covered with a setting calcium hydroxide cement (Dycal or Life).
● A stronger lining material is placed (RMGIC – Vitrebond) to protect the Ca(OH)2 and the tooth is restored with a provisional restoration (GI or RMGI).
● The tooth must be vital, asymptomatic and have no history of previous pulpitis.
● The tooth is monitored for 3 months and if vital and asymptomatic, the provisional restoration should be removed, stained dentine carefully excavated and definitive restoration placed.
● If there have been any pulpal symptoms, then RCT should be undertaken.
A 27-year old teacher presents with a bunch of E/O and I/O signs of TMD. Click on both sides, sore muscles, sore in morning, tongue scalloping and cheek biting (linea alba). Please discuss the diagnosis with the patient, and conservative management for this condition. You do not need to obtain further information from the patient.
● Diagnosis:
○ ‘Mrs Smith, you have a very common condition, in fact around 75% of the population get it at one point in their life. …. It is called temporomandibular disorder, or TMD …’
● Explanation:
○ ‘The jaw joint sits in base of skull and muscles control opening and closing. Now, like any muscle in the body, if overworked they get tired e.g. if you climb a mountain legs are sore for next few days.’
○ ‘However, as your jaw joint gets used all day everyday like for speaking and eating it never gets a rest. Muscles become inflamed and sore.’
○ ‘The fact that you’re sore in the morning also tells us that you clench or grind your teeth at night as well which puts more stress on those muscles and exacerbates the problem even more’
○ ‘The clicking by your ear is caused when the disc between your jaw and the skull gets trapped in front of the jaw bones and snaps in place’
○ Could draw a wee diagram to show disc and explain that when muscles not in harmony the disc is pulled at wrong time to create clicking noise or disc trapped in front of jaw bones crushing the tissue that can cause pain.
● Management:
○ Reassurance! - “The way we manage this is very simple’
○ ‘It involves resting the joints’
■ soft foods/cut in small pieces, chewing on both sides, avoid chewy foods/gum, avoid wide opening, avoid stifling yawns, avoid grinding during day, avoid habits (biting nails)
○ Conservative advice including analgesia (paracetamol/ibuprofen) and heat packs.
○ Evidence to show yoga helps and general stress reduction is beneficial.
○ Make splint to break nocturnal habits
● Summary
○ Reassurance - common condition with simple conservative management
○ Important to reduce stress
○ Inform that other symptoms like tongue scalloping and linea alba are caused by the clenching and also go away on management of condition.
○ Ask if any questions
○ Actor marks for communication, simplicity of language and empathy.
Charting - Communication with nurse while charting and checking her charting (6 mins)
Please work with your nurse to chart the dentition present (in the mannequin head).
● Look carefully for buccal restorations!
A 28-year old female patient who works in television has had an accident in which she injured her face. There are no other injuries and you have completed the examination as well as taken a radiograph. You have diagnosed the tooth as having a vertical root fracture and is unrestorable.
Explain your findings to the patient and how you would treat them.
Overview of marks:
- Student listens and is empathetic
- Asks patient what patient is expecting outlook to be or what they want from appointment
- Asks permission to continue findings
- Break news slowly in chunks
- Avoids jargon, or explains if used
- Allows patient time to take in information and gives chance to ask questions
- Repeats the news
- Summarises what they’ve said
- Gives patient replacement options
- Actor asked if they understood, been shown empathy
● Setting:
○ Sitting down at same level as them
○ Try to make them as comfortable as possible
● Perceptions:
○ What does the patient understand has happened up until now?
■ ‘Are you aware of what might be wrong?’
○ What is patient expecting from appointment?
● Information:
○ Inform patient that you would like to discuss the prognosis of the tooth
○ Ask them if they would like to discuss that…they’ll say yes
● Knowledge
○ Give a warning shot
■ ‘I wish I had better news’
■ ‘I’m afraid the news are not good’ …. pause for a bit
○ Give them the knowledge of what you know
■ ‘Your tooth is unrestorable and requires to be extracted’ …big pause…
○ Let it sink in and let them dictate the pace of the conversation from here
■ They might want to know loads of info really quickly or they might be in shock
■ Give them chance to ask questions
● Empathy:
○ Words to the effect of
■ ‘I am deeply sorry to break this to you’
■ ‘I understand this must be hard for you’
● Summary and close:
○ Repeat the news
○ Summarise what you’ve told them and the plan for going forward
■ ‘We will aim to restore this tooth as soon as possible for you’
■ Immediate options:
● Immediate denture in the short term then extraction
● Bridge using their own sectioned crown if available
● Direct polycarbonate crown bridge
■ Permanent replacement options:
● Bridge, Denture, Implant (need 3 months for bone around XLA socket to stabilise)
■ Do NOT mention unrealistic interventions - assess by case
○ Ask of any questions they might have
○ Ensure the patient has a clear plan of what will happen next and your roles
○ Offer them a follow-up appointment or phone number for any questions
Complete Denture Faults (6 mins)
C/C (fractured?) denture provided. Please identify 6 faults with this denture and how to rectify these.
● Anterior flange missing:
○ Remove undercuts, build flange with greenstick and reline
○ Rebase if not possible or remake if necessary
● Midline Diastema:
○ If want to keep physical aspects of denture, but change aesthetic only
■ Replica (2 stage putty around denture, vaseline to separate)
■ Wax replica used for functional impression + jaw registration
■ Ask lab to close diastema for tooth trial stage
○ Remake if other problems
● Underextended posteriorly at tuberosities:
○ Reline: if functionally good and only problem
○ Remake: if everything bad
● Locked occlusion:
○ Remake with replica technique and use cuspless teeth
● Base plate too thin:
○ Rebase thicker or Rebase using high impact resin. Or remake
● Tori:
○ Relieve clinically if only problem or ask for tin-foil relief
○ If too thin or other problems: rebase or remake and ensure lab waxes undercuts
● Tooth position wrong:
○ Remake
● Occlusal table too long - ie too many posterior teeth over the tuberosities:
○ Remove posterior teeth/ grind down - or remake
Denture Fracture Faults
● Fracture prone features:
○ Thin, under-extended and or absent flanges (open-faced)
○ Previous repairs
○ Stress concentrators - eg. a large fraenal notch, midline diastema, foreign particles
○ Poor fit
○ Lack of adequate relief
○ Tooth wear
● Prevention:
○ Inclusion of a metal palate
○ Use of an alternative denture base material such as a high impact acrylic resin for thin underextended flanges or open faced denture
● Fracture repair:
○ For simple midline fracture, two fragments are secured in position with sticky wax and additional reinforcement e.g. wooden sticks across the line of fracture. Sent to the lab - light cured PMMA is normally used because of its easier processing technique but it is weaker than heat cured PMMA.
○ If denture fractured into multiple fragments, it may be necessary to reposition the larger of the fragments intraorally and to take an in situ overall impression in alginate. If not possible – remake.
○ For repair of fractured or missing teeth, an impression of the opposing dentition and/or the denture is required to ascertain the correct occlusal relationship.
11d cavity
● Go palatally if possible
● Avoid damage to the adjacent teeth
○ leave a thin layer of enamel when prep-ing cavity, controlled break towards the end
● Make sure cavity margins not at contact point/clear contact
Denture design - Articulator Identification, Reciprocation, Bracing (6 mins)
● Examiner asks: What kind of articulator are these casts mounted on?
○ Average value (1 mark)
■ Also: simple hinge, semi adjustable and fully adjustable
● Upper design (2 marks) & Lower design (2 marks)
○ Design correctly and neatly copied.
○ Rests, major connectors, saddle areas and clasps all drawn correctly onto prescription
● Lab prescription supplied
○ Position of all 8 occlusal rest seats identified (4 marks)
○ 4 I-bars correctly identified (2 marks)
○ 2 occlusally approaching and 2 ring clasps identified (2 marks)
○ Mid palatal strap and lingual bar (2 marks)
● Area providing reciprocation
○ Reciprocation is provided by any part of the denture that is directly opposite a clasp arm.
○ Resist lateral movement of teeth from forces of clasps/retentive component during insertion.
○ Should indicate all 8 areas (2 marks)
● Indicate what bracing is and what parts of denture provide bracing
○ Bracing is the resistance to lateral movements (1 mark)
○ Correctly identify elements that provide resistance to lateral movement (1 mark)
urveying - Components - Undercut gauges and material of clasp to use for each undercut (6 mins)
● Mount cast and TRIPOD! (draw three lines with analysing rod and pencil)
○ Analysing rod: to analyse abutment teeth + soft tissue undercut (only)
○ Pencil rod: mark survey line of all abutment teeth and soft tissue undercut.
■ Do not overmark (in the common path of displacement)
● Determine whether the cast needs to be tilted i.e. when undercuts unfavourable - Change the path of insertion to highlight undercuts in this path. (mainly for soft tissue)
○ If cast needs to be tilted, re-tripod with red marker, then mark new survey line with red rod
● In the common path of displacement (path of insertion and removal if altered), find appropriate location for clasps with undercut gauges (normally buccal of upper molars and lingual of lower molars)
○ Mark the clasp positions with pencil!
○ 0.25mm → CoCr
○ 0.5mm → wrought Gold
○ 0.75 → wrought SS
Endo Restoration Options - Molar tooth - Explain to patient (6 mins)
● Gold standard: Cuspal coverage onlay
○ Gold, composite, porcelain, zirconia
■ Reduces risk of tooth fracture/catastrophic failure
■ Less microbial leakage/better seal
● Full coverage: MCC, GSC, all ceramic, all zirconia
○ If less tooth structure remains - in order to cover and protect
● Direct restoration: composite or amalgam
○ If only occlusal cavity present
○ Not as favourable: more leakage, more likely to fracture
○ Attempt to extend cavity just past the cusps to provide cuspal coverage.
● Core build up if necessary:
○ Gold standard: Composite core
○ Explain to pt the tooth has been hollowed out need to put filling material to fill up the space and retain the crown
○ Nayyar core - not favourable
○ Metal cast post not favourable
Identify types of crowns/bridges on casts - Cements used to bond each (6 mins)
GSC, MCC, Porcelain crown, Porcelain veneer, Adhesive Cantilever bridge
Pre + Post cementation checks
● When to use each cement:
○ Aquacem (GIC) → Metal post, MCC, Gold restorations, Zirconia restorations
○ Panavia (Anaerobic cure comp) → Adhesive bridge (RBB)
○ Nexus NX3 (Dual cure comp) → Fibre post, Composite/porcelain restorations, Veneers
● Pre-cementation checks
○ Check on the cast
■ Is the restoration as asked for
■ Rocking, M/D contact points, marginal integrity, aesthetics
■ Check contact points on adjacent teeth on cast to ensure not damaged
● Can be damaged when prepped tooth is sawn off the cast to invest
■ Occlusal interference on excursions
■ Natural teeth contacting (check with shimstock 8μm)
○ Remove crown from cast
■ Check if occlusion correct and still the same
■ Check crown thickness using calipers
○ Crown placed in patient with airway protection
■ Check all the above
■ Patient happy with appearance
● Post-cementation checks
○ Excess cement removed
○ No space around margins
○ Interproximal contact point exists and is clear
○ Occlusion checked with articulating paper (in excursion as well)
○ Restoration clensible
○ Confirm patient happy with aesthetics and feel
