REM PROS REVISION LEC CARDS Flashcards
Why make the mouth healthy before starting dentures? (3)
Dentures more comfortable if tissues healthy
Dentures can make dental disease worse
Dentures last longer (tx e.g. XLA can change the fit surface of the denture
What oral structures are we making healthier (pre-denture)? (3)
Oral mucosa
Teeth
Periodontal tissues
What is denture stomatitis? List KEY facts to do w/ denture hygiene? (6) (Pre-tx; oral mucosa)
Definition: ‘Denture sore mouth’ localised non-communicable oral candida infection affecting the palate + gingiva (acute or chronic)
Caused by candida albicans
Key causes 1) poor denture cleaning 2) keeping denture in overnight
Assoc w/ angular chelitis
Tx: nystatin oral suspension OR miconazole gel
(Consider immunosuppression, pt risk suspectibility/ referral tests)
ORAL ULCERS - non-denture + denture related? (2) (Pre-tx; oral mucosa)
Mouth ulcers COMMON + should resolve in 2-3w (arrange review + urgent referral to OM for persistant ulcers of unknown cause)
Denture related = TRAUMATIC ULCER from poor fitting denture (remove cause e.g. over-extension of denture)
What is BRONJ? + how do we manage? (Pre-tx; oral mucosa)
Bisphosphonate related osteonecrosis of the jaw
Management = Referral
How do identify/manage denture if causing trauma / trauma rx ulcers? (3) (Pre-tx; oral mucosa)
- Assess if denture border too long for sulcus
- Identify area causing trauma w/ pressure paste + trim back w/ acrylic bur
- Temporary soft lining may help
How do you use pressure paste to identify area of trauma? (2) (Pre-tx; oral mucosa)
Apply pressure paste to edge of denture
Trim pink acrylic showing through w/ paste still there
How do you use soft linings to ease area of trauma? (3) (Pre-tx; oral mucosa)
Mix + apply to fit surface
Place in mouth to mould to shape
Trim excess (lasts weeks/months + allows tissues to recover)
What is denture granuloma? Management? (4) (Pre-tx; oral mucosa)
Definition = chronic inflammation (of upper arch that is denture rx
Management:
Remove cause (usually denture rx)
Review to see if reduced in size (several months)
Surgery (last resort)
Why manage caries + perio disease before starting dentures?(2) ; state tx (3) (Pre-tx; oral mucosa)
Dentures attract plaque (any plaque rx diseases made worse)
So, **dentures fit the teeth in their final form **
THEREFORE
Complete all direct + indirect restorations before
Plaque score < 20%
XLA of poor prognosis + allow healing (6-8w)
Key considerations re tooth-wear before making dentures? (3) (Pre-tx; oral mucosa)
Decide what to do about worn teeth before making dentures (tx plan for worn teeth)
Restore before making dentures usually (eg. Composite or indirect restorations)
Tx will result in increased OVD (so, new OVD established before denture = better denture success)
Reasons for using articulated casts? (6) (;Articulated cast)
Easier to view incisal relationship from palatal aspect
To observe occlusion for denture design purposes (positioning of rests and assess interocclusal space)
Examine static and/or dynamic occlusion
Plan changes in OVD (wear cases)
Make diagnostic changes prior to irreversible treatment (composite build-ups/indirect restorations)
Use as a visual aid when discussing treatment options with patient
What material is used for primary impressions?
Alginate
How/tips on selecting stock tray? (5)
Use imprint of teeth on a sheet of wax for tray selection
Be able to insert tray into the mouth w/o discomfort + comfortable when seated
Tray should touch occlusal surfaces on both sides to indicate it is seated
Tray covers all the teeth + soft tissues that you wish to record (or can be modified easily if under-extended e.g. using pink wax)
Be able to move tray sideways showing enough space for alginate between tray & tissues
How to get accurate reading of sulcus area?(8) -primary + secondary imps
1.Check tray extends to full height of the sulcus (2mm gap between tray + sulcus)
- Add double layer of wax to extend borders if tray too short in sulcus area
- Ensure frenal attachments not squashed (cut grooves in wax if too long)
- Pre-load some sulcus areas with alginate to avoid trapping air (esp labially)
- Ensure sufficient impression material where you need it (enough in the stock tray?)
- Seat tray correctly so that impression material can flow over tray borders correctly
- Border moulding (by pt +/ operator) whilst impression material setting
- Ensure detachable handle does not interfere with lip movement (is it fitted correctly?)
How do you manage gagging pt during impressions? (4)
Correct tray size - ensure impression tray (+ extensions) not too large
Impression material – right amount of impression material (not XS)
Impression material – fast-setting where possible
Distract patient during impression (deep, steady breathing, wiggle toes etc)
List 4 instructions for correct disinfection + storage of impressions (Alginate or silicone) (2)
Rinse – with water under the tap to remove debris
Rinse – low in sink/away from you to prevent splash back
Disinfect – soak for required time (10 mins proform)
Rinse again - to remove chemicals
Alginates keep moist – wrap completely in damp gauze/tissue. Store in sealed bag to prevent drying out
Elastomeric impression materials (silicones) store dry and protect with paper or bubble wrap
List 6 ways to reduce errors when casting? (6)
Cast ASAP + within 24 hrs (alginate ASAP, silicone not as urgent)
Ensure no debris/excess liquid inside impression when casting
Remove excess alginate from impressions borders where it might distort impression when sitting on the bench
Ensure plaster or stone mixed correctly + of correct consistency (not too thick or watery)
Run a thin layer of mix over teeth area first to avoid air getting trapped in teeth
Use vibrating table to eliminate air bubbles in mix
Leave stone in impression to set properly first before turning over to base the cast
Remove impression once cast is based (this prevents interaction of materials + surface damage)
What is meant by jaw relation? (2) (;jaw reg stage)
3D spatial relationship between the upper + lower jaws (or teeth)
Both a VERTICAL + HORIZONTAL component
What is meant by horizontal jaw relationship? (3) State rationale (1) (;jaw reg stage)
- Two positions are intercuspal position (ICP) and retruded contact position (RCP) (aka centric relation)
- Use ICP – when there are sufficient opposing pairs of posterior teeth to record a reproducible ICP
- Use RCP/centric relation – if insufficient natural teeth to record ICP, or if the patient’s OVD is to be increased (typically wear cases)
Rationale = choose an occlusal rx that is reproducible + so kept the same throughout all stages of making a denture
What horizontal rx do we use in wear cases and why?
even if someone has stable ICP, in wear cases you are increasing OVD so you are loosing stable ICP
therefore we use RCP
Give the full definition of RCP
Retruded Contact Point
A bilateral, unstrained position of the mandible in which the condylar disc assembly(CDA) is in the most anterior superior position (ASP) within the glenoid fossa. (GF)
In this position, the initial 20mm of incisal opening is a pure ”hinge” movement around the hinge axis.
If natural teeth are present, RCP is the point of initial tooth contact as the jaw closes around the hinge axis.
What is the ideal occlusion for partial dentures?
For partial dentures use natural teeth as a guide to denture position WHERE POSSIBLE i.e. ICP where it is reproducible
Where the vertical dimension is determined by natural teeth but there are NOT enough inter-cuspating posteriors to determine horizontal jaw position RCP is used.
When do we need occlusal rims? (2)
To support casts when articulating
Hand articulation not possible without rim (or interocclusal record alone not sufficient)
(regardless of occlusal rims being needed we always need the intraocclusal record which relates the horizontal position between upper + lower jaws)
What ways can you articulate a study cast when using ICP? (2)
Hand articulated casts
OR
Facebow to articulate
Ways/process of articulating a study cast when using RCP?
(These casts cannot be hand articulated)
Therefore to mount on an articular, you need:
- occlusal rims
- interocclusal record
- facebow
What is the purpose of occlusal rims?
provide a shape to whoever is making denture on where to set teeth + to indicate where the lip support is and incisal edges etc
Why use a facebow? (4)
- is used to record the 3D rx between the upper occlusal plane and the terminal hinge axis in the patient
The facebow then transfers this relationship onto the articulator
This enables the articulator to simulate the patient’s jaw movements better
If the articulator simulates the patient better, then any restorations made on the articulator (eg. dentures) are more likely to conform to the patient’s occlusion + be more acceptable to the patient
What is the purpose of a face bow? (3)
To record the relationship between upper occlusal plane + terminal hinge axis in the patient
Then use facebow to transfer this onto the articulator
Use facebow to articulate upper cast
State 3 considerations for jaw reg of edent pt
No guide of where pt’s previous teeth were, so need occusal rims + inter-occlusal record for Jaw relationship
Jaw relationship recorded in RCP
Occlusal rims for e.dent pt can be made in wax, self-cure acrylic or heat- cure acrylic
(Note for partially dentate pt heat-cure acrylic not used)
How do we measure freeway space for an edentulous patient? (5)
Ideally 2 - 4 mm for an edentulous patient
Use a Willis gauge as a measuring tool
Measure occlusal vertical dimension (OVD) w/ both dentures in
Measure rest vertical dimension (RVD) w/ at least one denture out
Calculate RVD- OVD = FWS
What could happen if there is not enough freeway space (FWS)? (4) (;edent pt)
- Might get soreness under one/both dentures (trauma may be visible on soft tissues)
- Aching jaw muscles (OVD too excessive or not enough freeway space and no room to move)
- Patient wants to leave dentures out because uncomfortable to wear. Patient may say “dentures feel too big or they feel like a mouth full”
- Appearance may not be unacceptable - showing too much tooth/ or patient’s lips become incompetent because mandible & maxilla are too far apart
What could happen if there is too much freeway space (FWS)? (6) (;edent pt)
Might see deep creases at the corners of the patient’s mouth (both sides usually)
Might see infection/redness/soreness at corners of the mouth (possibly angular cheilitis)
May also have denture stomatitis on palate (possibly same time as angular cheilitis, because both can be candida related)
Patient may complain of poor appearance (i.e.. poor lip support or reduced denture tooth height)
Patient may have jaw/muscle ache because they are over- closed (OVD too small)
Patient may show very worn denture teeth/and also have difficulty chewing food if occlusal surfaces flat or misshapen
Positioning artificial upper anterior teeth in denture patients? (6)
Match denture teeth midline to midline of face (nose and between the eyes when smiling or incisive papilla)
**Incisal edges near (or 1-2 mm below) lower border of upper lip at rest. **
** Lip support favourable** (approx. 90-degree angle between lower border of nose and upper lip profile looking from the side)
Match long axes of upper denture teeth with patient’s sagittal plane/midline (symmetry and converging slightly inwards + downwards ideal)
**Look at denture gingival margins + lower border of upper lip when smiling **(to see how much pink wax/acrylic is showing)
Compare denture tooth position against natural teeth (eg. anterior overjet & overbite, or arch shape)
Reasons for surveying caste? (2) RPD
Clasp planning - to identify suitable undercuts on natural teeth for clasps
Blocking out - to identify unwanted/undesirable undercuts on teeth
Do you need to articulate study casts? (1) RPD
Yes - may need to take a jaw registration to articulate primary casts to help design denture
(FOR CO-CR WE NEED TO)
Define PATH OF INSERTION (RPD)
The path of insertion is the path followed by the denture from its initial contact with the teeth until it is fully seated.
Define GUIDE PLANES (RPD)
Guide planes are two or more parallel (axial) tooth surfaces on abutment teeth which are used to restrict the path of insertion of a partial cobalt chrome denture.
Define NATURAL GUIDE PLANE (RPD)
A natural guide plane is one that already exists on a proximal tooth surface or a restoration.
Define ARTIFICIAL GUIDE PLANE (RPD)
An artificial guide plane is one that the dentist prepares on a proximal tooth surface using a bur, or one that is incorporated into an indirect restoration (usually a crown).
(Original curved contours of tooth modified to flat surfaces using parallel-sided diamond bur + fast handpiece)
What type of denture are guide planes used for? (RPD)
They are only used for cobalt chrome partial dentures (not acrylic dentures).
All guide planes should be drawn on a partial cobalt chrome denture design.
Sometimes it is not possible to have a guideplane… what is the consequence of this? RPD
Sometimes it is not possible to have guide planes, and this just means that the path of insertion is less controlled.
Advantages of guide planes for Co-cr partial dentures?(6) RPD
Control path of insertion of a denture
Facilitate easy insertion + removal of dentures (denture has a particular direction it moves in)
Contribute to overall retention of the denture (undercuts more predictable/precise)
Minimise wedging stresses on abutment teeth (forces that act laterally on natural teeth)
Reduce amount of ‘blockout’ or ‘deadspace’ (space between denture + natural teeth where there are tooth undercuts)
Aid denture stability (prevents movement during function because clasps more efficient)
State two reasons why tooth support is important? (2);CoCr RPD
to spread occlusal forces onto natural teeth (minimises trauma to soft tissues under the denture)
Rests on teeth are designed to direct the occlusal load down the long axis of the natural tooth (rather than from the side which might tip the tooth) (Co-Cr)
State two functions of occlusal rests? RPD
Provide tooth support to spread occlusal forces onto natural teeth (which minimises trauma to soft tissues under the denture)
Rests on teeth are designed to direct the occlusal load down the long axis of the natural tooth (rather than from the side which might tip the tooth)
Tooth preps for partial denture? -type of denture (1) and 2 types of tooth prep (2) ;RPD/Co-cr
These are for cobalt chrome partial dentures only!!!
… and include
1. guide planes
2. rest seats
What are 3 types of rest seats? RPD; Co-cr
Occlusal
Cingulum
Incisal
Rationale for rest seat preparation? (2) RPD; Co-Cr
To provide space between the occlusal surfaces of upper and lower teeth to allow a rest of adequate thickness to be used
To provide **more suitably inclined bearing surfaces than those existing on unprepared teeth ** (ie. greater horizontal inclination)
State the 4 classes of the Kennedy Classification? RPD Co-Cr
- Class I (bilateral free ended partially edentulous)
- Class II (unilateral free ended partially edentulous)
- Class III (unilateral bounded partially edentulous)
- Class IV (bilateral bounded anterior partially edentulous)
State the component parts of a partial denture? RPD; Co-Cr (9)
1 Saddle
2 Denture teeth (saddle)
3 Guide plane
4 Rest seat – support
5 Retention
6 Reciprocation
7 Connector
8 Acrylic
9 (Any abutment teeth)
Define an occlusally approaching clasp? (Co-cr)
Occlusally approaching. This is when retentive arm approaches the tooth undercut from the occlusal direction. The terminal third of the clasp arm is below the survey line. But sometime more conspicuous.
(most clasps approaching from occlusal and then undercut)
What are the 4 type of occlusal clasps?(4) ;Co-cr
1 Occlusally approaching clasp
2 Reverse C clasp
3 Ring Clasp
4 Double arm clasp
Define Gingivally Approaching Clasp? (;RPD, Co-Cr)
Gingivally approaching clasp = the retentive clasp arm approaches the tooth undercut from the gingival direction.
Such clasps produce a trip action when being forced out of the undercut. This action = MOST effective ways of retaining the denture
State the 4 different types of gingivally approaching clasps? (4)
Y clasp
T clasp
Half T
Ball ended
State the different types of upper major connectors? (5) ;CoCr
Palatal strap
Palatal plate
Palatal horseshoe
Anteroposterior bar
Combination of chrome + acrylic
List the 6 different types of lower major connectors?(6) ;Co-Cr
Lingual bar
Sublingual bar
Lingual plate
Split lingual plate
Dental bar
Buccal/labial bar
Benefits of Co-Cr partial dentures? (6)
Stronger
Less bulky
Hygienic design possible with less ocverage of sof tissues
Provides tooth support (so less trauma to soft tissues
Easier to keep cleaner
(less easy to modify than acrylic though)
List 7 advantages of CoCr partials compared to acrylic partials? (7)
Tooth support possible so less trauma to soft tissues likely
Clasps tend to be more effective if guide planes used (and if designed correctly)
Better support + direct retention makes the denture more stable (moves around less during function)
Less bulky so better tolerated by patient
Hygienic designs possible so less gingival coverage (protects periodontal health)
Less plaque retention around teeth (lower caries risk)
Metal stronger so major connector can be thinner + tolerated better
What are the steps for making an immediate ACRYLIC denture (partial) to replace extracted teeth? (3)
- Start making a partial acrylic denture around the teeth to be extracted
2. Then add extra teeth to the denture before being finished
- Extract teeth and fit immediate denture at the same visit
Purpose of secondary/ master impressions?(2)
Facilitate more accurate impressions for making dentures
Special tray helps impression accuracy (because it covers all the areas needed and the impression material is fairly even in thickness + not too thick which reduces distortion).
Key facts about Co-Cr framework try-in stage? (2) RPD
(Make and fit cobalt chrome framework)
Need to do this before adding denture teeth
Usually, fit framework first + then add wax rims to do jaw registration rather than make separate rims
What to do at tooth try-in in pink wax? (2) ;try-in
Choose shape and shade of denture teeth at the previous visit. Use previous dentures/photos as a guide.
Check all aspects of dentures are correct shape/position and make changes as necessary before next stage
What can go wrong during denture flasking?(7) ;flask pack and finish stage
Contraction porosity - not enough dough in flask/ or flask not closed properly leaving spaces
Gaseous porosity - flask heated up too quickly in early stages of denture processing. Monomer turns to gas making bubbles
Granular porosity – dough mixture too dry initially/ or is left uncovered before packing into flask (monomer evaporates)
**Uncured chemicals ** – usually uncured monomer which can be irritant/toxic (unsafe so must remake denture)
Structure may be weaker if not cured properly, or there are cracks or porosity (remake denture)
Appearance may change – decide with patient if unsatisfactory/ or needs remake or a modification
**Acrylic can distort ** + denture may not fit well (even after adjusting).
What 3 things do you check at denture fit? (3) ; denture fit
Check fit surface(s) + adjust (pressure indicating paste, if needed)
Check and adjust occlusal surface(s) with articulating paper
Give denture instructions (ulcers, cleaning, review appts)
What instructions would you give to pt after fitting the denture? (wearing the denture) (3) ;denture fit
Only wear during the day (not at night) to avoid denture stomatitis.
Don’t wear during the day if painful/cause ulcers
So,just wear on the day of review appointment to avoid unnecessary pain and remind patient of sore area(s)
What instructions would you give to pt after fitting the denture? (CLEANING the denture) (3) ;denture fit
Scrub all surfaces gently (so does not scratch) using soft denture brush and warm soapy water (no harmful chemicals)
Clean over a sink/bowl of water to avoid denture fracture if dropped on hard surface
Clean twice a day and when leaving out at night (e.g. after food to remove debris that might lead to denture plaque).
List 7 mouth care for instructions for denture wearers? (7)
Brush natural teeth properly, morning + before bedtime
Make sure can remove dentures easily
Brush dentures twice daily with soft brush + soap/denture paste
Brush dentures over a sink of water in case drop it
Don’t wear dentures at night to keep tissues healthy
If they experience any soreness/pain associated with the denture, leave denture out and make an appointment to see the dentist to check it
Advise annual check-ups for dentures as well as natural teeth
When do you do a denture review? (state both appointments)(2) ;denture review
Review patient after short time (1-2weeks if poss) + then again as necessary.
We often recommend a final review after a few months just to check all is fine before discharging patient
How would you adjust denture acrylic at fit/review visits? (4)
Use pressure paste/spray on denture fit surfaces (especially buccally near the tuberosities)
Seat denture and apply even pressure both sides occlusally
Remove approx. 1⁄2 mm thickness of acrylic in the pink acrylic areas (showing through the paste) and blend this in with the rest of the fit surface if possible. (This relieves high spots on the denture fit surface so that the rest of the fit surface adapts to the underlying tissues better, thus improving retention).
Do the same for the denture borders if they are too long (overextended). This should prevent trauma to the sulcus tissues.
If the pt has no complaints w/ their denture during the fit/review – what 3 things do you still check? ;denture review/problems
Check the occlusion again in case needs further adjustment (articulating paper GHM)
Remove the denture(s) and check the health of the soft tissues underneath
Check oral and denture hygiene
State 5 things that influence how well the pt might adapt to the denture? (even if no issues w/ the denture) (5) ;denture problems
Previous denture experience (poor)
Degree of change (in shape) between old and new
Quality of dentures
Patient factors (age, oral and general health)
Patient expectations (patient complaint)
State 3 reasons why there might be pain under dentures? (3) ;denture problems
Denture fit surface is the wrong shape (such as impression fault, casting fault, denture processing error at the end)
Denture fit surface is the correct shape, but the tissues underneath are more sensitive (such as compression of mental nerve, or buried root just under mucosa, or irregular bone surface causing pain or when mucosa squashed against it under a denture)
The occlusal load transmitted through a denture is more than the mucosa can tolerate (occlusal high spot on a denture, or denture OVD too high, or denture support lacking)
How do you detect sensitive tissues under dentures? () ;denture problems
Dry mucosa
Palpate soft tissues
Apply pressure paste on tissue
Place denture in the mouth
Trim the denture where the paste is
How to detect excessive occlusal load transmitted through denture onto mucosa causing pain? (4) ;denture problems
Examine site of pain to exclude non-denture related pathology (typical presentation of denture trauma is redness/soreness/ulcer on mucosa).
Examine natural occlusion without dentures to establish how the patient should occlude when the dentures are in the mouth (use articulating paper or shimstock.
Put upper denture in mouth and use articulating paper or shimstock to examine if denture teeth high.
Use articulating paper to identify where the high spots are on the denture teeth. Then remove them with an acrylic bur until the natural teeth come back into contact
(adjust high tooth spot first and see if this resolves
if it does not then do prophy paste step and adjust the fit surface as
you would otherwise)
List 5 reasons dentures can be loose? (5) ;denture problems
Lack of clasps on teeth (or they do not work properly).
**Denture fit surface incorrect shape so denture wobbles. **
Uneven occlusal contact on dentures can cause them to tip or move during function.
**Polished surface(s) too bulky and facial muscles or tongue displaces denture **
In complete dentures, **a lack of suction effect (known as ‘peripheral seal’) can cause looseness. **
This is often because the denture border is not well adapted in the sulcus areas or there is no effective post dam at the back of an upper complete denture.
What happens when polished surface are the wrong shape? (1) ;denture problems
Soft tissues displace the denture
(lingual undercuts + the tongue pushes off the denture during function)
What is the likely cause of pain on lateral excursion? (1) ;denture problems
The coronoid process is against the side of the denture (need to trim denture to adjust)
What can cheek biting be a result of ? (1) ;denture problems
No buccal overjet
(need to create buccal overjet to prevent cheek biting)
What are possible reasons for pt gagging with denture in? (4) ;denture problems
Upper denture too far back (onto soft palate)
Upper denture loose
Excessive OVD
Lack of tongue space
Factors to consider for a broken denture? (5) ; denture problems
What is the cause (is it uneven occlusion + flexing of denture, or thin acrylic, or was the denture dopped)?
**Is there a previous repair? **
Do the pieces fit together properly out of the mouth, or do you need something to temporarily hold the pieces together before sending to the lab for a repair?
**Do you need an opposing cast? **Take an alginate impression.
**Is recurrence likely? **If yes, then consider a new denture.
List 6 causes of mid-line fractures? (6) more common in upper denture ;denture problems
Open flanged denture
Deep frenal notch
Midline diastema
Alveolar resorption under denture (denture flexes in midline)
Unfavourable occlusal forces (tooth wear)
Thin acrylic (increases fracture chances)
What is the difference between reline + rebase? (2) ;denture problems
Reline - modifies the denture fit surface only (new acrylic resin)
Rebase - modifies the polished surface too
What is the impression technique for relines? (2)
Remove undercuts
Use light-bodied, flexible impression material (not Zinc Oxide paste)
What are 3 problems with relining or rebasing? (3)
Increase in OVD (use thin layer of impression material)
Occlusal errors (can use “closed mouth technique” but beware excess material)
Damage during laboratory processing (warn patient might not be able to wear denture)
List 5 steps for adding a tooth to a denture for a planned extraction (immediate addition)? (5) PROCESS
Choose correct size of tray
Add wax where tooth is being added to record full depth of sulcus
Take over impression
Take lower impression if occlusion important
Write labcard
