Prosthetics Revision Clinical Steps Dr Charles Scola July 2004

Prosthetics RevisionProsthetics RevisionClinical StepsClinical Steps

Dr Charles Scola

July 2004

Prosthetics RevisionProsthetics Revision

Last two weeks we studied:Last two weeks we studied:Dentist / Patient expectationsDentist / Patient expectationsThe value of an old dentureThe value of an old dentureA written denture treatment planA written denture treatment planRVD = OVD + FSRVD = OVD + FSCopy Denture TechniqueCopy Denture TechniqueF/F Clinical techniquesF/F Clinical techniquesOverdenturesOverdentures

Meeting their needs & expectationsMeeting their needs & expectations

What sort of patient are they?What sort of patient are they?

Easy going or up-tightEasy going or up-tight Adaptable or preciseAdaptable or precise Accepting or demandingAccepting or demanding Cooperative or difficultCooperative or difficult

Asses their attitude & personality, Asses their attitude & personality, This is very important in denture toleranceThis is very important in denture tolerance NEVER promise what you cannot deliver !NEVER promise what you cannot deliver !

Your Denture Treatment PlanYour Denture Treatment Plan

This is your written prescription or recipeThis is your written prescription or recipe Without it you will get lost !Without it you will get lost !

It applies to new or old denture usersIt applies to new or old denture users Must be agreed with the patientMust be agreed with the patient Keeps you on the right trackKeeps you on the right track Is your record and defense, in case of later Is your record and defense, in case of later

problems or complaintsproblems or complaints

At every stage of treatmentAt every stage of treatment

Check your treatment planCheck your treatment plan Remind your patient of the planRemind your patient of the plan Explain what you are doing todayExplain what you are doing today Measure RVD & OVDMeasure RVD & OVD Look at the old dentures & compareLook at the old dentures & compare Observe the patient as they talk & smileObserve the patient as they talk & smile Remind the patient of the limitationsRemind the patient of the limitations

Vertical DimensionVertical Dimension

RVD is RVD is alwaysalways > OVD > OVD RVD should remain constantRVD should remain constant

whether dentures are worn or notwhether dentures are worn or notWhatever treatment you doWhatever treatment you do

OVD may be changed by OVD may be changed by youyou

All patients need FS, 2 – 5mmAll patients need FS, 2 – 5mm


RVD Freeway space


0VD


Today we are going to Today we are going to consider:consider:

Partial Denture planning & Partial Denture planning & designdesign

The clinical stages of partial The clinical stages of partial denture constructiondenture construction

Please read Dr Ulpee Darbar’s notes, these are very good !

Partial dentures often Partial dentures often grow up into full dentures- why ?grow up into full dentures- why ?

Partial dentures often grow up into Partial dentures often grow up into full dentures- why ?full dentures- why ?

Plaque Caries, perio disease

Trauma Abrasion, forced gingival recession, tissue

hyperplasia

Excessive forces Worsens perio disease, bone loss, mobility

Partial dentures – yes or no ?Partial dentures – yes or no ? So before we rush to make a partial So before we rush to make a partial

denture, ask yourself:denture, ask yourself: Will it do more harm than goodWill it do more harm than good Are there ‘safer’ alternativesAre there ‘safer’ alternatives Have you explained all the ‘pros and Have you explained all the ‘pros and

cons’ to your patient cons’ to your patient Partial dentures need plenty of Partial dentures need plenty of

maintenance, by you and the patientmaintenance, by you and the patient

Partial Dentures - BenefitsPartial Dentures - Benefits

AppearanceAppearance Face, lips, smile, sexyFace, lips, smile, sexy

FunctionFunction Chewing, biting, gripping, tearing, kissingChewing, biting, gripping, tearing, kissing

? Helps remaining teeth? Helps remaining teeth Spreads load, prevents tilting, over-eruption Spreads load, prevents tilting, over-eruption

? Prepares pt for full dentures ? Prepares pt for full dentures (Is this rather defeatist)(Is this rather defeatist)

Partial Dentures - designPartial Dentures - design

Must minimize plaque build up and allow pt to Must minimize plaque build up and allow pt to maintain good oral hygienemaintain good oral hygiene

Needs to avoid soft tissue traumaNeeds to avoid soft tissue trauma Should support and stabilize the remaining teeth Should support and stabilize the remaining teeth

without producing excessive occlusal or tipping without producing excessive occlusal or tipping forcesforces

Avoid your partial denture becoming:Avoid your partial denture becoming:1.1. a ‘gum stripper’ a ‘gum stripper’ 2.2. an orthodontic appliance !an orthodontic appliance !

Partial Dentures - designPartial Dentures - design RetentionRetention

Stops the denture falling outStops the denture falling out Suction, friction, muscular, mechanical (clasps etc)Suction, friction, muscular, mechanical (clasps etc)

Resistance or SupportResistance or Support Stops the denture being pushed in (gum stripper)Stops the denture being pushed in (gum stripper) Tissue or tooth borne ?Tissue or tooth borne ?

ConnectorsConnectors Joins the teeth, aids resistance & retentionJoins the teeth, aids resistance & retention Make it as patient-friendly as possibleMake it as patient-friendly as possible

Refer Dr Ulpee’s notes on clasps/ rest seats

Resistance or SupportResistance or Support

Stops the denture being pushed inStops the denture being pushed in A major cause of trauma to tissues !A major cause of trauma to tissues !

Tissue or tooth borne - Which is better?Tissue or tooth borne - Which is better? Teeth are made to take occlusal loadTeeth are made to take occlusal load Soft tissues are not !Soft tissues are not !

The effects of ‘sinking’ are:The effects of ‘sinking’ are: Trauma to gingivae and forced recessionTrauma to gingivae and forced recession Damage to mucosa by flanges and connectorsDamage to mucosa by flanges and connectors Denture teeth start to look too shortDenture teeth start to look too short Natural teeth may be tilted, intruded or loosenedNatural teeth may be tilted, intruded or loosened

Providing Resistance or SupportProviding Resistance or Support Bring the acrylic up over the cingulum of Bring the acrylic up over the cingulum of

anterior teeth,...if the bite allows it !anterior teeth,...if the bite allows it !

✖✔

Providing Resistance or SupportProviding Resistance or Support Bring the acrylic up over the bulbosity Bring the acrylic up over the bulbosity

of molars, ....if the bite allows it !of molars, ....if the bite allows it !

✔ ✖

Providing Resistance or SupportProviding Resistance or Support

You may need to cut a rest seat


Provide metal occlusal restsProvide metal occlusal rests With premolars & molars you cannot easily With premolars & molars you cannot easily

bring the acrylic over the occlusal bring the acrylic over the occlusal surface, ..but you can fit a metal occlusal surface, ..but you can fit a metal occlusal restrest

Your denture will ‘hang’ off the teeth


Occlusal rests;Occlusal rests; Make the denture ‘tooth borne’Make the denture ‘tooth borne’ Should be used wherever possibleShould be used wherever possible Are used on ‘strong’ teethAre used on ‘strong’ teeth Need to be positioned carefullyNeed to be positioned carefully Can be formed from stiff wire and inserted Can be formed from stiff wire and inserted

into the arylicinto the arylic


You may need to cut a rest seat


You may need to cut a channel for a clasp

This will also provide support

ConnectorsConnectors

Do not ‘pinch’ the gingivaeDo not ‘pinch’ the gingivae Keep 4mm awayKeep 4mm away

Do not cause food trapsDo not cause food traps Cross the gingival margins mid-tooth onlyCross the gingival margins mid-tooth only Keep the design simpleKeep the design simple Avoid cutting across rugae in palateAvoid cutting across rugae in palate

Follow them insteadFollow them instead Follow anatomical lines if possibleFollow anatomical lines if possible

Partial Dentures - planningPartial Dentures - planning As soon as you have your study models, and As soon as you have your study models, and

BEFORE you take your 2’ impressions:BEFORE you take your 2’ impressions:

Plan your design, considering all the pros & cons, Plan your design, considering all the pros & cons, and your patient’s wishesand your patient’s wishes

You may need to consider:You may need to consider: More extractionsMore extractions

Hopeless prognosis, deep undercutsHopeless prognosis, deep undercuts ConservationConservation

Reshape opposing teeth, Reshape opposing teeth, Cut rest seats, channels for clasps, guide planes Cut rest seats, channels for clasps, guide planes Remove undercuts, create undercutsRemove undercuts, create undercuts

Guide Planes & Occlusal RestsGuide Planes & Occlusal Rests

Partial DenturesPartial DenturesLets try to design a fewLets try to design a few

Follow these principles:Follow these principles:

Which teeth are to be replacedWhich teeth are to be replaced Design Design connectorsconnectors and outlines and outlines

Avoid palatine papilla if possibleAvoid palatine papilla if possible Consider undercuts & path of insertionConsider undercuts & path of insertion

Provide resistance & retentionProvide resistance & retention Do any teeth need cutting, reshaping, or exoDo any teeth need cutting, reshaping, or exo Draw on your model & write your treatment planDraw on your model & write your treatment plan

Partial Dentures, 2’ ImpsPartial Dentures, 2’ Imps

Check your treatment planCheck your treatment plan Cut or reshape any teeth as needed, ?undercutsCut or reshape any teeth as needed, ?undercuts Check your special tray covers all areas that are Check your special tray covers all areas that are

crucial to your designcrucial to your design Take good alginate impressions, use your fingerTake good alginate impressions, use your finger Take your shadeTake your shade Check the occlusion, ? take a wax bite, you may Check the occlusion, ? take a wax bite, you may

not need to take MMR using bite blocksnot need to take MMR using bite blocks

Partial Dentures, MMRPartial Dentures, MMR

Will only be needed if:Will only be needed if:

Many teeth are missingMany teeth are missing There are free end saddlesThere are free end saddles There is no tooth to tooth contactThere is no tooth to tooth contact The existing occlusion needs to be raised, The existing occlusion needs to be raised,

or changed in some way (rare)or changed in some way (rare)

Partial Dentures, MMRPartial Dentures, MMR

Check fit and stability of wax blocksCheck fit and stability of wax blocks Trim occlusal levels to follow natural teethTrim occlusal levels to follow natural teeth If there is tooth to tooth contact, use this If there is tooth to tooth contact, use this

occlusion unless there is a specific reason occlusion unless there is a specific reason to change itto change it

Record bite blocks in centric occlusionRecord bite blocks in centric occlusion Mark centre linesMark centre lines

Partial Dentures, Try - InPartial Dentures, Try - In

Confirm smile lines and levelsConfirm smile lines and levels Agree aesthetics with the patientAgree aesthetics with the patient Similar steps to F/F try in:Similar steps to F/F try in: Assess accuracy of the occlusionAssess accuracy of the occlusion

But also:But also: Check resistance – Check resistance – is occlusion affectedis occlusion affected Check retention - Check retention - will clasps showwill clasps show Hygiene – Hygiene – are there food trapsare there food traps Soft Tissues – Soft Tissues – any risk of traumaany risk of trauma

Partial Dentures, FittingPartial Dentures, Fitting

Try them in gently, never force themTry them in gently, never force them Adjust carefully to ensure a snug fitAdjust carefully to ensure a snug fit Check occlusion, ? Tooth to tooth contactCheck occlusion, ? Tooth to tooth contact Check aesthetics, ? Objectives achievedCheck aesthetics, ? Objectives achieved Ensure comfort, no traumaEnsure comfort, no trauma Teach patient how to fit and remove themTeach patient how to fit and remove them

Don’t use clasps as ‘handles’Don’t use clasps as ‘handles’ Give full cleaning & maintenance instructionsGive full cleaning & maintenance instructions

Don’t wear them 24 / 7, give your mouth a restDon’t wear them 24 / 7, give your mouth a rest


Today we have reviewed: Today we have reviewed:

Partial Denture planning & Partial Denture planning & designdesign

The clinical stages of partial The clinical stages of partial denture construction denture construction

Documents

Prosthetics Revision Clinical Steps Dr Charles Scola July 2004