Prosthetics Revision Clinical Steps

1. Prosthetics RevisionClinical Steps Dr Charles Scola July 2004

2. Prosthetics Revision Last two weeks we studied: Dentist / Patient expectations The value of an old denture A written denture treatment plan RVD = OVD + FS Copy Denture Technique F/F Clinical techniques Overdentures

3. Meeting their needs & expectations • What sort of patient are they? • Easy going or up-tight • Adaptable or precise • Accepting or demanding • Cooperative or difficult • Asses their attitude & personality, • This is very important in denture tolerance • NEVER promise what you cannot deliver !

4. Your Denture Treatment Plan • This is your written prescription or recipe • Without it you will get lost ! • It applies to new or old denture users • Must be agreed with the patient • Keeps you on the right track • Is your record and defense, in case of later problems or complaints

5. At every stage of treatment • Check your treatment plan • Remind your patient of the plan • Explain what you are doing today • Measure RVD & OVD • Look at the old dentures & compare • Observe the patient as they talk & smile • Remind the patient of the limitations

6. Vertical Dimension • RVD is always > OVD • RVD should remain constant • whether dentures are worn or not • Whatever treatment you do • OVD may be changed by you • All patients need FS, 2 – 5mm

7. Vertical Dimension RVD Freeway space

8. Vertical Dimension 0VD

9. Prosthetics Revision • Today we are going to consider: • Partial Denture planning & design • The clinical stages of partial denture construction

10. Partial Dentures Please read Dr Ulpee Darbar’s notes, these are very good !

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

12. Partial dentures often grow up into full dentures- why ? • Plaque • Caries, perio disease • Trauma • Abrasion, forced gingival recession, tissue hyperplasia • Excessive forces • Worsens perio disease, bone loss, mobility

13. Partial dentures – yes or no ? • So before we rush to make a partial denture, ask yourself: • Will it do more harm than good • Are there ‘safer’ alternatives • Have you explained all the ‘pros and cons’ to your patient • Partial dentures need plenty of maintenance, by you and the patient

14. Partial Dentures - Benefits • Appearance • Face, lips, smile, sexy • Function • Chewing, biting, gripping, tearing, kissing • ? Helps remaining teeth • Spreads load, prevents tilting, over-eruption • ? Prepares pt for full dentures • (Is this rather defeatist)

15. Partial Dentures - design • Must minimize plaque build up and allow pt to maintain good oral hygiene • Needs to avoid soft tissue trauma • Should support and stabilize the remaining teeth without producing excessive occlusal or tipping forces • Avoid your partial denture becoming: • a ‘gum stripper’ • an orthodontic appliance !

16. Partial Dentures - design • Retention • Stops the denture falling out • Suction, friction, muscular, mechanical (clasps etc) • Resistance or Support • Stops the denture being pushed in (gum stripper) • Tissue or tooth borne ? • Connectors • Joins the teeth, aids resistance & retention • Make it as patient-friendly as possible • Refer Dr Ulpee’s notes on clasps/ rest seats

17. Resistance or Support • Stops the denture being pushed in • A major cause of trauma to tissues ! • Tissue or tooth borne - Which is better? • Teeth are made to take occlusal load • Soft tissues are not ! • The effects of ‘sinking’ are: • Trauma to gingivae and forced recession • Damage to mucosa by flanges and connectors • Denture teeth start to look too short • Natural teeth may be tilted, intruded or loosened

18. Providing Resistance or Support • Bring the acrylic up over the cingulum of anterior teeth,...if the bite allows it ! ✔ ✖

19. Providing Resistance or Support • Bring the acrylic up over the bulbosity of molars, ....if the bite allows it ! ✔ ✖

20. Providing Resistance or Support You may need to cut a rest seat

21. Providing Resistance or Support • Provide metal occlusal rests • With premolars & molars you cannot easily bring the acrylic over the occlusal surface, ..but you can fit a metal occlusal rest Your denture will ‘hang’ off the teeth

22. Providing Resistance or Support • Occlusal rests; • Make the denture ‘tooth borne’ • Should be used wherever possible • Are used on ‘strong’ teeth • Need to be positioned carefully • Can be formed from stiff wire and inserted into the arylic

23. Providing Resistance or Support You may need to cut a rest seat

24. Providing Resistance or Support You may need to cut a channel for a clasp This will also provide support

25. Connectors • Do not ‘pinch’ the gingivae • Keep 4mm away • Do not cause food traps • Cross the gingival margins mid-tooth only • Keep the design simple • Avoid cutting across rugae in palate • Follow them instead • Follow anatomical lines if possible

26. Partial Dentures - planning • As soon as you have your study models, and BEFORE you take your 2’ impressions: • Plan your design, considering all the pros & cons, and your patient’s wishes • You may need to consider: • More extractions • Hopeless prognosis, deep undercuts • Conservation • Reshape opposing teeth, • Cut rest seats, channels for clasps, guide planes • Remove undercuts, create undercuts

27. Guide Planes & Occlusal Rests

28. Partial DenturesLets try to design a few • Follow these principles: • Which teeth are to be replaced • Design connectors and outlines • Avoid palatine papilla if possible • Consider undercuts & path of insertion • Provide resistance & retention • Do any teeth need cutting, reshaping, or exo • Draw on your model & write your treatment plan

29. Partial Dentures, 2’ Imps • Check your treatment plan • Cut or reshape any teeth as needed, ?undercuts • Check your special tray covers all areas that are crucial to your design • Take good alginate impressions, use your finger • Take your shade • Check the occlusion, ? take a wax bite, you may not need to take MMR using bite blocks

30. Partial Dentures, MMR • Will only be needed if: • Many teeth are missing • There are free end saddles • There is no tooth to tooth contact • The existing occlusion needs to be raised, or changed in some way (rare)

31. Partial Dentures, MMR • Check fit and stability of wax blocks • Trim occlusal levels to follow natural teeth • If there is tooth to tooth contact, use this occlusion unless there is a specific reason to change it • Record bite blocks in centric occlusion • Mark centre lines

32. Partial Dentures, Try - In • Confirm smile lines and levels • Agree aesthetics with the patient • Similar steps to F/F try in: • Assess accuracy of the occlusion • But also: • Check resistance – is occlusion affected • Check retention - will clasps show • Hygiene – are there food traps • Soft Tissues – any risk of trauma

33. Partial Dentures, Fitting • Try them in gently, never force them • Adjust carefully to ensure a snug fit • Check occlusion, ? Tooth to tooth contact • Check aesthetics, ? Objectives achieved • Ensure comfort, no trauma • Teach patient how to fit and remove them • Don’t use clasps as ‘handles’ • Give full cleaning & maintenance instructions • Don’t wear them 24 / 7, give your mouth a rest

34. Prosthetics Revision • Today we have reviewed: • Partial Denture planning & design • The clinical stages of partial denture construction

35. That's all for today thank you for listening!