Denture Placement

1
Denture Placement Occlusion Correction

• Rola M. Shadid, BDS, MSc

2
Causes of Denture Errors

• Clinical errors
• Technical errors
• Inherent deficiencies in the material itself

3
Evaluation Procedures

• Processing
• Polished surfaces
• Tissue fit and comfort
• Retention, stability and support
• Jaw relations
• Occlusion
• Esthetics
• Speech

4
Evaluation of Processing

• Inspect for processing errors, e.g. porosity
• Inspect for inadequate polishing
• Run your finger along the borders impression
  surface to check if sharp edges or acrylic
  spicules exist
• Examine frenal notches for sharp edges
• Examine for adhered plaster or stone fragments

5
Patient Education Preparation

• First oral feeling with fullness is normal will
  disappear over time
• Excessive salivation
• (compulsive spitting or rinsing should be
  avoided, instead swallowing encouraged to remove
  excess saliva)

6
Evaluation of Tissue Fit Comfort

• Pressure Indicating Paste (PIP)
• Every new denture must be checked with PIP to
  identify and determine if pressure areas exist to
  reduce them.

7
Evaluation of Tissue Fit Comfort

• Never adjust unless you can see exactly where to
  adjust
• Use indicator medium
• (PIP, indelible marker, etc)

8
Place Paste with Streaks
9
How to Read PIP?

• Streaks - no contact (N)
• No Paste - Impingement (I)
• Paste, no streaks - normal contact (C)

10
Evaluation of Tissue Fit Comfort

• Severe undercuts
• Cause abrasion and soreness in seating and
  removal
• Management
• Relieve with extreme caution with aid of PIP

11
Evaluation of Tissue Fit Comfort

• Overextended borders
• Denture appears to rise or has inadequate
  retention
• Management
• Identify the offending borders, mark with
  indelible marker inside the pt mouth and
  carefully reduce

12
Evaluation of Retention, Stability Support

• Test for retention
• Test for posterior palatal seal

13
Test for Rocking

• Apply alternating finger pressure on occlusal
  surfaces of R L sides
• Rocking around fulcrum point
• Midpalatal raphe is a common fulcrum point if
  inadequate relief has been provided

14
Evaluation of Occlusion

• Denture processing almost always causes changes
  in occlusion due to dimensional changes in resin
• These changes are usually manifested as increase
  in OVD

15
Causes of Occlusal Errors

• Errors in impressions
• Ill-fitting trial denture bases
• Inaccurate jaw relation records
• Errors during transfer of the records to
  articulator
• Incorrect arrangement of posterior teeth
• Dimensional changes during curing
• Processing faults..

16

• Why is it difficult to detect occlusal errors in
  the mouth?
• Negative attitude (assume an error exists and try
  to find it)

17

• What is the ideal occlusal contact?
• At first contact, even maximum intercuspation at
  CR without denture shifting or instability
  without pain

18
Types of Occlusal Errors

• CO not coincide with CR
• Premature contact (high point) in one or both
  sides
• Uneven distribution of occlusal contacts
• Eccentric movement prematurities (protrusive
  lateral)

19
What are the Methods of Detecting Occlusal
Errors?

• Touch slide method (Refer to lecture 9)
• Denture dislodges or shifts when pt occludes
• Pt complains of pain beneath denture bases

20
Correction of Occlusal Errors

1. Laboratory remounting
2. Clinical remounting
3. Direct intraoral correction

21
Laboratory Remounting

• Disadvantages
• Cannot correct errors made while recording jaw
  relations
• Cannot correct errors made while mounting the
  casts on the articulator
• Does not compensate changes caused by settling of
  the denture bases

22
Clinical Remounting with New Interocclusal
Records

• Advantages
• Correct errors made during recording of jaw
  relations, or while mounting cast on articulator
• Less chair side time
• Corrections away from the patients view
• No saliva which makes detection by articulating
  paper difficult
• No shifting of dentures or incorrect closure by pt

23
The Aim of Clinical Remounting

• The prematurities are ground until multiple,
  uniformly distributed and even contacts are
  obtained bilaterally

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• Clinical remounting is currently the most
  commonly preferred method of occlusal correction

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Clinical Remounting Procedure

• Ask patient to bite on cotton rolls for 10 min.
• Guide mandible into CR several times.
• Bite registration material is placed on the post.
  teeth of the mandibular denture

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Clinical Remounting Procedure

• Guide mandible into CR
• Obtain interocclusal record of CR.

27
Clinical Remounting Procedure

• Mount upper denture using remounting jig
• Mount lower denture

28
Clinical Remounting Procedure
29
Selective Spot Grinding
The art of reducing premature contacting
surfaces, so that an equal pressure exists at all
points with interference at no point.
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How to Recognize Premature Contacts?

• A dark ring with a light center usually denotes a
  premature contact
• You should distinguish betw. marks made by normal
  occlusal contacts and those of premature contacts
• Articulating paper should not be reused many
  times and should be changed often.

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Selective Spot Grinding

• Make grinding until even (same intensity),
  stable, and multiple marks spread over wide area
  in both sides

32
Eliminating Occlusal Errors

• Re-establishment of CO.
• Correction of protrusive relation.
• Correction of working side occlusal errors.
• Correction of balancing side errors.
• Initially, centric occlusion errors are
  corrected, followed by protrusive, R L lateral
  interferences.

33
Basic Tooth Positions
Balancing Contacts
Centric Occlusion
Working Contacts
34
Selective Grinding Rules to Obtain CO

• After the first few taps on the articulating
  paper only a few high contacts appear.
• The marking process and the grinding are repeated
  until all except the anterior teeth contact in
  CO.
• Ideally all holding cusps of the maxillary and
  mandibular posterior teeth will make
  simultaneous contacts.
• It is not uncommon for one or two functional
  cusps not to make contact after establishing the
  final CO.
• It is not necessary to continue adjusting until
  these cusps make contacts because aggressive
  adjustment will sacrifice the established OVD

35
Selective Grinding Rules to Obtain CO

• As far as possible, avoid grinding cusp tips
  especially centric holding cusps, instead grind
  the opposing fossae or marginal ridges where the
  centric holding cusps occlude
• If the high contact is on the centric holding
  cusp inclines, the cuspal inclines can be
  reduced, thereby gradually moving the contact
  more toward the bearing cusp tip.
• A centric holding cusp may be reduced when it
  interferes with another centric holding cusp or
  when makes interferences in centric and eccentric
  positions

36
Re-establishment of CO
Problem Teeth too long Solution Deepen the
fossae
37
Re-establishment of CO
Problem Teeth too nearly end to end Solution
Grind Inclines
38
Re-establishment of CO
Problem Too much horizontal overlap Solution
Broaden central fossae
39
After the CO re-establishment.

• DO NOT
• Reduce maxillary lingual cusps.
• Reduce mandibular buccal cusps.
• Deepen the fossae.

40
Correction of Protrusive Relation

• The teeth are brought edge to edge
• Any interferences to smooth anterior gliding of
  dentures are eliminated by grinding
• Elimination of protrusive interferences along a
  path of 3 to 5 mm is sufficient

41
Correction of Working Side Occlusal Errors

• BULL rule
• buccal upper-lingual lower

42
Correction of Working Side Occlusal Errors

• Reduce lingual inclines of buccal cusps of upper
  teeth.
• Reduce buccal inclines of lingual cusps of lower
  teeth.
• ON WORKING SIDE ONLY!!!

43
Correction of Working Side Occlusal Errors
Problem Buccal and lingual cusps too
long. Solution Change inclines of balancing
cusps.
44
Correction of Working Side Occlusal Errors
Problem Buccal cusps are too long Solution
Change lingual incline of maxillary buccal cusp
45
Correction of Working Side Occlusal Errors
Problem Lingual cusp too long. Solution Change
buccal incline of lingual cusp of mandibular
tooth.
46
Correction of Balancing Side Errors

• On the balancing side, the cusps usually involved
  are the functional cusps and therefore grinding
  becomes more confusing

47
Correction of Balancing Side Errors

• Decide which supporting cusp maintains CO and
  reduce its opponent.

48
Correction of Balancing Side Errors

• Grind the lingual incline of the mandibular
  buccal cusp.

49
Direct Intraoral Correction

• Disadvantages
• Requires a lot of pt cooperation
• Pt should have good neuromuscular control
• Saliva
• Inaccurate closure by pt
• Misleading due to resiliency of tissues and
  shifting of denture bases

50
References

• Boucher's Prosthodontics Treatment for Edentulous
  Patients. Twelfth Edition.Chapter 20.
• Dalhousie continual education
• Complete Denture Prosthodontics, 1st Edition,
  2006 by John Joy Manappallil, Chapter 19