9- Denture placement and occlusion correction.

Dr. Amal Fathy Kaddah
Professor of Prosthodontics,
Faculty of Dentistry,
Cairo University

 Clinical errors
 Technical errors
 Inherent deficiencies in the material itself
Introduction
Causes of Denture 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
Clinical Errors

Processing and Technical faults
Distortion due to improper flasking
 Failure to close flask completely
 Too much pressure while closing the flask from the flask
press
 Tooth movement during flasking or packing
 Failure to cool flask before deflasking
Warpage due to overheating during polishing

Technical discrepancies could be due to:
1- Dimensional Changes in the wax due to variation in
temperature.
2- Expansion of the investing material during the
processing (plaster and dental stone ).
3- Errors which may occur during packing of acrylic
resin.
4- Changes in the acrylic resin material during
processing procedures (polymerization shrinkage).

Types of Occlusal Errors
 C.O. not coincide with C.R.
 Premature contact (high point) in one or both
sides
 Uneven distribution of occlusal contacts
 Eccentric movement prematurities (protrusive &
lateral)

Why is it difficult to detect occlusal
errors in the mouth?
*Shifting of denture bases, incorrect closure by
patient
* Resiliency of the Soft tissue
* Negative attitude (assume an error exists
and try to find it)

How can you Detect Occlusal Errors?
 Denture dislodges (instability) or shifts when
patient occludes
 Patient complains of pain beneath denture bases
>> worst by time
 Sliding of denture bases or uneven pressure
caused by faulty occlusion can lead to ulceration
of mucosa.

Cervical necks tilt posteriorly from the central incisor to the canine

• The appropriate Curve of Spee should be
incorporated into the setup.
• Make sure the posterior mandibular teeth are
centered over the ridge

• The plane of occlusion should be parallel to the body of
the mandible and extends from the incisal edges of the
central incisors and the middle portion of the retromolar
pads bilaterally.

Fabrication of Occlusal index for clinical
remounting
• At the end of the try in stage where the dentist
and patient are both satisfied.
• This is a time save procedure for you because you
do not have to make a new facebow record at the
time of delivery.

Place the Facebow remount jig on the lower member of
the articulator. Verify that the incisal guide pin is set at
zero. Allow plaster index to completely set. Verify that
the maxillary teeth can be repositioned into the
indentations.
Occlusal index for clinical
remounting

To save the position of the
maxillary cast
No need for face bow record in
the clinical remounting step

- During deflasking: be careful to preserve the cast, also
do not left or remove the denture from the casts
 Clean the denture and cast from plaster.
 Remove any stone or bubbles from the exposed
acrylic resin and from the occlusal surfaces of the
teeth.
 Remove any particles of stone from the base of the
cast and index grooves.
 Using a stiff brush, soap and water clean the denture
and cast before starting the laboratory remount

Dentures being re-mounted on the original articulator and
adjustments carried out to provide correct articulation (Laboratory
Remounting).

* Laboratory Remounting
Carried out, after defalsking and before
polishing of the denture, (before the
dentures are delivered to the patient), for
perfection of occlusion.
Occlusal discrepancies may result from
technical discrepancies.

Purpose
• To correct errors in occlusion that have
occurred during processing
• To return dentures to the correct vertical
dimension
• To obtain a smooth even contact of the teeth
in centric and eccentric positions.

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

The processed denture on the master cast is
repositioned to its old position on the articulator
by means of remounting indices made in the
master cast before mounting.

Remount and Adjust for Processing Errors

 The condylar elements of the articulator are
locked in the centric relation and the articulator is
closed.
 The incisal guide pin not
contact the incisal guide
table, The occlusal vertical
dimension has been changed
and must be re-established.

• Place red articulating paper between the
teeth and gently tap the teeth together in
centric occlusion.

The adjustment in centric occlusal position should be
stopped when widespread Contacts are produced.

The incisal guide pin usually stays in contact
with the incisal guide table.

The adjustment in eccentric occlusal positions

The adjustment in eccentric occlusal positions should be stopped when
widespread Contacts are produced and the incisal guide pin usually stays in
contact with the incisal guide table.

The Aim of Laboratory Remounting
The prematurities are ground until multiple,
uniformly distributed and even contacts are
obtained bilaterally
The incisal guide pin stays in contact the
incisal guide table

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)

What are the Methods of Detecting
Occlusal Errors?
• Denture dislodges or shifts when patient occludes.
• Patient complains of pain beneath denture bases.
Correction of Occlusal Errors:
• Laboratory remounting.
• Clinical remounting.
• Direct intraoral correction.

a . Adjustment of Processing Error .
b . Finishing and Polishing of Denture.
1. PRE-INSERTION PREPARATION
2. INSERTION VISIT
1 . Re-examine dentures and foundation tissues.
2 . Insert each denture independently.
3 . Occlusal equilibration to be accomplished at this time.
a . Clinical Remount of the upper cast.
b . Interocclusal records - waxes.
c . Remount the lower denture.

Correcting occlusal errors in
patient's mouth
Articulating paper in the mouth
. Not give accurate indication due to the resiliency
of the supporting tissues
Adhesive Wax

Clinical remount
Dentures should be remounted with new
records obtained from the patients
Mount the upper cast according to a face-bow
record or occlusal index * and Mount the lower
cast according to a new centric relation record.

Advantages of Clinical Remounting with New
Interocclusal Records *
 Less chair side time
 Corrections away from the patient’s view
 No saliva which makes detection by articulating
paper difficult
 No shifting of dentures or incorrect closure by patient

The Aim of Clinical Remounting
The prematurities are ground until
multiple, uniformly distributed and
even contacts are obtained bilaterally

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

Fabrication of Remount casts at the
time of delivery
Block out undercut areas in the tissue
surfaces before pouring the plaster

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 posterior teeth of
the mandibular denture

 Guide mandible into CR
 Obtain the new interocclusal
record of C.R. using your
recording medium of choice,
making sure that the teeth do
not touch. ???

Do I need New Face bow
RECORD?????????
Remount upper denture using
remounting jig

Mounting the lower cast with new CJRR
Make sure that the denture bases are not contacting posteriorly.

‫مقابل‬‫بال‬ ‫أعطيت‬‫كلما‬
..
‫توقع‬‫بال‬‫قت‬ِ‫ز‬ُ‫ر‬‫كلما‬
‫هادئ‬ ‫بصوت‬ ‫الخير‬ ‫اعمل‬
‫مرتفع‬ ٍ
‫بصوت‬‫عملك‬‫يتحدث‬
ً
‫فغدا‬

I. Selective grinding
II. Milling XXXXX
The procedures of Perfection of occlusion

Selective Spot Grinding
* Reducing premature contacting surfaces, so
that an equal pressure exists at all points with
no interference

The buccal cusps of the mandibular posterior teeth and
lingual cusps of maxillary teeth are called supporting
cusps.
These cusps occlude in central fossa and maintain the
occlusal vertical height.
They also called centric cusps and holding cusps.
Supporting cusp or Functional Cusp
The lingual cusps of mandibular posterior teeth and buccal cusps of the
maxillary posterior teeth called guiding cusps.
They guide the mandible in lateral movements.
Non Functional Cusps

Note that the stamp cusps
(those fitting into the
central portion of the
opposing teeth)
compromise 60% of the
total faciolingual tooth
dimension.

Basic Tooth Positions
Balancing Contacts Centric Occlusion Working Contacts
Ideally all holding cusps * of the maxillary and mandibular
posterior teeth will make simultaneous contacts.

How to Recognize Premature Contacts?
A dark ring with a
light center
usually denotes a
premature contact

 You should distinguish between
marks made by normal occlusal
contacts and those of premature
contacts
How to Recognize Premature Contacts?
 Articulating paper should not
be reused many times and
should be changed often.

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

*Eliminating Occlusal Errors
(selective grinding)
Procedures of

The sequence of steps should be as follows
 Restore the vertical dimension
 Re-establishment of C.O.
 Correction of working side occlusal errors.
 Correction of balancing side errors.
 Correction of protrusive relation.

• The condylar elements of the articulator are locked in
the centric relation and the articulator is closed.
• Grind the teeth with small diamond stones.
• Use red articulating paper to mark the area of
premature contacts for making centric occlusion and
blue articulating paper for the eccentric movements
1. Adjust the articulator to the proper setting

• Lock the upper arm of the articulator in centric
relation. Check the occlusion by opening and
closing the articulator.
• Place red articulating
paper between the teeth
and gently tap the teeth
together in centric
occlusion.

2. Establish the occlusal vertical dimension in
centric:
Occlusal VD is maintained by
occlusion of palatal upper cusp and
buccal lower cusp
(in normal occlusion)
( Supporting cusps)

a. If the cusp is high in centric and eccentric relation,
reduce cusp.
b. If the cusp is high in centric but not eccentric,
deepen fossa.

Correction of occlusion done by reducing buccal incline
of upper Lingual cusp and Lingual incline of lower buccal
cusp or deepening their corresponding fossae
p
B

• Do not grind the cusp tips
unless it is high in every
excursion, but rather
reduce the fossa or
inclined plane of the cusp.
3- Re-establishment of C.O.

Problem: Teeth too nearly tip to tip
(If insufficient overjet)
Solution: Grind Inclines
- Grind the inner inclines of upper buccal & lower lingual Cusps.
- Grind lingual incline of upper lingual cusps.
- Grind buccal incline of lower buccal cusps.
So that the cusp tips contact the central fossae.
The cusp tips should not be shortened.
Re-establishment of CO

Problem: Too much horizontal overlap(upper teeth too far buccaly
to lower ones)
Solution: . Broaden central fossae
• Grind the inner inclines of upper lingual cusps &
lower Buccal cusps.
Re-establishment of CO
The cusp tips should not be shortened.

The adjustment in centric occlusal position should be
stopped when widespread Contacts are produced

Reduce the teeth until the incisal pin touches the
incisal guide table and uniform contact exists on
all posterior teeth.
Anterior teeth should not touch in centric occlusion.

After the CO re-establishment
 DO NOT Reduce maxillary lingual cusps.
 DO NOT Reduce mandibular buccal
cusps.
These cusps are essential to maintain the
recorded vertical dimension
 DO NOT Deepen the fossae.

Loosen the locks on the condylar elements and
move the denture in eccentric movements. Using
blue articulating paper between the teeth.
4. Refine occlusion in eccentric

The adjustment in eccentric occlusal
positions

The adjustment in eccentric occlusal positions should be
stopped when widespread Contacts are produced and the
incisal guide pin usually stays in contact with the incisal
guide table.

• If the cusp contacts
prematurely on closure as
before, but is not premature in
lateral excursions, the fossa is
deepened
• Prematurely contacts in
centric and in lateral
excursions, the cusp is
reduced in height.

a- Lateral movement:
i. On the working side:
Follow "Bull rule" of reducing buccal upper and lingual
lower cusp inclines.
b. Protrusive movement:
Bull rule does not work. Reduce interceptive cusp as
shown by the carbon paper. Decide which supporting
cusp maintains CO and reduce its opponent.
ii. On the balancing side:
Reduce distal inclines of maxillary cusp and mesial
inclines of mandibular cusps

• Reduce lingual inclines of buccal cusps of
upper teeth.
• Reduce buccal inclines of lingual cusps of
lower teeth.
ON WORKING SIDE ONLY!!!
i- "Bull rule on the working side "

Problem: Buccal
and lingual cusps
too long.
"Bull rule on the working side "

Adjustment Rule:
Buccal inclines of the lingual upper cusps .
lingual inclines of the buccal lower cusps .
LUBL
ii. Correction of Balancing Side interferences
Occurs between the lingual upper
and buccal lower supporting cusps
Which are the functional cusps

ii. Correction of Balancing Side Errors
Decide which supporting cusp maintains CO
and reduce its opponent.

If interference exists on the balancing side Grind the lingual
incline of the mandibular buccal cusp.
It is a centric holding cusp so grind carefully and do not
reduce the cusp tip.
Correction of Balancing Side interferences

a. If the anterior teeth have heavy contact with no
contact on the posterior teeth grind the labial
surface of the lower anterior and the palatal surface of
the upper anteriors.
b. If heavy posterior contact exists with no anterior
contact reduce the distal inclines of the
maxillary cusps and the mesial inclines of the
mandibular cusps.
b- Correction of Protrusive Relation

In protrusive excursion, premature contacts are
eliminated by grinding the distal facing inclines of
upper teeth and mesial facing inclines of lower
teeth.
DUML
Adjustment Rule:

Proceed with selective grinding
until you get balance at centric
contact and occlusal harmony in
eccentric movements

Briefly
BULL rule in:
-Working side interferences.
LUBL rule in:
-Non-working side interferences.
DUML rule in:
-Protrusive interferences.

Direct Intraoral Correction
 Requires a lot of patient cooperation.
 Patient should have good neuromuscular control
 Saliva.
 Inaccurate closure by patient.
 Misleading due to resiliency of tissues and
shifting of denture bases.
Disadvantages

Direct Intraoral Correction
• Check for the coincides of maximum intercuspation
with centric relation position, and whether the
vertical dimension of occlusion is unchanged or not.
• Only small discrepancies in maximum
intercuspation, can be adjusted following the same
rules as for correcting occlusal errors on the
articulator.

Rules for selective grinding:
1. Never grind a centric cusp tip unless it contacts prematurely in all excursions
of the mandible. Always grind the opposing fossa or marginal ridges where
the centric holding cusps occlude.
2. Utilize the BULL rule when perfecting working occlusion, For interference in
the posterior teeth reduce the upper buccal cusp slopes and the lower lingual
cusp slopes.
3. When grinding to perfect balancing occlusion never grind the interfering cusp
tips but grind the cusp inclines.
4. In correcting protrusive interference in the anterior teeth grind on the labial
portion of the incisal edges of the lower teeth and the lingual portion (palatal
surfaces) of the upper teeth.
5. In protrusive balance, the anterior teeth should make incisal edge contact at
the same time that the tips of the buccal and lingual cusps of the posterior
teeth contact.

Balance occlusion in Working side,
Balancing side, Protrusive position

II- Digital methods
Digital technology helps clinicians to
identify premature contacts, high
forces, Timing and interrelationship of
occlusal surfaces.

T-Scan is an objective assessment tool used
to evaluate the occlusion of a patient.
Unlike articulating paper, which can only
determine location,
T-Scan can identify both force and timing,
two of the most fundamental parameters for
measuring occlusion.

II. Milling XXX (Obsolete)
A small amount of carborubdum abrasive
paste is placed over the lower teeth and the
articulator is closed in centric position.
Several movements are made from centric into
each eccentric position to eliminate any slight
interference

Remounting has the following
advantages
1- Reduce patient's participation.
2- Allow for better visualization.
3- Provides a stable working foundation.
4- More accurate markings with the articulating
paper in absence of saliva.

3. POSTINSERTION CARE
1 . First appointment within 48 hours of delivery .
2 . Second appointment within 3 days .
3 . Third appointment within 1 week of 2nd visit .
4. CASE COMPLETION
1 . Patient able to masticate food .
2 . Patient should present a normal individual appearance .
3 . Patient should be able to speak distinctly .
4 . Patient should experience oral comfort .
5 . Patient should be educated as to the need for periodic
examination .
5. RECALL

References
1. Boucher's prosthodontics treatment for edentulous patients. Twelfth Edition.
Chapter 20.
2. Complete Denture Prosthodontics, 1st Edition, 2006 by John Joy Manappallil,
chapter 19
3. Dalhousie continual education
4. Denture placement & patient education - dr.Rola shadid
https://drrolashadid.Weebly.Com/uploads/1/4/9/4/14946992/lecture_10_1.Ppt
5. Https://wsdav6.Squarespace.Com/s/i-hate_love-complete-dentures-ronnie-
schnell.Pdf
6. John Beumer III, DDS, MS: 24. Refine Denture Setup Division of Advanced
Prosthodontics, Biomaterials and Hospital Dentistry UCLA School of Dentistry
7. Washington state dental association's 2015 pacific ... - WSDA

Verify centric relation
• Insert dentures and hold lower in
position with your index fingers;
• Retrude the mandible and close into
centric relation.
• Observe any shift in the upper denture.
• Look for even contact of the posterior
teeth bilaterally.
Note the separation of the posterior
teeth in CR. This patient’s centric
relation is incorrect
Clinical Remounting Procedures using compound

• Soften a stick of compound over ta
Bunsen burner.
• Place the compound onto the occlusal
surfaces of the mandibular posterior
teeth.
• Temper the compound in a water bath
set at the proper temperature, (1100) and
smooth it with your wet gloved finger.
(1400) if green stick compound is used.)
Verify centric relation

• Recline the chair back, this will help
retrude the mandible.
• Stabilize mandibular base with your index
fingers on the buccal flange and the
thumbs under the mandible (bimanual
technique).
• Rehearse closing with the patient.
• Have patient gently close into the
compound just short of tooth contact.
Make centric relation record

If the teeth do not contact the index exactly,
remount the mandibular cast.
• Loosen the condylar locks.
• Set the teeth in the index.
• Drop the pin so that it contacts the table.
• Tighten the set screw.
• Remove the mandibular cast.
• Lock the articulator in centric.
• Remount the mandibular cast to the new record.
• Raise the pin so the teeth contact.
• Tighten the set screw at that point.

Mother Tereza
If you want to
change the
world, go home
and love your
family.

9- Denture placement and occlusion correction.

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