Clinical and Laboratory Remounting with Selective grinding

2. Clinical and Laboratory Remounting
in Complete Dentures
Submitted by:
Dr.Pallavi Chavan
2nd year PG

3. Introduction
• Complete dentures are prosthetic replacements for lost
natural teeth and lost soft and bony tissues, which are
fabricated in order to restore impaired or lost functions and
appearance
• Fabrication of complete dentures comprises various variables
whose precise execution is of crucial importance for
achieving success with fabricated dentures

4. • The efficiency and comfort that a patient experiences using
complete dentures depends to a large extent on the harmony
of the occlusion
• Occlusion established during try-in stage is subject to change
because of inaccuracies incorporated during construction of
dentures

5. • Minor faults can be corrected by selective grinding with
dentures in patient's mouth, if a split cast remount procedure
was used immediately after the dentures were processed.
• However, a general dental practice survey revealed that less
than 5% of dentists use the split cast procedure to rectify the
errors of processing

6. • Prosthodontist’s recommend a remount procedure for
identification and correction of occlusal errors in complete
dentures rather than the more common practice of placing
the articulating paper intra orally, followed by spot grinding
at the chair side
• However, There is no evidence to support such
recommendations

7. What is Remounting??
Definition:
• Remount procedure :
Any method used to relate restorations to an articulator
for analysis and/or to assist in development of a plan for
occlusal equilibration or reshaping.
• Remount record index :
A record of maxillary structures affixed to the
mandibular member of an articulator useful in facilitating
subsequent transfers

8. Causes of Errors in Occlusion :
1. Incorrect Registration of Centric Occlusion:
• Reason A :
▫ During JR, when occlusal rims are brought together cause
uneven pressure due to premature contact in the 2nd
molar or incisor region
▫ Compression of mucosa
▫ Displaces the mucosa away from the region of premature
contacts

9. But, on plaster models there is no compression of tissues
Thus, different relation in mouth and articulator
Thus, an error is established which is passed through try-in
and processing stages
At denture insertion the dentures contact only in areas of these
premature contacts
Causes of errors in occlusion

10. Incorrect registration of centric occlusion
• Reason B:
▫ Imperfectly fitting record bases can cause movement of rims
while recording centric
▫ The dentures will have slightly inaccurate centric occlusion
relation and will tend to move on the ridges , causing soreness
• Reason C:
▫ The models may not be placed accurately on the articulator
while mounting
Causes of errors in occlusion :

11. 2. Irregularities in Teeth Setting :
• Difficult to set perfectly even contact in teeth arrangement
leading to some heavy contacts /pressure
• Wax has certain resiliency ,permits tooth movements to
occur when interferences are encountered unlike hard
acrylic in denture
• Wax can contract and move ,causing irregularities in teeth
arrangement
Causes of errors in occlusion :

12. 3. Tooth movement while Flasking and Packing
• Tooth movement while de-waxing
• Excessive packing pressures results in, the artificial teeth
being forced into the investing plaster
• If the acrylic resin has reached an advanced dough stage
• Normal packing pressures when the investing mix is weak
can break the mould
Causes of errors in occlusion :

13. 3. Tooth movement while flasking and packing
• Incomplete Flask closure
• If pressure on the flask is released during the curing cycle
• Separation of the two halves of the flask by a layer of excess
resin which should have been removed during trial closure
of the flask(flash)
Causes of errors in occlusion :

14. In spite of taking all due precautions to prevent the
errors just described, small occlusal inaccuracies
invariably occur.
These errors can be corrected in the laboratory if a split-cast
mounting technique is used.
An average increase in height of 0.5 mm and a shift
in tooth contact towards the posterior region
T. Badel et al . Complete Denture Remounting ;Acta Stomatol Croat, Vol. 35, br. 3, 2001

15. 4. Articulator wear:
• All articulators are subjected to wear and older and more
worn the articulator the greater will be the error in occlusion
and articulation
• Every piece of mechanical apparatus exhibits some play in its
moving part and when this becomes easily detectable, the
bearing should be replaced

16. 5. Other factors
• Over heating during polishing procedures
• Inevitable dimensional changes in the denture material
during and after polymerisation
• Expansion of the acrylic resin due to water absorption
Shrinkage in denture makes the cuspal position Change in
turn increasing VD.

17. Occlusal errors can be corrected by:
Direct correction in mouth
Laboratory remounting
Clinical remounting

18. Direct Correction in Mouth
1.Articulating paper
▫ It will not give an accurate indication of premature
contacts because of resiliency of supporting tissues
that allows the denture to shift producing markings
which are frequently false

19. 2. Central bearing plates:
• The correlator:
▫ It has a spring loaded central pin
▫ It contacts a metal plate in the
vault
▫ This,hold the maxillary denture
up and mandibular denture
down
▫ At a premature contact,the
dentures do not shift because the
spring holds the teeth apart
• Coble device:
▫ Has a central bearing pin
without spring
Coble device

20. 3.Occlusal waxes:
▫ Adhesive wax is added on the mandibular denture
▫ Points of penetration are observed and relieved
• Advantage :
▫ Can locate interference in functional movements
• Disadvantage:
▫ Can give false reading due to shift of underlying soft tissues

21. 4.Abrasive pastes:
• Should only be used to refine occlusion after selective
grinding on articulator
• Disadvantages:
▫ Shifting bases cause premature contacts
▫ Cusps maintaining vertical dimension might be destroyed

22. When to do Remounts ??
#1Wax—up
If the wax-up
occlusion is
different in
mouth compared
to the
articulator
#2 Processed
After processing
the VDO is
increased
To get back to the
original VDO
#3Delivery
Inaccurate
occlusion from
all previous steps
not eliminated in
prior remount

23. Laboratory Remounting:
• Purpose:
1. To correct errors in processing
2. To return dentures to the correct vertical dimension
3. To restore centric and bilateral balanced occlusion

24. • After processing, but before the removal of the dentures from
their casts, they are returned to the articulator.
• This is accomplished by using split-cast mounting
techniques, which allow easy location and removal of the
cast from its mounting plaster on the articulator.
Split Cast mounting technique:
1.procedure for placing indexed casts on an articulator to facilitate
their removal and replacement on the instrument;
2. the procedure of checking the ability of an articulator to receive or
be adjusted to a maxillomandibular relation record.

25. • Split-cast mounting is carried out in the laboratory, by
notching the base of the cast and applying separating
medium just before articulating the casts.
• The cast is easily separated from the mounting plaster and is
flasked after the try-in.
• The cast can be removed from the flask and reattached to the
mounting plaster using cyanoacrylate glue.

26. Split Mounting Plates
Plexi glass with embedded split mounting
plate part
Split mounting plate has 3 metal
plates and a pin
Opposing section of split plate attached to the embedded section

27. Split Mounting Plates :
Pin removed ; plexiglass detached and
other section of split plate attached to cast
Impression is boxed and poured and
plexiglass is positioned on it

28. Masking tape wrapped around cast
on the articulator
The boxing is filled with plaster
Tapered pin is removed and cast seperated

29. Procedure for Laboratory Remounting
After Remounting ,check the incisal pin
and incisal table contact (1-3mm)
Check contacts between heals of the casts
and dentures
Place articulating paper ,and gently tap
After the centric check eccentric and
protrusive contacts
Adjust these contacts by selective teeth
grinding

30. Clinical Remounting
• It consists of remounting the finished denture on an
articulator by using new inter-occlusal records in the
patients mouth
• The purpose of clinical remounting is to accommodate the
errors made during centric relation records

31. Advantages :
1. It reduces patients participation
2. It permits the dentist to see better what he /she is doing
3. It provides stable base ,eliminating the resilient tissues
4. Absence of saliva makes markings more accurate

32. Steps for Clinical Remounting
I. Registration of centric relationship without tooth contact
II. Lateral or protrusive records
III. Facebow registration
IV. Mounting the dentures
V. Correcting the occlusion by spot grinding

33. I. Registration of Centric Relationship without
Tooth Contact
• Easily and quickly
heat softened
• Records can be
modified changed,
corrected and
verified with
comparative ease
• Can distort
• Care while handling
Aluwax
• Records of
impression
plasters are
accurate, rigid
after setting
difficult to
handle
• brittle
POP
• Accurate
• Stable
• Do not need a carrier
• Not enough working
time
• Resistance to
compression on setting
Silicones

34. Remounting at Increased Vertical
Dimension or Correct Vertical
Dimension??
• When the vertical discrepancy is 2 mm or less, we are often
tempted to record the new interocclusal record at the same
vertical
• But,when even one tooth makes contact on one side ,it can
shift the bases and cause inaccurate records.
Steps for clinical remounting

35. • Therefore,
• The remounting records are made at higher vertical
dimensions
• i.e :if 2 mm of error + 1-2 mm of material space = 3-4
mm of increased vertical dimension
• This increase should be nullified back,to the original vertical
dimension by grinding
Steps for clinical remounting

36. • Occlusal errors at wax try-in stage can be corrected by
removing the interfering tooth/teeth
• New interocclusal record is then made at the same vertical
dimension
• This is a more accurate and physiologically appropriate
method
Steps for clinical remounting

37. Procedure for Interocclusal Record
without Tooth Contact
• Two aluwax doubled layered strips (1/2”) are immersed in
water bath of 540c for 30 sec.
• Maxillary denture is seated in mouth, followed by
mandibular and stabilized with the index finger over buccal
flange area.
• Then the Mandible is guided into CR
closing lightly into the wax.
Steps for clinical remounting

38. • As contact with the wax approaches the fingers are removed
and the patient is instructed to close into the wax until a good
index is made
• The imprints of opposing teeth must be crisp and 1mm deep
with no penetration of wax record by opposing teeth
If the teeth make contact ,the lower cusp will
guide the mandible to the previous wrong
position of occlusion ,thus preventing the
desired correction
Steps for clinical remounting

39. III. Facebow Registration:
• Sufficient amount of wax is adapted on the prongs of
facebow fork
• The patient closes on the fork , facebow is then attached to
the fork and related to the condylar heads
Why facebow???
A facebow is used to record the relationship of the
upper denture to the patient's mandibular hinge axis
and transfer this to an articulator, using the hinge axis
of the articulator as a reference.
If a facebow is used it allows the teeth to contact by
rotating about an arc of closure identical to that of the
patient.
A facebow is therefore often used to remount the
processed dentures on an articulator for the correction
of occlusal errors
Steps for clinical remounting

40. IV. Mounting Dentures in Adjustable Articulators
• Fabrication of clinical remount casts:
▫ Serve as an accurate, convenient and time saving
method of reorienting the completed dentures on
articulator for occlusal correction
▫
All undercuts on the tissue surface of the dentures are filled with wet
tissue paper, pumice
Steps for clinical remounting

41. Fast setting plaster or dental stone is poured into
the denture
Steps for clinical remounting

42. The maxillary remount cast is attached to the maxillary
member of the articulator using the facebow transfer jig
Steps for clinical remounting

43. Fabrication of the Facebow Transfer Jig
Attach upper processed
denture to the upper
mounting ring
Pour fast setting plaster
on the lower ring
Press the teeth in the
plaster
Steps for clinical remounting

44. Mounting for Clinical Remount
 The remounting jig and the index are positioned on the
mandibular member of the articulator,
 The maxillary denture and the remounting casts are placed
in plaster indentation.
The maxillary cast is attached to upper member of the
articulator with plaster
The lower denture is attached to the upper denture with help
of wax interocclusal records
Steps for clinical remounting

45. The condylar guidance can be set with the help of protrusive
and lateral records
After the plaster is set,the incisal guide pin is tightened and
the record is removed ,there should be no contact of teeth
The incisal pin is then removed and occlusion is set by
selective grinding procedure
Steps for clinical remounting

46. A simplified Chairside Remount Technique
using Customized Mounting Platforms
• This clinical remount technique utilizes maxillary and
mandibular CMPs (Customized Mounting Plates) that are
fabricated over mounting plates of articulator..
Boxed mounting plates
6.5mm
2 mm 2.5mm
Chauhan et al J Adv Prosthodont. 2012 Aug; 4(3): 170–173.

47. Horseshoe shaped grooves
U-shaped positive replica of edentulous
ridges with Acrylic (5-6mm)

48. Customized mounting platforms secured
on articulator
Remount casts obtained in putty
impression material.
Mounting done with centric interocclusal record.

49. V.Selective Grinding Procedure
• In order to produce a satisfactory result, it is important
to carry out grinding in a systematic way to:
oThe VD maintenance
oEven distribution of occlusal stresses in CO.
oEven distribution of occlusal stresses maintained in
lateral position.
Steps for clinical remounting

50. • Hammer and Anvil concept:
As an aid in determining where on the teeth adjustments are to
be made
Supporting cusps considered as Hammer
The portion of tooth contacted by them as Anvil
The rule is,
Adjust the anvil ,NEVER the hammer,thus
preserving our centric stops
The vertical dimension is controlled by these
cusps ,therefore they should receive special
consideration
Bailey DCNA April 1995 39(2)

51. Grinding in Centric
• The first objective is to remove premature contacts in
centric occlusion
• Mark the interfering cusps with articulating paper
• In the retruded contact position there are three types of
occlusal errors and each can be corrected by specific
grinding
1. Any pair of antagonist teeth can be too long and thus
hold other teeth out of contact’
2. The lower and upper teeth can be placed almost edge-
to-edge
3. The upper teeth can be positioned too buccally in
relation to the lower teeth.

52. 1. When cusps are too long:
1.If the offending cusp makes premature contact in centric
as well as eccentric ground the cusp
2.If the offending cusp makes premature contact in centric
only ,deepen the opposing fossa

55. 2. The lower and upper teeth can be placed almost edge-
to-edge
▫ Broadnening the central fossae:
 LINGUAL inclines of the UPPER BUCCAL cusps and
BUCCAL inclines of the LOWER LINGUAL teeth are
ground
▫ Narrowing the cusps:
 Reducing palatal inclines of upper palatal cusps
 Reducing buccal inclines of lower buccal

56. 3. The upper teeth positioned too buccally in relation
to the lower teeth
The palatal cusp is ground in the palatal direction and the
mandibular buccal cusp in the buccal direction so that
teeth can enter each other.

57. Grinding in Eccentric
• Free sliding eccentric movements are important to
▫ Reduce stress on ridges
▫ Retention
▫ stability
Rule for eccentric grinding is ….Always adjust that which is
moving

58. On the Working Side there are six types of
Occlusal Errors
1. The maxillary buccal cusp and the mandibular lingual cusp are
too long
2. The buccal cusps are in contact, but the lingual are not
3. The lingual cusps are in contact, whereas the buccal are not
4. The maxillary buccal or palatal cusps are positioned more
mesially from their intercuspal position
5. The maxillary buccal or lingual cusps are positioned more
distally from their intercuspal position
6. The teeth on the working side can be out of contact

59. 1.The maxillary buccal cusp and the mandibular lingual cusp
are too long
▫ The inner inclines of BUCCAL cusps of UPPER and
LINGUAL cusps of LOWER (BULL) are adjusted
2. The buccal cusps are in contact, but the lingual are not
▫ The lingual inclines of upper buccal cusps are ground

60. 3. The lingual cusps are in contact, whereas the buccal are not
▫ Buccal inclines of mandibular lingual cusps are reduced
4.The maxillary buccal or palatal cusps are positioned more
mesially from their intercuspal position(MU-DL)
▫ Mesial inclines of the UPPER buccal cusps
▫ Distal inclines of the LOWER buccal cusps

61. 5.The maxillary buccal or lingual cusps are positioned
more distally from their intercuspal position
▫ maxillary cusps distally and on the mandibular cusps mesially
6. The teeth on the working side can be out of contact
▫ This is because of intense contact on the balancing side

62. Occlusal Errors on the Non-working side
• Mandibular buccal cusp are adjusted to reduce the incline of
the part of the cusp that prevents tooth contacts on the
working side

63. Occlusal Errors in Protrusion
• Accoroding to Boucher If the lateral eccentric contacts are
corrected the protrusive grinding also have been
accomplished
• However,premature contacts on the incisors are corrected at
expense of Incisal edges of lower anteriors

64. Perfecting Articulation with Grinding
Paste
• The main correction of occlusal irregularities must be carried
out using a small mounted abrasive stone in a hand piece to
maintain VDO
• A paste of coarse grit carborundum powder mixed with
Vaseline/toothpaste is used followed by fine grit
carborundum to produce the even occlusal contacts
• The sharp edges occurring buccally and lingualy must be
rounded to prevent tongue and cheek irritation

65. Eliminating Occlusal Errors in Non-
Anatomic Teeth
• Maxillary posterior are flattened by sanding on ultrafine
sand paper against a truly flat surface
• After placing on the remount casts and articulation,occlusal
contacts are marked
• Selective grinding is done only on the mandibular teeth

66. Occlusal Adjustment in Average Value
Articulator
• Using a simple hinge articulator is not satisfactory, as lateral
excursions are not possible
• The retruded contact position is recorded intraoral using soft
wax
• The upper denture is articulated so that the center pin,
touches the mid-line at the upper incisal edge.

67. • The lower denture is attached to the articulator ensuring that
the occlusal plane is horizontal and parallel to the base of the
articulator
• When the plaster has set, the wax is removed between the
occlusal surfaces of the teeth and the occlusal adjustment is
carried out

68. Full Dentures Opposed to Partial Dentures
• When maxillary complete dentures and mandibular partial
dentures:
▫ Lower impression with the partial denture in situ
▫ When casting the impression RPD must be retained in it
▫ Similar procedures as previously mentioned are carried out
▫ Avoid grinding natural teeth

69. Partial Upper an Lower Dentures
• For maxillary and mandibular distal extensions with only
anterior teeth remaining previously described procedures
can be carried out
• For small partial dentures,the opposing natural dentition is
adjusted

70. Conclusion
• Correct occlusal relationships are a part of the success in
prosthetic treatment for edentulous patients with complete
dentures.
• A clinical remount procedure of the finished dentures is a
constituent part of prosthetic patient treatment in practice of
complete dentures.
• According to a study done by Kamal Shigli et al the results
indicated that the laboratory and clinical remount
procedures,along with occlusal corrections, reduced the
number of areas of tissue irritation, postinsertion visits, pain
during mastication and swallowing, and discomfort during
mastication, and enhanced the comfort of the patient

71. • The clinical remount also maintains the stability of dentures
when the mandible is in centric relation position
• Selective grinding helps to remove the occlusal errors in a
systematic way
• Occlusion of such dentures is more stable for longer time and
with less parafunctional movements
and Hence, a more Satisfied Patient

72. References :
• Syllabus of complete Dentures ;Heartwell 4th edition
• Prosthodontic Treatment for Edentulous Patients ;Zarb
,Hobkirk et al 13th edition
• Dental Laboratory Procedures volume 1 ;Rudd and Morrow
• Fenn, Liddelow, and Gimsons' clinical dental prosthetics
• Bailey et al Occlusal Adjustment ; DCNA april 1995 ;39(2)

73. • Chauhan et al A simplified chairside remount technique using
customized mounting platforms; J Adv Prosthodont. 2012 Aug;
4(3): 170–173.
• Tomislav Badel et al Complete Denture Remounting Acta Stomatol
Croat, Vol. 35, br. 3, 2001.
• Kamal Shigli The effect of remount procedures on patient comfort
for complete denture treatment J Prosthet Dent 2008;99:66-72
• Lang et al ;Complete Denture Occlusion ;DCNA 2004 48 :641—
665