Clinical Removable Prosthodontics Forth Year

1. Denture insertion
The finished denture must fulfill :
1. Physical needs required to perform adequate
function without trauma to supporting
structures
2. Physiologic needs to allow proper support by
muscles for good esthetics.
3. Psychologic needs to provide proper function
& esthetics .

2. Objectives :
1. To identify and correct :
-- Any area of denture base causing pain or discomfort.
-- Any area of denture interfering with retention & stability of dentures.
-- Any part of denture that is esthetically unpleasing
2. To modify occlusal surfaces to harmonize occlusion (refine occlusion )
3. To instruct the pt. how to use & care his denture .
4. To instruct the pt. in proper care of denture supporting tissues .
5. To advise the pt. on limitations of dentures to be expected

3. Spatula try-in
The well adapted rims
surfaces are paralels, lay
onto each other, and bases
are attached to the maxilla
and mandibule

4. Well adjusted rims

5. Transversal Christensen phenomenon
Means that when the patient bites with well-adapted occlusal
rims laterally, rims are in occlusion only on the workingside. On the balancing side an open, wedge-shaped gap
occurs at the molars, between the upper and lower rims.

6. Sagittal Christensen phenomenon
Means that when the patient bites with well-adapted occlusal
rims, an open, wedge-shaped gap occurs at the molars.

7. Insertion procedures :
1. Extraoral examination of the finished denture:
A. Examination of impression surface
B. Evaluation of denture borders.
C. evaluation of polished surface.
2. Intraoral examination of the finished denture :
A. Location & relief of pressure areas in denture base
B. Identification & reduction of overextended borders
C. Evaluation of retention & stability
D. Evaluation of esthetics & facial contours
E. Refinement of occlusion
F. Patient’s instructions

9. ARTCULATOR
PIP
Rubber bowl , mouth wash
Hand mirror
Completed dentures & study casts
Straight handpiece & burs
Occlusal indicating wax
Articulating paper
Mouth mirror & napkin

10. DENTURE ASSESSMENT
Testing maxillary denture retention
Apply a tipping force to the incisors in an attempt to break
seal.

11. Testing maxillary denture stability
Apply unilateral force to posterior occlusal surface of
denture.

12. Testing stability and retention of
mandibular denture
Alternately apply unilateral force to posterior occlusal
surfaces.

13. Removal of sharp edges & roughness as they will traumatize
mucosa because dentures in function are continuously shifting

14. Prior to insertion , denture fitting surfaces must be inspected by
palpation & any sharp projections must be ground

15. Checking labial notch
As the denture is seated ,labial frenum is too narrow & shallow

16. Avoid sharp edges when trimming labial frenum notch .
Frenum must be able to “ roll over” the denture

17. If stretched cheek is released , buccal frenum will lie tightly
against functional border of the denture. As mouth is opened ,
buccal frena are stretched back & down. So, frena contribute to
a well adapted border

18. To check retention of upper denture , pull down with 2 fingers .
As denture moves down, then holds well, air is trapped under
denture base upon insertion.
To check retention of lower denture , push gently against lower
anteriors with closed pliers as tongue filling floor of the mouth

19. Retentive denture is removed by breaking border seal with index fingers or
by pulling out the cheeks
Demonstrating masticatory stability when a closing force is exerted in the
area of posterior teeth

20. Cleaning the dentures
Denture brushes are advised ( specially important for elderly
& disabled pt. )

21. Pt. must not hold lower
denture using a squeezing
action during cleaning
Recommended method to
hold a lower denture during
cleaning

22. Pt. must not use hot water ( above 70 C ) to clean
dentures. Elevated temperature crazes the denture
surface resulting in a bleached appearance.

23. Upper denture with a clear palate. It enables areas of high
pressure under the denture to be seen & preferred by some
pts. due to its lighter appearance

24. PIP is used to identify areas on fitting surfaces of dentures ,
which exert heavier pressures on the tissues

25. Thin layer of PIP is painted
on denture fitting surface
Denture is seated in mouth
& removed . Areas of high
pressure are identified

26. Dynamic relationships of teeth as the jaw is moved to right & left
and when protruded . This is checked with articulating paper of a
different color

27. Pattern of occlusal contacts produced by sliding the mandible to
the right ( working side ) & the left as the balancing side . Even
occlusal contacts , such as those , are produced by grinding cusps
.

28. Occlusal indicator wax may be used instead of articulating
paper to indicate the location & extent of occlusal
contacts , or near contacts .

29. Wax has a shiny , mildly adhesive coating on one side .
Pencil is used to mark the teeth where the opposing arch is
penetrating the wax

30. Areas of heavy tooth contact will cause penetration of wax , that allows
identification of near contacts . Teeth must be marked where wax is
penetrating
Areas of heavy occlusal contacts

31. Dentures with well-balanced form function sufficiently well

32. At first , insert upper denture & observe the length of denture
border for proper extension . Frenum may be displaced while
making impression , so the frenal area must be checked

33. Labial frenum is displaced by notched border of the denture .
So, notch must be slightly deepened & widened vertically with
a large fissure bur. Also, bevel the inner margin of the notch

34. Border of lower denture is checked & adjusted . In mentalis
muscle & retromolar pad areas impression tends to be
overextended , so examination must be carefully performed

35. PIP is used as a thin layer painted on denture fitting surface
so that brush marks are visible

36. Denture is inserted & heavy pressure is applied with fingers.
Location of pressure spots in denture base that displace
soft tissue can be determined & eliminated .

37. An area where the paste is very thin or completely
displaced indicates pressure spots

38. Lower denture displays a pressure point on mylohyoid
ridge. This pressure spot is removed with a bur

39. This recording & trimming is repeated until denture base surface
do not show through the paste. The paste layer is even

40. PIP layer may be displaced due to brushing against the residual
ridge on insertion & removal of denture. It must be determined
as to whether areas with displaced paste are pressure areas or
due to accidental contact during insertion & removal

41. PIP must be wiped off with cotton using firm , uni-directional
stokes , not in a back & forth motion

42. Even paste record. No more adjustments are needed
Areas roughened during adjusting the basal surface must be smoothed with a
sandpaper cone & polished with silicone point

43. After adjusting the basal surface , occlusion refinement is done
at chair-side . Prior to occlusal adjustment , cotton rolls are
placed on both sides between upper & lower posterior teeth

44. Occlusal adjustment is always needed as inserting new dentures.
Occlusal contacts in CO must be checked using thin articulating paper
Heavy contacts in CO must be corrected by grinding the fossae &
cusp inclines

45. These procedures must be repeated until posterior teeth have
even occlusal contacts in CO

46. If interferences are found as the jaw is moved to right & left ,or
protruded , they must be eliminated ( like selective grinding on
articulator )

47. Occlusal registration paste
A separating medium is placed on upper teeth & relationship of
dentures recorded using occlusal registration paste .

48. An even layer of carborundum paste is placed on occlusal
surface of lower posterior teeth . Pt. is instructed to slowly move
the jaw to right & left and anteroposteriorly.

49. * Adjustment of the occlusion is necessary
1. to account for inherent errors caused
by processing changes
2. to eliminate errors apparent at the try-in
stage.

50. Causes of Occlusal Disharmony
1- Undetected errors in registering
jaw relations.
2- Errors in mounting the master casts
on the articulator.
3- Processing errors.
4. Dimensional changes of acrylic denture base
material

51. 5- Differences in tissue adaptation between the
processed denture bases & the record bases that
were used in recording maxillo- mandibular relations.
6- Changes in the supporting structures since the
impression is made ( as pt .using ill-fitting denture )

52. Correction of Occlusal Disharmony
* Selective Grinding
. To provide balanced contacts between the
teeth in the retruded jaw relationship,
. and in lateral & protrusive contact relations,
. and free sliding contact movements to
eccentric positions without cuspal
interferences.
. The occlusal vertical dimension must be
maintained.

55. Occlusal Discrepancies may be
corrected by either:1- Intra-oral Adjustment Techniques
a- Articulating paper
b- Occlusal indicator waxes
c- Central bearing devices
d- Abrasive paste.

56. 2- Extra-oral Adjustment Techniques
a- Laboratory Remounting
b- Clinical Remounting

57. Intra-oral Adjustment
Techniques
a- Articulating paper
* It will not give an accurate indication of
premature contacts because the resiliency
of the supporting tissues allows the
denture
to shift producing markings which are
frequently false.

58. Articulator paper detects premature occlusal contacts either
on articulator or in the pt’s mouth

59. Articulating paper of a different color must be used to
distinguish contacts marked in eccentric positions from those
marked in centric position

60. When selective grinding in lateral occlusions is completed ,
incisal pin usually stays in contact with incisal table during
lateral excursions

61. Marking & grinding procedure is repeated for both lateral
movements until markings indicate uniform contacts on working
& balancing sides

62. After completing selective grinding , marks made by movements
in all directions must show uniform contacts. Red marks show
contacts made in centric position & blue marks show contacts
made during lateral and protrusive movements

63. b- Occlusal Indicator Wax
* Two strips of adhesive green occlusal
indicator wax 6 mm. wide are placed
on the occlusal surfaces of the mandibular
denture.
The dentures are placed in the patient’ s
mouth & the patient’s is guided into
retruded contact position.

64. Wax must be carefully adapted
to occlusal surfaces of teeth
Mandible is gently guided so
that teeth make contact with the
lower jaw maximally retruded

65. c- Central- bearing Devices
* When a centralbearing
device
assembled,
bearing
is
the
pin
is
adjusted to permit
an evaluation of the
occlusion

66. D- Abrasive Paste
* Should not be used to eliminate errors
in occlusion of cusp teeth.
* The shifting of the denture bases as a
result of premature contact may result in
altering the occlusion so that centric
occlusion does not correspond to centric
relation.

67. Extra-oral Adjustment
Techniques
* Extra-oral adjustment of occlusion is
carried out by a procedure known
as
remounting & selective grinding.
It includes:1- Laboratory Remounting
2- Clinical Remounting

68. Laboratory Remounting
* Objectives:
1- Restore or re-establish the vertical
dimension of occlusion.
2- Perfect working and balancing occlusion
3- Establish protrusive balanced occlusion.

69. I- Restore the
Vertical
Dimension
of
Occlusion
(VDO)

70. Supporting or Centric Holding
Cusps
* The vertical
dimension of occlusion
is maintained by
occlusion of the palatal
cusps of the maxillary
teeth & the buccal
cusps of the mandibular
teeth.

71. Rules of adjustment
a- If the cusp is high in
centric & eccentric
positions. Reduce the
cusp.
b- If the cusp is high in
centric & not in eccentric
positions. Deepen the
opposing fossa or
marginal ridge.

72. * After all interceptive
contacts have been
eliminated in centric
& eccentric
positions:
a- Don’t reduce upper
palatal cusps or
lower buccal cusps
b- Don’t deepen the fossa
or marginal ridge of any
tooth

73. II- Occlusal Balance in Lateral
Excursions
* Rules of Adjustment
A- On the Working Side
Adjust the buccal cusps of the upper teeth & the
lingual cusps of the lower teeth ( B.U.L.L. rule ) to
eliminate deflective contacts.

75. B- On the Balancing side
Reduce inner inclines of lower buccal cusps , don’t reduce the
cusp tip as it is a centric holding cusp

76. III- Selective Grinding for Protrusive
Balance
* In protrusive balance, the anterior teeth
should make incisal edge contact at the
same time that the tips of the buccal &
lingual cusps of the posterior teeth contact.

77. Rules of Adjustment
a- If anterior teeth have heavy contact
with no posterior contact:
* Reduce the labio-incisal surfaces of the lower
teeth & the palatal surfaces of the upper
teeth.

78. b. If posterior teeth have heavy contact with no
anterior teeth contact. Reduce distal inclines of
upper cusps & mesial inclines of lower cusps

79. Clinical Remounting
* It consists of remounting the finished
denture on an articulator by using
interocclusal records in the patient’s
mouth
* The occlusion is then adjusted on the
articulator to remove discrepancies &
interferences.

80. Step by Step Procedure
I- Preserve the orientation of the Maxillary
cast to the Articulator:* A plaster remount index is an occlusal
registration of the maxillary denture which
is recorded on a remount jig attached to
the lower member of the articulator.

82. II- Preparation of the Remount
Casts
Casts should be constructed to facilitate
the positioning of the complete denture on
articulator & the process of occlusal
correction.

84. III- Centric Interocclusal Record
* The centric
interocclusal record
is used to mount the
mandibular denture
on the articulator as
a part of the clinical
remount & selective
grinding procedure.

85. Advantages of Clinical Remounting
1- It reduces patient participation.
2- It permits the dentist to see better what
he is doing.
3- It provides a stable working foundation;
denture bases are not shifting .

86. 4- The absence of saliva makes possible
more accurate markings with the
articulating paper.
5- Corrections can be made away from
the patient .