4. ACCORDING TO :
GPT-8
An artificial tooth on a fixed dental prosthesis that replaces a missing
natural tooth, restores its function, and usually fills the space
previously occupied by the clinical crown.
TYLMAN
the suspended member of a fixed partial denture which replaces the
lost natural tooth, restores function and occupies the space of the
missing tooth.
4
DEFINITION
.
The Glossary of Prosthodontic Terms. The Journal of Prosthetic Dentistry. 2005;94(1):10-92.
Tylman SMalone W. Tylman's Theory and practice of fixed prosthodontics. 8th ed.
81
6. PRETREATMENT ASSESSMENT
6
I] PONTIC SPACE:
One function of FPD is to prevent tilting or drifting of the
adjacent teeth into the edentulous space.
Drifting / tilting
Reduced pontic space
Difficulty in fabricating pontic
81
7. ESTHETIC ZONE
• Orthodontic alignment
• Abutment modification with
complete coverage retainers
NONESTHETIC ZONE
• Overly small pontics are
unacceptable
•Trap food
•Difficult to clean•Careful diagnostic waxing to
determine most appropriate
treatment
7
81
8. 2) RESIDUAL RIDGE CONTOUR
8
Features of Ideal Ridge
Contour:
Smooth and regular surface of
attached gingiva -Facilitate
maintenance of plaque-free
environment
Sufficient height and width
-Mimic adjacent tooth contours-
Appear to emerge from the
ridge
Facially, free of frenal
attachment
81
9. LOSS OF RESIDUAL RIDGE CONTOUR:
Unesthetic open gingival embrasures “BLACK
TRIANGLES”
Food impaction
Percolation of saliva during speech
9
81
10. 10
SIEBERT’S CLASSIFICATION OF RESIDUAL RIDGE DEFORMITIES :
Class I defects
Faciolingual loss of
tissue width with
normal ridge height.
Class II defects
Loss of ridge height
with normal ridge
width.
Class III defects
a combination of loss
in both dimensions.
81
11. 91% residual ridge deformities
↓
Anterior tooth loss
↓
Majority of patients with class II & class III defects
↓
Unsatisfied with esthetics
↓
Pre-prosthetic surgery
Ridge augmentation
11
81
12. SURGICAL MODIFICATION
12
Ridge augmentation with hard tissue grafts is not
indicated unless it is to receive an implant.
Class I Defects:
Infrequent
Not esthetically challenging
81
18. GINGIVALARCHITECTURE
PRESERVATION
18
By conditioning the extraction site and providing a matrix for healing,
the pre-extraction gingival architecture, or “socket,” can be preserved.
If bone levels are compromised :
Allograft materials
Hydroxyapatite
Tricalcium phosphate
Freeze dried bone
Can be grafted into the sockets
81
19. The tissue side of the pontic should be:
an ovate form - 2.5 mm apical to the
facial free gingival margin
The pontic causes tissue blanching as it
supports the papillae and facial/palatal
gingiva.
The tissue side of the pontic must
conform to within 1 mm of the
interproximal and facial bone contour to
act as a template for healing.
After approximately 1 month of healing,
oral hygiene access is improved by
recontouring the pontic to provide 1 to 1.5
mm of relief from the tissue. 19
81
20. Orthodontic Extrusions
Avoids ridge augmentation and gain vertical ridge height
However, Additional time and expense of orthodontic treatment,
as well as previous endodontic treatment is necessary
20
81
21. CLASSIFICATION
1. Depending on shape of surface
contacting the ridge(Tylman)
Sanitary
Modified sanitary
Spheroidal
Saddle
Ridge lap
Modified ridgelap
Ovate
2.According To Rosenstiel
Depending On Mucosal Contact
A. Mucosal contact
Ridge Lap
Modified Ridge Lap
Ovate
Conical
B. No Mucosal Contact
Sanitary(hygenic)
Modified Sanitary
3. Based on materials used
•Metal and porcelain veneered
•Metal and resin veneered
•All metal pontic
•All ceramic pontic
81
21
22. 4. METHOD OF FABRICATION:
•Custom made pontic
81
22
23. Pontic selection depends primarily on esthetics and oral hygiene.
ANTERIOR REGION
POSTERIOR REGIONS
23
PONTIC SELECTION
81
24. ANTERIOR PONTIC DESIGN – a
correctly placed anterior pontic should
have
1. All surfaces should be convex, smooth
and properly finished.
2. Contact with the labial mucosa should
be minimal (pin point) and pressure
free (lap facing).
3. The lingual contour should be in
harmony with adjacent teeth or pontics.
24
Pontic- residual ridge relationship: A research report.
Stein RS, J Prosthet Dent 1966; 16: 251
81
25. POSTERIOR PONTIC DESIGN – a correctly designed pontic
should have
1. All surfaces should be convex, smooth and properly finished.
2. Contact with the buccal contiguous slopes should be minimal (pin
point) and pressure free (modified ridge lap).
3. Occlusal table must be in functional harmony with the occlusion
of all of the teeth
4. Buccal and lingual shunting mechanism should conform to those
of the adjacent teeth.
5. The overall length of buccal surface should be equal to that of the
adjacent abutments or pontics.
25
Pontic- residual ridge relationship: A research report. Stein RS, J Prosthet Dent 1966; 16: 251
81
26. PRE-FABRICATED PONTIC FACINGS
These are commercially available porcelain pontics which can be
altered by the dentist and reglazed if necessary. These include:
a) Trupontic – A horizontal tubular slot in the
center of the lingual surface of the facing.
b) Interchangeable facings/flat back facing–
Manufactured with vertical slot running down
the flat lingual surface, this facing is retained
with a lug which engages the retention slot.81
26
27. c) Sanitary facing –flat occlusal
surface and a slot on the proximal
surface to fit into the metal
projections made in the FDP
d) Pin facing – A flat lingual facing
with two horizontal pins for
retention.
81
27
28. e) Modified Pin Facing
Facing is modified by adding porcelain
to lingual gingival area of a pin facing
f)Reverse pin facing – Porcelain
denture teeth can be modified to be
used as the bridge facing. Porcelain is
added to the gingival end of the facing
and multiple precision pin holes are
drilled into the lingual surface
81
28
29. g. Harmony facing –
This facing is supplied with an
uncontoured porcelain gingival
surface and usually two retentive
pins on the flat lingual side.
h. Porcelain fused to metal facing
Facing consists of a metal core over
which porcelain is fused.
i. Pontips:
Convex gingival surface having
pinpoint tissue contact and attached
to the backing occlusally with
retentive pins.
81
29
30. SANITARY OR HYGIENIC PONTIC
Zero tissue contact
Occlusalgingival thickness should be atleast 3mm
Convex mesiodistally and faciolingually
Space beneath the pontic – 2mm ( Rosenstiel)
- 3 mm ( Tylman)
Adequate space for cleaning
Modified sanitary pontic:- gingival portion
is shaped like a concave archway mesiodistally
between the retainers and convex faciolingually.
Allows increased connector size while
decreasing the stress concentrated in the pontic
and connectors.
Recommended for mandibular posteriors
FISH BELLY
ARC-FIXED OR PEREL
81
30
32. SADDLE PONTIC OR RIDGE LAP PONTIC
The saddle pontic has a concave fitting surface that overlaps the
residual ridge buccolingually, simulating the contours and emergence
profile of the missing tooth on both sides of the residual ridge.
81
32
33. Saddle or ridge lap designs should be avoided
The concave gingival surface of the pontic is not accessible to cleaning
with dental floss>>>>plaque accumulation>>>>> tissue inflammation.
33
81
34. The modified ridge lap pontic combines the best features of the hygienic
and saddle pontic designs, combining esthetics with easy cleaning.
34
MODIFIED RIDGE LAP PONTIC
• Overlaps the residual ridge on
the facial (to achieve the
appearance of a tooth emerging
from the gingiva)
• Remains clear of the ridge on the
lingual side.
81
35. Tissue contact should resemble a letter T whose vertical arm ends at the
crest of the ridge.
The ridge contact should be upto the midline of the edentulous ridge.
Most common pontic form used in areas of high visibility---
maxillary and mandibular anterior teeth and maxillary premolars and
first molars
35
81
36. CONICAL PONTIC
• egg-shaped, bullet-shaped, or
heart-shaped
• Convex with only one point of
contact at the center of the
residual ridge.
• recommended for the
replacement of mandibular
posterior teeth where esthetics is
a lesser concern.
81
36
37. The facial and lingual contours are dependent on the width of the
residual ridge;
a knife-edged residual ridge necessitates flatter contours with a
narrow tissue contact area.
This type of design may be unsuitable for broad residual ridges,
because the emergence profile associated with the small tissue
contact point may create areas of food entrapment
37
81
38. most esthetically appealing
Its convex tissue surface resides
in a soft tissue depression or
hollow in the residual ridge,
which makes it appear that a tooth
is literally emerging from the
gingiva
38
OVATE PONTIC
81
39. Socket-preservation techniques
should be performed at the time
of extraction to create the tissue
recess from which the ovate
pontic form will emerge.
For a preexisting residual ridge,
soft tissue surgical
augmentation is typically
required. When an adequate
volume of ridge tissue is
established, a socket depression
is sculpted into the ridge with
surgical diamonds or
electrosurgery. 39
81
41. 41
Rosenstiel S F et al : Contemporary Fixed Prosthodontics, 4th
edn
81
42. 42
Aesthetic replacement of an anterior tooth using the natural tooth
as a pontic; an innovative technique
Purra A Mushtaq M.. The Saudi Dental Journal. 2013;25(3):125-128.
81
43. The biologic principles of pontic design pertain to the maintenance
and preservation of the residual ridge, abutment and opposing teeth,
and supporting tissue.
Factors of specific influence are,
43
BIOLOGIC CONSIDERATIONS
81
44. Pressure free contact between the pontic and the underlying tissue is
indicated to prevented ulceration and inflammation of the soft tissues.
When a pontic rests on mucosa, some ulcerations may appear as a result
of the normal movement of the mucosa in contact with the pontic.
Positive ridge pressure (hyperpressure) may be caused by excessive
scraping of the ridge area on the definitive cast
44
RIDGE CONTACT
81
45. Pontic- residual ridge relationship: A research report.
Stein RS, J Prosthet Dent 1966; 16: 251
- To determine the frequency and the nature of tissue reaction of
underlying the residual ridge mucosa to specific pontic designs and
various materials used in pontic constructions.
- Upon removal of pontics, inflammatory reactions of the underlying
mucosa were found under 95 per cent of the pontics.
The ideal design was shown to be a “modified ridge lap” in the
posterior region and a “lap facing” in the anterior region, with a
pinpoint contact on the facial contiguous slope of the residual ridge.
The ideal design should include surface smoothness and a fine finish
A successful artificial tooth replacement was characterized by a
healthy tissue response with the appearance of a lack of contact
between the residual ridge and undersurface of the pontic. 45
81
46. Cavozos E : Tissue response to fixed partial denture pontics.
J Prosthet Dent 1968; 20: 143
46
A study to demonstrate that the
adaptations of pontic to the ridge or the
amount of “relief” on the cast is highly
significant and directly proportional to
the amount of unfavourable tissue
change.
Absolute minimal (0.0 to 0.25mm of
cast scraping) produced no tissue
changes.
When the cast scraping was increased to
1mm, tissue changes were produced
varying from mild inflammation to
acute ulceration81
47. Ridge irritation microbial plaque between the gingival surface
of the pontic and the residual ridge
tissue inflammation and calculus formation.
47
ORAL HYGIENE CONSIDERATIONS
Normally, where tissue contact
occurs, the gingival surface of a
pontic is inaccessible to the bristles
of a tooth brush. Therefore, excellent
hygiene habits must be developed by
the patient.
81
48. 48
Devices such as proxy brushes, pipe
cleaners, Oral-B Super Floss, and
dental floss with a threader are highly
recommended
Gingival embrasures around the pontic
should be wide enough to permit oral
hygiene aids.
81
49. Should provide good esthetic results, biocompatibility, rigidity, and
strength to withstand occlusal forces; and longevity.
Occlusal contacts should not fall on the junction between metal and
porcelain during centric or eccentric tooth contacts, nor should a metal
ceramic junction occur in contact with the residual ridge on the gingival
surface of the pontic.
Investigations into the biocompatibility of materials used to
fabricate pontics have centered on two factors :
1. The effect of the materials and
2. The effects of surface adherence.
49
PONTIC MATERIAL
81
50. Well-polished gold is smoother, less prone
to corrosion, and less retentive of plaque
than an unpolished or porous casting.
For easier plaque removal and
biocompatibility, the tissue surface of the
pontic should be made in glazed porcelain
However, ceramic tissue contact may be
contraindicated in edentulous areas where
there is minimal distance between the
residual ridge and the occlusal table.
50
81
51. HENRY P J ET AL: TISSUE CHANGES BENEATH FIXED
PARTIAL DENTURES. J PROSTHET DENT 1966; 16: 937
placed 14 pontics on human gingival tissue.
gingival response to polished gold, Glazed porcelain or unglazed
porcelain
there were general histologic changes in the tissue under all the
materials tested.
noted that glazed porcelain was the most hygienic material used and it
is superior in terms of esthetics and ease of cleaning.
51
81
52. Reducing the buccolingual width of the pontic by as much as 30%
12% increase in chewing efficiency can be expected from a one
third reduction of pontic width.
Narrowing the occlusal table may actually impede the development
of a harmonious and stable occlusal relationship
Difficulties in plaque control and improper cheek support.
Pontics with normal occlusal widths (at least on the occlusal third)
are generally recommended.
One exception is if the residual alveolar ridge has collapsed
buccolingually. Reducing pontic width may then be desired,
thereby lessening the lingual contour and facilitating plaque control
measures. 52
OCCLUSAL FORCES
81
53. Mechanical problems may be caused by
improper choice of materials
poor frame work design
poor tooth preparation
poor occlusion.
Therefore, evaluating the likely
forces on a pontic and designing
accordingly are important. For
example, a strong all metal pontic
may be needed in high stress
situations rather than a metal ceramic
pontic which would be more
susceptible to fracture. 53
MECHANICAL CONSIDERATIONS
81
54. A well fabricated metal ceramic ponti
is strong, easy to keep clean, and
looks natural.
54
METAL CERAMIC PONTICS
The framework must provide a
uniform veneer of porcelain
(approximately 1.2 mm).
The metal surfaces to be veneered
must be smooth and free of pits
Sharp angles on the veneering area
should be rounded.
Occlusal centric contacts must be
placed at least 1.5 mm away from
the metal-porcelain junction
81
55. Resistance to abrasion is lower than enamel or porcelain,
no chemical bond existed between the resin and the metal framework,
55
RESIN-VENEERED PONTICS
• Continuous dimensional change of the
veneers often caused leakage at the
metal-resin interface, with subsequent
discoloration of the restoration.
• New-generation indirect resins-
High flexural strength, minimal
polymerization shrinkage, and wear
rates comparable with those of tooth
enamel
81
56. Composite resins can be used in fixed partial dentures without a
metal substructure.
A substructure matrix of impregnated glass or polymer fiber
provides structural strength.
Excellent marginal adaptation and esthetics
56
FIBER-REINFORCED COMPOSITE RESIN
PONTICS
81
58. No matter how well biologic and mechanical principles have been
followed during fabrication, the patient will evaluate the result by
how it looks, especially when anterior teeth have been replaced.
58
ESTHETIC CONSIDERATIONS
81
59. An esthetically successful pontic will replicate the form, contours,
incisal edge, gingival and incisal embrasures, and color of adjacent
teeth.
The pontic’s simulation of a natural tooth is most often betrayed at
the tissue pontic interface.
Special attention should be paid to the contour of the labial surface
as it approaches the pontic-tissue junction to achieve a “natural”
appearance.
59
THE GINGIVAL INTERFACE
81
60. This cannot be accomplished by
merely duplicating the facial
contour of the missing tooth.
If the original tooth contour were
followed, the pontic would look
unnaturally long incisogingivally.
60
81
61. Special care must be taken when
studying where shadows fall around
natural teeth, particularly around
the gingival margin.
If a pontic is poorly adapted to the
residual ridge, there will be an
unnatural shadow in the cervical
area >> spoils the illusion of a
natural tooth.
Recesses occurring at the gingival
interface collect food debris, further
betraying the illusion of a natural
tooth.
61
81
62. The modified ridge-lap pontic is
recommended for most anterior
situations; it compensates for lost
buccolingual width in the residual
ridge by overlapping what remains
However, When appearance is of
utmost concern, the ovate pontic,
used in conjunction with alveolar
preservation or soft tissue ridge
augmentation
62
81
63. Ridge resorption will make a pontic look
too long in the cervical region.
An abnormal labiolingual position or
cervical contour, however, is not
immediately obvious.
This fact can be used to produce a pontic of
good appearance by recontouring the
gingival half of the labial surface.
63
INCISOGINGIVAL LENGTH
81
64. In areas where tooth loss is
accompanied by excessive loss
of alveolar bone, the pontic is
shaped to simulate a normal
crown and root with emphasis
on the cementoenamel
junction.
The root can be stained to
simulate exposed dentin
64
81
65. If augmentative measures are
contraindicated or undesirable,
small alveolar deficiencies and
missing papillae can be
reconstructed by restorative
measures.
The exact shade of the gingiva
has to be established with
special gingival shade guides.
The basal surface must
demonstrate a convex shape
similar to the ovate pontic
designs for the dental floss to
establish tight contact with
all the surface areas. 65
GINGIVA-COLORED CERAMICS
Daniel E , H Spiekermann: A review of esthetic pontic design options. Quintessence Int
2002;33:736-746
81
66. Separately fabricated ceramic gingival masks can be used to make
subsequent adjustments in permanently placed restorations.
This method is particularly suitable for patients with a local alveolar
ridge defect that has not been corrected by augmentation of the soft
tissue.
66
ALL-CERAMIC GINGIVAL MASKS
Daniel E , H Spiekermann: A review of esthetic pontic design options. Quintessence Int
2002;33:736-746
81
67. Frequently, the space available for a
pontic will be greater or smaller
than the width of the contra lateral
tooth.
If possible, such a discrepancy
should be corrected by orthodontic
treatment.
If this is not possible, an acceptable
appearance may be obtained by
incorporating visual perception
principles into the pontic design.
67
MESIODISTAL WIDTH
81
68. The features of the contra lateral
tooth should be duplicated as
precisely as possible in the pontic,
and the space discrepancy can be
compensated by altering the shape
of the proximal areas.
The retainers and the pontic can
be proportioned to minimize the
discrepancy. (This is another
situations in which a diagnostic
waxing procedure will help solve a
challenging restorative problem).
68
81
69. Space discrepancy presents less of a
problem when posterior teeth are
being replaced because their distal
halves are not normally visible from
the front.
Discrepancy here can be managed
by duplicating the visible mesial
half of the tooth and adjusting the
size of the distal half.
69
81
73. 73
PURPOSE: To evaluate the load-bearing capacities of fiber-
reinforced composite (FRC) fixed dental prostheses (FDP) with
pontics of various materials and thicknesses.
MATERIALS: 72 FDPs with frameworks made of continuous
unidirectional glass fibers (everStick C&B) were fabricated.
Three different pontic materials were used: glass ceramics, polymer
denture teeth, and composite resin.
The FDPs were divided into 3 categories based on the occlusal
thicknesses of the pontics (2.5 mm, 3.2 mm, and 4.0 mm).
Fiber-reinforced Composite Fixed Dental
Prostheses
with Various PonticsThe Journal of Adhesive Dentistry2014Vol 16, No 2
81
74. 74
CONCLUSION:
•By increasing the occlusal
thickness of the pontic, the load-
bearing capacity of the FRC FDPs
may be increased.
•The highest load-bearing capacity
was obtained with 4.0 mm
thickness in the ceramic pontic.
•However, with thinner pontics,
polymer denture teeth and
composite pontics resulted in
higher load-bearing values
81
75. 75
Enhancing Esthetics with a Fixed Prosthesis Utilizing an
Innovative Pontic Design and Periodontal Plastic Surgery
This article addresses how to reestablish or maintain papilla height
and the facial gingival tissue between a single or multiple missing
teeth adjacent to a natural tooth or an implant by using a pontic
design termed the E-pontic
Limitations: when there is an alveolar ridge defect with apico-coronal
loss of tissue and/or a combination of buccolingual and apico-coronal
loss of tissue
At least 2 mm of soft tissue
over the alveolar bone is
necessary to create the site;
3–5 mm of soft tissue
coverage is ideal.
Journal of Esthetic and Restorative Dentistry, 2014
81
77. 77
PREFABRICATED WAX PONTICS
Advantages:
* Without collar
* Reduced occlusal depths
* Reinforced approximal surfaces
* Perfect scraping and modelling
characteristics
Primary use: Temporary
Bridges
Plastic to fabricate quick and
economical temporary
bridges.
•Wear-resistant, vacuum-
processed synthetic resin
•Special lingual channel
ensures pontic locks into the
plastic
81
78. The pontic design is said to determine the success or failure of a
bridge.
Designs that allow easy plaque control are especially important to a
pontic’s long term success.
Minimizing tissue contact by maximizing the convexity of the
pontic’s gingival surface is essential.
Special consideration is also needed to create a design that
combines easy maintenance with natural appearance and adequate
mechanical strength.
78
CONCLUSION
The dentist should not attempt to duplicate nature
exactly, but should attempt to support it by supplying a
prosthesis based on sound biomechanical principles.81
79. 1. Rosenstiel S F et al : Contemporary Fixed Prosthodontics, 4th
edn Missouri, Mosby Inc, pg 513
2. Shillingburg H T et al : Fundamentals of fixed
prosthodontics, ed 4, Chicago , Quintessence
Publishing, pg 485
3. Tylman SMalone W. Tylman's Theory and practice of fixed
prosthodontics. 8th ed.
4. The Glossary of Prosthodontic Terms. The Journal of
Prosthetic Dentistry. 2005;94(1):10-92.
5. Cavozos E : Tissue response to fixed partial denture pontics.
J Prosthet Dent 1968; 20: 143
6. Daniel Edelhoff, H Spiekermann: A review of esthetic
pontic design options. Quintessence Int 2002;33:736-746
7. Henry P J et al: Tissue changes beneath fixed partial
dentures. J Prosthet Dent 1966; 16: 937
79
REFERENCES
81
80. 7. Perel M L : A modified sanitary pontic. J Prosthet Dent 1972; 28:
587
8. Stein RS: Pontic- residual ridge relationship: A research report. J
Prosthet Dent 1966; 16: 251
9. Korman R. Enhancing Esthetics with a Fixed Prosthesis Utilizing
an Innovative Pontic Design and Periodontal Plastic Surgery.
Journal of Esthetic and Restorative Dentistry. 2014;27(1):13-28.
10. Fiber-reinforced Composite Fixed Dental Prostheses with Various
Pontics The Journal of Adhesive Dentistry2014Vol 16, No 2
11. Kim T, Cascione D, Knezevic A. Simulated tissue using a unique
pontic design: A clinical report. The Journal of Prosthetic Dentistry.
2009;102(4):205-210.
12. Purra AMushtaq M. Aesthetic replacement of an anterior tooth
using the natural tooth as a pontic; an innovative technique. The
Saudi Dental Journal. 2013;25(3):125-128. 80
81
The restorations of edentulous areas with fixed partial dentures (FPDs) present a particular challenge for the clinician. Because of their ease of use and favorable long term results, conventional FPDs represent the most popular treatment measure today. In these restorations, the pontic must fulfill the complex roles of replacing the function of the lost tooth, achieving an
In addition the pontic must meet certain structural requirements to ensure the mechanical stability of the restorations.
When orthodontic repositioning is not possible, increasing the proximal contours of adjacent teeth may be better than making an FDP with undersized pontics
If there is no functional or esthetic deficit, the space can be maintained without prosthodontic intervention.
soft tissue from the lingual side of the edentulous site is used. The epithelium is removed, and the tissue is thinned and rolled back upon itself, thereby thickening the facial aspect of the residual ridge
Pouches may also be prepared in the facial aspect of the residual ridge into which subepithelial or submucosal grafts harvested from
the palate or tuberosity may be inserted
a wedge-shaped connective tissue graft is inserted into a pouch preparation on the facial aspect of the residual ridge. The epithelial portion of the wedge may be positioned coronally to the surrounding epithelium if an increase of ridge height is desired
Useful for treating Class III ridge defects. It is a thick “free gingival graft” harvested from partial or full-thickness palatal donor sites.
Class 3 ridge defect. Donor site. Graft sutured in place.. Augmented ridge
Preservation of the alveolar process can be achieved through immediate restorative and periodontal intervention at the time of tooth removal. Because socket preservation is dependent on underlying bone contour, the extraction of the tooth to be replaced should be atraumatic and aimed at preserving the facial plate of bone. The scalloped architecture of interproximal bone forming the extraction site is essential for proper papilla form, as are facial bone levels in the prevention
of alveolar collapse.
Immediately after preparation of the extraction site, a carefully shaped interim FDP is placed
Pontic selection depends primarily on esthetics and oral hygiene. In the anterior region, where esthetics is a concern, the pontic should be well adapted to the tissue to make it appear that it emerges from the gingiva.
Conversely, in the posterior regions (mandibular premolar and molar areas), esthetics can be compromised in the interest of designs that are more amenable to oral hygiene
Hyperbolic paraboloid
Morton L Perel in 1972 described a modified sanitary pontic which has a free archway design and is concave mesiodistally. Proximally the solder joints of the pontic are elongated. This addition increases the strength of what is considered to be the weakest part of any posterior fixed prosthesis.
It is called ridge lap because it overlaps the facial lingual aspects of the ridge.
There could be a faciolingual concavity on the facial side of the ridge, cleaned and well tolerated as long as the tissue contact is narrow M-D and F-L
To enable optimal plaque control, the gingival surface must have no depression or hollow. Rather, it should be as convex as possible from mesial to distal (the greater the convexity, the easier the oral hygiene)
easy for the patient to keep clean.
a knife-edged residual ridge will necessitate flatter contours with a narrow tissue contact area. This type of design may be unsuitable for
broad residual ridges, because the emergence profile associated with the small tissue contact point may create areas of food entrapment The sanitary or hygienic pontic is the design of choice in these clinical situations.
before 1930 the root tipped pontic.
Careful treatment planning is necessary for successful results
The ovate pontic’s advantages include it’s pleasing appearance and it’s strength, when used successfully with ridge augmentation, it’s emergence from the ridge appears identical to that of a natural tooth. This type of pontic design, however, requires an adequate amount of soft tissue, which has to be sculpted accordingly.13 Various techniques are available for this purpose, ranging from controlled regeneration directly after the extraction of the tooth (immediate pontic technique) to plastic surgery (gingival grafting), which is accompanied by tissue conditioning in the course of the subsequent prosthodontic treatment.
its recessed form is not susceptible to food impaction.
The broad convex geometry is stronger than that of the modified ridge lap pontic
Because the tissue surface of the pontic is convex in all dimensions, it is accessible to dental floss
The apical opening of the pulp canal was cleaned, enlarged slightly, and sealed with composite resin. A modified ridge-lap pontic was designed-The pontic was stabilized in the extraction socket with a resin-wire splint as a provisional restoration. After 1 month recall the tooth was stablised on the cast. A
retention lock was also prepared on the palatal aspect of the natural tooth pontic (4-mm high, 3.5-mm wide, and 2- mm deep;
the pressure area should be identified with a disclosing medium (i.e, pressure indicating paste) and the pontic recontoured until tissue contact is entirely passive.
This passive contact should occur exclusively on keratinized attached tissue.
Unlike removable partial dentures, FPDs cannot be taken out of the mouth for daily cleaning. Patients must be taught efficient oral hygiene techniques, with particular emphasis on cleaning the gingival surface of the pontic. The shape of the gingival surface, its relation to the ridge, and the materials used in its fabrication will influence ultimate success.
Unlike removable partial dentures, FPDs cannot be taken out of the mouth for daily cleaning. Patients must be taught efficient oral hygiene techniques, with particular emphasis on cleaning the gingival surface of the pontic.
abricate the pontic should provide good esthetic results where needed; biocompatibility, rigidity, and strength to withstand occlusal forces; and longevity.
FPDs should be made as rigid as possible, because any flexure during mastication or parafunction may cause pressure on the gingiva and cause fractures of the veneering material.
Occlusal contacts should not fall on the junction between metal and porcelain during centric or eccentric tooth contracts, nor should a metal ceramic junction occur in contact with the residual ridge on the gingival surface of the pontic.
Placing ceramic on the tissue side of the pontic may weaken the design of the metal substructure, particularly with porcelain occlusal surface
Reducing the buccolingual width of the pontic by as much as 30% has been suggested as a way to lessen occlusal forces on, abutment teeth.
forces are lessened only when chewing food of uniform consistency and that a mere 12% increase in chewing efficiency can be expected from a one third reduction of pontic width.
In fact, narrowing the occlusal table may actually impede or even preclude development of a harmonious and stable occlusal relationship. Like a malposed tooth, it may cause difficulties in plaque control and may not provide proper cheek support. For these reasons, pontics with normal occlusal widths (at least on the occlusal third) are generally recommended. One exception is if the residual alveolar ridge has collapsed buccolingually. Reducing pontic width may then be desired, thereby lessening the lingual contour and facilitating plaque control measures.
Potentially harmful forces are more likely to be encountered if an FPD is loaded by the accidental bitting on a hard object or by parafunctional activities like bruxism rather than by chewing foods of uniform consistency. These forces are not reduced by narrowing the occlusal table.
These factors can lead to fracture of the prosthesis or displacement of the retainers.
Long span posterior FPDs are particularly susceptible to mechanical problems.
significant flexing from high occlusal forces and because The deflection of a fixed dental prosthesis is proportional to the cube of the length of its span
However, mechanical failure can occur and often is attributable to inadequate frame work design.
A reliable technique for ensuring uniform thickness of porcelain is to wax the fixed prosthesis to complete anatomic contour and then accurately cut back the wax to a predetermined depth
The metal surfaces to be veneered must be smooth and free of pits. Surface irregularities will cause incomplete wetting by the porcelain slurry, leading to voids at the porcelain metal interface the reduce bond strength and increase the possibility of mechanical failure . Sharp angles on the veneering area should be rounded. They produce increased stress concentrations that can cause mechanical failure.
Their resistance to abrasion was lower then enamel or porcelain, and noticeable wear occurred with normal tooth-brushing.
Furthermore, the relatively high surface area/volume ratio of a thin resin veneer made dimensional change from water absorption and thermal fluctuations (thermo cycling) a problem.
Because no chemical bond existed between the resin and the metal framework, the resin was retained by mechanical means (eg., undercuts). They are easy to manipulate and repair and do not require the high–melting range alloys needed for metal ceramic techniques.
The physical properties of this system, combined with its excellent marginal adaptation and esthetics, make it a possible metal free alternative for FPDs, although long term clinical performance is not yet known.
Many esthetic considerations that pertain to single crowns also apply to the pontic. Several problems unique to the pontic may be encountered when attempting to achieve a natural appearance.
The greatest challenge here is to compensate for anatomic changes that occur after extraction.
To achieve the illusion of a natural tooth, an esthetic pontic must deceive observers into believing they are seeing a natural tooth.
in normal situations, light falls from above and an object’s shadow is below it. Unexpected lighting or unexpectedly placed shadows can be confusing to the brain. Because of past experience, the brain “knows” that a tooth grows out of the gingiva, and it therefore “sees” a pontic as a tooth unless telltale shadows suggest otherwise.
Obtaining a correctly sized pontic simply by duplicating the original tooth is not possible. The height of a tooth is immediately obvious when the patient smiles and shows the gingival margins. This fact can be used to produce a pontic of good appearance by recontouring the gingival half of the labial surface. The observer sees a normal tooth length but is unaware of the abnormal labial contour. The illusion is successful.
However, such pontics then have considerably increased tissue contact and require scrupulous plaque control for long term success. Ridge augmentation procedures have been successful in correcting areas of limited resorption. When bone loss is severe, the esthetic result obtained with an RPD is often better than with an FPD.
If augmentative measures are contraindicated or undesirable, small alveolar deficiencies and missing papillae can be reconstructed by restorative measures. First, the exact shade of the gingiva has to be established. This can be accomplished with special gingival shade guides that are supplied with the different commercially available pink veneering materials. The basal surface must demonstrate a convex shape similar to the ovate pontic designs for the dental floss to establish tight contact with all the surface areas.
an impression is taken of the labial surface of tbe restoration using a customized tray and a medium-viscosity polyether materialThe masks are bonded to the existing restoration with a light-curing, low-viscosity resin composite, This solution, however, increases
the risk of plaque accumulation. Because the material ages quickly, the prosthesis has to be replaced on a regular basis
In the same way that the brain can be confused into misinterpreting the relative sizes of shapes or lines because of an erroneous interpretation of perspective, a pontic of abnormal size may be designed to give the illusion of being more natural size.
This is usually due to uncontrolled tooth movement that occurred when a tooth was removed and not replaced.
The width of an anterior tooth is usually identified by the relative positions of the mesiofacial and distofacial line angles, and the over all shape by the detailed pattern of surface contour and light reflection between these line angels.
A 52-year-old woman. The areas of the pencil marks represented the region where the patient would have the deepest point of tissue adaptation and was scored to a depth of 1 mm and trim the alveolar crest to 0.5 mm. the pontic was convex in the buccal and lingual regions and concave in the middle of the pontic
Slowly screwing prosthesis into place for 15 minutes allows tissue to contour after complete seating.
1 week, 2 weeks, 1 month, 3, 6, and 10 months to evaluate the the tissue beneath the pontic. An oral hygiene evaluation,
especially of the tissue under the pontics, was performed at each visit.
The provisional implant fixed partial denture was worn for 10 months before the definitive prosthesis was inserted.
Compression of the pontic site in the mid-lingual portion, along with deeper sculpting depth at the facial gingival margin and interproximal line angles, is enough to ensure complete seating of the pontic and abutment crowns
The pontic design is said to determine the success or failure of a bridge. Designs that allow easy plaque control are especially important to a pontic’s long term success. Minimizing tissue contact by maximizing the convexity of the pontic’s gingival surface is essential. Special consideration is also needed to create a design that combines easy maintenance with natural appearance and adequate mechanical strength.
Based on classic clinical studies, a number of authors have advocated the use of modified ridge lap pontics with a well polished and smooth, convex surface that results in pressure free or mild contact with the alveolar ridge over a very small area for a better preservation of the soft tissue health. However, the modified ridge lap pontic design has certain limitations, depending on the pattern of alveolar ridge resorption, and cannot always be used without compromising esthetics and functions.
Because the aforementioned factors are decisive in restoring anterior teeth, new alternatives in pontic design were developed, giving the illusion that the replaced tooth emerges from the gingiva like a natural tooth. This ovate pontic design requires the preparation of a suitable recipient site, which can be achieved by the application of modern ridge preservation techniques, including an atraumatic extraction and the direct support of the extraction socket by the use of the immediate pontic technique.
Metal ceramic pontic fabrication is straightforward and practical. However, it requires careful execution for maximum strength, appearance, and effective plaque control. Alternatively procedures may some times be helpful, particularly when gold alloys are used for the retainers. Resin veneered pontics should be restricted to use as longer term provisional restorations, and all metal pontics may be the restoration of choice in non-esthetics situations, particularly where forces are high.
Thus the design of the pontic is probably the most important factor in determining the success of the restoration of the patient. If the patient is unable to clean effectively and maintain the pontic the restoration will be unsuccessful.