Pontics 1

Pontic Design
11/26/2019 Sherif Sultan, BDS, MsC, PhD Fixed prosthodontics 1

Definition
• Pontics are the artificial
teeth of a partial fixed
dental prosthesis (FDP)
that replace missing
natural teeth, restoring
function and
appearance. They must
enable continued oral
health and comfort.
11/26/2019
Sherif Sultan, BDS, MsC, PhD Fixed
prosthodontics
2

PRETREATMENT ASSESSMENT
• In the treatment-planning phase, diagnostic
casts and waxing procedures are necessary
for determining optimal pontic design.
• Pontic Space
• Residual Ridge Contour
• Gingival Architecture Preservation
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Pontic Space
• One function of an FDP is to prevent tilting or drifting
of the adjacent teeth into the edentulous space. If such
movement has already occurred, the space available
for the pontic may be reduced and its fabrication
complicated. In such circumstances, creating an
acceptable appearance without orthodontic
repositioning of the abutment teeth is often
impossible, particularly if esthetic appearance is
important. (Modification of abutments with complete-
coverage retainers is sometimes feasible.) Careful
diagnostic waxing procedures help determine the most
appropriate treatment
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Residual Ridge Contour
• The edentulous ridge’s should be carefully evaluated
during the treatment-planning phase. An ideally
shaped ridge has
• a smooth, regular surface of attached gingiva, which
facilitates maintenance of a plaque-free environment.
• Its height and width should allow placement of a
pontic that appears to emerge from the ridge and
mimics the appearance of the neighboring teeth.
• Facially, it must be free of frenum attachment and be
of adequate height for normal appearance of
interdental papillae.
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 Loss of residual ridge
contour may lead to
unesthetic open
gingival embrasures
(“black triangles),
food impaction ,
 and percolation of
saliva during speech.
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Siebert classified residual ridge
deformities into three categories
• Class I defects: loss of ridge width with normal
ridge height
• Class II defects: loss of ridge height with
normal ridge width
• Class III defects: loss of both ridge height and
width.
N.B class 0 : normal ridge height and width.
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Preprosthetic surgery to augment such residual ridge defects
• Class I Defects
• Class I defects are infrequent and are not
esthetically challenging, surgical
augmentation of ridge width is uncommon.
• By paying careful attention to interim pontic
contour, the operator can identify patients
who would benefit from surgery.
• the roll technique and the pouch technique.
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the pouch technique
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Class II and Class III Defects
 interpositional graft
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• An onlay graft(It is a thick “free gingival graft”
harvested
• from partial- or full-thickness palatal donor
sites.
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Gingival Architecture
Preservation(socket preservation)
• Resorption of the alveolar ridge after tooth
extraction occurs primarily at the buccal plate,
typically resulting in a horizontal defect. Bone
loss averages 3 to 5 mm at 6 months after
extraction; 50% of the width of the alveolar
ridge is lost at 12 months
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PONTIC CLASSIFICATION(pontic
ridge relation, depends on esthetic
and hygiene)
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Saddle or Ridge-Lap Pontics
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Saddle or Ridge-Lap Pontics
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Modified Ridge-Lap Pontic
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Ovate Pontic
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Ovate Pontic
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Conical Pontic
egg-shaped, bullet-shaped, or heart-
shaped
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Sanitary or Hygienic Pontic
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BIOLOGIC CONSIDERATIONS
1. Ridge Contact
• There should be Pressure-free contact between
the pontic and the underlying tissues to prevents
ulceration and inflammation of the soft tissues.
• If any blanching of the soft tissues is observed at
evaluation, the pressure area should be identified
with a disclosing medium (e.g., pressure-
indicating paste), and the pontic should be
recontoured until tissue contact is entirely
passive.
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2. Oral Hygiene Considerations
• The chief cause of ridge irritation is the toxins released from
microbial plaque, which accumulate between the gingival surface
of the pontic and the residual ridge, causing tissue inflammation
and calculus formation.
• Therefore, the patient must develop excellent hygiene habits.
Devices such as proxy brushes, pipe cleaners, Oral-B Super Floss
(Oral-B, Procter & Gamble), and dental floss with a threader are
highly recommended
• an accurate description of pontic design should be submitted to
the laboratory, and the prosthesis should be checked and
corrected if necessary before cementation

3. Pontic Material
• Any material chosen to fabricate the pontic should
provide good esthetic results where needed;
biocompatibility, rigidity, and strength to withstand
occlusal forces; and longevity.
• FDPs 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 contacts, nor should a metalceramic
junction be in contact with the residual ridge on the
gingival surface of the pontic.
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 Glazed porcelain is generally considered the most
biocompatible of the available pontic materials
 For easier plaque removal and biocompatibility, the
tissue surface of the pontic should be made in glazed
porcelain except if there is no enough occlusogingival
space especially if occulsal porcelain is required.(in this
case it is done in metal)
 Glazed porcelain looks very smooth, but when viewed
under a microscope, its surface shows many voids and is
rougher than that of either polished gold or acrylic resin
 Regardless of the choice of pontic material, patients
can prevent inflammation around the pontic with
meticulous oral hygiene
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3. Occlusal Forces
• Reducing the buccolingual width of the pontic
by as much as 30% has been suggested as a
way to lessen occlusal forces on, and thus the
loading of, abutment teeth.
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MECHANICAL CONSIDERATIONS
• The prognosis of FDP pontics is compromised if
mechanical principles are not followed closely.
• Mechanical problems may be caused by improper
choice of materials, poor framework design, poor
tooth preparation, or poor occlusion. These
factors can lead to fracture of the prosthesis or
displacement of the retainers.
• Long-span posterior FDPs are particularly
susceptible to mechanical problems.
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Available Pontic Materials
• 1. Metal-Ceramic Pontics
• Most pontics are fabricated by the metal-ceramic
technique. If properly used, this technique is
helpful in solving commonly encountered clinical
problems.
• A well-fabricated metal-ceramic pontic is strong,
is easy to keep clean, and looks natural. However,
mechanical failure can occur and often is
attributable to inadequate framework design.
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Failure of unsupported gingival
porcelain
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The principles of framework
design are
• The framework must provide a uniform
veneer of porcelain. Excessive thickness of
porcelain contributes to inadequate support
and predisposes to eventual fracture.
• 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.
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Waxing to anatomic contour and controlled
cutback (A) are the most reliable approaches to fabricating a
satisfactory metal substructure (B).
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• The metal surfaces to be veneered must be
smooth and free of pits. Surface irregularities
cause incomplete wetting by the porcelain slurry,
which leads to voids at the porcelain-metal
interface that 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.
• The occlusal centric contacts must be placed at
least 1.5 mm away from the metal ceramic
junction. Excursive eccentric contacts that might
deform the metal-ceramic interface must be
evaluated carefully.
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2. Resin-Veneered Pontics
• Historically, acrylic resin–veneered restorations
had deficiencies that made them acceptable only
as longer term interim restorations.
• Dimensional change from water absorption and
thermal fluctuations (thermocycling) caused
problems.
• No chemical bond existed between the resin and
the metal framework, and so the resin was
retained by mechanical means (i.e.,undercuts).
• Continuous dimensional change of the veneers
often caused leakage at the metal-resin interface,
with subsequent discoloration of the restoration
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• Nevertheless, there are certain advantages to using
polymeric materials instead of ceramics:
• They are easy to manipulate and repair and do not require
the high– melting range alloys needed for metal-ceramic
techniques.
• The newer-generation indirect resins have a higher
density of inorganic ceramic filler than do traditional direct
and indirect composite resins. Most are subjected to a
postcuring process that results in high flexural strength,
minimal polymerization shrinkage, and wear rates
comparable with those of tooth enamel.
• In addition, improvements in the bond between the
composite resin and metal may lead to a reappraisal of
resin veneers.
• Also High performance polymers (eg;- PEEK) are used for
bridge fabrications nowadays.
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3. Fiber reinforced composite resin pontics
4. All ceramic pontics.
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5. All-Metal Pontics
• require fewer laboratory
steps, sometimes used for
posterior FDPs. However, they
have some disadvantages
(e.g.,their appearance). In
addition, investing and casting
must be done carefully
because the mass of metal in
the pontic is prone to porosity
as the bulk increases. A
porous pontic retains plaque
and tarnishes and corrodes
rapidly.
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ESTHETIC CONSIDERATIONS
1. The Gingival Interface
• An esthetically successful pontic replicates 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 junction. The greatest challenge in this situation is
to compensate for anatomic changes that occur after extraction.
• To achieve a “natural” appearance, special attention should be paid
to the contour of the labial surface as it approaches the tissue-
pontic junction. This cannot be accomplished by merely duplication
of the facial contour of the missing tooth; after a tooth is removed,
the alveolar bone undergoes resorption or remodeling, or both.
• If the original tooth contour were followed, the pontic would look
unnaturally long incisogingivally.
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• Clinically, many pontics have suboptimal contour,
which results in an unnatural appearance. This can be
avoided with careful preparation at the diagnostic
waxing stage.
• Sometimes the ridge tissue must be surgically
reshaped to enhance the result.
• When appearance is of great concern, the ovate pontic,
used in conjunction with alveolar preservation or soft
tissue ridge augmentation, can provide an appearance
at the gingival interface that is virtually
indistinguishable from that of a natural tooth
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• 2. Incisogingival Length
• Correctly sizing a pontic simply by duplicating the
original tooth is not possible because Ridge
resorption makes such a pontic look too long in
the cervical region. So there are 3 options:-
• 1. The height of a tooth is immediately obvious
when the patient smiles and shows the gingival
margin . 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. The observer
sees a normal tooth length but is unaware of the
abnormal labial contour. The illusion is successful.
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2. shape the pontic to simulate a
normal crown and root with emphasis on the cementoenamel
junction. The root can be stained to simulate
exposed dentin
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3. use pink porcelain to simulate the gingival tissues
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• N,B ;- Ridge augmentation procedures have been
successful in correcting areas of limited
resorption. When bone loss is severe, the esthetic
result obtained with a partial removable dental
prosthesis is often better than that obtained with
an FDP.
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3. Mesiodistal Width
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• Frequently, the space available for a pontic is greater or
smaller than the width of the contralateral tooth. This is
usually because of uncontrolled tooth movement that
occurred when a tooth was removed and not replaced. So
we have 3 options :-
• 1. orthodontic treatment.
• 2. The retainers and the pontics can be proportioned to
minimize the discrepancy. ( diagnostic waxing procedure).
• 3. If this is not possible, an acceptable appearance may be
obtained by incorporating visual perception
principles into the pontic design.
• 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 a more natural size.
• The width of an anterior tooth is usually
identified by the relative positions of the
mesiofacial and distofacial line angles, and the
overall shape by the detailed pattern of
surface contour and light reflection between
these line angles.
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• The features of the contralateral tooth should
be duplicated as precisely as possible in the
pontic, and the space discrepancy can be
compensated by alteration in the shape of the
proximal areas.
• Space discrepancy presents less of a problem
when posterior teeth are being replaced
because their distal halves are not normally
visible from the front.
• A discrepancy here can be managed by
duplicating the visible mesial half of the tooth
and adjusting the size of the distal half
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Thank you
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