Pontic

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Lect.7 Crown and Bridge Dr.Ameer Hamdi AL-Ameedee
? Pontic definition:
Pontic: An artificial tooth that suspended member of the fixed dental prosthesis that replaces a
missing natural tooth, restores its esthetic and function, it replaces the space previously occupied by
the missing clinical crown. They must be compatible with continued oral health and comfort. The part
that connects the pontic to the abutment is the retainer which is either:
1- The rigid (ex. fixed by solder joint) the retainer is called major retainer.
2- When the connection is not rigid (flexible) ex. stress breaker, the retainer is called minor
retainer.
Ancient Phoenician (bridge)
Pontics are extracted central
and lateral incisors that are
attached to the remaining
canines with wires.
A, A three-unit FPD showing the main components.
B, The pontic rigidly attached to crowns on the abutment teeth. The connectors should occupy
the normal interproximal contact area and be large enough for strength but not so large as to
impede plaque control.
? Requirements of pontics:
1- Smooth surfaced and convex in all directions.
2- Easily cleansable.
3- Pinpoint pressure free contact on the ridge.
4- No irritation to the gingival tissues.
5- Facilitate plaque control.
6- Pontic space.
7- Strength and longevity.
8- Be esthetic.
9- Restore function.
10- No abutment overloading.
11- Color stable.
12- Residual ridge contour.
? Functions of pontics:
1- Mastication.
2- Occlusion.
3- Speech.
4- Esthetics.
? The components of pontic:
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a-Metal backing.
b-Solder joint.
c-Facing.
? The surfaces of a pontic: A pontic has five surfaces:
* The ridge.
* The occlusal.
* The approximal.
* The buccal.
* The lingual.
? Pontic Design:
Proper preparation includes a careful analysis of the critical dimensions of the edentulous areas:
mesiodistal
width, occlusocervical distance, buccolingual diameter, and location of the residual ridge. To design a
pontic that will meet hygienic requirements and prevent irritation of the residual ridge, particular
attention must be given to the form and shape of the gingival surface. The selection of the design
depends on the following factors:
a- Spatial boundaries
b- Shape of edentulous ridge (normal, blunted, or excessive resorption).
c- Maxillary or mandibular posterior arch (in contrast to the mandibular posterior pontic, the maxillary
edentulous ridge is usually broad and blunted and has superior cosmetic effects).
d- Anterior pontic (the overriding cosmetic requirement is that form and shape reproduce the facial
characteristics of the natural tooth).
The task is to design within boundaries of a tooth substitute that favorably compares in form,
function, and appearance with the tooth it replaces. The tooth substitute must provide comfort and
support to the adjacent musculature, conformity to the food-flow pattern, convenient contours for
hygiene, and cosmetic value, if indicated.
1-The relationship of poetic design to residual ridge:
A, Ridge lap pontic. This type of poetic demonstrates unacceptable excess tissue contact
and is difficult to maintain hygienically.
B, Modified ridge lap poetic. This type of poetic demonstrates acceptable esthetics and
works best with broad edentulous ridges.
C, Stein pontic. This type of poetic, which is designed for sharp edentulous ridges,
demonstrates minimal tissue contact and acceptable esthetics. It is contraindicated in edentulous
ridges with broad bucco-lingual dimensions.
D, Sanitary pontic. This type of poetic is 2 to 3 mm distant from the ridge. This design is
easily cleaned and allows for a free flow of food beneath the poetic. However, it exhibits
unacceptable esthetics.
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E, Ovate pontic. This type of poetic exhibits excellent esthetics and function. It produces
minimal tissue contact and is very hygienic. However, if ridge resorption occurs, deterioration of
esthetics results.
2-Interproximal contact areas are constructed wider buccolingually than the solder joint of the
permanent splint to provide strength for the splint. The tissue-contacting surface of a pontic must be
flat or convex (never concave) to permit efficient cleansing with floss and other home care devices.
3-Edentulous ridge.
4-Opposing occlusal surface.
5- Musculature of tongue, cheeks, or lips.
6- The sanitary pontic design leaves space between poetic and ridge.
7- The saddle pontic design covers the ridge labiolingually. Total coronal width is usually
concave.
8- The modified ridge design uses a ridge lap for minimal ridge contact. Labial contact is
usually to height of the ridge contour (straight emergence profile).
Proper pontic contour (tissue side) is conducive to cleansing
with dental floss.
The deflection of a fixed partial denture is proportional to the
cube of the length of its span.
A, A single pontic will deflect a small amount (D) when
subjected to a certain force (F).
B, Two pontics will deflect 23 times as much (8 D) to the same
force.
C, Three pontics will deflect 33 times as much (27 D).
? A- Biologic considerations:
1- Ridge contact: Area of contact with ridge should be small and convex.
2- Oral hygiene considerations.
3- Pontic materials: Differences in the plaque-retaining capacities of samples of a Type III
gold, gold for veneering with porcelain, a vacuum-fired bonded porcelain Veneer, and an
acrylic resin.
4- Occlusal forces: Reduce bucco-lingual width about 30% to lessen occlusal forces and will
increase 12%in chewing efficiency.
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B-Mechanical considerations:
1- Improper choice of materials.
2- Poor framework design.
3- Poor tooth preparation.
4- Poor occlusion.
5- It can be seen that the maximum tensile stress at the solder joint.
C- Esthetic considerations
1-Incisogingival length.
2- Root can be stained to simulate exposed dentine.
3- Pink porcelain to simulate the gingival tissues.
An abnormally sized anterior pontic
space can be restored esthetically by
matching the location of the line angles
and adjusting the interproximal areas.
Large (A) and small (B) pontic spaces.
L Dimension a should be matched in
the replacement.
? Classification:
1. Depending on shape of surface contacting the ridge:
a- Sanitary.
b- Modified sanitary.
c- Spheroidal
d- Saddle.
e- Ridge lap.
f- Modified ridge lap.
g- Ovate.
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A, Sanitary pontic.
B and C, Modified sanitary pontic.
D, Placement of the pontic, close to the ridge, has
resulted in tissue proliferation (arrow).
A, Cross-section view of ridge lap pontic.
B, The tissue surface is inaccessible to cleaning
devices.
A and B, FPD with a ridge-lap (concave)
gingival surface.
C, When it was removed, the tissue was
found to be ulcerated.
D, The defective FPD was recontoured and
used as a provisional restoration while the
definitive restoration was being fabricated.
Modified ridge lap pontic.
A, FPD partially seated.
B, FPD seated.
A and B, A pontic with maximum convexity and single point
contact of the tissue surface is the easiest design to keep
clean.
C, Evaluating the contour of three possible pontic shapes (1,
2, and 3). Contour 3 is the most convex in area B but is too
flat in area A. Contour 1 is convex in area A but is too flat in
area B. Contour 2 is the best.
D, An all-metal FPD with a conical pontic, suitable for
replacement of a mandibular molar.
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A, Conical pontics may create food entrapment on broad
residual ridges (arrow).
B, The sanitary pontic form may be a better alternative.
Ovate pontic.
A, FPD partially seated.
B, FPD seated.
2. According to Rosenstiel depending on mucosal contact.
a- Mucosal contact ridge lap modified ridge lap ovate conical (contact):
1-Saddle pontic.
2-Ridge lap
3-Modified ridge lap.
4-Ovate.
b- No mucosal contact sanitary(hygienic) modified sanitary (non-contact):
1-Hygienic (sanitary).
2-Modified sanitary (pearl pontic).
3-Bullet (conical or spheroid).
? Modified ovate pontic:
a- Contact more labially than ovate pontic.
b- Easier to clean.
c- No need of surgical augmentation.
d- Push the labial gingival margin away to floss.
? Residual ridge contour:
a- To determine the frequency and the nature of tissue reactions of underlying residual ridge
mucosa to specific pontic designs.
b-To compare the frequency and the nature of tissue reactions of residual ridge mucosa to
various materials used in pontic construction.