Lec 9 Pontic Designs Flashcards
Looks most like a tooth, replacing all the contours of the missing tooth.
Saddle
It forms a large concave contact with the ridge, obliterating the facial, lingual, and proximal embrasures
Saddle
It is also called a ridge lap because it overlaps the facial and lingual aspects of the ridge.
Saddle
A contact with the ridge that extends beyond the midline of the edentulous ridge, or a sharp angle at the linguogingival aspect of the tissue contact, constitutes a __________.
Ridge lap
This design has long been recognized as being unclean and uncleanable, and it still is.
Saddle
Impossible to clean because floss cannot traverse the tissue-facing area of the pontic, which bridges the linguogingival and faciogingival angles of the pontic. It causes tissue inflammation, and it SHOULD NOT BE USED.
Saddle
Gives the illusion of a tooth, but it possesses all or nearly all convex surfaces for ease of cleaning.
Modified ridge lap
What design?
The __________ surface should have a slight deflective contour to prevent food impaction and minimize plaque accumulation.
- Modified ridge lap
- lingual surface
There may be a slight faciolingual concavity on the facial side of the ridge, which can be cleaned and tolerated by the tissue as long as the tissue contact is narrow mesiodistally and faciolingually.
Modified ridge lap
Ridge contact must extend no farther lingually than the midline of the edentulous ridge, even on posterior teeth.
Modified ridge lap
Whenever possible, the contour of the tissue-contacting area of the pontic should be CONVEX, even if a small amount of soft tissue on the ridge must be surgically removed to facilitate it.
Modified ridge lap
This design, with a _____________, is the most commonly used pontic design in the esthetic zone for both maxillary and mandibular fixed partial dentures.
- Modified ridge lap
- porcelain veneer
The term ________ is used to describe pontics that have no contact with the edentulous ridge.
hygienic
This pontic design is frequently called a “sanitary pontic,” which in years past was the trade name for a prefabricated, convex facing with a slot back, used for mandibular molar pontics.
Hygienic
Used in areas that are not easily visible, particularly for replacing mandibular first molars. It restores occlusal function and stabilizes adjacent and opposing teeth.
Hygienic
If there is no requirement for esthetics, it can be made entirely of metal.
Hygienic
The occlusogingival thickness of the pontic should be no less than 3.0 mm, and there should be adequate space under it to facilitate cleaning. Frequently made in an all-convex configuration, faciolingually and mesiodistally. Making the undersurface of the pontic round without angles allows for easier flossing.
Hygienic
The round design has been described as a “_________-” (Fig 25-14a). An alternative design, in which the pontic is made in the form of a ________________ has been suggested.
fish belly
concave archway mesiodistally
hygienic design
The undersurface of the pontic is convex faciolingually, giving the tissue-facing surface of the pontic the configuration of a _______________. There is added bulk for strength in the connectors, and access for cleaning is good. Stress is reduced significantly in the connectors, and deflection is diminished in the center of the pontic, with less gold used.
hyperbolic paraboloid
hygienic design
An esthetic version of this pontic can be created by _______________ those parts of the pontic that are likely to be visible: the ________ surface and the occlusal half of the___________ surface, which happens to be all of the facial surface on this pontic.
veneering with porcelain
occlusal
facial
hygienic design
This design has been called an arc-fixed partial denture, a modified sanitary pontic, or simply a Perel pontic.
Hygienic design
Is rounded and cleanable, but the tip is small in relation to the overall size of the pontic. It is well suited for use on a thin mandibular ridge.
Conical
When used with a broad, flat ridge, the resulting large triangular embrasure spaces around the tissue contact have a tendency to collect debris.
Conical
This pontic is related to the “sanitary dummy” described by Tinker in 1918.
Conical
Its use is limited to replacement of teeth over thin ridges in areas that are not highly visible.
Conical
A round-end design currently in use where esthetics is a primary concern.
Ovate
The antecedent of the ovate design was the _______________, which was used considerably before 1930 as an esthetic and sanitary substitute for the saddle pontic.
porcelain root-tipped pontic
The tissue-contacting segment is bluntly rounded, and it is set into a concavity in the ridge. It is easily flossed.
Ovate
The concavity can be created by placement of a provisional fixed partial denture with the pontic extending one-quarter of the way into the socket immediately after extraction of the tooth. It also can be created surgically at some later time.
Ovate
This pontic works well with a broad, flat ridge, giving the appearance that it is growing from the ridge.
Ovate
Historically, they were popular for fabricating pontics. They required adaptation to a specific edentulous space, after which they were reglazed.
preformed porcelain facings
Relied on a lug in a custom cast metal backing to engage a slot in the occlusal or lingual surface of the facing.
preformed porcelain facings
The large bulk of porcelain could result in a thin gold backing susceptible to flexing.
Some used horizontal pins that fit into the gold backing. They were difficult to use in patients with limited occlusogingival space, and refitting the pins into a backing after casting was demanding.
preformed porcelain facings
______________ teeth also were modified to use as pontic facings. Multiple pinholes _______ deep were made with a drill press in the lingual surface of the reverse pin facing .
The pins protruded from the backing, providing retention where a deep overbite would have overshortened conventional pins. Unfortunately, the pinholes in the facing were _________ that led to fracture.
- Porcelain denture
- 2.0mm deep
- stress points
Have replaced other types of pontics employing porcelain.
Metal-ceramic pontics
- Have the greatest esthetic potential as prosthetic replacements for missing teeth.
- Stronger because the porcelain is bonded to the metal substrate rather than cemented to it.
Metal-ceramic pontics
They are easier to use because the backing is custom made for a space (no need to adapt a premade porcelain facing to the space).
Metal-ceramic pontics
