9 Pontics, Edentulous Ridges, Solder Joints, Connectors Flashcards
- the raison d’être of a fixed partial denture. Its name is derived
from the Latin pons, meaning bridge. - It is not a simple replacement because placing an exact
anatomical replica of the tooth in the space would be _____________________. - Porcelain
has been observed to be easily cleanable and hygienic,
and many clinicians have advocated ____________ as the preferred, or only, material that should touch the edentulous ridge - Because of the
porous nature of _____ and the difficulty in maintaining a highly polished surface on it, resins should
not be used on pontics near the tissue. Glazed or highly polished porcelain and gold with a _______________finish are preferred for tissue contact. - _____________ is more important to cleanability and good tissue health than is the choice of
materials. The surrounding tissues change with the loss of a tooth; therefore, a pontic cannot exactly
duplicate the lost tooth. _______________________ reshape the edentulous area, rounding
over sharp edges and filling the socket itself. If there is trauma or periodontal disease associated with the loss of the tooth, the final healed ridge shape may be an even greater departure from the original configuration - Because some of the supporting tissues are lost when the tooth is removed, and because the pontic ___________________ instead of growing from it, modifications must be made in basic tooth morphology to ensure that the pontic will be cleanable and noninjurious to soft tissues
- The contours in the _________________________________ cannot match those of the tooth that originally
occupied the space or those of the remaining natural teeth (Fig 25-2). If they do, the facial surface
will be too ____ and will look artificial (Fig 25-3). The pontic must be shortened apically, but it
cannot simply be clipped off because the result would be an __________________ (Fig 25-
4). The facial surface must be altered to _____ gently from the gingivofacial angle to the middle of the
facial surface (Fig 25-5).
- pontic, or artificial tooth
- hygienically unmanageable
- glazed porcelain
- resin; mirror-like
- Proper design; Alveolar resorption and remodeling
- lies over the tissue;
- apical half of the facial surface ; long; uncleanable gingivofacial ledge; curve
- The ____________ of the pontic contact with the ridge is very important. _________________
has been cited as a major factor in the failure of fixed partial dentures. There is widespread agreement that the area of contact between the pontic and the ridge should be ____ and the portion of the pontic touching the ridge should be as ______ as possible - However, if there is contact along the gingivofacial angle of the pontic, there must be ________ between pontic and soft tissue on the facial side of the ridge. If the tip of the pontic extends past the mucogingival junction, an _______ will form there. The pontic should contact only ____________________
- The once-popular practice of __________________ on the cast to obtain close adaptation of the pontic
with tissue compression is not indicated because the resultant pressure on the ridge is likely to cause
________________. It is generally accepted that the pontic should exert ___________ on the ridge. One
author has gone so far as to suggest that the contact be with the film of saliva on the ridge. Others
flatly state that the pontic should not contact the tissue at all. However, pontics not contacting the
ridge at the time of insertion of a prosthesis may become surrounded by _____________ over
time in the mouth - Although one study has shown that the tissues under a pontic can be maintained in an inflammation-free state if the patient flosses vigorously at least once a day, there will be an _____________________ of the pontic on the ridge even without inflammation. There is an increased risk of clinical failure if success depends too much on a patient’s cooperation.
- extent and shape; Excessive tissue contact; small; convex
- no space; ulcer ; attached
keratinized gingiva - scraping the ridge; inflammation.; no pressure; hypertrophied tissue
- imprint, or “footprint,”
- The mesial, distal, and lingual gingival embrasures of the pontic should be wide open to allow the
patient _______________, and the contact between pontic and tissue must allow the ___________ from one retainer to the other. After the fixed partial denture is cemented, the patient
should be taught appropriate technique(s) that can be mastered. The individual should be motivated to
practice ____________ around and under the pontic with dental floss (Fig 25-8), interproximal brushes
(Fig 25-9), or pipe cleaners. The method used will depend on embrasure size, accessibility, and
patient skill. - The patient should be given time to learn the techniques and demonstrate the ability to clean the underside of the pontic and the adjacent areas of the abutment teeth. _________ is evaluated at each appointment, and the necessity for good hygiene and the skills to accomplish it are reinforced. Even the smoothest pontic surface must be cleaned well and often to prevent the accumulation of _______. If cleaning is not done at frequent, regular intervals, the tissue around the pontic will become
_________. - Pontics designed for placement in highly visible areas (called the ___________________________) must produce the illusion of being teeth,
esthetically, without compromising cleanability. Those pontics placed in less visible areas (usually
mandibular posterior replacements) are there to restore function and prevent the drifting of teeth.
Because esthetics is usually a minor consideration in this area of the mouth, it may not be necessary to
utilize materials or contours that suggest the presence of a tooth - The pontic should be on as ______________ as possible between the retainers to prevent any________
of the retainers and/or abutments. The pontic will be slightly narrower than the natural tooth, partly
because of the effort to place it on the ______________. The pontic may also be somewhat narrower at the expense of the lingual surface in an effort to avoid the formation of an uncleanable, overhanging shelf in the pontic overlying the lingual aspect of the ridge. However, no attempt is made to make the pontic narrower by a set percentage (eg, 10% per pontic). Doing so does not alter the plaque index. Narrowing the pontic is not practical if an effort is being made to maintain occlusal contacts on cusps or in fossae.
- easy access for cleaning; passage of floss; good hygiene ;
- Home care; plaque; inflamed
- esthetic zone or the appearance
zone; - straight a line ; torquing; interabutment axis;
There are several designs available for use in situations requiring pontics in the fabrication of
fixed partial dentures. These include: (7)
- saddle (ridge lap),
- modified ridge lap,
- hygienic,
- conical,
- ovate,
- prefabricated pontic facings,
- metal-ceramic pontics.
The _________ pontic looks most like a tooth, replacing all the contours of the missing tooth. It forms a
____________________ with the ridge (Fig 25-10a), obliterating the facial, lingual, and proximal
embrasures. It is also called a ____________ because it overlaps the facial and lingual aspects of the
ridge. 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 (Fig 25-10b). This
design has long been recognized as being __________________,
22 and it still is.
23,24 The saddle is
impossible to clean because floss cannot traverse the tissue-facing area of the pontic, which bridges
the linguogingival and faciogingival angles of the pontic. The saddle causes _______________, and
it should not be used
saddle
large concave contact
ridge lap
unclean and uncleanable
tissue inflammation
The ______________ design gives the illusion of a tooth, but it possesses all or nearly all convex
surfaces for ease of cleaning. The ______________ should have a slight deflective contour to prevent
food impaction and minimize plaque accumulation.
14 There may be a slight _______________ 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.
Ridge contact must extend no farther lingually than the midline of the edentulous ridge, even on
posterior teeth. 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.
This design, with a porcelain veneer, is the most commonly used pontic design in the _____________ for
both maxillary and mandibular fixed partial dentures
modified ridge lap
lingual surface
faciolingual concavity
esthetic zone
The term ___________ is used to describe pontics that have no contact with the edentulous ridge (Fig
25-12). This pontic design is frequently called a _____________ which in years past was the trade
name for a prefabricated, convex facing with a slot back, used for mandibular molar pontics.
The hygienic pontic is used in areas that are not easily visible, particularly for replacing
_____________. It restores occlusal function and stabilizes adjacent and opposing teeth. If
there is no requirement for esthetics, it can be made entirely of metal. The occlusogingival thickness
of the pontic should be _______________________, and there should be adequate space under it to facilitate cleaning. The hygienic pontic is frequently made in an __________ configuration, faciolingually and
mesiodistally.
Making the undersurface of the pontic ________ without angles allows for easier flossing (Fig 25-13a).
It is more difficult to get floss to pass over a flat undersurface evenly or to get over sharp
faciogingival and linguogingival line angles (Fig 25-13b). 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 concave archway mesiodistally
(Fig 25-14b), has been suggested. 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.
26 Stress is reduced significantly in the
connectors, and deflection is diminished in the center of the pontic, with less gold used.
27 An esthetic
version of this pontic can be created by veneering with porcelain those parts of the pontic that are
likely to be visible: the ______________________________________________, which happens to
be all of the facial surface on this pontic. This design has been called an _________________,
23
a modified sanitary pontic,
27 or simply a Perel pontic
hygienic
“sanitary pontic,”
mandibular first molars.
no less than 3.0 mm
all-convex
round
“fish belly”
hyperbolic paraboloid
occlusal surface and the occlusal half of the facial surface
arc-fixed partial denture
- The _________ pontic 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 ________________ (Fig 25-15a). However, when used with a broad, flat ridge, the resulting large _______________spaces around the tissue contact have
a tendency to collect debris (Fig 25-15b). This pontic is related to the “_______________” described
by Tinker in 1918. Its use is limited to replacement of teeth over ________ in areas that are not
highly visible. - The __________ pontic is a round-end design currently in use where esthetics is a primary concern. Its
antecedent was the ________________, which was used considerably before 1930 as an esthetic and sanitary substitute for the saddle pontic. The tissue-contacting segment of the ovate
pontic is bluntly rounded, and it is set into a concavity in the ridge (Fig 25-16). It is easily flossed. The _____________ 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. This pontic works well with a _____________ , giving the appearance that it is growing from the ridge.
- conical; thin mandibular ridge; triangular embrasure ; sanitary dummy; thin ridges
- ovate; porcelain root-tipped pontic; concavity ; broad, flat ridge
- Historically, _____________________ were popular for fabricating pontics. They required adaptation to a specific edentulous space, after which they were reglazed.
- Some, such as
Trupontics, Sanitary Pontics, and Steele’s Facings (Franklin Dental), relied on a lug in a custom cast
metal backing to engage a slot in the occlusal or lingual surface of the facing (Fig 25-17a)_______________________ . The large
bulk of porcelain could result in a thin gold backing susceptible to flexing. Harmony (Harmony
Dental) and Trubyte (Dentsply) facings used _______________ that fit into the gold backing (Fig 25-
17b). They were difficult to use in patients with limited occlusogingival space, and refitting the pins
into a backing after casting was demanding. - __________________ also were modified to use as pontic facings. Multiple pinholes 2.0 mm
deep were made with a drill press in the lingual surface of the _______________
33
(Fig 25-18). The
pins protruded from the backing, providing retention where a deep overbite would have
overshortened conventional pins. Unfortunately, the pinholes in the facing were stress points that led
to fracture.
- preformed porcelain facings
- slot-back; (b) (Harmony) horzontal pin facing
- Porcelain denture teeth; reverse pin facing
With the widespread use of metal-ceramic restorations, metal-ceramic pontics have replaced other
types of pontics employing porcelain. Metal-ceramic pontics have the greatest ___________________ as
prosthetic replacements for missing teeth.
34 Additionally, metal-ceramic pontics are __________ because
the porcelain is bonded to the metal substrate rather than cemented to it. 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).
esthetic potential
stronger
- Before a fixed partial denture is undertaken, the ________________ should be examined carefully.
The type and amount of destruction that has occurred will play a role in selecting the pontic to be
used and also may indicate the necessity for reshaping the ridge surgically - Ridge deformities have been grouped into three categories by Seibert, and this
classification has been widely accepted (3 plus 1)
- edentulous ridge;
- Class I: Loss of faciolingual ridge width with normal apico-coronal height
Class II: Loss of ridge height with normal width
Class III: Loss of both ridge width and height
“normal” classification (Class N) with minimal deformity
- At one time, it was common to modify a pontic to fit an edentulous space, no matter what the
esthetic consequences were. Developments in surgical techniques have made it simpler to change the
configuration of a ridge to create a more esthetic and easily cleanable shape. It has become more
common to _____________ than to suffer the rigors of “making do” with a deficient ridge. - There are nonetheless situations in which a more conservative approach may be desired. The patient’s inability to undergo surgery, or an unwillingness to consider it, will force the consideration of an alternative form of _______ In ridges with severe defects, where two or more pontics must be used to fill the space, it is not uncommon to eliminate ______________ spaces between the pontics.
- So-called ___________ can be very unesthetic (Fig 25-20), and they serve no useful purpose. They collect plaque, interfere with the passage of floss, and may reduce the rigidity of the pontic span. _____________ can be added to the gingival embrasure area of the pontic to simulate
interdental papilla, although the shade rarely matches the particular hue of thepatient’s gingiva. The gingival extension of porcelain must be supported by the ______________ If
not, all of the gingival porcelain, as well as much of the facial porcelain, is at risk of fracturing. Elimination of interpontic gingival embrasures in a multitooth pontic may limit or eliminate soft tissue
_____________.
Embrasure spaces filled with porcelain can be satisfactory when replacing mandibular molars and mandibular incisors, where the gingival area is not subject to close scrutiny. However, it is more difficult to achieve an esthetic result simply by modification of the embrasure spaces in a highprofile area such as the maxillary incisor region (Fig 25-22). In the presence of a large deformity,
an unmodified pontic would leave large, unsightly gingival embrasures (Fig 25-23), and the addition
of a gingival flange may be too conspicuous (Fig 25-24). - One solution used in the restoration of large ridge defects, particularly in the anterior segment, is
the _________________. It uses fixed retainers that are connected by a rectangular bar that follows the curve of the ridge under it (Fig 25-25). The prosthesis consists of teeth set in a patient-removable flange of gingiva-colored acrylic resin that clips over and is stabilized by the rectangular
bar. Unfortunately, the flange is a food and plaque trap that is difficult to keep clean. In spite of its drawbacks, it still may be the best way of handling some large ridge defects
- modify the ridge
- pontic.; gingival embrasure
- black triangles; Pink porcelain; metal framework.;proliferation
- Andrews bridge system;
Ridge augmentation can be accomplished by the addition of soft or hard tissue, although filling a
ridge defect with bone is not essential unless the ridge is to be used for _______________.
45 Excellent esthetic
results in Class I defects can be obtained by connective tissue plastic surgery in the form of a
_______________________________.
Unfortunately, apicocoronal Class II and Class III defects cannot be adequately treated by a pouch
type of ridge augmentation. These types of defects are better treated using an onlay graft, which
Seibert describes as a ________________.
implants
subepithelial or submucosal connective tissue graft
thick free gingival graft
Metal frameworks or copings for metal-ceramic fixed partial dentures should be constructed with
these requirements in mind:
(1) There must be an adequate bulk of _____ to ensure rigidity for
strength, and
(2) porcelain should be of nearly _____________ throughout to avoid the possibility of
weakening the porcelain through uneven stress concentrations.
To meet these requirements, there
should be a continuous strip of exposed __________________, extending from the metal portion
of one retainer, across the lingual of the pontic, to the metal portion of the other retainer.
metal
equal thickness
metal on the lingual surface
- _____________ is the joining of metal components by a filler metal, or solder, which is fused to each of
the parts being joined. Strictly speaking, if the filler metal has a melting temperature greater than
450°C (840°F), the process is called _____________. Bonding is contingent on wetting of the joined surfaces by the solder and not on melting of the metal components. When a solder joint is done properly, there should be no
fusion or alteration of the two components joined. Soldering differs in that respect from welding,
another means of joining metals. In _________________, the pieces that are joined are melted or fused
together, without solder. - Solder can be used for joining, as in the fabrication of a fixed partial denture, or it can be used for
building, as when an addition is made to the proximal surface of a crown. _____________ is the prime
prerequisite of soldering, inasmuch as the soldering process depends on ______ of the surface to
achieve bonding. Corrosion products, such as _____________, that are present as a result of the
casting process or that occur on the surface of metals when they are heated interfere with bonding - ______ is placed on the surfaces to be soldered before they are heated. Fluxes may provide surface
protection, reduce oxides, or dissolve oxides. Flux is displaced by solder, which then can form an
interface with and bond to the surface being soldered. Soldering fluxes for noble metals are based on
___________. They form low-fusing glasses that protect the metal surface, and they also reduce
oxides such as copper oxide. They often are too fluid for preceramic soldering. _________ are used
on base metal alloys to dissolve the stable oxides of chromium, cobalt, and nickel. In addition to
acting as solvents, these fluxes also serve a protective role. - Flux is more easily applied if it is in ________________. While a flux paste can be made with alcohol, the
most popular form for use with noble metal alloys employs __________ as a vehicle because it is more
easily handled. It keeps air from the flux, and, when heated, the petrolatum burns off without leaving
any residue. Fluxes made from common borax, or pastes made with water, tend to effloresce when
they are heated, producing ____ in the solder joint. - ___________ is a material used to outline the area to be soldered in order to restrict the flow of solder.
The most common antiflux is the mark of a soft graphite pencil, which works best on surfaces that do
not have a high polish. Polishing rouge (iron oxide) suspended in chloroform can also be painted around the area of the solder joint to prevent undesired spread of the solder. - Gold solders are classified by fineness and by carat. ___________ refers to parts per thousand of the
solder that is gold. For example, a 600 fine solder would be 600 parts gold per 1,000, or 60% gold.
When used to designate a casting alloy, _______ refers to parts per 24 of a metal that are gold. As an
example, an alloy that is 18 K is 18 parts gold per 24, or 75% gold. When used with solder, however,
carat has a different meaning. A solder that is designated as 18 K does not have a 75% content of
gold. Instead, the 18 K designation means that it was formulated to be used with 18 K casting alloys.
The actual noble metal content of the solder would be given by its ____________ rather than by its carat.
The higher the fineness of a solder, the higher will be its ____________ and the greater its ____________________. While a solder with a lower fineness has a lower melting range, it also has ___________ characteristics
- Soldering; brazing; fusion welding
- Cleanliness; wetting; oxides and sulfides
- Flux; borate compounds; Fluorides
- paste form; petrolatum; pits
- Antiflux;
- Fineness; carat; fineness; melting range; corrosion
resistance; poorer flow
