hi everyone in this video we'll be talking about conventional bridges when they're appropriate the
types of pontics and conventional bridges that we can prescribe the materials used to fabricate
these bridges and some complications that you should expect that might happen in the long run
so just before we get started we'd like to thank dr kushal guardia who is a consultant
in restorative dentistry and a specialist in periodontology prosthodontics endodontics
restorative dentistry and has a special interest in dental implantology dr guardia has been kind
enough to provide this content from ace courses and while this video is just a summary the full
webinar is available to students completely free of charge on his ace courses website
sign up link in the description below the first thing you want to be considering when treatment
planning is the length of the span you want to replace a gap which may have one or two teeth
missing or in some rare cases three teeth at the most you also need to consider the
positions of the missing teeth and whether they cross the midline or not other things to consider
are the periodontal surface area of the abutment teeth their endodontic status if they're mobile
the quantity and quality of tooth structure remaining if there are any restorations which are
present the patient's oral hygiene and periodontal status their occlusion and whether they have a
para functional habit if there's enough occlusal clearance and the crown to root ratio this is an
example of a patient who presented with a sports related injury the upper right central and lateral
incisor were of poor restorative prognosis and the upper left central incisor had an enamel
dentine fracture to do a conventional bridge in this case would be very destructive on the virgin
upper left canine and the near virgin upper left central some better options in this particular
case would be to do a cobalt chrome partial denture with an immediate acrylic denture a resin
retained bridge from the upper right canine to the upper left central or two implants to replace the
upper right incisors in this particular case the patient chose to go down the implant route but
you can achieve a similar aesthetic result with a resin bonded bridge if at a time of extraction
you are able to achieve socket preservation and maintain good soft tissue and bone volume
it's clear that apontek plays a huge role in improving the aesthetic outcome for the patient
but it's important to remember that it should also stabilize the occlusion and in turn be able
to withstand occlusal forces while also stopping over eruption of the opposing tooth it should also
improve the masticatory function for the patient the pontic should be designed in such a way which
means the area of the pontic the connector and the margin between the retainers and the
abutment teeth are all cleansable the first type of pontic design we'll cover isn't really done
anymore but you might see in a patient with an old bridge and it's called a sanitary pontic design
there is a large amount of clearance from the ridge this means that the patient can clean the
area really easily and it serves the functional purpose of a conventional bridge but the problem
is that it has very poor aesthetics if you ever needed to do this type of pontic it's preferred
to follow the contour of the ridge the next design we'll talk about is called the dome-shaped pontic
where its tip sits on the crest of the ridge and the modified version of this is called
the spheroidal shape where there is more contact onto the ridge the design which is most commonly
used is called the ridge lap or the modified rich laplantic the advantage of these are that
they're much more aesthetic and the difference between them is that the modified ridgelap
while easier to clean gets more food impaction under the pontic while the ridgelap is harder to
clean but gets less food impaction on the palatal or lingual side the last design we'll cover is
called the saddle pontic which covers more of the periodontal tissues and so is generally more
difficult to clean and would require superfloss dr guardia says that he would generally prefer to use
a spheroidal design before we move on to the next section i'd really appreciate it if you guys gave
this video a like and subscribe it really helps our channel grow and reach more people thank you
now we'll cover the different types of conventional bridges starting with a fixed
fixed design which utilizes rigid connectors at both ends of the pontics this can replace one to
two teeth and sometimes even three teeth spans but it's important to note that the longer the
span the more stress and flexing that happens on the bridge which increases the chances of failure
the abutment tee for this design need to be parallel which can also be difficult
to achieve over a longer span and also increases the chance of purple exposure if the teeth aren't
parallel the abutment teeth also need to have similar retention and resistance form so that
the forces can spread more evenly along the bridge generally a fixed fixed is actually not the best
option unless you're replacing a fixed-fix bridge already or unless the adjacent teeth are in need
of customer coverage that said you shouldn't be using root treated teeth as an abutment
this is an example of a failing fixed fixed bridge which had marginal defects and secondary carriers
replacing the upper right first premolar the upper right molar needed to be extracted these are the
pre-op clinical photos showing the marginal breakdown and you can also see a modified ridge
lab design for the pontic this is the post-op where the margins have been reprepped and
a new bridge has been made it's important to remember that there is a one in six chance
that the teeth may devitalize in which case you would need to endodontically treat this tooth as
we've said before you don't want to bridge a root tree a tooth so let's say the canine devitalizes
we would cantilever from the second premolar and crown the canine individually now instead let's
say the second premolar devitalized instead dr guardia doesn't like to do distal cantilevers so
in this case he would leave the abutments as crowns and fill the space using a different
method by placing an implant or a denture or alternatively accepting the gap the next type of
bridge we'll cover is called a fixed movable and this is where you have one rigid connector and a
movable connector on the other side which allows vertical movements only these are generally used
for longer spans where the angulation of the teeth are not parallel and the preps would be
very destructive in this case we introduced two different paths of insertion where we place the
first part followed by the second part of the bridge locking into the first part this is an
example replacing the premolars and first molar where there is a male component on the right
of the first molar and a female component on the left so the left side would have to be cemented in
first and then followed by the right side of the bridge where the patrick's inserts into the matrix
another type of bridge design would be the cantilever bridge where we only use one end of the
pontic this is generally good for anterior spaces and shouldn't really be done posteriorly because
there are more forces placed on the pontic we've spoken about this before but there should never
be any lateral excursive forces on pontics and there should only be a fairly light contact in icp
the next type of bridge design is a spring cantilever where the adjacent teeth are not
suitable as abutment teeth and so we need to use a tooth at a different site and these are really
done other designs include hybrid designs where you would use a combination of a conventional
prep on one side and a resin bonded retainer on the other side of the pontic removable
bridges can be removed to clean underneath and implant supportage bridges can also be done
in terms of materials dr guardia massively prefers to use pfm where you extend the porcelain up to
can depend on the opposing arch and if the person is a brook cyst for example
metal margins are also preferred if it's not in an aesthetic zone because they're so much
easier to clean for full porcelain bridges there needs to be more long-term studies to
evaluate the outcome but this is an option and it would be more conservative than a pfm
gold can be used but only in anaesthetic areas and is also more expensive
in terms of looting agents you can use any of the following on the screen now but also bear
in mind that zinc oxide eugenol is only used as a temporary cement there can be complications with
constructing bridges we've already mentioned that one in six teeth can be vitalized you also need to
be mindful of periodontal membrane space widening and bone loss due to unfavorable loading and from
a restorative standpoint these abutments are prone to secondary carries decementation and increased
chances of fracturing due to the increased loads okay guys we hope you found that video useful and
if you did we would really appreciate it if you gave this video a like and subscribe to
our channel there are more videos like this coming soon in line with the ace courses webinars created
by dr guardia for the full webinar make sure you check out the ace courses website
which is completely free of charge for students to use and contain some really interesting cases
which for time purposes we couldn't include in this video there's a link in the description to
sign up if you haven't done so already and we'll see you in the next video guys thank you thanks