Maryland bridge
Maryland bridge is a common prosthesis for patients that are too young or don’t have the bone for dental implants. Often they are done when a person is missing a lateral incisor. The lateral incisor is the small tooth right next to the center one. This is genetic, very common and it runs in families, so blame mom and dad!!
What are the marlyand bridge options?
The are several variations of the maryland bridge out there. Materials that we use are either metal, porcelain, or composite. The porcelain we use is usually zirconia or pure emax, both of these have pluses and minuses. I would recommend going with whatever your dentist recommends, provided they can show you before and after pictures of their own work that you find acceptable. My opinion on technique and material questions is that the best material in the world isn’t the best in the hands of someone that hasn’t used it before or doesn’t like it.
There are only a few major design decisions to make and you should ask your dentist what they prefer.
The questions to ask are
- One wing or two? We have had several one wings rotate so there does exist some complications with the single wing. These were done shortly after braces when the teeth were still settling and we believe that had something to do with it.
- Will you use metal or ceramic for the substructure support?
- Will the cosmetic part be made out of composite or ceramic?
- How deep is the overbite? An overbite of over 4mm is risky.
Alternatives to a Maryland bridge
The main alternatives are a dental implant. When we are talking Maryland, the patient is typically too young to get a dental implant. Another alternative is a cantilever dental bridge. This would be ideal for an older individual that can not do a dental implant due to bone loss or for someone that needs a crown on an adjacent tooth. The last option is a dental flipper. This is removable and not ideal unless finances are a major concern. They are meant to be temporary.
Porcelain fuse to metal Maryland bridge (PFM Maryland bridges)
This is what the vast majority of dentists use for their Maryland bridges. The material and technique is time tested and both labs and dentists are all familiar with it.
Emax maryland bridges
These are becoming more common but require more thickness to be strong enough. The ones that can be found online are in our opinion too bulky and unaesthetic.
Zirconia maryland bridges
These can be very good but one must worry about how well you are bonding to the tooth structure with zirconia. Some are creating methods to allow for porcelain to bond to the tooth and still utilizing the strength of the zirconia. This is accomplished through either holes in the zirconia that the lab fills with porcelain or porcelain circumferentially around the zirconia.
Kern shows some nice cases with zirconia. He uses ink to mark his tooth for preps and cleaning with air abrasion prior to bonding. Also uses the ink to mark the zirconia for air abrasion. The prep is one central divet and a small indention near the connector side.
Bonding the zirconia
After the try in
- Protect the porcelain with something like wax.
- Mark the intaglio with ink.
- Microetch the intaglio
- Primer with MDP then bond on zirconia and cure it
- Isolate, ink, then microetch the tooth.
- Etch the tooth then bond and cure the tooth.
- Dual cure resin cement.
Can also use an MDP cement like Panavia.
Composite Maryland bridge
A composite Maryland bridge is not very useful for most people. I only use if someone can not afford anything but the cheapest possible option. Even then I will only use it on someone that is very old and will likely not need it much longer. Usually it is a patient that is thinking of just leaving the space and doesn’t care very much. This patient often makes one of the funnier jokes I hear from very old patients, ” Honey, at my age I don’t even buy green bananas.”
Issues that make a maryland bridge more challenging
There are several things about you that can make a maryland bridge hard to do well.
First off is how hard are you on your teeth? Grinders, clenchers, people that have hard diets will pop these off on a regular basis. No one will be happy.
Where is your smile line? That means how much gum tissue do you show when you smile? If the answer is none, then the esthetics of where the tooth needs to look like it’s coming out of the gums is not that important. If you have a gummy smile it is going to be a challenge to get it to look natural. The best method will include some type of temporary to train the gum tissue.
The final issue is the amount of tissue and bone you have to work with. If there isn’t much tissue or bone then the dentist can’t make it look like it’s coming out of the gums naturally. Many people with little bone will have an indention in that area and it will never look natural without doing some sort of gum graft before the maryland bridge is made. The other issue with these indented areas is the tooth always looks darker as the lip casts a shadow on it because it sinks in more in that area.
Marlyand bridge before and after pictures
This is an example of two Maryland bridges that we did on a young girl. We are using a modified version of the traditional Maryland bridge in which we use only 1 wing. This method allows to only reduce the back side of one tooth instead of two. In this particular case these are her final restorations that she will have for as long as she can keep them.
Laser gum treatment for maryland bridges
It makes a big esthetic difference if you can train or treat the tissue before delivery of final maryland bridge. Ideally the final result looks like the tooth is coming out of the gums, not sitting on top of the gums. If you have very little bone and/or tissue width this may not be possible or be very challenging anyway. There are many times that the gums in the area of the maryland bridge will benefit from some gum treatment as well. A great example of this is below. The canine next to the maryland bridge now has a higher gum line that matches the other side. We use a laser to fix gum levels.
Creation of an ovate pontic with a laser is critical for a natural looking result. To maintain the ovate tissue you simply add to the retainer tooth the patient is wearing.
We also will shorten or bond to canines to make them more symmetrical as well. Again the case below is an example of this.
Maryland bridge information for dentist and lab
Connecting the maryland bridge to a cuspid and incisor is more likely to cause adhesion failure at the incisor. This adhesion failure can lead to decay if not detected. Best methd for the one wing is to connect it to the canine. Keep the prep in enamel with a Yamahita design. Use non-precious metal, like Rexillium III, sandblast it and bond with MDP containing material like Panavia. Keep the metal supraginigval due to metal sensitivity. Do not let the lab electrolytically etch the non-precious metal, you can just blast it with aluminum oxide before bonding it. Don’t wash off the residual sand, simply apply your MDP containing resin.
Panavia 21 to porcelain fused to metal Maryland bridge
Maryland bridge to base metal
- Sandblast 2-3 seconds per cm2. (30-50 micron alumina)
- Air dry
- Mix A and B for 35 seconds
- Place A and B on tooth for 60 seconds
- Air dry
- 1 full turn and mix cement 20-30 seconds
- Seat restoration with finger pressure for 60 seconds
- Place Oxyguard II for 3 minutes
- Clean up excess with scaler or explorer
What is a Yamashita prep design?
Yamashita adhesion bridges use intra-enamel grooves on mesial and distal. We heard about this on a dentaltown thread. In that thread it says Botelho et al. has a study showing the Yamashita prep design, but we do not see that in the study. Here is what the study says, “As this study was retrospective, it was not possible to describe the biomechanical variables of the prostheses, such as thickness of retainer and use of grooves, pins, or cingulum rests, and these variables were therefore not controlled.” Frankly, we can not find a great description or picture of it anywhere.
Despite that the prep design that we use has 2 retention spots and 1 retention groove. It forms a smiley face and my lab said it makes her happy so we like it.
This is another example of a retention prep that is from a popular course on dentaltown.
What is the Maryland bridge dental code?
The dental code for a Maryland bridge is actually going to be 2 or 3 dental codes depending on if we use 2 or 1 wing. The wing or retainer is dental code D6545 for metal and D6548 for porcelain, so think emax or zirconia. The pontic tooth is dental code D6242 for noble metal and D6245 for porcelain.