Hi jR,
Here's what Dr. Stein has to say:
"I'm more than happy to reply. Keep in mind that I haven't examined your mouth so all information is coming from you and is only as accurate as your lay recollection.
First, let me say that whenever I see a cracked filling I have reason for concern. This has nothing to do with diving.
A cracked filling is an entry point for decay bacteria and in the majority of cases, there will be decay under the fractured filling. In your case, the fractured filling overlies the filled root canal space. The bacteria that can enter this space not only can cause decay, they can also lead to a recurrent root infection. Oral bacterial contamination is the most common cause of root canal failure.
A cracked filling may also be the "tip of the iceberg" in that the crack may be present because the underlying tooth is cracked and the filling is "collapsing" into the tooth as the root pieces microscopically separate during function. If this is the case, then the prognosis for this tooth is poor. The only way to see if the tooth is fractured under the filling is to remove the filling and visually inspect the underlying surfaces. If the tooth is indeed fractured, then you will most likely have to extract the tooth. You might try a post/core and cap but even this may fail if the fracture is through-and-through.
In most cases, a permanent filling is NOT the treatment of choice for a root canaled tooth. Especially if the tooth is a bicuspid or molar (in the back of the mouth). The tooth needing a root canal is usually a heavily filled and/or fractured tooth in which the nerve has become devitalized or infected. Additionally, the root canal procedure removes even more tooth to open into the nerve chamber and therefore leaves less sound tooth structure for restoration. Although you can get a filling back into the tooth, it will not reinforce the remains of the tooth for long. A post and core with a crown is a stronger restoration then any kind of filling. The only real exceptions are upper and lower front teeth that have had a nerve die due to trauma without fracturing the tooth. Then the root canal access opening is rather small and a filling may suffice... front teeth are not subject to the same forces as the back teeth unless the patient has unnaturally strong bite forces.
Now, as for diving with a fractured filling... Assuming that the underlying tooth is not fractured and the root canal filling seal is in tact... you will experience no pain. However, if there is an underlying fracture or the root canal seal is leaking, then air can be forced into these spaces and pain may result. In fact, there may be enough trapped air in a tooth to shatter it when you ascend! This will ruin the tooth for any restoration.
While this outcome is very rare and fractures in teeth are very common, to knowingly dive with a failing filling in a tooth can really ruin a dive or a vacation.
If you weren't a diver, and you aren't in any pain, then a fractured filling is not an acute emergency and should be handled as a needed routine procedure. The fact that you are going to subject this tooth to a hyperbaric environment changes everything and I would treat this problem as soon as possible.
I am not trying to belittle you current dentist's advice. I philosophically don't agree with his assessment of this problem based on the fact that I have examined, treated and corresponded with individuals who have experienced a barotrauma from a fractured filling or fractured tooth. Most dentists have heard about barodontalgia due to scuba diving but have never actually seen a case. Therefore their own dental experience with this problem would lead them to believe that is is not serious and can be treated when the time allows. I would advise immediate treatment to minimize any risk.
Keep in mind that fractured teeth almost never are visible on x-rays until the tooth needs to be extracted. Fractured teeth are often the real reason that a nerve dies in a tooth and therefore needs a root canal procedure. Not all fractured teeth are visible in the mouth. Air spaces under fillings or within teeth are usually microscopic and cannot be found. It is simply not possible to predict when of if a tooth will become symptomatic during scuba diving.
Hope this helps.
Laurence Stein, DDS"
Regards,
DocVikingo
