Because of Boyle’s Law, (as pressure increases, volume decreases and vice versa), diving with air-filled spaces in teeth cause problems because spaces inside teeth cannot decrease in size and increase in size in proportion to the depth under the surface. Because we are already functioning at one ATM of pressure on the surface, a dive to 99 feet would increase the pressure inside the cavity to 4 atm absolute, a pressure of 58.6 lb/sq. in.
This increase in pressure would cause pain or barodontalgia and can severely limit a diver from functioning underwater.
Conditions that can allow air to enter into the interior of the tooth can cause barodontalgia, including caries, defective margins of restorations, periodontal abscesses, maxillary sinus congestion, pulpal lesions and endodontic therapy.
Teeth that have been opened for endodontic treatment and temporarily sealed have been known to explode from air trapping and expansion on surfacing. This is referred to as odontocrexis and is found to be more common in deep divers using a heliox mixture. Full porcelain crowns can also shatter from relatively shallow dives of 65 feet. It is suspected that trapped air is a very efficient crown remover in teeth where the cement bond is failing. Meticulous oral health is advised for divers actively engaged in scuba diving and to avoid barodontalgia, all carious lesions should be restored, ill-fitting crowns replaced, active periodontal lesions treated and all endodontic therapy completed.
Muscle and Joint Pain
Many divers experience headache and facial muscle pain from the continuous jaw clenching that is required to maintain the mouthpiece of the regulator in proper position. The typical mouthpiece is made of neoprene or silicon rubber and is held in place by bite tabs that fit into the dentition of the canines and bicuspids. The average dive is 40-60 minutes and requires rather constant pressure on the jaw muscles, resulting in fatigue if not pain. Those individuals with “TMJ syndrome”, (painful temperomandibular joints), find this to be so painful as to preclude diving at all.
Extending the bite tabs to cover the molar areas balances the weight of the regulator and relieves the stress on the joint.
There is a commercially available mouthpiece developed by an Orthodontist, Dr. Randall Moles, known as “SeaCure” that is heat moldable and covers the posterior teeth. This is available through dive shops for about $30.
The Edentulous and Partially Edentulous Diver
One should avoid wearing full or partial dental prostheses while diving as they can be dislodged and aspirated easily, especially partial dentures. To completely eliminate the possibility of dislodgment, a custom mouthpiece must be made., using a silicon rubber mouthpiece (“Comfo-Bite” from U.S.Divers) for the impression. Full arch impressions are taken with the patient holding the putty in the roof of the mouth until it is set, then mounted in a hinge articulator and sent to the lab with the silicon putty impression. This custom made edentulous mouthpiece will allow the diver to participate with no chance of aspiration of a dental prosthesis.
Dry Socket and Diving
A “dry socket” occurs when the blood clot is lost from an extraction site prematurely, exposing the underlying bone and fine nerve endings. The loss of the blood clot also allows continued bleeding and retards the healing process. The situation is very painful but essentially harmless, usually responding to impregnated gauze packs every 2-3 days over a two week period. Subsequent formation of new clot allows for eventual healing to take place, usually in about two months. Rinsing with non-alcoholic fluids twice a day for two weeks after impacted mandibular third molar removal significantly reduces the incidence of alveolar osteitis or dry socket.
Dry socket occurs in about 5% of tooth extractions, but in 33% of extractions in women on oral birth control pills, when the extraction is in the first 3 weeks of the cycle. In addition, there are some activities which may increase the propensity for dry socket formation… smoking, drinking carbonated beverages in the first 24 hours after surgery, spitting or drinking through a straw in that same time period. This latter Venturi effect of clot removal might also come into play with divers sucking air through a snorkel or regulator. Loculated air pockets do not seem to be an important factor, as is the case with an incomplete root canal
With the information above, one would suppose that a diver could return to the sport anytime between two and eight weeks – depending upon the rate of healing, lack of infection and absence of pain as determined by his/her oral surgeon.
Root Canal and Diving
by Larry Stein, DDS
A root canal treatment involves the removal of the nerve tissue from within the offending tooth. Many patients think that roots are being removed which is not true.
If you have an infected tooth or the dentist finds pus (infected material) inside the nerve chamber and canals, he may perform the procedure in stages–usually 2 visits. In the last few years it has become customary to try to finish a root canal in 1 visit, time permitting, if the tooth is NOT infected. Not infected does not mean you don’t have pain.
Most root canal procedures don’t hurt–during the procedure or afterwards. HOWEVER, there are a few cases that create the fearful reaction of patients when they hear that they need this treatment.
Following the root canal, most root canal specialists (Endodontists) will place a cotton pellet and a temporary filling into the pulp chamber. This is done whether the canal is treated in one or more visits. The tooth should then have a post, core and a cap as a final restoration. Minimally, the canal and chamber must be closed airtight with either a permanent cement, or a permanent filling. No cotton should be left in the chamber and no airspace should remain.
A cement filling or a permanent filling should only be considered temporary. If no cotton is placed and a TEMPORARY filling is used, it will leak. Leakage from the mouth into the root canal space is one of the leading causes for root canal failure. A temporary crown place over a core or post and core should cause no problem but in the week or two after the crown preparation, while you are waiting for the permanent crown, sometimes the temporary crown comes off. Don’t lose it–put it back on and get back to your dentist.
There is one exception to the diving with a temporary cap rule. If your restorative dentist has prepared the tooth for a cementable, metal post and core which will be placed at the time the crown is cemented, then THERE WILL BE AN AIR SPACE WITHIN THE TOOTH. In this case it is possible for the tooth to implode. So ask the endodontist to place a core or your restorative dentist to place a core at the time of crown preparation. No air space, no problem.
Some teeth in need of root canal therapy are fractured. The fracture cannot be seen on an X-ray. The fractured portion of the tooth can constitute a potential site for compressed gas to accumulate. Root canal teeth are also more brittle than vital teeth and can be broken more easily–that is the reason for the cap recommendation.
Finally, you should expect 1-2 visits to the specialist and 2 visits to the restorative dentist. If the root canal procedure is multi-visit then wait until it is completed and has a solid core inside. Your pool classes
shouldn’t be a problem but any open water dive could be. Stay away from the deep end of the pool if the root canal is not complete.
The actual root canals are filled with a material called gutta percha. It is a rubbery like substance which flows under heat and pressure. It is compressed into the canals just to the narrowest part of the nerve canal(s). Filling a canal short may leave room for debris, dead tissue and bacteria to accumulate. This may lead to a future retreatment. It is also a potential area for compressed gases from the bloodstream to accumulate. Since there is no active blood supply to the area short of a complete fill, the accumulated
gases will expand on ascent and cause pain.
In fairness to dentists who perform root canal treatments, it can be difficult to see the actual end of the canal. Some specialists now have operating microscopes and fiber optic devices they can thread into the canals and actually see the end of the root from within. This is now becomming the “Standard of Care”. I would suggest a specialist with fiber optic instruments and microscopes–especially if the tooth is a molar. Recent research has shown that nearly 30% of molars may have an extra canal that escapes detection visually. That untreated canal can be a cause for future failure of the tooth.
Larry Stein, DDS
Consultant to Diving Medicine Online
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*Some material adapted from William E. Stein D.D.S., Aitkin, Minnesota.