Avoid snacking and sweet and acidic products, brush your teeth after each meal… Even with good dental hygiene which limits dental plaque, rare are those who will never have cavities… It is also one of the ten most common chronic diseases. To treat it, the tissue affected by the bacteria is first removed, then the hole is filled in to restore the shape and function of the tooth. Depending on the size and location of the cavity, different solutions can be proposed. The choice will be made according to the quality of the filling, the durability, the aesthetics, and of course the cost and reimbursement, which vary greatly from one method to another.
Small cavity on molar: composite… or amalgam
First reserved for the front teeth, these enamel-colored composite resins are increasingly used for the posterior teeth. This paste based on particles of quartz, silica and zirconium, adapts perfectly to the cavity to be filled. “The new composites are more resistant, however they sometimes age badly and can be infiltrated and change color”, observes the surgeon-dentist Frank Amoyel. Charged at a minimum of €30.77, they are only covered by Medicare on the basis of 70% of €16.87.
Some dentists still use gray amalgam. Inexpensive (listed at €16.87 by health insurance, it is covered at 70%), it is implicated because it contains mercury, which is potentially harmful.
Should we be wary of mercury fillings?
The amalgam, also called “filling”, is composed of an alloy of silver, tin, copper and zinc associated with mercury mixed to produce a gray paste. It has the advantage of being very resistant and of having anti-caries properties. The mercury it contains would be potentially harmful to the body… But the risk threshold is difficult to assess. As a precaution, it should not be used in the pregnant woman or breastfeeding and in people sensitive or allergic to any of its components, nor near other metal fillings or crowns to avoid electrochemical corrosion. “I no longer place amalgam fillings, but I do not remove those that are in place, unless they are damaged”, specifies Dr Franck Amoyel. It is especially during the break and the removal that the mercury dust is diffused.
Large cavity on molar: inlay or onlay
When the hole is more important (recurrence of decay, etc.), the dentist can reconstruct the tooth using a small ceramic or metal composite block, made to measure in the laboratory, then glued or sealed. This requires an impression and two sessions. The inlay is a small piece that is embedded. The onlay is a “partial crown”. It is used when it is necessary to cover part of the damaged tooth. Reliable and durable, the inlay or onlay remains expensive (400 € on average) and very poorly reimbursed.
Under a crown: new crown or extraction
“Bacteria can sneak into the junction with the gum and cause decay under a crown, most often insensitive since the tooth is devitalized,” warns Dr. Amoyel. It is then necessary to remove the crown to assess the damage, treat the cavity and then put a crown back in place. It may be the same if it is still suitable, otherwise a new one must be installed. If the tooth is too badly affected, we have to extract it. An implant fixed directly in the bone can then replace the root to support a prosthesis. An expensive operation (1,500 to 2,500 €) and not reimbursed.
Caries affecting the nerve: devitalization and crown
When the decay reaches the “nerve” of the tooth, devitalization is necessary. The practitioner removes the pulp, disinfects the root(s), then seals the canal with a waterproof material. Nine times out of ten, the weakened tooth must then be crowned. Metal crowns, in nickel chrome, chrome-cobalt or yellow gold are the least expensive (330 to 500 €). Ceramic crowns on a metal support (500 to 1000 €) or ceramic support (600 to 1200 €), which are more aesthetic, have the same lifespan and minimize the risk of allergy. Medicare only reimburses crowns up to 70% of €107.50.
On a baby tooth: glass ionomer
A recent alternative to composite, glass ionomer cements, which are white-grey in color, continuously release fluoride, which promotes the prevention of cavities. Their lifespan being limited, they are mainly used for deciduous teeth.
A fluoridated toothpaste (dosage < 600 ppm before 6 years, then 1000 to 1500 ppm) helps prevent cavities. In case of high risk, the dentist can prescribe mouthwashes as well as fluoride gels, varnishes or tablets.
On a front tooth: composite and veneer… or crown
When the cavity is small, a composite is used to fill it, which must be replaced after a few years if its color changes. A larger cavity on a living tooth will be filled, then we can carve the tooth to stick a ceramic veneer on it (lifespan 10-12 years, not reimbursed) and find a beautiful smile. When the root is affected, the tooth must be devitalized and the placement of a crown is necessary.
Did you know? We can seal the furrows in prevention
80% of cavities are born at the bottom of the furrows of the upper surfaces of molars and premolars. As soon as the first and second permanent molars come out (around 6 and 12 years old), it is advisable to seal these furrows using a protective fluoride resin. Protection that can be renewed if necessary
Thanks to Dr Franck Amoyel, dental surgeon in Paris, graduate in periodontology, implantology and dental aesthetics
useful addresses
French Dental Association (ADF). www.adf.asso.fr
French union for oral health (UFSBD): www.ufsbd.fr
Cost of treatment on the health insurance website: www.ameli.fr
Or on www.dentalespace.com
Association Non-au-mercure-dentaire: www.non-au-mercure-dentaire.org
>> To read also:
8 natural ways to prevent cavities
Cavities: a third of the world’s population does not treat them
Prehistoric humans already had cavities and dental abscesses