Q&A With Dr. Houston

Q. How can I fix my crooked teeth and improve my smile?

A: For adults, many options are available including veneers, crowns, bonding and orthodontics (braces or alignment therapy using laboratory fabricated mouth trays like in Invisalign.)

Choosing which one is right for you depends on your time commitment, need for immediate results. Veneers and crowns are finished in 2 treatments over two weeks, while braces and mouth tray therapy usually require 1-3 years of treatment.

If your front teeth already have large fillings or are discolored, veneers, bonding or crowns may be the better choice. For crooked, crowded or rotated teeth without large fillings or discolorations, orthodontic treatment might be a preferable option.

For children, all the adult teeth do not become visible until approximately age 12. Therefore, between the ages of 7 and 10, crowding may become a problem without obvious signs to a parent. This can best be determined by asking your dentist if your child might need braces. Most dentists have enough basic orthodontic knowledge to answer why braces are needed, what is the problem, and what age it should be treated.

An orthodontic assessment should be done for children at the approximate age of 7, and at each regular dental exam and cleaning. Some of the areas to be assessed are the following:

-Deep bites (upper front teeth cover most of lower front teeth)
-Jaw size (growth discrepancies between upper and lower jaws)
-Crossbites (narrow arch or jaw)
-Breathing problems (tonsils and adenoids)
-Future crowding or missing adult teeth
-Protruding front teeth (a distance of 3 mm or greater between the biting edges of upper front teeth and the front surface of the lower teeth)
-Midlines not matched (middle of upper 2 front teeth do not line up with middle of lower 2 front teeth)

Monitoring the growth and development of your child’s teeth and jaw’s will help ensure they can have a great smile!

Q. My Child has bumped their front baby tooth. Will it damage their permanent tooth?

A: In most cases, the adult upper front tooth is well cushioned above and behind the root of the baby tooth. But, if the front surface of the adult tooth is still forming and is bumped by the root of the baby tooth, then the adult tooth may have a dent or discoloration when it erupts and is visible. Repairs can easily be made without requiring freezing using white filling bonding to match the color of the adult tooth.

In cases of more extreme trauma, there is usually more bleeding and a distraught parent. The swelling and bleeding may look bad at first, but the gums and lips are quick to heal. The baby tooth may also be loose, displaced or even completely pushed up into the gums so that it is not visible. This should be determined on an x-ray. Because of the softness of the bone, and small size of the baby tooth, they are more apt to become very loose, as opposed to an adult front tooth which is often chipped or fractured.

The two upper front baby teeth fall out sometime around age 7, so even light trauma to them at age 6-7 years of age, may avulse a baby tooth.

The most important thing a parent can do for kids 5 and younger, is to keep a watch on persistent looseness, pain or darkening of the tooth. If an infection develops inside the tooth, a swelling on the gums may result. This can vary from a small pimple to a larger abscess on the gums just under their upper lip. Since this can develop with or without pain, parents should periodically lift up their child’s upper lip to examine the area. Darkening of the tooth usually happens from a few days to weeks after the initial trauma. This occurs as a result of blood leaking out of damaged blood vessels inside the tooth. If blood is absorbed into the hard tooth structure from within, then discoloration similar to a bruise develops. This discoloration may be a sign that an infection is present or it may be only a result of the blood staining the tooth from inside. A visit to a dentist will allow a more accurate assessment of the trauma and can educate a parent as to whether treatment is indicated. In most cases, reassurance to the parents is all that is needed.

Q. I just had a small filling done and now my tooth hurts. Is this normal? What should I do?

A: The easy answer is to call your dental office and explain exactly what causes the discomfort. Discomfort to biting or cold after a small to medium filling is done may be normal, but it should be addressed if it persists longer than a few days. There are a few reasons why biting might hurt, but are often easy to resolve. The most common reason is simply that the filling was made thicker or higher than the previous tooth structure or older filling . At the end of a filling appointment, the dentist asks the patient to bite on a marking piece of paper that shows if part of the filling is too thick and requires adjustment. However, being numb or open for a long time, can sometimes cause a person to bite incorrectly on the paper and therefore not show the dentist where the filling needs proper adjusting. If the filling is left too high, a person often feels that their bite is different than before the filling was done after the freezing wears off. Normal eating then causes increased forces on that tooth pushing it down into the jaw and inflaming the tooth supporting ligaments and bone. If the person is a night time grinder, bruxer or clencher, they may even be woken up in the middle of the night with a toothache. A visit back to the dental office to recheck the bite and adjust the filling may be all that is needed. If adjustments have not helped after a few days to a week, and the tooth is only sensitive to biting then the problem may be either a cracked tooth or fluid under the filling. The dentist should remove the filling (at no charge) and check for cracks in the tooth that may not have been initially visible during filling placement. This can be done with the use of an intraoral camera and loupes (magnifying lenses on glasses) that give those dentist wearing them a better view of their work. Other ways to check for a crack are with the use of dies and fiber-optic lights to trans-illuminate the tooth. If no cracks are visible, then the dentist should consider that excess fluid under the filling was causing the discomfort (except in very large cavities or removal of big fillings where the nerve may be irreversibly irritated requiring a root canal).

Q. How did I get fluid under my filling?

A: There are a few possibilities. The middle part of the tooth beneath the enamel is called “dentin. It has numerous fluid filled tubules running from the “pulp or nerve” of the tooth out to the enamel. Dentists use local anesthetic to numb the “nerves” of the tooth because any drilling would cause the fluid to move inside the tubules and stimulate the nerve causing pain. If any of this fluid or water from the procedure is not adequately dried on the tooth prior to placing the primer, bonding agent and filling, then it will leave a microscopic layer of fluid under the filling and biting down will cause this fluid to move within the dentin tubules pressing on the nerve and resulting in a sharp pain when biting. Careful attention by the dentist in each step of placing a white filling will prevent formation of this fluid layer.

As a final treatment to reduce inflammation additional laser desensitization therapy can be applied to the tooth and surrounding areas to hasten the healing.

Q. Are there other reasons a tooth might be sensitive to cold or biting?

A: Yes. Here are all the other reasons your dentist might not want to discuss with you. But first you need to understand whether your dentist uses an original 2-step bonding system or the newer 1-step system.

The original 2 step system is actually a 3 step procedure.
An acid “etch” is placed on the tooth for a 15-45 second period, and then rinsed off. The purpose is to create microscopic pore like holes in the enamel and a carpet like surface on the dentin. This is to create an increased surface area for bonding to the tooth.

The second step is to place primer layers on the dentin which “wets” the carpet surface of it making it more receptive to the bond.

The third stage is to place the bonding layer which can be looked at like a liquid glue for the white filling.

Dentists are always concerned about time. The 1-step bonding system is meant to reduce time by putting the acid etch, primer, and bond all in a 1 application procedure. I use the original system because I do not like the idea of an all in one system that leaves an acid on the tooth as opposed to rinsing it off in the 2 step system. It works, but there is a higher incidence of sensitivity with it due to this fact. I liken the primer and bond being put together like an all in one shampoo and conditioner. Adding the acid into the mixture just to save time doesn’t make sense to me as an improvement over the 1-step system.

Was the acid etch rinsed off completely? Acid is an irritant. A long blast of water needs to be used to adequately remove the etch.

If the dentist does not put enough primer layers or bonding layer than the bonding layer may not be able to bond to the dentin properly.

If the liquid bonding layer is too thick, curing of the filling on top of it may cause shrinkage of this bond that pulls it away from the dentin.

White filling material is “cured” with a bright light. If the first layer of a filling is placed too thick before it is cured, then the bottom part of the filling is inadequately bonded to the dentin.

Did the dentist pack the white filling into the tooth adequately, without gaps or voids?

Was there enough water coming out of the drill? As much as a patient may dislike lots of water during “drilling”, it keeps the tooth cool and prevents overheating of the nerve.
You should not “smell” your tooth during drilling.

Did fluid from around the gums or saliva seep under the band around the tooth?
Dentists should use either a rubber dam or adequate cotton barriers to prevent this from occurring.

The air and water come out of the same spray tip. If water comes out of the tip during the drying of the primer or bond, or 1 step system, then the filling will not bond properly.

Didn’t find the answer to your question? Please feel free to email Dr. Houston or call our office at 905-332-5000.