Table of Contents
- 1 What is a stainless steel crown?
- 2 Which baby teeth need crowns and which can be safely filled?
- 3 Fluoride and children
- 4 Topical Sealants
- 5 What is a frenum (or frenulum), and why does the dentist want to clip it?
What is a stainless steel crown?
When a back baby tooth is severely effected with decay, but the nerve has not yet been touched, we sometimes place a prefabricated “tin can” which is made out of stainless steel and shaped and sized to fit baby teeth. This allows us to remove just the decay without having to get any closer to the nerve than absolutely necessary. If we can avoid touching the nerve during a restoration, we can usually avoid having to do the pulpotomy described above. These prefab crowns are relatively inexpensive and fairly quick to place, and because of the nature of baby tooth enamel, are more permanent than a regular filling would be. Large fillings in baby teeth do not stand up very well to long term wear. Stainless steel crowns are frequently placed on teeth that have had pulpotomies as well, because by the time a baby tooth needs a pulpotomy, the damage to the crown is so severe that only a stainless steel crown is likely to remain intact for the life of the tooth.
Which baby teeth need crowns and which can be safely filled?
Fillings are adequate for back baby teeth if the decay is not too extensive or too close to the nerve. They are not adequate for teeth which have large or multiple fillings, have decay so close to the nerve that removal of all the decay would expose the nerve, or for any baby tooth in which the nerve has been removed (see pulpotomy).
Stainless steel crowns can be used on virtually any baby tooth, but are best reserved for situations in which the finished filling will take up more than half of the baby tooth, the decay is very close to the nerve, and or if the nerve has been removed. It is possible to place a stainless steel crown over a baby tooth leaving a small amount of decay in place to avoid killing the nerve. The decay generally stops once the crown is placed. Large fillings on baby teeth do not work well because of the nature of the anatomy of the teeth and also because children tend to grind their teeth naturally, and large fillings may not be adequately retained under this type of stress. It is always best to place a stainless steel crown on all baby teeth which have had pulpotomies because these teeth tend to be brittle and are likely to break, especially in childrens’ mouths since they tend to grind their teeth mercilessly.
Although a stainless steel crown can be placed on a back adult tooth as well, we generally avoid doing this because the margins (edges) of the prefabricated crowns do not fit the neck of the tooth tightly, and the result is plaque retention and gum irritation leading to periodontal destruction (gum disease) around that tooth. Children do not have this problem because of their incredible resistance to disease, and because the baby tooth will fall out naturally before the child is old enough to develop the problem. For more on prefabricated crowns and adult teeth click here.
I have written an three pages on the advantages, disadvantages and controversy surrounding fluoride (along with a rather amusing letter from an antifluoridationist). In general, fluoride is a well accepted fact of life in American dentistry. We use it in toothpastes, mouth rinses, topical applications, for desensitizing teeth, remineralizing decay, and as a dietary supplement for children.
Topically applied fluoride creates a coating of decay resistant armor which lasts for several days on the surface of the teeth, and penetrates into decayed areas of teeth to help remineralize them. (Fluoride binds with decayed tooth structure and encourages it to recombine with calcium in the saliva to begin the process of hardening the decay
.) We recommend it in all the toothpaste you buy so everyone in the family can enjoy this protection.
We also recommend that children under the age of 12 receive daily doses of fluoride in tablet form, or in the municipal water supply. This form of fluoride is incorporated into the actual structure of the teeth that are developing at that time, and imparts some lifelong protection against decay.
One word of caution however. Very young children often mistake the toothpaste placed on their toothbrushes for candy and will actually eat it. The amount of fluoride in toothpaste vastly exceeds the amount recommended for internal consumption, and the child may get too much of a good thing. Excess fluoride in the diet of children with developing teeth can cause fluorosis of the teeth. This causes orange, brown and white spots in the enamel of the adult teeth which are forming at the time of the overdose. We recommend that you supervise the use of fluoride containing toothpastes by young children, or that they use non fluoride containing toothpaste until they are old enough to understand that toothpaste is not candy.
When children come in for an exam and cleaning, it is routine for us to use a fluoride tray application which contains prescription strength fluoride for longer lasting protection, and in order to help stop decay already present. Adults do not receive this service even though it would benefit them also. The reluctance of the profession to provide fluoride treatments to adults probably stems mostly from the perception by the general public that fluoride is only for children.
Adult molars (the large back teeth), as everyone knows, have deep grooves on their biting surfaces. Because of their depth, sticky sweet foods like raisins, fruit rollups and of course candy may get stuck in them and remains there for 30 or 40 minutes after the treat is finished. The enamel at the bottom of these grooves also tends to be very thin. Thus, they are often the first places decay forms in the teeth. For many years, before the advent of fluoride as a public health measure, many people lost their back teeth before they reached adulthood simply because these grooves were so susceptible to decay. Even after the widespread use of fluoride in drinking water became common, the top surfaces of the back teeth tended to get decay and needed fillings.
With the discovery of the process of dental bonding, it became possible to apply a permanent plastic layer to the top of the back teeth to “waterproof” them and seal out germs and sugar. This service became known (appropriately) as dental sealants.
The chewing surfaces of the teeth to be sealed are first cleaned with pumice which looks a bit like fine beach sand. This buffs the surface of the enamel and prepares it for the process of bonding
With the teeth kept dry using cotton rolls, or sometimes a rubber dam, a gel containing dilute phosphoric acid is applied to the buffed biting surface of the tooth. This is allowed to remain on the enamel for about 15 to 30 seconds, and is then washed off. After drying the tooth, the surface looks chalky white which is evidence of the microscopic hills and valleys caused by etching the surface.
The liquid resin (plastic) sealant is applied over the etched enamel. The resin flows into the etched mountains and valleys and then pools in the grooves in the top of the tooth. A bright light is then shined on this liquid plastic, and it hardens into a glass-like coating over the surface of the tooth.
A more up-to-date procedure replaces the resin sealant with a glass ionomer formulation which adheres to the teeth without the phosphoric acid etching technique necessary if the sealant is an acrylic resin or a composite. In addition, glass ionomer has the property of releasing fluoride into the tooth structure, which means that these sealants prevent decay both by preventing sugar and bacteria from making contact with the tooth enamel, and by strengthening the surrounding enamel with fluoride.
I have placed sealants on children’s teeth when they were 12 years old, and many have remained on the teeth as the patient grew into their early 20’s. The success of the sealants depends mostly on the cooperation of the child when the sealants were done.
For a sealant to be successful for a long time, the child MUST be able to understand what the dentist is trying to do and be willing to keep the mouth open and the teeth dry for the duration of the procedure. If the teeth get wet between the time the acid gel is washed off, and the time the final cure is done with the light, the sealant will either not adhere to the etched surface, or may only partially adhere. Sealants fail all the time because they are attempted on children who are too immature to cooperate.
Generally, only adult back teeth are sealed. Baby teeth have enamel which does not etch particularly well, and generally, children under the age of 6 are too young to cooperate in the process. All adult back teeth can benefit. This includes 8 premolars, and 8 molars per patient. Unfortunately, insurance companies frequently will not pay for sealants on premolars. Whether the service is paid by insurance or not, it is still money well spent.
The placement of sealants on the back teeth causes the teeth to bite differently. Children adapt to the new bite with ease, but adults do not. If sealants are placed on an adult’s teeth, that patient will usually begin to grind their teeth together causing headaches, neck aches, ear aches, sore teeth, and teeth sensitive to cold. In short, sealing adult teeth can cause all the symptoms of TMJ. As a rule of thumb, I generally never recommend sealing teeth on anyone over the age of 17 unless they are undergoing adult orthodontics.
The term “frenum” (or frenulum) is from the Latin term which means “little bridle”. It is a small fold of tissue that secures, or restricts the motion of a mobile organ in the body. In the mouth, you can see and feel three of them. One attaches the upper lip to the gums, and if you stick your tongue hard into the fold between your upper lip and the two central incisors, it feels like a tiny tight string stretched between the lip and the gums. Another one is in a similar position between the lower lip and gums, and the third one is under the tongue attaching the underside of the tongue to the floor of the mouth. It is easily seen when you lift your tongue backwards and up to the roof of the mouth. In most cases, these little cords are considered normal anatomy and are simply ignored. Upon occasion, however, these little pieces of tissue can cause problems, in which case they can easily be “snipped” (released) by a dentist without causing any other problems. Their status in the body is a bit like that of the appendix. They are ignored most of the time, but removed when they they cause a problem.
The mandibular labial frenum is the cord between the lower gums and the lower lip. A high attachment of this frenum rarely causes spaces between the lower incisors. It can, however, cause periodontal defects in the adult, and some dentists recommend releasing them in children (about age 9) to avoid this (possible) scenario.
The maxillary labial frenum is the cord between the upper lip and gums. It is often a factor in the formation of a “diastema” between the two front top teeth. A diastema is a space between two teeth, and in most cases, it is an inherited trait.
Traumatic injury to either of these frena frequently happens during a blow to the face. This will usually tear the frenum causing lots of bleeding, but little long term damage. A torn labial frenum is rarely sutured by emergency personnel since it is considered a trivial injury. Unfortunately, torn labial frena are often, but not always associated with child abuse. Regarding abuse, “Current literature does not support the diagnosis of abuse based on a torn labial frenum in isolation. The intra-oral hard and soft tissue should be examined in all suspected abuse cases, and a dental opinion sought where abnormalities are found.”
In little children, the maxillary labial frenum is often attached between the two central teeth. In most cases, this attachment migrates away from the teeth as the child approaches the age of 8 or 9.
Children generally have a large space between their central incisors during the “ugly duckling” years, but by the time the adult canine teeth are fully erupted, between the ages of 11 and 12, the space should close. In some cases, however, the labial frenum retains its high attachment between the teeth, and this can cause the central incisors to permanently retain the space (diastema) between them, as shown in the image above. If this happens, the dentist or orthodontist will often recommend that the child see an oral surgeon to resect (snip) the frenum. This will usually prevent the formation of an adult diastema.
If either parent has a permanent space between his or her front teeth, (in other words, if a space between the front teeth runs in the family), a high frenum that does not regress by age 8 or 9, should be resected to avoid a permanent diastema in the adult.
If neither parent has a space, then they may wish to wait until the child’s adult canines are fully erupted before making the decision. Alternatively, they can have it released just to be safe.
Note: A high frenum that does not cause a permanent diastema may have other negative consequences for the adult. A high frenum in an adult can create a periodontal (gum) defect. This happens because the constant movement of the lip can tug at the gingival attachment to the teeth creating a mechanical defect that can lead to loss of one or both central incisors as the patient ages.
The lingual frenum
The lingual frenum attaches the underside of the tongue to the floor of the mouth.
In most cases, it is long and stretchy enough to allow ample movement of the tongue, but sometimes, it is so short that it binds the tongue firmly to the floor of the mouth causing speech impediments and feeding difficulties in infants. This condition is called ankyloglossia(tongue-tied).
When a dentist discovers this, he or she will generally refer the patient to an oral surgeon to release the frenum. The procedure is known as a lingual frenectomy. This procedure is done at virtually any age. In very young children, it is best performed under general anesthesia. In older patients it is a simple procedure performed using local anesthesia.