Dentistry
Dentistry (click
on a topic): Introduction
Tooth Decay: Signs and symptoms
, Treatment Gingivitis
: Treatment of gingivitis
Introduction Dental
disease is potentially life threatening as a defect in a tooth from a dental cavity
or from periodontal disease or from neglected decay (caries) can lead to tooth
infections that worm their way into the blood stream and can lead to dental abscesses
and to sepsis. In people with heart valve problems this can lead to bacterial
endocarditis, which has the potential to become a life threatening infectious
condition. When people are in their thirties or forties, it is not uncommon to
develop the first root canal problem. When a cavity gets deep enough to affect
the blood supply of the nerve that supplies the tooth with sensory fibers, the
nerve dies off and the person may not feel that there is anything wrong with the
tooth unless it is checked out by a dentist. Eventually the deeper nerve fibers
or the neighboring nerves of the adjacent teeth get irritated and the patient
feels a deep gnawing pain. This is when the patient is usually seen by the dentist
and a root canal followed by a crown is often required. Before a number of common
dental conditions are described in more detail, here is a brief description of
the anatomy of a tooth.
A tooth has a crown and a root. The crown is coated with a very hard enamel layer
and is what we see when a person smiles. The root is buried in the mandibular
or maxillary bone, which gives the tooth a very solid footing. The pulp chamber
is surrounded by a hard, but porous dentin layer, which is coated with enamel
on top and with the bone-like cementum over the root. Gingiva is part of the supportive
tissue of the teeth and together with the periodontal ligaments and connective
tissue attaches the teeth firmly within the alveolar bone where the teeth are
anchored. The pulp contains the nerve endings and blood and lymphatic vessels
that enter the pulp cavity through the root canal. The other important ingredient
in the oral cavity is the constant secretion from the salivary glands that bathe
the teeth in saliva and keep the bacterial flora diluted. The tongue with its
very sensitive nerve endings helps to spot remaining food particles on top and
between the teeth, which helps to clean and protect the teeth from decay.
Tooth Decay Tooth decay occurs mostly
on top of the enamel coating, which can occur in the crown of any tooth. In elderly
persons where there is less saliva for protection and the root is more exposed
because of gingiva retraction, severe tooth decay at the root level can cause
the loss of several teeth. As early tooth decay, called caries, is painless in
the first few months, the only rational approach is to have regular check-ups
with the dentist every 6 months. The dentist will use a sharp instrument to probe
for soft spots in the enamel. These usually start around micro fissures in the
tooth that can extend down to the dentin level. Other tests such as X-rays will
also show the extent of the tooth decay. When dental cleaning has not been done
every 6 months, a thin coat of plaque from old decayed food and bacteria is on
top of the enamel. The bacteria produce acids that burn holes into the enamel.
Mutans streptococci with varies subspecies specialize in growing in plaque. Cola
drinks with phosphoric acid, sugar and other sweets that feed the mutans bacteria
all contribute to the tooth decay process.
Signs and symptoms Sometimes there
is a discoloration of the enamel, but as long as the tooth decay involves only
the enamel layer, there is no pain. Pain starts when the cavity invades the dentin
level of the tooth. Sensitivity with cold and hot foods and beverages indicates
that there is a defect in the enamel that reaches down to the dentin level. This
is a late sign telling the patient to quickly see a dentist. If this does not
happen, chewing becomes painful as well and the patient may awake in the middle
of the night with a tooth ache. As the dentin is porous, bacteria find it easy
to invade into the pulp cavity leading to a pulpitis and root canal infection.
Treatment The
dentist needs to assess the depth of the tooth decay and remove anything that
is decayed. This is done by drilling. More severe cavities need to be X-rayed
to determine the depth of the decay. If the pulp has been affected, a root canal
treatment with a crown is the treatment of choice. If the decay involves only
the superficial enamel, a filling will preserve the tooth with its root intact.
There has been a heated debated about the use of silver amalgam, which contains
silver, mercury, tin, copper, zinc and other traces. Over the years this has been
providing fillings that lasted on average of 14 to 15 years. Newer materials have
been developed and are now very popular because of the fear of systemic mercury
blood poisoning. For those of you who may be skeptical about the effects
of mercury from fillings, here is a You tube link to convince you otherwise.
Mercury poisoning has been first detected in children with autism, but lately
more and more evidence has accumulated regarding Parkinson's disease and Alzheimer's
disease as neurological disorders that can be directly linked to mercury fillings
(the more fillings, the more severe the disease). Composite resins that
have a more pleasing appearance and have been used in the past for repairs of
the visible front teeth, are now used more and more for molar teeth, even though
they last only half as long as the traditional silver/mercury amalgam fillings.
Newer porcelain or ceramic inlays are now being used as well, but it is not known
yet how long these will last. The "gold standard" is the use of gold
inlays and gold crowns as they last 30 to 40 years. However, this needs to be
combined with an aggressive prevention program consisting of dental cleaning and
fluoride treatment every 6 months and daily brushing with a soft tooth brush after
every meal and flossing once every 24 hours. Flossing prevents gingivitis and
periodontal disease. It takes only 24 hours for soft tartar to form (=plaque)
and within a few days this gets calcified and becomes hard plaque that will not
be removed with regular brushing. Personally, I would recommend that you ask your
dentist to replace all silver amalgam fillings (they contain mercury) with these
latter materials.
Gingivitis The middle third of the
tooth is imbedded in gingiva. Without flossing the gingiva forms pockets that
are colonized with the acid forming bacteria (mutans streptococci mentioned under
tooth decay above). This leads to a pH of less than 5.5 and subsequent decalcification
of enamel and cementum where the gingiva has retreated and the neck of the teeth
has been exposed. The next step is tooth decay and cavity formation. Chronically
inflamed gingiva is called gingivitis, a painful gum disease, which can cause
bleeding after minor mechanical impact such as chewing food. A lack of dental
hygiene (not brushing, not flossing) leads to gingival pockets harboring even
more bacteria and accelerating tooth decay. Gingivitis
occurs commonly also during puberty, during menstruation, pregnancy and if a patient
is on the birth control pill. Some medical conditions such as diabetes and AIDS
are known to be associated with a higher incidence of gingivitis as are severe
vitamin C and niacin deficiency. Patients with Crohn’s disease also are more
susceptible to develop gingivitis. A severe form of acute necrotizing ulcerative
gingivitis is also called a “trench mouth” or “Vincent’s infection or
angina”. This can occur in smokers or debilitated persons under extreme stress.
Other contributing factors are poor oral hygiene, sleep deprivation and nutritional
deficiency.
Treatment of gingivitis Gingivitis
can be almost completely prevented by regular dental hygiene consisting of regular
tooth brushing and flossing. By removing plaque every 6 month (in high risk conditions
mentioned above more often, perhaps up to 4 times per year) the mouth flora changes
into a more caries resistant flora with much less likelihood of gingivitis developing.
The dentist may decide to intervene with minor surgery, if the pockets have an
excessive depth, severe infection or abscess formation. More severe cases may
need antibiotics and debridement by a dentist or oral surgeon.
Periodontitis When gingivitis is
worsening, it can affect the periodontal support tissues, the gingiva, the alveolar
bone, the periodontal ligament and the cementum layer. When these structures are
inflamed, periodontitis has begun. Without acute intervention with the help of
a dentist this leads to chronic periodontitis. Often this develops in patients
with chronic diseases such as Crohn’s disease, diabetes, immune deficiencies,
connective tissue weaknesses like Ehlers-Danlos syndrome and others. HIV associated
periodontitis is particularly aggressive and requires close attention and treatment.
This is similar to acute necrotizing ulcerative gingivitis, but with this progressive
periodontitis 9 to 12 mm of attachment of gingiva to the teeth gets lost in only
6 months. This allows mouth bacteria and pathological bacteria to cause accelerated
decay of the roots.
Signs and symptoms There is surprisingly
little in terms of symptoms. However, with meals the periodontal pockets cause
pain and trigger a check-up with the dentist who readily diagnosis periodontal
disease as there are pockets of more than 4 mm depth. Dental X-rays show loss
of alveolar bone.
Treatment of periodontitis Periodontal
disease is treated by close follow-up with the dentist. Initially the patient
may have to be seen every two weeks with increasing intervals between visits when
the condition improves. In the beginning the dentist will do scaling and root
planning. This consists of removing diseased dentin. The root needs to be smoothened
to make it difficult for pathological acid producing bacteria to grow. Plaque
and calcium deposits are removed; any defects have to be restored. The patient
supplements this periodontal disease treatment program by doing frequent tooth
brushings at home with a soft tooth brush and by flossing. When the pockets remain
less than 4 mm, the only maintenance treatments required are regular cleanings
by the dentist. If deeper pockets persist, a more vigorous treatment program is
utilized involving antibiotics and periodontal surgery. Occasionally pocket reduction
surgery and tooth splinting for loose teeth are required.
Pulpitis and Root Canal Infection Pulpitis
is an inflammation of the dental pulp that develops when tooth decay (caries)
is left untreated. It can also follow untreated trauma to a tooth or after extensive
restorative work has been done for tooth decay. When a cavity reaches deep into
the dentin layer of the tooth or when trauma affects the lymphatic flow or the
blood vessels within the root and the pulp of the tooth, pulpitis develops as
a reversible condition. When the cavity is repaired by the dentist, the inflammation
of the pulp often subsides and the tooth may survive unharmed. If the swelling
inside the rigid dentin layer is not subsiding, the circulation through the narrow
root canal comes to a stop and the pulp inside the tooth dies off. This is known
as irreversible pulpitis and is very susceptible to infection. Dental x-rays help
the dentist to assess the extent of the tooth
decay and whether or not the alveolar bone has been eroded.
Signs and symptoms With reversible
pulpitis there is hypersensitivity to cold food products or to sweets. When the
stimulus is removed by rinsing out the mouth cavity, the pain is gone within 1
to 2 seconds. With irreversible pulpitis the condition is much more difficult
to pinpoint as the symptoms are more subtle and confusing. First, there is often
a spontaneous onset of pain, but the tooth ache is less well localized. If there
is aggravation by cold or hot food, this lingers on for much longer, even when
the stimulus is removed. The patient has sometimes difficulties to localize the
root canal pain as it is more diffuse in nature and the tooth pain may even switch
between the upper and lower teeth, which are either supplied by the maxillary
nerve or the mandibular nerve. Interestingly, there is never confusion between
right and left. When the nerve is dead, the pain can disappear for a few days,
but new pain symptoms arise as complications of super infection set in. As the
infection spreads through the apical foramen from inside the tooth to the apex
of the tooth, the whole tooth gets lifted from the tooth abscess, which is sensed
by the patient as the tooth being “too high” and being painful with every
bite. This is an emergency and requires intervention by the dentist. At this late
stage the tooth may need to be extracted. If this condition is left untreated
this can lead to cellulitis, osteomyelitis, parapharyngeal abscess, mediastinitis,
pericarditis and even to a brain abscess or to sepsis.
Treatment As already discussed, treatment
for reversible pulpitis consists of a repair of the cavity and tooth restoration.
With irreversible pulpitis root
canal treatment (endodontic treatment) is required. This involves the
reaming out of the dead pulp including the root canal nerves. Next the root canal
is filled with a rubber like substance, called gutta percha, and the tooth is
topped with a crown (out of gold or porcelain). When all is done, the patient
should no longer have pain and x-rays a few months later would show that all of
the radiolucency of the apical bone has normalized.
Tooth Fracture The severity of a
fractured tooth can vary from a crack in the crown to a crack lengthwise in the
entire tooth (split tooth) to a broken off tooth. A bad habit of grinding the
teeth (bruxism) predisposes the person to tooth fractures. If the patient is able
to present with the avulsed tooth within an hour of the accident, the dentist
may be able to re-implant the tooth. However, the tooth should be kept moist in
milk (or 0.9% saline solution) without manipulations of the root where the vital
periodontal ligament remnants will help increase the chance of tooth survival
when re-implanted. Antibiotics are usually also given for a period of time.
Abscessed Tooth and Tooth Infection Even
though a tooth abscess often comes on suddenly and leads to a tooth pain that
is unbearable, there is usually a long history of neglect of dental hygiene and
a lack of regular check-ups with the dentist, which eventually leads to this dental
emergency. This can come from a crack in the crown of a tooth that allows infection
to go into the pulp and the root of the tooth. Any defect in the dentin encasing
of the pulp and the root canal will allow mouth bacteria to cause an infection
of the pulp and the apex of the tooth (located at the bottom of the tooth).
Symptoms This leads to swelling of
the gum tissue around the abscessed tooth. There may be a foul odor, throbbing
pain and pain with chewing. Hot or cold food items will make the pain worse and
the pain will linger on even later. There can also be a fever and the regional
lymph glands may be swollen. The dentist confirms the presence of an abscessed
tooth by inspecting, palpating and tapping. An x-ray confirms the abscess at the
bottom (apex) of the tooth.
Treatment Antibiotics and pain medication
is given initially. If the abscess is too far gone, the dentist will have to do
a tooth extraction. However, if the tooth can be preserved, the cause of the infection
has to be identified and treated. This could have come from a defective filling
with further tooth decay or from a crack in the crown of the tooth from grinding
the teeth. At any rate, the infected pulp and nerve in the root canal has to be
removed as described under “pulpitis and root canal infection”. After the
systemic infection has been cleared, the dentist likely will suggest attaching
a crown of gold or porcelain to add stability to the top of the tooth. More
info on abscessed tooth
Bruxism Clenching or grinding of teeth
is medically called “bruxism”. It leads to grinding down of the enamel of
the crowns of the opposing teeth. Often grinding of teeth is done while the person
is asleep at night. If left alone, there can be micro cracks in the enamel and
cavities that can cause infection of the pulp and lead to tooth loss. The support
tissues in the periodontal area can also be damaged leading to loose teeth. Tense
people who may have obsessive compulsive disorders, anxiety disorders and other
psychological or psychiatric problems would be at a higher risk of developing
bruxism. Treatment Bruxism
is treated by concentrating on not grinding the teeth during waking hours. This
will spill over to a certain extent into the nighttime hours. If not, a bruxism
guard at night may have to be worn, which are available over the counter in drug
stores and some sporting goods stores. Occasionally anxiolytics can be prescribed
for a short period of time, but on the long term this is not acceptable as they
are addicting.
Temporomandibular Disorder (TMJ disorder) The
temporomandibular joint (TMJ) is a joint between the jaw and the temporal bone
of the skull. As this image shows the mandibular condyle does not articulate directly
with the glenoid fossa of the temporal bone, but there is a donut like disc or
meniscus in between, which separates the TMJ
into an upper and lower joint component. Several conditions can cause jaw
pain (TMJ pain) such as osteoarthritis, rheumatoid arthritis, infectious arthritis
and several other medical conditions. Usually TMJ
pain or dysfunction is associated with pain centered around the TM joint
and in the teeth. But this image shows that it tends to radiate into the adjacent
areas of the head and neck. It tends to be multifactorial. There are dentists
who specialize in this very complicated field. The patient would be advised to
see one of these specialists, if the dentist has no readily available answers.
A myofascial pain syndrome can develop out of TMJ dysfunction, if it is not treated.
Symptoms There
is tenderness just below the external ear canal on the affected side. In pronounced
cases the jaw may move to the affected side when the mouth is opened. There may
be clicking and sometimes catching in the affected jaw joint. The patient may
get muscle spasm in the night from nocturnal bruxism. Myofascial pain syndrome
can occur in patients with normal temporomandibular joints. This syndrome is more
common in women that in men and has a peak in women ion their early 20s and again
around the time of menopause. More info: Temporomandibular
joint pain
Tooth Whitening and Cosmetic Surgery There
is a branch of dentistry that deals with cosmetic issues. Teeth are very visible
when a person smiles (particularly the front teeth). There can be gaps between
the teeth that are genetically determined. Other factors are from lifestyles such
as smoking that is one of the most common causes of discoloration of the enamel
of teeth. But aging and exposure to food pigments also leads to a yellowing of
teeth. In children whose mothers were exposed to tetracycline during the tooth
forming period in their pregnancy will have darkened teeth in the first set of
teeth until the age of 9 years. It is rare that the permanent teeth are affected.
What are the methods used?
Tooth whitening This
can be used in the office setting supervised by a dentist or at home by home treatment.
Not every person is a candidate for this and if you can afford the cost, the professional
approach may be best for you. Both approaches are very effective and are about
equal in the final result. If you had a lot of dental work done with different
types of fillings, the dentist supervised whitening may be best for you or the
dentist may advise that you are not a candidate at all. Keep in mind that any
dental work including crowns, fillings or repairs with porcelain, amalgam etc.
will not whiten. You may end up looking spotty as the normal enamel will whiten
but the previous dental work will stay with its color shade. A dentist will whiten
your teeth for upward of 1000$. The dentist uses 15 to 35 percent hydrogen peroxide
gels and combines this usually with high intensity light to expedite the bleaching
process. On the other hand the home whitening kits range between 10$ and 35$ per
kit. The over the counter preparations contain 10% of carbamide or hydrogen peroxide.
Carbamide breaks down in the mouth into hydrogen peroxide and urea, so essentially
all of the whitening action comes from the hydrogen peroxide. The stains from
smoking, from consumption of stained foods like red wine, black tea, coffee etc.
or some of the yellowing from aging will be bleached by putting the shine back
on the enamel crystals. Regardless of the method employed of the tooth whitening,
the effect will lasts for about 5 years. Long term studies have shown that the
home bleaching method using 10% of carbamide or hydrogen peroxide is the safest
method causing no harm to the enamel of the tooth. The more concentrated bleaching
in the dentist’s office can lead to porous enamel, which may cause dental decay
down the road, and it also tends to irritate the gums more. The dentist can counteract
the gum irritation with fluoride additions. Other products are whitening strips,
which are very effective and whitening toothpaste, which is about moderately effective.
Paint-on whitening, which consists of titanium dioxide is not very effective and
you may perhaps consider this a waste of your money.
Cosmetic Dentistry Some people were
born with less attractive looking teeth than others. There may be unsightly irregular
gaps between the front teeth or partially rotated teeth. Whitening will not take
care of these structural changes, but they often affect the owner’s emotional
wellbeing significantly. The cosmetic dentist can make a difference here. This
has been well publicized in TV series as “extreme makeovers”. No wonder, as
the difference between before and after tooth appearances can be as impressive
as a facelift! Porcelain veneers are the most popular ones of the cosmetic dentistry
procedures. If teeth are discolored or stained or if there are unequal gaps, these
can all be remedied with this procedure. It consists of porcelain wafers that
are custom-made and fitted usually for the upper six teeth. They are matched in
color and shape to the lower front teeth. The dentist removes the upper enamel
layer of the teeth to be veneered. Within two weeks during which the patient wears
temporary veneers, the custom made veneers are ready to be placed permanently.
The cost per veneer application is about 500 to 900 dollars per tooth, so for
six teeth the bill could be 3000$ to 5400$.
Tooth shaping When there are minor
inequalities of height of neighboring teeth, this can be equalized by shaving
a small amount of enamel off the tooth that is too long. This is tolerated well
and only rarely leads to a slight hypersensitive for a period of time, but this
responds to prescription strength fluoride for a period of time. The cost per
tooth is about 30$ to 80$.
Tooth colored fillings There is more
demand now than in the past for tooth colored fillings. Technically this has become
possible as resin fillings now last a lot longer than in the past. It is particularly
useful in front teeth because of the appearance that blends into the natural tooth
color and because the pressures on a front tooth are not as high as on molars.
However, even in the back teeth resin fillings can be used for a period of time
until a porcelain crown is needed. Resin fillings are about 100$ to 400$ per tooth
and last about 5 to 7 years. They can be put in place within one hour (during
the same visit when the defect was assessed). Porcelain crowns likely last 15
years, but are a lot more costly.
Resin-bonded bridge When there is
a missing tooth in the front row of teeth, a resin-bonded bridge may be the solution.
Here is a link that shows that the gap can be filled in with an artificial tooth
made of resin or porcelain and attached to the neighboring teeth from behind with
wings out of metal or resin. This dental bridge works well for front teeth where
the pressures are less than for back teeth where the forces from biting are too
high, so that there a regular dental bridge would be required. A resin bonded
bridge is about 1000$, a regular bridge about 2000$ to 3000$ and a tooth implant
about 3000$ to 3500$. Illustration
of bridge |
