This is certainly so with cavities in teeth – they hardly ever go away, if we just wait, even though we might at times be tempted to believe that.

Fortunately most parents of small children are eager to handle any cavities they discover in their children’s teeth. But these teeth are often so small and cavities can not be easily discovered by the naked eye, especially if they develop between teeth – and flossing the teeth of a four-year old is not an easy task.

An additional factor in baby teeth is that cavities can develop rather quickly and virtually undetectable under the enamel. Only when this fragile outer shell collapses do they become obvious.

This might then look like this baby molar…

Decayed Primary Tooth: A cavity in a baby molar will look like this only if it is advanced. At this stage it has probably invaded the nerve (pulp) chamber and is in need of a laser pulpotomy.

If this is a tooth that would fall out very soon it could be removed to save the child from any possible tooth ache, but if this tooth is still needed to keep the space open for the permanent tooth to grow into, it need to be saved. Extracting the tooth and then using a spacer to maintain the opening for the new tooth would probably the more costly and way more inconvenient solution.

If we are in the fortunate situation that the majority of the pulp and nerve are still savable, a pulpotomy can be performed (see the graphical explanation).

The following sequence of images shows how this procedure is performed.

1. Decay has been cleaned out with a slow electric drill. There is bleeding from the gums as well as the nerve, which is exposed.

2. The tooth is sealed from the side with a "matrix" to prevent any blood or saliva creeping into the cavity during the following steps.

3. Laser energy is used to remove the nerve tissue from the pulp chamber (Waterlase at 2.25 W).

4. The laser is angled to completely remove nerve tissue from all the recesses of the chamber, to avoid future re-infection.

5. The openings into the canal are now visible with healthy and untraumatized nerve tissue left intact. Mild bleeding is very normal and indicates healthy tissue.

6. A mild 2-3% hydrogen peroxide solution is used to gently disinfect the chamber and stop bleeding before placing the MTA.

7. MTA (Mineral Trioxide Aggregate), a highly biocompatible cement is used to plug the openings to the canals. Very light pressure with a small cotton pellet is used to compact and dry it to avoid trauma to the nerve.

8. After making sure that there is no bleeding seeping through the MTA, this is now covered with a base of glass-ionomer cement.

9. After the Glass-ionomer sets in 5 minutes, traces of MTA and cement lining the side walls and the margins are removed with a dry, slow bur. A self-etching bonding agent is applied with a micro-brush and dried after 30 seconds.

10. The cavity is now restored with a bonded composite using proper bonding principles.

11. The final filling completed and polished. This tooth will survive for a few years until it is replaced with a permanent premolar.

Tooth ache usually means that the nerves in the center of the tooth – the pulp – are being attacked by an infection. This is mostly caused by a cavity that remained too long untreated so that it penetrated the enamel, the underlying dentin and is now approaching the pulp.

The following illustrations show the progression and treatment of this condition.

Nerve dying: A cavity arising in a tooth, if not addressed in time, will eventually approach the nerve (pulp) and cause an infection. At some point the infection will irreversibly damage the nerve and cause it to die. Usual symptoms characterizing this stage are pain, pain to hot drinks and throbbing.

1. The necrosis (death) within the nerve chamber will spread to other parts of the root canals. Soon the whole tissue within the nerve chamber and the canals will die and degenerate into pus or a gangrenous mass.

2. The toxic tissue within the canals now spreads out through the small opening at the end of the roots into the bone. A localized bone infection sets in also known as apical periodontitis or local osteomyelitis. The bone at the tip of the roots dissolves away. Symptoms at this stage include throbbing pain and extreme tenderness to touch. Sometimes the tooth feels as if it is longer. This is due to mounting pressure from the pus beneath it that pushes the tooth outwards.

3. Root canal therapy is initiated. An access hole is made and the chamber is drilled out.

4. Special files are used to clean out the canals and widen them. Disinfecting solutions are used to loosen the dead tissue and kill germs. The canals are widened at least four-fold in diameter to make sure all the dead tissue lining the toxic walls, its recesses and irregularities are removed.

5. A laser is used with a special flexible tip to irradiate the canals and further disinfect its walls.

6. After it is disinfected and dried, the canals are filled with a paste that seals the empty space and prevents bacteria from growing.

7. After the paste sets, and commonly in a separate session, the top section of the root canal material is removed, and a space is prepared to accurately accept a fiberglass post. This is bonded inside this space with a resin cement, which also fills the void in the tooth and reconstructs the core for the future restoration. This is called "post and core buildup".

8. The top part of the tooth is now prepared and shaped to accept a porcelain crown or onlay. An impression is taken and the tooth temporized.

9. In the final session, the tooth-colored porcelain is bonded to the tooth. It is important to understand that the tooth is now essentially bonded from the post all the way up to the top restoration, acting as a single unit, as close to an original tooth as one can get. Therefore the stability and function of the tooth is reinforced.

But looking at it a bit closer this perspective does not quite hold true. Although the outer shell seems to be hard as an inanimate object the tooth is a living part of the body. Fact is that the inner parts of the tooth contains living tissue that needs to be nourished to stay healthy. Once the root canal procedure is performed, removing nerve and blood vessels and filling the now empty cavity with an inanimate substance, the tooth indeed becomes an object that is no longer connected to body fluids that make it a functioning part of the body. It has become a dead object that is no longer renewed and protected by the body’s defenses. Bacteria entering through the tiniest cracks might cause persistent infections because there are no blood vessels any longer that would bring white blood cells to fight that infection.

Therefore a root canal should be only a very last resort and every effort should be made to save the inner living part of the tooth – the root canal.

The direct cap procedure is such an effort. The following illustrations by Dr. Sarkissian demonstrate this procedure.

1. HEALTHY TOOTH: A healthy tooth is covered by a shell of enamel, the hardest substance in the body. It is a complex organ comprised of all three embryological layers.

2. CAVITY FORMATION – EARLY STAGE: A cavity starts when bacteria in plaque produce acids which eat away at the surface of the enamel.

3. CAVITY FORMATION – DENTINE INVASION: As the cavity penetrates the softer dentine, it spreads like a wave and infects the microscopic tubes of this live tissue.

4. CAVITY FORMATION – DEEP DECAY: Very soon it approaches the nerve chamber, or the pulp, causing an inflammation which at this stage is reversible. This is when one feels mild pain or heightened sensitivity to sweets and cold.

5. DRILLING OUT GROSS DECAY: Treatment is initiated by removing the outer layers of decay with a slow drill.

6. LASER EXCAVATION AND DECONTAMINATION: The deep layers of decay are removed with the Waterlase® at lower settings, to avoid trauma to the nerve. There is no mechanical insult to the nerve, such as vibration, smearing or heat, which is the case when using drills. The infected dentine is thus removed completely, resulting many times in an exposure of the pulp.

7. EXPOSED PULP: If the nerve (pulp) is still healthy, it may bleed slightly. At this stage the exposure is treated like a wound. It is gently irrigated with hydrogen peroxide, followed with an isotonic homeopathic remedy.

8. DIRECT CAP: The exposure is gently covered with MTA, a cement well known for its biocompatibility and ability to preserve vitality of tissues with which it comes into contact.

9. CORE BUILDUP: The remaining cavity is then lined with a self-priming bonding agent without disturbing the MTA. After drying, the whole dentine surface is built up with a core of a flowable composite or compomer.

10. FINAL RESTORATION: The tooth is restored with an esthetic, tooth-colored bonded restoration, preferably an indirect porcelain inlay or onlay. The biomimetic principle is followed, which means that each part of the tooth that was restored, functionally mimics the biological tissue it is replacing.

The following graphics by Dr. Sarkissian show this development and the treatment of this condition. A permanent tooth would require a root canal treatment at this stage, but for a primary tooth a laser pulpotomy is indicated which keeps the tooth alive.

1. A healthy baby tooth (primary molar). The nerve (pulp) makes up a significant portion of its interior.

2. A true cavity arises when the outer enamel shell of the tooth is penetrated and bacteria invade the interior dentin layer of the tooth.

3. The cavity spreads at a rapid rate.

4. The bacteria have approached the pulp and start causing mild inflammation.

5. Due to softening of the befallen dentin, the outer shell crumbles and exposes the cavity. This is when most parents realize that their child has a cavity.

6. Laser Pulpotomy treatment is initiated. The cavity is excavated with an electric drill.

7. The Waterlase is used to remove, or amputate, the pulp from the chamber. There is no mechanical trauma, heat, or contamination. Hydrokinetic energy is used to break up the tissue without the tearing, crushing and smearing associated with the drill.

8. After mild irrigation with hydrogen peroxide and after bleeding has stopped, MTA (Mineral Trioxide Aggregate) is used to cover and seal the exposed nerves leading into the canals.

9. A glass ionomer cement is used to cover the MTA to allow for undisturbed setting and to prevent its contamination during the multiple bonding steps.

10. The tooth is bonded with resin composite employing the latest techniques in adhesive dentistry.

You can read the article about a real-world pulpotomy to see this procedure performed on a child’s primary molar.

You can find more information on Dr. Sarkissian’s web site under
Services ->Laser Pulpotomy.

There is a common misconception that because of the controversy surrounding root canals, many people avoid treatment of dead teeth despite the fact that these dead nerves act as a mini gangrene made up of the utmost toxic material. These teeth have to be treated at all costs.

Alternative treatment includes extraction of the tooth, which then necessitates the placement of a bridge or an implant to cover the space of the missing tooth and to restore the bite.

Root canal risks:

• Some roots, which are thin, bent, flat, or decayed may be perforated or fractured by the root canal procedure. This compromises the outcome of the treatment and the tooth might need to be extracted.
• Root canalled teeth are more brittle because they are dead and do not receive nutrition from the pulp. This makes them more vulnerable to fractures.
• Vertical fractures may develop in a root canalled tooth due to the propagation of an existing micro-fracture already present in a tooth that has had a previous root canal, due to a post placed to build the tooth up for a crown, or due to a heavy bite.  Because a root canalled tooth is dead, the ligament surrounding it and suspending it in the bone is prone to inflammation, which may cause long-standing tenderness to biting.

Disinfection and canal treatment protocols:

• Laser disinfection by the Waterlase laser
• Ozone injection into the canals
• Irrigation with antiseptic liquids

Materials:  We rarely use gutta percha in our office. The permanent filler materials we use are one of four options (three general and one special):

1. ENDOREZ:  a resin-based material. This material is known to seal the canal systems thoroughly and even bond to the walls with resin tags.
2. ENDOSEQUENCE: A bioceramic material that is also very biocompatible and sets to a hard consistency.
3. MTA: Mineral Trioxide Aggragate is extremely biocompatible, but we only use it for canals that are of certain size and accessibility.
4. ENDOCAL: a calcium-oxide, zinc-oxide based material. Highly biocompatible, and known for diffusing through the canal systems and disinfecting large portions of the root structure. Due to its multiple drawbacks, however, Dr. Sarkissian uses it only in special circumstances, or only for the purpose of medicating the canals for 2-4 weeks prior to being replaced by another material.

Drawbacks of Endocal:  it is not as visible as Gutta percha in x-rays, making it harder to distinguish between filled vs. non-filled portions within the root canal complex.  This means that future dentists may mistake it as an insufficiently filled root canal, and many insurance companies may deny claims for reimbursement. The American Association of Endodontists disapproves of its use due to claims of a higher incidence of root fractures.

We are so used to and are not that much in awe, that we, after the first baby teeth fall out, grow another set of teeth. Usually we just accept as a fact that that is the last set of teeth we ever grow. One characteristic of a good scientist is, that he tries to overcome accepted knowledge, and the fact that we grow two set of teeth and no more, is certainly a challenge for a good scientist.

That is particularly challenging as there are observable facts that bodies are able to repair pretty severe damages. Bones grow together, cuts heal and the lizard can even grow back a whole tail.

As the blue-print for the whole body is contained in every single cell of the body, why stop at two sets of teeth?

Great progress has been made in answering this questions and now researchers were successful in using stem cells to grow a replacement tooth for an adult mouse, the first time scientists have developed a fully functioning three-dimensional organ replacement, according to a report in the Proceedings of the National Academy of Sciences.

The researchers at the Tokyo University of Science created a set of cells that had the genetic instructions to build a tooth re-activated, and then implanted them into the mouse’s empty tooth socket. The tooth grew out of the socket and through the gums, as a natural tooth would. After eleven weeks the engineered tooth had matured. It had a similar shape, hardness and response to pain or stress as a natural tooth, and worked equally well for chewing. The researchers suggested that using similar techniques in humans could restore function to patients with organ failure.

Takashi Tsuji, PhD. Tokyo University of Science A ‘tooth germ’ implanted in a mouse’s jaw grew into a fully functioning tooth with the properties of a natural one.

Chipped teeth are a frequent occurrence, especially among children. They are a cause of serious concern due to their unsightly appearance, as they mainly involve the upper central incisors, the most visible and esthetically important teeth in a person. They play a major role in the self-esteem of a person and even a small chip may alter one’s image.

The fracture can be at varying levels of depth, namely

1. just within enamel,
2. within enamel and dentine, or
3. a deep fracture involving enamel, dentine, with exposure of the nerve.

It’s important to treat fractured teeth as soon as possible, especially those involving the nerve, as any delay will increase the risk for a root canal. Proper bonding techniques can restore a chipped or fractured tooth almost as good as new. If the nerve is exposed, it is treated by laser, decontaminated, capped with a biocompatible cement, and bonded over.

If there is a substantial defect which is hard to restore by direct bonding, a veneer or partial full-ceramic crown may be a better option.

Example 1:

Example 2: