lec 9

Pedodontics

Lec.9 Dr. Sara M. Al-Dabbagh
Fifth stage
Treatment of vital pulp exposures
Injury resulting in an exposure of the pulp in young patients often presents a challenge in diagnosis and treatment even greater than that of pulp exposed by caries. In addition to treating the pulp at the exposure site, the dentist must keep in mind that, as a result of the blow, conditions may be present for many unpredictable reactions in the pulp or supporting tissue. The immediate objective in treatment should be the selection of a procedure designed to maintain the vitality of the pulp whenever possible.
In the management of vital pulp exposure, at least three choices of treatment are available:
Direct pulp capping
Pulpotomy
Pulpectomy with endodontic therapy

Direct pulp capping

The treatment of choice is direct pulp capping if:
The patient is seen within an hour or two after the injury
The vital exposure is small
Sufficient crown remains to retain a temporary restoration to support the capping material and prevent the ingress of oral fluids.
Ca(OH)2 is the material of choice for direct pulp capping. Even though the pulp at the exposure site has been exposed to oral fluids for a period of time, the tooth should be isolated with a rubber dam, and the treatment procedure should be completed in a surgically clean environment.
The healthy pulp may survive and repair small injuries even in the presence of a few bacteria, the same as any other connective tissue. The crown and the area of the actual exposure should be washed free of debris, and the pulp should be kept moist before placement of the pulp capping material.
Numerous pulp capping materials have been studied. Pulp capping with conventional bonding materials is now accepted by many, although the procedure is also considered inadvisable by others. Reports of the use, MTA mineral trioxide aggregate or biodentin or bone morphogenetic proteins not only for pulp capping but also for general use in endodontic therapy for vital and nonvital teeth.
The prime requisite of pulpal healing is an adequate seal against oral fluids. Therefore a restoration should be placed immediately to protect the pulp capping material until the healing process is well advanced. A thin layer of dentin-like material should cover the vital pulp tissue in at least 2 months. If the injured tooth presents a good indication for direct pulp capping, there is a definite advantage in providing this treatment. The pulp will remain functional and reparative, and dentin will develop and allow the tooth to be restored without loss of normal pulp vitality. If final restoration need the use of pulp chamber or the pulp canal for retention, a pulpotomy or pulpectomy is the treatment of choice.


Pulpotomy
If the pulp exposure in a traumatized immature permanent (open apex) tooth is: large (if even a small pulp exposure exits and the patient did not seek treatment until several hours or days after the injury), or if there is insufficient crown remaining to hold a temporary restoration, the immediate treatment of choice is a shallow pulpotomy or a conventional pulpotomy.
A shallow or partial pulpotomy is preferable if coronal pulp inflammation is not widespread and if a deeper access opening is not needed to help retain the coronal restoration.
Pulpotomy is also indicated for immature permanent teeth if necrotic pulp tissue is evident at the exposure site with inflammation of the underlying coronal tissue, but a conventional or cervical pulpotomy would be required. Yet another indication is trauma to a more mature permanent (closed apex) tooth that has caused both a pulp exposure and a root fracture. In addition, a shallow pulpotomy may be the treatment of choice for a complicated fracture of a tooth with a closed apex when definitive treatment can be provided soon after the injury.
The exposure site should be consertively enlarged, and 1 to 2 mm of coronal pulp tissue should be removed for the shallow pulpotomy or all pulp tissue in the pulp chamber should be removed for the conventional pulpotomy. When pulp amputation has been completed to the desired level, the pulp chamber should be thoroughly cleaned with copious irrigation. No visible dentin chips or pulp tissue tags should remain. If the remaining pulp is healthy, hemorrhage will be easy to control with a pledget (a small wad of absorbent cotton) of a moist cotton lightly compressed against the tissue. The pulp should also have a bright reddish-pink color and a concave contour (meniscus). A deeper amputation may be necessary if the health of the pulp is questionable. A dressing of calcium hydroxide is gently applied to the vital pulp tissue so that it is in passive contact with the pulp. The remaining access opening is filled with a hard-setting, biocompatible material with excellent marginal setting capability. The crown may then be restored with a separate bonding procedure.

Pulpectomy with endodontic treatment

One of the most challenging endodontic procedures is the treatment and subsequent filling of the root canal of a tooth with an open apex. The lumen of the root canal of such an immature tooth is largest at the apex and smallest in the cervical area and is often referred to as a blunderbuss canal. Hermetic sealing of the apex with conventional endodontic techniques is usually impossible without apical surgery. This surgical procedure is traumatic for the young child and should be avoided if possible.
In instances of complicated fractures of young permanent teeth with incomplete root growth and a vital pulp, the pulpotomy is the procedure of choice. The successful pulpotomy allows the pulp in the root canal to maintain its vitality and allows the apical portion to continue to develop (apexogenesis).
Occasionally a patient has an acute periapical abscess associated with a traumatized tooth. The trauma may have caused a very small pulp exposure that was overlooked, or the pulp may have been devitalized because of injury or actual severing of apical vessels. A loss of pulp vitality may have caused interrupted growth of the root canal, and the dentist is faced with the task of treating a canal with an open apex. If an abscess is present, it must be treated first. If there is acute pain and evidence of swelling of the soft tissue, drainage through the pulp canal will give the child almost immediate relief. A conventional endodontic access opening should be made in to the pulp chamber.

Therapy to stimulate root growth and apical repair in immature permanent teeth with pulpal necrosis

Apexification

The conventional treatment of pulpless anterior teeth usually requires apical surgery. There is less traumatic endodontic therapy called apexification. Which has been found to be effective in the management of immature, necrotic permanent teeth. The apexification procedure should precede root canal therapy in the management of teeth with irreversibly diseased pulps and open apices. The procedure has been demonstrated to be successful in repeated clinical trials stimulating the process of root end development, which was interrupted by pulpal necrosis, so that it continues to the point of apical closure. Often a calcific bridge develops just coronal to the apex. When closure occurs, or when the calcific plug is observed in the apical portion, routine endodontic procedure may be completed, the possibility of recurrent periapical pathosis is thus prevented.
The apexification procedure recommended to be completed in two appointments. After instrumentation, irrigation, and drying of the canal during the first appointment, sealing a sterile, dry, cotton pallet in the pulp chamber for 1 to 2 weeks. Placing a calcium hydroxide dressing in the canal is optional at the first appointment.
During the second appointment, the debridement procedures are repeated before the canal is filled with a thick paste of calcium hydroxide and camphoric p-monochlorophenoln (CMCP) or calcium hydroxide in a methylcellulose paste, whether the tooth is filled in one or two appointments (or more) should be determined to a large extent by the clinical signs and symptoms present and to a lesser extent by operator convenience. All signs and symptoms of active infection should be eliminated before the canal is filled with the treatment paste. Absence of tenderness to percussion is an especially good sign before the canal is filled. Because of the wide-open access to periapical tissues, it is not always possible to maintain complete dryness in the root canal. If the canal continues to weep but other signs of infection seem to be controlled after two or three appointments, the dentist may elect to proceed with calcium hydroxide paste treatment.
As a general rule, the treatment paste is allowed to remain for 6 months. The root canals is then reopened to determine whether the tooth is ready for a conventional gutta-percha filling, as determined by the presence of a (positive stop) when the apical area is probed with a file. Often there is also radiographic evidence of apical closure.
Four successful results of apexification treatment:
Continued closure of the canal and apex to a normal appearance.
A dome-shaped apical closure with the canal retaining a blunderbuss appearance.
No apparent radiographic change but a positive stop in the apical area.
A positive stop and radiographic evidence of a barrier coronal to the anatomic apex the tooth.
If apical closure has not occurred in 6 months, the root canal is retreated with the calcium hydroxide paste. If weeping in the canal was not controlled before the canal was filled, retreatment is recommended 2 or 3 months after the first treatment.
Ideally, the postoperative radiographs should demonstrate continued apical growth and closure as in normal tooth. However, any of the other three previously described results is considered successful. When closure has been achieved, the canal is filled in the conventional manner with gutta-percha.
Currently, there seems to be a trend away from the incorporation of antibacterial agents, such as CMCP, into the calcium hydroxide treatment paste. It is generally agreed that calcium hydroxide is the major ingredient responsible for stimulating the desired calcific closure of the apical area. Calcium hydroxide is also an antibacterial agent. It may be that CMCP does not enhance the repair on the other hand, it has not been shown to be detrimental. Certainly more than one treatment paste has been employed with success.
MTA or Biodentine can be used to form an apical plug for apexification. The root canals that had suffered premature interruption of root development as a consequence of trauma were rinsed with 5% sodium hypochlorite. Calcium hydroxide was then placed in the canals for 1 week. Following this, the apical portion of the canal (4mm) was filled with MTA, or Biodentin and the remaining portions of the root canals were closed with thermoplastic gutta-percha. At the 6-months and 1-year follow-ups, the clinical and radiographic appearance of the teeth should showed resolution of the periapical lesion. MTA or Biodentine are a valid option for apexification.
Teeth treated by the apexification method are susceptible to fracture because of the brittleness that results from nonvitality and from the relatively thin dentinal walls of the roots. In addition, another important problem with the calcium hydroxide apexification technique is the duration of therapy, which often lasts many months.