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Restoration of pulpaly involved teeth

الكلية كلية طب الاسنان     القسم التقويم والاطفال وطب الاسنان الوقائي     المرحلة 5
أستاذ المادة حسن فليح فرحان السلطاني       6/3/2011 3:24:00 PM

Lec. 11                                      Pediatric dentistry                                                 د.حسن الوطيفي  

 

RESTORATION OF THE PULPALLY INVOLVED TOOTH
It has been a common practice for some dentists to delay for weeks or months the permanent restoration of a tooth that has undergone vital pulp therapy. The purpose has been to allow time to determine whether the treatment procedure will be successful. However, failures in pulp therapy are usually not evident for many months. Rarely does a failure in pulp therapy or an endodontic procedure on a primary tooth cause the child to experience acute symptoms. Failures are usually evidenced by pathologic root resorption or rarefied areas in the bone and are discovered during regular recall appointments.
Primary and permanent molars that have been treated by the pulpotomy or pulpectomy technique have a weak, unsupported crown that is liable to fracture. Often a failure of the buccal or lingual plate occurs below the gingival attachment or even below the crest of the alveolar bone. This type of fracture makes subsequent restoration of the tooth impractical. Also, a delay in restoring the tooth with a material that will adequately seal the tooth and prevent ingress of oral fluids is one cause for failure of pulp therapy.

Application of a layer of hard-setting cement over the capping material followed by a substantial restoration will adequately protect the pulp against contaminating oral fluids during the healing process. An amalgam restoration, a composite resin restoration, or a glass ionomer restoration may serve as the immediate restoration and often the final restoration for teeth with pulp caps and well-supported crowns. As soon as it is practical, however, other pulpally treated posterior teeth should be prepared for stainless steel or cast crowns. Pulp treatment of a primary molar is often followed by placement of a stainless steel crown restoration during the same appointment.
REACTION OF THE PULP TO VARIOUS CAPPING MATERIALS
ZINC OXIDE-EUGENOL
Before calcium hydroxide came into common use, zinc oxide—eugenol was used more often than any other pulp-capping material. Many dentists have apparently had good clinical results with the use of zinc oxide- eugenol, but it is no longer recommended as a direct pulp-capping material because it may produce chronic inflammation, abscess formation and liquefaction necrosis.
CALCIUM HYDROXIDE
Because of its alkalinity (pH of 12), it is so caustic that when it is placed in contact with vital pulp tissue the reaction produces a superficial necrosis of the pulp. The irritant qualities seem to be related to its ability to stimulate development of a calcified barrier. The superficial necrotic area in the pulp that develops beneath the calcium hydroxide is demarcated from the healthy pulp tissue below by a new, deeply staining zone comprising basophilic elements of the calcium hydroxide dressing. One month after the capping procedure, a calcified bridge is evident radiographically. This bridge continues to increase in thickness during the next 12 months. The pulp tissue beneath the calcified bridge remains vital and is essentially free of inflammatory cells.

PREPARATIONS CONTAINING FORMALIN:
1. Formaldehyde (tricresol formaline).
The clinical success experienced in the treatment of primary pulps with these materials is possibly related to the drug s germicidal action and fixation qualities rather than to its ability to promote healing. Formocresol did not stimulate the healing response of the remaining pulp tissue but rather tended to fix essentially all the remaining tissue.
2. Glutraldehyde.
Glutaraldehyde has received attention as a potential pulp-capping agent for pulpotomy techniques in primary teeth. It is an excellent bactericidal agent and seems to offer some advantages compared with formocresol.
Berson and Good have reported that glutaraldehyde appears to be superior to formaldehyde preparations for pulp therapy in the following ways":
1. Formaldehyde reactions are reversible, but glutaraldehyde reactions are not.
2. Formaldehyde is a small molecule that penetrates the apical foramen, whereas glutaraldehyde is a larger molecule that does not.
3. Formaldehyde requires a long reaction time and an excess of solution to fix tissue, whereas glutaraldehyde fixes tissue instantly and an excess of solution is unnecessary.

Although glutaraldehyde seems to compare favorably with formocresol as a pulp-capping agent, it has not consistently demonstrated significant superior results in clinical trials.

FERRIC SULFATE
More recently, considerable interest and research have been devoted to investigating the effectiveness of ferric sulfate to treat the surface of the remaining pulp tissue after pulpotomy of primary teeth. Ferric sulfate agglutinates blood proteins and controls hemorrhage in the process without clot formation. The main advantage of the ferric sulfate pulpotomy over a pulpectomy when working with children is the considerably faster speed with which a pulpotomy can be performed.

Others:
1. Corticosteroid:
No longer use due to its degenerative effects on the pulp and inhibition of dentionogenesis.
2. Antibiotics:
It used in dentistry with considerable attention because of sensitivity reaction toward certain types of antibiotic.

FAILURES AFTER VITAL PULP THERAPY
Failure in the formation of a calcified bridge across the vital pulp has often been related to:
• The age of the patient.
• Degree of surgical trauma.
• Sealing pressure.
• Improper choice of capping material.
• Low threshold of host resistance.
• Presence of microorganisms with subsequent infection.

Indication of failure after pulp therapy includes:
1. INTERNAL RESORPTION
Radiographic evidence of internal resorption occurring within the pulp canal several months after the pulpotomy procedure is the most frequently seen evidence of an abnormal response in primary teeth. Internal resorption is a destructive process generally believed to be caused by osteoclastic activity, and it may progress slowly or rapidly. Occasionally, secondary repair of the resorbed dentinal area occurs.
Because the roots of primary teeth are undergoing normal physiologic resorption, vascularity of the apical region is increased. Osteoclastic activity is present in the area. This may predispose the tooth to internal resorption when an irritant in the form of a pulp-capping material is placed on the pulp.
2. ALVEOLAR ABSCESS
An alveolar abscess occasionally develops some months after pulp therapy has been completed. The tooth usually remains asymptomatic, and the child is unaware of the infection, which may be present in the bone surrounding the root apices or in the area of the root bifurcation. A fistulous opening may be present, which indicates the chronic condition of the infection. Primary teeth that show evidence of an alveolar abscess should be removed. Permanent teeth that have previously been treated by pulp capping or by pulpotomy and later show evidence of pulpal necrosis and apical infection may be considered for endodontic treatment.

3. EARLY EXFOLIATION OR OVERRETENTION OF PRIMARY TEETH WITH PULP TREATMENTS
Occasionally a pulpally treated tooth previously believed to be successfully managed will loosen and exfoliate (or require extraction) prematurely for no apparent reason. It is believed that such a condition results from low-grade, chronic, asymptomatic, localized infection. Usually, abnormal and incomplete root resorption patterns of the affected teeth are also observed. When this occurs, space management must be considered.
Another sequela requiring close observation is the tendency for primary teeth undergoing successful pulpotomies or pulpectomies to be overretained. This situation may have the untoward result of interfering with the normal eruption of permanent teeth and adversely affecting the developing occlusion. Extraction of the primary tooth is usually sufficient.
Starkey believes that this phenomenon occurs when normal physiologic exfoliation is delayed by the bulky amount of cement contained in the pulp chamber. Even though the material is resorbable, its resorption is slowed significantly when large quantities are present.

 



المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .