Braz. Endod. J. 1(1):49-51, 1996

Manoel D. SOUSA NETO, Fernando S. CRISCI, Paulo C. SAQUY, Jesus D. PÉCORA

Abstract

The authors describe 2 clinical cases of incomplete root formation associated with trauma, and discuss the role of scheduled periodic changes of intracanal medication in the process of dental apexification.

Key Words: Incomplete root formation, calcium hydroxide, dental trauma.

Introduction

The preservation of teeth with a history of trauma using periodic clinical examination and x-rays is of fundamental importance because several pathological alterations can be diagnosed during the period after trauma.

BAKLAND (1992) reports the following sequelae from pulp trauma which can occur: 1, repair, which is the ideal reaction to an injury; 2, calcification, which can be considered both desirable and undesirable because generally calcification is an attempt of the pulp to respond in a positive manner to an injury; 3, necrosis; 4, reabsorption. These last two are definitely considered undesirable.

Physical trauma occurring with a fall, with or without dental fracture, can cause pulpar hemorrhaging resulting in disturbed nutrition of the cells, hyalinization of the pulp tissue, mineralization and excessive pigmentation of the teeth (ARWILL ET AL., 1967). The pulp can heal completely or necrosis can occur depending on the intensity of the hemorrhaging and the stage of root development or the installation of infection (SELTZER & BENDER, 1979).

Pulp necrosis occurs when the blood flow to the pulp tissue is interrupted, with a subsequent lack of oxygen. In the absence of bacteria, necrosis by coagulation presents a gradual degeneration of the tissues. If necrosis by coagulation has little effect on the periodontal ligament and on the alveolar bone, the tooth can remain completely asymptomatic.

According to ANDREASEN (1984), the conservation of the traumatized tooth ought to always be the objective of the dentist. Besides seeking to maintain the tooth functionally in the alveola, therapy ought to prevent the development of pathologic alterations.

Our objective is to report two clinical cases in which there were later manifestations of dental trauma in the pulp of teeth with incomplete root formation.

Case Report

Case 1

A thirteen year old female was seen at the clinic for routine examination. She reported that she had had a bicycle accident 5 years earlier but had not seen a dentist at that time because there was no apparent damage. A slight alteration in color to gray was observed and vitality pulp tests were negative. Percussion and palpation were normal.

Radiographic examination showed that the right maxillary central incisor had incomplete root formation with the parallel walls of the root canal showing that root formation was interrupted at the time of trauma.

Thus, access surgery and disinfection was carried out. In the treatment of a tooth with pulp necrosis, great care ought to be taken to avoid post-operative complications, principally "flare-up". Dakin’s solution and hydrogen peroxide were used for disinfection.

A paste of calcium hydroxide with iodoform and propylenoglycol was then placed in the root canal using a lentulo. After 7 days, this calcium hydroxide paste was changed monthly for four months and then every 3 months for a period of 9 months, after which apexification was confirmed clinically and radiographically. Obturation was carried out with gutta-percha cones and Grossman cement.

Figure 1. A, Initial x-rayof case 1. B, X-ray showing incomplete root formation with parellel walls. c, Root canal filled with calcium hydroxide paste. D, X-ray 18 months after final obturation.

Case 2

A forty year old female was seen at the clinic complaining of the presence of a fistula in the anterior maxillary region. She reported that she had fallen from a tree while playing when she was about 8 years of age and that she has then lost the left maxillary central incisor. The absence of this tooth was seen clinically and radiographically. Alteration of color of the right maxillary central incisor was observed with the presence of a fistula. The vitality test, palpation and percussion were all negative.

In order to identify the path of the fistula a gutta-percha cone was placed and x-ray examination revealed apical rarefaction and incomplete root formation in the right maxillary central incisor.

Dakin’s solution was used for disinfection alternating with hydrogen peroxide. A calcium hydroxide, iodoform and propylenoglycol paste was placed in the interior of the canal using a lentulo and left for 7 days. Monthly changes of this paste were then carried out for four months, followed by trimestral changes for a period of 9 months when apexification was verified clinically and radiographically. As in case 1, obturation was carried out with gutta-percha cones and Grossman cement.

Figure 2. A, Initial X-ray of case 2. B, Incomplete root formation shown using gutta-percha cone. c, X-ray 3 years after final obturation

Discussion

Daily there is a greater number of individuals who are victims of different types of accidents which can cause often irreversible trauma to dental structures and to their support system, depending on the intensity and form of trauma (PROKOPOWITSCH, 1994).

Injuries which trauma can cause to the dental pulp, such as internal and external reabsorption, necrosis and calcification, have been reported by BAKLAND (1992), showing the importance of preservation using periodic clinical and x-ray exams to detect the presence of these pathological alterations.

Endodontic treatment of teeth with incomplete root formation seeks to obtain physiological complementation of the radicular apex (apexigenesis) or apical closure by means of stimulation (apexification) which is the objective of this report.

Penetrating disinfection ought to be carried out with great care in the treatment of teeth with incomplete root formation with pulpar necrosis because the large lumen of the radicular canal and the thinness of the walls can cause the dental surgeon to fracture the root. In this case, filing ought to be done with only one file, of the greatest caliber, associated with a chemical solution to disinfect the radicular canal. CAMP (1991) reported that the most important factors for apexification are canal cleaning, in other words removal of all necrotic tissue, and the temporary hermetic sealing of the tooth to avoid bacterial infiltration.

Diverse materials have been proposed to induce the apexification of nonvital permanent teeth. MORSE et al. (1990) studied 5 treatment methods for teeth with incomplete root formation and pulpar necrosis and concluded that the success of therapy with apical tissue repair is due to the antibacterial action and the calcification-inducing action of calcium hydroxide.

The biological and bacteriological actions of calcium hydroxide, which was introduced in dentistry by HERMAN in 1920, confirm its preference for intracanal use. Many different substances and vehicles have been combined with the objective of improving the antibacterial action, speed of liberation of calcium and hydroxyl ions, and interfering in the physicochemical properties (FRANK, 1966; LEONARDO ET AL., 1978; HOLLAND ET AL., 1971).

Alkaline paste in combination with other substances or not has the objective of maintaining disinfection of the radicular canal and causing apex formation (apexification). Constant change of the medication maintains the state of disinfection until apexification.

In the cases reported here, the change of the medication in the first four months was carried out monthly and then every three months until a period of twelve months was completed. Change of the paste was initially carried out at shorter intervals due to the rapid reabsorption detected radiographically. The periods of apexification observed in these two cases is in agreement with the literature, which reports that in the absence of infection apexification occurs within 12 to 18 months (HOLLAND ET AL., 1983; ANDREASEN, 1994; TRONSTAD, 1991; ESTRELA, 1994).

The conservation of the traumatized dental element ought to be the objective of our attention, thus the necessity of periodic exams over a long period so that later pathologic alterations can be diagnosed. With this objective, the choice of adequate treatment is of fundamental importance so that the tooth can be maintained in the oral cavity carrying out its esthetic and functional purpose.

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