Apexification of Blunderbuss Canals with MTA

INTRODUCTION

Management of immature root with a necrotic pulp and apical periodontitis is a challenging task. The infected root canal space cannot be disinfected with the standard protocol. Obturation of the root canal is difficult because of lack of apical barrier for containing the root filling material. Treatment of choice in such cases is the apexification procedure, i.e., establishing an apical barrier. Apexification can be defined as a method to induce a calcified barrier in a root with an open apex or the continued apical development of teeth with incomplete roots and a necrotic pulp’ Management of immature root with a necrotic pulp and apical periodontitis is a challenging task. The infected root canal space cannot be disinfected with the standard protocol. Obturation of the root canal is difficult because of lack of apical barrier for containing the root filling material. Treatment of choice in such cases is the apexification procedure, i.e., establishing an apical barrier. Calcium hydroxide has been widely used for the induction of hard tissue barrier. However, this material requires 5–20 months to form the hard tissue barrier.^[1] It has also been shown that the use of calcium hydroxide weakens the resistance of the dentin to fracture.^[2] In recent times, mineral trioxide aggregate (MTA) has gained widespread popularity for the apexification procedure. Mineral trioxide aggregate (MTA) was developed by Mahmoud Torabinejad at Loma Linda University in the year 1993 as root end filling material. MTA has the advantage over calcium hydroxide that it can be done in a single visit procedure. It produces apical hard tissue formation with significantly greater consistency than calcium hydroxide.^[3] MTA, a biocompatible material, can be used to create a physical barrier. It also helps in the formation of bone and periodontium around its interface.^[4] A bonded restoration can be placed without any delay, thus reducing the possibility of root fractures. Various authors have reported clinical success using MTA for one-visit apexification. The major disadvantage of MTA is its manipulation due to which its placement in the wide apical area is difficult to achieve. A matrix can be used in apexification procedures against which MTA can be placed and condensed. Use of an apical matrix allows for the predictable placement and judicious use of this expensive material.^[5],^[6],^[7]

CASE REPORT

A 21 yr old patient reported to the Department of Conservative Dentistry and Endodontics, Seema dental college and hospital, Rishikesh with the complaint of an unaesthetic smile. History revealed that the patient had suffered trauma 8 years back. The medical history was not significant. Clinical examination revealed blackish discoloration of tooth 21. The tooth did not demonstrate any abnormal mobility or sensitivity to percussion. Both cold and electric sensibility tests failed to elicit any response. Periapical radiograph showed well-defined periapical radiolucency and wide open apex in relation to tooth 21. The final diagnosis was pulpal necrosis with chronic apical periodontitis in relation to tooth 21. After discussing treatment options, we opted to go for MTA apexification. 21 was accessed and working length was established radiographically. Root canal was chemo-mechanically debrided with circumferential filing using the International Organization for Standardization (ISO) 120 K-file in conjunction with copious amount of Saline. A volume of 3 ml of 17% ethylenediaminetetraacetic acid (EDTA) solution was used for smear layer removal. Radiograph demonstrated the resorption of the apical matrix and periapical lesion. On second visit, an apical barrier of 3-4 mm was established using MTA. A moist cotton pellet was placed over the MTA and access cavity was sealed with IRM. Patient was recalled the next day. On third visit, the setting of MTA was confirmed using finger plugger and the root canal was obturated by sectional obturation technique.

DISCUSSION

Apexification is defined as a method to induce a calcified barrier in a root with an open apex or the continued apical development of an incomplete root in teeth with necrotic pulp. This barrier is mandatory to allow the compaction of the root filling material. Calcium hydroxide has been considered as an efficient material for this purpose.^[8] This chemical has several disadvantages such as difficulty of the patient's recall management and delay in the treatment.^[9] Furthermore, there is a risk of tooth fracture after dressing with calcium hydroxide for extended periods.^[2] The most promising alternative to calcium hydroxide is MTA.^[10] The advantages of this material are (i) reduction in treatment time, (ii) immediate restoration of the tooth, (iii) no adverse effect on the mechanical properties of root dentin. In a prospective study, apexification treatment with MTA showed a high prevalence of healing and apical closure.^[11] The main disadvantage of MTA is its difficult manipulation. Placement of the material in a wide open area is a challenging task and also there is a risk of extruding this expensive material into periapical tissues. Lemon advocated the use of a matrix when the diameter of the perforation is larger than 1 mm to prevent the extrusion of sealing material. Similarly, a matrix can be used for the predictable placement of MTA in apexification procedures. Use of matrix provides a base against which the MTA can be packed.^[12] Various materials have been advocated to be used as a matrix, for example, calcium sulfate, hydroxyapatite, collagen, platelet-rich fibrin. However, the materials mentioned are either not cost-effective or technique sensitive. Calcium sulfate has a very short setting time of 2 min.^[13] Hydroxyapatite is an expensive material. The common limitation shared by these materials is that once placed their position can't be adjusted as required.

CONCLUSION

Managing a tooth with open apex with a biocompatible material MTA has become a single visit procedure. This innovative procedure is predictable and less time-consuming one. Such teeth restored with this technique best serve the needs of the patients.

REFERENCES