Author: Dr. Shikha, Dr. Rohit Arora, Dr. Sachin Gupta.
Subharti Dental College, Meerut.

Abstract: Mineral Trioxide Aggregate is a biocompatible material, capable of providing a biological seal in open apices cases. Its use has also been recommended for cases such as pulp capping, regenerative endodontics, perforation repairs etc. Clinical use of MTA in humans has demonstrated their applicability in wet environments, preventing bacterial microleakage and alkalinizing the medium. On account of the predominant presence of calcium oxide in its formula, its biological properties show similarity to those of calcium hydroxide, making it useful for tissue healing. In the present study a modified matrix concept in open apex closure using mineral trioxide aggregate has been potrayed.

INTRODUCTION:

Success of root canal treatment lies in the fact that treated tooth should remain free of any infection and provide a certain amount of strength to the tooth. In teeth with incomplete root development as a consequence of pulp necrosis through trauma or caries, the absence of natural constriction at the end of the canal makes control of filling material difficult. Because of lack of apical constriction an alternative to standard root canal treatment is done, like apexification or root end closure.

Apexification can be defined as a method to induce a calcified barrier in a root with a open apex or continues apical development of teeth with the incomplete root and necrotic pulp (American association of endodontics 2003).

Historically, calcium hydroxide has been the material of choice used to induce the formation of an apical hard tissue barrier before placing a long-term root filling. Granath (1959) was the first to describe the use of calcium hydroxide for apical closure. Before this, nonvital immature teeth were often extracted. Frank ⁶ (1966) popularized the technique in which the canals are debrided and packed with a paste made by mixing calcium hydroxide with carnphorated p-chlorophenol. The Frank technique required the replacement of the calcium hydroxide paste every 3 months until a barrier formed. This could take up to 24 months. Many studies have reported favorable outcomes when calcium hydroxide is used alone or in combination with other materials.

However, despite a long history of use in apical closure procedures, there are several problems relating to the use of calcium hydroxide for apexification. These include the long time required for root apices to close, the number of “dressings necessary to complete closure, the role of infection, and the fracture resistance of teeth after the long-term application of calcium hydroxide. Depending on the study, barrier formation is reported to take anywhere from 3—24 months . The role of infection is also not universally agreed on. Cvek (1992) noted that immature teeth are weakened by filling of the root canals with a calcium hydroxide dressing and a subsequent gutta-percha obturation. Subsequently, the long-term application of intracanal calcium hydroxide has been shown to decrease the fracture resistance of open apex teeth.

Mineral trioxide aggregate (MTA) (ProRoot; Dentsply Maillrfer, Ballaigues, Switzerland) is a material recommended for several dental purposes. The suggested indications for the use o MTA include apical filling of teeth with open apices and apexification therapy (Torabinejad & Chiviari 1999, Shabahang & Torabinejad 2000, Giuliani et al. 2002), root-end lillings (Torabinelad et al. 1993. 1994), pulp capping (Pitt Ford et al. 1996), repair of root perforations (Soluti et al. 1993, Pitt Ford et al. 1995. Holland Pr 5 2001), Similar or even better biocompatibility of MTA when compared with other materials used for these purposes has been reported (Torabinejad et al. 1995a, Mitchell et al. 1999, Keiser et al. 2000). MTA has the ability to induce cementum-like hard tissue when used adjacent to the periradicular tissues and is a promising material as a result of superior sealing properties.

It would appear that MTA has several advantages when compared with the combination of calcium hydroxide—induced apical closure followed by compacted gutta-percha. These are ¹ a reduction in treatment time, thereby facilitating the timely restoration of the tooth; ² the tooth is less likely to fracture and ³ the patient requires fewer visits to the dental office.

The Absorbable Collagen Wound Dressings for Dental Surgery (Collatape, CollaCote, CollaPlug)are soft white, pliable, no friable sponges. Because of the coherent sponge structure, application of the dressings to the wound is easily controlled. The dressings retain their structural integrity even when wet. This also serves as a barrier in the apical canal against which MTA can be compressed.

This report demonstrates the use of MTA as apical plug in immature open apex where apial matrix was inadventally created by CollaCote membrane.

CASE REPORT:

A 20 year old male patient, reported to the Department of Conservative Dentistry and Endodontics. Patient had discoloration and swelling with respect to upper left central incisor. Patient gave history of fall from roof 9 years back.

Radiographic evaluation revealed an open apex with a very wide canal and marked radiolucency periapically [Figure 1].

Figure 1. Pre Operative Radiograph	Figure 2. Working length	Figure 3. Collacote ® Absorbable Synthetic Collagen was used to Create a Barrier at the Apex

Figure 4 Mineral Trioxide Aggregate (M.T.A.) After Mixing The Powder With Saline.	Figure 5. MTA Plug	Figure 6. Obturated Canal with Warm Gutta Percha Technique (Obtura)

Access cavity preparation was done with the help of endo access bur, working length was determined with 80 no. ISO K file, as this was the file which binded the canal [Figure 2]. Canal dedridement was done; cleaning was performed using ISO K file upto no. 120 file and copious irrigation with 5.25 % sodium hypochlorite and saline water. Canal was dried using sterile paper points, then insertion of CollaCote membrane was done with the help of pluggers into the periapical tissue [Figure 3].

Then white MTA (Pro-Root Mta Dentsply Mailefer Ballaigus, Switzerland) mixed to a paste like consistency with sterile water and delivered to the canal using MTA gun (MAP system) and condensation was followed using series of endodontic plugger [Figure 4]. A radiograph was done to check the thickness of the plug [Figure 5]. Patient was made to sit for 3-4 hours until setting of MTA.

After that rest of the canal was dried and filled with warm gutta percha technique (Obtura) [Figure 6]. Coronal seal was maintained using light cure Glass isomer cement. A final radiograph was taken and patient was called after one week for follow up.

DISCUSSION:

Apexification with use of calcium hydroxide has shown a great success. The mean time for the formation of apical barrier being 12- 19 months (Dominguez rayes et al 2005). In such a treatment, the formation of apical barriers necessary to allow the filling of root canal system without risk of overfilling.

Failure of this technique may be because of several factors

1. Repeated overfilling with the material with high ph (12.5) can induce a necrotic zone in a periapical bone
2. The lack of coronoradicular restoration and thus of an appropriate coronal seal whist the canal system is not filled.
3. A prolonged contact with calcium hydroxide induces a significant decrease in intrinsic properties of exposed dentine.

The last two factors are directly responsible for root fracture occurring before the end of the treatment.

To avoid this risk of fracture, apexification in one visit, by placing an apical plug of MTA in 4 mm of the canal. Obturation of root canal system and coronal restoration in the tooth immediately are thus possible and are regarded as key elements for long term conservation of treated tooth.

CONCLUSION:

The use of MTA in combination with CollaCote membrane as matrix showed a positive intial outcome for the immature tooth. In such cases long term follow up are necessary to ensure success.

REFRENCES:

1. Economides N, Pantelidou O, Kokkas A, Tziafas D. Short-term periradicular tissue response to mineral trioxide aggregate (MTA) as root-end filling material. Int Endod J. 2003;36:44–8.
2. De Deus G, Ximenes R, Gurgel-Filho ED, Plotkowski MC, Coutinho-Filho T. Cytotoxicity of MTA and Portland cement on human ECV 304 endothelial cells. Int Endod J. 2005;38:604–9.
3. Felippe WT, Felippe MC, Rocha MJ. The effect of mineral trioxide aggregate on the apexification and periapical healing of teeth with incomplete root formation. Int Endod J. 2006;39:2–9.
4. Ribeiro DA, Matsumoto MA, Duarte MA, Marques ME, Salvadori DM. Ex vivo biocompatibility tests of regular and white forms of mineral trioxide aggregate. Int Endod J. 2006;39:26–30.
5. Takita T, Hayashi M, Takeichi O, Ogiso B, Suzuki N, Otsuka K, et al. Effect of mineral trioxide aggregate on proliferation of cultured human dental pulp cells. Int Endod J. 2006;39:415–22.
6. Torabinejad M, Watson TF, Pitt Ford TR. Sealing ability of a mineral trioxide aggregate when used as a root end filling material. J Endod. 1993;19:591–5.
7. Torabinejad M, Chivian N. Clinical applications of mineral trioxide aggregate. J Endod.1999;25:197–205.
8. Pradhan DP, Chawla, Gauba K, Goyal A. Comparative evaluation of endodontic management of teeth with unformed apices with mineral trioxide aggregate and calcium hydroxide. J Dent Child.2006;73(2):79–85.
9. Lemon RR. Nonsurgical repair of furcal perforations with defects. Dent Clin North Am.1992;36:349–457.
10. Rafter M, Baker M, Alves M, Daniel J, Remeikis N. Evaluation of healing with use of an internal matrix to repair furcation perforations. Int Endod J. 2002;35:775–83.
11. Al-Daafas A, Al-Nazhan S. Histological evaluation of contaminated furcal perforation in dogs teeth repaired by MTA with or without internal matrix. Oral Surg Oral Med Oral Pathol Oral Radiol Endod.2007;103:92–9.
12. Jantarat J, Dashper SG, Messer HH. Effect of matrix placement on furcation perforation repair. J Endod. 1999;25:192–6.
13. Bargholz C. Perforation repair with mineral trioxide aggregate: A modified matrix concept. Int Endod J. 2005;38:59–69.
14. Mesimeris V, Sade E, Baer PN. Calcium sulfate as a biodegradable barrier membrane: A preliminary report on the “Surgiplast” technique. Periodontal Clin Invest. 1995;17:13–6.
15. Alhadainy HA, Himel VT, Lee WB, El Baghdady YM. Use of a hydroxylapatite-based material and calcium sulfate as artificial floor to repair furcal perforations. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1998;86:723–9.
16. Zou L, Liu J, Yin SH, Tan J, Wang FM, Li W, et al. Effect of placement of calcium sulphate when used for repair of furcation perforation on seal produced by a resin-based material. Int Endod J.2007;40:100–5.
17. Holden DT, Schwartz SA, Kirkpatrick TC, Schindler WG. Clinical outcomes of artificial root-end barriers with mineral trioxide aggregate in teeth with immature apices. J Endod. 2008;34(7):812–7.
18. Broon NJ, Bramante CM, Assis GF, Bortoluzzi EA, Bernardineli N, Moraes IG, et al. Healing of root perforations treated with mineral trioxide aggregate (MTA) and Portland cement. J Appl Oral Sci.2006;14:305–11.
19. Holland R, Mazuqueli L, Souza V, Murata SS, Dezan E., Jr Influence of the type of vehicle and limit of obturation on apical and periapical tissue response in dogs teeth after root canal filling with mineral trioxide aggregate. J Endod. 2007;33:693–7.
20. Sottosanti J. Calcium sulfate: A biodegradable and biocompatible barrier for guided tissue regeneration. Compend Contin Educ Dent. 1992;13:226–34.