Vital Pulp Therapy Using MTA: A Case Series

by Anu Bhalla, DMD, FRCD(c); Yosef Nahmias, DDS, MSc

One of the primary purposes of the human dental pulp is dentin formation. If the pulp undergoes pathological changes such as inflammation due to carious exposure, normal dentin and root growth can be disrupted. Traditional treatment for carious exposed pulps has been root canal treatment because direct pulp capping, partial or full pulpotomy in such cases has been considered unpredictable and therefore contraindicated. Historically, materials such as calcium hydroxide, hydrophilic resins and resin-modified glass ionomer cements have been used. Success rates in such cases have been reported between 30 to 85 percent in retrospective studies.1 Although calcium hydroxide apexification2 has shown high success rate, the time required for treatment completion can be up to 15-month rendering this option time consuming and undesirable. Furthermore, studies have also shown risk of root fracture with long-term use of calcium hydroxide.3 In the past decade, a new material called mineral trioxide aggregate (MTA) was developed at Loma Linda University. Numerous studies have yielded promising results using MTA for root end filling, perforation repair, vital pulp therapy (direct pulp capping, partial or full pulpotomy) and apical barrier formation.4 MTA is currently recommended as the material of choice for the treatment of teeth with immature apices.

MTA is a bioactive silicate cement consisting of tricalcium silicate, tetracalcium aluminate, tricalium oxide and silicate oxide.5 MTA has been reported to induce pulpal cell proliferation and hard tissue formation such as osteogenesis and dentinogenesis. It can stimulate immune cells to release lymphokines and stimulate bone coupling factors necessary for biomineralization and healing of osseous periapical defects, inducing the regeneration of cementum and PDL.6 Furthermore, in most studies there was decreased inflammation associated with MTA when compared to other materials used for the same purpose.5 This material is successful due to its biocompatibility, good sealing ability, high compressive strength, alkaline pH and slow release of calcium ions. It sets in the presence of moisture with an approximate initial setting time of up to four to six hours, depending on particle size, powder to water ratio, temperature, presence of water, entrapped air5 and particular brand used. This paper intends to report two cases that used full pulpotomy and direct pulp capping as an alternative to root canal treatment in permanent teeth with carious pulp exposures.

CASE 1:
A 21-year-old female presented to our office for evaluation of tooth #46 with a chief complaint that “the tooth my dentist refilled is hurting”. The patient presented with a non-contributory medical history. She reported the restoration on #46 was replaced about one month prior and has been experiencing chewing and cold pain since then. Radiograph examination revealed resin restoration on occlusal of #46 with no evidence of periapical pathology (Fig. 1). Clinical testing revealed pain upon percussion, pain to biting when tested with the tooth slooth and a lingering response to cold. Considering the clinical and radiographic findings, treatment options including root canal treatment, extraction and pulpotomy were presented to the patient. She opted for the MTA pulpotomy for tooth #46.

FIGURE 1.

Under local anesthesia and rubber dam isolation, the existing resin restoration was removed. Extensive hemorrhage was encountered upon access into the pulp chamber. The coronal pulp was removed using slow speed round bur and hemorrhage was still noted from all the canals (Fig. 2). A cotton pellet wet with six percent sodium hypochlorite (NaOCl) was placed in the pulp chamber for five minutes (Fig. 3). Upon removal of the cotton pellet, no hemorrhage was noted (Fig. 4). ProRoot MTA (Dentsply, York, PA) was then incrementally placed over the orifices and in the pulp chamber until an adequate thickness of about 1.5-2mm was established (Fig. 5). Geristore (DenMat, Lompoc, CA) was used as base followed by a bonded composite restoration to provide an adequate seal (Fig. 6). Bite and occlusion were reduced accordingly. The patient was then followed up for the next year during which she remained asymptomatic. Clinical testing at her 12-month recall revealed percussion, apical palpation, bite testing with tooth slooth and cold testing were all within normal limits (Fig. 7).

FIGURE 2. Hemorrhage encountered from all canals after coronal pulp excavation.

FIGURE 3. Cotton pellet wet with 6% NaOCl placed in pulp chamber for 5 minutes.

FIGURE 4. Complete hemostasis from all canals after removal of NaOCl soaked cotton pellet.

FIGURE 5. ProRoot MTA placement over pulp orifices and pulp chamber.

FIGURE 6. Postoperative radiograph of tooth #46 showing ProRoot MTA at level of the orifices with permanent resin restoration.

FIGURE 7. Radiograph of tooth #46 at 12-month recall showing normal periodontal ligament and anatomical structure.

CASE 2:
An eight-year-old male presented for evaluation of the mandibular left first molar with the chief complaint from dad “our dentist said my son needs a root canal”. Patient had a non-contributory medical history. Patient reported a dental history of mild cold pain from tooth that started a month ago. Radiographic examination revealed distal decay extending to the distal pulp horn on #36 as well as open apices of mesial and distal roots (Fig. 8). Clinical testing showed percussion, apical palpation and periodontal probi
ng were all within normal limits. Tooth #36 was cold positive but this remitted once the stimulus was removed, indicating reversible pulpitis. Considering the clinical and radiographic findings, different treatment options including root canal treatment, full and partial pulpotomy using MTA or calcium hydroxide were presented and MTA vital pulp therapy was performed on tooth #36.

FIGURE 8. Preoperative radiograph of tooth #36 with deep distal decay and immature root apices.

A similar protocol as case 1 was followed to complete direct pulp capping of tooth #36 (Fig. 9). Caries indicator dye was utilized to ensure all decay removed prior to MTA placement. Following treatment completion, the patient was followed up for the next two year. During this time, the patient remained asymptomatic. Clinical tests of #36 at the 12-month and 24-month recall appointment revealed normal response to cold testing with no spontaneous pain or discomfort to percussion. Dentinal bridging, increase in root thickness as well as evidence of continued apical root development of the mesial and distal roots was observed radiographically at the 12-month and 24-month recall (Fig. 10 and Fig.11, respectively). A greying discoloration of the tooth was noted at 24-month recall.

FIGURE 9. Postoperative radiograph with ProRoot MTA pulp cap and permanent resin restoration.

FIGURE 10. Radiograph of tooth #36 at 12-month recall showing continued developing root apices and dentin bridge formation under MTA.

FIGURE 11. Radiograph of tooth #36 at 24-month recall showing evidence of almost complete apical closure and lateral root development.

Traditionally, pulpotomies are considered an emergency procedure for permanent mature teeth until root canal treatment can be accomplished.7 Several studies have assessed the outcome of MTA pulpotomy in symptomatic mature permanent teeth and their results have been promising. These studies have revealed good clinical and radiographic outcomes8, histological dentinal bridge formation9, healthy periapical status and positive electric pulp testing of permanent mature teeth with irreversible pulpitis treated with MTA pulpotomy at 24 and 42-month recalls.7 Another study showed 82 percent survival rate without any complimentary treatment required at 24 months.10

The key for success for vital pulp therapy is case selection. One of the main issues in vital pulp therapy is the status of the pulp tissue. It has been suggested that the degree of pulpal bleeding may be a better indicator of pulpal inflammatory status than clinical or sensibility testing alone.11 For example, increased bleeding upon pulpal exposure that does not stop after one to ten minutes of NaOCl soaked pellet with direct pressure suggests the inflammatory response may extend deeper into the pulp indicating a modification in treatment such as root canal treatment.1 Other factors besides control of bleeding that can influence the success rate include the use of appropriate aseptic procedures such as rubber dam islolation, pre-operative presence of a healthy periodontium and appropriate coronal seal following vital pulp therapy completion.11 Furthermore, regular follow-ups are also essential. These are to ensure maintained periapical and pulpal health. If signs of canal calcification are noted accompanied with symptoms, definitive root canal treatment may be indicated.

MTA is an effective pulp-capping material because it is able to stimulate a hard tissue bridge and continued root formation as seen in Case 2. Shabahang3 states that for irreversible pulpitis cases, vital pulp therapy is still available as long as partial or full pulpotomy will remove all of the irreversibly inflamed tissue, as shown in case 1. Bogen et al in 2008 noted four important controlled variables for vital pulp therapy cases: complete caries control, visible hemostasis, verified MTA setting and placement of bonded composite. According to Krakow,12 the criteria for success in exposed incompletely formed teeth with vital pulp include continued root formation, completion of root apex, and maintenance of pulp vitality and stimulation of a new layer of dentin at the orifice of the canal. All of these criteria were evident in both the cases presented in this case report.

This article reported alternative treatment options to traditional root canal therapy. Ultimately, the treating clinician must make an informed treatment decision utilizing the clinical and radiographic findings along with available research. In conclusion, MTA vital pulp capping and pulpotomies are predictable, reproducible and reliable procedures provided that appropriate clinical guidelines and aseptic measures are utilized. OH


Dr. Yosef Nahmias was born and raised in Mexico City. After he had graduated from the Universidad Tecnologica de Mexico, School of Dentistry, in 1980. He earned his Master’s of Science degree in Endodontics in 1983 from Marquette University in Milwaukee, Wisconsin. Dr. Nahmias has authored and published many articles. He continues to lecture in Canada, Mexico and across South America. The University of Toronto, Faculty of Dentistry has involved Dr. Nahmias in teaching their postgraduate level students in endodontics. Dr. Nahmias resides in Toronto and has maintained a private practice specializing in endodontics in the town of Oakville, Ontario since 1983.

Dr. Anu Bhalla was born in India and immigrated to London, Ontario. She graduated from the Ivy League institute, University of Pennsylvania, School of Dental Medicine in 2011. Dr. Bhalla then moved to Los Angeles for her specialty training in Endodontics at the University of California, Los Angeles. Dr. Bhalla is a fellow of the Royal College of Dentists of Canada and is on track to becoming a Diplomat of the American Board of Endodontics. She currently resides in Toronto, Ontario and maintains a practice limited to Endodontics in Oakville, Ontario.

Oral Health welcomes this original article.

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