The vitality of the dentine-pulp complex is fundamental to the health of the tooth and is a priority for targeting clinical management strategies.1 The overall response of the tooth to injury, such as dental caries, represents the complex interplay between injury, defence and regenerative processes.2 Preservation of vitality of exposed pulp is important in permanent teeth of children to increase the tooth longevity. Pulpal exposures may result from dental caries, iatrogenic mishaps or traumatic injuries.3
Regenerative endodontic procedures involving pulp capping and partial pulpotomy have been in use more than 3o yrs. Regenerative endodontic procedures can be defined as biologically based procedures designed to predictably replace damaged, diseased, or missing structures, including dentin and root structures as well as cells of the pulp dentin complex, with live viable tissues, preferably of the same origin, that restore the normal physiologic functions of the pulp dentin complex. 4-5
Pulpotomy is a vital pulp therapy in which a portion of coronal pulp tissue is removed surgically, and the remaining radicular tissue is covered with a suitable material that protects the pulp from further injury and promotes healing.6-7 In primary teeth, pulpotomy is a preferred procedure as several case studies have suggested pulpotomy as a viable treatment for pulp exposures with pulpitis; the rationale being the healing potential of the remaining radicular tissue and the biocompatibility of pulpotomy agents.8
However, the cells from diseased pulp demonstrate decreased colony formation capacity and slightly decreased cell proliferation rate, but they had similar STRO-1expression and exhibits a similar percentage of positive ex vivo osteogenic induction and dentin sialophosphoprotein expression from STRO-1 enriched pulp cells and makes regenerative procedures possible in irreversible pulpitis.9 Therefore, biocompatible treatments directed at maintaining pulp vitality and increasing tooth longevity would rather be preferred procedure or more suitable for maintaining the vitality of teeth.2
Numerous in vivo and in vitro studies have reported excellent physiochemical and biological properties of MTA, i.e. good sealing ability, hydroxyapatite formation and favourable biocompatibility.10-11 Recent research has shown that MTA, when placed in direct contact with the human dental pulp cells, differentiated them into odontoblast-like cells.12 Therefore, the aim of this study was to evaluate the effectiveness of MTA as pulpotomy agent in permanent teeth with irreversible pulpitis.
MATERIALS AND METHODS
The present study was carried out in the Outpatient Department of Pediatric and Preventive Dentistry, Bhojia Dental College and Hospital, Bhud, Baddi. A total 10 teeth (8 molars, 2 incisors) selected from the patients in the age range of 10-16 years were selected for the study. The study was approved by Institutional Ethical Committee of Bhojia Dental College and Hospital, Bhud, Baddi. The teeth with history of spontaneous nocturnal pain, clinically active caries invading the pulp, incisors with Ellis class III fracture were selected for the study. All the 10 teeth were checked for vitality before inclusion in the study and all responded positive for vitality. The teeth with necrosed pulp or fistula/periapical abscess, internal & external resorption, abnormal mobility periapical radiolucencies were excluded from the study. After doing the standard clinical procedure of MTA Pulpotomy all treated teeth were evaluated for various clinical and radiographical parameters viz pain, swelling, mobility, abscess, sinus tract, discoloration, periapical radiolucency, thickening of lamina dura and tooth discoloration. at 3,6 and 9 and 12 months.
After recording thorough medical and dental history and performing required investigations, informed written consent explaining nature of the study was obtained from the parents of the selected children. All the clinical and radiographic parameters were recorded on a specially designed proforma. The tooth vitality was checked with the electric pulp tester. After administration of local anaesthesia, the tooth was isolated with rubber dam. The crown of tooth and surrounding rubber dam was disinfected by applying hydrogen peroxide (30%) for 30 seconds followed by tincture iodine (5%) for one minute and the disinfectant was inactivated by Sodium thiosulphate solution (5%) for one minute. Access cavity was prepared with a round bur using high speed air rotor handpiece with continuous irrigation using normal saline, and coronal pulp tissue was removed to the level of pulp chamber floor with a sharp spoon excavator. Hemostasis was achieved by irrigating the cavity with sterile saline and use of wet cotton pellets which was placed over exposed pulp stumps for 10-15 minutes. The pulp tissue thus removed was transported in formalin to the Oral Pathology Laboratory for histopathological examination (Figure 1). After achieving haemostasis, the blood clot free pulpal wound was directly covered with approximately 2-mm thick layer of MTA. A sterile cotton pellet moistened with distilled water was placed over MTA and patient was asked to wait for 15- 20 minutes. Then, the final restoration with RMGIC and light cured composite was placed over the MTA. The clinical and radiographical parameters were evaluated for all the teeth at 3,6 and 9 and 12 months. The pain was evaluated by using the visual analog scale (VAS) that is a measurement instrument which tries to measure a characteristic or attitude that is believed to range across a continuum of values and cannot easily be directly measured. Data were complied and Chi- squire test was applied.
Figure 1: Pre-Operative IOPA radiograph
Evaluation of clinical parameters is shown in table 1 and revealed, no pathology on successive follow ups except for discoloration. After 24 hours of evaluation all the patients complained of mild pain and tenderness on percussion, but after 3, 6, 9 and 12 months of follow up, there was complete absence of pain.
Table 1: Evaluation of the parameters at baseline and follow up examination
Radiographic evaluation is shown in table 2, the teeth were assessed for internal and external resorption, periapical radiolucency, and thickening of lamina dura. No abnormal radiographical features were noted after 3, 6, 9 and 12 months (Figure 1-5).
Table 2: Evaluation of the radiographic parameters at baseline and follow up examination
Figure 2: Follow up at 3 months after MTA pulpotomy
Figure 3: Follow up at 6 months after MTA pulpotomy
Figure 4: Follow up at 9 months after MTA pulpotomy
Figure 5: Follow up at 12 months after MTA pulpotomy
The table 3 shows the observations of EPT value that were recorded at baseline and follow up. Histopathological examination of the pulp tissue removed showed chronic inflammatory cells.
Table 3: EPT values at baseline and follow up
Endodontology has shifted towards postponing or avoiding non-biological treatment and descending down the restorative spiral, which would significantly reduce the long-term prognosis for tooth retention and function.13 Recent studies have suggested vital pulp therapy (VPT) as a realistic treatment modality for pulp exposures with supposed irreversible pulpitis.14-16 Vital pulp aims to preserve and maintain pulp tissue that has been compromised but not destroyed by caries, trauma, or restorative procedures in a healthy state. On the other hand VPT for mature permanent teeth with irreversible pulpitis and/or carious pulp exposure remains one of the most challenging/controversial areas in dentistry.17
Various authors used MTA as a pulp dressing for partially pulpotomised permanent molars in a preliminary study and reported a 100% success rate over 12-26 months.18 Like Calcium hydroxide, MTA also has an alkaline pH (12.5) which not only causes denaturation and necrosis of the adjacent pulp but which also confers bactericidal activity. In addition, MTA has been shown to produce less inflammation and higher quality bridge formation and also it possesses osteoinductive property when compared to Calcium hydroxide.19 Clinicians report favourable treatment outcomes and various research reports indicate that this material is biocompatible, encourages pulp, bone and periodontal ligament repair, and it seals well in the presence of fluid.20 White MTA (Angelus) which has less calcium sulphate, was used in the present study because it has very short setting time of 15 min as compared to Proroot MTA which sets about 2.5-4 hours.12
In this study, the age group that was taken was in the range of 10-16 years as there is evidence regarding the effect of the patient’s age and the status of the root apex on the outcome of vital pulp therapy. According to Malekafzali B et al (2011)21 it had been suggested that aged pulp retains the ability to create dentine but at a diminished rate. They also concluded that younger pulps had a better likelihood of potential tissue healing and regeneration. An explanation for this could be provided from a recent review on dental pulp stem cells where it had been demonstrated that ageing was related to reduction of pulpal cell populations leading to compromised pulpal wound healing and regeneration with increasing age.22
The clinical success is measured when there is absence of spontaneous or nocturnal pain, excessive mobility, tenderness on percussion, abscess, swelling or fistula according to previous studies. None of the pulpotomy cases in the present study showed any above mentioned pathological signs and symptoms at follow up examination at 3, 6, 9 and 12 months post operatively. Pain which was present at baseline disappeared at successive follow up visits which might be related to decrease in pulpal inflammation secondary to pulpal regeneration of stem cells present in pulp following pulpotomy procedure. Eghbal et al.23 studied the short term clinical and histological outcomes of MTA pulpotomy of 12 permanent molars with irreversible pulpitis. Clinically, no complaint of discomfort or tenderness on percussion in the next day was reported. Witherspoon et al3 also revealed good clinical and radiographic outcomes of MTA pulpotomy for 19 symptomatic permanent teeth in 14 patients at the follow up of 19.7 months. Dominguez et al24 following histological evaluation of radicular pulp reported that MTA caused minimal pulpal inflammation. Recent reviews and meta-analysis done by various authors also reported high success rates of Pulpotomy in primary teeth with MTA. In contrast Anthonappa et al25 reported no evidence that MTA was better than present materials and techniques as pulpotomy medicament.
In the present study, the EPT values were recorded at baseline for each tooth in which the mean was 10.2± 0.74 before the start of treatment (Table 3). There was no statistically significant difference found between this value and value obtained from control healthy tooth. The pulp responded positively to electric pulp test in all the cases before the treatment and at the follow up examination visits. Results showed no statistically significant difference between the baseline values i.e. preoperatively and the values obtained at follow up visits of 3, 6, 9 and 12 months.
In this study, radiographic parameters i.e. internal and external resorption, periapical radiolucency and thickening of lamina dura that were recorded at 3, 6, 9 and 12 months revealed no abnormal radiographic change.
The present study had few limitations. The clinically significant discoloration was observed in all cases which limit its use in esthetic zone. Histological evaluation was not possible to confirm the hard tissue bridge formation. Larger sample size with longer follow up is required to see the long term success of MTA pulpotomy.
Considering the results obtained in the present study, it can be concluded that the MTA can be used as pulpotomy agents as an alternative to root canal treatment in permanent teeth with irreversible pulpitis. Further clinical trials and research is necessary to compare the effects of MTA alone and in combination with other agents in pulp repair or regeneration of irreversibly damaged radicular pulp on a larger sample size and longer follow up time period. Histological success could not be confirmed which needs extraction of treated tooth, which was not possible in present study.