Comparison of Mineral Trioxide Aggregate and Calcium Hydroxide as pulpotomy agents in Primary Molars

Assistant Professor, Department of Conservative Dentistry & Endodontics, Pioneer Dental College & Hospital, Dhaka, Bangladesh. Professor, Dean, Faculty of Dentistry, Chairman, Department of Conservative Dentistry, BSM Medical University, Dhaka, Bangladesh. Professor, Department of Conservative Dentistry & Endodontics, BSM Medical University, Dhaka, Bangladesh. Associate Professor, Department of Conservative Dentistry & Endodontics, BSM Medical University, Dhaka, Bangladesh. Lecturer, Department of Conservative Dentistry & Endodontics, Dental Unit, Rajshahi Medical College & Hospital, Rajshahi, Bangladesh.

Preservation of primary teeth before the eruption of permanent teeth is desirable since they help to determine the shape of dental arches, maintain the space between teeth, prevent detrimental tongue and speech habits, preserve aesthetics, and maintain chewing function.Hence, teeth with caries should ideally be restored rather than be extracted. 1In primary teeth, especially, there is a high chance of pulp exposure because the thickness of dentine is thin in these teeth in comparison to permanent teeth.Calcium hydroxide has been a popular pulpotomy agent for vital pulp therapy and is widely used clinically.It was introduced by Herman as a biologic dressing. 5Despite its apparent success in vital pulp therapy, considerable confusion and condemnation of this material have long persisted because Ca(OH) 2 -in its pure state and in the original formulations-actually kills a certain amount of tissue when placed in direct contact with the pulp rather than merely functioning as a biologic dressing.Because of its alkalinity (pH of 12), it is so caustic that when placed in contact with vital pulp tissue, the reaction produces a superficial necrosis of the pulp. 7Studies have also shown that Ca(OH) 2 is extremely toxic to cells in tissue culture, also it has some tissue altering and dissolving effects. 7,8 neral Trioxide Aggregate (MTA) was developed and introduced in 1993 at the Loma Linda university, California, USA, as a root-end filling material and was approved by The US Food and Drug Administration for human teeth treatment in 1998. 9, 10The principal components of the grey-coloured formula are Tricalcium oxide, Tricalcium aluminate, Tricalcium silicate, Tetracalcium aluminoferrite and Calcium sulfate dehydrate.The more aesthetic white-coloured preparation lacks the tetracalcium aluminoferrite.Lately,MTA has been used as a pulpotomy material in primary molars and it was found to be a successful material. 9, 11A was developed with the purpose of serving as an apical root end filling material, but it has also proven to be successful in vital pulp therapy procedures both in animals 12, 13 and humans. 4Many clinical studies have recommended that, MTA is a biocompatible material and its sealing ability is better than that of amalgam or zinc oxide eugenol. 4, 15Furthermore, its ability to stimulate cytokine release from bone cells has been demonstrated which means that it can actively promotes hard tissues formation. 4Although the use of MTA has been extended to pulp capping and pulpotomy of primary teeth but, there are only few studies have been published regarding its clinical success.Therefore, in the present study, the clinical outcome of MTA in pulpotomy of primary teeth was compared with that of Calcium hydroxide at 3, 6, and 12 months follow-up periods.

MATERIALS AND METHODS
Patients with 40 deep carious primary molar teeth were selected requiring pulpotomy treatment in the department of Conservative Dentistry and Endodontics, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, along with a preoperative intra oral periapical radiograph.The procedure and its possible discomfort, or risks, and benefits were explained fully to the parents of the children involved, and their informed consent, as approved by the institutional review board of human subjects experiments, were obtained prior to the investigation.Sample size was selected into two test groups (n=40 with cotton roll and with the used of saliva ejector.After caries removal and pulp chamber exposure, the coronal pulp was amputated with a round bur & a spoon excavator.Haemorrhage was controlled by placing sterile, saline-wetted cotton pellets on the radicular pulp stumps under slight pressure. Patients in Experimental Group 1 -Pro-Root MTA (Dentsply, Maillefer, USA) was mixed according to the manufacture's recommendations using plastic spatula, in ratio 3: 1.Then, smooth mix of MTA was obtained and then applied over the pulp and into the base of the cavity.Then, by using a sterile cotton pellet moistened with distilled water MTA was condensed properly over the chamber.After the setting of MTA, the rest of the cavity was filled with Fuji-IX Glassionomer cement.Bite was checked for any high spots and 2 coats of Varnish were applied over the Glassionomer Filling.Patients in Control Group 2 -Ca(OH) 2 (DEEPLL DENTAL PRODUCTS OF INDIA)powder was mixed with saline to a thick consistency.The paste was carefully placed on the pulp stump surface 1 to 2 mm thick.The orifices and the rest of the pulp chamber were filled respectively with a reinforced 2-mm thick layer of zinc oxide-eugenol paste and Glassionomer (Fuji-IX) Cement and a coat of Varnish was applied over the Glassionomer Filling.
After initial Clinical and Radiographic examinations teeth were evaluated after 3, 6, and 12 months forclinical signs or radiographical signs of failure.If calcific metamorphosis occurred, it was noted but not regarded as a treatment failure.The treatment was judged as successful if the teeth met with the following criteria:

Results:
The study involve patients with 40 deep carious primary Molar teeth were selected requiring pulpotomy treatment.All cases treated with MTA and Ca (OH) 2 as pulpotomy agents.The follow-up period was 12 months.The results are showed in the following Table .I -V.At 3-months following treatment all, MTA pulpotomy and Ca(OH) 2 pulpotomy showed 100% success rate both in clinical and radiographic assessments.Pain, postoperative swelling, tenderness or mobility has not detected in any cases.In radiographic examinations, there was also no sign of radiolucent area.At 6-months interval, however one patient in Ca (OH) 2 pulpotomy group reported pain in molar tooth and 1 patient in MTA pulpotomy and 3 patients in Ca (OH) 2 pulpotomy group reported pain during 12 th months follow-up.The overall assessment of MTA pulpotomy and Ca (OH) 2 pulpotomy treatments were successful; there was only postoperative swelling 15.0% in Ca (OH) 2 pulpotomy group, there was no mobility or sinus formation in both groups and tenderness on percussion 5.0% and 15.0% in MTA pulpotomy and Ca (OH) 2 pulpotomy group respectively.Radiographic examination also showed Periapical/inter-radicular radiolucency 5.0% and 15.0% in MTA pulpotomy and Ca (OH) 2 pulpotomy group respectively.Table V shows the radiographic assessment of the groups at evaluation period.Periapical/interradicular radiolucency was observed only during 12 months follow up which was 1(5.0%) in group I and 3(15.0%) in group II.No statistical significant (p>0.05)difference was found between two group during 12 months follow-up.

Discussion:
Pulpotomy is effective for the treatment of carious or mechanical pulp exposure in primary teeth. 2, 15Due to its high success rate, it is an acceptable clinical technique for treating inflammation of coronal pulp.Treatment usually consists of removal of coronal pulp followed by application of medicament such as MTA, Formocersol, Calcium hydroxide, Ferric sulphate, Gultaraldehyde, and then final restoration. 15n the present study, 40 primary teeth were treated either by MTA or Ca(OH) 2 and the clinical outcomes at 3, 6, and 12-months intervals were examined.The assessment was performed according to clinical and radiographical evaluations.In clinical evaluation, pain, swelling, tenderness, mobility, sinus was examined.On the other hand, radiographic examination was performed according to presence or absence of radiolucent area.
The result of the present study showed that regarding pulpotomy with MTA, all cases showed successful at 3, 6, and 12-months following treatment but one patient reported spontaneous pain at 12-months.However, in Ca(OH) 2 group, three patients reported spontaneous pain at 12-months.In these cases treatment was done by pulpectomy.The exact reason of pain is not clearly understood.However, It is possible that the pulp of these teeth were inflamed prior to treatment but without clinical signs of such inflammation.The subsidence of symptoms may be partly due to the effect of the medication but it may also be a result of the pulps undergoing necrosis at which stage the symptoms generally disappear until further apical periodontitis develops later.This study examined the clinical and radiographic success rates of primary molar tooth pulpotomies with MTA, a material with evidence-based success in many endodontic procedures.Several in vitro and in vivo studies have shown that MTA prevents microleakage, is biocompatible and nonresorbable, has low solubility and high comprehensive strength, and promotes tissue regeneration when it is placed in contact with dental pulp or periradicular tissues. 15,17,18,19,20 Ca H) 2 was selected as the control pulpotomy agent because it is currently considered the standard therapeutic agent for pulpotomy procedures in primary molar teeth.Ca(OH) 2 has a long and proven record as an effective pulp therapy agent, including pulpotomies, and it is not expensive.On the other hand, Ca(OH) 2 has high solubility and low strength.Ca(OH) 2 has been reported to produce more inflammation and lower quality bridge formation when compared with MTA in monkeys and dogs. 12, 19Similar results were found when human third molars were used to compare the effect of pulp capping with MTA and Ca(OH) 2.

21
The Ca(OH) 2 group in this study showed 3 teeth with pathologic signs and symptoms and they were regarded as failures at the 12-month evaluation.Walton and Torabinejad believe that failure usually results from bacterial contamination through microleakage around the restoration and through the porous bridge at the pulpotomy site. 22Ca(OH) 2 offers no protection against microleakage while MTA remains stable and resists microleakage after it sets. 17MTA has been shown to prevent bacterial penetration and to be biocompatible when used for direct pulp capping and pulpotomy in mechanically exposed pulps. 15Such characteristics were also evident in this study of both mechanically and cariously exposed pulps.Periapical/inter-radicular radiolucency occurred in the four teeth with clinical symptoms -one of these (MTA pulpotomy case) had a periapical radiolucency and the other three (Ca(OH) 2 pulpotomy cases) had periapical & inter-radicular radiolucencies.The presence of these findings is consistent with the clinical findings (pain, tenderness to percussion, presence of gingival swelling).It is to be expected that necrosis and infection of the remaining pulp would manifest radiographically in this manner and therefore the results of this study are consistent with contemporary dental treatment.In the cases of Ca(OH) 2 pulpotomy, inter-radicular /furcation radiolucency is unlikely since the pulp chamber will be filled with the pulpotomy and restorative materials and hence, this part of the tooth is unlikely to be infected.However, if the radicular pulp becomes necrotic and infected then periapical radiolucency will develop because of the release of bacteria and their toxins via the apical foramina.Regarding discolourations of treated teeth in MTA pulpotomy it was found that there was brown to black color which was more prominent on the clinical crown of first primary molars than on the second primary molars.It may be due to thickness of enamel and dentine of first primary molar is less than the second primary molars.Therefore, Mortazavi M. et al (2009) suggested that the use of more recent product of white MTA could solve this problem.Based on the present study together with the previous studies, it can be said that, MTA has better biocompatibility and high success rate and the problem of these discolorations are not the major issue.Calcific metamorphosis was the most common noteworthy radiographic finding in both groups in this study, although it is not considered as a criterion for success or failure in the treated teeth.It results from vigorous odontoblastic activity and indicates pulpal vitality.Calcific metamorphosis is a common radiographic finding in pulpotomized teeth and in the present study, it was observed in 2 teeth treated with Ca(OH) 2 and in 4 teeth treated with MTA.

Conclusion:
MTA is a recently developed biocompatible material advances to propose of potential pulpotomy material for various pulpal procedures.Based on this Clinical and radiographic evaluation study of 3, 6, and 12months follow-up, MTA pulpotomy have high success rate than Ca(OH) 2 Pulpotomy.So, MTA could be used as a safe material for pulpotomy in cariously or mechanically exposed primary teeth and could be a substitute for Ca(OH) 2 .

( 1 )
Clinical assessment: (a) the teeth showed no symptoms of pain, (b) No pain on palpation or percussion, (c) No evidence of swelling or sinus tract& (d) No pathological mobility, and (2) Radiographic assessment: (a) the teeth showed no periapical or interradicular radiolucency, (b) no widening of periodontal ligament or no internal or external root resorption.

Fig 1 :
Fig 1: Bar diagram showing the sex distribution of the study patients.

Fig 2 :
Fig 2: Bar diagram showing the pain status of the study teeth during 12 months follow up.

Table II : Sex distribution of the study patients (n=40)
This study was conducted among 40 patients and they were divided into Male and female.Female was predominant in both groups which was 12(60.0%) in group I and 14(70.0%) in group II.Male female ratio was 1:1.9 in the whole study.No significant (p>0.05)difference was observed in Chi square test regarding sex of the study patients.

Table
III shows the pain status of the study teeth during 12 months follow up and observed that, pain was not found in both group at baseline and 3 rd months follow-up.After 6 months follow up one patient in group II had pain, which was moderate.After 12 months follow up 1(5.0%) of the study patients had Spontaneous pain in group I.In group II, 3(15.0%) had pain among them 2(10.0%)had Sharp/Spontaneous pain and 1(5.0%) moderate pain.No significant (p>0.05)difference was observed in Chi square test.Other results are depicted in the above table.