Journal of Pharmacy And Bioallied Sciences

: 2021  |  Volume : 13  |  Issue : 5  |  Page : 608--611

Antimicrobial efficacy of different pulp-capping materials against Enterococcus faecalis: An In vitro study

Jenny Atom1, Ningthoukhongjam Rati Devi2, Ronel Lairenlakpam2, Mohammed Hussain Dafer Al Wadei3, Abdulrahim R Hakami4, Abdulkarim S BinShaya5,  
1 Department of Conservative Dentistry and Endodontics, Dental College, RIMS, Imphal East, Manipur, India
2 Department of Conservative Dentistry and Endodontics, Dental College, JNIMS, Imphal East, Manipur, India
3 Department Restorative Dental Science, College of Dentistry, King Khalid University, Abha, 61481, Saudi Arabia
4 Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, Abha, 61481, Saudi Arabia
5 Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia

Correspondence Address:
Jenny Atom
Department of Conservative Dentistry and Endodontics, Dental College, RIMS, Lamphelpat, Imphal West, Manipur


Aim: The present study aims to assess the antimicrobial action of three different pulp-capping agents against Enterococcus faecalis. Materials and Methods: Three pulp-capping agents were chosen for this study: Calcicur, mineral trioxide aggregate (MTA)-Angelus, and Dycal. The zone of inhibition produced by these three pulp-capping agents was measured at 24 h and 72 h to assess their antimicrobial efficacy against E. faecalis. The agar diffusion method was used to examine the antimicrobial effect of pulp-capping agents. Mueller-Hinton agar plates were used to inoculate the microorganisms. Analysis of variance (ANOVA) and Tukey's post hoc tests were done to compare the different groups. P < 0.05 was considered as statistically significant. Results: At 24 h, the highest zone of inhibition was found in MTA-Angelus (3.32 ± 0.11 mm), followed by Dycal (2.02 ± 0.46 mm) and Calcicur (1.84 ± 0.92 mm). After 72 h, MTA-Angelus demonstrated a zone of inhibition of 4.60 ± 0.22 mm, followed by Dycal (3.48 ± 0.74 mm) and Calcicur (2.90 ± 0.18 mm). ANOVA test showed a highly statistical significance. A statistically significant difference (P < 0.001) was shown between MTA-Angelus and Dycal. Calcicur did not show any significant difference. Conclusion: This trial found that the freshly mixed MTA-Angelus has a significantly superior antimicrobial effect against E. faecalis than Dycal and Calcicur.

How to cite this article:
Atom J, Devi NR, Lairenlakpam R, Dafer Al Wadei MH, Hakami AR, BinShaya AS. Antimicrobial efficacy of different pulp-capping materials against Enterococcus faecalis: An In vitro study.J Pharm Bioall Sci 2021;13:608-611

How to cite this URL:
Atom J, Devi NR, Lairenlakpam R, Dafer Al Wadei MH, Hakami AR, BinShaya AS. Antimicrobial efficacy of different pulp-capping materials against Enterococcus faecalis: An In vitro study. J Pharm Bioall Sci [serial online] 2021 [cited 2022 Jul 1 ];13:608-611
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Pulpal damage may ensue from remnant dentinal microorganisms postcavity preparation. The use of an antimicrobial pulp-capping agent under permanent restoration has become an essential step to avoid any pulpal damage. Nevertheless, the long-term success of this treatment may be uncertain due to the survival and replication of some of the microorganisms within dentin, pulp, and/or periapical tissues.[1]

In the year 1756, Phillip Pfaff performed the first pulp-capping procedure by covering the area of exposed vital pulp with a tiny piece of gold to help healing. Since then, the epoch of vital pulp treatment has been significantly improved with the introduction of numerous pulp-capping agents. A well-functioning vital pulp can initiate several defense mechanisms against the invading microorganisms and thus protect the body. Thus, it is always important to restore the vitality of an exposed pulp instead of substituting it with a biocompatible material after pulpal exposure. There has been a demonstrable high success rate with direct pulp capping of carious pulpal exposure in young teeth.[2],[3]

Mineral trioxide aggregate (MTA) has exceptional biocompatible properties and stimulates hard tissue formation, which performs as a barrier and conserves the vitality of the damaged pulp, thus eliminating the necessity of a root canal treatment. MTA is composed of bismuth oxide, CaSiO4, calcium sulfate, calcium carbonate, and calcium aluminate.[4] Dycal is a radiopaque, self-setting (2.5–3.5 min) calcium hydroxide-based material active in indirect and direct pulp-capping procedures. The alkalinity of Dycal stimulates secondary dentin formation when it comes in direct contact with the pulp.[5]

Among various inherent properties of pulp-capping agents, the antibacterial property influences the success of the treatment. In addition to antibacterial activity, the optimum flow property also helps eliminate remnant microorganisms present within and around the exposed pulp without damaging pulp tissue. Therefore, the present study was performed to assess the antimicrobial efficacy of different pulp-capping agents against Enterococcus faecalis.

 Materials and Methods

Three pulp-capping materials were selected for this study as follows.

Calcicur: A water-based calcium dihydroxide paste with pH of around 12.5Mineral trioxide aggregate-Angelus®: Powder containing type Portland cement, tricalcium silicate, bismuth oxide, tricalcium aluminate, dicalcium silicate, and tetra-calcium aluminoferriteDycal: Two-paste system made of a catalyst paste (calcium hydroxide, N-ethyl-o/p-toluene sulfonamide, titanium oxide, zinc stearate, zinc oxide, and iron oxide pigments) and a base paste (1,3-butylene glycol disalicylate, zinc oxide, calcium tungstate, calcium phosphate, and iron oxide pigments).

Preparation of the medium for Enterococcus faecalis

Sterilized pipettes of 20 mL were used to pour the prepared Muller-Hinton Agar medium into sterile Petri dishes up to a depth of 4 mm (20 mL) which are placed on a flat horizontal surface. The Petri dishes were stored below 4°C in a refrigerator and used within 1 week after preparation.

A sterile wire loop was used to pick the E. faecalis colonies which had comparable morphology. The microorganisms were transferred into a sterile test tube containing 1.5 mL of sterile brain–heart infusion broth. The test tube was incubated for 24 h at 37°C to cultivate a temperately turbid bacterial suspension. The density of bacterial suspension is standardized and was compared with 0.5 McFarland units of the barium sulfate standard. The standard corresponds to 108 colony-forming units per milliliter.

Agar diffusion method for assessment of antimicrobial activity

The agar diffusion method was used to examine the antimicrobial activity of pulp-capping materials. The E. faecalis bacterial stock culture was grown over the complete night in brain–heart infusion broth and inoculated in plates containing Mueller-Hinton agar. Sterile cotton swabs were used to inoculate the media. A copper puncher was used to prepare wells of 4 mm diameter and 4 mm depth on plates aseptically. The plates were immediately filled with freshly prepared test materials. Soon after that, all the agar plates were incubated at 37°C and assessed after 24 h and after 72 h. The diameter of zone of inhibition was measured in millimeters after incubation.

Statistical analysis

The data were analyzed using SPSS 20.0 (SPSS, Inc., Chicago, IL, USA) version software. Tukey's post hoc tests and one-way analysis of variance (ANOVA) were used to compare the intergroup data and within the groups. P < 0.05 (P < 0.05) was considered for statistical significance.


The mean zone of inhibition of E. faecalis with different pulp-capping materials at 24 h is shown in [Table 1]. The highest zone of inhibition (3.32 ± 0.11 mm) was found in MTA-Angelus, followed by Dycal (2.02 ± 0.46 mm) and Calcicur (1.84 ± 0.92 mm).{Table 1}

The mean zone of inhibition of E. faecalis with different pulp-capping materials post 72 h is displayed in [Table 2]. The maximum zone of inhibition was shown by MTA-Angelus (4.60 ± 0.22 mm), tailed by Dycal (3.48 ± 0.74 mm) and Calcicur (2.90 ± 0.18 mm).{Table 2}

The intergroup comparison of the antimicrobial activity and changes within the pulp-capping material groups was tested using ANOVA and is shown in [Table 3]. A highly significant difference (P < 0.0001) was found.{Table 3}

The comparison between the pulp-capping agents' antimicrobial activity against E. faecalis is shown in [Table 4]. MTA-Angelus and Dycal demonstrated a statistically significant difference (P < 0.001) between the groups. No statistically significant difference was found in the Calcicur group.{Table 4}


Complete removal of infected dentin is of utmost importance for the successful elimination of dental caries. However, for several reasons, some infected dentin may be left within the cavity. The remnant bacteria within the cavity results in secondary caries or pulpal damage postrestoration. Thus, the cavity has to be subjected to antibacterial treatment before completion of restoration. In addition, if complete removal of all the carious dentin in deep lesions results in pulpal exposure, we dentists frequently prefer to leave some carious dentin to protect the pulp and teeth as much as possible. Furthermore, an ideal pulp-capping agent with antibacterial activity should be used to defend the pulp against secondary infection caused by microleakage or remnant bacteria. The most important pulp therapies consist of direct and indirect pulp capping, superficial (partial) pulpotomy, and cervical pulpotomy.[6],[7]

This study showed the highest zone of inhibition in MTA-Angelus, followed by Dycal and Calcicur. The antibacterial effect of MTA was assessed by Parirokh and Torabinejad[8] and demonstrated the antibacterial effect of MTA on few facultative bacteria but showed no effect on strictly anaerobic bacteria. In the past, there have been several debates regarding the antimicrobial efficacy of pulp-capping agents. For example, some trials have shown MTA to be efficacious against E. faecalis, while other trials did not show any significant antimicrobial activity. Estrela et al.[9] did not find any antimicrobial activity of MTA against E. faecalis, but the present study demonstrated the antimicrobial efficacy of MTA against E. faecalis. Asgary et al.[10] found a significantly superior antibacterial effect of calcium hydroxide than MTA. This result is in contradiction to the findings of our study.

Ribeiro et al.[11] suggested that these differences could be due to the procedure used, for example, aerobic and anaerobic incubations. In an aerobic environment, MTA could produce reactive oxygen species which, as mentioned above, will have similar antimicrobial activity as that found with calcium hydroxide. As per Ribeiro et al.,[11] under anaerobic conditions, MTA cannot generate free ions that influence antimicrobial effect on diverse bacterial strains.

Torabinejad et al.[12] did not find the antibacterial effect of MTA against any of the stern anaerobic bacteria. However, our results have demonstrated the antimicrobial activity of MTA under anaerobic condition due to its highly alkaline pH of 12.5.

MTA is biocompatible hydrophilic cement with mechanical properties similar to dentin which can be utilized as a substitute for dentin. It has a positive effect on vital pulpal cells and stimulates the formation of tertiary dentin.[13]

In this study, the zone of inhibition was higher in Dycal than in Calcicur. Lu et al.[14] have demonstrated the antibacterial activity of calcium hydroxide. Under aqueous environment, calcium hydroxide Ca (OH)2 releases hydroxyl ions and this influences its antibacterial activity. Hydroxyl ions are extremely oxidant free radicals that display the highest reactivity with numerous biomolecules. According to Babich and Sinensky,[15] this reactivity is indiscriminate and high, and because of this, the free radical seldom disperses away from its generated site. This indiscriminate action affects the action of mitochondria in cultured cells on cytocompatibility testing.

The results from these in vitro trials suggest that no investigational agent is capable of eliminating all microbial colonies. The increasing knowledge of pulpal use of biocompatible agents and their antimicrobial activity against endodontic pathogens indicates their potential use in dentistry.[16] This in vitro test was conducted to demonstrate the importance of different pulp-capping agents to the practitioners. Thus, an in vitro test is vital to determine the antimicrobial efficacy of pulp-capping agents. The results obtained by the present study displayed that the pulp-capping agents vary in antimicrobial activity by the zone of inhibition.


This trial found that the freshly mixed MTA-Angelus has a significantly superior antimicrobial effect against E. faecalis than Dycal and Calcicur.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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