Journal of Conservative Dentistry
Home About us Editorial Board Instructions Submission Subscribe Advertise Contact e-Alerts Login 
Users Online: 84
Print this page  Email this page Bookmark this page Small font sizeDefault font sizeIncrease font size
 


 
Table of Contents   
ORIGINAL ARTICLE  
Year : 2016  |  Volume : 19  |  Issue : 6  |  Page : 536-540
Histological evaluation of mineral trioxide aggregate and enamel matrix derivative combination in direct pulp capping: An in vivo study


1 Department of Conservative Dentistry and Endodontics, St. Joseph Dental College and Hospital, Eluru, Andhra Pradesh, India
2 Department of Conservative Dentistry and Endodontics, Lenora Institute of Dental Sciences, Rajahmundry, Andhra Pradesh, India
3 Department of Conservative Dentistry and Endodontics, Sibar Institute of Dental Sciences, Guntur, Andhra Pradesh, India
4 Department of Oral and Maxillofacial Pathology, Sibar Institute of Dental Sciences, Guntur, Andhra Pradesh, India
5 Department of Periodontics, St. Joseph Dental College and Hospital, Eluru, Andhra Pradesh, India

Click here for correspondence address and email

Date of Submission07-Jul-2016
Date of Decision02-Sep-2016
Date of Acceptance20-Oct-2016
Date of Web Publication14-Nov-2016
 

   Abstract 

Aim: The aim of this study is to evaluate the response of human pulp tissue to mineral trioxide aggregate (MTA), Emdogain (EMD), and combination of MTA/EMD.
Materials and Methods: This study was performed on sixty intact first and second premolars of human maxillary and mandibular teeth. A standard pulpal exposure was done on all the teeth and was divided into three groups of twenty teeth each and was capped with MTA, EMD, and MTA/EMD combination. The final restoration was done with resin-modified glass ionomer cement. The teeth were then extracted on the 15th or 45th day and histological evaluation done.
Results: Differences in inflammatory response and thickness of dentin bridge formation of the exposed pulp to the three different groups were statistically evaluated using Chi-square and Mann–Whitney tests and were found to be significant. No significant difference was found between MTA/EMD and MTA in terms of calcified bridge formation and pulp inflammatory response to the capping materials.
Conclusions: MTA and MTA/EMD combination produced a better quality hard tissue response compared with the use of EMD.

Keywords: Calcific bridge; direct pulp capping; enamel matrix derivative; histological evaluation; inflammatory response; mineral trioxide aggregate

How to cite this article:
Bollu IP, Velagula L D, Bolla N, Kumar K K, Hari A, Thumu J. Histological evaluation of mineral trioxide aggregate and enamel matrix derivative combination in direct pulp capping: An in vivo study. J Conserv Dent 2016;19:536-40

How to cite this URL:
Bollu IP, Velagula L D, Bolla N, Kumar K K, Hari A, Thumu J. Histological evaluation of mineral trioxide aggregate and enamel matrix derivative combination in direct pulp capping: An in vivo study. J Conserv Dent [serial online] 2016 [cited 2017 Mar 29];19:536-40. Available from: http://www.jcd.org.in/text.asp?2016/19/6/536/194031

   Introduction Top


The goal of restorative therapy is not only to restore the tooth to proper form and function but also aims to preserve the pulp vitality. Vital pulp has several important functions which include induction, formation, nutrition, defense, and sensation. Vital pulp possesses the capacity to produce secondary, tertiary, and reparative dentin to the external stimuli.[1],[2]

Pulp exposure can occur due to caries process, trauma or accidentally in an operative procedure. In response to these stimuli, at the exposure site, a new odontoblast-like cells are recruited and differentiated to synthesize reparative dentin.[1],[3],[4]

The objectives of direct pulp capping (DPC) are to seal the pulp against bacterial penetration, to encourage the pulp to wall of the exposure by forming a dentine bridge and to maintain healthy pulp tissue.[1],[4]

A wide variety of materials has been advised for the DPC.[5] Many studies have indicated that calcium hydroxide (Ca[OH]2) and mineral trioxide aggregate (MTA) are the gold standard materials for DPC.[6],[7]

However, Ca(OH)2 have certain limitations such as the presence of tunnels in the dentine barrier, pulp chamber obliteration, solubility in oral fluids, degradation after acid etching, and lack of adhesion.[8]

The performance of MTA as a DPC agent was evaluated by several authors and found to be significantly superior than Ca(OH)2.[7],[9] Although several case reports and clinical studies have evaluated the effect of MTA for pulp capping, very few histologic studies have been conducted.[8],[9],[10],[11]

On the other hand, Emdogain (EMD) enamel matrix derivative induces mesenchymal cell differentiation imitating odontogenesis.[12] Therefore, EMD serves as a biologically active pulp capping agent specifically inducing pulpal repair and hard tissue formation.[13]

Hence, the purpose of this study was to evaluate the histological response of pulp tissue to MTA, EMD, and combination of MTA/EMD.


   Materials and Methods Top


This study design was approved by the Institutional Ethical Committee. Sixty healthy human premolar teeth scheduled to be extracted for orthodontic treatment were selected from twenty individuals ranging from 15 to 25 years old. The subjects and parents were explained about the clinical procedures and risks associated with the study and written consents were obtained. Inclusion criteria were subjects having at least three premolar teeth with closed apices that needed extraction for orthodontic reasons. The teeth with pulp involvement, developmental defects, and no response to vitality tests were excluded from the study.

Operative procedure

All the clinical procedures were performed by the same author. The teeth were anesthetized with Lignox 2% A (lignocaine with adrenaline 1:80,000, Indoco Remedies Ltd., Mumbai, India) and occlusal cavities were prepared by sterile diamond burs (No. 330 Diatech) at high speed under rubber dam. A standard pulpal exposure of 1–1.5 mm was made, and hemostasis was obtained with cotton moistened with sterile saline. The exposed area was capped with MTA (ProRoot MTA, Dentsply Caulk, Milford, DE, USA), EMD (Straumann AB, Sweden), and combination of MTA/EMD. After placing MTA, a wet cotton pellet was placed over MTA, till its initial set and restored with resin-modified glass ionomer cement (RMGIC) (GC Fuji II LC, GC Corporation Tokyo, Japan). EMD gel was placed on the exposed site and restored with RMGIC. A drop of EMD was placed over exposed site after that MTA was mixed according to manufacturer's instructions, and the cavities were restored with RMGIC.

Thirty teeth (ten teeth per group) were extracted atraumatically at 15 and 45 days, respectively. After extraction, the apical third of all teeth were sectioned and fixed in 10% formalin. The teeth were decalcified and then dehydrated in ascending grades of N-butyl alcohol and embedded in paraffin. Serial sections of 4 µm were cut using soft tissue microtome (Microm HM 340E, Thermo Scientific, India) in a buccolingual plane and stained with hematoxylin and eosin. The sections were blindly evaluated by oral pathologists and calibrated according to the criteria given by Cox et al.[14]

Inflammatory cell response

Grade 1: Absent or very few inflammatory cells. Grade 2: Mild or average number <10 inflammatory cells. Grade 3: Severe inflammatory lesion appearing as an abscess or dense infiltrate involving one-third or more of the coronal pulp. Grade 4: Completely necrotic pulp.

Dentine bridge formation

Grade 1: Presence of a calcific bridge directly adjacent to some portion of the medicament interface. Grade 2: Presence of a calcific bridge distant from the medicament interface. Grade 3: No evidence of any calcific bridge formation in any sections.

The scores were subjected to Chi-square test for data analysis and statistically analyzed through SPSS 13.0 version (SPSS Inc., Chicago, USA). P < 0.05 was established to state the statistically significant difference.


   Results Top


Histological evaluation

The specimens with MTA showed thin strands of collagen fibers, dilated blood vessels, newly formed odontoblast cells with mild inflammatory cell infiltrate and thin calcific bridge after 15 days [Figure 1]a. After 45 days, the specimens with MTA showed the formation of thick calcific bridge without any inflammatory cell infiltrate [Figure 1]d.
Figure 1: Photomicrographic images of histologic sections. (a-c) Pulpal response of mineral trioxide aggregate, Emdogain, mineral trioxide aggregate/Emdogain combination after 15 days' time interval, respectively. (d-f) Pulpal response of mineral trioxide aggregate, EMD, mineral trioxide aggregate/Emdogain combination after 45 days' time interval, respectively

Click here to view


The specimens with EMD showed bundles of collagen fibers and dilated blood vessels with areas of calcified material [Figure 1]b. After 45 days, the EMD formed calcific material present above the pulpal floor with numerous new blood vessels. Chronic inflammatory cell infiltration predominantly lymphocytes were also observed [Figure 1]e. Few specimens showed moderate to severe inflammatory cell infiltrate after 15 and 45 days.

The specimens with a combination of MTA and EMD showed the formation of new odontoblasts, collagen fibers, and numerous new blood vessels with areas of calcification barrier after 15 days [Figure 1]c. The same combination after 45 days showed prominent odontoblastic layer and pulp chamber with collagen fibers and areas of calcification [Figure 1]f.

The inflammatory response between the study materials concluded that EMD showed more inflammatory response compared to other groups after 15 and 45 days which was statistically significant [Table 1].
Table 1: Statistical analysis of samples showing inflammatory cell response

Click here to view


The calcific bridge formation was prominent in MTA and MTA/EMD combination when compared with EMD after 15 and 45 days which was statistically significant. No significant difference was found between MTA and MTA/EMD [Table 2].
Table 2: Statistical analysis of samples showing calcific bridge formation

Click here to view



   Discussion Top


In spite of a wide research made in the field of pulp physiology, there is no single gold standard regimen for DPC that can achieve reliable and predictable goals of preserving tooth vitality and tooth function. The ideal pulp capping material should be biocompatible, prevent bacterial leakage provide a biological seal and stimulate dentin bridge formation.[1]

Different authors proposed various criteria to characterize the success of DPC. Tooth that is asymptomatic, responds to sensibility tests and has normal radiographic appearance after pulp capping is said to be clinically successful by many authors. However, several authors agree that clinical criterion is insufficient to evaluate the long-term prognosis of pulp capping procedures. The teeth in which healing is complicated by inflammation are impossible to clinically diagnose. Therefore, a critical evaluation of the results can only be made histologically.[1],[6],[15]

In the present study, the teeth were extracted after 15 and 45 days to observe the early as well as advanced pulpal response.[4],[12],[16] Clinical studies have demonstrated induction of an early calcific tissue formation with MTA after 1 and 2 weeks.[4],[6],[9] Studies suggest that mild inflammation of pulp with MTA is due to high alkalinity and is a reversible process.[2],[4],[7],[8],[9] MTA induces dentin bridge formation, remineralization, and production of transforming growth factor-β1 due to the bioactivity.[4],[6],[9] Paranjpe et al. in a cell culture study observed an upregulation of important odontogenic genes such as osteocalcin (OCN) and dentin sialoprotein (DSP) and also increased secretion of vascular endothelial growth factor when MTA placed in direct contact with dental pulp cells.[17] Several authors believe calcific bridge formation of MTA is similar to Ca(OH)2 along with good sealing properties and biocompatibility.[9]In vivo studies showed, less tunnel defects, thicker dentin bridge formation, and less inflammation with MTA when compared with traditionally used Ca(OH)2.[4],[7],[9]

In the present study, calcific bridge with mild inflammation was observed in teeth that were capped with MTA. Results of the present study were in corroboration with the previous studies regarding the pulpal response of MTA after 15 and 45 days.[4],[6],[7],[8],[9]

EMD contains amelogenin and enamelin, is used for treating periodontitis to induce cementogenesis.[18] In an in vivo study conducted in dog teeth concluded that EMD is effective in periodontal regeneration.[19] Nakamura et al. have observed reparative dentin formation by EMD on pig incisors.[12] Olsson et al. in their histological study capped experimentally exposed human pulp with EMD (with propylene glycol vehicle) observed formation of thick dentin bridge and fewer postoperative symptoms after 12 weeks when compared to Dycal.[13]

In the present study, thin and irregular dentin bridge were formed and few specimens showed moderate to severe inflammation with EMD this can be due to the presence of acetic acid and direct contact of RMGIC with the exposed pulp. Darwish et al. have stated that jelly-like consistency of EMD could allow direct contact between the glass ionomer base and the exposed pulpal tissues inducing further pulpal inflammation.[18] He et al. observed that EMD promotes the proliferation and differentiation of MC3T3-E1 cells and inhibits osteoclastogenesis and osteoclast function by stimulating the expression of osteoprotegerin.[19] Weishaupt et al. observed that EMD stimulates osteoblasts and increases the expression of specific mineralization markers like DSP.[20]

In the present study, thick uniform calcific barrier with minimal or no inflammatory response was observed with MTA/EMD specimens. Results of the present study were in corroboration with the results of the histomorphometric and microcomputed tomography analysis conducted by Al-Hezaimi et al. observed dentin bridge formation with no tunnel defects after 4 months in baboon teeth when capped with combination of MTA. The formation of atubular osteodentin was noticed with this hybrid approach of pulp capping procedure.[21]

Min et al., by reverse transcriptase polymerase chain reaction found higher level of alkaline phosphatase activity, upregulation of DSP and bone sialoprotien (BSP) with MTA/EMD treated cells than MTA-treated cells. DSP and BS are noncollagenous proteins synthesized during odontogenesis that are secreted into dentin extracellular matrix. Increased mineralization was found with MTA/EMD treated on the 7th day than MTA-treated cells when stained for calcium deposits with Alzarin red.[22]

The presence of inflammatory cells in pulps capped with MTA and MTA/EMD may also result from the restoration of the cavity with RMGIC. Microleakage leads to ingress of bacteria which may increase the pulpal inflammation.[1] RMGIC has good sealing properties and is recommended as material of choice in restoring teeth for vital pulp therapy.[23] Similar to the current study, many in vivo and animal studies used RMGIC as final restoration over MTA, EMD, and MTA/EMD.[4],[12],[21]

The histologic data of the present study demonstrated, a thick calcific barrier surrounded by well-organized odontoblastic layer and less or minimal inflammation in teeth capped with MTA and MTA/EMD specimens whereas teeth that were capped with EMD formed focal areas of calcific bridge with moderate inflammation. Some of the EMD specimens failed to form a calcific bridge and had moderate to severe inflammation after 45 days. Garrocho-Rangel et al. and Kiatwateeratana also failed to observe improvement in the hard tissue barrier formation in a randomized controlled clinical trial when EMD was used as DPC agent and partial pulpotomy procedures respectively in primary molars.[24],[25]

Limitations

This histologic study did not emphasize on nature and type of dentin bridge formed. The study was done over a short-time period and teeth were healthy and free of caries. Therefore, future research should be aimed to evaluate the quality of dentin bridge with large sample size, extended time period, and pulp response on carious affected teeth.


   Conclusions Top


Within the limitations and based on the results of the present histologic study, MTA and the synergistic effect of MTA and EMD induces calcific barrier and less inflammatory response when placed on pulp exposure site. Further research is needed to support these findings.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
   References Top

1.
Asgary S, Ahmadyar M. Vital pulp therapy using calcium-enriched mixture: An evidence-based review. J Conserv Dent 2013;16:92-8.  Back to cited text no. 1
[PUBMED]  Medknow Journal  
2.
Iwamoto CE, Adachi E, Pameijer CH, Barnes D, Romberg EE, Jefferies S. Clinical and histological evaluation of white ProRoot MTA in direct pulp capping. Am J Dent 2006;19:85-90.  Back to cited text no. 2
    
3.
Sloan AJ, Waddington RJ. Dental pulp stem cells: What, where, how? Int J Paediatr Dent 2009;19:61-70.  Back to cited text no. 3
    
4.
Parolia A, Kundabala M, Rao NN, Acharya SR, Agrawal P, Mohan M, et al. A comparative histological analysis of human pulp following direct pulp capping with Propolis, mineral trioxide aggregate and Dycal. Aust Dent J 2010;55:59-64.  Back to cited text no. 4
    
5.
Qureshi A, Soujanya E, Nandakumar, Pratapkumar, Sambashivarao. Recent advances in pulp capping materials: An overview. J Clin Diagn Res 2014;8:316-21.  Back to cited text no. 5
    
6.
Okiji T, Yoshiba K. Reparative dentinogenesis induced by mineral trioxide aggregate: A review from the biological and physicochemical points of view. Int J Dent 2009;2009:464280.  Back to cited text no. 6
    
7.
Eskandarizadeh A, Shahpasandzadeh MH, Shahpasandzadeh M, Torabi M, Parirokh M. A comparative study on dental pulp response to calcium hydroxide, white and grey mineral trioxide aggregate as pulp capping agents. J Conserv Dent 2011;14:351-5.  Back to cited text no. 7
[PUBMED]  Medknow Journal  
8.
Abarajithan M, Velmurugan N, Kandaswamy D. Management of recently traumatized maxillary central incisors by partial pulpotomy using MTA: Case reports with two-year follow-up. J Conserv Dent 2010;13:110-3.  Back to cited text no. 8
[PUBMED]  Medknow Journal  
9.
Parirokh M, Torabinejad M. Mineral trioxide aggregate: A comprehensive literature review – Part III: Clinical applications, drawbacks, and mechanism of action. J Endod 2010;36:400-13.  Back to cited text no. 9
    
10.
Mittal S, Kumar T, Mittal S, Sharma J. Internal root resorption: An endodontic challenge: A case series. J Conserv Dent 2014;17:590-3.  Back to cited text no. 10
  Medknow Journal  
11.
Rudagi KB, Rudagi B. One-step apexification in immature tooth using grey mineral trioxide aggregate as an apical barrier and autologus platelet rich fibrin membrane as an internal matrix. J Conserv Dent 2012;15:196-9.  Back to cited text no. 11
[PUBMED]  Medknow Journal  
12.
Nakamura Y, Hammarström L, Matsumoto K, Lyngstadaas SP. The induction of reparative dentine by enamel proteins. Int Endod J 2002;35:407-17.  Back to cited text no. 12
    
13.
Olsson H, Davies JR, Holst KE, Schröder U, Petersson K. Dental pulp capping: Effect of emdogain gel on experimentally exposed human pulps. Int Endod J 2005;38:186-94.  Back to cited text no. 13
    
14.
Cox CF, Sübay RK, Suzuki S, Suzuki SH, Ostro E. Biocompatibility of various dental materials: Pulp healing with a surface seal. Int J Periodontics Restorative Dent 1996;16:240-51.  Back to cited text no. 14
    
15.
Woehrlen AE Jr. Evaluation of techniques and materials used in pulpal therapy based on a review of the literature: Part I. J Am Dent Assoc 1977;95:1154-8.  Back to cited text no. 15
    
16.
Kakarla P, Avula JS, Mellela GM, Bandi S, Anche S. Dental pulp response to collagen and pulpotec cement as pulpotomy agents in primary dentition: A histological study. J Conserv Dent 2013;16:434-8.  Back to cited text no. 16
[PUBMED]  Medknow Journal  
17.
Paranjpe A, Zhang H, Johnson JD. Effects of mineral trioxide aggregate on human dental pulp cells after pulp-capping procedures. J Endod 2010;36:1042-7.  Back to cited text no. 17
    
18.
Darwish SS, Abd El Meguid SH, Wahba NA, Mohamed AA, Chrzanowski W, Abou Neel EA. Root maturation and dentin-pulp response to enamel matrix derivative in pulpotomized permanent teeth. J Tissue Eng 2014;5:1-12.   Back to cited text no. 18
    
19.
He J, Jiang J, Safavi KE, Spångberg LS, Zhu Q. Emdogain promotes osteoblast proliferation and differentiation and stimulates osteoprotegerin expression. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;97:239-45.  Back to cited text no. 19
    
20.
Weishaupt P, Bernimoulin JP, Trackman P, Hägewald S. Stimulation of osteoblasts with Emdogain increases the expression of specific mineralization markers. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;106:304-8.  Back to cited text no. 20
    
21.
Al-Hezaimi K, Al-Tayar BA, Bajuaifer YS, Salameh Z, Al-Fouzan K, Tay FR. A hybrid approach to direct pulp capping by using Emdogain with a capping material. J Endod 2011;37:667-72.  Back to cited text no. 21
    
22.
Min KS, Yang SH, Kim EC. The combined effect of mineral trioxide aggregate and enamel matrix derivative on odontoblastic differentiation in human dental pulp cells. J Endod 2009;35:847-51.  Back to cited text no. 22
    
23.
Murray PE, Windsor LJ, Smyth TW, Hafez AA, Cox CF. Analysis of pulpal reactions to restorative procedures, materials, pulp capping, and future therapies. Crit Rev Oral Biol Med 2002;13:509-20.  Back to cited text no. 23
    
24.
Garrocho-Rangel A, Flores H, Silva-Herzog D, Hernandez-Sierra F, Mandeville P, Pozos-Guillen AJ. Efficacy of EMD versus calcium hydroxide in direct pulp capping of primary molars: A randomized controlled clinical trial. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107:733-8.  Back to cited text no. 24
    
25.
Kiatwateeratana T, Kintarak S, Piwat S, Chankanka O, Kamaolmatyakul S, Thearmontree A. Partial pulpotomy on caries-free teeth using enamel matrix derivative or calcium hydroxide: A randomized controlled trial. Int Endod J 2009;42:584-92.  Back to cited text no. 25
    

Top
Correspondence Address:
Indira Priyadarshini Bollu
Department of Conservative Dentistry and Endodontics, St. Joseph Dental College, Duggirala, Eluru, West Godavari - 534 003, Andhra Pradesh
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0972-0707.194031

Rights and Permissions


    Figures

  [Figure 1]
 
 
    Tables

  [Table 1], [Table 2]



 

Top
 
 
 
  Search
 
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Email Alert *
    Add to My List *
* Registration required (free)  
 


    Abstract
   Introduction
    Materials and Me...
   Results
   Discussion
   Conclusions
    References
    Article Figures
    Article Tables

 Article Access Statistics
    Viewed380    
    Printed10    
    Emailed0    
    PDF Downloaded93    
    Comments [Add]    

Recommend this journal