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Authors are the souls of any journal, and deserve much respect. To publish a journal manuscripts are needed from authors. Authors have a great responsibility for producing facts of their work in terms of number and results truthfully and an individual honesty is expected from authors in this regards. Both ways its true "No authors-No manuscripts-No journals" and "No journals–No manuscripts–No authors". Reviewing a manuscript is also a very responsible and important task of any peer-reviewed journal and to be taken seriously. It needs knowledge on the subject, sincerity, honesty and determination. Although the process of reviewing a manuscript is a time consuming task butit is expected to give one's best remarks within the time frame of the journal.
Salient features of the JCDR: It is a biomedical, multidisciplinary (including all medical and dental specialities), e-journal, with wide scope and extensive author support. At the same time, a free text of manuscript is available in HTML and PDF format. There is fast growing authorship and readership with JCDR as this can be judged by the number of articles published in it i e; in Feb 2007 of its first issue, it contained 5 articles only, and now in its recent volume published in April 2011, it contained 67 manuscripts. This e-journal is fulfilling the commitments and objectives sincerely, (as stated by Editor-in-chief in his preface to first edition) i e; to encourage physicians through the internet, especially from the developing countries who witness a spectrum of disease and acquire a wealth of knowledge to publish their experiences to benefit the medical community in patients care. I also feel that many of us have work of substance, newer ideas, adequate clinical materials but poor in medical writing and hesitation to submit the work and need help. JCDR provides authors help in this regards.
Timely publication of journal: Publication of manuscripts and bringing out the issue in time is one of the positive aspects of JCDR and is possible with strong support team in terms of peer reviewers, proof reading, language check, computer operators, etc. This is one of the great reasons for authors to submit their work with JCDR. Another best part of JCDR is "Online first Publications" facilities available for the authors. This facility not only provides the prompt publications of the manuscripts but at the same time also early availability of the manuscripts for the readers.
Indexation and online availability: Indexation transforms the journal in some sense from its local ownership to the worldwide professional community and to the public.JCDR is indexed with Embase & EMbiology, Google Scholar, Index Copernicus, Chemical Abstracts Service, Journal seek Database, Indian Science Abstracts, to name few of them. Manuscriptspublished in JCDR are available on major search engines ie; google, yahoo, msn.
In the era of fast growing newer technologies, and in computer and internet friendly environment the manuscripts preparation, submission, review, revision, etc and all can be done and checked with a click from all corer of the world, at any time. Of course there is always a scope for improvement in every field and none is perfect. To progress, one needs to identify the areas of one's weakness and to strengthen them.
It is well said that "happy beginning is half done" and it fits perfectly with JCDR. It has grown considerably and I feel it has already grown up from its infancy to adolescence, achieving the status of standard online e-journal form Indian continent since its inception in Feb 2007. This had been made possible due to the efforts and the hard work put in it. The way the JCDR is improving with every new volume, with good quality original manuscripts, makes it a quality journal for readers. I must thank and congratulate Dr Hemant Jain, Editor-in-Chief JCDR and his team for their sincere efforts, dedication, and determination for making JCDR a fast growing journal.
Every one of us: authors, reviewers, editors, and publisher are responsible for enhancing the stature of the journal. I wish for a great success for JCDR."
Thanking you
With sincere regards
Dr. Rajendra Kumar Ghritlaharey, M.S., M. Ch., FAIS
Associate Professor,
Department of Paediatric Surgery, Gandhi Medical College & Associated
Kamla Nehru & Hamidia Hospitals Bhopal, Madhya Pradesh 462 001 (India)
E-mail: drrajendrak1@rediffmail.com
On May 11,2011
Dr. Shankar P.R.
"On looking back through my Gmail archives after being requested by the journal to write a short editorial about my experiences of publishing with the Journal of Clinical and Diagnostic Research (JCDR), I came across an e-mail from Dr. Hemant Jain, Editor, in March 2007, which introduced the new electronic journal. The main features of the journal which were outlined in the e-mail were extensive author support, cash rewards, the peer review process, and other salient features of the journal.
Over a span of over four years, we (I and my colleagues) have published around 25 articles in the journal. In this editorial, I plan to briefly discuss my experiences of publishing with JCDR and the strengths of the journal and to finally address the areas for improvement.
My experiences of publishing with JCDR: Overall, my experiences of publishing withJCDR have been positive. The best point about the journal is that it responds to queries from the author. This may seem to be simple and not too much to ask for, but unfortunately, many journals in the subcontinent and from many developing countries do not respond or they respond with a long delay to the queries from the authors 1. The reasons could be many, including lack of optimal secretarial and other support. Another problem with many journals is the slowness of the review process. Editorial processing and peer review can take anywhere between a year to two years with some journals. Also, some journals do not keep the contributors informed about the progress of the review process. Due to the long review process, the articles can lose their relevance and topicality. A major benefit with JCDR is the timeliness and promptness of its response. In Dr Jain's e-mail which was sent to me in 2007, before the introduction of the Pre-publishing system, he had stated that he had received my submission and that he would get back to me within seven days and he did!
Most of the manuscripts are published within 3 to 4 months of their submission if they are found to be suitable after the review process. JCDR is published bimonthly and the accepted articles were usually published in the next issue. Recently, due to the increased volume of the submissions, the review process has become slower and it ?? Section can take from 4 to 6 months for the articles to be reviewed. The journal has an extensive author support system and it has recently introduced a paid expedited review process. The journal also mentions the average time for processing the manuscript under different submission systems - regular submission and expedited review.
Strengths of the journal: The journal has an online first facility in which the accepted manuscripts may be published on the website before being included in a regular issue of the journal. This cuts down the time between their acceptance and the publication. The journal is indexed in many databases, though not in PubMed. The editorial board should now take steps to index the journal in PubMed. The journal has a system of notifying readers through e-mail when a new issue is released. Also, the articles are available in both the HTML and the PDF formats. I especially like the new and colorful page format of the journal. Also, the access statistics of the articles are available. The prepublication and the manuscript tracking system are also helpful for the authors.
Areas for improvement: In certain cases, I felt that the peer review process of the manuscripts was not up to international standards and that it should be strengthened. Also, the number of manuscripts in an issue is high and it may be difficult for readers to go through all of them. The journal can consider tightening of the peer review process and increasing the quality standards for the acceptance of the manuscripts. I faced occasional problems with the online manuscript submission (Pre-publishing) system, which have to be addressed.
Overall, the publishing process with JCDR has been smooth, quick and relatively hassle free and I can recommend other authors to consider the journal as an outlet for their work."
Dr. P. Ravi Shankar
KIST Medical College, P.O. Box 14142, Kathmandu, Nepal.
E-mail: ravi.dr.shankar@gmail.com
On April 2011 Anuradha
Dear team JCDR, I would like to thank you for the very professional and polite service provided by everyone at JCDR. While i have been in the field of writing and editing for sometime, this has been my first attempt in publishing a scientific paper.Thank you for hand-holding me through the process.
Dr. Anuradha
E-mail: anuradha2nittur@gmail.com
On Jan 2020
Original article / research
Full Version
Comparison of Fracture Resistance of Endodontically Treated Human Mandibular Molars Restored with Paracore Dual-cure Composite and EverX Posterior Composite: An In-vitro Study
Correspondence Address :
Laboni Ghorai,
6, Ram Gopal Ghosh Road, Cossipore, Kolkata-700002, West Bengal, India.
E-mail: dr.labonidey@gmail.com
Introduction: Endodontic treatment is an elective dental procedure that is performed when the dental pulp becomes irreversibly damaged or necrotic due to dental caries or trauma. Considerable loss of coronal tooth structure together with large cavity designs and access cavities compromise the mechanical behaviour of endodontically treated teeth, making them more susceptible to catastrophic fracture. Hence, following endodontic treatment, it is imperative to provide a suitable restorative material to avoid subsequent tooth fracture following occlusal loading.
Aim: To assess and compare the fracture resistance of endodontically treated human mandibular first molars restored with dual-cure composite (Paracore) and newer short fibre-reinforced composite (EverX Posterior) in occlusal (Class-I) cavities.
Materials and Methods: The in-vitro study was performed in January 2023 to February 2023 using 30 freshly extracted sound adult human mandibular first molars (divided in three groups) at Guru Nanak Institute of Dental Sciences and Research, Kolkata, West Bengal, India. A total of 10 intact teeth served as positive controls (Group-1). Class-I access cavity preparation followed by endodontic therapy was performed on the remaining 20 teeth, which were randomly divided into two groups (Group-2 and 3), which were coronally restored with Paracore dual-cure composite and EverX posterior composite, respectively. Teeth were mounted in acrylic resin, and subsequently, measurements of fracture strength were performed using a universal testing machine. Data were analysed statistically using One-way Analysis of Variance (ANOVA), Post-Hoc Tukey, and Chi-square tests, with a p-value of ≤0.05 considered as the level of significance.
Results: The mean fracture resistance values (in kilonewtons) were as follows: Group-1 (1.5750 kN) > Group-3 (1.0450 kN) > Group-2 (0.6350 kN). Group-3 showed a significantly higher mean fracture resistance value (p=0.035) than the other experimental group. The levels of fractures were also evaluated, and a significant difference between the groups was noted (p=0.001), concluding that the frequencies of unfavourable fractures were significantly higher in Group-2 than in the other groups.
Conclusion: Short fibre-reinforced composite (EverX) showed fracture resistance similar to that of a natural tooth and hence can be used as a direct core build-up material to reinforce the remaining tooth structure in endodontically treated teeth.
Core build-up material, Endodontic therapy, Fibre-reinforced composite, Occlusal cavities
Over the past decades, endodontic treatment has been the mainstay for salvaging a pulpally exposed tooth. However, the treatment is considered incomplete until an appropriate post-endodontic coronal restoration is done, as these endodontically treated teeth are generally weaker than sound teeth and are more vulnerable to fracture (1). Trope M et al., believed that endodontically treated teeth are weakened by the loss of tooth structure from caries, preparation of access cavity, and instrumentation of the root canal (2). In addition, the loss of moisture in dentin, age-induced dentinal changes, decreased proprioceptive function, conditioning of radicular dentin with endodontic irrigant and medicament, and the effect of bacterial colonisation on the dentin substrate have been considered the major factors for the loss of resiliency and fracture resistance of endodontically treated teeth (3). Therefore, intracoronal strengthening of these teeth is important, particularly in posterior teeth where the fracture of undermined tooth structure is common with the stress generated by normal masticatory forces. An ideal post-endodontic restoration has the advantages of the preservation of the remaining tooth structure, maintenance of aesthetics and function, and prevention of microleakage (4).
Studies have suggested various types of post-endodontic restorations, which include amalgam restorations, composite materials, cast restorations, and full-coverage crowns. However, amalgam restorations lack adhesion to the tooth structure and promote microcrack propagation under fatigue loading, while full-coverage crowns and cast restorations involve multiple visits and increased cost (5),(6),(7). Hence, composite resin is often preferred by clinicians due to its excellent aesthetic and mechanical properties with the ease of handling (8). However, conventional composites have the inherent drawbacks of polymerisation shrinkage and insufficient fracture resistance (9). These limitations have encouraged researchers to innovate a new generation of composites. ParaCore, a dual-cure composite that has been developed as a core build-up material, has promised to have better fracture resistance compared to conventional composites. Composites reinforced with fibres such as EverX Posterior improve marginal integrity and are reported to have better fracture resistance properties (10),(11).
Since the literature lacks sufficient data regarding the strength and success of these newer composite materials, this in-vitro study was proposed to assess and compare the fracture resistance of endodontically treated human mandibular first molars restored with dual-cure composite (Paracore) and newer short fibre-reinforced composite (EverX Posterior) in occlusal (Class-I) access cavities.
The in-vitro study was performed in January 2023 to February 2023 using 30 freshly extracted sound adult human mandibular first molars. Patients visiting the OPD of Guru Nanak Institute of Dental Sciences and Research, Kolkata, West Bengal, India were examined, and mandibular first molars with sound tooth structure but required extraction due to weak periodontal status, orthodontic, or prosthetic reasons were selected for the study. Since the study was carried out in-vitro, ethical clearance was deemed unnecessary by the ethical committee. The study was conducted in accordance with the principles of the Helsinki Declaration of 1975, as revised in 2000.
Inclusion and Exclusion criteria: Fully erupted teeth with mature apices and sound tooth structure were included in the study. Teeth with open apices, resorption, developmental anomalies, carious lesions, crown or root fractures, severe attrition or abrasion, and previous restorations were excluded from the study.
Study Procedure
Sample size: A total of 30 samples were included, with 10 in each group.
Sample preparation: Following gross debridement of all tooth specimens under running tap water, cleaning of calculus deposits and any attached periodontal tissue was performed using an ultrasonic scaler unit (Biosonic, Coltene Whaledent, Switzerland) and then stored in distilled water at 4°C until further processing. A total of 10 intact teeth were randomly selected and used as positive controls (Group-1). An endodontic access cavity of 3×3 mm dimensions was prepared in each of the remaining 20 teeth using 2.3 mm round and 1.4 mm straight fissure diamond points (SS White, USA) with a water-cooled high-speed air-rotor handpiece (NSK, Japan), and the remnants of pulpal tissue were extirpated using a barbed broach (Dentsply Maillefer, Switzerland). The working length was assessed by subtracting 1 mm from the length obtained by inserting a size 10 K file (Mani Prime Dental Pvt., Ltd.) into each canal until it could be seen at the apical foramen. Root canal instrumentation (Table/Fig 1)a was carried out with sequential ProTaper Gold Nickel Titanium (NiTi) rotary files (Sx, S1, S2, F1) {Dentsply Maillefer, Ballaigues, Switzerland} in a crown-down technique using Glyde {10% carbamide peroxide and 15% Ethylenediaminetetraacetic acid (EDTA), Dentsply Maillefer} as the lubricant. Following each instrumentation, the root canals were recapitulated and adequately irrigated with a 2.5% sodium hypochlorite solution. Subsequently, the canals were dried with absorbent paper points (Dentsply Maillefer, Ballaigues, Switzerland) and obturated with F1 ProTaper Gold gutta-percha points and AH Plus root canal sealer (Dentsply Maillefer, Ballaigues, Switzerland). The gutta-percha was then cleaned up to the level of the canal orifice.
Subsequently, the endodontically treated teeth were randomly divided into two groups: Group-2 and Group-3, with 10 teeth in each group. The teeth were then air-dried, and the bonding agent G-Bond (GC, Japan) was applied in Group-2, while ParaBond (Coltene Whaldent, Switzerland) was applied in Group-3, following the manufacturer’s instructions. They were then light-cured for 20 seconds using an LED light curing equipment (Coltolux LED, Coltene Whaldent, Switzerland) with an intensity of 1400 mW/cm2. All the teeth samples in Group-2 were restored with Paracore dual-cure composite (Table/Fig 1)b, and those in Group-3 were restored with EverX Posterior (Table/Fig 1)c. All the restorations were light-cured for 40 seconds. The final finishing and polishing of the restorations were done with fine-grained composite finishing and polishing discs (Soflex, 3M, Japan).
Fracture testing: For fracture testing, each tooth specimen was vertically mounted 2 mm below the Cementoenamel (CEJ) junction in an auto-polymerised acrylic resin block measuring 25×25×20 mm. Before mounting, a layer of light body elastomeric impression material simulating the periodontal ligament was placed around the root surfaces. Each mounted tooth was then subjected to static loading using a Universal Testing Machine (Table/Fig 2) with a cross-head speed of 0.5 mm/minute, onto the central pit vertically down the long axis of the tooth until tooth fracture occurred. The force required to fracture each tooth was recorded in Kilo-Newton (KN). In addition to the fracture resistance values, the levels of fractures were also evaluated. Fractures limited to the enamel levels can be considered favourable as they can be easily repaired without additional reinforcement. However, when the fracture line extends up to the level of dentine or below the CEJ, it is considered it is considered unfavourable, as more complex restorative procedures may be required or may even result in tooth loss (12).
Statistical Analysis
The data thus obtained were tabulated, and statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) version 16.0. The data were evaluated statistically using One-way ANOVA, Post-Hoc Tukey, and Chi-square tests. The level of significance was fixed at p=0.05, and any value ≤0.05 was considered to be statistically significant.
It was observed that the mean fracture resistance values (in kN) were as follows: Group-1 (1.5750 kN) > Group-3 (1.0450 kN) > Group-2 (0.6350 kN). Group-3 (teeth restored with EverX Posterior) showed a significantly higher mean fracture resistance value than the other experimental group (Group-2: teeth restored with Paracore dual-cure composite) (p=0.035) and a lower mean fracture resistance value than the control group, but the data were not statistically significant (p=0.134) (Table/Fig 3),(Table/Fig 4).
The present study further evaluated the levels of fractures. In both Group-1 and Group-3, the fracture modes were mostly at the level of enamel (favourable), whereas all the fractures in Group-2 were at or below the level of CEJ (unfavourable). Hence, the frequencies of unfavourable fracture patterns varied among different groups, with the highest rate reported in Group-2 (100%), followed by Group-3 (30%), and the lowest in Group-1 (10%). A significant difference in fracture patterns between the groups was noted according to Chi-square analysis (p=0.001), implying that the frequencies of unfavourable fractures were significantly higher in Group-2 compared to other groups (Table/Fig 5).
Clinical experience and research reveal that the tooth becomes weakened due to the reduction of tooth structure during an endodontic procedure, with the access opening only contributing to a reduction of the relative rigidity of the tooth by 5% (13). Hence, an endodontically treated tooth possesses a higher risk of fracture, which has been conclusively stated by several studies (14),(15),(16). Determining the amount of remaining tooth structure for optimum strength against fracture and selecting the type of restorative material are thus the key factors for a successful treatment outcome. Keeping this in mind, the present in-vitro study was designed for the assessment of differences in fracture resistance and comparison of fracture patterns between intact teeth and teeth that underwent restoration with two different coronal restorative materials following endodontic therapy. In the present study, mandibular first molars were selected as they are the most commonly extracted teeth among the endodontically treated posterior teeth (17).
The importance of conservative cavity preparation in minimising the reduction in the strength of the remaining tooth structure is well documented. In comparison to an endodontically treated tooth, an intact tooth is much more resistant to fracture due to the presence of tooth-reinforcing structures such as the roof of the pulp chamber and the marginal ridges (18). In the present study, occlusal Class-I access cavities were prepared because of the importance of conservative access preparations to preserve the original strength of the tooth and to lay emphasis on the evaluation of the efficiency of the newer restorative systems currently available.
The choice of an ideal restorative material that can compensate for the lost coronal tooth structure is considered crucial for the success of post-endodontic restorations (12). Several studies have proven that composite restorative material reinforces the remaining tooth structure (19),(20). This adhesive resin develops both micromechanical retention with the tooth structure and chemical bonds via phosphate esters, which interact with calcium ions present in the tooth. However, reinforcement of the weakened tooth structure is facilitated by the low elastic modulus of composite resin, which enables the transmission of the energy produced by the compressive forces to the adjacent dental structure (21). Although conventional composites have certain drawbacks as a core build-up material, today various newer generation composites have emerged that claim to overcome these limitations of their predecessors and possess superior fracture resistance, eliminating the need for more extensive tooth preparation for the placement of laboratory-aided full-coverage prosthesis, thereby providing potential economic benefits to patients (12).
In the present in-vitro study, the fracture strength of a dual-cure composite (Paracore) and a newer short fibre-reinforced composite (EverX Posterior) were compared. The present study demonstrated that the intact teeth in Group-1 had the highest mean fracture resistance because there was no loss of tooth structure. Among the experimental groups, Group-3 (teeth restored with EverX posterior composite) showed a significantly higher mean fracture resistance value than Group-2 (teeth restored with Paracore dual-cure composite). This can be attributed to the large filler particle size of 0.5-1.6 mm present in EverX Posterior compared to the average filler particle size of 2 μm in Paracore (22),(23). Furthermore, the filler content of Paracore being less than that of EverX Posterior, early crack propagation and decreased fracture resistance are reported to be its major limitations (24). The new fibre-reinforced composite EverX Posterior is a nanohybrid composite impregnated with E-glass fibres, which are known to be resistant to tension and impede crack propagation in the composite mass. The high tensile strength, density, and percentage of elongation of this new-generation composite help to withstand high stresses without fracturing (11).
Similar results were obtained in the study conducted by Kamath AK et al., where the fracture toughness of EverX posterior was comparable to that of a healthy intact tooth, and EverX posterior proved superior to Smart Dentin Replacement (SDR) and 3M Filtek bulk-fill (25). Shah KK et al., in their study on endodontically treated mandibular premolars, showed that Fibre-reinforced composite (EverX Posterior) had the highest resistance to fracture compared with nanohybrid composite (Filtek Z350), which was comparable to that of intact teeth (26).
Several studies have shown that when force is applied along the long axis of the tooth, the force is transmitted fairly uniformly, determining the maximum loads that lead to fracture (27),(28). In the present study, force was also applied vertically at a constant speed using a universal testing machine to evaluate the capacity of the restorative materials used to support vertical tension in areas of high masticatory load.
In addition to the fracture resistance values, the fracture patterns were also evaluated in the present study. In both Group-1 and Group-3, the fracture modes were mostly favourable, suggesting adequate reinforcement in endodontically treated teeth. On the contrary, all the fractures in Group-2 were at or below the level of CEJ, indicating its less reinforcing effect. A significant difference in fracture patterns between the groups was noted (p=0.001), with the frequencies of unfavourable fractures being significantly higher in Group-2 than in the other groups. This result is as per the study conducted by Mudunuri S et al., where the highest proportion of favourable fractures was observed with fibre-reinforced composites compared with the no-fibre group, although the data was not statistically significant (29).
Limitation(s)
One important limitation of the present study is that it was carried out under in-vitro conditions. The in-vitro results cannot be directly extrapolated to a clinical setting such as the oral cavity. Clinically, teeth are exposed to various types of forces, unlike the method of applying a continually increasing load to teeth, as performed in the present study. Hence, more relevant in-vitro test methods should be innovated to simulate the failure mechanisms of restored teeth that are observed clinically. Furthermore, it is necessary to assess and compare fracture resistance and fracture patterns according to the types of restorations performed.
Within the limitations of the present in-vitro study, the highest fracture resistance is exhibited by the short fibre-reinforced composite over the other composite filling materials. Hence, it can be concluded that EverX Posterior, which displayed the maximum reinforcement of the remaining tooth structure, can be used as a direct core buildup material in endodontically treated teeth.
DOI: 10.7860/JCDR/2024/66270.19729
Date of Submission: Jul 04, 2023
Date of Peer Review: Aug 30, 2023
Date of Acceptance: Jun 15, 2024
Date of Publishing: Aug 01, 2024
AUTHOR DECLARATION:
• Financial or Other Competing Interests: None
• Was Ethics Committee Approval obtained for this study? No
• Was informed consent obtained from the subjects involved in the study? No
• For any images presented appropriate consent has been obtained from the subjects. NA
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