: 2022  |  Volume : 34  |  Issue : 3  |  Page : 141--142

Endodontic research: Asking the right questions in the right way

Nandini Suresh 
 Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Meenakshi Ammal Dental College, Meenakshi Academy of Higher Education and Research, Chennai, Tamil Nadu, India

Correspondence Address:
Dr. Nandini Suresh
Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Meenakshi Ammal Dental College, Meenakshi Academy of Higher Education and Research, Chennai, Tamil Nadu

How to cite this article:
Suresh N. Endodontic research: Asking the right questions in the right way.Endodontology 2022;34:141-142

How to cite this URL:
Suresh N. Endodontic research: Asking the right questions in the right way. Endodontology [serial online] 2022 [cited 2022 Nov 26 ];34:141-142
Available from: https://www.endodontologyonweb.org/text.asp?2022/34/3/141/357698

Full Text

“We cannot solve our problems with the same thinking we used when we created them”

–Albert Einstein

The thirst for new knowledge combined with the increase in the number of postgraduate students in the branch of Conservative Dentistry and Endodontics has led to a substantial increase in the number of Endodontic research projects. Online system of the submission process as well as ease of formatting the manuscript and references have made the submission of an article just a click away. These factors have cumulated to a steady increase in the submission of articles to the Endodontology journal. However, to sustain the quality of articles published, the editorial team has to rigorously screen the manuscripts. Lack of robust rationale, poor methodological designs, repetition of previous work, and articles not drafted according to author instructions are a few concerns that lead to desk rejection of the manuscripts.

The need of the hour is to assess the question, “What are the current research needs in Endodontics?”. Addressing a relevant novel research question and conducting the experiments in an appropriate method is of pivotal importance. Few research topics endure rigorous deliberation during the initial screening of submissions such as (a) sealability in endodontics, (b) smear layer removal, and (c) fatigue testing of rotary files, to name a few. Laboratory-based studies must be designed to reduce confounders and to develop reliable well-controlled models. At this juncture, let us explore an example of one such research topic. The clinical implication of studies on sealability in endodontics is questionable and has a long controversial history, which was brought into light by the defining landmark article by Wu and Wesselink.[1],[2] It has been noted that sealability testing experiments are nonreproducible and produce highly variable results.[3] Linear and volumetric dye penetration is one of the most common techniques used and factors such as (a) method of sectioning, (b) selection of dye, and (c) air entrapment in the canal can affect the outcome of these studies.[4]

Numerous other techniques such as fluid transport model, glucose leakage model, culture techniques to detect bacterial penetration, dye extraction and dissolution method, protein microleakage assessment, electrochemical microleakage assessment, as well as radioisotope penetration have been established in endodontic literature.[4] However, the results obtained from these studies could be variable with inherent flaws and are not clinically translatable. For example, the compositional differences of the electrolyte, electrode type, distance, and thickness as well as the electrical conductivity of the ionic solution can affect the outcome of the electrochemical microleakage assessment methods. The use of calcium as an isotope shows increased affinity to tooth structure or restorative materials as well as the size of the isotopes allows its passage through tooth structure resulting in misinterpretation of leakage and measurement errors.[3]

The other major confounder is the root canal anatomy which might influence the result of sealability studies. Thus, the use of paired contralateral teeth from the same patient and to limit experimental groups has been suggested.[5] Bacterial microleakage has been usually assessed using dual-chamber method, detecting microbes using a scanning electron microscope or using a polymerase chain reaction.[6] The use of histological controls to complement bacteriological leakage (two-chamber model) studies is advised.[7] However, a poor correlation has been reported between the microbial and other leakage tests and provides variable results.

In summary, the editorial team emphasizes that the researchers should focus on research that is vital and can make an impact in endodontic literature. Choosing the appropriate methods that can correlate/translate clinically is of pivotal importance. Innovative, well-validated, and well-controlled research is to be considered which will be beneficial for the patients.


1Oliver CM, Abbott PV. Correlation between clinical success and apical dye penetration. Int Endod J 2001;34:637-44.
2Wu MK, Wesselink PR. Endodontic leakage studies reconsidered. Part I. Methodology, application and relevance. Int Endod J 1993;26:37-43.
3Editorial Board of the Journal of Endodontics. Wanted: A base of evidence. J Endod 2007;33:1401-2.
4Jafari F, Jafari S. Importance and methodologies of endodontic microleakage studies: A systematic review. J Clin Exp Dent 2017;9:e812-9.
5De-Deus G. Research that matters – Root canal filling and leakage studies. Int Endod J 2012;45:1063-4.
6Savadkouhi ST, Bakhtiar H, Ardestani SE. In vitro and ex vivo microbial leakage assessment in endodontics: A literature review. J Int Soc Prev Community Dent 2016;6:509-16.
7Rechenberg DK, Thurnheer T, Zehnder M. Potential systematic error in laboratory experiments on microbial leakage through filled root canals: An experimental study. Int Endod J 2011;44:827-35.