Journal of Conservative Dentistry

: 2023  |  Volume : 26  |  Issue : 1  |  Page : 1--2

Microleakage Studies – A Viewpoint

Shishir Singh 
 Department of Conservative Dentistry and Endodontics, Terna Dental College, Navi Mumbai, Maharashtra, India

Correspondence Address:
Dr. Shishir Singh
305/306, St. Annes Apartments, off Palimala Road, Bandra, Mumbai, Maharashtra

How to cite this article:
Singh S. Microleakage Studies – A Viewpoint.J Conserv Dent 2023;26:1-2

How to cite this URL:
Singh S. Microleakage Studies – A Viewpoint. J Conserv Dent [serial online] 2023 [cited 2023 Feb 5 ];26:1-2
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Full Text

Microleakage is one of the most common problems faced in conservative dentistry and endodontics. It happens when microorganisms, their associated toxins, oral fluids, and ionic particles crossover into the dentinal tubules resulting in long-term repercussions for the tooth. Kidd[1] in 1976 defined microleakage as the passage of bacteria, fluids, molecules, or ions between a cavity wall and the restorative material applied to it.

Our specialty has a very interesting bifurcation in the study of microleakage. Microleakage studies are broadly classified into:

Endodontic microleakageRestorative microleakage.

Endodontic microleakage happens at the coronal or apical part of the root canal obturation, each having its own repercussions. Muliyar et al.[2] discussed the role of microleakage in endodontic failures and the importance to address and control it properly to ensure a successful endodontic outcome.

Jafari and Jafari[3] enumerated and discussed methodologies to study endodontic microleakage with their inherent advantages and disadvantages. They are as follows:

Dye penetration studiesFluid filtration/transportation modelDye extraction methodBacterial/endotoxin infiltration methodGlucose penetration model using fluid filtrationProtein microleakage modelRadioisotope penetration modelAnimal experimentsThree-dimensional modelsMicrocomputed tomographyConfocal laser microscopyOptical coherence tomography.

The restorative microleakage happens essentially at the cavosurface or gingival margin of the restoration. The outcome varies depending on the material characteristics, bonding technique, and adhesion chemistry in use. Essentially there are as follows:

Dye leakage studiesMicroleakage studies using a stereo microscopeMicroleakage studies using a scanning electron microscope.

AlHabdan[4] classified microleakage studies using an in vivo (extremely rare) or an in vitro model (most common) and further subclassified them into qualitative and quantitative types. Interestingly, he also mentions a different kind of leakage: nanoleakage that occurs due to fluid movement at the dentin/enamel restoration interphase.

All the methods mentioned coming with their inherent advantages and disadvantages. Rizzante et al.[5] have brought out the benefits of dye penetration and clearing technique viewed stereo microscopically. None of the methods can be considered a gold standard, making such research more challenging and extremely debatable. The relevance of microleakage studies is a big question mark, as standardization is not possible for accuracy, even though there is still a lot of research happening in this direction. Using two or more different microleakage models to study, the same material is a viable option to improve the study outcome and its sensitivity.[6] Combining the scanning electron microscope with fluorescence in situ hybridization/confocal laser microscopy has shown some exciting outcomes.[7],[8]

All the methods are helpful if studies are performed strictly with large sample sizes and proper control groups and if the technique can be standardized. Furthermore, more evaluations of the reliability of the methods are strongly recommended. It is time that the research fraternity comes together and draws out clear-cut protocols in this direction.


1Kidd EA. Microleakage: A review. J Dent 1976;4:199-206.
2Muliyar S, Shameem KA, Thankachan RP, Francis PG, Jayapalan CS, Hafiz KA. Microleakage in endodontics. J Int Oral Health 2014;6:99-104.
3Jafari F, Jafari S. Importance and methodologies of endodontic microleakage studies: A systematic review. J Clin Exp Dent 2017;9:e812-9.
4AlHabdan AA. Review of microleakage evaluation tools. J Int Oral Health 2017;9:141-5.
5Rizzante FA, Sedky RA, Furuse AY, Teich S, Ishikiriama SK, Mendonça G. Validation of a method of quantifying 3D leakage in dental restorations. J Prosthet Dent 2020;123:839-44.
6Jafari F, Rahimi S, Shahi S, Jafari S. Endodontic microleakage studies: Correlation among different methods, clinical relevance, and potential laboratory errors. Minerva Stomatol 2017;66:169-77.
7Schaudinn C, Carr G, Gorur A, Jaramillo D, Costerton JW, Webster P. Imaging of endodontic biofilms by combined microscopy (FISH/cLSM – SEM). J Microsc 2009;235:124-7.
8Shakoori AR. Fluorescence in situ hybridization (FISH) and its applications. Chromosome Struct Aberrations 2017:343-67.