Methodologies for assessment of apical and coronal leakage of endodontic filling materials: a critical review

Abstract

Keywords: dye dilution technique; dyes; filtration. IntroductionMicroorganisms present inside root canals may remain active in the dentinal tubules even after vigorous chemicalmechanical preparation. Thus, perfect apical sealing is desirable to prevent the remaining bacteria and their endotoxins from reaching the root apex (1,2). Apical leakage is considered to be a common cause for endodontic therapy failure, and is influenced by many variables such as different filling techniques, the physical and chemical properties of sealers and the presence or absence of a smear layer (1,3). In coronal leakage, the canal may be recontaminated in various ways such as contact between the oral bacterial flora and root canal tubule inlets. However, it most frequently occurs as a result of loss of temporary filling, or inadequate endodontic filling or crown sealing (4,5).According to Timpawat et al. (6), endodontic sealers are used to eliminate the interface between the gutta-percha and the dentinal walls. Leakage may, however, occur at the interfaces between the sealer and dentin, sealer and gutta-percha and in spaces within the sealer itself. Thus, the quality of the filling depends largely on the sealing capacity offered by sealers (7,8).Methodologies in vitro are used to estimate sealing quality, generally by measuring microleakage that allows the tracer agent to penetrate the filled canal. Commonly used tracers are dyes, radioisotopes, bacteria and their products, such as endotoxins. Bacteria used as tracers most closely approximate what happens clinically in terms of leakage (9-11). Other methodologies, such as fluid filtration and dye extraction methods have also been used, their main advantage being high reproducibility (1,(12)(13)(14).The aim of this review was to critically analyze the various methodologies reported in the literature for assessing root canal sealing capacity. Apparently, they are not standardized, which makes it difficult to compare the results obtained when different methodologies are used, even though the same substrate is being assessed. Literature ReviewAlthough there are many leakage studies, there is no consensus about the endodontic sealer and core material sealing capacities. One of the reasons is that investigations do not use a standardized methodology and this frequently

A comparative study of apical microleakage of different root canal sealers by apical dye penetration

“…Among them linear measurement of tracer dye penetration technique is most frequently used. 15 In this study we compare, in vitro, sealing ability of four different root canal sealers; Acroseal (Septodont, Saint-Maur, France), AH Plus (Dentsply De Trey.GmbH, Konstanz, Germany), Endoflas-FS (Sanlor and CIA S. en C.S. Cali Colombia) and Endomethasone N (Septodont, Saint Maur, France) by the measurement of linear dye penetration using stereomicroscope (Olympus, USA).…”

Coronal sealing ability of different sealers on teeth obturation and the effectiveness of two different obturation techniques

“…The failure of various sealers may be due to their chemical composition and physical properties (such as adhesiveness, dimensional stability, flow, solubility). 8 Generally, groups of AH26 sealer showed significantly less coronal leakage in comparison to groups of ZOE sealer especially Discussion when canals obturated by obtura II although the result was non significant in group obturated by cold lateral compaction but gives better sealing. This result some what in agreement with some author's studies [18][19][20] as they showed that the epoxy resin sealer had better sealing ability than ZOE sealer and the most efficient adhesion between sealer and root canal walls achieved when epoxy resin sealer was used.…”

“…15 Many in vitro methods have been used to evaluate the sealing qualities of endodontic filling materials, but most studies have used methylene blue dye because it is inexpensive, easy to manipulate, has a high degree of staining, very small molecular weight even lower than that of bacterial toxins, the same leakage as butyric acid and shows a deeper penetration than other dyes therefore was used in this study. 5,8,16 Air entrapped within the root canal filling material or inside the root canal system may inhibit penetration of dye into the pores and gaps. Oliver and Abbott stated that after centrifugation at 3,000 rpm for 5 minutes, dye penetration was 91.7%; dye penetration by passive immersion was 20.7%.…”

“…6,7 Studies showed that leakage may occur at the interfaces between the sealer and dentin, sealer and guttapercha and in spaces within the sealer, thus the quality of the filling depends largely on the sealing ability of the sealers. 8 Kopper et al 9 showed that the resin-based root canal sealers presented lesser coronal leakage than zinc oxide -eugenole based sealers. Many different obturation techniques have been introduced ranging from solid core filling of gutta percha to its softening techniques with either solvents or heat in the attempt to secure the best possible obturation of the endodontic space and to increase the quality of sealing.…”

Comparison of Pro Root Mineral Trioxide Aggregate and Calcium Enriched Mixture Cement Microleakage as Root End Filling Material: An in Vitro Analysis of Dye Penetration

“…There are different methods for evaluating endodontic materials microleakage such as bacteria leakage, dye or ink, radio isotopes, electrochemical and fluid filtration techniques (6). However, it seems to be that dye penetration is the easiest and most popular method (1, 6).…”