In vitro physicochemical characterization of five root canal sealers and their influence on an ex vivo oral multi‐species biofilm community

Abstract

Aim: To evaluate the physicochemical properties of five root canal sealers and assess their effect on an ex vivo dental plaque-derived polymicrobial community. Methodology: Dental plaque-derived microbial communities were exposed to the sealers (AH Plus [AHP], GuttaFlow Bioseal [GFB], Endoseal MTA [ESM], Bio-C sealer [BCS] and BioRoot RCS [BRR]) for 3, 6 and 18 h. The sealers' effect on the biofilm biomass and metabolic activity was quantified using crystal violet (CV) staining and MTT assay, respectively. Biofilm community composition and morphology were assessed by denaturing gradient gel electrophoresis (DGGE), 16S rRNA sequencing and scanning electron microscopy. The ISO6876:2012 specifications were followed to determine the setting time, radiopacity, flowability and solubility. Obturated acrylic teeth were used to assess the sealers' effect on pH. Surface chemical characterization was performed using SEM with coupled energy-dispersive spectroscopy. Data normality was assessed using the Shapiro-Wilk test. One-way anova and Tukey's tests were used to analyze data from setting time, radiopacity, flowability and solubility. Two-way anova and Dunnett's tests were used for the data analysis from CV, MTT and pH. 16S rRNA sequencing data were analyzed for alpha (Shannon index and Chao analysis) and beta diversity (Bray-Curtis dissimilarities). Differences in community composition were evaluated by analysis of similarity (p < .05). Results: The sealers significantly influenced microbial community composition and morphology. All sealers complied with ISO6876:2012 requirements for setting time, radiopacity and flowability. Although only AHP effectively reduced the biofilm biomass, all sealers, except BRR, reduced biofilm metabolic activity. Conclusion: Despite adequate physical properties, none of the sealers tested prevented biofilm growth. Significant changes in community composition were observed. If observed in vivo, these changes could affect intracanal microbial survival, pathogenicity and treatment outcomes.

Avaliação da solubilização e rugosidade superficial de três cimentos endodônticos

“…Um cimento excessivamente solúvel pode permitir o desenvolvimento de lacunas entre a dentina radicular e o material, proporcionando vias de comunicação com os tecidos periapicais e a cavidade bucal (Al-haddad & Aziz, 2016), sendo esse fato desfavorável, na medida em que a desintegração do cimento possibilita o início de reações inflamatórias e de citotoxicidade (Lee et al, 2017). Ao longo do tempo, a solubilidade de um cimento pode atuar afetando negativamente o isolamento de microrganismos resistentes à desinfecção, comprometendo potencialmente o sucesso do tratamento endodôntico, como pontuam Saavedra et al (2022).…”

Stability and solubility test of endodontic materials

“…The environment in which the endodontic materials were tested, in this case artificial saliva, contains various ions, cations and organic substances that cause gradual deterioration of the material. As pointed out by Pilipenko et al, the degradation of endodontic materials is actually a chemical decomposition that leads to changes in the physical and mechanical characteristics of the material [9,15].…”

“…Sredina u kojoj su ispitivani endodontski materijali, u ovom slučaju veštačka pljuvačka, sadrži različite ajone, katjone i organske supstance koji izazivaju postepeno propadanje materijala. Kako ističu Pilipenko i saradnici, degradacija endodontskih materijala je zapravo hemijska razgradnja koja dovodi do promena fizičkih i mehaničkih karakteristika materijala [9,15].…”

Does the ultrasonic activation of calcium silicate-based sealers affect their physicochemical properties?

“…Ready-to-use bioceramic sealers have similar physicochemical characteristics, such as flow, setting time, radiopacity, and pH, but higher solubility according to the required standards 6 , 7 . BioRoot RCS shows a shorter setting time and flowability than Bio-C Sealer 8 . Both ready-to-use and powder/liquid bioceramic sealers are considered biocompatible and have bioactive potential 3 .…”