Antimicrobial Activity of Five Calcium Silicate Based Root Canal Sealers against a Multispecies Engineered Biofilm: An In Vitro Study.

AIM: The present study's objective was to compare the impact of CerasealR, total fill BC SealerR, Bio-C SealerR, AH Plus BioceramicR, and K-BiocerR on the elimination of a multispecies' endodontic biofilm at 3, 7 and 14 days. MATERIALS AND METHODS: A total of 20 freshly extracted, caries-free premolars were prepared for the study to create dentinal disks. For the multispecies biofilm formation, Enterococcus faecalis, Proteus mirabilis, Pseudomonas aeruginosa, and Candida albicans were cultured and used to inoculate hydroxyapatite discs. After incubation, the biofilms were placed on blotting papers in petri dishes with an orthodontic bend. Different root canal sealers, including CeraSeal, total Fill BC Sealer, Bio-C Sealer, AH Plus Bioceramic, K-Biocer, and Sealite, were injected into the bend, facilitating contact with the biofilms. The samples were divided into seven groups, including a negative control. At specific intervals, 3, 7, and 14 days, 3 biofilm samples from each group were collected, diluted, and plated on Agar media for colony counting and analysis. RESULTS: In all tested groups, the total bacterial count significantly decreased between day 3 and 14 (p < 0.05) with no statistically significant differences among the different sealers' groups at all-time points for the total bacterial count, E. faecalis count, and P. mirabilis count. However, Sealite demonstrated the most consistent effectiveness in reducing bacterial counts across multiple categories. The sealite group was capable of decreasing the C. albicans count significantly between day 3 and day 14 (p < 0.05) in comparison with the bioceramic groups. CONCLUSION: All sealers had antibacterial activity against the multispecies biofilm between day 3 and day 14. The ascending order of sealers in terms of their effectiveness in killing bacteria, based on the provided results, is as follows: Sealite, Bio-C Sealer, AH Plus, CeraSeal, TotalFill, and K-Biocer. However, there were no statistically significant differences in the bacterial counts among the different sealer groups at any time point. CLINICAL SIGNIFICANCE: The role of sealers in combating biofilm-associated infections highlights their potential clinical utility in preserving root canal health. Understanding the antimicrobial properties of these sealers is vital for informed decision-making in selecting the most effective materials for improved treatment outcomes and long-term success in endodontic procedures.

Impact of Final Irrigation Protocol on the Push-Out Bond Strength of Two Types of Endodontic Sealers.

Aim: The aim of this study was to assess the impact of the final irrigation protocol on the push-out bond strength of calcium silicate-based sealers when compared to an epoxy resin-based sealer. Materials and Methods: Eighty-four single-rooted mandibular human premolars were shaped using the R25® instrument (Reciproc, VDW, Munich, Germany) and then divided into three subgroups of 28 roots each depending on the final irrigation protocol: EDTA (ethylene diamine tetra acetic acid) and NaOCl activation, Dual Rinse® HEDP (1-hydroxyethane 1,1-diphosphonate) activation or sodium hypochlorite (NaOCl) activation. Then, each subgroup was divided into two groups (14 each) according to the sealer used (AH Plus Jet® or Total Fill BC Sealer®) for single-cone obturation. Dislodgement resistance using a universal testing machine, samples' push-out bond strength and failure mode under magnification were determined. Results: EDTA/Total Fill BC Sealer® showed significantly greater values of push-out bond strength compared with HEDP/Total Fill BC Sealer® and NaOCl/AH Plus Jet®, with no statistical difference with EDTA/AH Plus Jet®, HEDP/AH Plus Jet® and NaOCl/Total Fill BC Sealer®, whereas HEDP/Total Fill BC Sealer® showed significantly lower values of push-out bond strength. The apical third demonstrated higher means of push-out bond strength compared with middle and apical thirds. The most common failure mode was cohesive but showed no statistical difference compared to other types. Conclusions: Irrigation solution and final irrigation protocol affect the adhesion of calcium silicate-based sealers.

In vitro evaluation of enterococcus faecalis growth in different conditions on dentinal substrate.

The aim of this study was to find the best growth conditions of Enterococcus faecalis on a dentinal substrate in order to be used for the development of a complex multispecies endodontic biofilm. Fifty two single rooted extracted human teeth and fifty two dentinal disks were mechanically prepared, sterilized, inoculated with Enterococcus faecalis and divided randomly into 8 groups where the substrate, the inoculation technique, the medium type, and the pre-treatment with collagen type I was varied. Bacterial count was evaluated and colonies were counted and confirmed by colony morphology observation on blood agar and Gram staining at 3,7, 14, 21, and 28 days. On day 14 of the culture, the bacterial count showed the highest values in all groups. Root canals and Type 1 collagen pre-treatment and glucose proved to have significant positive effects on the bacterial count compared to dentinal disks and BHI media only. The increase in bacterial count found with the direct inoculation technique was not significantly different from that of the indirect technique.

In vitro evaluation of three engineered multispecies endodontic biofilms on a dentinal disk substrate.

The aim of this study was the development of a complex multispecies endodontic biofilm using Candida albicans, Proteus mirabilis and Pseudomonas aeruginosa on a biofilm of Enterococcus faecalis in a dentinal substrate design. The endodontic pathology is a biofilm-mediated infection, and the aim of root canal therapy is to reduce, as much as possible, the bacterial population. Thus, it is important to develop a laboratory endodontic biofilm to test the effect of new irrigation and obturation techniques on reduction of bacterial count. The culture of Enterococcus faecalis from ATCC 29212 began with aerobic cultivation on blood agar, followed by transfer to Brain Heart Infusion (BHI) broth with 5% sucrose. Incubation occurred in a shaker at 37 °C for 24 h, followed by an additional 24-h static phase. After 10 d, Proteus mirabilis, Pseudomonas aeruginosa, and Candida albicans were introduced sequentially in three distinct groups. Group 1: the order of addition was Candida albicans, Proteus mirabilis, and Pseudomonas aeruginosa; Group 2: the order was Pseudomonas aeruginosa, Candida albicans, and Proteus mirabilis; and Group 3: Proteus mirabilis, Pseudomonas aeruginosa, and Candida albicans. After 16 days, the biofilm was carefully extracted, transferred to sterile BHI, and dissected using a sterile needle technique. Subsequently, an optical density test, bacterial counts, and colony enumeration were performed on various agar plates. Group 2 in which Pseudomonas aeruginosa was added directly after Enterococcus faecalis followed by Candida albicans and Proteus mirabilis showed significantly greater total bacterial count than the other two groups.

Canal Transportation and Centring Ability of Reciproc and Reciproc Blue With or Without Use of Glide Path Instruments: A CBCT Study.

Objective: The objective of this ex vivo study was to evaluate canal transportation and centring ability of Reciproc and Reciproc blue systems in curved root canals with or without prior use of PathFile rotary system (PF) using Cone Beam Computed Tomography (CBCT). Methods: One hundred and twenty curved root canals from maxillary and mandibular premolars were selected. Canals were divided randomly into 4 groups (n=30): Reciproc 25 (R25), (PF+R25), Reciproc Blue 25 (RB25), (PF+RB 25). Specimens were scanned before and after root canal preparation. Using CBCT, root canal transportation and centring ability was assessed by measuring the shortest distance from the edge of uninstrumented canal to the periphery of the root (mesial and distal) before and after preparation. Data were analysed using a one-way analysis of variance and Tukey test. The p value was set at 0.05. Results: Less transportation and better centring ability occurred when PF was used before R25 or RB25 (P<0.0001). There was no significant difference between R25 and RB25 groups. Conclusion: Using PF before R25 and RB25 resulted in less root canal transportation and better centring ability. The specific thermo-mechanical treatment of RB25 did not provide better results when compared to R25.

Impact of Different Irrigant Agitation Methods on Bacterial Elimination from Infected Root Canals.

Activation techniques are essential for root canal disinfection but may result in incomplete removal of bacteria. The aim of our study was to assess the antibacterial action of sonically, ultrasonically and laser-activated irrigation and 5.25% sodium hypochlorite (NaOCl) on Enterococcus faecalis in an infected tooth. Forty-four extracted mandibular premolars were mechanically prepared, sterilized, and inoculated with E. faecalis for 1 week. Bacterial counts after inoculation were evaluated in 4 randomly chosen teeth, remaining root canals were divided into 4 groups. Group A: laser-activated irrigation by photon-induced photoacoustic streaming, Group B: the sonic irrigation by EDDY, Group C: ultrasonic irrigation by EndoUltra, and Group D: 5.25% NaOCl. Colony forming unit (CFU) counts were measured and Kolmogorov-Smirnov, Wilcoxon, Kruskal-Wallis and Mann-Whitney tests were used to determine differences. The mean of CFU was found to significantly decrease in group D, 2110 ± 1015.93 (p < 0.001). Changes in measurement levels followed the same trend over time in groups A 27.40 ± 30.15, B 81.3 ± 85.68 and C 44.40 ± 67.12 (p = 0.141). The average CFU after irrigation in all groups was significantly greater than 0. Within the limitations of this study, all activation techniques were superior to NaOCl 5.25% in reducing E. faecalis from the infected tooth model.