Antibacterial and antibiofilm activity over time of GuttaFlow Bioseal and AH Plus

Antibiofilm Efficacy of Calcium Silicate-Based Endodontic Sealers

BACKGROUND

Using endodontic sealers with long-term antimicrobial properties can increase the success of endodontic treatment. This study aimed to assess the antimicrobial activity over time of two calcium silicate (CS)-based sealers, AH Plus Bioceramic and BioRoot RCS, and to compare them with an epoxy resin-based sealer, AH Plus Jet, against mature polymicrobial biofilms grown on human radicular dentin.

METHODS

The antimicrobial activity of the sealers was tested using a direct contact test after 1 and 6 weeks of contact with the biofilms. Cell viability was determined by the adenosine triphosphate (ATP) method and flow cytometry (FC). The results of the ATP test were analyzed using an ANOVA with Welch's correction, followed by the Games-Howell test. The number of cells with damaged membranes obtained by FC in each period was compared by means of an ANOVA and Duncan's test. For the comparison between times, a Student's t-test was used.

RESULTS

Globally, after a week of contact, the epoxy resin-based sealer obtained the best results. However, at 6 weeks, the two CSs showed the highest antimicrobial efficacy, with a significant increase in this activity over time.

CONCLUSIONS

Calcium silicate-based sealers exert long-term antimicrobial activity against endodontic biofilms.

Biological properties versus solubility of endodontic sealers and cements

Endodontic sealers and cements used in root canal treatment have different compositions and properties. Common to all materials is that their primary goal is to fill gaps and voids, making a permanent seal of the root canal system. Furthermore, aspects such as antibacterial properties, cytotoxicity, setting time, solubility and biocompatibility are also crucial and ought to be considered. Over the years, a shift in the view on the importance of these aspects has ocurred. Whereas the antibacterial properties were considered important when the technical factors in endodontics were less developed, the sealing ability and biocompatibility have later been considered the most critical factors. The introduction of tricalcium silicate cements and sealers has led to a renewed interest in material properties, as these cements seem to have good sealing ability and at the same time combine favourable antimicrobial effects with excellent biocompatibility. This review discusses how the various properties of root canal sealers and cements may conflict with the primary aim of providing a permanent seal of the root canal system.

Evaluation of Antibacterial Effect of New Sealer "Neoseal" and Two Commercially Used Endodontic Sealers against Enterococcus faecalis: An In Vitro Study

AIM

To evaluate the antibacterial activity of three endodontic sealing materials, Neoseal, CeraSeal, and AH Plus against Enterococcus faecalis bacteria in vitro.

MATERIALS AND METHODS

The antibacterial activity of three endodontic sealing materials including two bioceramic sealers; NeoSEALER Flo (group I), CeraSeal (group II), and one epoxy resin sealer; AH Plus (group III) was investigated against E. faecalis bacteria American Type Cell Culture Collection (ATCC) 29212 (ATCC, Rockville, Maryland, USA). Using modified direct contact test (MDCT). The endodontic sealers were tested in contact with bacterial suspension when unset (20 minutes after mixing) and after setting, assessing the antibacterial activity of aged sealers after 1, 3, 7, and 14 days. Analyzing the collected data has been done with version 25.0 of the statistical package for the social sciences (SPSS) IBM software (SPSS, Chicago, Illinois, USA). Descriptive analyses were calculated using standard deviation (SD) and mean. Shapiro-Wilk test was done to detect the normality of the result values. Kruskal-Wallis test was then performed to test the level of significance between groups.

RESULTS

After 20 minutes - Group I showed higher bacterial count mean values (5,500 ± 500) and 0 values for groups II and III groups. After 1 day, the highest bacterial count mean values were in group III (54,333.3 ± 4,041.5) and 0 values for groups I and II. After 3 days - group III again recorded the highest bacterial count mean values (45,000 ± 5,000) and 0 values for I and II groups. After 7 days - Group III still recorded the highest bacterial count mean values (53,333.3 ± 1,527.5) and 0 values for groups I and II. After 14 days - Group III recorded the highest bacterial count mean values (56,000 ± 1,000) followed by group II (6,333.3 ± 577.4), and the least was group I (2,000 ± 500). Kruskal-Wallis test showed significant values between groups in all tested durations, p > 0.05.

CONCLUSION

The sealing material AH Plus showed a strong bactericidal effect at the beginning but lost its ability after 24 hours. CeraSeal showed strong bactericidal activity from the beginning till the end of the first week but showed bacterial count at 14 days. Neoseal took 24 hours to show bactericidal effect and similar to CeraSeal showed bacterial count at 14 days; CeraSeal recorded the best results within the study.

CLINICAL SIGNIFICANCE

Silicate-based (bioceramic) endodontic sealers can be the best available endodontic sealing material that is clinically beneficial in removing residual microbes which had survived irrigation protocols and chemomechanical preparation. How to cite this article: Basta DG, Reslan MR, Rayyan M, et al. Evaluation of Antibacterial Effect of New Sealer "Neoseal" and Two Commercially Used Endodontic Sealers against Enterococcus faecalis: An In Vitro Study. J Contemp Dent Pract 2023;24(11):871-876.

L-arginine-containing mesoporous silica nanoparticles embedded in dental adhesive (Arg@MSN@DAdh) for targeting cariogenic bacteria

Dental caries is the major biofilm-mediated oral disease in the world. The main treatment to restore caries lesions consists of the use of adhesive resin composites due to their good properties. However, the progressive degradation of the adhesive in the medium term makes possible the proliferation of cariogenic bacteria allowing secondary caries to emerge. In this study, a dental adhesive incorporating a drug delivery system based on L-arginine-containing mesoporous silica nanoparticles (MSNs) was used to release this essential amino acid as a source of basicity to neutralize the harmful acidic conditions that mediate the development of dental secondary caries. The in vitro and bacterial culture experiments proved that L-arginine was released in a sustained way from MSNs and diffused out from the dental adhesive, effectively contributing to the reduction of the bacterial strains Streptococcus mutans and Lactobacillus casei. Furthermore, the mechanical and bonding properties of the dental adhesive did not change significantly after the incorporation of L-arginine-containing MSNs. These results are yielding glimmers of promise for the cost-effective prevention of secondary caries.

Impacts of Resveratrol and Pyrogallol on Physicochemical, Mechanical and Biological Properties of Epoxy-Resin Sealers

This study aimed at evaluating the physicochemical and biological properties of experimental epoxy-resin sealers containing polyphenols such as resveratrol and pyrogallol. A conventional epoxy resin (OB) was modified by adding different concentrations of resveratrol (RS) or pyrogallol (PY) to its composition. Antibacterial and antioxidant activities, mechanical properties, along with wettability and morphological changes were investigated. The results were statistically analyzed using ANOVA and multiple comparison tests (α = 0.05). The incorporation of the tested polyphenols into the epoxy resin enhanced its mechanical properties. PY demonstrated much better antioxidant and antibacterial activities than RS, which were associated with a higher release of PY. In contrast, PY showed a higher cytotoxicity than OB and OB doped with RS. OB containing PY presented a rougher surface and higher water absorption than OB doped with RS. Both tested polyphenols caused no notable changes to the overall porosity of OB. Resveratrol and pyrogallol may not only influence the morphology and mechanical properties of epoxy-resin sealers, but could also enhance antioxidant activity and antibacterial effects against Enterococcus faecalis. Most epoxy-resin sealers currently available in the market can be considered as “passive” materials. Thus, doping their composition with specific polyphenols may be a suitable strategy to confer some antibacterial properties, antioxidant potential, along with improvement of some mechanical properties.

In vitro evaluation of the antibacterial effect of four root canal sealers on dental biofilms

OBJECTIVES

To dynamically evaluate the effect of four root canal sealers on the killing of biofilms within dentinal tubules.

MATERIALS AND METHODS

Dentin blocks were prepared for infection of the dentinal tubules. Enterococcus faecalis VP3-181 and multi-species bacteria from two donors were cultured. After 3 days of incubation, the infected dentin specimens were rinsed with sterile water for 1 min and subjected to treatment. Additionally, multi-species bacteria from donor 1 were incubated for 3 weeks to allow biofilm maturation and then the specimens were subjected to treatment. Gutta-percha-treated dentin specimens comprised the control group. A root canal sealer (bioceramic sealers: EndoSequence BC Sealer, ProRoot Endo Sealer, or GuttaFlow Bioseal; and a traditional silicone-based sealer: Guttaflow 2) was spread onto the canal walls of the dentin. The specimens were examined with confocal laser scanning microscopy at 7, 30, or 60 days.

RESULTS

In the 3-day-old biofilm group, the proportion of killed bacteria decreased significantly from the first 7 days of treatment to 60 days of treatment for all sealers (p < 0.05). In the 3-week-old biofilm group, 60 days of exposure to bioceramic sealers resulted in more significant dead bacteria than 7-day exposures of the biofilms (p < 0.05). Bioceramic sealers were more effective in killing bacteria than the GuttaFlow 2 sealer (p < 0.05).

CONCLUSIONS

Calcium silicate-based sealers showed good antimicrobial effects against biofilms within dentinal tubules, especially in the first week in young biofilms. There is no substantive antibacterial activity observed for the examined root canal sealers against young dentinal tubule biofilms.

CLINICAL RELEVANCE

The bioceramic root canal sealers examined demonstrate minimal additional antibacterial effects after long-term exposure to young biofilms.

A comprehensive in vitro comparison of the biological and physicochemical properties of bioactive root canal sealers

OBJECTIVES

To evaluate the biological and physicochemical features of bioactive root canal sealers.

MATERIALS AND METHODS

Human periodontal ligament fibroblasts (hPDLF) and human osteoblasts (hOB) were exposed to eluates of three bioactive root canal sealers, GuttaFlow® bioseal (GF), BioRoot™ RCS (BR), and TotalFill® BC Sealer (TF), and the epoxy resin-based sealer AH plus® (AH). Cytotoxicity and cellular inflammatory response were evaluated. The osteogenic potential was examined using human mesenchymal stem cells (hMSC). Film thickness, flowability, and pH were assessed. Root canal treatment was performed on human extracted teeth to evaluate the sealers' tightness towards bacterial penetration. The antibacterial activity against common pathogens in primary root canal infections was tested.

RESULTS

AH was severely cytotoxic to hPDLF and hOB (p < 0.001). The bioactive sealers were generally less cytotoxic. IL-6 levels in hPDLF were elevated in the presence of AH (p < 0.05). AH and GF suppressed IL-6 production in hOB (p < 0.05). AH and BR stimulated the PGE₂ production in hPDLF and hOB (p < 0.05). BR was the only sealer that led to calcium deposits in hMSC (p < 0.05). TF and AH showed the lowest film thickness and the highest flowability. Bacterial tightness was best in teeth filled with AH and BR. All sealers showed similar antimicrobial activity, but the overall antimicrobial efficacy was moderate as the bacteria were reduced by just one log scale (p < 0.05).

CONCLUSIONS

This study revealed favorable in vitro results regarding the biocompatibility of the bioactive root canal sealers.

CLINICAL RELEVANCE

Bioactive root canal sealers may be a useful alternative to epoxy resin-based sealers.

Comparison of Obturation Quality between Calcium Silicate-Based Sealers and Resin-Based Sealers for Endodontic Re-treatment

BACKGROUND

The objective of this micro-computed tomography (micro-CT)-based study was to compare the filling quality of endodontic treatment and endodontic Re-treatment between two sealers with matched obturation techniques: calcium silicate-based sealer (Endoseal TCS) with a single-cone technique (SCT) and resin-based sealer (AH Plus) with a continuous wave technique (CWT).

METHODS

Forty maxillary premolars were selected and assigned into four groups, according to the obturation methods of the first endodontic treatment and Re-treatment (n = 10). The AP/AP group was first treated with AH Plus/CWT, then re-treated with AH Plus/CWT. The AP/ET group was first treated with AH Plus/CWT, then re-treated with Endoseal TCS/SCT. The ET/AP group was first treated with Endoseal TCS/SCT, then re-treated with AH Plus/CWT, and the ET/ET group was first treated with Endoseal TCS/SCT, then re-treated with Endoseal TCS/SCT. The specimens were scanned using micro-CT at three time points: after the first endodontic treatment, after gutta-percha (GP) cone removal, and after Re-treatment. The void volume of root canal obturation and the volume of the remaining filling materials were calculated. Data were analyzed using Student's t-tests and ANOVA.

RESULTS

The Endoseal TCS groups (ET/AP and ET/ET) showed a lower percentage of voids than the AH plus groups (AP/AP and AP/ET) on the whole canal and the apical third, after first obturation (p < 0.05). The AH plus group showed significantly fewer remnants than the Endoseal TCS group after GP removal (p < 0.05). Re-treated canals and initially treated canals had similar void volumes (p > 0.05). There was no significant difference in void volume after Re-treatment, regardless of whether the same or different sealers were used for the first treatment and Re-treatment (p < 0.05).

CONCLUSIONS

Endoseal TCS sealer and AH Plus sealer had a similar Re-treatment efficacy, regardless of which sealer was used in the previous treatment.

Antimicrobial effects of a new brushing solution concept on a multispecies in vitro biofilm model growing on titanium surfaces

OBJECTIVES

To evaluate the antibiofilm and antibacterial effects of a new brushing solution concept, in a validated peri-implant biofilm model.

MATERIALS AND METHODS

A multispecies in vitro biofilm model, including Streptococcus oralis, Actinomyces naeslundii, Veillonella parvula, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum, was used. To evaluate the antibiofilm capacity, titanium discs (Ti-SLA) were immersed in 1 ml of the tested solution (one tablet dissolved in warm water) for 2 min, prior and every 24 h during a 3-day biofilm development. Negative (water) and positive (0.12% chlorhexidine/0.05% cetylpyridinium chloride mouth rinse) controls treated discs were run in parallel. To evaluate the antibacterial effects, planktonic cells and 72-h biofilms on sterile Ti-SLA discs were exposed (2 min) to the mentioned treatments. Biofilm structure was analysed by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Bacterial load was measured by quantitative polymerase chain reaction and by culture in planktonic cells.

RESULTS

The tested product showed antibiofilm effects, impacting on the 48-h and 72-h biofilm thickness and significantly reducing viability of all bacterial species, except A. actinomycetemcomitans. Antibacterial effects were observed against the six bacterial species in planktonic state and in 72-h biofilms, especially for F. nucleatum and A. actinomycetemcomitans.

CONCLUSION

The tested brushing solution demonstrated antibacterial and antibiofilm properties, mainly against the peri-implant pathogens included in the validated in vitro biofilm model used.

Antibiofilm potential over time of a tricalcium silicate material and its association with sodium diclofenac

OBJECTIVES

The objectives of this study are to investigate, over time, the antimicrobial activity against polymicrobial biofilms and ability to inhibit biofilm formation, of Biodentine (BD) alone and with 5% and 10% sodium diclofenac (DC).

MATERIAL AND METHODS

The antimicrobial activity of BD alone and modified with 5% and 10% DC against polymicrobial biofilm growth in dentin was determined by a modified direct contact test. The study groups were (1) BD; (2) BD + 5% DC; and (3) BD + 10% DC. The viability of microorganisms after 1 and 4 weeks was quantified by means of an ATP assay and flow cytometry. The antibiofilm efficacy of the materials, preventing polymicrobial biofilm formation over time, was assessed by confocal laser scanning microscopy (CLSM).

RESULTS

The results obtained with both the ATP test and flow cytometry showed that BD alone and with 5% and 10% DC exerted antibiofilm activity with respect to the control, in the two evaluated times (p < 0.001). Comparison between groups showed a tendency of increased antimicrobial effect, both over time and depending on the DC concentration. These results coincide with those obtained in CLSM analysis, where efficacy increased with time and DC concentration.

CONCLUSIONS AND CLINICAL RELEVANCE

Biodentine, over time, showed antimicrobial and antibiofilm efficacy on polymicrobial biofilms. The addition of 5% and 10% DC to BD enhanced this effect, in a concentration- and time-dependent manner.

Antimicrobial Activity of Nano-Magnesium Hydroxide Against Oral Bacteria and Application in Root Canal Sealer

BACKGROUND The goal of the present work was to assess the antibacterial activity of nano-magnesium hydroxide (NMH) against Streptococcus mutans (S. mutans) and to explore the antimicrobial function of AH Plus™ sealer incorporating NMH. MATERIAL AND METHODS The antimicrobial behavior of NMH against S. mutans was evaluated with bactericidal tests. A modified direct contact test was used to assess the antimicrobial activity of unset AH Plus containing NMH after 5 minutes, 20 minutes, and 60 minutes of contact with bacteria. The antimicrobial effects and the amount of surface-adhering bacteria of the solidified materials were explored by SEM and confocal laser scanning microscopy, respectively. RESULTS NMH powder presented excellent antimicrobial activity against S. mutans. Mg²⁺ and OH⁻ were not the main factors resulting in bacterial death. Approximately 93.1% and 98% of the S. mutans were killed in the AH Plus+7% NMH group after incubation for 5 minutes and 20 minutes, respectively. AH Plus with 5% or 7% NMH were more potent against S. mutans compared with AH Plus alone (P<0.05). Moreover, the antibacterial function of AH Plus was lost after setting. NMH enabled the solidified AH Plus to still have antibacterial properties on the seventh day. CONCLUSIONS NMH can be used to modify AH Plus sealer to eradicate residual bacteria and prevent reinfection.