Comparison of antibacterial activity of two dentin bonding systems using agar well technique and tooth cavity model

Lactiplantibacillus plantarum from Unexplored Tunisian Ecological Niches: Antimicrobial Potential, Probiotic and Food Applications

The continued exploration of the diversity of lactic acid bacteria in little-studied ecological niches represents a fundamental activity to understand the diffusion and biotechnological significance of this heterogeneous class of prokaryotes. In this study, Lactiplantibacillus plantarum (Lpb. plantarum) strains were isolated from Tunisian vegetable sources, including fermented olive and fermented pepper, and from dead locust intestines, which were subsequently evaluated for their antimicrobial activity against foodborne pathogenic bacteria, including Escherichia coli O157:H7 CECT 4267 and Listeria monocytogenes CECT 4031, as well as against some fungi, including Penicillium expansum, Aspergilus niger, and Botrytis cinerea. In addition, their resistance to oro-gastro-intestinal transit, aggregation capabilities, biofilm production capacity, adhesion to human enterocyte-like cells, and cytotoxicity to colorectal adenocarcinoma cell line were determined. Further, adhesion to tomatoes and the biocontrol potential of this model food matrix were analyzed. It was found that all the strains were able to inhibit the indicator growth, mostly through organic acid production. Furthermore, these strains showed promising probiotic traits, including in vitro tolerance to oro-gastrointestinal conditions, and adhesion to abiotic surfaces and Caco-2 cells. Moreover, all tested Lpb. plantarum strains were able to adhere to tomatoes with similar rates (4.0-6.0 LogCFU/g tomato). The co-culture of LAB strains with pathogens on tomatoes showed that Lpb. plantarum could be a good candidate to control pathogen growth. Nonetheless, further studies are needed to guarantee their use as probiotic strains for biocontrol on food matrices.

Evaluation of the Antibacterial Effects of Four Different Adhesives Against Three Bacterial Species in Two Time Periods: An In Vitro Comparative Study

Aim:

The study aimed at evaluating the antibacterial activities of four adhesive systems against three bacterial species in two time periods.

Material and Method:

Four different antibacterial adhesive materials, a nonantibacterial adhesive (Clearfil SE Bond), and a vancomycin-impregnated antibiogram disc were used in the study. The antibacterial activities of Gluma 2 Bond, Clearfil SE Protect Bond (CPB) Primer, FL Bond II (FLB), and Peak Universal Bond (PUB) on Enterococcus faecalis, Streptococcus mutans, and Lactobacillus acidophilus were evaluated by the disc diffusion method. Antibiogram discs onto which the adhesive agent was dripped were placed on agar plates at intervals. Inhibition zone diameters around the discs, which were incubated, were measured. Statistical analysis was done with the one-way analysis of variance.

Results:

As a result of our study, it was concluded that the CPB Primer was the agent with the highest antibacterial activity, including the control group. One of the remarkable findings in our study was that CPB Primer showed the most significant effect against Streptococcus mutans among microorganisms. Although not statistically significant, the antibacterial effect of adhesive agents at the end of the 48th h was found to be higher than at the end of the 24th h ( P > .05).

Conclusion:

The strong antibacterial activity of the CPB Primer on all three bacteria suggests that it is a preferable adhesive agent in deep dentinal caries as well as in initial caries lesions.

Evaluation of human pulp tissue response following direct pulp capping with a self-etching adhesive system containing MDPB

This study evaluated the human pulp tissue response following direct pulp capping with Clearfil Protect Bond (CPB) self-etching adhesive containing an antibacterial monomer MDPB. The pulps of third molar teeth were exposed by the removal of carious tissue. In an experimental group, CPB was applied to the exposed pulp and dentin. In the control groups, Clearfil SE Bond (CSE) or calcium hydroxide-based cement (CH) was applied to the exposed pulp surfaces. All teeth were filled with resin composite, extracted after 90 days, and the pulp responses were histologically analyzed. No severe inflammation or soft tissue disorganization was observed in CPB and CH groups. CSE group exhibited a disorganized odontoblastic layer and severe inflammatory infiltration. No hard tissue formation was observed in CSE group, and CH formed more of a hard tissue formation than CPB. CPB induced an acceptable healing response when directly applied to exposed pulps with bacterial contamination.

Bibliometric Analysis of Literature Published on Antibacterial Dental Adhesive from 1996-2020

This study aimed to investigate the current state of research on antibacterial dental adhesives. The interest in this field can be drawn from an increasing number of scholarly works in this area. However, there is still a lack of quantitative measurement of this topic. The main aim of this study was to consolidate the research published on the antibacterial adhesive from 1996 to 2020 in Web of Science indexed journals. The bibliometric method, a quantitative study of investigating publishing trends and patterns, was used for this study. The result has shown that a gradual increase in research was found, whereby a substantial increase was observed from 2013. A total of 248 documents were published in 84 journals with total citations of 5107. The highly cited articles were published mainly in Q1 category journals. Most of the published articles were from the USA, China, and other developed countries; however, some developing countries contributed as well. The authorship pattern showed an interdisciplinary and collaborative approach among researchers. The thematic evaluation of keywords along with a three-factor analysis showed that 'antibacterial adhesives' and 'quaternary ammonium' have been used commonly. This bibliometric analysis can provide direction not only to researchers but also to funding organizations and policymakers.

Flow Cytometry Analysis of Antibacterial Effects of Universal Dentin Bonding Agents on Streptococcus mutans

There is no consensus on the antibacterial activity of dentin bonding systems (DBS). Many study models have been used to evaluate the antimicrobial activity of dental materials. In this study, a novel detection method, flow cytometry, was introduced. It allows for evaluation of the antibacterial activity of DBS, based on assessment of the disruption of the bacterial physical membrane induced by DBS. The aim of the study was to evaluate the antibacterial properties of selected dentin bonding systems against Streptococcus mutans. The highest antibacterial activity against S. mutans was observed for Adhese Universal (99.68% dead cells) and was comparable to that of Prime&Bond Universal, OptiBond Universal, or Clearfil Universal Bond Quick (p > 0.05). The lowest activity of all tested systems was displayed by the multi-mode adhesive, Universal Bond (12.68% dead bacteria cells), followed by the self-etch adhesive, OptiBond FL (15.58% dead bacteria cells). The present study showed that in the case of two-component DBS, the primer exhibited higher antimicrobial activity than the adhesive (or bond) itself.

In vitro antibacterial activity of self-etch bio-active dental adhesives after artificial aging

Purpose:

The aims to evaluate the antibacterial effect of different bioactive component containing dental adhesives before and after artificial aging.

Materials and methods:

Two bio-active adhesives; Clearfil Protect Bond and FL Bond II, two non-bioactive adhesives, Clearfil SE Bond and Clearfil S3 Bond were used for this study. Antibacterial activities of the fresh and aged samples against Streptococcus mutans were investigated with Direct Contact Test. Data were analyzed with Kruskal Wallis and Mann Whitney U multiple comparison tests.

Results:

For fresh samples FL Bond II and Clearfil Protect Bond exhibit similar antibacterial effect but Clearfil Protect Bond showed significantly higher antibacterial effect after aging the samples (p<0.05).

Conclusion:

The incorporation of bio-active antibacterial components into adhesive systems may be considered as a fundamental component in inhibiting residual Streptococcus mutans when considering the antibacterial effect of fresh samples of bio-active adhesives.

Antibacterial Activity of Commercial Dentine Bonding Systems against E. faecalis-Flow Cytometry Study

Literature presents inconsistent results on the antibacterial activity of dentine bonding systems (DBS). Antibacterial activity of adhesive systems depends on several factors, including composition and acidity. Flow cytometry is a novel detection method to measure multiple characteristics of a single cell: total cell number, structural (size, shape), and functional parameters (viability, cell cycle). The LIVE/DEAD^® BacLight™ bacterial viability assay was used to evaluate an antibacterial activity of DBS by assessing physical membrane disruption of bacteria mediated by DBS. Ten commercial DBSs: four total-etching (TE), four self-etching (SE) and two selective enamel etching (SEE) were tested. Both total-etching DBS ExciTE F and OptiBond Solo Plus showed comparatively low antibacterial activity against E. faecalis. The lowest activity of all tested TE systems showed Te-Econom Bond. Among SE DBS, G-ænial Bond (92.24% dead cells) followed by Clearfil S3 Bond Plus (88.02%) and Panavia F 2.0 ED Primer II (86.67%) showed the highest antibacterial activity against E. faecalis, which was comparable to isopropranol (positive control). In the present study, self-etching DBS exhibited higher antimicrobial activity than tested total-etching adhesives against E. faecalis.

In vitro evaluation of shear bond strength of nanocomposites to dentin

AIMS

To compare the shear bond strength of nanocomposites to dentin using three different types of adhesive systems; and to test few specimens under Scanning Electron Microscope (SEM) for analysing whether the bond failure is adhesive or cohesive.

MATERIALS AND METHODS

Sixty human premolar teeth were selected and were randomly grouped, with 20 specimens in each group: group 1 - fluoride releasing dentin bonding agent; group 2 - antibacterial containing dentin bonding agent; and group 3 - one step conventional self etch adhesive. Each group was treated with its respective bonding agents, composite resin build up was done, and shear bond strengths were tested using Instron Universal testing machine. Few of the specimens were tested under SEM.

RESULTS

The results were statistically analysed using One-way ANOVA and paired t-test. It was observed that group 3 has the highest shear bond strength followed by group 2, and then group 1. Adhesive failures and mixed failures were most frequent types of failures as seen under SEM.

CONCLUSION

Addition of antimicrobial agent decreases the bond strength of dentin bonding agent and addition of fluoride further decreases the bond strength. From SEM results it can be concluded that the zone of failure could not be defined and also that the failure mode was independent of the dentin bonding agent used.

Development of an antibacterial root canal filling system containing MDPB

An antibacterial monomer 12-methacryloyloxydodecylpyridinum bromide (MDPB)-containing experimental, chemically cured primer was prepared to develop a new resin-based root canal filling system. This study investigated the antibacterial effects of the MDPB-containing primer (experimental primer [EP]) against Enterococcus faecalis and assessed the in vitro bonding and sealing abilities of the filling system, consisting of EP and a Bis-GMA-based sealer resin. Antibacterial effects of EP were evaluated by contact with planktonic or adherent bacteria for 30 or 60 sec, and the viable bacterial number was counted. The antibacterial effects against E. faecalis in dentinal tubules were also assessed, according to a root canal infection model. Bonding and sealing abilities of the experimental filling system were examined by microtensile bond strength tests and leakage tests based on fluid filtration methods. Significantly greater reduction in viable bacteria in planktonic and adherent form was obtained by short-period contact with EP compared with the control primer (without MDPB) or with the proprietary (Epiphany) primer (p < .05). Significantly greater bactericidal effects of the EP inside the dentinal tubule of root, as opposed to the control primer or Epiphany primer, were confirmed according to a root canal infection model (p < .05), and 100% killing of E. faecalis could be obtained by the application of EP after irrigation with a 5% sodium hypochlorite solution. The experimental endodontic filling system demonstrated significantly greater bond strength to root dentin than Epiphany sealer system (Epiphany primer and Epiphany Root Canal Sealant; p < .05), showing formation of resin tags and a hybridized layer. Leakage tests clarified that the experimental system provided excellent sealing. This study confirmed that the MDPB-containing experimental antibacterial primer has the ability to effectively disinfect the root canal. Additionally, the experimental root canal filling system employing this primer and the Bis-GMA-based sealer resin is useful for achieving good sealing, suggesting its possible benefit for successful endodontic treatments.

Comparative evaluation of the antibacterial effects of four dentine bonding systems: An in vitro study

Aim:

The aim of this in vitro study was to evaluate and the compare antibacterial efficacy of four dentin bonding system against Streptococcus mutans, Streptococcus salivarius and Lactobacillus acidophilus over a period of three months using agar disk diffusion test.

Methodology:

All the three standard bacterial strains were inoculated into BHI broth and incubated at 37°C for 48 hours. A 100 μl of broth suspension containing aliquots of S. mutans, S. salivarius and L. acidophilus were spread onto M-H agar medium using sterile cotton swabs. The experimental groups were as follows: GROUP A: Test conducted for evaluation of antimicrobial efficacy against S. mutans MTCC 497, GROUP B: Test conducted for evaluation of antimicrobial efficacy against S. salivarius MTCC 1938, and GROUP C: Test conducted for evaluation of antimicrobial efficacy against L. acidophilus MTCC 447. For sample preparation, 20 μl bonding agent was dropped with micropipettes on paper disks, and blown dry for 10 seconds. Then it was light-cured at 2 mm for 20 sec using a QTH visible light curing unit. For first reading, the sample disks were placed over the freshly inoculated agar plates and then incubated at 37°C for 48 hours. The rest of the paper disks were stored in dark, submerged in distilled water at 37°C. They were placed on freshly inoculated spread plates after specific time intervals- 1 day, 1 week, 2 weeks, 1 month and 3 months after ageing in PBS. After incubation, the diameters of zones of inhibition around the plates were measured. The experiment was performed twice in triplicate. The data was then statistically analysed using Two way ANOVA test and post hoc.

Results:

Results showed that Xeno III had the maximum antibacterial efficacy over a period of three months, followed by XP bond. This antibacterial activity was maximum against Streptococcus mutans, followed by Lactobacillus acidophilus and least against Streptococcus salivarius. Adper Easy One and G bond had minimal effect against the test bacteria during the test period.

Conclusion:

The antibacterial effect decreased over a period of three months for all the dentin bonding systems.

Comparing the antibacterial activity of gaseous ozone and chlorhexidine solution on a tooth cavity model

OBJECTIVE

To evaluate the antibacterial activity of gaseous ozone and chlorhexidine solution on a tooth cavity model.

STUDY DESIGN

Twenty-one human molars were divided into 3 groups. Cavities were then cut into the teeth (4 per tooth, 28 cavities per group). After sterilization, the teeth were left in broth cultures of 106 colony-forming units (CFU) ml-1 of Streptococcus mutans (S. mutans) at 36°C for 48 h. The appropriate treatment followed (group A, control; group B, 2% chlorhexidine solution; and group C, 80s of treatment with ozone, and the cavities were then filled with composite resin. After 72h, the restorations were removed, dentin chips were collected with an excavator, and the total number of microorganisms was determined.

RESULTS

Both of the treatments significantly reduced the number of S. mutans present compared with the control group and there was a significant difference between the all groups in terms of the amount of the microorganisms grown (p < 0.05). Group B was beter than group C; and group C was better than group A. Moreover, it was found that the amount of the growth in the group of chlorhexidine was significantly less than that of the ozone group (p < 0.05).

CONCLUSION

Chlorhexidine solution was the antibacterial treatment most efficacious on S. mutans; however, ozone application could be an anlternative cavity disinfection method because of ozone's cavity disinfection activity. Key words:Antibacterial activity, chlorhexidine, ozone, streptococcus mutans, tooth cavity.

Bactericidal effects of 2.94 µm and 1.67 µm laser

The bactericidal effects of lasers with wavelengths of 1.67 and 2.94 µm on cariogenic Streptococcus mutans were investigated. Temperature during irradiation was also measured to determine the mechanism underlying the bactericidal effects of the lasers. An aliquot of 2 µl cell suspension of S. mutans JC-2 strain was placed on anhydrous quartz or dentin plate, covering an area of approximately 5.0 mm in diameter to a depth of approximately 0.1 mm. Cell suspension was then irradiated at a power of 0.8 W (3.1 J/cm²) at a rate of 40 pps for 30 sec. After irradiation, the plate was put into a bottle containing PBS and vigorously voltated. Solution was serially diluted and inoculated on MS agar. After incubation anaerobically for 72 hr, colony forming units on the agar were counted. The experimental group, the number of bacteria decreased significantly compared to the control group under all conditions. No significant differences were observed in effect of wavelength or plate on bactericidal activity. In conclusion, laser irradiation at a wavelength of 1.67 µm for 30 sec showed a bactericidal effect on S. mutans, suggesting that this wavelength is more useful than 2.94 µm due to greater tissue penetration.

Bio-active restorative materials with antibacterial effects: new dimension of innovation in restorative dentistry

Restorative materials in the new era should be "bio-active", and antibacterial effects are highlighted as one of the important properties. In order to achieve resin-based restoratives with antibacterial effects, an antibacterial monomer MDPB has been developed. The primer incorporating MDPB demonstrated cavity-disinfecting effects, and the world's first antibacterial adhesive system employing the MDPB-containing primer was successfully commercialized. MDPB is potentially applicable to various restoratives since immobilization of the antibacterial component by polymerization of MDPB enables no deterioration in mechanical properties of cured resins and exhibition of inhibitory effects against bacterial growth on their surfaces. For glass-ionomer cements used for atraumatic restorative treatment, the approach to provide antibacterial activity has been attempted by addition of chlorhexidine. Incorporation of 1% chlorhexidine diacetate was found to be optimal to give appropriate antibacterial and physical properties, being effective to reduce the bacteria in affected and infected dentin in vivo.

Evaluation of the shear bond strength of 3 curing bracket bonding systems combined with an antibacterial adhesive

INTRODUCTION

The purpose of this in-vitro study was to investigate the shear/peel bond strength of metal brackets bonded to human enamel with differently cured bonded systems combined with an antibacterial adhesive component.

METHODS

One hundred twenty extracted molars were divided into 3 groups. Stainless steel brackets were bonded with 1 of 3 systems: group 1, no-mix bonding adhesive (Unite, 3M Unitek, Monrovia, Calif) (n = 40); group 2, 2-paste chemically cured bonding resin (Concise, 3M Unitek) (n = 40); and group 3, light-cured adhesive (Transbond XT, 3M Unitek) (n = 40). Each bonding group was separated into experimental (n = 20) and control groups (n = 20). In the 3 experimental groups, an antibacterial self-etch adhesive (Clearfil Protect Bond, Kurary, Osaka, Japan) was also applied to the enamel. Specimens in the control groups were bonded only with their relevant bonding systems according to the manufacturers' instructions. All specimens were stored in distilled water for 24 hours and thermocycled before testing. Debonded specimens were scored with the adhesive remnant index.

RESULTS

The mean bond strengths (in megapascals) were 9.8 (control, 15.7) in group 1, 12.0 (control, 18.5) in group 2, and 11.6 (control, 12.4) in group 3. Statistical analysis with t tests showed no difference between group 3 and its control (P = .178), whereas groups 1 and 2 were statistically different from their controls (P = .000).

CONCLUSIONS

The results indicated that the newly developed antibacterial self-etch adhesive can be combined with various bonding systems; achieved bond strengths were clinically more than satisfactory.

Antibacterial effect of an ozone device and its comparison with two dentin-bonding systems

Microorganisms remaining beneath restorations can cause secondary caries and pulp damage. Because of this, antimicrobial treatment could be useful. The aim of this study was to evaluate the antibacterial effect of the HealOzone device on Streptococcus mutans and to compare it with the already proven activity of two dentin-bonding systems. Thirty-five human molars were divided into 5 groups. Cavities were then cut into the teeth (n = 28 cavities per group). After sterilization, the teeth were left in broth cultures of 10(6) colony-forming units (CFU) ml(-1) of S. mutans at 36 degrees C for 48 h. The appropriate treatment followed (group A, control; group B, Clearfil SE Bond; group C, Clearfil Protect Bond; group D, 40 s of treatment with ozone; and group E, 80 s of treatment with ozone), and the cavities were then filled with composite resin. After 72 h, the restorations were removed, dentin chips were collected with an excavator, and the total number of microorganisms was determined. All treatments significantly reduced the number of S. mutans present compared with the control group. The antimicrobial effect of both bonding systems and treatment with 80 s of ozone was significantly higher than the 40 s ozone treatment. In conclusion, HealOzone and the bonding systems show striking antimicrobial effects against S. mutans.