Direct Contact Test Research Articles

Comparative Study of Antibacterial Activity of Five Luting Cements on Strains of Streptococcus mutans: An In Vitro Study

The purpose of the study was to evaluate and compare the antibacterial activity of five luting cements on Streptococcus mutans. Agar diffusion test (ADT) and direct contact test (DCT) were carried out to measure the antibacterial activity. In the DCT, the bacterial growth was highest in polycarboxylate cement, but zinc phosphate cement produced the maximum zone of inhibition in the ADT while no zone of inhibition was found in polycarboxylate cement.Purpose: To evaluate and compare the antibacterial activity of five luting cements (zinc phosphate, zinc polycarboxylate, glass ionomer, resin-modified glass ionomer and resin cements) on the strains of Streptococcus mutans using the direct contact test and agar diffusion test.Material and methods: For the agar diffusion test, three readings of the inhibition halo were recorded at 24 hours, 48 hours and 72 hours, respectively, and were repeated seven times for each material. In the direct contact test, the kinetics of the bacterial outgrowth were recorded at 650 nm in a temperature-controlled spectrophotometer for 24 hours, 48 hours, 72 hours and one week, respectively. The antibacterial activity of the tested specimens was analyzed using mixed ANOVA and Bonferroni post hoc tests (P < 0.05).Results: In the DCT, the bacterial growth was highest in polycarboxylate cement with mean (95% CI) growth of 0.58 mm and least in resin modified glass ionomer cement with mean (95% CI) growth of 0.26 mm. Although zinc phosphate cement showed the maximum zone of inhibition with mean value of 23.69 mm, zinc polycarboxylate cement did not produce any inhibition halo in the ADT.Conclusion: Resin-modified glass ionomer cement possessed the best antibacterial efficacy when the DCT was employed while zinc phosphate cement produced the best antibacterial property in the ADT. No zone of inhibition was found in polycarboxylate cement.

Antibacterial and Solubility Analysis of Experimental Phytotherapeutic Paste for Endodontic Treatment of Primary Teeth

Objective: To evaluate the antibacterial effect and the solubility of experimental root canal filling pastes containing the phytoconstituents terpineol and cinnamaldehyde. Material and Methods: Minimum Inhibitory Concentration (MIC) of each phytoconstituent was determined against Enterococcus faecalis. Five groups of antibiotic pastes based on zinc oxide were obtained by mixing: only terpineol, only cinnamaldehyde, terpineol and cinnamaldehyde combined, chlorhexidine (antibiotic control), and CTZ paste (control paste). Antibacterial activity was analyzed through direct contact test within 24 and 72 hours. Solubility was evaluated by spectrophotometry within 48 and 144 hours. Antibacterial activity data were analyzed descriptively, and solubility data was analyzed using ANOVA and Tukey tests (p<0.05). Results: The MIC obtained for terpineol and cinnamaldehyde were, respectively, 2000 µg/mL and 500 µg/mL. After 24h, only the terpineol paste did not inhibit E. faecalis growth. After 72h, all groups inhibited E. faecalis growth. After 48h, the highest solubility was verified in the terpineol paste (p<0.05), and no differences were detected among other groups (p>0.05). After and 144h, highest solubility was observed in the terpineol paste (p<0.05), followed by the CTZ paste (p<0.05). No differences were detected for cinnamaldehyde, terpineol+cinnamaldehyde and chlorhexidine pastes (p>0.05). Conclusion: Pastes containing cinnamaldehyde or terpineol+cinnamaldehyde showed antibacterial activity against E. faecalis similar to CTZ paste, with lower solubility.

Cytotoxicity, and antimicrobial and physicochemical properties of sealers incorporated with Uncaria tomentosa.

This study evaluated the cytotoxicity, the antimicrobial and physicochemical properties of root canal sealers incorporated with phytotherapic Uncaria tomentosa (UT). Unmodified AH Plus (Dentsply, DeTrey, Germany) and MTA Fillapex (Angelus, Londrina, Brazil) were used as controls. UT was incorporated into AH Plus and MTA Fillapex, at concentrations of 2% and 5% of the total weight of these sealers (w/w). Flowability, setting time, and solubility were evaluated following ISO requirements. The pH values were measured at periods of 12, 24, 48 hours, and 7 days. The antimicrobial activity of the sealers against Enterococcus faecalis was analyzed by both direct contact tests in freshly prepared sealers, and after 7 days. The cytotoxicity of the samples was evaluated by the MTT assay, to check Balb/c 3T3 cell viability. The statistical analysis was performed by one-way ANOVA and Tukey's test (p < 0.05). The incorporation of UT was associated with a decrease in flow, for both sealers, an increase in AH Plus setting time, increase in MTA Fillapex pH values, and solubility (after 14 days), for both sealers (p < 0.05). Regarding the antibacterial evaluation, bacterial reduction was reported after incorporation of UT into both AH Plus and MTA Fillapex, up to 7 days after handling of the material (P<0.05). UT incorporation decreased the cytotoxic effects of both AH Plus and MTA Fillapex sealers in a way directly proportional to their respective concentrations (p < 0.05). In conclusion, UT can be added to both sealers to reduce their cytotoxicity, and improve their antibacterial effects, without compromising their original physicochemical properties.

Development and Implementation of Enzymatic and Volatile Compound-based Approaches for Instantaneous Detection of Pathogenic Staphylococcus aureus

Staphylococcus aureus (S. aureus) has a mortality rate of up to 30% in developing countries. In contrast, the mortality rate of S. aureus in the U.S. is less than 5%. One reason for the six-fold increase in fatality in underdeveloped communities is lack of access to a rapid, accurate, and user-friendly diagnostic method to enable timely detection of these infections. The purpose of this experiment was to determine if enzymatic and volatile compound-based approaches would perform more quickly in comparison to existing S. aureus diagnostic methods and to evaluate these novel methods on accuracy. Further, we sought to implement them in a reusable 3D-printed instantaneous detection device. A combination of droplet transmission tests and direct contact tests were developed and evaluated to create a comprehensive method by which individuals can diagnose their condition as pathogenic S. aureus, incorrect use of device, or another infection. We hypothesized that the approaches developed in this study would perform more quickly than existing approaches. Ultimately, our device provided results in less than 30 seconds, which is much quicker than existing methods that take anywhere from 10 minutes to 48 hours based on approach. Statistical analysis of accuracy provides preliminary confirmation that our device based on enzymatic and volatile compound-based approaches can be an accurate and time-efficient tool to detect pathogenic S. aureus.

Creating Antibacterial Properties in Flowable Dental Composites by Incorporation of 3,4-dihydropyrimidin-2(1H)-ones

Objective: To investigate the antibacterial, mechanical, physical properties and water sorption of flowable dental composites containing 3,4-dihydropyrimidin-2(1H)-ones. Material and Methods: 3,4-dihydropyrimidin-2(1H)-ones was synthesized and the antibacterial activity of flowable dental composites containing 0-5 wt% 3,4-dihydropyrimidin-2(1H)-ones and also of their mechanical and physical properties on flowable dental composites were investigated. Flexural strength was measured by a three-point bending test. Compressive strength (CS), Water sorption (WS) and depth of cure (DOC) were investigated. The data were analyzed by One-way ANOVA test. The level of significance was determined as p<0.01. Results: The direct contact test demonstrates that by increasing the 3,4-dihydropyrimidin-2(1H)-ones content, the bacterial growth is significantly diminished (p<0.001). The average flexural strength results show that with increasing 3,4-dihydropyrimidin-2(1H)-ones until 3% in the composite, no significant difference was observed in flexural strength (p>0.001) and the mean of compressive strength results show no significant difference between 0-4% groups (p>0.001). The mean of water sorption and depth of cure results shows no significant difference between groups (p>0.001). Conclusion: Incorporation of 3,4-dihydropyrimidin-2(1H)-ones into flowable resin composites in 3% wt can reduce the activity of Streptococcus mutans.

Antibacterial and antifungal activity of an MTA-Based root canal sealer versus epoxy resin-based and methacrylate resin-based sealers

Aim: The purpose of this study was to compare the antibacterial and antifungal activity of MTA Fillapex with AH 26, AH Plus, and RealSeal root canal sealers. S. aureus, E. faecalis, and C. albicans were used as test microorganisms with the agar-diffusion test (ADT) and the direct contact test (DCT). &#x0D; Methodology: For the ADT, 48 Mueller-Hinton plates were divided into 3 groups according to the microorganism used. Each group was then divided into 4 subgroups according to root canal sealer. Mueller-Hinton and Sabouraud agar mediums were preferred, and inhibition zones were measured to determine the antimicrobial efficacy at designated intervals. In the DCT, 96-well microtiter plates were used. For each microorganism and each sealer, 8 consecutive wells were prepared vertically on the plate. Microbial suspensions were allowed to directly contact the sealers in each well for 1 hour at 37°C. Subsequently, microbial growth was spectrophotometrically measured at set intervals for the freshly mixed and set forms.&#x0D; Results: A statistically significant difference was found between the tested root canal sealers for antimicrobial effectiveness (p &lt; 0.05). According to the ADT results, all sealers had antimicrobial activity against the tested microorganisms. MTA Fillapex demonstrated satisfying results in the ADT against all microorganisms. In the DCT, MTA Fillapex inhibited bacterial and fungal growth in all freshly mixed and set forms. However, the set forms of AH 26 and AH Plus began to lose their antimicrobial activity on the tested microorganisms after a while.&#x0D; Conclusion: The results showed that the MTA-based root canal sealer MTA Fillapex may be a favorable alternative sealer against bacterial and/or fungal species in clinical practice.&#x0D; &#x0D; How to cite this article:&#x0D; Türkyılmaz A, Erdemir A. Antibacterial and antifungal activity of MTA-based root canal sealer versus epoxy resin-based and methacrylate resin-based sealers. Int Dent Res 2020;10(3):66-72. &#x0D; https://doi.org/10.5577/intdentres.2020.vol10.no3.1&#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Antimicrobial and physicochemical characterization of endodontic sealers after exposure to chlorhexidine digluconate

ObjectivesAssess the antibacterial, physical and chemical properties of AH Plus, BioRoot RCS and Pulp Canal Sealer (PCS) in contact with 2% chlorhexidine digluconate (CHX) used as final irrigant prior to root canal obturation. MethodsThe antimicrobial properties were investigated by direct contact tests for planktonic and biofilm growth of E. faecalis, S. mutans, S.epidermidis and S.aureus in vitro. The setting time, wettability, microhardness and surface roughness were also assessed. The sealers were studied in no contact, 1-minute (short-term) and continuous contact (long-term) with CHX. Chemical characterization of sealers was performed by scanning electron microscopy, X-ray diffraction analysis and Fourier-transform infrared spectroscopy after CHX or saline used as the last irrigant in an ex vivo tooth model and in endo training blocks. ResultsCHX increased the antibacterial activity of all the sealers investigated against planktonic bacteria and biofilms with PCS exerting the highest antimicrobial activity with and without the presence of CHX. The setting of AH Plus and BioRoot RCS was retarded, while for PCS accelerated in the presence of CHX. AH Plus and PCS were more hydrophilic after contact with CHX, whilst BioRoot RCS was hydrophobic in a time-dependent manner. The microhardness of sealers was compromised and the surface roughness increased after CHX exposure for AH Plus and BioRoot RCS, and decreased for PCS. CHX did not affect the sealers’ chemistry, but PCS that exhibited two extra phases. SignificanceCHX improved the antibacterial efficacy of endodontic sealers but further evidence is needed to confirm its suitability as a final irrigant prior to root canal obturation.

Effect of zinc oxide nanoparticles incorporated into tissue conditioner on antifungal, physical, and mechanical properties.

This study evaluated the antifungal, physical, and mechanical properties of tissue conditioner incorporated with different amounts of zinc oxide nanoparticles (ZnOnps) at different storage times (0, 7, and 14 days). Specimens of 0, 5, 10, 15 wt% ZnOnps, or 15 wt% nystatin incorporated into tissue conditioner were fabricated (control, 5Zn, 10Zn, 15Zn, and Nys). The direct contact test (n=6) was performed to evaluate the antifungal effect against C. albicans suspension. The penetration depth (n=6) and tensile bond strength (n=8) were evaluated following ISO 13139. The 15Zn significantly reduced C. albicans cell number compared with control at all storage times (p<0.001). The penetration depths and tensile bond strengths of the 5Zn, 10Zn, 15Zn, and Nys were not significantly different compared with control at all storage times (p>0.05). In conclusion, the 15Zn provides antifungal effect up to 14 days without adverse effects on penetration depth and tensile bond strength.

Development and properties of endodontic resin sealers with natural oils

ObjectivesTo synthesize and evaluate the physicochemical, antimicrobial, and cytocompatibility properties of experimental resin-based endodontic sealers containing butia or copaiba natural oils. MethodsExperimental groups contained butia (Butia capitata) at 0.5 % (B0.5), 1 % (B1), 2 % (B2), and copaiba (Copaifera spp.) at 0.5 % (C0.5), 1 % (C1), and 2 % (C2). The control group contained no added oils (experimental material, EM) and the commercial group was a methacrylate-based resin material (RealSeal™, SybronEndo Corporation, Orange, CA, USA). Degree of conversion, film thickness, setting time, flow, water sorption and solubility, and radiopacity were measured. Meanwhile, antimicrobial (modified direct contact test) and cytotoxicity assays of the experimental groups and controls were performed. One-way ANOVA was used to determine the effect of the independent variable (material) on the degree of conversion, film thickness, radiopacity, flow, setting time, water sorption and solubility, and cytotoxicity. For antimicrobial assays, data were analyzed using two-way ANOVA and Ŝidák’s test. ResultsThe experimental groups containing natural oils showed higher values of degree of conversion, and lowest water sorption and solubility. EM, B0.5, B1, B2, and RS showed similar film thicknesses. The flow values were statistically similar in all groups. The experimental groups showed adequate cell compatibility. Copaiba oil at 2% increased the antimicrobial effect after 1 and 24 h (p < 0.05). The incorporation of butia or copaiba resulted in a slight modification in some physicochemical properties of the experimental resin sealers. ConclusionNovel resin sealers containing natural oils are a promising alternative for endodontics, because of their good physicochemical properties, antimicrobial effects, and cytocompatibility when compared to a commercially available sealer. Clinical significanceEndodontic sealers containing butia or copaiba had satisfactory cytocompatibility, antimicrobial effects, and adequate physicochemical properties.

PCL/β‐AgVO3 nanocomposites obtained by solvent casting as potential antimicrobial biomaterials

AbstractThe adhesion of microorganisms on biomaterials can impair its effective application. The addition of antimicrobial agents is a promising alternative to overcome this limitation. In this work, films of polycaprolactone (PCL) and nanostructured β‐AgVO3 (SV) were produced by solvent casting with 0.1, 0.5, and 1.0 wt% of SV. The effect of SV on the structure of PCL was investigate using Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), Raman spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). The antimicrobial activity of the films against Staphylococcus aureus and Escherichia coli was evaluated by the agar diffusion method and by direct contact test. FTIR confirmed the presence of SV into the PCL films, with chemical interaction between them. SEM showed that SV nanorods were well dispersed and with good interfacial adhesion with PCL. XRD diffraction and Raman spectroscopy showed that the presence of SV increased the number of nucleation sites, reducing the size of crystallites and increasing the amorphous domains in the PCL matrix, consequently reducing crystallinity. This behavior was confirmed by DSC, which showed a reduction in the crystallinity with increasing SV content. Films with 1 wt% of SV showed antimicrobial activity against Staphylococcus aureus in direct contact test.

Invitro anti‑bacterial activity of diosgenin on Porphyromonasgingivalis and Prevotellaintermedia.

Diosgenin (Dios), a natural steroidal sapogenin, is a bioactive compound extracted from dietary fenugreek seeds. It has a wide range of applications, exhibiting anti-oxidant, anti-inflammatory and anti-cancer activities. However, whether the extracts have beneficial effects on periodontal pathogens has so far remained elusive. The aim of the present study was to investigate the anti-bacterial effects of Dios on Porphyromonas gingivalis (P. gingivalis) and Prevotella intermedia (P. intermedia) in vitro. The anti-microbial effect of Dios on P. gingivalis and P. intermedia was assessed by a direct contact test (DCT) and the Cell Counting Kit (CCK)-8 assay at 60, 90 and 120 min. In addition, counting of colony-forming units (CFU) and live/dead cell staining were used to evaluate the anti-bacterial effects. The results of the DCT and CCK-8 assays indicated that Dios had beneficial dose-dependent inhibitory effects on P. gingivalis and P. intermedia. The CFU counting results also indicated that Dios had dose-dependent anti-bacterial effects on P. gingivalis and P. intermedia. Of note, Dios had significant anti-bacterial effects on the biofilms of P. gingivalis and P. intermedia in vitro as visualized by the live/dead cell staining method. In conclusion, the present results demonstrated that Dios had a marked anti-bacterial activity against P. gingivalis and P. intermedia in vitro, both in suspension and on biofilms. The present study highlighted the potential applications of Dios as a novel natural agent to prevent and treat periodontitis through its anti-bacterial effects.

Evaluation of a Novel Endodontic Paste for Primary Teeth with Necrotic Pulp

Background: The ideal root canal filling for endodontic treatment of primary teeth with necrotic pulp must have antimicrobial activity, not cause tooth discoloration or interfere with the eruption of permanent successor teeth. This study aimed to evaluate physiochemical properties of a novel paste (CZ Paste) for endodontic treatment of primary teeth with necrotic pulp and compare its antimicrobial activity to Chloramphenicol, Tetracycline, Zinc oxide (CTZ) and Zinc Oxide eugenol (ZOE) pastes. Methods: CZ, CTZ and ZOE pastes were homogenized with eugenol at the time of testing. Fourier Transform Infrared spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) tests were performed. Antimicrobial activity was assessed using agar diffusion test (ADT), direct contact test (DCT) and bactericidal effect assessment against Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa. Results: FTIR showed that CZ paste has a similar profile to chloramphenicol spectrum and in DSC thermograms it demonstrated a slight change in endothermic transition temperature. In the ADT, CTZ paste and CZ paste presented similar inhibition zone diameters and were higher than ZOE paste (P Key words: Primary tooth, Pulpectomy, Root canal filling materials, Antibiotic paste, Bacteria.

Biocompatibility, induction of mineralization and antimicrobial activity of experimental intracanal pastes based on glass and glass-ceramic materials.

To evaluate the biocompatibility, induction of mineralization and antimicrobial activity of experimental intracanal pastes based on two glass and glass-ceramic materials. Calcium hydroxide (Ca(OH)2 ) paste was used as the positive control. The glass-ceramic powder [two-phased Biosilicate (BS-2P)] and F18 bioactive glass were mixed with distilled water (ratio 2:1), inserted in polyethylene tubes and implanted in the subcutaneous tissues of 16 rats. Empty tubes were used as negative control. After 7 and 30days (n=8), the rats were euthanized for haematoxylin-eosin, von Kossa, polarized light and osteopontin (OPN) immunolabeling analysis. Direct contact tests using a suspension of each paste were performed with Enterococcus faecalis planktonic cells to evaluate antimicrobial activity (24h of contact), in a pilot study. The number of CFUmL-1 was calculated for each group. The antimicrobial analysis data were submitted to one-way anova and Tukey tests, whilst biocompatibility and immunohistochemical data were submitted to the Kruskal-Wallis and Dunn tests (P<0.05). Most specimens of the control, BS-2P and Ca(OH)2 groups were associated with moderate inflammation seven days following implantation, whilst F18 was associated with moderate to severe inflammation, without differences amongst the groups (P>0.05). At 30days, most specimens of control, F18 and BS-2P groups had mild inflammation, whilst Ca(OH)2 had mild to moderate inflammation; however, no differences were determined amongst the groups (P>0.05). The fibrous capsule was thick at 7days, becoming thin at 30days. All pastes induced von Kossa-positive structures and were birefringent to polarized light. At seven days, the BS-2P group had significantly more OPN immunolabeling compared to the control and Ca(OH)2 groups (P<0.05). At 30days, the F18 group had significantly more OPN immunolabeling compared to the control and Ca(OH)2 groups (P<0.05). All pastes reduced the total number of E.faecalis; however, the reduction was only significant when comparing BS-2P and Ca(OH)2 groups to the control (P<0.05). Only calcium hydroxide eliminated E.faecalis. Experimental BS-2P and F18 pastes were biocompatible, stimulated biomineralization and induced significant OPN immunolabeling compared to Ca(OH)2 . Only the BS-2P paste demonstrated antimicrobial activity comparable to Ca(OH)2 .

New therapeutic system based on hydrogels for vaginal candidiasis management: formulation–characterization and in vitro evaluation based on vaginal irritation and direct contact test

The objective of the present research was to examine the possible usage of terbinafine loaded hydrogels for vaginal application as part of vaginal candidiasis treatment. Vaginal candidiasis belongs to the most frequent gynecological disorders. Various antifungal drugs are used for its treatment, with Terbinafine being one of them. In this study, new gel formulations were prepared for Terbinafine vaginal delivery. Natural polymers such as chitosan, sodium carboxymethylcellulose, and Carbopol were used for the development of Terbinafine vaginal gels. The developed gels were examined for their viscosity and spreadability, pH and mechanical properties. The most optimal formulations were further evaluated for their in vitro release behavior and antifungal activities. In further, the cytotoxicity and irritation inducing capacity of optimum gel formulations were evaluated. In vitro drug release studies demonstrated that terbinafine release was prolonged whereas anti-candida activity in several species showed the superiority of the gels compared to the marketed product. G-5 and G-8 gels did not cause lysis, hemorrhage and coagulation, therefore, classified as non-irritant. The optimal formulations were also studied for their stability, demonstrating that they were stable for 3 months.

Antimicrobial Effectiveness of Calcium Silicate Sealers against a Nutrient-Stressed Multispecies Biofilm.

Purpose: This study compared the antimicrobial efficacy of calcium silicate sealers (BioRoot RCS and Total Fill BC) and conventional sealers (AH Plus and Tubli-seal) against planktonic bacteria and a nutrient-stressed multispecies biofilm. Methods: Antimicrobial properties of freshly mixed sealers were investigated using the direct contact test (DCT) and a nutrient-stressed multispecies biofilm comprised of five endodontic strains. Antimicrobial activity was determined using quantitative viable counts and confocal laser scanning microscopy (CLSM) analysis with live/dead staining. The pH of the sealers was analysed over a period of 28 days in Hanks Balanced Salt Solution (HBSS). Analysis of variance (ANOVA) with Tukey tests and the Kruskal–Wallis test were used for data analysis with a significance of 5%. Results: All endodontic sealers exhibited significant antimicrobial activity against planktonic bacteria (p < 0.05). BioRoot RCS caused a significant reduction in viable counts of the biofilms compared to AH Plus and the control (p < 0.05), while no significant difference could be observed compared to TotalFill BC and Tubli-seal (p > 0.05). CLSM analysis showed that BioRoot RCS and TotalFill BC exhibited significant biofilm inhibition compared to Tubli-seal, AH Plus and the control (p < 0.05). BioRoot RCS presented with the highest microbial killing, followed by TotalFill BC and Tubli-seal. Alkalizing activity was seen from the onset by BioRoot RCS, TotalFill BC and AH Plus. After 28 days, BioRoot RCS demonstrated the highest pH in HBSS (pH > 12). Conclusions: Calcium silicate sealers exhibited effective antimicrobial properties. This was demonstrated by superior biofilm inhibition capacity and microbial killing, with strong alkalizing activity compared to epoxy-based and zinc oxide-eugenol-based sealers.

Antimicrobial properties, compressive strength and fluoride release capacity of essential oil-modified glass ionomer cements-an in vitro study.

This study was designed to investigate the antimicrobial properties, compressive strength and fluoride release capacities of high-viscous glass ionomer cements (GICs) after incorporation of cinnamon and thyme essential oils. Experimental-modified GICs were prepared by incorporation of thyme and cinnamon essential oils into the liquid phase of the cement at 5 and 10% v/v. Antimicrobial activity against selected microorganisms (Streptococcus mutans and Candida albicans) was done using direct contact test. Compressive strength of the four new formulations and control group was tested using a universal testing machine while fluoride ion release was measured by ion-selective electrode at 1, 7, 14 and 28 days. Data analysis and comparisons between groups were performed using factorial and one-way ANOVA and Tukey's tests. All newly formulated GICs exhibited significantly higher inhibitory effects against both Streptococcus mutans and Candida albicans growth when compared to conventional GIC (p < 0.05). Compressive strength of 5% cinnamon-modified GIC (MPa = 160.32 ± 6.66) showed no significant difference when compared with conventional GIC (MPa = 165.7 ± 5.769) (p value > 0.05). Cumulative fluoride-releasing pattern at days 7, 14, and 28 were 10% cinnamon-GIC > 5% thyme-GIC > 5% cinnamon-GIC > 10% thyme GIC > conventional GIC. Incorporation of 5% cinnamon oil into glass ionomer resulted in better antimicrobial effects against S. mutans and C. albicans and increased fluoride-release capacity without jeopardizing its compressive strength. The 5% cinnamon-modified GIC appears to be a promising alternative restorative material in ART technique.

ROOT CANAL IRRIGANT COMBINING SALVADORA PERSICA WITH SODIUM HYPOCHLORITE – ANTIMICROBIAL, TISSUE DISSOLUTION ,CHELATING ACTION & CHANGES IN CA/P OF ROOT DENTIN :IN VITRO STUDY

OBJECTIVE: Currently none of the irrigants used in endodontic therapy tested so far either alone or in combination could satisfy all criteria of ideal irrigant. Search for such a single agent which is more biocompatible along with other properties of irrigant continues. This study is aimed to evaluate pulp dissolution, antimicrobial activity, smear layer removing ability, and change in the Ca/P ratio of root dentin by using experimental formulation combining 3 % &amp; 5 % Sodium hypochlorite with 40% Salvadora Persica &amp; comparing it with 3 % Sodium Hypochlorite &amp; 17%EDTA Materials and Methods: Pulp dissolution: Human pulp tissue weighing 0.9g was dissolved in each experimental group G1:3%NaOCl,G2:3%NaOCl+40% S.persica, G3: 5%NaOCl +40% S.persica and weighed after the passage time of 10 min , 20min , 30 min. The difference in weight of the tissue sample before and after exposure to the test solution was assessed. Antibacterial activity: Antimicrobial efficacy of 3% NaOCl, 3% NaOCl + 40% S.Persica,5%NaOCl + 40% S.persica as experimental group against E.fecalis was assessed using direct contact test. Statistical Analysis for both the test was carried out using Kruskal Wallis and Post Hoc Mann Whitney Analysis Smear layer removal&amp; Ca/p ratio analysis: Single rooted premolars were divided in 3 groups (n=33) and irrigated with G1: 17% EDTA , 3% NaOCl, G2 : 3% NaOCl+ 40% S. persica, G3: 5% NaOCl + 40% S.persica. Each tooth was then split longitudinally. One half of sample from each group were subjected to scanning electron microscope to assess smear layer removal and second half for EDX analysis to check Ca/P ratio. Statistical Analysis: SEM – Kruskal Wallis and Post Hoc Mann Whitney EDX – ANOVA and Tukey’S HSD Post hoc Analysis RESULTS: • Pulp dissolution by freshly mixed G3 was superior to G1 &amp; G2. There is no difference in pulp dissolution efficacy of G1 &amp; G2. • No statistically significant difference was seen with respect to smear layer removal among the groups tested. EDX analysis showed significantly low Ca/P ratio for G1 compared to other groups and no statistically significant difference was seen b/w G2 &amp;G3 • In both the time interval tested (5 min, 10min) G3 showed maximum antimicrobial efficacy followed by G1 and G2 in terms of mean value. CONCLUSION: The combined formulation of 5% NaOCl + 40 % S.Persica was most effective root canal irrigant among the groups tested in terms of pulp dissolution, antimicrobial &amp;chelating action. 3% NaOCl + 40% Salvador persica was found to be as effective as 3% NaOCl and 17% EDTA. Experimental irrigants were found to be less erosive to root dentin in both combinations tested.

Highly translucent dental resin composites through refractive index adaption using zirconium dioxide nanoparticles and organic functionalization

ObjectivesFor dental resin composites, high translucency is important. Therefore, the aim of the study was to create a biocompatible and highly translucent resin-based composite, and to investigate the effect of material thickness on translucency. MethodsA biocompatible ORMOCER® resin matrix was reinforced with dental glass powder as fillers. To reach a high translucency, refractive index matching of the matrix and fillers was done in the two ways: (1) Highly refractive ZrO2 nanoparticles were incorporated into the resin. (2) The resin was modified via addition of 4-Methylthiophenol. The corresponding refractive indices were acquired on an Abbe refractometer (n = 5). In both cases, the dental glass powder was added and translucency of the resulting minifilled and nanohybrid composites were measured using spectral photometry (n = 5). Additionally, the translucency of the experimental composites was determined as a function of specimen thickness in the range 10 μm–2 mm (n = 5). One-way ANOVA was performed to determine the significant differences in various optical parameters among different amounts of modifications and thicknesses at α = 0.05. Furthermore, cytotoxicity tests (extract and direct contact tests) were conducted according to ISO 10993 to classify the biocompatibility of the composites (n = 6). ResultsThe translucency values of the composites with 47 wt.-% dental glass powder and a specimen thickness of 2 mm, could be increased from 26% up to 71% by increasing the refractive index of the matrix through incorporating ZrO2 nanoparticles. Moreover, it can also be increased to 67% via addition of 4-Methylthiophenol. Further results showed that the translucency significantly depended on the sample thickness following an exponential function. The effect of all tested parameters was significant among the materials (p < 0.001). The composites did not show any cytotoxic effect. SignificanceHighly translucent and biocompatible resin composites were developed. They show attractive properties for the use as dental enamel material in direct and indirect restorations.

Electrospun colourimetric sensors for detecting volatile amines

Volatile amines are present in our daily life as a result of chemical manufacturing, agriculture and farming, release by rotten food or exhalation under certain medical conditions or diseases. An efficient, fast and low-cost method for detecting these compounds is desired due to their often-toxic nature. The development of a highly sensitive electrospun colourimetric sensor for the detection of volatile amines is reported here. Composite microfibrous meshes were obtained by incorporating activated furan adducts (FAs) into electrospun polymer meshes. Volatile amines penetrate into the amorphous polymer matrix where the ring-opening reaction with FAs yields strongly coloured donor-acceptor Stenhouse adducts (DASAs), resulting in an easily observable visible mesh colour change. Different FAs were evaluated, including a highly reactive FA yielding 3rd generation DASAs. The colourimetric responses were assessed qualitatively and quantitatively by RGB (red, green and blue) colour analysis. The sensors showed a detection range with high sensitivity down to the low-ppb range. Additionally, the covalent attachment of FAs to a polymer backbone anchored them inside the fibres and successfully prevented leaching. Thus, the cytotoxic effect of leached FAs was eliminated, as shown by indirect and direct contact tests with human fibroblasts.

Synthesis of an anti-cariogenic experimental dental composite containing novel drug-decorated copper particles

Secondary caries is one of the most major cause for re-placement of dental composite restorations. Targeting the survival of cariogenic bacteria residing on the restoration surface may reduce this problem. The present study aims to evaluate the antibacterial potential as well as assess the physical and chemical properties of experimental dental composites containing novel drug-decorated copper particles (DDCP) as adjunct antibacterial filler particles. These were incorporated at concentrations of 0%, 0.5%, 0.10%, 0.20%, and 0.25% (w/w) into experimental composite consisting of methacrylate monomers and silanized silica fillers. RESULTS: Direct contact test revealed that the anti-cariogenic potential of experimental composites was more than the control groups. The cell viability assay showed no toxic effect on MC3T3-E1 cell lines in the MTT assay. The microhardness of experimental composites increased as the percentage of DDCP increased, however, the degree of cure was increased only up till the concentration of 0.20%. The release kinetics of the composites reveals that even after 28days there was a steady and slow release of copper particles signifying the sustained anti-cariogenic effect. CONCLUSION: The experimental composites have good anti-cariogenic potential, which was sustained for one month without any deleterious effect on the physical and chemical properties of resin dental composites.