Comparative Evaluation of Medicinal Plant Extracts and Antimicrobial Magistrals.

The in vitro antimicrobial activity of the active ingredient in antimicrobial magistral drug formulations and plant extracts used in folk medicine were investigated comparatively. Borax, sulfur colloid, hydrogen peroxide, benzoic acid, rivanol, brilliant green and plant extracts as active ingredients, namely: Helianthus tuberosus tuber-H2O (aqueous extract), Cydonia oblonga leaves-H2O, Allium porrum whole plant-H2O, Cistus laurifolius leaves-EtOH, Solanum muricalum-H2O, and Fumaria cilicica leaves-EtOH were studied to determine their antimicrobial activity against different bacteria and fungi (S. pyogenes, S. aureus, S. epidermidis, E. faecalis, K. pneumonia, H. influenza, P. aeruginosa, A. baumannii, E. coli, Candida albicans, C. tropicalis, C. parapsilosis, C. krusei) by using the microdilution method. The active ingredients and plant extracts showed different activities as MIC between 1->128 µg/mL. Brilliant green and rivanol as active ingredients had MIC values of 1 µg/mL against all tested microorganisms. C. oblonga leaves-H2O as well as C. laurifolius leaves-EtOH as plant extracts were indicated as having the highest antimicrobial effect in MIC value of 16 µg/ml against A. baumannii and S. pyogenes, respectively. On the other hand, F. cilicica leaves-EtOH and C. laurifolius leaves-EtOH showed the highest antifungal activity (MIC; 16 µg/mL).

Antibacterial, antifungal and enzyme inhibitory effects of selected plants from Turkey.

In this study, antibacterial, antifungal, antihyaluronidase, anticollagenase and antielastase activity of Hypericum bithynicum, Malva neglecta, Morus alba, Rubus discolor, Sambucus ebulus and Smilax excelsa were investigated. Methanol extracts of M. neglecta and R. discolor and all extracts of H. bithynicum were more active against Staphylococcus epidermidis. Similarly, water extracts of M. alba and S. ebulus were more active against Streptococcus pneumonia. Additionally, S. ebulus and S. excelsa had prominent antifungal activity on Candida albicans. Besides, methanol extract of M. neglecta and n-hexane extract of H. bithynicum were determined to have significant antihyaluronidase activity. Only R. discolor showed significant antielastase effect.

A comparative evaluation of Juniperus species with antimicrobial magistrals.

The objective of this study was to evaluate the in vitro bioactivity of the active ingredient in selected antimicrobial magistral drug formulations and plant extracts used in folk medicine, comparatively. The active ingredients of magistrals such as; boric acid, balsam of Peru, zinc oxide, Calendula tincture, thymol, resorcinol, crystal violet were used as well as fruit or leaf extracts of Juniperus excelsa (Je), J. sabina (Js), J. foetidissima (Jf), J. communis ssp. nana (Jcsn), and J. oxycedrus spp. oxycedrus ripe (Joso) to determine the antimicrobial activity against gram positive bacteria (S. pyogenes, S. aureus, S. epidermidis, E. faecalis), gram negative bacteria (K. pneumoniae, H. influenza, P. aeruginosa, A. baumannii, E. coli), and fungi (Candida. albicans, C. tropicalis, C. parapsilosis, C. krusei) by using microdilution method. The inhibition end point of the minimum inhibition concentrations (MICs) were determined as µ mL-1. The active ingredient and plant extracts have shown antibacterial and antifungal activities with a MIC values of 1->128µmL-1. The active ingredient crystal violet (MIC; 1 µ mL-1) as well as Je- fruit ethanol, Jf-leaf and fruit ethanol, Joso-leaf and fruit ethanol extracts (MIC; 16µ mL-1) have exhibited the highest antimicrobial activities (MIC; 16µ mL-1). Although ingredients of magistrals seem to exert similar antifungal activity against C. albicans, C. tropicalis, and C. parapsilosis (MIC; 32µmL-1), thymol and resorcinol were observed to be more active against C. krusei (MIC; 16µ mL-1). Extracts were more pronounced against P. aeruginosa, A. baumannii, and S. epidermidis (MIC ranging from 16 to 32). In the mine time, the extracts showed equal antifungal activity against C. albicans and C. parapsilosis (MIC; 16µ mL-1). In our study, antimicrobial activity of the natural compounds and ingredients of selected magistrals have found to be promising with MIC values of 16-32µ mL-1. According to the results of our antimicrobial activity studies, utilization of Juniperus extracts in antimicrobial magistral formulations can be suggested.

Antibacterial, antifungal and enzyme inhibitory effects of selected plants from Turkey.

In this study, antibacterial, antifungal, antihyaluronidase, anticollagenase and antielastase activity of Hypericum bithynicum, Malva neglecta, Morus alba, Rubus discolor, Sambucus ebulus and Smilax excelsa were investigated. Methanol extracts of M. neglecta and R. discolor and all extracts of H. bithynicum were more active against Staphylococcus epidermidis. Similarly, water extracts of M. alba and S. ebulus were more active against Streptococcus pneumonia. Additionally, S. ebulus and S. excelsa had prominent antifungal activity on Candida albicans. Besides, methanol extract of M. neglecta and n-hexane extract of H. bithynicum were determined to have significant anti-hyaluronidase activity. Only R. discolor showed significant anti-elastase effect.

Antimicrobial effect of the extracts from Hypericum perforatum against oral bacteria and biofilm formation.

CONTEXT: One traditional medicines, Hypericum perforatum L. (Hypericaceae), possesses several beneficial effects against depression, ulcers, dyspepsia, abdominal pains, burns, bacterial infections, migraine headaches, and sciatica. OBJECTIVE: The present study investigates the antimicrobial activity of the ethanol extract (HP-EtOH) of H. perforatum and its sub-extracts, namely n-hexane (HP-hexane), chloroform (HP-CHCl3), ethyl acetate (HP-EtOAc), n-butanol (HP-n-BuOH), and water (HP-H2O) extracts, against Streptococcus mutans, S. sobrinus, Lactobacillus plantarum, and Enterococcus faecalis. MATERIALS AND METHODS: For the evaluation of the antimicrobial activity, flowering aerial parts of H. perforatum were extracted with EtOH and then this extract was fractionated to obtain five sub-extracts in different polarities. Antimicrobial activities of HP-EtOH and its sub-extracts against Streptococcus mutans, S. sobrinus, L. plantarum, and E. faecalis were assessed by using colorimetric micro-well dilution at concentration ranges of 64-0.5 µg/ml as well as resazurin microplate and modified microtiter-plate assays between the ranges of 100 and 0.78125 µg/ml. RESULTS: According to the results of the present study, HP-H2O sub-extract displayed strong antibacterial activity (MIC values 8 µg/mL) against S. sobrinus and L. plantarum, and exerted moderate activity against S. mutans and E. faecalis at 32 and 16 µg/mL concentrations, respectively. Other sub-extracts also demonstrated antimicrobial activity against S. sobrinus at a concentration of 16 µg/mL. HP-EtOAc and HP-n-BuOH showed antimicrobial activity against L. plantarum and HP-EtOAc and HP-H2O were also active against E. faecalis at the same concentrations (16 µg/mL). CONCLUSION: According to the results, we suggest that H. perforatum could be employed as a natural antibacterial agent in oral care products.

Effects of Fixed and Removable Space Maintainers on Plaque Accumulation, Periodontal Health, Candidal and Enterococcus Faecalis Carriage.

OBJECTIVE: To evaluate the effects of space maintainers on plaque accumulation, periodontal health and oral microflora. SUBJECTS AND METHODS: The study participants comprised 38 patients aged 4-10 years requiring either fixed or removable space maintainers. Plaque index, gingival index, bleeding on probing index, candidal colonization and Enterococcus faecalis were recorded just before the application of space maintainers (T0) and during treatment at the 1st (T1), 3rd (T2) and 6th (T3) month. RESULTS: The gingival and bleeding on probing index scores increased significantly (gingival index from 0.20 ± 0254 to 0.54 ± 0417 and bleeding on probing index from 7.18 ± 9.946 to 18.07 ± 14.074) in the regions with fixed space maintainers at T3 (p < 0.01). The mean Candida counts also increased (for removable appliances from 1.90 ± 3.638 to 1.98 ± 3.318, p < 0.05, and for fixed appliances from 4.25 ± 4.587 to 4.52 ± 4.431, p < 0.001). The salivary E. faecalis counts at T3 also increased significantly with the use of fixed and removable appliances (for removable appliances from 5.93 ± 2.65 to 85.53 ± 34.1 and for fixed appliances from 4.95 ± 2.94 to 123.59 ± 29.51, p < 0.001). A positive correlation was found between the plaque (r = 0.67), gingival (r = 0.76) and bleeding on probing index scores (r = 0.76) and the candidal colonization for the fixed space maintainers (p < 0.01, p < 0.001). CONCLUSIONS: In this study, both fixed and removable space maintainers led to an increase in the number of microorganisms in the oral cavity as well as to increases in the periodontal index scores. Patients should be informed that space maintainers may serve as a source of infection and that special attention must be given to their oral hygiene.

Evaluation of bioactivities of chlorokojic acid derivatives against dermatophytes couplet with cytotoxicity.

In an attempt to find novel antifungal agents with improved activity, a series of compounds bearing 6-chloromethyl-3-hydroxy-2-substituted 4H-pyran-4-one moiety were synthesized and examined for their cytotoxic evaluation and antifungal activities against both standard and isolated dermatophytic fungal species Microsporum gypseum, Trichophyton mentagrophytes var. erinacei and Epidermophyton floccosum.

Design, synthesis and in vivo/in vitro screening of novel chlorokojic acid derivatives.

A series of novel Mannich bases of chlorokojic acid (2-chloromethyl-5-hydroxy-4H-pyran-4-one) were synthesized and their biological activities were investigated. Anticonvulsant activity results according to phase-I tests of Antiepileptic Drug Development (ADD) Program revealed that compound 13 was the most effective one at 4 h against subcutaneous pentylenetetrazole (scPTZ)-induced seizure test. Antimicrobial activities were evaluated in vitro against bacteria and fungi by using broth microdilution method. The antitubercular activities against Mycobacterium tuberculosis and M. avium were discussed with Resazurin microplate assay (REMA). The antimicrobial activity results indicated that compounds 1 and 12 (MIC: 8-16 µg/mL) showed higher activity against Gram negative bacteria while compound 12 had MIC: 4-16 µg/mL against Gram positive bacteria. Compound 1 was the most active one with MIC values of 8-32 µg/mL against fungi. Mannich bases also exhibit significant antitubercular activity in a MIC range of 4 to 32 µg/mL, especially compound 18 against M. avium.

Assessment of antimicrobial, insecticidal and genotoxic effects of Melia azedarach L. (chinaberry) naturalized in Anatolia.

In this study, antibacterial, antifungal, insecticidal and genotoxic activities of the fruit and leaf extracts of Melia azedarach of Turkish origin were evaluated for the first time. The antimicrobial activity was assessed against Gram (+) and (-) bacteria, four Candida species and three dermatophytic fungus (Trichophyton rubrum, Epidermophyton floccosum and Microsporum gypseum). The insecticidal activity of the methanolic fruit extract was performed against the larvae of Aedes aegpyti, Culex pipiens and Culex quinquefasciatus. The genotoxicity of this extract was evaluated against Drosophila melanogaster by somatic mutation and recombination test. The extracts showed higher antibacterial effect against Gram (-) strains (16-32 µg ml(-1) of minimal inhibition concentration, MIC), while the leaf extracts were more effective on Candida albicans (32 µg ml(-1)of MIC). The extracts did not exhibit insecticidal activity and genotoxicity. Total phenol and flavonoid contents of the extracts were determined spectrophotometrically, and the ethyl acetate extract of the leaves was the richest in total flavonoids.

Cytotoxicity, antiviral and antimicrobial activities of alkaloids, flavonoids, and phenolic acids.

OBJECTIVE: Some natural products consisting of the alkaloids yohimbine and vincamine (indole-type), scopolamine and atropine (tropane-type), colchicine (tropolone-type), allantoin (imidazolidine-type), trigonelline (pyridine-type) as well as octopamine, synephrine, and capsaicin (exocyclic amine-type); the flavonoid derivatives quercetin, apigenin, genistein, naringin, silymarin, and silibinin; and the phenolic acids namely gallic acid, caffeic acid, chlorogenic acid, and quinic acid, were tested for their in vitro antiviral, antibacterial, and antifungal activities and cytotoxicity. MATERIALS AND METHODS: Antiviral activity of the compounds was tested against DNA virus herpes simplex type 1 and RNA virus parainfluenza (type-3). Cytotoxicity of the compounds was determined using Madin-Darby bovine kidney and Vero cell lines, and their cytopathogenic effects were expressed as maximum non-toxic concentration. Antibacterial activity was assayed against following bacteria and their isolated strains: Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, Enterococcus faecalis, and Bacillus subtilis, although they were screened by microdilution method against two fungi: Candida albicans and Candida parapsilosis. RESULTS: Atropine and gallic acid showed potent antiviral effect at the therapeutic range of 0.8-0.05 µg ml(-1), whilst all of the compounds exerted robust antibacterial effect. CONCLUSION: Antiviral and antimicrobial effects of the compounds tested herein may constitute a preliminary step for further relevant studies to identify the mechanism of action.

Designing and application of a new medical instrument sterilization system using reactive oxygen species.

The aim of this study is to design and test a new medical sterilization system as an alternative to the techniques used in the sterilization of medical instruments. The designed system, which uses a new oxygen molecule allotrope (NOMA) in the reactive oxygen species, is developed as an alternative to the sterilization systems using other gases. The test was conducted on 12 different materials, each having a surface of 2 cm2, sterilized under 120 °C at 1 atm pressure for 20 min in the NUVE-OT 4060 sterilizer, and all surfaces were contaminated with a biological indicator Geobacillus stearothermophilus cultured in an incubator at 37 °C. Test samples in sterile Petri dishes were placed in a desiccator, and a sample was taken at 30-, 45-, and 60-min test periods and were placed on an agar medium and put in a Memmert incubator IN75 at 37 °C; in the controls conducted following 16-18 h of incubation period, no bacterial growth was observed in the newly designed system tested with gram positive bacilli; moreover, it was observed that the new system was 100% effective in sterilizing the microbes as no growth was observed on the samples. Within the scope of this study, a faster, low-cost, low-temperature, residue-free, and human and environmental friendly system was developed and tested for sterilization of medical devices compared to existing sterilization methods using NOMA.

A clinical and microbiological comparative study of deep carious lesion treatment in deciduous and young permanent molars.

The aim of this study was to compare one-visit indirect pulp treatment (IPT), two-visit IPT, and direct complete excavation (DCE) of deciduous and young permanent molars with deep carious lesions from clinical and microbiological points of view. One hundred thirty-five teeth (83 deciduous molars and 52 young permanent molars) were included in the study. The teeth were randomly selected and treated either with one-visit IPT, two-visit IPT, or DCE. For two-visit IPT, the final excavation was performed after a period of 3 months. The color, consistency, and humidity of the dentin at the cavity floor were recorded for clinical assessment, and dentin samples were obtained from all teeth. Dentin samples were microbiologically investigated for the total number of colony forming units, mutans streptococci, and lactobacilli. The results showed bacterial growth in 63.8% of the dentin samples in one-visit IPT, while in two-visit IPT, bacterial growth was observed in all of the samples (100%) after the first excavation. When the cavities were reopened before the final excavation, the number of samples with positive growth had decreased significantly (44.4%), and after the final excavation, the number of the samples with positive growth had decreased to 2.2%. In the DCE group, only 25.6% of the samples revealed bacterial growth. No statistical difference was found between deciduous and permanent molars in any of the treatment groups in terms of microbiologic results (p > 0.05). In conclusion, although none of the treatment methods completely eliminated the viable microorganisms during the initial excavations, a dramatic reduction in bacterial growth was detected during the treatment stages of two-visit IPT.

In vitro activities of voriconazole as a triazole derivative and caspofungin as an echinocandin were compared with those of some antifungal agents against Candida species isolated from clinical specimens.

We evaluated the in vitro activity of ketoconazole (KET), fluconazole (FLU), amphotericin B (AmpB), and flucytosine (FCU) in comparison to voriconazole (VOR) as a triazole derivative and caspofungin (CAS) as an echinocandin against 114 Candida spp. isolated from different cultures (blood, urine, sputum). The most common species of identified Candida were C. albicans (88), followed by C. parapsilosis (8), C. glabrata (7), C. tropicalis (6), C. famata (2), C. kefyr (2), and C. sake (1). The Clinical and Laboratory Standards Institute M 27-A method was used to evaluate the activity of antifungal agents. The minimal inhibitory concentrations of the strains were evaluated by RPMI 1640 medium using a microdilution method. Of 114 isolates, 100% were sensitive to AmpB, VOR, and CAS, 1.75% showed intermediate resistant to FCU also 0.87% showed intermediate resistant to FLU, and 2.63% were fully resistant to FLU and FCU. These results suggest that KET, AmpB, CAS, and VOR demonstrated excellent activity against all Candida spp. Taken together; these antifungal agents should be effective in the treatment of a broad range of Candida infections.

Antiviral and antimicrobial profiles of selected isoquinoline alkaloids from Fumaria and Corydalis species.

In the current study, 33 isoquinoline alkaloids belonging to protopine-, benzylisoquinoline-, benzophenanthridine-, spirobenzylisoquinoline-, phthalideisoquinoline-, aporphine-, protoberberine-, cularine-, and isoquinolone-types as well as 7 derivatives of them obtained from some Fumaria and Corydalis species growing in Turkey have been evaluated for their in vitro antiviral and antimicrobial activities. Both DNA virus Herpes simplex (HSV) and RNA virus Parainfluenza (PI-3) were employed for antiviral assessment of the compounds using Madine-Darby bovine kidney and Vero cell lines and their maximum non-toxic concentrations (MNTC) and cytopathogenic effects (CPE) were determined using acyclovir and oseltamivir as the references. Antibacterial and antifungal activities of the alkaloids were tested against Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, Bacillus subtilis, and Candida albicans by the microdilution method and compared to ampicilline, ofloxacine, and ketocanazole as the references. The alkaloids did not present any notable antibacterial effect, while they had significant antifungal activity at 8 microg/ml concentration. On the other hand, the alkaloids were found to have selective inhibition against the PI-3 virus ranging between 0.5 and 64 microg/ml as minimum and maximum CPE inhibitory concentrations, whereas they were completely inactive towards HSV.

The rapid sterilization of gutta-percha cones with sodium hypochlorite and glutaraldehyde.

The purpose of this in vitro study was to evaluate the effectiveness of sodium hypochlorite and glutaraldehyde for rapid sterilization of gutta-percha cones contaminated with Bacillus subtilis ATCC 6633. Cones were treated with either 2% glutaraldehyde or 2.5% sodium hypochlorite. The gutta-percha cones were sterilized with a 2.5% sodium hypochlorite solution throughout the test. Glutaraldehyde did not decontaminate the gutta-percha cones even after 15 minutes of contact. All positive controls showed positive results during the first 24 hours. Negative controls were followed up for 24 and 48 hours and demonstrated the efficiency of previous sterilization. No microbial growth was observed in the groups tested. Even though gutta-percha cones are usually sterile during storage, they can be easily contaminated if incorrectly manipulated. NaOCl at 2.5% concentration is an effective agent for decontamination of gutta-percha cones at no additional cost.

Flavonoids with anti-Helicobacter pylori activity from Cistus laurifolius leaves.

Cistus laurifolius flower buds are used traditionally in folk medicine against gastric ailments. In a prior study we showed that the chloroform extract of Cistus laurifolius had a potent anti-ulcer activity. It has been known that there is a causal relationship between peptic ulcer and Helicobacter pylori infection. Then in a previous study, we demonstrated that chloroform extract of Cistus laurifolius possessed a significant anti-Helicobacter pylori activity. We designed this study to isolate and define the active component(s) involved in the anti-Helicobacter pylori activity of the extract through activity-guided fractionation procedures. The chloroform extract was fractionated by using various chromatography techniques, i.e., Sephadex LH-20 column chromatography and preparative thin layer chromatography and six compounds were isolated (1-6). Each of these six compounds' anti-Helicobacter pylori activity was tested in vitro and was measured as minimum inhibition concentration (MIC) values by using agar dilution method. The compound 2 had the highest activity against Helicobacter pylori (MIC 3.9 microg/mL). Its chemical structure was elucidated as quercetin 3-methyl ether (isorhamnetin) by various spectroscopic techniques. We believe that the therapeutic effect of Cistus laurifolius in ulcer is at least partially related to its effect on Helicobacter pylori. We hope that the isolated flavonoid having anti-Helicobacter pylori activity ultimately can be utilized as an alternative or additive agent to the current therapy.

Antiviral and antimicrobial assessment of some selected flavonoids.

In the current study, the results of antibacterial, antifungal, and antiviral activity tests of four flavonoid derivatives, scandenone (1), tiliroside (2), quercetin-3,7-O-alpha-L-dirhamnoside (3), and kaempferol-3,7-O-alpha-L-dirhamnoside (4), are presented. Antibacterial and antifungal activities of these compounds were tested against Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, Bacillus subtilis, and Enterococcus faecalis, as well as the fungus Candida albicans by a micro-dilution method. On the other hand, both DNA virus Herpes simplex (HSV) and RNA virus Parainfluenza-3 (PI-3) were employed for antiviral assessment of the compounds using Madin-Darby bovine kidney and Vero cell lines. According to our data, all of the compounds tested were found to be quite active against S. aureus and E. faecalis with MIC values of 0.5 microg/ml, followed by E. coli (2 microg/ml), K. pneumoniae (4 microg/ml), A. baumannii (8 micro/g/ml), and B. subtilis (8 microg/ml), while they inhibited C. albicans at 1 microg/ml as potent as ketoconazole. However, only compound 3 displayed an antiviral effect towards PI-3 in the range of 8-32 microg/ml of inhibitory concentration for cytopathogenic effect (CPE).

In vitro susceptibility of Candida species isolated from blood culture to some antifungal agents.

Fungal infections are among the major causes of morbidity in cancer patients. In order to optimize the treatment of such patients, it is critical to determine the type of fungus causing infection as well as its susceptibility to antifungals. This study was undertaken to the study resistance of Candida spp. isolated from blood cultures of cancer patients to ketoconazole (KET), fluconazole (FLU), amphotericin B (AmpB), and flucytosine (FCU). A modified NCCLS M 27-A method was used to evaluate the activity of the species. Of the 56 Candida albicans isolates, 7 (12.5%) were resistant to FLU (MIC > or = 64 microg/ml), 6 (10.7%) were resistant to KET (MIC > or = 64 microg/ml) and 3 (5.3%) were resistant to FCU (MIC > or = 32 microg/ml). One (14.3%) of 7 C. parapsilosis isolates was resistant to FLU (MIC > or = 64 microg/ml). One (33.3%) of 3 C. tropicalis isolates was resistant to KET (MIC > or = 64 microg/ml). None of the C. guilliermondii or C. pelliculosa isolates was resistant to KET, FLU, AmpB, or FCU. Based on these results, AmpB is an effective antifungal agent that can be used against all Candida isolates.

Antibacterial, antifungal, and antiviral activities of the lipophylic extracts of Pistacia vera.

In the present study, antibacterial, antifungal, and antiviral properties of 15 lipohylic extracts obtained from different parts (leaf, branch, stem, kernel, shell skins, seeds) of Pistacia vera were screened against both standard and the isolated strains of Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Candida albicans and C. parapsilosis by microdilution method. Both Herpes simplex (DNA) and Parainfluenza viruses (RNA) were used for the determination of antiviral activity of the P. vera extracts by using Vero cell line. Ampicilline, ofloxocine, ketoconazole, fluconazole, acyclovir and oseltamivir were used as the control agents. The extracts showed little antibacterial activity between the range of 128-256 microg/ml concentrations whereas they had noticeable antifungal activity at the same concentrations. Kernel and seed extracts showed significant antiviral activity compared to the rest of the extracts as well as the controls.

Effects of disinfectants on resilient denture-lining materials contaminated with Staphylococcus aureus, Streptococcus sobrinus, and Candida albicans.

OBJECTIVES: Resilient denture-lining materials are more susceptible to microbial adhesion than are denture base acrylic resin. As denture hygiene is essential to maintain the serviceability of the denture, disinfectant solutions have been suggested as a method for effectively cleaning resilient liners. The aim of this study was to determine the effectiveness of four different disinfectant solutions on four different resilient lining materials contaminated with Staphylococcus aureus, Streptococcus sobrinus, and Candida albicans. METHOD AND MATERIALS: Three microorganisms (Sta aureus, Str sobrinus, and C albicans), four resilient lining materials (Tempo, Immediate, Flexacryl soft, Ufi Gel P), and four disinfectant solutions (5.25% sodium hypochlorite, 2% sodium hypochlorite, 5% Deconex, and 3.5% Savlex solutions) were investigated. The four resilient lining materials were contaminated with each of the microorganisms, then the disinfection tests were applied to detect the efficacy of disinfectant solutions on resilient denture base materials in an in vitro test. The specimens (n = 5, total = 240) were soaked for 5 minutes in each solution to disinfect the microorganisms. The control specimens (one of each material; n = 5, total = 60) were soaked in distilled water for 5 minutes. As a result, a reduction in microorganism counts was determined. The Kruskal-Wallis and one-way analysis of variance tests were used to analyze for significant differences among test groups at the level of significance. RESULTS: For all microorganisms, soaking in 5.25% sodium hypochlorite reduced the number of viable adherent microorganisms significantly compared to soaking in 2% sodium hypochlorite, which led to greater reduction than soaking either 5% Deconex or 3.5% Savlex. The use of 5.25% sodium hypochlorite in all groups is statistically significant. CONCLUSION: Disinfection of four different resilient denture-lining materials with 5.25% sodium hypochlorite solution was the most effective immersion technique. To achieve an efficient disinfection, the immersion time of the other disinfectant solutions could be increased.