In vitro Effect of Photodynamic Therapy with Curcumin and Methylene Blue Photosensitizers on Staphylococcus Aureus.

Statement of the Problem: Staphylococcus aureus (S.A) can colonize in the skin, nasal cavity, and oral cavity. In the oral cavity, it can cause dental caries and periodontal disease. Mouthwashes can be used as an adjunct to mechanical plaque control methods to decrease the load of oral microorganisms. Chlorhexidine (CHX) is a commonly used antimicrobial mouthwash with side effects such as changing the sense of taste, tooth discoloration, oral mucosal burning, allergy, and xerostomia. It also has adverse systemic effects, if swallowed. Purpose: This study aimed to assess the effect of photodynamic therapy (PDT) with curcumin and methylene blue (MB) photosensitizers and different laser parameters on S.A colony count. Materials and Method: In this in vitro experimental study, 99 samples of standard-strain S.A were subjected to PDT with curcumin and MB photosensitizers with/without irradiation of 660 and 445 nm laser with different exposure parameters, and CHX in 9 groups (n=11). The samples were cultured in microplates containing Mueller-Hinton agar, and the number of colony forming units (CFUs) was counted after 24 h of incubation at 37°C. Data were analyzed by the Kruskal-Wallis and Dunn tests. Results: The minimum colony count was noted in CHX group (CFUs=0) followed by MB and 660nm diode laser group irradiated for 100 s (CFUs=147.2727±169.35707). The difference in this respect was significant between MB+660nm diode laser for 100 s and other groups (p< 0.05) except for the MB + 660 nm diode laser for 60 s group. Conclusion: CHX is superior to laser for elimination of S.A. However, PDT with 660 nm diode laser + MB has considerable antimicrobial efficacy against S.A; increasing the duration of laser irradiation enhances the antimicrobial effect.

Comparison of the effect of photodynamic therapy with curcumin and methylene Blue on streptococcus mutans bacterial colonies.

BACKGROUND AND AIM: Streptococcus mutans (S. mutans) is a bacterium that colonizes in the mouth and is a common cause of dental caries and periodontal diseases. This bacterium comprises 70% of the bacteria in the dental plaque. Although tooth decay is a multifactorial complication, S. mutans biofilms are the main cause of cavitated carious lesions. Considering the importance of this microorganism, we aimed at investigating the effect of photodynamic therapy (PDT) using curcumin (CUR) and methylene blue (MB) photosensitizers on S. mutans. MATERIALS AND METHODS: In this in-vitro experimental study, first, samples of S. mutans were prepared in 110 test tubes and were randomly assigned to 11 groups after colony counting: 1) Positive control group, 2) Negative control group, 3) CUR extract group, 4) 460-nm laser group, 5) 460-nm continuous laser + CUR group, 6) 460-nm discontinues 50% duty cycle (DC) laser + CUR group, 7) 660-nm laser group, 8) 660-nm laser + MB group, 9) MB group, 10) dental light-curing group, and 11) chlorhexidine (CHX) group. After the intervention, cultivation was performed again in blood agar medium, and the bacterial colony-forming units per milliliter (CFU/ml) were counted again. Data were analyzed using analysis of variance (ANOVA) and Tukey's test. RESULTS: CHX and 460-nm low-level continuous laser + CUR had the highest and most significant effect on inhibiting the growth of S. mutans bacterial colonies and showed significant differences with other groups (P < 0.001). CONCLUSION: According to the results, MB- and CUR-mediated PDT can significantly eradicate S. mutans colonies.

In vitro comparison of the effect of photodynamic therapy with curcumin and methylene blue on Candida albicans colonies.

BACKGROUND AND AIM: Candida albicans (C. albicans) causes oral fungal infections. Considering the high prevalence of candidiasis, the toxicity of antifungal drugs, and the fungistatic property which develops drug-resistant species, the present study aimed to assess the effect of photodynamic therapy (PDT) with curcumin (CUR) and methylene blue (MB) photosensitizers and lasers with different exposure parameters on C. albicans colonies. MATERIALS AND METHODS: In this in-vitro experimental study, 150 samples of C. albicans standard strain (ATCC 10231) were examined using different combinations of CUR and MB photosensitizers with and without 460-nm and 660-nm laser irradiation with different exposure parameters in 15 groups of 10 samples each. The samples were cultured in microplates containing Sabouraud Dextrose Agar (SDA) medium, and the colony-forming units (CFU) were counted after 24 h of incubation at 37 °C. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's test. RESULTS: The maximum number of colonies was noted in the positive control group (CFU = 201,500 ± 42,093), while the minimum number was detected in the 460-nm laser+10.2% CUR group (CFU = 10,100 ± 2558), followed by the nystatin group (CFU = 22,300 ± 5578). There was a significant statistical difference between the 460-nm laser + CUR group and other studied groups (P < 0.0001). CONCLUSION: The 460-nm laser in combination with CUR has the maximum antifungal efficiency against C. albicans.

Comparison of the antimicrobial efficacy of photodynamic therapy with two mediators against Lactobacillus acidophilus in vitro.

BACKGROUND AND OBJECTIVES: Lactobacillus is a cariogenic microorganism. Different therapeutic approaches including photodynamic therapy (PDT) have been suggested for treatment of bacterial infection. The purpose of the current study was to compare the effects of PDT with Indocyanine green (ICG) and Methylene blue (MB) photosensitizers (PSs) on Lactobacillus acidophilus (L. acidophilus). MATERIALS AND METHODS: In this in-vitro experimental study, 84 samples of L. acidophilus (1 McFarland standard) were compared in 14 experimental groups including: MB, ICG, 660-nm laser, 808-nm laser (pulsed, 74s/continuous-wave, 37s), different combinations of lasers and PSs, Chlorhexidine (CHX) 0.2%, sodium hypochlorite (NaOCl) 2.5%, penicillin 6.3.3 and control groups. The samples were cultured in microplates containing blood agar culture medium. After incubation at 37 °C for 48 h, the colony forming units (CFUs) of L. acidophilus were counted and compared before and after therapeutic interventions. Data were analyzed using SPSS19 software program according to one-way ANOVA test. RESULTS: This study showed that the separate use of ICG, 660- and 808-nm lasers (pulsed, 74s/continuous-wave, 37s), and the combined use of 808-nm laser (pulsed, 74s/continuous-wave, 37s) and ICG have no significant inhibitory effect on L. acidophilus colonies (P > 0.05), whereas the separate use of MB and the combined use of 660-nm laser (continuous-wave, 37s/pulsed, 74s) and MB significantly inhibited the growth of L. acidophilus in comparison with the control group (p < 0.05). Likewise, CHX 0.2%, NaOCl 2.5% and penicillin 6.3.3 significantly inhibited the bacterial growth (p < 0.05). CONCLUSION: The results showed that separate use of MB and combined use of 660-nm laser and MB have a significant inhibitory effect on L. acidophilus growth.

Comparison of the bond strength of ceramics to Co-Cr alloys made by casting and selective laser melting.

PURPOSE: Considering the importance of metal-ceramic bond, the present study aimed to compare the bond strength of ceramics to cobalt-chrome (Co-Cr) alloys made by casting and selective laser melting (SLM). MATERIALS AND METHODS: In this in-vitro experimental study, two sample groups were prepared, with one group comprising of 10 Co-Cr metal frameworks fabricated by SLM method and the other of 10 Co-Cr metal frameworks fabricated by lost wax cast method with the dimensions of 0.5 × 3 × 25 mm (following ISO standard 9693). Porcelain with the thickness of 1.1 mm was applied on a 3 × 8-mm central rectangular area of each sample. Afterwards, bond strengths of the samples were assessed with a Universal Testing Machine. Statistical analysis was performed with Kolmogorov-Smirnov test and T-test. RESULTS: Bond strength in the conventionally cast group equaled 74.94 ± 16.06 MPa, while in SLM group, it equaled 69.02 ± 5.77 MPa. The difference was not statistically significant (P ≤ .05). CONCLUSION: The results indicated that the bond strengths between ceramic and Co-Cr alloys made by casting and SLM methods were not statistically different.

Effect of GLUMA desensitizer on the retention of full metal crowns cemented with Rely X U200 self-adhesive cement.

PURPOSE: Considering the importance of retention in the success and long-term clinical service of fixed partial dentures (FPDs) as well as the existing controversy regarding the effect of GLUMA desensitizer on the retention of full metal crowns cemented with RelyX U200 self-adhesive cement, this study aimed to assess the effect of GLUMA desensitizer on the retention of full metal crowns cemented using RelyX U200. MATERIALS AND METHODS: In this experimental study, 20 sound human premolars were prepared; a 0.5 mm chamfer finish line was prepared above the cementoenamel junction. The teeth were randomly assigned to two groups: a desensitizer group (n = 10, treated with GLUMA desensitizer) and a control (n = 10, no surface treatment). Full metal crowns were fabricated of base metal alloy and had a ring. All crowns were cemented with RelyX U200 and subjected to retention test by using a universal testing machine. The data were analyzed using SPSS version 20 and independent t-test. RESULTS: The mean tensile bond strength was significantly higher in the GLUMA desensitizer group (230.63 ± 63.8 N) compared to the control group (164.45 ± 39.3 N) (P≤.012). CONCLUSION: GLUMA desensitizer increases the tensile bond strength of RelyX U200 self-adhesive cement to dentin.

Effect of photodynamic therapy with two photosensitizers on Streptococcus mutants: In vitro study.

BACKGROUND AND OBJECTIVES: Streptococcus mutans (S. mutans) colonizes the oral cavity and causes dental caries and periodontal diseases. Considering the importance of the treatments that decrease pathogenic microorganisms, the aim of the present research was the assessment of the antimicrobial effect of Photodynamic Therapy (PDT) with Methylene Blue (MB) and Indocyanine Green (IG) photosensitizers on S. mutans. MATERIALS AND METHODS: In this In vitro experimental study, Sixty four caries-free first premolars were contaminated with 0.5 McFarland S.mutans suspension and were randomly assigned to 4 groups. The teeth in the first group were impregnated with 2% MB while the teeth in the second group were impregnated with 0.2% IG. The teeth in the first group were irradiated with continuous-wave 660nm dod laser with 40mw output power, energy density of 2.4J/cm2 and 100% duty cycle for 60s, while the teeth in the second group were irradiated with continuous -wave 810nm diode laser with 100mw out power, density energy of 6J/cm2 and 100% duty cycle for 60s in contact mode. In the third group, the teeth were suspended in 0.2% Chlorhexidine for 30s. The fourth group was considered as the control. The teeth were sampled before and after the interventions and the samples were incubated in Blood Agar for 24h. Afterwards, the number of S. mutans colonies were counted. Data were statistically analyzed by Kruskal-Wallis, Dunn's and Friedman tests. RESULTS: In the groups treated with a combination of MB and IG and laser irradiation and also in the Chlorhexidine group, the final number of S. mutans colonies equaled zero. In "MB and IG groups without laser irradiation", although the amount of microorganisms decreased, but the number of colonies did not reach zero. Pair comparisons by Dunn's test showed that there was a significant difference between "MB and IG groups without laser irradiation" and the other experimental groups p=0.03). CONCLUSION: PDT with MB and IG photosensitizers and also Chlorhexidine mouthwash, have the ability to completely eradicate S. mutans bacterial colonies.

Effect of surface treatments of porcelain on adhesion of Candida albicans.

Surface treatment of porcelain is required to minimize the adhesion of microorganisms to surfaces of the restoration. This study sought to assess the effects of 3 different porcelain surface treatments on adhesion of Candida albicans. This in vitro experimental study was conducted on 60 porcelain disks (10 × 3 mm) randomly divided into 4 groups of 15. The nonglazed group received no surface treatment; specimens in the other 3 groups were glazed in the furnace, overglazed with liquid glaze, or polished using a polishing kit. The specimens were washed, sterilized, and separately incubated with 350 µL of Candida albicans suspension for 24 hours. Specimens were then rinsed for 20 seconds and shaken in 1 mL of saline solution for 1 minute, and 20 µL of this suspension was cultured in a plate and incubated at 37°C for 48 hours. Candida albicans colonies were counted to assess the number of microorganisms adhering to each disk. Data were analyzed with the Kruskal-Wallis test. Statistically significant differences were found among the 4 groups in terms of C albicans adherence (P = 0.001). The nonglazed porcelain had the highest and the overglazed porcelain had the lowest mean adherence value. No statistically significant difference was noted between glazed and polished specimens. Based on the obtained results, overglazing resulted in the least adhesion of C albicans, and polishing provided a surface as smooth as a glazed surface.

Effect of photodynamic therapy with two photosensitizers on Candida albicans.

BACKGROUND AND OBJECTIVES: Oral candidiasis (OC) is an opportunistic infection of the oral cavity most commonly caused by Candida albicans (C. albicans). Considering the drawbacks of standard treatments with antifungal agents, this study sought to assess the efficacy of photodynamic therapy (PDT) with methylene blue (MB) and indocyanine green (ICG) photosensitizers against C. albicans. MATERIALS AND METHODS: In this in-vitro, experimental study, 130 samples of C. albicans standard suspensions were subjected to various combinations of MB and ICG photosensitizers with and without laser irradiation with different exposure parameters, nystatin and chlorhexidine (CHX) in 13 groups of 10. Samples were cultured in microplates containing Sabouraud dextrose agar medium and colony forming units (CFUs) were counted after 24h of incubation at 37°C. Data were analyzed by SPSS version 19.0, one-way ANOVA and Tamhane's test. RESULTS: The maximum number of CFUs was seen in the control group (mean of 214,200CFUs with a log value of 5.32) while the minimum values were noted in the laser (808nm and 100Hz PRR) plus ICG (mean of 13,460CFUs and log value of 4.12) and nystatin (mean of 13,940CFUs and log value of 4.14) groups. CONCLUSION: Within the limitations of this in vitro study, the results revealed that laser application (808nm, 100Hz PRR) plus ICG caused a significant reduction in C. albicans CFUs.

Comparison of Serum and Salivary Antioxidants in Patients with Temporomandibular Joint Disorders and Healthy Subjects.

OBJECTIVES: Temporomandibular dysfunction (TMD) is a group of disorders in the facial region and temporomandibular joint (TMJ). Biomarkers are assumed to play a role in pain and early detection of destruction. The aim of this study was to compare the saliva and serum antioxidant levels in patients with TMD and healthy subjects. MATERIALS AND METHODS: This case-control study was conducted on 28 TMD patients without pain, 28 TMD patients with pain and 28 healthy controls. The total antioxidant capacity of saliva and serum of patients was measured. Data were analyzed using ANOVA and Tamhane's test. RESULTS: The mean (±SD) total antioxidant capacity of serum (plasma TAC) was 0.8900 (±0.11627) mmol/L in TMD patients with pain, 1.2717 (±0.18711) mmol/L in TMD patients without pain and 1.7500(±0.18711) mmol/L in the control group. Based on ANOVA, the difference in this regard among the three groups was statistically significant (P=0.000). The mean salivary TAC was 1.34 (±0.06721) mmol/L in TMD patients with pain, 1.42 (±0.16677) mmol/L in TMD patients without pain and 1.35 (±0.11627) mmol/L in the control group. The difference in this respect among the three groups was not significant (P>0.05). CONCLUSION: The mean plasma TAC in TMD patients with/without pain was significantly lower than that in the control group but no significant difference was detected in salivary TAC among the three groups.

In Vitro Effect of Zingiber officinale Extract on Growth of Streptococcus mutans and Streptococcus sanguinis.

Background and Objectives. Tooth decay is an infectious disease of microbial origin. Considering the increasing prevalence of antibiotic resistance due to their overuse and also their side effects, medicinal plants are now considered for use against bacterial infections. This study aimed to assess the effects of different concentrations of Zingiber officinale extract on proliferation of Streptococcus mutans and Streptococcus sanguinis in vitro. Materials and Methods. In this experimental study, serial dilutions of the extract were prepared in two sets of 10 test tubes for each bacterium (total of 20). Standard amounts of bacterial suspension were added; 100ƛ of each tube was cultured on prepared solid agar plates and incubated at 37°C for 24 hours. Serial dilutions of the extract were prepared in another 20 tubes and 100ƛ of each tube was added to blood agar culture medium while being prepared. The mixture was transferred to the plates. The bacteria were inoculated on plates and incubated as described. Results. The minimum inhibitory concentration (MIC) was 0.02 mg/mL for S. mutans and 0.3 mg/mL for S. sanguinis. The minimum bactericidal concentration (MBC) was 0.04 mg for S. mutans and 0.6 mg for S. sanguinis. Conclusion. Zingiber officinale extract has significant antibacterial activity against S. mutans and S. sanguinis cariogenic microorganisms.

Candida albicans Adherence to Glass Ionomer Restorative Dental Material.

BACKGROUND AND AIMS: It is believed that adherence of Candida albicans to oral surfaces is a critical event in the coloni-zation and development of oral diseases such as candida-associated denture stomatitis. Although there is considerable infor-mation about the adherence of Candida albicans to buccal epithelial cells and prosthetic materials, there is very little infor-mation available about the adherence of Candida albicans to glass ionomer materials. The purpose of this study was to investigate the degree of Candida albicans adherence to glass ionomer restorative material. MATERIALS AND METHODS: In this experimental study adherence of Candida albicans strains was studied with and without human whole saliva. First, glass ionomer fragments were prepared; then yeast cells were inoculated and incubated with differ-ent incubation times. After incubation, the fragments were removed from the wells and stained with 0.1% calcofluor white. Adhesion was quantified by counting the total number of cells at 40, 80 and 120 minutes. The analysis of variance and Stu-dent's test were used to assess the significance of differences between the means. RESULTS: In the absence of saliva, the adherence of Candida albicans showed an increase, reaching a maximum at the end of the experiment (120 minutes). However, in the presence of saliva, the adherence of Candida albicans to glass ionomer significantly decreased. CONCLUSION: The presence of human whole saliva is an important factor in the adherence of Candida albicans to glass ion-omer restorative material.

The management of oral pemphigus vulgaris with systemic corticosteroid and dapsone.

BACKGROUND AND AIMS: Oral pemphigus vulgaris is a chronic autoimmune mucocutaneous intraepi-thelial disease that primarily affects patients over the age of fifty, resulting in mucosal ulceration and is a potentially life-threatening disease. The purpose of this study was to investigate the efficacy of dap-sone in combination with systemic corticosteroids to treat the oral lesions of oral pemphigus. MATERIALS AND METHODS: Twenty patients diagnosed with oral pemphigus were selected. Oral mani-festations were graded according to the severity of disease from 1 to 3. All patients were treated initially with systemic corticosteroids. Each was assigned to one of 4 groups according to their response to ther-apy. Patients who responded less than 50% healing of lesions began a trial of dapsone. After 4 weeks, signs and symptoms were recorded, and if a patient was lesion-free, the dapsone dosage was gradually tapered. RESULTS: Five patients with mild to moderate disease were treated with systemic corticosteroids alone. 15 patients with moderate to severe disease were treated with systemic corticosteroid and dapsone ther-apy. Of these, 10 patients had significant benefits, while 5 patients did not respond to dapsone adjuvant. Conclusions. The use of dapsone in combination with systemic corticosteroids is a useful method for treatment of oral pemphigus. CONCLUSIONS: The use of dapsone in combination with systemic corticosteroids is a useful method for treatment of oral pemphigus.

Effects of Low-level Laser in the Treatment of Myofascial Pain Dysfunction Syndrome.

BACKGROUND AND AIMS: Muscular pain in the facial region is the most common cause of facial pains. Myofascial pain dysfunction syndrome (MPDS) is one of the most important facial muscle disorders comprising of signs and symptoms including pain during function, tenderness in the muscles of mastication and restricted jaw movement. Due to the lack of an accepted therapeutic approach, the purpose of this paper was to find an effective treatment to decrease the pain of such patients. Considering the analgesic and anti-inflammatory action of laser therapy, the effects of low level laser (Ga-Al-As) in the treatment of MPDS patients referred to Tehran University of Medical Sciences Faculty of Dentistry, were investigated in the present study. MATERIALS AND METHODS: This study was a quasi-experimental research. Twenty-two MPDS patients were selected from those referred to Department of Oral Medicine, Tehran University of Medical Sciences Faculty of Dentistry. Clinical examination was performed at six stages in the following order: prior to the treatment, at 2 and 4 weeks after treatment, and monthly thereafter for a 3-months follow-up. All patients underwent low-level laser therapy for 4 weeks (12 sessions). Variables such as pain severity, pain of cheek region, pain frequency, tenderness of masticatory muscles, click, and mouth opening were evaluated at each stage. Numerical variables were investigated using Analysis of Variance test for repeated measures whereas ranking variables were studied by non-parametric Kruskal-Wallis test. RESULTS: At the end of treatment period, pain severity, pain of cheek region, pain frequency, tenderness of masseter, temporalis, medial pterygoid, and lateral pterygoid muscles showed significant improvement as compared with the commencement of any treatment which continued during the 3-months post-treatment (p<0.05). CONCLUSION: It was shown that low-level laser (Ga-Al-As) therapy had the efficacy to alleviate pain and decrease the tenderness of masticatory muscles among MPDS patients through a continuous and regular therapeutic program.

The comparison of efficacy of adcortyl ointment and topical tacrolimus in treatment of erosive oral lichen planus.

BACKGROUND AND AIMS: Oral lichen planus (OLP) is a common chronic mucocutaneous disease. Patients with atrophic and erosive lichen planus often have symptoms of soreness and need proper treatment. The main therapy of OLP has been the administration of topical or systemic corticosteroids. Potent topical corticosteroids have been increasingly prescribed in the treatment of erosive lichen planus. The purpose of this study was to compare the efficacy of adcortyl ointment (triamcinolone in orabase) with topical tacrolimus for the treatment of erosive oral lichen planus. MATERIALS AND METHODS: Sixty Patients with histopathologically confirmed oral lichen planus were enrolled in the study. The severity of lesions was scored from 0 to 5 according to the criteria described in a previous study. Patients were randomly given adcortyl (group A) and topical tacrolimus ointment (group B) and asked to apply the medication on dried lesions 4 times a day. The lesions were evaluated after 4 weeks of treatment. Visual analogue scale was used to assess the severity of pain before and after treatment. The severity scores were analyzed using the Kruskal-Wallis k-sample test. RESULTS: The average score of lesions improved from 3.4 to 1.5 in patients who received adcortyl ointment and from 3.2 to 1.2 in patients who received topical tacrolimus ointment. The differences between the im-provements in scores were not statistically significant in the two groups. The average pain severity in A and B groups was 8.2 and 7.8 at the beginning of treatment, and 3.5 and 3.2 at the end of treatment, respectively. There was a statistically significant reduction in pain severity in both groups. CONCLUSION: Topical tacrolimus is a safe and effective alternative therapy in the treatment of oral lichen planus.