Photodynamic inactivation of microorganisms present on complete dentures. A clinical investigation

Strategies for Preventing and Treating Oral Mucosal Infections Associated with Removable Dentures: A Scoping Review

Oral infections occur due to contact between biofilm rich in Candida albicans formed on the inner surface of complete dentures and the mucosa. This study investigated historical advances in the prevention and treatment of oral mucosal infection and identified gaps in the literature. Bibliographic research was conducted, looking at PubMed, Embase, Web of Science, and Scopus, where 935 articles were found. After removing duplicates and excluding articles by reading the title and abstract, 131 articles were selected for full reading and 104 articles were included. Another 38 articles were added from the gray literature. This review followed the PRISMA-ScR guidelines. The historical period described ranges from 1969 to 2023, in which, during the 21st century, in vitro and in vivo studies became more common and, from 2010 to 2023, the number of randomized controlled trials increased. Among the various approaches tested are the incorporation of antimicrobial products into prosthetic materials, the improvement of oral and denture hygiene protocols, the development of synthetic and natural products for the chemical control of microorganisms, and intervention with local or systemic antimicrobial agents. Studies report good results with brushing combined with sodium hypochlorite, and new disinfectant solutions and products incorporated into prosthetic materials are promising.

Modulation of implants PEEK to composite resin shear bond strength and surface roughness on pre-treatment with contemporary air abrasion techniques vs photodynamic therapy vs conventional diamond grit bur

AIM

The chief aim of the study was to determine/equate the surface roughness (SRa) and shear bond strength (BS) of pretreated PEEK discs with contemporary air abrasion techniques, photodynamic (PD) therapy by curcumin photosensitizer (PS) and conventional diamond grit straight fissure bur adhered to the composite resin discs.

MATERIAL AND METHOD

Two hundred discs of PEEK were prepared of 6 mm × 2 mm × 10 mm dimension. The discs were randomly divided into five groups (n = 40) for treatment, Group I: treatment with deionized distilled water (control group); Group II: PD therapy using curcumin PS; Group III: discs treated and abraded with air-borne particles (ABP) silica (30 μm particle size) modified alumina (Al); Group IV: ABP of alumina (110 μm particle size); and Group V: The PEEK were finished with 600-μm grit size straight diamond cutting bur installed in high speed hand-piece. The surface profilometer was used to evaluate the values of surface roughness (SRa) of pretreated PEEK discs. The discs were luted and bonded to discs of composite resin. The bonded PEEK samples were placed in Universal testing machine to evaluate shear BS. The type of BS failure for PEEK discs pre-treated with five regimes respectively was evaluated under stereo-microscope. The data was statistically analyzed using one-way ANOVA and the comparisons between mean values of shear BS were evaluated by Tukey's test (ρ≤0.05).

RESULTS

The PEEK samples pre-treated with diamond cutting straight fissure burs displayed statistically significant highest value of SRa values (3.258± 0.785 µm). Similarly, the shear BS was observed to be higher for the PEEK discs pre-treated with straight fissure bur (22.37±0.78 MPa). A comparable difference but not statistically significant difference was observed between PEEK discs pre-treated by curcumin PS and ABP-silica modified alumina (ρ ≥ 0.05).

CONCLUSION

PEEK discs pre-treated with diamond grit straight fissure bur displayed highest values of SRa and shear BS. It was trailed by ABP-Al pre-treated discs; whereas the SRa and shear BS values for the discs pre-treated with ABP-silica modified Al and curcumin PS did not show competitive difference.

Comparative effectiveness of interventions for the treatment of denture stomatitis: A systematic review with network meta-analysis

STATEMENT OF PROBLEM

Symptomatic denture stomatitis (DS) is a painful oral mucosal disorder that can impair quality of life in denture wearers. A complete cure of DS is difficult to achieve, and the most efficacious regimen to treat DS has not yet been conclusively established.

PURPOSE

The purpose of this network meta-analysis was to assess the comparative efficacy of interventions used for the treatment of DS.

MATERIAL AND METHODS

A search was conducted for trials published in Medline, Scopus, PubMed, and Cochrane Central Register of Controlled Trials from inception until February 2022 (PROSPERO Reg no: CRD42021271366). Network meta-analysis was performed on data from randomized controlled trials that assessed the comparative efficacy of any form of intervention for the treatment of DS in denture wearers. Agents were ranked according to their effectiveness in the treatment of DS based on outcomes using surface under the cumulative ranking (SUCRA).

RESULTS

A total of 25 articles were included in the quantitative analysis. Topical antifungal agents (risk ratio [RR]=4.37[95% confidence interval [CI]: 2.15,8.90), topical antimicrobial agents used along with systemic antifungal agents (RR=4.25[95% CI: 1.79,10.33]), systemic antifungal agents (RR=4.25[95% CI: 1.79,10.10]), photodynamic therapy (RR=4.25[95% CI: 1.75,8.98]), and topical plant products (RR=3.40[95% CI: 1.59,7.26]) were found to effectively improve DS. Microwave disinfection concurrently administered with topical antifungal agents (RR=7.38(95% CI: 2.75,19.81), microwave disinfection 7.38[95% CI: 2.75,19.81]), topical antifungal agents (RR=4.88[95% CI: 1.92,12.42]), topical plant products (RR=4.49[95% CI: 1.70,11.82]), systemic antifungal agents together with topical antimicrobial agents (RR=3.85[95% CI: 1.33,11.10]), topical antimicrobial agents (RR=3.39[95% CI: 1.17,9.81]), systemic antifungal agents (RR=3.37[95% CI: 1.21,9.34]), and photodynamic therapy or photochemotherapy (PDT) (RR=2.93[95% CI: 1.01,8.47]) were found to effectively resolve mycological DS. Topical antifungals ranked highest in the SUCRA ranking for clinical improvement, whereas microwave disinfection concurrently administered with topical antifungal agents ranked highest for mycological resolution. None of the agents demonstrated significant side effects except for topical antimicrobial agents which demonstrated altered taste and staining of oral structures.

CONCLUSIONS

Available evidence suggests that topical antifungals, microwave, and systemic antifungals are effective in the treatment of DS, but confidence in these findings is low because of the limited number of studies and a high risk of bias. Additional clinical trials are needed on photodynamic therapy, topical plant products, and topical antimicrobials.

Therapeutic efficacy of adjunctive photodynamic therapy in the treatment of denture stomatitis

BACKGROUND

The present report assessed the efficacy of curcumin-mediated photodynamic therapy (CUR-mediated PDT) as an adjunct to antifungal gel treatment by evaluating the salivary interleukin-6 (IL-6) and matrix metalloproteinases-8 (MMP-8) levels together with Candida species counts in denture stomatitis (DS) patients.

METHODS

In total, 50 DS subjects were randomly categorized into 2 groups: Group-1: subjects who received the antifungal gel treatment and Group-2: participants who received CUR-mediated PDT. The Sabourad Dextrose Agar and CHROMAgar were utilized for evaluating Candida species counts, while the Enzyme-Linked Immunosorbent Assay was employed to estimate the salivary levels of IL-6 and MMP-8. All clinical evaluations were performed at the baseline, 1 month, and 2 months.

RESULTS

In total, group-2 subjects showed a significant decrease in Candida albicans (C. albicans) counts on both follow-ups (i.e., 1-month and 2-month) than group-1 participants. C. krusei count also reduced in group-2 subejcts than group-1 participants at the 2nd follow-up as compared to the baseline, nevertheless, a slight increase in C. krusei count was noticed in group-2 subjects at the 2nd follow-up than the 1st follow-up. The salivary IL-6 and MMP-8 levels in both groups reduced significantly at both follow-ups than the baseline. According to the stepwise logistic regression analysis, no statistically significant correlation was observed between Candida species count and other parameters such as age and gender of the patient, duration of DS, and frequency of treatment(s).

CONCLUSION

CUR-mediated PDT is an efficaciousness therapeutic modality for alleviating Candida species counts on the surface of denture and the palatal mucosa, as well as improving the salivary IL-6 and MMP-8 levels in DS patients.

Efficacy of antimicrobial photodynamic therapy in disinfection of Candida biofilms on acrylic dentures: A systematic review

BACKGROUND

The aim of this systematic review was to critically analyze and summarize the currently available scientific evidence concerning antifungal efficacy of aPDT against Candida on acrylic surface.

METHODS

The focused question was: '"Is aPDT effective in minimizing the counts of Candida on acrylic dentures". A literature search was conducted interpedently on the following electronic research databases: PubMED/MEDLINE, Cochrane, Google Scholar and Embase. The MeSH terms used were: ((antimicrobial photodynamic therapy) OR (light) OR (laser) OR (photodynamic)) AND ((Candida) OR (denture stomatitis)) AND ((denture) OR (acrylic) OR (polymethylmethacrylate) OR (dental prosthesis)). Data was extracted from the studies and quality assessment was carried out using a modified version of the CONSORT checklist.

RESULTS

Eighteen in-vitro anti-microbial studies and 5 clinical studies were included. Twenty-two studies suggested that aPDT was effective in reducing the Candida count on acrylic dentures and one study did not have a significant effect. 19 out of 23 studies were graded as having 'medium' quality and 4 studies were graded as 'high'. Several photosensitizers, including methylene blue, porphyrin derivatives, toluidine blue-O and others were used. LED was the most popular light source used for photo-activation of the photosensitizers.

CONCLUSION

Within the limitations of this review, aPDT is effective in reducing Candida growth on acrylic dentures and may prove to be clinical effective in preventing or treating denture stomatitis. However, more long-term clinical research is required before its clinical efficacy can be determined.

Soft Denture liner and microbial disinfection with contemporary and conventional agents

AIM

The present study aimed to assess the effect of PDT, herbal and chemical disinfectants on the dental pathogen adherence to soft denture liner colonized with E. coli, C. Albicans, S.aureus, and S. mutans.

MATERIAL AND METHODS

A total of 20 samples of soft-lined removable acrylic complete dentures were fabricated and subjected to the American Type Culture Collection (ATCC) for the inoculation of E.coli, C.albicans, S.mutans and S.aureus in an in-vitro setup. The samples were then randomly divided into four groups and immersed in group 1: 5 µm of Rose Bengal (RB), group 2: Neem extract, group 3: Tea tree oil (TTO), and group 4: 0.12% CHX solutions respectively. Statistical analysis was accomplished by the SPSS 10 statistical software for Windows at a significance level p< 0.05. Two-way ANOVA and Tukey's multiple comparison test were used to analyze the data and compare the means and standard deviation values of CFU/mL (log10) for exposed E. coli, C. albicans, S aureus, and S. mutans.

RESULTS

Intragroup comparison indicated E.coli and C.albicans did not unveil a decrease in reduction CFU/mL (log10) when SDL irradiated with RB 5 µm. Whereas, CFU/mL (log10) values of S.aureus; 2.62±0.68 CFU/mL and S.mutans: 3.41±0.13 CFU/mL plunged significantly (p<0.05). Likewise, S. aureus and S. mutans CFU/mL (log10) strain values display reduction when treated with all four disinfectants while the count of C.albicans unveiled a significant plunge with CHX, TTO and neem extract except RB (p<0.05) CONCLUSION: 0.12% CHX and TTO have enhanced antimicrobial efficacy in reducing adhered bacterial colonies of E.coli, C.albicans, S.aureus, and S.mutans (CFU)/mL on a denture soft liner.

Efficacy of chemical and Photoactivated disinfectants against Candida Albicans and assessment of hardness, roughness, and mass loss of acrylic denture base resin

AIM

The present study aimed to assess the antimicrobial efficacy of hematoporphyrin derivative, sodium hypochlorite (NaOCl), glutaraldehyde (GaH), and a chlorhexidine (CHX) on mass loss (ML), microhardness, and surface roughness (Ra) of acrylic denture base colonized with C. Albicans.

MATERIAL AND METHODS

A total of 40 heat cure acrylic resin dentures were fabricated and inoculated by the American Type Culture Collection (ATCC) of C. Albicans in an in-vitro situation. Specimens were divided into four groups (n=10) based on the method of disinfection. Hematoporphyrin derivatives, 1% NaOCl, 2% GaH, and 4% CHX.The pre and post candida (CFU/ml) counts were recorded before and after immersion. ML, microhardness, and Ra of acrylic denture were also assessed. Statistical analysis was executed for CFU/mL (log10) for exposed C. Albicans by two-way ANOVA and Tukey's multiple tests (p>0.05). For normality of the data, Dunnet's Simultaneous test was performed.

RESULTS

In terms of candida strain analysis, pretreatment to posttreatment comparisons revealed a reduction in mean Candida count in all groups (p<0.05). The highest ML value after post candida disinfection of acrylic denture was observed in 2% GaH (1.587 ± 0.25) treated specimens. The least microhardness value was found in group 1 when treated with hematoporphyrin (0.97 ± 0.22 VHN) which was significantly different from other groups (p<0.05). Group 1 surface treated with hematoporphyrin derivate (1.84 ± 0.22 μm) showed the highest Ra values (p<0.05).

CONCLUSION

Acrylic denture base resin colonized with C. Albicans when treated with a chemical disinfectant of 4% chlorhexidine displayed the highest antimicrobial efficacy with reduced mass loss, less surface roughness, and maximum denture hardness.

Efficacy of contemporary agents on disinfection and surface roughness of polyetheretherketone implant abutments

AIM

The present study was designed to estimate the disinfection and surface roughness (Ra) of colonized (E. coli, C. albicans, S.aureus, and S. mutans) PEEK implant abutment disinfected with PDT, chemical, and herbal agents.

MATERIAL AND METHODS

The American Type Culture Collection (ATCC) inoculated E.coli, C.albicans, S.mutans, and S.aureus in an in-vitro scenario using 60 PEEK implant abutment samples provided by the manufacturer. Following that, the samples were distributed in four disinfection methods categories - group 1: 5mM Rose Bengal PS (RB), group 2: ultrasonic disinfection (UD), group 3: 2% glutaraldehyde (GaH), and group 4: tea tree oil (TTO). To scrutinize the data and compare the means and standard deviations of CFU/mL (log10) for exposed E. coli, Candida albicans, S.aureus, and S.mutans, a two-way ANOVA and Tukey's multiple comparison test were performed.

RESULTS

Specimens treated with 2% GaH, UD, and TTO validated a significant reduction in E. coli, C. albicans, S aureus, and S. mutans CFU/mL (log10) colonies. Intragroup assessment designated that there is no reduction in CFU/mL (log10) of E.coli and C.albicans when PEEK implant abutment specimens are irradiated with 5Mm RB. A decline is seen in values of S. aureus, and S. mutans microbial strains on treatment with all four cleansers while the computation of C.albicans and E.coli colonies unveiled significant reduction with GaH, UD, and TTO except RB (p<0.05). The results of Ra showed that PEEK fabricated implant abutment specimens, when treated with UD (3.472±0.561μm), displayed a significantly higher Ra value as compared to other analyzed cleansing methods.

CONCLUSION

. Disinfection with 2% glutaraldehyde and Tea tree oil showed maximum antimicrobial efficacy and lower Ra values for PEEK implant abutments colonized with bacterial strains of E.coli, C.albicans, S.aureus, and S.mutans.

Disinfection efficacy and fracture strength of PMMA denture-based polymer with chlorhexidine, PDT utilizing Rose Bengal and hematoporphyrin, and Er, Cr: YSGG laser

OBJECTIVE

The study aimed to assess and compare disinfection efficacy and fracture strength of PMMA based DBPs using chlorhexidine (CHX), PDT utilizing Rose Bengal (RB) and hematoporphyrin HPD, and Er,Cr:YSGG laser (ECL) induced antimicrobial action against in-vitro biofilms colonized with C.albicans, S.aureus, S. mutans, and E. coli.

MATERIAL AND METHODS

American Type Culture Collection (ATCC) of C.albicans, S.aureus, S. mutans and E. coli were cultured. Forty-eight PMMA-based denture base plates (DBPs) were prepared by heat-cure acrylic resin and contaminated by in-vitro biofilm under-stimulated in-vitro conditions. DBPs were treated with group1; ECL group 2; RB 5µm, group 3; HPD 500 mg/L and group 4; 0.12% CHX (controls) respectively, for the disinfection of biofilms. All photosensitizers (PS) were activated by LED at a different wavelength. Each contaminated DBP was sprayed on all its surfaces with the aforementioned photosensitizers and CHX. One-way analysis of variance (ANOVA) was used to test the efficacy of disinfection and fracture load testing. Tukey multiple comparison tests were performed to compare means of CFU/mL (log10) for exposed E. coli, C. albicans, S aureus, and S. mutans.

RESULTS

Specimens in group 1 disinfected with erbium laser, group 3 disinfected with HPD, and group 4 sterilized with chemical disinfection were effective in decreasing bacterial load CFU/mL (log10) against C.albicans, S. aureus, S.mutans, and E. Coli (p>0.05). Intergroup comparison demonstrated ECL, CHX and HPD demonstrated a comparable reduction against C.albicans and S.aureus (p>0.05). Similarly, S.mutans and E.coli were sensitive against all experimental groups (p>0.05). no significant difference in fractural load analysis among the different investigated groups was noted (p>0.05).

CONCLUSION

ECL and HPD photosensitizer revealed a significant reduction in CFU/ml of exposed viable colonies of C.albicans, S.aureus, S. mutans, and E. coli comparable to 0.12% CHX mediated disinfection of PMMA-based DBPs. Irrespective of the type of disinfection no influence of disinfection was noted on the fracture load of PMMA DBPs.

Shear bond characteristics and surface roughness of poly-ether-ether ketone treated with contemporary surface treatment regimes bonded to composite resin

AIM

To evaluate and compare the influence of contemporary surface treatments of air abrasions, sulfuric acid, and Photodynamic therapy (PDT) on the adhesive bonding and surface roughness of Poly-ether-ether-ketone (PEEK) bonded to resin composite.

MATERIAL AND METHODS

One hundred and fifty PEEK (disc-shaped) specimens of 10 mm diameter and 2mm thickness were prepared. Specimens were subjected to the following surface treatments, Control (no treatment), PDT, air abrasion using Alumina particles (110 μm) (AA-AP), Sulfuric acid (SA), and air abrasion using diamond particles (10-20 μm) AA-DP. Surface roughness (Ra) of treated samples were evaluated using surface profilometer. Universal testing machine was used to evaluate shear bond strength after composite resin build-up. Stereomicroscope was utilized for failure analysis of de-bonded samples of all five groups. Statistical analysis was performed utilizing one-way analysis of variance (ANOVA) to measure means and standard deviations of SBS among studied groups and the means of SBS were paralleled by Tukey multiple comparison tests (p>0.05).

RESULTS

The highest SBS was observed by 98% SA (19.25 ± 0.68 MPa). While specimen treated with PDT (11.69 ± 0.12 MPa) showed the lowest SBS. PEEK surface, treated with PDT and AA-DP demonstrated comparable SBS (p>0.05). PEEK when pretreated with 98% SA (2.658 ± 0.658μm) exhibited a significantly higher Ra value as compared to other surface-treated groups (p< 0.05).

CONCLUSION

PEEK surface treated with SA showed the highest SBS and surface roughness compared to other groups. Surface roughness of PEEK treated with PDT, AA-AP, and AA-DP demonstrated no difference in Ra. PEEK surface treatment technique should be further investigated to develop reliable adhesive resin bonding.

Influence of adjunctive non-surgical peri‑implant therapy on clinical and salivary cytokine profile in obese patients

AIM

The present study aimed to evaluate the impact of Photodynamic therapy (PDT) and Er,Cr:YSGG laser (ECL) adjunct to nonsurgical mechanical debridement (NSMD) in comparison to conventional NSMD in overweight individuals with peri‑implant disease on peri‑implant inflammatory parameters and cytokine levels of IL-6 and TNF-α in Peri-implant crevicular fluid (PICF) MATERIALS AND METHODS: Recruitment of volunteers was performed from the outpatient department according to predefined inclusion and exclusion criteria. Group 1 consisted of obese participants who underwent peri‑implant mechanical debridement (MD); group 2, obese participants who experienced MD adjunct to ECL, and in group 3, obese participants were treated with MD and adjunct PDT. Clinical periodontal parameters, plaque index (PI), bleeding index (BI) and probing depth (PD) along with crestal bone loss (CBL) were assessed at baseline, 3 months, and 6 months. PICF was collected to evaluate the levels of IL-6 and TNF-α. Kruskal-Wallis and Bonferroni post hoc test were employed for the comparison of peri‑implant inflammatory parameters and PICF cytokine profiles among the study groups.

RESULTS

Clinical peri‑implant parameters (PI, BI and PD) at baseline among subjects in group 1, group 2 and group 3 were comparable (p > 0.05). At 3 months follow up, mean scores of peri‑implant PI, BI, and PD (P <0.05) in group 1 (control) were significantly higher compared to group 2 (ECL) and 3 (PDT) (p < 0.05). At 6 months follow-up, PI and BI mean scores among groups 1, 2, and 3 were comparable (p>0.05). At 6 months participants in groups 2 and 3 noted significant difference (p<0.05) compared to baseline with no difference noted in the control group (p>0.05).

CONCLUSION

Photodynamic therapy and Er, Cr: YSGG adjunct to NSMD demonstrated significant improvement in peri‑implant inflammatory parameters in obese individuals. Multicentric clinical trials are suggested to extrapolate the findings of the present study.

CLEANING OF REMOVABLE DENTAL PROSTHESES - A SYSTEMATIC REVIEW

Objectives The aim of this systematic review was to provide an overview of the scientific evidence available from prospective clinical studies regarding denture hygiene interventions. Therefore, investigations addressing the efficacy of removing microorganisms and biofilms formed on the surface of removable dental prostheses (RDPs) and denture base materials in situ and their impact on the properties of denture base materials, such as color stability, surface roughness, and dimensional stability, were included. Methods A systematic literature search was conducted from June 1975-May 2020 and included articles published in English that have been indexed in the digital archives of PubMed and Cochrane (including PubMed, Embase, ICTRP, CT.gov). A complementary manual search of the initially retrieved studies was conducted. Inclusion criteria comprised prospective clinical trials with a minimum of ten participants investigating (1) approaches and methods to remove biofilms formed on the surface of RDPs and denture base materials in situ and/or (2) the influence of these biofilms on denture base materials. A total of forty-four studies were included in this systematic review, which was registered in the PROSPERO database (CRD42020189649). Results and Conclusions Data gathered from the systematic review indicate that the combined use of chemical and mechanical denture hygiene interventions is significantly more effective than single cleaning approaches. Only limited evidence is available from clinical studies regarding the effect of denture hygiene interventions on the properties of denture base materials.

Efficacy of Rose Bengal and Curcumin mediated photodynamic therapy for the treatment of denture stomatitis in patients with habitual cigarette smoking: A randomized controlled clinical trial

BACKGROUND

Cigarette smoking in conjugation with bad oral hygiene is considered a typical predisposing factor for many oral diseases including denture stomatitis. This study investigated the effect of Rose Bengal (RB)-and Curcumin (CUR)-mediated photodynamic therapy (PDT) in comparison with nystatin therapy in the intervention of denture stomatitis in cigarette smokers.

METHODS

Overall, 45 habitual cigarette smokers aged ~58 years having denture stomatitis were categorized into three groups: Group-I - RB-mediated PDT, Group-II - CUR-mediated PDT, and Group-III - Nystatin therapy. The primary outcome of the interest was: counts of Candida colony from denture surface and palatal mucosa, calculated as CFU/mL, whereas the prevalence of Candida species determined in 3 research groups comprised the secondary outcome. Oral swab specimens were gathered from the denture surfaces and palatal mucosa. All clinical assessments were performed at baseline, 6 weeks, and 12 weeks.

RESULTS

C. albicans was the most prevalent yeast identified on both denture surfaces and palatal mucosa, followed by C. tropicalis and C. glabrata. A considerable decrease in the CFU/mL scores were observed in Group-I and Group-II at the end of the interventions and on the 12-week follow-up (p<0.05). Group-I, II, and III demonstrated clinical efficacy rates of 53%, 51%, and 49%, respectively.

CONCLUSION

CUR-and RB-mediated PDT was found to be as effective as topical Nystatin therapy for the intervention of denture stomatitis among cigarette smokers.

Efficacy of porphyrin derivative, Chlorhexidine and PDT in the surface disinfection and roughness of Cobalt chromium alloy removable partial dentures

AIM

The present study aimed to evaluate the effect of different cleansers and photodynamic therapy (PDT) on disinfection of Co/Cr removable partial denture colonized with C. albicans, S.aureus and S.mutans.

MATERIAL AND METHODS

Twenty-five Co/Cr removable partial dentures were constructed. and inoculated by American Type Culture Collection (ATCC) of Candida albicans, S.aureus, and S.mutans in an in-vitro setup. Co/Cr removable partial dentures were randomly allocated into five groups and framework was immersed in 15 mL of contaminated culture medium broth. Based on the cleansing method, disinfected dentures in group 1 were cleansed with porphyrin derivative; group 2 was exposed to 0.12% chlorhexidine digluconate; samples in group 3 and group 4 were subjected to sodium perborate enzyme and citric acid respectively. Through a surface analyzer, the surface roughness of Co/Cr and methacrylate resin was measured in 3 different zones in micrometers before and after disinfection. Two-way ANOVA and Tukey's test was used to analyze the data. Levene test was used to assess the normal distribution of data. Significance level p< 0.05 RESULTS: The results of metal roughness displayed that Co/Cr used as an alloy did not exhibit significant difference when exposed to different chemical disinfectants and photosensitizer (p > 0.05). Similarly, surface roughness (Ra) of heat polymerized acrylic resin using cleansers and PDT demonstrated no significant difference. Intergroup comparison showed that, hematoporphyrin derivative displayed comparable cleansing property against S. aureus, C.albicans, and S. mutans compared to to 0.12% CHX digluconate (p>0.05). The intragroup comparison showed hematoporphyrin derivative and CHX were equally effective against all bacteria (p>0.05).

CONCLUSION

CHX digluconate and hematoporphyrin derivative demonstrated high antimicrobial activity against S.aureus, S.mutans, and C.albicans with minimum Ra of an acrylic denture and Co/Cr metallic framework.

Disinfection of acrylic denture resin polymer with Rose Bengal, Methylene blue and Porphyrin derivative in photodynamic therapy

AIM

The study aimed to assess the effect of in-vitro chlorhexidine and antimicrobial photodynamic therapy (aPDT) disinfection protocols against acrylic resin specimens colonized with S. mutans, S. aureus, E. coli, and C. albicans.

MATERIAL AND METHODS

Reference strains of S. mutans, S. aureus, E. coli, and C. albicans were tested. Sixteen blocks of acrylic specimens were prepared by heat-cure acrylic resin and contaminated by in-vitro biofilm growth. Specimens in group 1, group 2 and group 3 were treated with Rose Bengal (RB), methylene blue (MB) 500 mg/L and porphyrin derivative (PD) 5 ml respectively, for the sensitization of biofilms. All photosensitizers (PS) were activated by LED at different wavelength. CHX was prepared in sterile distilled water and applied for 60 s. Each contaminated specimen was sprayed on all its surfaces with the aforementioned photosensitizers and control CHX. One-way analysis of variance (ANOVA) model was used to test the effect of the treatments and Tukey multiple comparison tests to compare means OF CFU/mL (log10) for exposed E. coli, C. albicans, S aureus, and S. mutans RESULTS: Specimens treated with 0.12% CHX (control) demonstrated a significant reduction in CFU/mL (log10) for exposed E. coli; 2.04±0.07 CFU/mL, C. albicans; 2.09±0.85 CFU/mL, S aureus; 3.04±0.11 CFU/mL, and S. mutans; 2.54±0.91 CFU/mL. The intragroup comparison revealed E.coli did not exhibit a decrease in reduction CFU/mL (log10) when acrylic resin irradiated with RB 5 µm. Whereas, CFU/mL (log10) values of S.aureus; 3.62±0.68 and S.mutans; 3.41±0.13 plummeted (p<0.05). Intergroup comparison showed E.coli values to display comparable reduction when disinfected with MB 500 mg/L and 0.12% CHX; 3.16±0.34 and 2.04±0.07 CFU/mL (log10) (p<0.05).

CONCLUSION

Photosensitizers (RB, MB, PD) are selective in reducing bacterial count on acrylic resin blocks. CHX was found to be effective against all bacteria E.coli, C.albicans, S.aureus, and S.mutans at a concentration of 0.12%.

Photodynamic Therapy for Biomodulation and Disinfection in Implant Dentistry: Is It Feasible and Effective?

Dental implants are the most common rehabilitation and restorative treatment used to replace missing teeth. Biofilms adhere to implant surfaces to trigger implant-associated infection and inflammatory response. Clinically, the biofilm induces a local host response with the infiltration of phagocytic immune cells. The pro-inflammatory surroundings set off osteoclastogenesis, which leads to the septic loosening of the implant. The standard of dental care for implant-associated infection relies on a combination of surgery and antimicrobial therapy. Antimicrobial photodynamic therapy is a noninvasive and photochemistry-based approach capable of reducing bacterial load and modulating inflammatory responses. In this review, we explore the photobiomodulation and disinfection outcomes promoted by photodynamic therapy for implant infections, highlighting the quality of evidence on the most up-to-date studies, and discuss the major challenges on the advance of these therapeutic strategies.

Treatment of oral fungal infections using photodynamic therapy: Systematic review and meta-analysis

OBJECTIVES

This systematic review evaluated the evidence for the effectiveness of Photodynamic therapy (PDT) in treating oral fungal infections, as an alternative to conventional antifungal medications.

METHODS

Five randomized control trials (168 participants) comparing the treatment of oral fungal infections using met with our inclusion criteria. Clinical and microbiological improvement was assessed by random-effects meta-analysis. Methodological quality assessment and heterogeneity were performed using peer-reviewed criteria. PROSPERO registration: CRD42017076.

RESULTS

PDT showed statistically non-significant increased clinical efficacy (risk ratio (RR) = 1.47 [95% confidence interval (CI), 0.68; 3.17]; three studies, n = 108 participants, I² = 50%) and mycological efficacy (mean difference (MD) = 0.54 [95%CI, -0.71; 1.79]; three studies, n = 100; I² = 39%) at 30 days, as compared with conventional antifungal therapy. Lack of standardization of treatment parameters and variability in the assessment of outcomes was observed across the studies. All included studies had a moderate to low risk of bias.

CONCLUSIONS

PDT showed comparable effectiveness at treating oral fungal infections, particularly denture stomatitis. The small number of studies in this review, small sample size and variability of methods and outcome measures across studies, highlight the need for more standardized studies with longer follow-up periods to enable recommendation of PDT as an alternative to conventional antifungal therapy.

Fluorescence spectroscopy of Candida albicans biofilms in bone cavities treated with photodynamic therapy using blue LED (450 nm) and curcumin

Fluorescence spectroscopy may assisst in the diagnosis and control of infectious processes associated with bone lesions of the oral cavity. The aim of this study was to analyze, through fluorescence spectroscopy, Candida albicans biofilms formed in artificial bone cavities treated with photodynamic therapy (PDT) mediated with 450-nm blue light-emitting diode (LED) and curcumin. Another aim of this study was to analyze the existence of a correlation between the effectiveness of the photodynamic treatments and the fluorescence spectroscopy images. Artificial bone lesions (n = 40) were made in bovine bones and inoculated with standard suspensions of Candida albicans (ATCC 18804) for biofilm formation (14 days / 36 °C ± 1 °C). The 40 specimens were distributed among four experimental groups (n = 10): L-C- (control), L + C- (LED for 5 min), L-C+ (curcumin for 5 min), and L + C+ (PDT). Aliquots of 100 μL were collected from the bone cavities after treatments and were seeded in duplicate on Sabouraud dextrose agar for 24 h at 36 °C ± 1 °C and the colony-forming units (CFU/ mL) were counted. Before and after each treatment, the specimens were subjected to spectral fluorescence and the images were compared using the Image J program. The log₁₀ CFU/mL were compared with Kruskal-Wallis and Dunn's Multiple Comparison post-test (significance level at 0.05). The fluorescence histogram values before and after treatment were compared using Wilcoxon test (95%).The correlation between Candida albicans log₁₀ CFU/mL and the number of the fluorescence red pixels spectroscopy was verified using Spearman correlation test. The reduction of Candida albicans log₁₀ CFU/mL in the L + C+ (PDT) group was the most relevant and the fluorescence spectroscopy was correlated to the microbiological result. It was concluded that there was a consistency between the number of Candida albicans log₁₀ CFU/mL and the red pixel data of the fluorescence images, demonstrating that the fluorescence diagnostic device reflects the true microbiological condition of Candida albicans biofilms in the bone cavities during the pre-treatment and post-treatment, thus providing the clinician the ability to dynamically, simply, and instantaneously verify the performance of the treatment used.

Photodynamic inactivation of Candida ssp. on denture stomatitis. A clinical trial involving palatal mucosa and prosthesis disinfection

Denture stomatitis (DS) is the most common oral fungal infection in denture wearers. Photodynamic inactivation (PDI) has been showing to be an effective technique in vivo against fungi, including fungal infections in the oral cavity. The disinfection of both oral mucosa and denture may represent a real advantage in terms of fungus control. This clinical study was designed to explore methylene blue (MB)-mediated PDI on oral mucosa and prosthesis of patients with DS. Subjects with DS were divided into two groups. One group received treatment based on the use of oral miconazole gel 2% (MIC). The other group received treatment by PDI using MB at 450 μg/mL and a diode laser (λ = 660 nm) with 100 mW and fluence of 28 J/cm². Clinical outcome was evaluated regarding the degree of oral mucosa erythema and microbiological reduction of Candida spp. located in both palatal mucosa and prosthesis. Our results showed that PDI was significantly more effective than MIC in ameliorating inflammation after 15 days. Following 30 days, no statistically significant differences were observed between groups. Regarding the fungal burden, although the MIC group has presented more pronounced inactivation than PDI for both mucosa and prosthesis, no statistically significant differences were detected between them. This clinical study suggests that PDI can reduce fungal load and decrease the inflammation degree in patients with Candida-associated denture stomatitis.

Photoinactivation of single and mixed biofilms of Candida albicans and non-albicans Candida species using Photodythazine® [corrected]

This study evaluated the effectiveness of antimicrobial photodynamic therapy (aPDT) mediated by Photodithazine^® (PDZ) formulated in hydrogel, in the inactivation of mono and duo-species biofilms of Candida albicans, Candida glabrata and Candida tropicalis. Standardized suspensions of each strain were prepared and after biofilm formation, mono-species were treated with 150 and 175mg/L of PDZ for 20min (pre-irradiation time), and exposed to LED light at a dose of 37.5J/cm² (660nm). The duo-species biofilms (C. albicans+C. glabrata and C. albicans+C. tropicalis) were treated with 150mg/L of PDZ and light. Additional samples were treated with PDZ or light only, and the control did not receive any treatment. Next, microbiological evaluation was performed by spreading the cells on Sabouraud Dextrose Agar and CHROMagar Candida for colony forming units (CFU/mL). Moreover, the total biomass of biofilm was verified using the crystal violet staining assay (CV). The data were submitted to ANOVA and Tukey post-hoc (α=0.05). The use of PDZ 150mg/L promoted a reduction of 1.0, 1.2, 1.5 log₁₀ in the viability of C. glabrata, C. albicans and C. tropicalis, respectively. The same concentration reduced in 1.0 log₁₀ the viability of each species grown as duo-species biofilms. The crystal violet assay showed that the use of 150mg/L reduced 24.4%, 39.2% and 43.7% of the total biomass of C. albicans, C. tropicalis and C. glabrata, respectively. aPDT did not reduce the total biomass to the duo-species biofilms. Thus, PDZ-mediated aPDT was more effective in the inactivation of mono-species biofilms of Candida spp. compared with duo-species biofilm.

Clinical Comparison of Two Photosensitizers for Oral Cavity Decontamination

OBJECTIVE

In this study, we aim to compare the photodynamic inactivation (PDI) effects of two different photosensitizers (PS), Photogem^® and Natural Curcumin, irradiated with light-emitted diodes (LED) at 630 and 450 nm, respectively.

BACKGROUND

The current antimicrobial mouthwash for oral hygiene has several drawbacks. In this context, PDI is an alternative technique to inactivate pathogenic microbes in mucosa and in periodontal tissue. Furthermore, there are numerous infectious diseases that may affect the oral cavity, motivating the use of PDI in dentistry.

METHODS

The volunteers (n = 50) were randomize separated into five experimental groups (n = 5) for each PS: water control, PS control, light control, and two PS concentrations (25 and 100 mg/L). Each patient underwent mouthwash solution containing the PS before illumination procedure that was performed with an LED device. For microbial decontamination evaluation, the saliva was collected three times: before (T0), immediately after (T1), and 24 h after the illumination procedure (T2). After that, the difference between the colony forming units (CFU) for each volunteer was compared.

RESULTS

The results show that regardless of PS and treatment applied, there was microbial reduction immediately after PDI, however, after 24 h only Natural Curcumin still presents a reduction. For Photogem after 24 h, the microorganism returns to the original CFU.

CONCLUSIONS

Immediately after PDI, both PS have the same efficiency, nevertheless the Natural Curcumin still has an efficacy after 24 h and also is a more viable photosensitizer. In addition, the results indicate that PDI can be a promised technique used for microbial reducing for the oral cavity.

Photodynamic inactivation of a multispecies biofilm using curcumin and LED light

This study evaluated the potential of curcumin-mediated antimicrobial photodynamic inactivation (API) on multispecies biofilms of Candida albicans, Candida glabrata, and Streptococcus mutans of different ages. Acrylic samples (n = 480) were made with standardized rough surfaces and incubated with bacteria and yeast for 24 or 48 h. API was performed with curcumin (80, 100, 120 μM) and LED light. Additional acrylic samples were treated with curcumin or LED light only. Positive control samples received neither light nor curcumin. After API, colony counts were quantified (CFU/mL), cell metabolism was determined by means of XTT assay, and the total biofilm biomass was evaluated using Crystal Violet (CV) staining assay and images were obtained by confocal laser scanning microscopy (CLSM). The data were analyzed by nonparametric two-way ANOVA and post hoc Tukey tests (α < 0.05). For 24-h biofilm, API resulted in statistically significant difference (ρ < 0.001) of viability of C. albicans compared with control (P-L-) for all Cur concentrations. For 48-h biofilm, API resulted in statistically significant difference (ρ < 0.001) compared with control only when Cur at 120 μM was used. API promoted statistically significant difference (ρ ≤ 0.001) in the viability of S. mutans and C. glabrata for all Cur concentrations in the two biofilm ages. In addition, API produced a statistically significant difference (ρ < 0.001) of metabolic activity and of total biomass (ρ < 0.001) of multispecies biofilms compared with control for all Cur concentrations. It can be concluded that both 24- and 48-h biofilms were susceptible to API mediated by Cur; however, 24-h biofilm was more sensitive than the 48-h biofilm.

An In Vitro Comparison of Antimicrobial Effects of Curcumin-Based Photodynamic Therapy and Chlorhexidine, on Aggregatibacter actinomycetemcomitans

INTRODUCTION

Considering the importance of prevention in periodontal diseases and the important role of Aggregatibacter actinomycetemcomitans in induction and progression of these diseases, the aim of the present in vitro study was to compare the antimicrobial effects of chlorhexidine digluconate (CHX), curcumin and light-emitting diode (LED) laser, on this bacterium.

METHODS

Antimicrobial activity of curcumin (5 mg/ml), CHX (2%), LED (120 J/cm(2)) and LED + curcumin (120 J/cm(2) + 2.5 mg/ml) against A. actinomycetemcomitans were tested in vitro, using micro-broth dilution test. One-way analysis of variance (ANOVA) and Tukey's HSD tests served for statistical analysis.

RESULTS

Regarding the minimum inhibitory concentration (MIC), CHX had a significantly lower MIC than curcumin (P < 0.05). Sorted out by bacterial growth from lowest to highest, were CHX, LED + curcumin, curcumin, and LED groups. All the differences were found to be statistically significant (P < 0.05) except for the LED group.

CONCLUSION

We conclude that curcumin is an effective substance in preventing the growth of A. actinomycetemcomitans, whose impact is reinforced when used simultaneously with photodynamic therapy (PDT).

Use of Photosensitizers in Semisolid Formulations for Microbial Photodynamic Inactivation

Semisolid formulations, such as gels, creams and ointments, have recently contributed to the progression of photodynamic therapy (PDT) and microbial photodynamic inactivation (PDI) in clinical applications. The most important challenges facing this field are the physicochemical properties of photosensitizers (PSs), optimal drug release profiles, and the photosensitivity of surrounding tissues. By further integration of nanotechnology with semisolid formulations, very promising pharmaceuticals have been generated against several dermatological diseases (PDT) and (antibiotic-resistant) pathogenic microorganisms (PDI). This review focuses on the different PSs and their associated semisolid formulations currently found in both the market and clinical trials that are used in PDT/PDI. Special emphasis is placed on the advantages that the semisolid formulations bring to drug delivery in PDI. Lastly, some potential considerations for improvement in this field are also discussed.

Methylene Blue-Mediated Photodynamic Inactivation Followed by Low-Laser Therapy versus Miconazole Gel in the Treatment of Denture Stomatitis

PURPOSE

Photodynamic therapy (PDT) appears to be an effective method for the in vitro and in vivo inactivation of Candida spp., but no clinical trials in this context have yet been conducted. The aim of this study was to compare the effect of oral miconazole gel to PDT combined with low-power laser (LPL) therapy in the treatment of denture stomatitis.

MATERIALS AND METHODS

Forty participants with clinical and microbiological diagnoses of type II denture stomatitis were randomly allocated to two treatment groups (PDT and miconazole gel), each with 20 individuals. The PDT group was submitted to one session of methylene blue-mediated PDT plus two sessions of low-laser therapy twice a week for 15 days. The miconazole group was submitted to the drug four times a day for 15 days.

RESULTS

Forty percent of the patients achieved clinical and microbiological resolution of denture stomatitis after methylene blue-mediated photodynamic inactivation followed by low-laser therapy. The cure rate associated with miconazole was 80% (p < 0.05). Fifteen days after the end of treatment, the recurrence rate was 25% in patients treated with PDT combined with LPL therapy and 12.5% in patients treated with miconazole.

CONCLUSION

Miconazole gel provides better results than a protocol combining methylene blue-mediated PDT and LPL therapy in the treatment of type II denture stomatitis.

Identificação das espécies de Candida em portadores de estomatite protética e avaliação da susceptibilidade ao miconazol e à terapia fotodinâmica

INTRODUÇÃO: Próteses mucossuportadas são consideradas facilitadoras, em potencial, da estomatite protética (EP), condição caracterizada pelo aspecto eritematoso, difuso ou pontilhado da mucosa palatina sob a base das próteses. A etiologia da doença é multifatorial, embora a infecção por Candida seja uma causa bastante comum. OBJETIVO: Relacionar a EP com a presença de Candida, identificar as espécies de Candida mais prevalentes, a partir do meio CHROMagar Candida(r), e caracterizar o perfil de sensibilidade das colônias ao miconazol e à terapia fotodinâmica (TFD). MATERIAL E MÉTODO: A amostra foi constituída por 45 usuários de prótese total, sendo 30 com diagnóstico clínico de EP e 15 sem a doença. Realizou-se raspagem com swab da mucosa palatina e das próteses, e as amostras foram semeadas em CHROMagar Candida(r), para identificação de espécies de C. albicans, C. krusei e C. tropicalis. Após incubação e leitura das placas, as colônias foram reisoladas em Ágar Sabouraud, para caracterização da sensibilidade ao miconazol e à TFD. RESULTADO: Espécies de Candida estiveram presentes em 53,33% das amostras dos pacientes com EP e em 6,67% das amostras dos pacientes sem EP, considerando-se o total de amostras de mucosa (p=0,008) e próteses (p=0,001). As espécies mais prevalentes foram C. albicans (36,67% e 53,33%), seguida de C. tropicalis (13,33% e 16,67%) e C. krusei (13,33% e 6,67%), em mucosa e prótese, respectivamente. As amostras mostraram maior sensibilidade ao miconazol que à TFD (p<0,0001). CONCLUSÃO: Existiu uma associação entre a presença de Candida e EP, sendo C. albicans a espécie mais prevalente. Miconazol proveu melhores resultados na eliminação in vitro de colônias de Candida quando comparado à TFD.

Inactivation of Aggregatibacter actinomycetemcomitans by two different modalities of photodynamic therapy using Toluidine blue O or Radachlorin as photosensitizers: an in vitro study

Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) is one of the periodontopathogens strongly associated with aggressive periodontitis. The aim of this investigation was to compare the effect of laser and light-emitting diode on the photodynamic inactivation of A. actinomycetemcomitans. Eighty-four samples of bacterial suspensions (200 μL) were prepared and divided in seven groups: control group (no treatment), laser group (indium-gallium-aluminum-phosphate laser with wavelength of 662 ± 0.1 nm, energy density of 6 j/cm(2), and irradiation time of 34 s), light-emitting diode (LED) group (wavelength 625-635 nm, energy density 6 j/cm(2), time of irradiation 30 s), Toluidine blue O (TBO) group (0.1 mg/mL), Radachlorin group (0.1 %), Radachlorin + laser group (after pre-irradiation time of 10 min, laser was irradiated), and TBO + LED group (after preirradiation time of 10 min, LED was irradiated). Then, 100 μL of each sample was cultured in brain heart infusion (BHI) plates and incubated for 48-72 h in microaerophilic atmosphere for colony counting. Application of Radachlorin + laser resulted in a significant decrease in the concentration of A. actinomycetemcomitans (P values <0.05). Photodynamic therapy with laser + Radachlorin was more effective than that of LED + TBO in suppression of this microorganism (P value <0.05). Within the limits of this study, it can be concluded that photodynamic inactivation using laser and Radachlorin was more effective than that of LED and TBO in eradication of A. actinomycetemcomitans.

Photodynamic inactivation of clinical isolates of Candida using Photodithazine®

This study evaluated the photodynamic inactivation (PDI) mediated by Photodithazine(®) (PDZ) against 15 clinical isolates of Candida albicans, Candida glabrata and Candida tropicalis. Each isolate, in planktonic and biofilm form, was exposed to PDI by assessing a range of PDZ concentrations and light emitting diode fluences. Cell survival of the planktonic suspensions was determined by colony forming units (CFU ml(-1)). The antifungal effects of PDI against biofilms were evaluated by CFU ml(-1) and metabolic assay. Data were analyzed by non-parametric tests (α = 0.05). Regardless of the species, PDI promoted a significant viability reduction of planktonic yeasts. The highest reduction in cell viability of the biofilms was equivalent to 0.9 log10 (CFU ml(-1)) for C. albicans, while 1.4 and 1.5 log10 reductions were obtained for C. tropicalis and C. glabrata, respectively. PDI reduced the metabolic activity of biofilms by 62.1, 76.0, and 76.9% for C. albicans, C. tropicalis, and C. glabrata, respectively. PDZ-mediated PDI promoted significant reduction in the viability of Candida isolates.

Comparative antifungal efficacy of light-activated disinfection and octenidine hydrochloride with contemporary endodontic irrigants

The aim of this study was to evaluate the antifungal effects of light-activated disinfection (LAD) in comparison with contemporary root canal irrigation solutions: sodium hypochlorite and 2% chlorhexidine gluconate and a new wound antiseptic, octenidine hydrochloride. Seventy extracted teeth having single root canals were contaminated with Candida albicans for 14 days. The samples were divided into five experimental (n = 10) and two control (positive and negative) groups (n = 10): (1) LAD with toluidine blue O, (2) octenidine hydrochloride (OCT), (3) 2.5% sodium hypochlorite (2.5% NaOCl), (4) 5.25% sodium hypochlorite (5.25% NaOCl) and (5) 2% chlorhexidine. Five millilitres of each test solution was applied for 3 min, and irradiation time used for LAD was 30 s. After treatment, the dentin chips were collected from inner canal walls into vials containing phosphate buffered saline, vortexed, serially diluted, seeded on Tryptic Soy Agar plates and incubated (37 °C, 48 h). The number of colony-forming units was then counted. Differences between LAD group and positive control group were statistically significant (P < 0.05). All Candida cells were totally eliminated in root canals irrigated with OCT, 2.5% NaOCl, 5.25% NaOCl and 2% chlorhexidine groups (CFU = 0). Within the limitations of this ex vivo study, LAD had minimal antimicrobial effect on C. albicans when used 30 s, and further modifications in LAD protocol are required to improve its antifungal capability. A new wound antiseptic, octenidine hydrochloride, demonstrated better potential than LAD in elimination of Candida albicans cells and may be a promising alternative to NaOCl and chlorhexidine solutions in future.

Methods for obtaining reliable and reproducible results in studies of Candida biofilms formed in vitro

Biofilm formation is one of the most important attributes for virulence in Candida species and contributes to increased resistance to antifungal drugs and host immune mechanisms. These features have led to the development of several methodologies to reproduce a sessile community in vitro that can be used to study the development of a biofilm, its interaction with other microorganisms and the environment, and its susceptibility to available antifungal agents and also to search for new therapy strategies. The purpose of this review is to describe the most commonly used methods to study Candida biofilms in vitro, to discuss the benefits and limitations of the different methods to induce biofilm formation, and to analyse the architecture, viability and growth kinetics of Candida biofilms.