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

Reduction of Multispecies Biofilms on an Acrylic Denture Base Model by Antimicrobial Photodynamic Therapy Mediated by Natural Photosensitizers

OBJECTIVES

The aim of this study is to investigate the antimicrobial efficacy of antimicrobial photodynamic therapy (PDT) using natural photosensitizers (curcumin, riboflavin, and phycocyanin) and light-emitting diode (LED) irradiation against multispecies biofilms in an acrylic denture base model.

MATERIALS AND METHODS

Forty-five acrylic specimens were fabricated using heat-curing acrylic resin. The specimens were then infected with a mixed culture of bacterial and fungal species (including Streptococcus mutans, Streptococcus sanguinis, Candida albicans, and Candida glabrata) for 4 days. The acrylic discs were divided into nine groups, with each group containing five discs: control, 0.2% chlorhexidine, 5.25% sodium hypochlorite, curcumin, riboflavin, phycocyanin alone or along with LED. After treatment, the number of colony-forming units (CFUs) per milliliter was counted. In addition, the extent of biofilm degradation was assessed using the crystal violet staining method and scanning electron microscopy.

RESULTS

All experimental groups exhibited a significant reduction in colony numbers for both bacterial and fungal species compared to the control (p < 0.001). The PDT groups exhibited a statistically significant reduction in colony counts for both bacteria and fungi compared to the photosensitizer-only groups.

CONCLUSIONS

The results of this in vitro study show that PDT with natural photosensitizers and LED devices can effectively reduce the viability and eradicate the biofilm of microorganisms responsible for causing denture infections.

Efficacy of methylene blue-mediated antimicrobial photodynamic therapy on clinical and radiographic outcomes among patients with periodontal diseases: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

This study aimed to assess the influence of methylene blue (MB)-mediated adjunctive antimicrobial photodynamic therapy (aPDT) when compared to conventional mechanical debridement (MD) alone on periodontal clinical and radiographic outcomes among periodontitis patients.

METHODS

Randomized clinical trials (RCTs) were incorporated by conducting an electronic search in Web of Science, Scopus, and PubMed for articles published in English up to August 2023 to address the following focused question based on the PICO format: "Whether the application of MB-mediated aPDT as an adjunctive to MD (Intervention) leads to improved periodontal clinical and/or radiographic outcomes (Outcome) among participants with and without periodontal diseases (Population) as compared to MD alone (Conparison)". The risk of bias (RoB) of the included studies was assessed using the modified Jadad scale. A meta-analysis was conducted, and it included the presentation of the standard mean difference (SMD) along with a 95 % confidence interval (CI).

RESULTS

In total, 11 studies were included in this systematic review and meta-analysis. The meta-analysis demonstrated statistically significant improvements in periodontal plaque index (SMD: -0.72 % [95 % CI: -0.99 % to -0.45 %]; p<0.00001), probing depth (SMD: -0.38 % [95 % CI: -0.57 % to -0.19 %; p<0.00001), and bleeding on probing (SMD: -0.44 % [95 % CI: -0.68 % to -0.20 %]; p = 0.0003) scores at the final follow-up visit after the application of MB-mediated aPDT in comparison with MD alone. Nevertheless, there was no statistically significant difference was observed in periodontal clinical attachment level values (SMD: -0.01 % [95 % CI: -0.21 % to 0.19 %]; p = 0.95) between the control group and the experimental group. Six studies achieved a low RoB, five were rated as having medium RoB, while no study received a high RoB.

CONCLUSION

MB-mediated aPDT, when used as an adjunct to conventional MD contributes to the improvement of periodontal clinical outcomes including PI, PD, and BOP in patients with periodontitis.

Adhesive Bond Strength of Restorative Materials to Caries-Affected Dentin Treated with Antimicrobial Photodynamic Therapy: A Systematic Review and Meta-Analysis

Objective: This systematic review aimed to evaluate the adhesive bond strength of restorative materials to caries-affected dentin (CAD) treated with antimicrobial photodynamic therapy (aPDT) in comparison with conventional chemical disinfectants. Methods: Three databases, including the Web of Science, Scopus, and PubMed, were searched to address the focused question: "What is the effect of aPDT compared to conventional chemical disinfection techniques on the adhesive bond strength of restorative materials to CAD?." Search keywords included "dentin*" "adhes bond*" "caries-affected dentin" "photodynamic "photochemotherapy" "photosensitizing agent" "phototherapy" "photoradiation" "laser" "light activated" "photoactivated." A fixed-effects model was used in each meta-analysis and the inverse variance was used to calculate the standard mean difference (SMD). For evaluating the statistical heterogeneity, the Cochrane's Q test and the I2 statistics were used. The risk of bias was evaluated based on the Cochrane Collaboration's tool. Results: Fourteen studies were included in the qualitative as well as quantitative analysis. The results of the meta-analyses exhibited an SMD of 2.38% [95% confidence interval (CI): 2.03-2.73; p < 0.00001], indicating a statistically significant difference in the shear bond strength scores between the tested group (samples treated with aPDT) and the control group (i.e., favoring the sound dentin and/or conventional chemical disinfectants). Contrarily, an SMD of -1.46% (95% CI: -2.04 to -0.88; p < 0.00001) and -0.37% (95% CI: -0.70 to -0.03; p = 0.03) was observed, indicating a statistically significant difference in the microtensile bond strength (μTBS), as well as microleakage scores between the tested group (favoring the samples treated with aPDT) and the control group (i.e., sound dentin and/or conventional chemical disinfectants). Conclusions: Adhesive bond strength of restorative materials to CAD treated with conventional chemical disinfectants showed superior outcomes compared to photodynamic therapy (aPDT).

In vitro comparison of antifungal activity of conventional alcohol sprays and antimicrobial photodynamic therapy on acrylic denture resin

BACKGROUND

Traditionally, alcohol sprays are used for disinfection of acrylic-base denture surfaces. A limited number of studies have assessed the role of antimicrobial photodynamic therapy (aPDT) in this regard; however, it remains debatable whether conventional alcohol sprays are superior to aPDT in terms of antifungal activity or vis versa.

OBJECTIVE

The aim of the present in vitro study is to compare the antifungal activity of conventional alcohol sprays and aPDT on acrylic denture resin.

METHODS

Individuals wearing complete dentures at least on one arch were included. Dentures were randomly divided into three groups. Groups 1-3 were disinfected with an alcohol-based antiseptic spray and aPDT, respectively. Assessment of oral yeast growth was done using swab samples. The culture mediums were incubated at 37∘C for 72 hours and viewed through a microscope. The numbers of colony forming units (CFU/ml) were determined. P< 0.05 were considered statistically significant.

RESULTS

At baseline, the mean CFU/ml in Groups 1-3 were comparable. After disinfection, a statistically significant reduction in microbial CFU/ml was observed in Groups 1 (P< 0.05) and 2 (P< 0.05) compared with baseline. In Group 3, there was no difference in CFU/ml throughout the study. After disinfection, there was no difference in microbial CFU/ml in dentures in Groups 1 and 2.

CONCLUSION

Conventional alcohol sprays are as effective as aPDT towards reducing oral yeasts CFU/ml on acrylic denture resin.

The efficacy of antimicrobial photodynamic therapy in the disinfection of coronal and radicular dentine of primary teeth: A systematic review and meta-analysis

BACKGROUND

Optimal endodontic disinfection by means of conventional root canal treatment of primary teeth remains a challenge. Recently, antimicrobial photodynamic therapy (aPDT) has been proposed as an adjunct to conventional endodontic treatment for microbial disinfection. The purpose of this review is to critically appraise and synthesize the currently-available evidence about the antimicrobial efficacy of aPDT (antimicrobial photodynamic therapy) when used as an adjunct to traditional root canal therapy.

MATERIALS AND METHODS

The focused question was ''In primary teeth needing root canal treatment (participants), is adjunct aPDT (intervention) more effective in disinfecting coronal and radicular dentine (outcomes) than root canal treatment alone (control)?'. The electronic research databases PubMED/Medline, ISI Web of Knowledge, Embase and CENTRAL (Cochrane Central Register of Controlled Trials) using relevant keyword phrases including 'antimicrobial photodynamic therapy', 'primary teeth', 'deciduous teeth', and 'endodontic treatment'. Original studies that described endodontic treatment of primary teeth or dentine using aPDT in comparison to conventional endodontic treatment were included. Case reports, reviews and other non-comparative studies were excluded. The literature search and quality assessment were carried out by two reviewers independently.

RESULTS

Ultimately, 9 studies were included in this review. Overall, majority of the studies concluded that adjunct aPDT improves the antimicrobial efficacy of conventional root canal therapy. However, several sources of bias were found in the studies.

CONCLUSION

Within the limitations of the studies, it is concluded that aPDT is a suitable adjunct to improve the disinfection of conventional root canal treatment. However, future studies should focus on the clinical outcomes, in relation to the reduction of microbial counts to ascertain the efficacy of aPDT in disinfection of primary dentine.

Knowledge and application of antimicrobial photodynamic therapy among restorative dentist in Saudi Arabia

BACKGROUND

The aim was to identify the restorative dentist, knowledge and application of Antimicrobial photodynamic therapy (aPDT) in dental practice; and to provide an overview of the potential challenges faced by restorative dentists (RD) in Saudi Arabia.

METHODS

A 15-item cross sectional study questionnaire was distributed through online portal to assess the knowledge, and practice of RD towards aPDT and its practice. The questionnaire consisted of 3 sections, exploring the demographics of participants, knowledge, application and perception of aPDT using yes/no response and Likert scale. Response means, frequencies, and chi-square tests to compare subgroups based on gender, education level, and practice experience.

RESULTS

Out of 500 participants, 375 completed the survey forms (75% response rate). The majority was male (68%) with a mean age of 46 years. Respondents demonstrated a moderate level of knowledge (60.5%). Only 33% expressed confidence in aPDT as a standalone treatment, while 67% showed limited referrals to specialists. However, 88.5% expressed interest in receiving training and attending workshops for aPDT therapy. Education and experience significantly influenced overall knowledge question responses (p = 0.031).

CONCLUSION

Majority of restorative dentists demonstrated a moderate understanding of the role of aPDT in dentistry. More than two thirds of respondents (77%) believed that aPDT is an effective adjuvant therapy. Increased experience (> 10 years) and education (Post-graduates) showed higher application of aPDT. The study reveals the potential for incorporating aPDT knowledge into restorative dental practices, particularly among general dentists.

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.

Influence of Contemporary Photoactivated Disinfection on the Mechanical Properties and Antimicrobial Activity of PMMA Denture Base: A Systematic Review and Meta Analysis

PURPOSE

The present study aimed to perform a systematic review and meta-analysis to investigate the effectiveness of the contemporary photoactivated disinfection methods on the mechanical features and/or antimicrobial activity of polymethyl methacrylate (PMMA) dentures bases.

METHODS

THE FOCUSED RESEARCH QUESTION WAS: : "What is the effect of contemporary photoactivated disinfection methods as compared to conventional disinfection protocols on the mechanical features and/or antimicrobial activity of PMMA dentures bases?". An electronic literature search was carried out by the author and a senior librarian specialized in health sciences on Web of Science, PubMed, and Scopus. In vitro investigations evaluating the antimicrobial and/or mechanical effects of photoactivated disinfectants as compared to conventional chemical disinfectants on the microbes formed on PMMA denture bases were included. Meta-analysis was performed for calculating the standard mean difference (SMD) with a 95% confidence interval.

RESULTS

Four out of eight studies concluded that photoactivated disinfectants, including riboflavin-mediated photodynamic therapy (PDT), hematoporphyrin-mediated PDT, poly-L-glycolic acid loaded with methylene blue, Erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser, erbium-doped yttrium-aluminum-garnet (Er:YAG) laser, and chitosan-mediated PDT, demonstrated a significant reduction in colony-forming unit per milliliter (CFU/mL) of exposed viable colonies of Escherichia coli (E. coli), Streptococcus mutans (S. mutans), Staphylococcus aureus (S. aureus), and Candida albicans (C. albicans) comparable to the conventionally used chemical disinfectants of PMMA denture bases. Contrarily, two studies concluded that the PMMA denture base colonized with C. albicans and disinfected with conventional chemical disinfectants showed the greatest anti-fungal efficaciousness. All the included studies concluded that the application of photoactivated disinfectants does not negatively impact the mechanical features of the PMMA denture bases colonized with microbes including E. coli, S. mutans, S. aureus, and C. albicans. The meta-analysis revealed statistically significant reduction in C. albicans counts (CFU/mL [Log10]) (p < 0.00001) and improvement in the flexural strength (p = 0.0002) of PMMA-based denture base after the application of conventional disinfectants, while a statistically significant improvement in the fracture strength of PMMA-based denture base was observed after the application of photoactivated disinfectants (p = 0.03).

CONCLUSION

According to the systematic review (qualitative synthesis), photoactivated disinfectants demonstrated comparable mechanical features and antimicrobial activity of PMMA dentures bases to conventional chemical disinfectants suggesting their potential to be utilized as an alternative to conventional chemical disinfectants. However, the meta-analysis (quantitative synthesis) revealed that the application of conventional disinfectants demonstrated better outcomes related to antimicrobial activity and flexural strength of PMMA-based denture based.

The role of the light source in antimicrobial photodynamic therapy

Antimicrobial photodynamic therapy (APDT) is a promising approach to fight the growing problem of antimicrobial resistance that threatens health care, food security and agriculture. APDT uses light to excite a light-activated chemical (photosensitiser), leading to the generation of reactive oxygen species (ROS). Many APDT studies confirm its efficacy in vitro and in vivo against bacteria, fungi, viruses and parasites. However, the development of the field is focused on exploring potential targets and developing new photosensitisers. The role of light, a crucial element for ROS production, has been neglected. What are the main parameters essential for effective photosensitiser activation? Does an optimal light radiant exposure exist? And finally, which light source is best? Many reports have described the promising antibacterial effects of APDT in vitro, however, its application in vivo, especially in clinical settings remains very limited. The restricted availability may partially be due to a lack of standard conditions or protocols, arising from the diversity of selected photosensitising agents (PS), variable testing conditions including light sources used for PS activation and methods of measuring anti-bacterial activity and their effectiveness in treating bacterial infections. We thus sought to systematically review and examine the evidence from existing studies on APDT associated with the light source used. We show how the reduction of pathogens depends on the light source applied, radiant exposure and irradiance of light used, and type of pathogen, and so critically appraise the current state of development of APDT and areas to be addressed in future studies. We anticipate that further standardisation of the experimental conditions will help the field advance, and suggest key optical and biological parameters that should be reported in all APDT studies. More in vivo and clinical studies are needed and are expected to be facilitated by advances in light sources, leading to APDT becoming a sustainable, alternative therapeutic option for bacterial and other microbial infections in the future.

Efficacy of curcumin-mediated photodynamic therapy for root canal therapy procedures: A systematic review

BACKGROUND

This systematic review aimed to investigate the effectiveness of CUR-mediated PDT (Curcumin mediated PDT) as an adjunct to conventional chemo-mechanical debridement and/or standard PDT of the RC system with endodontic infections.

METHODS

The focused research question was: "Whether the application Curcumin mediated PDT as an adjunct is more effective than the traditional chemo-mechanical debridement and/or standard PDT of the RC system alone for improving antibacterial and/or mechanical features among subjects undergoing RCT?". An electronic literature search was performed in Scopus, PubMed, and Web of Science. In vitro reports utilizing Curcumin mediated PDT as an adjunct to conventional chemo-mechanical debridement considering permanent dentition assessing the antibacterial and/or mechanical effect were included.

RESULTS

Eighteen articles were included in the review, out of which 13 studies assessed the antibacterial activity, while 5 evaluated the mechanical properties. Most of the studies concluded that Curcumin mediated PDT had a significant antibacterial activity than the conventional chemo-mechanical debridement and/or standard PDT. Four of the five studies suggested that Curcumin mediated PDT had no impact on the push-out bond strength of root dentin. Furthermore, the significant heterogeneity in the data from the included studies did not permit the author to carry out a meta-analysis.

CONCLUSION

There is potential for application of Curcumin mediated PDT as an adjunct to the conventional chemo-mechanical debridement and/or standard PDT in reducing the bacterial load, however, Curcumin mediated PDT has minimal effect on enhancing the pushout bond strength of fiber posts to radicular dentin. Moreover, clinical studies are required to provide a more conclusive opinion on the efficacy of Curcumin mediated PDT for RCT procedures.

Fracture strength of Er,Yag laser treated PMMA denture-based polymer (DBP) colonized with C. albicans, S. aureus, S.mutans, and E.coli

AIM

To assess and equate the efficacy of different disinfection protocols autoclave, chlorhexidine (CHX), PDT utilizing Rose Bengal (RB), chitosan, and Er, Yag laser and their effect on fracture strength of PMMA denture-based polymer (DBP) colonized with C. Albicans, S. aureus, S.mutans, and E.coli.

MATERIAL AND METHODS

A total of 50 (n = 10) PMMA DBP were manufactured and adulterated with the American Type Culture Collection (ATCC) of diverse microbial colonies inhabited by C. Albicans, S. aureus, S.mutans, and E.coli. The specimens were subjected to different denture disinfection approaches by randomly distributing in into five groups i.e., Er, Yag laser, RB, autoclave, CHX, and Chitosan, respectively for appraising antimicrobial effectiveness. PMMA fracture load was also assessed and statistical analysis was performed for CFU/mL (log10) of exposed C. Albicans, S. aureus, S.mutans, and E.coli by one-way ANOVA and Tukey's multiple comparison test at a significance level of p < 0.05.

RESULTS

Intergroup comparison disclosed that denture disinfection with Er, Yag laser, autoclave, Chitosan, and CHX (control) validated comparable antimicrobial efficacy to denture against all inspected CFU/mL (log10) (p>0.05). The intragroup comparison revealed that DBP sanitization with Er, Yag laser, autoclave, Chitosan, RB, and CHX substantiated equivalent effective antimicrobial efficacy in plummeting CFU/mL (log10) of S. mutans and E. coli (p>0.05) but in consideration to S.aureus and C.albicans, all groups resulted in declining their count except 5µm RB activated by PDT(p < 0.05). No significant difference was perceived in fracture load of PMMA denture base among Er, Yag laser, RB, chitosan, and CHX (control) (p > 0.05) except autoclave decontamination procedure that indicated the least fracture strength of DBP when disinfected (p < 0.05).

CONCLUSION

Er, Yag laser, and Chitosan activated by PDT have the potential to be used as an alternative to chlorhexidine for disinfecting Polymethyl methacrylate denture base as they demonstrated the highest antimicrobial efficacy against E. coli, C. Albicans, S aureus, and S. mutans with optimal fracture load.

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.

Disinfection of caries-affected dentin using activated vitamin B2 and diode laser with total-etch technique. An assessment of adhesive bond

AIM

The present study aims to evaluate the bond integrity of composite restoration bonded to CAD after disinfection using pineapple peel extract (PPE) Diode laser (DL) and riboflavin (RF) activated by photodynamic therapy (PDT).

MATERIAL AND METHODS

Forty human permanent mandibular molars were collected, disinfected, and mounted in poly-vinyl pipes. Carious infected dentin was removed and CAD was disinfected. Samples were divided into 4 groups based on disinfection. Group 1: CAD disinfected with CHX; group 2: CAD disinfected with diode laser; CAD disinfected with PPE and CAD sterilized with riboflavin. Following disinfection, CAD surfaces were applied with the etch-and-rinse adhesive system and bonding agent and restored with a composite restoration. Samples were placed in a thermocycler to simulate oral aging and then mounted on the universal testing machine (UTM) for shear bond strength (SBS) testing. Failure mode was assessed using a steriomicroscoscope at 40X magnification. One-way analysis of variance (ANOVA) compared the mean SBS and failure type obtained to identify intergroup differences. Similarly, for multiple group comparison, the Tukey HSD test was used keeping the level of significance at 0.05 RESULTS: : CAD disinfected with chlorhexidine (CHX) established the highest bond integrity of the restoration. However, group 2 CAD disinfected with DL displayed the lowest bond values. It was also observed that dentin disinfected using CHX demonstrated comparable SBS values to CAD disinfected with PPE and CAD disinfected with RF.

CONCLUSION

RF and PPE displayed comparable outcomes of SBS of composite restoration bonded to CAD to that of CHX. DL displayed lower bond integrity than the other investigated groups. Further studies are recommended to deduce the findings of the existing study.

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.

Use of Photosensitizer, Glutaraldehyde, alcohol and Ultrasonics in disinfection of polished and rough surfaces of self-curing polymethyl methacrylate denture base material

AIM

To assess the effectiveness of chemical, ultrasonic and photodynamic therapy (PDT) mediated disinfection against in-vitro biofilms colonized with C. albicans, S. oralis, and S. aureus on surfaces of PMMA (polymethylmethacrylate) denture base material.

MATERIALS AND METHODS

Fifty plates of PMMA were prepared with two different surface topography (rough and polished) analyzed by profilometry. Provenance culture (ATCC) of C. albicans, S. oralis, and S. aureus were inoculated on specimens and exposed to disinfection. The disinfection included Rosebengal (RB) 5 μM activated by a red LED, 2% glutaraldehyde, 70% Isopropyl alcohol, ultrasonic disinfection, and saline solution as a control. The antimicrobial efficacy was assessed by subsequently calculating viable counts after disinfection. The data were analyzed using analysis of variance (ANOVA) and Tukey's Post Hoc test.

RESULTS

The unpolished surface demonstrated the highest average surface roughness As 5.32±0.36 (μm) and root mean square roughness Rr 7.22±0.81 (μm) compared to the polished surface. Intergroup comparison demonstrated polished and rough PMMA plate disinfected with rose bengal, glutaraldehyde and alcohol-based disinfection exhibited comparable reduction against C. albicans and S. oralis CFU/mL (log10) (p>0.05). Whereas, this reduction was significantly higher on the rough and polished surface of PMMA when disinfected using ultrasounds for 30 sec (p<0.05). Rose Bengal was the most effective method of disinfection against S. aureus both on polished (0.17±0.13) and rough (0.44±0.22) denture plates (p<0.05).

CONCLUSION

The ultrasonic disinfection was most effective in reducing viable microbial counts. RB mediated PDT exhibited a more substantial reduction of the colonies of S.aureus.

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.