Surface decontamination of explanted peri-implantitis-affected implants.

AIM: The present study aimed at evaluating the effect of air-polishing (AP) and a combination of AP and alkaline electrolysed water (AEW) in surface decontamination of explanted peri-implantitis-affected implants. MATERIALS AND METHODS: Twenty-five patients with 34 dental implants scheduled for explantation due to severe peri-implantitis were included. Following implant removal, the apical part of each implant was embedded in acrylic blocks. Implants were randomly allocated to surface decontamination using AP with or without AEW. Four implants were left untreated and used as negative controls. Specimens were analysed using scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). Area of residual bacteria was the primary outcome. RESULTS: SEM analysis revealed that both treatment protocols were effective in biofilm removal and only small proportions of target areas of the implants showed residual bacterial or mineralized deposits. Although differences between the treatment protocols were small, implant thread loci (top/flank/valley), zones of the implant (apical/middle/coronal), implant surface characteristics and gender influenced the results. In addition, EDS analysis showed that zones influenced the atomic% of carbon and calcium and that implant surface characteristics affected the atomic% of titanium. CONCLUSIONS: AP, with or without AEW, is an effective method in removing biofilm from peri-implantitis-affected implants.

Clinical, microbiological and biochemical impact of a supportive care protocol with an air-polishing device, after surgical treatment of peri-implantitis: Randomized clinical trial.

OBJECTIVES: The aim of the present study was to evaluate the efficacy of a supportive peri-implant care (SPIC) protocol after surgical therapy of peri-implantitis, combining ultrasonic mechanical debridement and glycine powder air polishing. MATERIALS AND METHODS: Thirty subjects diagnosed with peri-implantitis and treated by means of access flap were randomized 6 months later into two different SPIC groups: the test group combined a piezoelectric ultrasonic instrumentation with a specific implant PEEK tip and glycine powder air polishing, while control group received the same ultrasonic instrumentation together with a rubber cup and a polishing paste. Patients were followed for 12 months, with intermediate SPIC visits every 3 months. Clinical, radiological, microbiological and biochemical outcome variables were registered and calculated. RESULTS: After 12 months of SPIC, probing depths (PD) showed a mean reduction of 0.33 ± 0.11 mm, with significant differences (p < .001) between the test (-0.84 ± 0.43 mm) and the control group (+0.18 ± 0.73 mm). Healthy peri-implant tissues defined by PD <5 mm, absence of BoP (or in only one site around the implant), and no additional bone loss (<0.5 mm), were observed at the final visit in 83% of the implants (87% in the test group and 80% in the control group, p = .255). No adverse events were reported by the subjects participating in the study. CONCLUSIONS: The SPIC protocol including mechanical ultrasonic debridement and glycine powder air-polishing demonstrated significantly better efficacy in terms of PD reductions. A strict SPIC protocol can maintain for 1 year, or even improve, the results obtained after surgical treatment of peri-implantitis.

The impact of ventilation rate on reducing the microorganisms load in the air and on surfaces in a room-sized chamber.

Hospital-acquired infections (HAIs) are a global challenge incurring mortalities and high treatment costs. The environment plays an important role in transmission due to contaminated air and surfaces. This includes microorganisms' deposition from the air onto surfaces. Quantifying the deposition rate of microorganisms enables understanding surface contamination and can inform strategies to mitigate the infection risk. We developed and validated a novel Automated Multiplate Passive Air Sampling (AMPAS) device. This enables sequences of passive deposition samples to be collected over a controlled time period without human intervention. AMPAS was used with air sampling to measure the effect of ventilation rate and spatial location on the deposition rate of aerosolized Staphylococcus aureus in a 32 m3 chamber. Increasing the ventilation rate from 3 to 6 ACH results in a reduction of microbial load in the air and on surfaces by 45% ± 10% and 44% ± 32%, respectively. The deposition rate onto internal surfaces λd was calculated as 1.38 ± 0.48 h-1 . Samples of airborne and surface microorganisms taken closer to the ventilation supply showed a lower concentration than close to the extract. The findings support the importance of controlling the ventilation and the environmental parameters to mitigate both air and surface infection risks in the hospital environment.

Effects of Er:YAG laser irradiation of different titanium surfaces on osteoblast response.

The aim of this in vitro study was to evaluate the effects of erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation on titanium surface topography and the proliferation and differentiation of osteoblasts using standard clinical treatment settings. Er:YAG laser irradiation at two levels ((1): 160 mJ, pulse at 20 Hz; (2): 80 mJ, pulse at 20 Hz) was applied to moderately rough and smooth titanium disks before MG-63 osteoblast-like cells were cultured on these surfaces. Titanium surface and cell morphology were observed by scanning electron microscopy. Cell proliferation/viability was measured by CCK-8 test. Gene expression of alkaline phosphatase (ALP), osteocalcin (OC), osteoprotegerin (OPG), receptor activator of nuclear factor kappa-B ligand (RANKL), and collagen type 1 was measured by qPCR, and OPG and OC protein production was determined by enzyme-linked immunosorbent assay. Treatment with Er:YAG laser at 160 mJ/20 Hz markedly caused heat-induced fusion of titanium and cell condensation on moderately rough surfaces, but not in smooth surfaces. MG-63 proliferation/viability decreased after 5 days in moderately rough surfaces. The expression of ALP, OC, OPG, and collagen type 1 was unaffected by laser treatment at 160 mJ/20. Laser irradiation at 80 mJ/20 Hz enhanced RANKL gene expression after 5 days in moderately rough surfaces. Study results suggest that Er:YAG laser irradiation at clinically relevant setting has no essential effect on osteogenic gene and protein expression of osteoblasts. However, surface structure, cell attachment, and proliferation are influenced by both treatment protocols, which implies that caution should be taken in the clinical treatment of peri-implant diseases when Er:YAG laser is used.

Clinical outcomes following periodontal surgery and root surface decontamination by erythritol-based air polishing. A randomized, controlled, clinical pilot study.

AIM: To evaluate the outcomes following surgical periodontal treatment and root surface decontamination by means of air polishing using an erythritol powder or conventional mechanical root debridement. MATERIAL AND METHODS: Thirty systemically healthy patients (44.38 ± 8.2 years old, 11 smokers, 19 women) diagnosed with periodontitis stages III-IV were included. Each patient, with one single-rooted tooth, with one probing pocket depth (PD) ≥ 6 mm associated with horizontal bone loss, was treated by means of simplified papilla preservation flap (SPPF) and randomized to either test treatment (careful removal of the calculus with the tip of a blade, air polishing of the root surfaces with erythritol) or to the control group (scaling and root planing with hand curettes, ultrasonic instruments). PD, clinical attachment (CAL), bone sounding (BS), and radiographic bone level (BL) were evaluated at baseline and 12 months postsurgically. RESULTS: Twenty-seven patients completed the 12-month follow-up (test: n = 14, control: n = 13). In both groups, statistically significant improvements were obtained (p < 0.05, mean CAL gain/PD reduction: test, 2.50 ± 1.60 mm/3.00 ± 0.96 mm; control, 2.85 ± 1.21 mm/3.38 ± 1.12 mm). No statistically significant differences were observed between the groups for any of the investigated parameters (p < 0.05). CONCLUSION: Within their limits, the present results indicate that the use of air polishing with an erythritol powder during periodontal surgery may represent a valuable minimally invasive adjunct following calculus removal by means of hand and ultrasonic instruments or a valuable alternative to these, for root surfaces without calculus. CLINICAL RELEVANCE: The use of air polishing with an erythritol powder during periodontal surgery appears to represent a valuable minimally invasive adjunct following calculus removal by means of hand and ultrasonic instruments or a valuable alternative to these, for root surfaces without calculus.

Significance of implant design on the efficacy of different peri-implantitis decontamination protocols.

OBJECTIVE: To assess the efficacy of three mechanical decontamination methods in four types of commercially available implants. MATERIAL AND METHODS: Ninety-six implants of four commercial brands with different designs (regarding thread depth and thread pitch) were soaked in a surrogate biofilm (ink) and air-dried. Circumferential standardized peri-implant defects with 6 mm in depth and 1.55 mm in width were custom-made with a 3D printer. Stained implants were inserted in the defects and instrumented with three different methods: a titanium brush (TNB), a metallic ultrasonic tip (IST) and an air abrasive (PF). Standardized photographs were taken vertically to the implant axis (flat view), and with angulations of 60° (upper view) and 120° (lower view) to the implant long axis. The percentage of residual stain (PRS) was calculated with the image analysis software. Scanning electron microscope evaluations were performed on the buccal aspect of the implants at the central level of the defect. RESULTS: The efficacy of PF was significantly inferior to the TNB and IST in all implant designs, while there were no significant differences between TNB and IST. IST showed significantly higher PRS in the implant with the highest thread pitch, while the TNB had the highest PRS in the implant with a marked reverse buttress-thread design. The micro-thread design had the lowest values of PRS for all decontamination methods. The apically facing threads represented the areas with highest PRS for all implant designs and decontamination methods. CONCLUSION: Thread geometry influenced the access of the decontamination devices and in turn its efficacy. Implants with lower thread pitch and thread depth values appeared to have less residual staining. CLINICAL RELEVANCE: Clinicians must be aware of the importance of thread geometry in the decontamination efficacy.

Opportunities for broadening the application of cell wall lytic enzymes.

In light of emerging antibiotic resistance, bacterial cell wall lytic enzymes are promising antimicrobial agents that degrade bacterial peptidoglycan while specifically recognizing the target bacterium. The efficacy of lytic enzymes against several multi-drug-resistant pathogens infecting humans has led to many efforts focused on in vivo therapeutic applications. However, the potential for lytic enzymes to combat bacterial contamination in environments outside the human body is underexplored. The persistence of pathogenic bacteria, in either planktonic or biofilm states and on various surfaces, has facilitated the spread of bacterial infections, necessitating the development of robust strategies for detecting and killing resistant bacteria in diverse environments. Here, we present an overview of the current state-of-the-art of exploiting lytic enzymes for non-therapeutic applications including pathogen decontamination in social infrastructures and food decontamination, as well as pathogen detection. KEY POINTS: • Lytic enzymes are effective antimicrobial, antibiofilm, and sporicidal agents. • Pathogen detection using lytic enzyme-binding domains is rapid and highly sensitive. • Domain engineering is required for enhanced enzyme activity in complex environments.

Treatment of a peri-implantitis defect using a mini-invasive surgical approach (MISA) and deproteinized bovine bone mineral with 10% collagen: a case series.

This pilot study evaluates the effectiveness of the Mini-Invasive Surgical Approach (MISA) in the treatment of peri-implantitis defect. MISA is based on the use of the deproteinized bovine bone mineral with 10% collagen in combination with a minimal flap. The main principle is the elevation of a flap to access to the peri-implantitis defect only on one side (palatal aspect), leaving the opposite site intact. The study was designed as a non-controlled, non-randomized pilot study. In 10 consecutive subjects, 10 implants with diagnosis of perimplantitis were selected. In all the treated sites, primary closure was obtained at completion of the surgical procedure. No relevant pain, edema and hematoma were noted. The reported surgical approach resulted in significant clinical and radiographic improvements while limiting patient morbidity. After 1-year follow-up minimal mucosal recession, probing depth reduction and radiographic bone gain were noted.

The use of bacteriophage MS2 for the development and application of a virucide decontamination test method for porous and heavily soiled surfaces.

AIMS: (i) To develop an analytical method for recovery and quantification of bacteriophage MS2-as a surrogate for foot-and-mouth disease virus-from complex porous surfaces, with and without the presence of laboratory-developed agricultural grime; (ii) to evaluate, with a 4-log dynamic range, the virucidal activity of common biocides for their ability to decontaminate surfaces and hence remediate facilities, following a foreign animal disease contamination incident. METHODS AND RESULTS: An analytical method was developed and optimized for MS2 recovery from simulated agricultural surfaces. The addition of Dey-Engley neutralizing broth to an extraction buffer improved MS2 viability in liquid extracts, with optimal analytical holding times determined as <8 to ≤24 h, depending on matrix. The recovery of MS2 from surface materials decreased in the order: nonporous reference material >grimed porous materials >nongrimed porous materials. In disinfectant testing, two spray applications of pAB were effective against MS2 (≥4-log reduction) on all operational-scale materials. Two per cent citric acid had limited effectiveness, with a ≥4-log reduction observed on a selected subset of grimed concrete samples. CONCLUSIONS: Decontamination efficacy test results can be affected by surface characteristics, extraction buffer composition, analytical holding time and surface-specific organism survivability. Efficacy should be evaluated using a test method that reflects the environmental characteristics of the intended application. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study demonstrate the importance of analytical method verification tests for disinfectant testing prior to application in complex environments.

The effect of five mechanical instrumentation protocols on implant surface topography and roughness: A scanning electron microscope and confocal laser scanning microscope analysis.

OBJECTIVE: To evaluate in vitro the changes in implant surface topography and roughness of commercial implants after instrumentation with five decontamination protocols. MATERIAL AND METHODS: Seventy-two titanium implants with a sandblasted and acid-etched (SLA) surface were placed 5 mm supra-crestally. Five groups of twelve implants were instrumented with the following protocols: a metal scaler tip (SCAL), a thermoplastic scaler tip (PEEK), a round titanium brush (RBRU), a tufted brush with titanium bristles (TNBRU), and a glycine-based air-powder abrasive (GLYC). A sixth group with untreated implants was used as control. Scanning electron microscope and confocal laser scanning microscope were utilized to evaluate the changes in the implant surfaces. RESULTS: The SCAL caused pronounced macroscopic alterations and damage of the implant surface, the PEEK left remnants of the plastic tip in the implant surface, and both titanium brush groups flattened the thread profile, while minimal alterations were observed in the GLYC. When compared to the control group, the roughness parameters (Sa) in the buccal aspect increased in the thread area of SCAL, and a minor reduction was observed in the PEEK while in the other groups, these values remained unchanged. In the valley areas, however the RBRU, TNBRU, and GLYC experienced a significant reduction (smoothening) indicating different accessibility of the decontamination protocols to the thread and valley. Similarly, the buccal aspects had more pronounced changes than those in the palatal aspect. CONCLUSION: Within the limitations of this in vitro investigation, the tested protocols induced different macroscopic alterations and surface roughness changes that varied in the thread and valley area.

Inactivation of conidia from three Penicillium spp. isolated from fruit juices by conventional and alternative mild preservation technologies and disinfection treatments.

Fungi are able to grow on diverse food products and contribute to food spoilage worldwide causing food loss. Consumers prefer freshly squeezed fruit juices, however, the shelf life of these juices is limited due to outgrowth of yeast and fungi. The shelf life of pulsed electric field (PEF) treated juice can be extended from 8 days up to a few weeks before spoilage by moulds becomes apparent. Conidia produced by three Penicillium ssp. (Penicillium expansum, Penicillium buchwaldii and Penicillium bialowiezense), previously isolated from spoiled PEF treated fruit juice and smoothie, were characterized for resistance towards selected mild physical processing techniques in orange juice and toward sanitizers on surfaces. The results show that Penicillium spp. conidia are susceptible to mild heat, high pressure pasteurization (HPP), PEF, cold atmospheric plasma (CAP), UV, and chemical sanitizers chlorine dioxide and hypochlorite albeit with different susceptibility. Treatment with mild heat, HPP, PEF, or chlorine dioxide reduced conidia by more than 5 log. For hypochlorite, UV, and CAP the reduction was between 1 and 3 log. Together, this study provides data for the development of intervention strategies to eliminate spoilage mould conidia in fruit juices.

Perspectives and Trends in the Application of Photodynamic Inactivation for Microbiological Food Safety.

Photodynamic inactivation is a phenomenon that has the potential to cause microbial inactivation using visible light. It works on the principle that photosensitizers within the microbial cell can be activated using specific wavelengths to trigger a series of cytotoxic reactions. In the last few years, efforts to apply this intervention technology for food safety have been on the rise. This review article offers a detailed commentary on this research. The mechanism of photodynamic inactivation has been discussed as have the factors that influence its efficacy in food. Efforts to inactivate bacteria, fungi, and viruses have been analyzed in dedicated sections and so has the application of this technology to specific product classes such as fresh produce, dry fruits, seafood, and poultry. The challenges and opportunities facing the application of this technology to food systems have been evaluated and future research directions proposed. Thus, this review will provide insights for researchers and industry personnel looking for a novel solution to combat microbial contamination and resistance.

Treatment of peri-implantitis: clinical outcome of chloramine as an adjunctive to non-surgical therapy, a randomized clinical trial.

PURPOSE: To evaluate the adjunctive clinical effects of a chloramine to non-surgical treatment of peri-implantitis. MATERIAL AND METHODS: Eighteen individuals diagnosed with peri-implantitis (clinical signs of inflammation and progressive bone loss) on at least two implants were included. Clinical variables; plaque accumulation (Pl), probing depth (PD), clinical attachment level (CAL) and bleeding on probing (BoP), were recorded at baseline and at 3-month follow-up. Primary clinical efficacy variable was the change in the number of sites with BoP. The implants were randomized into two different treatment groups: test and control. Both implants received supra- and submucosal debridement by ultrasonic instrumentation supplemented with hand instruments. The implants assigned to the test group first received local applications of a chloramine gel (Perisolv™ ; RLS Global AB, Gothenburg, Sweden) followed by mechanical instrumentation. The oral hygiene was checked at 6 weeks. RESULTS: After 3 months, implants of both groups showed statistically significant reduction (P < 0.001) in the number of BoP-positive sites compared with baseline. The reduction of BoP-positive sites in the test group changed from 0.97 (SD ± 0.12) to 0.38 (SD ± 0.46), and in the control group from 0.97 (SD ± 0.12) to 0.31 (SD ± 0.42). Between-group comparisons revealed no statistically significant differences at baseline and after 3 months, for BoP or any of the other variables. CONCLUSION: In the present randomized clinical trial of peri-implantitis therapy; non-surgical mechanical debridement with adjunctive use of a chloramine is equally effective in the reduction of mucosal inflammation as conventional non-surgical mechanical debridement up to 3 months.

Pulsed light and antimicrobial combination treatments for surface decontamination of cheese: Favorable and antagonistic effects.

Postprocessing cross-contamination of cheese can lead to both food safety issues and significant losses due to spoilage. Pulsed light (PL) treatment, consisting of short, high-energy, broad-spectrum light pulses, has been proven effective in reducing the microbial load on cheese surface. As PL treatment effectiveness is limited by light-cheese interactions, the possibility to improve its effectiveness by combining it with the antimicrobial nisin was explored. The effect of natamycin, which is added to cheeses as an antifungal agent, on PL effectiveness was also investigated. Pseudomonas fluorescens, Escherichia coli ATCC 25922, and Listeria innocua were used as challenge microorganisms. Bacterial cultures in stationary growth phase were diluted to initial inoculum levels of 5 or 7 log cfu per cheese slice. Slices of sharp white Cheddar cheese and white American singles were cut in rectangles of 2.5 × 5 cm. For cheese slices receiving antimicrobial treatment before PL, slices were dipped in natamycin or nisin, spot inoculated with 100 µL of bacterial suspension, and then treated with PL. Cheese slices receiving PL treatment before antimicrobials were spot inoculated, treated with PL, and then treated with antimicrobials. The PL fluence levels from 1.02 to 12.29 J/cm2 were used. Survivors were enumerated by standard plate counting or the most probable number technique, as appropriate. All treatments were performed in triplicate, and the data were analyzed using a general linear model. Treatment with nisin or natamycin before PL decreased the effectiveness of PL for all bacteria tested. For instance, PL reduced P. fluorescens on Cheddar cheese by 2.19 ± 0.27 log after 6.14 J/cm2, whereas combination treatments at the same PL fluence yielded barely 1 log reduction. Inactivation of L. innocua on Cheddar was only 0.78 ± 0.01 log when using PL after nisin, compared with a 1.30 ± 0.76 log reduction by nisin alone. This was attributed to the absorption of UV light by the 2 antimicrobials, which diminished the UV fluence received by the bacteria. Increased inactivation was obtained when antimicrobials were applied after PL. On process cheese, a maximum reduction of 3.73 ± 0.96 log of L. innocua was obtained at 9.22 J/cm2 for PL followed by nisin, compared with 3.01 ± 0.48 by PL alone. This study demonstrates that antimicrobials may increase the antimicrobial effectiveness of PL on cheese surface, but the order of treatments is critical.

Pulsed light induced damages in Listeria innocua and Escherichia coli.

AIMS: Pulsed light (PL) is an upcoming nonthermal decontamination technology mainly used for surface sterilization. The objective of this study was to investigate the extent of cellular damage caused by PL treatments of Listeria innocua and Escherichia coli on a polysaccharide surface in order to gain knowledge about the main inactivation pathways. METHODS AND RESULTS: The impact of PL on the cellular ATP level was investigated as well as the bacterial ability to take up fluorescently labelled glucose (2-NBDG). Furthermore, the extent of DNA damages was assessed by qPCR. The ability of L. innocua and E. coli to photorepair under artificial daylight exposure was quantified. Finally, the induction of reactive oxygen species (ROS) and lipid peroxidation were studied by fluorometric detection of ROS and thiobarbituric acid reactive substances (TBARS). It is shown that intracellular ATP levels and glucose uptake ability do not correlate with the immediate loss of bacterial reproducibility, which indicates that cellular activity and energy may remain on a relatively high level, although growth on tryptic soy agar is not observable. Sequence specific investigation of PL induced DNA damages by qPCR revealed distinct differences between L. innocua and E. coli although the observed inactivation efficacy of PL by the culture based method was similar. Photoreactivation has been observed for both bacteria, a higher recovery rate of up to 2 log was seen in case of E. coli. Intracellular ROS and lipid peroxides were both detectable at relatively high fluencies with E. coli so the contribution of oxidative damage to microbial inactivation of PL cannot be excluded. CONCLUSIONS: Escherichia coli as well as L. innocua cells have proven to maintain residual cellular activity after having been exposed to PL even when they are not able to reproduce any more. High proportions of sublethal damages were also obvious with regard to occurring photoreactivation. The destruction of bacterial DNA seems to be the primary mechanism of inactivation of PL but the involvement of other factors like oxidative stress cannot be excluded. SIGNIFICANCE AND IMPACT OF THE STUDY: The observed data underline that bacteria are not immediately inactivated after exposure to PL as different indicators of cellular energy are still detectable even when cells do not reproduce on solid media any more. DNA is the primary target of PL, but as the extent of damage among different bacteria may not reveal their actual sensitivity, other destructive effects should also be considered.

Pulsed-light inactivation of pathogenic and spoilage bacteria on cheese surface.

Cheese products are susceptible to postprocessing cross-contamination by bacterial surface contamination during slicing, handling, or packaging, which can lead to food safety issues and significant losses due to spoilage. This study examined the effectiveness of pulsed-light (PL) treatment on the inactivation of the spoilage microorganism Pseudomonas fluorescens, the nonenterohemorrhagic Escherichia coli ATCC 25922 (nonpathogenic surrogate of Escherichia coli O157:H7), and Listeria innocua (nonpathogenic surrogate of Listeria monocytogenes) on cheese surface. The effects of inoculum level and cheese surface topography and the presence of clear polyethylene packaging were evaluated in a full factorial experimental design. The challenge microorganisms were grown to early stationary phase and subsequently diluted to reach initial inoculum levels of either 5 or 7 log cfu/slice. White Cheddar and process cheeses were cut into 2.5×5 cm slices, which were spot-inoculated with 100 µL of bacterial suspension. Inoculated cheese samples were exposed to PL doses of 1.02 to 12.29 J/cm(2). Recovered survivors were enumerated by standard plate counting or the most probable number technique, as appropriate. The PL treatments were performed in triplicate and data were analyzed using a general linear model. Listeria innocua was the least sensitive to PL treatment, with a maximum inactivation level of 3.37±0.2 log, followed by P. fluorescens, with a maximum inactivation of 3.74±0.8 log. Escherichia coli was the most sensitive to PL, with a maximum reduction of 5.41±0.1 log. All PL inactivation curves were nonlinear, and inactivation reached a plateau after 3 pulses (3.07 J/cm(2)). The PL treatments through UV-transparent packaging and without packaging consistently resulted in similar inactivation levels. This study demonstrates that PL has strong potential for decontamination of the cheese surface.

Experimental study for the decontamination of various surfaces from 99Mo using PVA/Borax/Al(OH)3 strippable hydrogel.

Polyvinyl alcohol (PVA) is a beneficial polymer capable of forming hydrogels helpful in a wide range of applications. Hydrogels based on cross-linking of PVA with borax, and able to incorporate with a decontaminating agent have been used in the decontamination of 99Mo from contaminated surfaces. Aluminum hydroxide has been introduced in the formulations of PVA-borax, to increase the gel efficiency for 99Mo decontamination from surfaces. The formulations were investigated with glass, stainless steel, and wood as examples of different surfaces. When the hydrogel is sprayed on different surfaces, it forms rapidly and adheres well. Moreover, the hydrogel was shown to efficiently decontaminate surfaces contaminated with 99Mo by a maximum value of decontamination factor (D.F) for glass, stainless steel, and wood to be 43.5, 31.3, and 19.6 respectively.

Effect of Bacteriophages against Biofilms of Escherichia coli on Food Processing Surfaces.

The bacterial adhesion to food processing surfaces is a threat to human health, as these surfaces can serve as reservoirs of pathogenic bacteria. Escherichia coli is an easily biofilm-forming bacterium involved in surface contamination that can lead to the cross-contamination of food. Despite the application of disinfection protocols, contamination through food processing surfaces continues to occur. Hence, new, effective, and sustainable alternative approaches are needed. Bacteriophages (or simply phages), viruses that only infect bacteria, have proven to be effective in reducing biofilms. Here, phage phT4A was applied to prevent and reduce E. coli biofilm on plastic and stainless steel surfaces at 25 °C. The biofilm formation capacity of phage-resistant and sensitive bacteria, after treatment, was also evaluated. The inactivation effectiveness of phage phT4A was surface-dependent, showing higher inactivation on plastic surfaces. Maximum reductions in E. coli biofilm of 5.5 and 4.0 log colony-forming units (CFU)/cm2 after 6 h of incubation on plastic and stainless steel, respectively, were observed. In the prevention assays, phage prevented biofilm formation in 3.2 log CFU/cm2 after 12 h. Although the emergence of phage-resistant bacteria has been observed during phage treatment, phage-resistant bacteria had a lower biofilm formation capacity compared to phage-sensitive bacteria. Overall, the results suggest that phages may have applicability as surface disinfectants against pathogenic bacteria, but further studies are needed to validate these findings using phT4A under different environmental conditions and on different materials.

Comparative evaluation of the antibacterial activity of red diode laser therapy and 0.2% chlorhexidine against Aggregatibacter actinomycetemcomitans on implant healing abutments: An ex vivo study.

Aims: The intraoral microbiota has a high potential to undergo dysbiosis, causing inflammatory changes with respect to the tissues surrounding either a natural tooth or an implant. Thus, the longevity of implant prosthesis depends on a thorough implant decontamination protocol. Among all the techniques available for doing so, laser is garnering increasing popularity, owing to minimal bleeding, high efficiency, and faster healing. However, limited literature exists regarding the superiority of lasers over chlorhexidine (CHX), the indisputable gold standard antibacterial chemical agent. The aim of this study was to compare the percentage of bacterial reduction of Aggregatibacter actinomycetemcomitans from implant healing abutments post red diode laser therapy versus 0.2% CHX treatment. Settings and Design: The current study had an ex vivo, observational, case-control design. Materials and Methods: Patients reporting for the second stage of the implant surgery were taken as the source of data and the healing abutments, the clinical samples. Eleven patients were chosen with one intraoral implant serving as the test site for laser treatment and another, the control site for CHX treatment. Microbiological analysis was performed via quantitative real time polymerase chain reaction to compare the bacterial reduction percentage after each treatment. Statistical Analysis Used: Repeated measures ANOVA and independent sample t test were used. Results: The mean bacterial viability of the test group (laser) was 1.2%-1.6%, and 0.6%-1.4% for the control group (CHX). The former caused a mean bacterial reduction of 96.1% while the latter, 96.3%. Both the treatments caused a highly statistically significant reduction of viable bacterial counts (P = 0.001). However, when compared, there was no statistically significant difference in the bacterial reduction, when compared in between the two (P = 0.902). Conclusion: Laser treatment is at par with chemical implant surface decontamination. It can help bypass the complications of CHX and revolutionize the protocols for implant surface decontamination.

Polymeric gel for surface decontamination of long-lived gamma and beta-emitting radionuclides.

Synthesis and characterization of strippable polymeric-gel solution based on a water-soluble polymer (PVA), plasticizing agent (glycerol), and chelating agent (8-Hydroxyquinoline) for the surface decontamination from 137Cs and 60Co was carried out. Decontamination of glass and PVC surfaces was investigated in the present study, as a function of various chelating agents, gel-layer thickness, and radioactivity level. The decontamination efficiency was up to 95% for both radionuclides after 24 h of contact time with the contaminated surface. The obtained results suggest that the decontamination process of 137Cs and 60Co by polymer gel is possible combined by two mechanisms: chemically and physically.