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Antimicrobial photodynamic therapy (aPDT) is a promising approach to control biofilms involved in periodontal diseases. However, certain challenges, such as staining of teeth, preferential interaction of photosensitizer (PS) with Gram-positive versus Gram-negative bacteria, and insufficient oxygen in hypoxic periodontal pockets have presented barriers to its use in the clinic. To overcome these challenges, a novel superhydrophobic (SH) film that generates airborne singlet oxygen has been developed. The SH-aPDT approach isolates the PS onto a topologically rough solid SH film on which channels allow air to diffuse to the PS surface, thus ensuring sufficient oxygen supply. Upon illumination, gas phase singlet oxygen (1O 2) is produced and diffuses from the SH surface to the underlying biofilm. The killing efficacy was assessed as a function of transmitted fluence (17.9–89.5 J/cm2) and chorin e6 loading (96–1110 nmol/cm2) by counting of colony forming units, biofilm metabolism by XTT and confocal microscopy. The decrease in viability of both Gram-positive and Gram-negative bacteria in a multi-species biofilm was found to be linearly dependent on the fluence as well as the loading of the PS up to 71.6 J/cm2 when 1110 nmols/cm2 of chlorin e6 was used. A > 4.6 log bacterial reduction was observed under these conditions (p < 0.05). This novel SH-aPDT approach shows promise as an effective method to disinfect multi-species bacterial biofilms associated with periodontal disease and will be evaluated in animal models in future studies. [Display omitted] • A superhydrophobic film delivered airborne singlet oxygen to multispecies biofilms. • Biofilms associated with periodontitis were effectively eradicated by SH-aPDT. • Killing was linear with increasing fluence and photosensitizer loading for all species. • CFU reductions of >4.6 log 10 were achieved at 71.6 J/cm2 using a red LED. • Gram-negative and Gram-positive species were killed equivalently. [ABSTRACT FROM AUTHOR]

To assess the effect of curcumin-encapsulated Pluronic® F-127 (Cur-Plu) during antimicrobial photodynamic therapy (aPDT) over duo-species biofilm of Streptococcus mutans and Candida albicans. Thermal analysis, optical absorption, and fluorescence spectroscopy were evaluated. Minimum inhibitory concentration (MIC) and minimum bactericidal/fungal concentration were obtained. The biofilms were cultured for 48 h at 37 °C and treated according to the groups: P + M + L + (photosensitizer encapsulated with Pluronic® F-127 + light); P + D + L + (photosensitizer incorporated in 1% DMSO + light); P − M + L + (no Pluronic® F-127 + light); P − D + L + (1% DMSO + light); P − L + (Milli-Q water + light); P + M + L − (photosensitizer encapsulated with Pluronic® F-127 no light); P + D + L − (photosensitizer in 1% DMSO, no light); P − M + L − (Pluronic® F-127 no light); P − D + L − (1% DMSO, no light); P − L − (Milli-Q water, no light; negative control group); CHX (0.2% chlorhexidine, positive control group); and NYS (Nystatin). Dark incubation of 5 min was used. The groups that received aPDT were irradiated by blue LED (460 nm, 15 J/cm2). Cell viability of the biofilms was performed by colony-forming units (CFU/mL) and confocal microscopy. Two-way ANOVA followed by Tukey's post hoc test was used at a significance level of 5%. P + D + L + and P + M + L + groups exhibited better log-reduction for both Candida albicans and Streptococcus mutans biofilms than P − M + L + , P − L + , and P − D + L + experimental groups. Furthermore, P + M + L + and P + D + L + showed greater reduction for Candida albicans than for Streptococcus mutans. aPDT mediated by Cur-Plu can be a potential strategy for biofilm control against duo-species biofilm of Streptococcus mutans and Candida albicans. [ABSTRACT FROM AUTHOR]

This review describes nanoparticle and dye diffusion in bacterial biofilms in the context of antimicrobial photodynamic inactivation (aPDI). aPDI requires the diffusion of a photosensitizer (Sens) into the biofilm and subsequent photoactivation of oxygen for the generation of reactive oxygen species (ROS) that inactivate microbes. Molecular diffusion in biofilms has been long investigated, whereas this review is intended to draw a logical link between diffusion in biofilms and ROS, a combination that leads to the current state of aPDI and superhydrophobic aPDI (SH‐aPDI). This review should be of interest to photochemists, photobiologists and researchers in material and antimicrobial sciences as is ties together conventional aPDI with the emerging subject of SH‐aPDI. [ABSTRACT FROM AUTHOR]

Abstract The biofilm accumulation over the composite resin restorations can contribute to the formation of secondary caries. In this way, antibacterial restorative composite resins are highly desired. Then, the purpose of this study was to modify a composite resins using Ag doped ZnO nanoparticles (NPs), evaluate the antibacterial and mechanical properties of the modified composite resin. The ZnO/AgNPs were synthesized by two different routes, polymeric precursor and coprecipitation methods, and characterized by thermal decomposition, X-ray diffraction, specific surface area by N 2 desorption/desorption and scanning electron microscopy (SEM). Antibacterial activity of composite resin specimens (4 mm in height and 2 mm in diameter; n = 15) modified by ZnO/Ag nanoparticles was performed against 7-days Streptococcus mutans biofilm. Colony forming units (CFU/mL) were used to evaluate the bacterial activity. Additionally, the morphology and the bacteria adherence area were analyzed by SEM images. Cylindrical specimens (6 mm in height and 4 mm in diameter; n = 20) of the composite resin containing ZnO/Ag NPs were prepared to perform compressive strength in a universal mechanical test machine, and the surface of fractured specimens was analyzed by EDX element mapping to verify NPs homogeneity. The normal distribution was confirmed and the two-way analysis of variance (ANOVA) and Tukey's test for pair comparison were performed. The nanospheres of ZnO/Ag lead to a better biofilm inhibition, than nanoplates. No difference on compressive strength was found for the composite resin modified by ZnO/Ag nanoplates. Based on these results, this material could be a good option as a new restorative material. Highlights • ZnO micro and nanoparticles with antimicrobial properties were satisfactorily synthetized by the different routes. • The composite resin containing ZnO particles significantly inhibit the S. mutans biofilm. • The compressive strength of the composite resin containing Ag/ZnO nanoplates did not drastically changed. [ABSTRACT FROM AUTHOR]

Highlights • The modification of the composite resin using pure and Ag decorated TiO 2 can decrease S. mutans biofilm formation over the composite resin surface. • The properties of the modified composite resin did not change after the modification with TiO 2 /Ag (PREC POL). • The TiO 2 /Ag nanospheres obtained by polymeric precursor synthesis seems to be the best nanomaterial. Abstract Objective The aim of this study was to evaluate the antibacterial activity of a composite resin modified by TiO 2 and TiO 2 /Ag nanoparticles and their influence over different properties. Methods TiO 2 and TiO 2 /Ag NPs were synthesized by polymeric precursor and microwave-assisted hydrothermal methods and then, characterized by different techniques. Direct contact test was performed using Filtek™ Z350XT blended with 0.5; 1 and 2% (wt.) of NPs against Streptococcus mutans to determine the best concentration to the other tests. After that, the modified composite resin was tested against S. mutans 7-day biofilm (CFU/mL). Also, compressive and diametral tensile strength (n = 40), degree of conversion (n = 25) and surface roughness (n = 50) was performed. The data were analyzed by ANOVA and Tukey's test for multiple comparison at 5% significance level. Results The direct contact test demonstrates that by increasing the nanoparticle content, the bacterial growth is significantly reduceed (p < 0.05). The inclusion of 2% of TiO 2 /Ag NPs significantly decreased (p < 0.05) the biofilm accumulation of S. mutans on the composite resin surface compared to the control Group. The TiO 2 NPs treated with an organosilane increased compressive strength of composite resin (p < 0.05). Degree of conversion remained unchanged (p > 0.05) and the surface roughness increased with the NPs (p < 0.05), except for the TiO 2 by polymeric precursor Group (p > 0.05). Significance The development of an antibacterial dental restorative material that hinder S. mutans biofilm without sacrificing the mechanical and physical properties is desirable in dental material science. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to evaluate the application of Er:YAG and Er,Cr:YSGG lasers during osteotomy in bovine bone blocks. Background data: Er:YAG/Er,Cr:YSGG lasers for osteotomy procedures have been used to induce tissue ablation without thermal damage. However, even these lasers can induce thermal damages, which can cause a delay on the bone healing. Materials and methods: Sixty standardized bovine bone mandible samples were divided into three groups with 20 samples each: Group 1, Bur; Group 2, Er: YAG laser; and Group 3, Er,Cr:YSGG laser. Two irradiations/cuts were made in each sample. The first was performed until the sample was completely separated into two fragments, and the time required for this procedure was recorded in seconds. The second irradiation/cut was made the same way as the first one; however, it was made partially, without separating the sample into two fragments, but rather making sulci ~ 1.5-2 mm deep. Ten samples in each group were used to evaluate the surface morphology of the osteotomy by scanning electron microscopy (SEM), while the other 10 samples were submitted to descriptive histological analysis. Results: The bur was the instrument that performed the osteotomy in the shortest amount of time (p<0.05). All the instruments caused thermal damage; however, the Er,Cr:YSGG laser was the only type that induced carbonization. Conclusions: The Er:YAG laser induced the lowest degree of thermal damage in bone tissue after osteotomy; however, a shorter clinical time was required to perform the osteotomy in the bur group. [ABSTRACT FROM AUTHOR]

Purpose: to evaluate the prevalence of nonnutritive sucking habits in preschool children from Araraquara-SP, seeking to better understand their characteristics, distribution and relation to breastfeeding. Method: application of a questionnaire sent to parents or guardians. The sample comprised 1371 children aged between 6 months and 5-year old, where 702 children (51.2%) had deleterious habits, from a total of 812 reported habits. Results: the habits were more prevalent in women (55%) and aged between 6 months and 2 years. The most commonly found practice was sucking a pacifier (30%), followed by suction bottle (18.4%) and sucking (7.6%), there was no association between the type of habit and socioeconomic status. From the participating children, 1,239 (90.4%) were breastfed, and the length of breastfeeding was most prevalent between 6 months and 12 months (43%), not necessarily exclusive but for a period not less than the recommended by WHO. Conclusion: there was an association between duration of breastfeeding in the presence and type of habit, since children who received breastfeeding for a period exceeding 12 months tended not to develop harmful habits. The results show that the greater the duration of breastfeeding is, the lower becomes the prevalence of habits. [ABSTRACT FROM AUTHOR]