Ultrasonic Activation Research Articles

Sealing Ability of Bioceramic Sealer after Ultrasonic Activation of Different Root Canal Irrigating Solutions

Aim To evaluate and compare the sealing ability of bio ceramic root canal sealer after ultrasonic activation of root canal irrigation solutions 3% NaOCl , 40% Citric acid & Neem leaf extract .  Materials and Methods In this study, 42 mandibular premolar teeth with single roots and canals were divided into three groups for irrigation: 3% NaOCl, 40% citric acid, and Neem leaf extract. After access preparation and glide path creation with a #10 K-file (0.02 taper), the canals were instrumented using a crown-down technique to an ISO size of 30, with saline as the irrigant. Ultrasonically activated irrigation was used, followed by saline in all groups. The canals were obturated with Dentsply Gutta- percha and Bio C sealer, 1mm short of the working length, and sealed with temporary restorations. Teeth were incubated at 37°C for 3 days, and horizontal sections at 3mm from the apex were taken. Confocal laser scanning microscopy measured sealer penetration, and statistical analysis was conducted to compare results between groups.  Results The results suggest that 40% citric acid is the most effective irrigant for enhancing sealer penetration into dentinal tubules at the apical third, both in terms of percentage and depth of penetration, compared to 3% NaOCl and neem leaf extract. This indicates that citric acid may improve the sealing ability of root canal treatments more effectively than the other tested irrigants.  Conclusion The results suggest that 40% citric acid is the most effective irrigant for enhancing sealer penetration into dentinal tubules at the apical third, both in terms of percentage and depth of penetration, compared to 3% NaOCl and neem leaf extract. This indicates that citric acid may improve the sealing ability of root canal treatments more effectively than the other tested irrigants.

Синтез 5-амино-3-арил-1H-пиразол-4-карбонитрилов на основе гидразинов или бензгидразидов в условиях ультразвуковой активации

Pyrazoles containing amino and carbonitrile groups have a wide range of biological activities, including antimicrobial, antiinflammatory, antitumor, antioxidant, and are used to create pesticides and dyes. Also, these compounds are synthons for the preparation of various polyheterocyclic compounds. New potentially biologically active 5-amino-3-aryl-1H-pyrazole-4-carbonitriles containing pharmacophoric substituents have been obtained via three-component condensation reactions of malonic dinitrile with substituted aromatic aldehydes and benzhydrazides or hydrazines. This work considers the limits of applicability of hydrazines and hydrazides as weak nucleophiles in similar processes. The described target compounds have been synthesized using the «green chemistry» approach under ultrasonic activation in water or a mixture of water and isopropyl alcohol in the presence of triethylamine as base catalyst. The applicability of this environmentally friendly, economical and efficient approach for the synthesis of nitrogen-unsubstituted (7, 8) and N-aryl- (4, 6) or N-aroyl-substituted (1–3) pyrazole-4-carbonitriles has been demonstrated. The target pyrazole-4-carbonitrile (2) is formed and Schiff base (2’) is released as a by-product in the reaction of the weak binucleophile 3-nitrobenzhydrazide with 4-benzyloxy-3-methoxybenzaldehyde and malonic dinitrile. Step-by-step syntheses have shown that the initial reaction of a three-component interaction can be either croton condensation or the formation of a Schiff base. In any case, during subsequent heterocyclization, unstable substituted pyrazolines are formed, which aromatize to the target pyrazoles in the presence of atmospheric oxygen under synthesis conditions. The composition and structure of the products have been confirmed by elemental analysis, NMR 1H, 13C spectroscopy, HSQC, and HMBC heteronuclear correlations.

Impact of LASER activated irrigation on the retrievability of Guttaflow bioseal (in-vitro study)

BackgroundThis study aimed to evaluate the efficiency of diode LASER activated irrigation in the removal of GuttaFlow Bioseal root canal filling material during retreatment.Materials and subjectsRoot canals of forty-five single-rooted human mandibular premolar teeth were prepared with ProTaper Universal rotary system and obturated with lateral condensation obturation technique using Gutta Percha and Roeko GuttaFlow Bioseal root canal sealer. All specimens were retreated with ProTaper Universal Retreatment System files then divided to three different groups according to the technique of activation of irrigation. Samples were sectioned, and the residual filling remnants were captured using digital camera attached to microscope. Data was collected by three different interpreters, to eliminate the subjectivity of the process, using the ImageJ Software. The mean value of the data was obtained and evaluated statistically. The significance level was set at P ≤ 0.05.ResultsThe remaining filling materials in the canals irrigated with ultrasonic activation (6.17 ± 1.42 at coronal level, 10.93 ± 1.91at middle level, and 14.58 ± 2.23 at apical level) were less than these irrigated with LASER activation (15.87 ± 3.78 at coronal level, 21.28 ± 4.44 at middle level, and 27.06 ± 2.68 at apical level). Maximum amount of remaining filling materials was present in the canals irrigated with passive side-vented syringe (23.07 ± 3.22 at coronal level, 38.09 ± 7.27 at middle level, and 34.24 ± 9.77 at apical level).ConclusionThe activation of irrigation techniques used were incapable of complete removal of filling material at root canal walls.

Evaluation of pulp tissue dissolving efficiency of sodium and calcium hypochlorite solutions activated by ultrasonics and laser: an in vitro study

ObjectivesThis study aimed to compare the tissue dissolving capacities of sodium and calcium hypochlorite [NaOCl and Ca(OCl)2] solutions applied without activation or with two irrigant activation methods.Materials and MethodsOne hundred and eight dentin cavities were prepared. Preweighed tissue pieces were placed in these dentin cavities, and samples were divided into nine groups of twelve. In groups 1, 2, and 3, NaOCl was used with non-activation (NA), passive ultrasonic (PUA), and laser activation (LA). With the same techniques, Ca(OCl)2 was used in groups 4, 5, and 6, and distilled water was used in groups 7, 8, and 9. The weight loss of tissue samples was calculated and analyzed using Two-way ANOVA and Duncan tests.ResultsDistilled water groups showed no tissue dissolution in any conditions. NaOCI and Ca(OCI)2 showed statistically similar dissolving effectiveness when used with the same technique. Activated groups dissolved significantly greater tissue than non-activated ones, the highest in LA.ConclusionsCa(OCI)2 can be an alternative to NaOCl; for both, the first choice of activation may be the LA.

Seasonal variation in the ultrasonic vocal activity of Humboldt's flying squirrel (Glaucomys oregonensis).

Most mammals rely on vocal communication to increase survival and reproductive success. While the functions of audible vocalizations have been well-studied across mammal species, ultrasonic vocalizations in small mammals outside of bats are less understood. North American flying squirrel species (Glaucomys spp.), including the newly described Humboldt's flying squirrel (Glaucomys oregonensis), produce numerous call-types that extend into the ultrasonic range. To investigate the potential function of ultrasonic call-types in the Humboldt's flying squirrels, we used ultrasonic recorders to record squirrels in the wild across multiple seasons to determine if there are temporal and seasonal patterns in nightly vocal activity and rates of different call-types. We recorded Humboldt's flying squirrels in two geographic locations - Humboldt and San Bernardino counties-in California from 2018 to 2022 in the summer and winter across multiple study areas. We found that although seasonal weather conditions differ between locations, flying squirrels in Humboldt and San Bernardino had similar vocal activity patterns across nightly active periods between locations and between summer and winter. Nightly activity patterns of when the three main chirp-like call-types (arc chirps, tonal chirps, upsweeps) were given varied between seasons in both geographic locations, and these call-types were given at greater rates in the summer in San Bernardino, but rates did not vary by season in Humboldt. Trills, the most structurally complex of the four main call-types, were produced more in the summer than in winter, and also differed in their nightly activity patterns, in both geographic locations. Flying squirrels may use certain call-types earlier or later in the nightly active period due to their potentially varying functions, and may produce more trills in the summer coinciding with the breeding season. Further understanding of the function of different call-types can provide insight into social, foraging, and antipredator behavior of this nocturnal and elusive species.

Evaluating the Impact of Ultrasonic Irrigation on Bacterial Levels and Activity Following Chemomechanical Procedures

IntroductionThis single-arm interventional trial aimed to investigate the efficacy of ultrasonic irrigation as a supplementary disinfection approach after chemomechanical procedures (CMP) using molecular techniques based on ribosomal RNA (rRNA) and rRNA genes (referred to as DNA). MethodsSamples were collected from 35 single-rooted teeth with radiographic evidence of apical periodontitis. Samples were taken after gaining root canal access (S1), (S2), and ultrasonic irrigation (S3). DNA-targeted quantitative polymerase chain reaction using universal primers was used to estimate total bacterial levels, while rRNA-targeted quantitative polymerase chain reaction was used to assess bacterial activity. Ratios between rRNA and DNA levels were calculated to search for active bacteria in the samples (rRNA/DNA ≥ 1). Wilcoxon matched-pairs signed-rank test was used to compare the differences in DNA levels between samples and DNA and rRNA levels within samples (P < .05). ResultsDNA-based methods revealed a significant decrease in bacterial levels from S1 to S2 and S2 to S3 (both P < .05). Notably, 11 out of 35 (31.4%) root canals did not harbor bacterial DNA after CMP, whereas ultrasonic activation increased DNA-negative samples to 17 (48.6%). However, all DNA-positive samples were also positive for rRNA, with significantly higher rRNA than DNA levels (P < .05), indicating bacterial activity at the sampling time. ConclusionsUltrasonic irrigation improved the disinfection of root canals after CMP by reducing bacterial levels. However, persisting bacteria remained active in the root canals after CMP and ultrasonic irrigation.

Main findings from the use of ozone therapy alone or combined with conventional treatments in root canal treatment: a systematic review

Introduction: The positive effects of ozone on biological properties include antimicrobial, immunostimulating, and biosynthetic impacts used in the treatment and maintenance of good oral hygiene. Ozone results in alteration in the metabolism of cells by raising the partial pressure of oxygen in tissues which improves the transporting capacity of oxygen in the blood. Ozone causes more blood supply to the ischemic zones due to surgical interventions like tooth extractions and implant placement. In this context of decontamination of root and periapical canals, ozone has emerged as an important sanitizer. Objective: It was to develop a systematic review of the literature to list the main findings of the use of ozone therapy alone or combined with conventional treatments in the treatment of root canals. Methods: The PRISMA Platform systematic review rules were followed. The search was carried out from March to June 2024 in the Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: A total of 122 articles were found, 35 articles were evaluated in full and 11 were included and developed in the present systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 25 studies with a high risk of bias and 22 studies that did not meet GRADE and AMSTAR-2. Most studies did not show homogeneity in their results, with X2=88.5%&lt;50%. Results and Conclusion: It is concluded that ultrasonic and sonic ozone activation resulted in less pain in patients undergoing single-session endodontics compared to no ozone treatment. Ozonated olive oil with zinc oxide and olive oil paste with zinc oxide demonstrated good clinical and radiographic success for pulpectomy of primary teeth. Furthermore, low-intensity laser and ozone therapy are useful methods for postoperative pain in vital symptomatic teeth, but they are not superior to each other.

Efficacy of sonic and ultrasonic activation on irrigant penetration in different tapered preparations: An in vitro study

ABSTRACT Background: The traditional syringe needle irrigation method would compromise on cleaning the intricacies of the complex root canal system. Current literature has focused on the benefits of various irrigant activation techniques. The present study aims to evaluate the irrigant penetration in extracted single-rooted teeth using various irrigant activation systems in different tapered preparations. Materials and Methods: One hundred and twenty-four single-rooted teeth were selected for the present study. They were standardized at the level of cementoenamel junction and shaped to 30 size using 4% and 6% taper rotary instruments under a standard irrigation regimen. Once the complete root canal preparations were done based on activation protocols, they were divided into four groups as Group 1: Four percent preparation sonic activation (n = 31), Group 2: Six percent preparation sonic activation (n = 31), Group 3: Four percent preparation ultrasonic activation (n = 31), and Group 4: Six percent preparation ultrasonic activation (n = 31). A radiopaque solution in conjunction with radiography was utilized to evaluate the penetration of irrigants into the canal. Radiographs were taken after dye injection to measure the length of irrigant penetration in each technique. Results were statistically analyzed using SPSS software. One-way ANOVA and Post hoc Tukey tests were performed. Results: The results of the study revealed that ultrasonic activation after 6% taper instrumentation was better followed by ultrasonic activation after 4% taper instrumentation (P &lt; 0.05). The results revealed a statistically significant difference (P &lt; 0.05) between the irrigation techniques. Conclusion: Ultrasonic irrigant activation proved to be a better and an effective technique for cleaning the root canal.

Comparative Evaluation of Different Methods of Activation of Chelating Solution for Smear Layer Removal in the Apical Portion of the Root Canal Using a Scanning Electron Microscopy: An In Vitro Study.

Background The smear layer has an adverse effect on the sealing of root canals during obturation, and it is the main reason for the failure of root canal treatment.Root canal irrigation using a conventional irrigation system is ineffective for smear layer removal, especially from the apical third region, where mostlateral canals are present. For successful endodontic treatment, the smear layer should be removed from the apical third region using an effective irrigation activation system. Aim This study aimed to compare smear layer removal by conventional irrigation, XP Endo Finisher (XPF), endoactivator (EA), passive ultrasonic activation, and root canal brushusing 17% ethylenediaminetetraacetic acid (EDTA) as a chelating solution and 5.25% sodium hypochlorite after chemomechanical preparation, using scanning electron microscopy (SEM). Method A total of 50 extracted human mandibular single canal premolars with mature roots were selected for this study. Samples were decoronated to obtain a standard working length (WL) of 15 mm. Canal patency was achieved using a 10 k file. Samples were sealed with sticky wax to obtain the vapor lock effect. Biomechanical preparation is done till F3. The samples were divided into five groups according to the final irrigation activation protocol: Group 1, control group; group 2, XPF; group 3, EA; group 4, passive ultrasonic irrigation (PUI); and group 5,, root canal brush. Samples were divided into two equal halves longitudinally. Each sample was analyzed for a smear layer under SEM at 2000x magnification. Statistical analysis was done using the one-way Anova "F" test and Tukey's post-hoc test. Results Group 3 showed the least presence of a smear layer, followed by groups 4, 2, 5, and 1. All the groups exhibited highly significant differences between each other (p < 0.001). Group B shows no significant difference with groups C, D, and E. Group C shows no significant difference with groups D and E. Group D shows no significant difference with group E. Conclusion The EA removes the smear layer effectively as compared with other groups. All the irrigation activation system shows the presence of smear layer. No activation systems were able to remove the smear layer completely.

Comparative effects of the conventional, ultrasonic, and laser-activated irrigation on penetration depth of three photosensitizers in the root canal system

ObjectivesThis study compared the effects of conventional, ultrasonic, and laser-activated irrigation (LAI) on penetration depth of three photosensitizers (PSs) in the root canal system. Materials and MethodsIn this in vitro, experimental study, 120 extracted anterior teeth were decoronated such that the remaining root length was standardized at 12 mm. After root canal instrumentation with the ProTaper rotary system and irrigation with 5.25% NaOCl, the roots were assigned to 12 groups for the application of toluidine blue (TB), curcumin, and phycocyanin PSs combined with the LAI using erbium laser with 0.4 mm and 0.6 mm tips, ultrasonic activation, and conventional irrigation. The specimens were sectioned apicocoronally, and the dye penetration depth was quantified in the coronal, middle, and apical thirds under a stereomicroscope at x20 magnification. Data were analyzed by the Kruskal-Wallis and Dunn test (alpha=0.05). ResultsThe effects of irrigation technique, PS type, and their interaction on dye penetration depth were significant at the apical, middle, and coronal thirds (P < 0.0001). TB + LAI with 0.4- and 0.6-mm laser tips showed the highest penetration depth while phycocyanin + LAI or conventional irrigation showed the lowest penetration depth at all areas. Dye penetration depth was the highest in the coronal, and the lowest in the apical third. ConclusionThe LAI technique with erbium laser (0.4- and 0.6-mm tips) enhanced the penetration depth of TB. The tested irrigation techniques had no significant efficacy for enhancement of the penetration depth of curcumin and phycocyanin.

Efficacy of Different Irrigation Needles and Ultrasonic Activation on Calcium Hydroxide Removal: A Micro-CT Study Using 3D-Printed Endodontic Models

IntroductionThe aim of this study was to evaluate the efficacy of different irrigation needles and passive ultrasonic activation in removing Ca(OH)2 from an endodontic model that duplicated a root canal configuration of a human natural tooth. MethodsAn extracted human maxillary premolar was subjected to root canal preparation and scanned with microcomputed tomography. A 3-dimensional reconstruction model of the natural tooth was printed to endodontic models using a polyjet printer. The root canals of the models were filled with Ca(OH)2 paste and divided into 2 groups based on the irrigation protocol: conventional syringe-needle irrigation (conventional group) and passive ultrasonic irrigation (PUI) group. Each group was subdivided into 3 groups (n = 10) according to the type of needle: half-cut, side-vented, and TruNatomy irrigation needle. Microcomputed tomographyimaging was used to assess the percentage of reduction of Ca(OH)2. Data were analyzed using two-way analysis of variance test (α = .05). ResultsThe side-vented and TruNatomy irrigation needles showed significantly higher percentage reductions than the half-cut needle (P < .05) in the conventional irrigation group. The PUI group showed significantly higher percentage reductions of Ca(OH)2 than the conventional group regardless of the type of needle (P < .05). However, no significant difference was found among the needles in the PUI group. ConclusionsThe type of irrigation needle and the use of PUI influenced the removal efficacy of Ca(OH)2. PUI enhanced the removal of Ca(OH)2 regardless of the type of irrigation needle.

Comparative Evaluation of Activated and Nonactivated Microbubbles on the Efficacy of Bleaching Agents.

Intracoronal bleaching serves as a conservative option for nonvital teeth that exhibit discoloration.Hydrogen peroxide (H2O2) is frequently utilized in bleaching processes owing to its capability to produce free radicals.The main drawbacks of the currently available bleaching agents are the occurrence of cervical resorption and the multiple dental visits to achieve the desired result. Therefore, in our study, to address the limitations associated with cervical resorption and extended treatment duration for badly stained teeth, an attempt was made to incorporate a whitening agent (35% H2O2) with microbubbles. This study aimed tocompareandevaluatetheeffect ofactivated and nonactivated microbubbles on the efficacy of bleaching agents. Forty-five human central incisors were collected and divided into three groups:Group I (HP), H2O2 plain(n= 15) (Control); Group II (HPM), H2O2-infused microbubbles without ultrasonic activation (n= 15) (experimental group); and Group III (HPMU), H2O2-infused microbubbles with ultrasonic activation (n= 15) (experimental group).The crowns were artificially stained. Microbubbles containing 35% H2O2were generated using the probe sonication method.The bleaching agent H2O2 plain (0.04 mL) was syringed into the pulp chamber in group I, while H2O2-infused microbubbles (0.04 mL) were syringed into group II and group III. Group III was further activated ultrasonically. The evaluation of color shade differences was conducted using the Vita Lumin shade guide at three time points: baseline, day 7, and day 14. Data regarding color change using Vita shade were investigated for normality using theKolmogorov Smirnov test and assessed a non-normal distribution.Intergroup comparisons at each particular time interval (baseline, day 7, and day 14) were analyzed using the Kruskal-Wallis H test followed by multiple pairwise comparisons using the Adjusted Bonferroni post hoc test. Intragroup comparisons between different time intervals were analyzed using related samples from Friedman's test followed by multiple pairwise comparisons using the post hoc Dunn test. The level of statistical significance was determined at P< 0.05. There was no statistical difference in the baseline values of all three groups. Group I (HP) exhibited an average increase of three Vita Lumin shade tabs on day 7 and day 14, respectively, whereasGroup II (HPM)exhibited an average increase of six and four Vita Lumin shade tabs on day 7 and day 14, respectively, and Group III (HPMU)exhibited an average increase of 10 and 3 Vita Lumin shade tabs on day 7 and day 14, respectively. Microbubbles containing H2O2 were more efficient and faster than plain H2O2 for bleaching, and the efficacy of bleaching was enhanced when activated using ultrasonic technology.

Evaluation and comparison of the efficiency of ultrasonically activated intracanal irrigants grapeseed and pineapple extract in removing smear layer from the apical third of the root canal: An in vitro SEM analysis

ABSTRACT Aim: This study aims to evaluate and compare the efficiency of grapeseed and pineapple extract in removing smear layer from the apical third of root canal, with and without ultrasonic activation. Methods: Eighty single-rooted permanent teeth were divided into two main groups: Group I: conventional syringe irrigation and Group II: ultrasonic activation. Each group was subdivided into two experimental groups, i.e. grapeseed and pineapple extract and one control group, i.e., 17% ethylenediaminetetraacetic acid (EDTA). For each subgroup, instrumentation was done using ProTaper Gold up to size F3 and irrigated with 5 mL of the respective irrigant, followed by a final rinse of 2.5 mL of 5.25% NaOCl. For Group II, the respective irrigant was ultrasonically activated for 1 min, followed by a final rinse of 2.5 mL of 5.25% NaOCl. Smear layer evaluation was done with scanning electron microscope, and data were statistically analyzed. Results: In Group I, both pineapple and grapeseed extracts were more effective than 17% EDTA in removing smear layer from the apical root canal. However, in Group II, 17% EDTA showed highest efficacy in smear layer removal, followed by pineapple and grapeseed extracts (P &lt; 0.05). Conclusion: Natural extracts such as pineapple and grapeseed seeds extracts exhibit potential for smear layer removal in the apical third, without the disadvantage of dentinal erosion from synthetic smear layer removing agents.

Chondroprotection of articular cartilage integrity: Utilizing ultrasonic scalpel and hyperosmolar irrigation solution during cutting

ObjectivesUltrasonic (US) cutting of cartilage in orthopaedic surgery has received little attention despite its potential to reduce chondrocyte death which could enhance cartilage repair. We aimed to investigate whether an ultrasonically-vibrating scalpel to cut human articular cartilage could reduce chondrocyte death, and to determine if hyper-osmolarity could provide chondroprotection during the procedure. MethodsA scalpel (no. 15) was mounted on an ultrasonic transducer to resonate at 35 ​kHz with 30 ​μm vibrational displacement. Thirty-six fresh human femoral cartilage samples were divided into four groups based on ultrasonic activation (US or non-US) and saline osmolarity (300 or 600 mOsm/L). Cell viability was assessed using a live/dead cell assay and analysed quantitatively by confocal microscopy. Histology illustrated tissue surface changes at the cut site. ResultsThe overall chondrocyte death percentage at both the US and non-US cut sites showed comparable results (p ​> ​0.05) in both osmolarities. However, the zone of chondrocyte death was reduced by 31 ​± ​5% and 36 ​± ​6%, respectively, when comparing US cutting at 300 mOsm/L and 600 mOsm/L to the control group (non-US cutting; 300 mOsm/L) (p ​< ​0.05). The width of the cut was consistent at both sites, regardless of the method of cutting. ConclusionCutting human cartilage with US in the presence of 300 or 600 mOsm/L media was chondroprotective compared to normal (non-US) scalpel cutting in 300 mOsm/L medium. These results suggest chondroprotection can be achieved while cutting using a US scalpel and raised osmolarity, potentially improving cartilage regeneration and repair following injury.

Comparative evaluation of Postoperative Pain following Ultrasonic activation and Root Canal Obturation with Bioceramic Sealers versus Epoxy-Resin in Partially Edentulous Patients Rehabilitated with Tooth-Supported Overdentures : RCT

Comparative evaluation of Postoperative Pain following Ultrasonic activation and Root Canal Obturation with Bioceramic Sealers versus Epoxy-Resin in Partially Edentulous Patients Rehabilitated with Tooth-Supported Overdentures : RCT

Nitric Oxide‐Actuated Titanium Dioxide Janus Nanoparticles for Enhanced Multimodal Disruption of Infectious Biofilms

AbstractSonodynamic therapy (SDT) is promising for combating deep‐seated infectious diseases by generating substantial reactive oxygen species (ROS) through the profound tissue penetration capabilities of ultrasound. However, the compact protective structures of bacterial biofilms present a formidable challenge, impeding ROS efficacy. Given that ROS have a limited diffusion range and current sonosensitizers struggle to infiltrate biofilms, complete eradication of pathogenic bacteria often remains unachieved. In this study, mesoporous titanium dioxide (TiO2) nanoparticles are engineered asymmetrically coated with a thin layer of Ag and loaded with L‐arginine (LA) to construct ultrasound‐propelled nanomotors. These Ag‐TiO2‐LA Janus nanoparticles demonstrate robust self‐propulsion upon ultrasonic activation, allowing for deeper penetration into biofilm matrices and enhancing localized biofilm disruption through improved SDT outcomes. Additionally, the incorporation of Ag not only broadens TiO2’s absorption spectrum but also confers photothermal capabilities upon NIR laser excitation at 808 nm. The Ag‐TiO2‐LA nanomotor amalgamates TiO2’s sonodynamic potential with Ag's photothermal properties, forging a versatile antimicrobial agent capable of efficient biofilm penetration and a synergistic antibacterial effect when subjected to dual NIR and ultrasound stimuli. This innovative, singularly‐structured nanoparticle stands out as an effective combatant against bacterial biofilms and accelerates the healing process of infected wounds, showcasing potential for multifaceted clinical applications.

Can antimicrobial photodynamic therapy serve as an effective adjunct protocol for disinfecting the necrotic root canal system? A randomized controlled study

BackgroundBacterial infection plays an important role in persistent periapical lesions and inadequate disinfection of root canals is considered the biggest factor responsible for endodontic treatment failure. Antimicrobial Photodynamic Therapy (aPDT) has become the latest choice to eradicate microorganisms in root canals.ObjectiveThis study aims to evaluate the effectiveness of Antimicrobial Photodynamic Therapy (aPDT) in bacterial count reduction compared to Passive Ultrasonic Activation (PUI) and Ca(OH)2 dressings.Materials and methodsForty-five anterior single canal teeth with medium-sized periapical lesions (2–5 mm) were divided into three groups according to the disinfecting technique (each group consists of 15 canals with 1:1:1 allocation ratio): Group A: Ca(OH)2 dressing. Group B: Passive Ultrasonic Activation (PUI). Group C: Antimicrobial Photodynamic Therapy (aPDT). Direct bacterial viable count method was used to count the colonies forming units (CFU) before and after the disinfecting and the bacterial count reduction was estimated, the statistical analysis was performed at a 95% confidence level using the Chi-square and Mann–Whitney U test.ResultsaPDT showed no statistically significant difference when compared to passive ultrasonic irrigation (P > 0.05) but showed higher and more promising results when compared to Ca(OH)2 dressings (P < 0.05).ConclusionsaPDT has the ability and effectiveness as a disinfecting technique in necrotic and infected root canals.Clinical significance of the studyThe results of this clinical trial provide that aPDT can be considered an adjunct method for root canal disinfection with the same effectiveness as passive ultrasonic irrigation.

Ultrasonic activation of adhesive systems increases bond strength and intratubular penetration of resin cement in root dentin subjected to radiation therapy.

This study aimed to evaluate the effect of ultrasonic activation of etch-and-rinse and self-etch adhesive systems on the bond strength of resin cement to irradiated root dentin. Eighty human maxillary anterior teeth were distributed into 8 groups (n = 10), according to the type of adhesive system used (etch-and-rinse and self-etch), the ultrasonic activation of the adhesive systems, and the dentin condition (irradiated or non-irradiated - 70Gy). Endodontic treatment was performed followed by fiberglass post-space preparation. After fiberglass posts' luting, the roots were transversely sectioned on dentin discs and submitted to the push-out bond strength test (0.5mm/min). The fractured specimens were analyzed under a stereomicroscope and Scanning Electron Microscope (SEM) for failure mode classification. One of the dentin discs was analyzed under SEM to evaluate the characteristics of the adhesive interface. Irradiated specimens had lower bond strength than non-irradiated specimens (P < 0.0001). Ultrasonic activation of both adhesive systems increased the bond strength of the resin cement to irradiated dentin (P < 0.0001). Radiotherapy significantly affected the failure mode in the middle (P = 0.024) and apical thirds (P = 0.032) (adhesive failure). Non-irradiated specimens had a more homogeneous adhesive interface. When ultrasonically activated, both adhesive systems showed a greater number of resinous tags, regardless of the dentin condition. Ultrasonic activation of adhesive systems is a feasible strategy to enhance fiberglass posts retention in oncological patients.

Study on high-efficiency sulfide removement using sulfate radical-based AOPs and its oxidation mechanism of refractory gold ore

Pyrite enclosure poses a significant challenge in refractory gold ore processing, inhibiting gold leaching. This study explores Sulfate Radical-based Advanced Oxidation Processes (SR-AOPs) as an effective alternative for pretreating such ores. The oxidation pretreatments were performed under heat and ultrasound activation methods, including heat and ultrasound, and the influences of pretreatment time, pH, ultrasound power, pretreatment temperature, and precursor (PDS) concentration were investigated. Both ultrasonic and heat activation effectively mitigate the negative impact of pyrite enclosure on gold leaching. Specifically, the gold leaching rate improved from 21.9 % to 46.1 % and 74.9 % with heat and ultrasound activation, respectively The and generated by PDS dominate the pyrite oxidation according to EPR and quenching tests. Meanwhile, the SR-AOPs treatment also promotes the interactions between pyrite enclosure and leaching agent, reducing the negative influences of pyrite. Kinetic studies indicated that the oxidation processes are different under heat and ultrasound activation. Heat activation is governed by an interfacial chemical reaction, with an activation energy of 25.57 kJ/mol. In contrast, ultrasound-induced cavitation and microjets remove the oxidation layer, disrupt the pyrite crystal structure, and expose encapsulated gold. These effects accelerate pyrite oxidation, shifting the kinetic control step from interfacial chemical reaction to internal diffusion, with a reduced activation energy of 35.06 kJ/mol.

Cisplatin‐coordinated copolythiophene for synergistic chemotherapy and sonodynamic therapy of tumor

AbstractSonodynamic therapy (SDT) is a novel cancer treatment type showing the advantages of high tissue penetration ability, non‐invasion, low systemic toxicity, and high selectivity. However, SDT depends on ultrasound (US) irradiation; once US is turned off, the sonosensitizer will stop producing reactive oxygen species (ROS). Moreover, most sonosensitizers generate oxygen‐dependent ROS, that is, singlet oxygen (1O2), significantly limiting the therapeutic effect of SDT in treating deep and hypoxic tumor. Therefore, combining SDT with other treatment modalities is essential. Here, we designed and synthesized a series of cisplatin‐coordinated copolythiophenes (CPT‐Pts), simultaneously generating 1O2, superoxide anion, and hydroxyl radicals for synergistic chemotherapy and SDT of tumor. The sonodynamic toxicity and cytotoxicity of CPT‐Pts were accurately regulated by tuning the monomer ratio of the polythiophene. This copolymerization strategy avoids the side effects originating from the high‐dose chemotherapy drug while making up for limiting SDT relying on ultrasonic activation, effectively inhibiting cancer cells and tumors.