Confocal laser scanning evaluation of the influence of ledges on root canal disinfection.

The aim was to analyse the influence of an apical ledge on root canal disinfection. Forty-four single-rooted teeth were micro-CT scanned and inoculated with Enterococcus faecalis. In Group S shaping was performed with ProTaper Next (PTN) up to X3 at working length (WL). In Group L an apical ledge was created with K-Files #40 and shaping completed up to PTN X3. NaOCl 5% and EDTA 10% irrigant solutions were alternated. Confocal laser scanning microscope (CLSM) and viability staining were used to analyse the proportions of dead (red) and live (green) bacteria and penetration ability inside dentinal tubules. Data were analysed with the Mann-Whitney test with Bonferroni correction (p < 0.05). In Group L the amount of red fluorescence resulted significantly lower, and penetration ability was decreased in the apical and middle portion (p < 0.05). The presence of an apical ledge may negatively influence the disinfection both in the apical and middle third.

Segmented fluorescence correlation spectroscopy (FCS) on a commercial laser scanning microscope.

Performing accurate Fluorescence Correlation Spectroscopy (FCS) measurements in cells can be challenging due to cellular motion or other intracellular processes. In this respect, it has recently been shown that analysis of FCS data in short temporal segments (segmented FCS) can be very useful to increase the accuracy of FCS measurements inside cells. Here, we demonstrate that segmented FCS can be performed on a commercial laser scanning microscope (LSM), even in the absence of the dedicated FCS module. We show how data can be acquired on a Leica SP8 confocal microscope and then exported and processed with a custom software in MATLAB. The software performs segmentation of the data to extract an average ACF and measure the diffusion coefficient in specific subcellular regions. First of all, we measure the diffusion of fluorophores of different size in solution, to show that good-quality ACFs can be obtained in a commercial LSM. Next, we validate the method by measuring the diffusion coefficient of GFP in the nucleus of HeLa cells, exploiting variations of the intensity to distinguish between nucleoplasm and nucleolus. As expected, the measured diffusion coefficient of GFP is slower in the nucleolus relative to nucleoplasm. Finally, we apply the method to HeLa cells expressing a PARP1 chromobody to measure the diffusion coefficient of PARP1 in different subcellular regions. We find that PARP1 diffusion is slower in the nucleolus compared to the nucleoplasm.

Postmortem chondrocyte viability in porcine articular cartilage: Influence of time, temperature, and burial under winter conditions.

The aim of the present study was to investigate the effects of time, temperature, and burial in a natural environment on the viability of chondrocytes in porcine femoral condyles using confocal laser scanning microscopy. Hind trotters from 10 pigs were buried or left unburied. Samples were collected daily and stained with a combination of vital dyes (calcein-AM and ethidium homodimer-1). The chondrocytes showed an intense staining corresponding to their vitality. In the first 3 days, viability decreased slowly and showed no statistical difference between buried and unburied samples. After the first 3 days, it decreased rapidly, with the viability of the buried samples being 66% on day 4, decreasing to 25% on day 8 and to 16% on day 10, while in the unburied samples it decreased to 43% on day 4, 13% on day 8 and 5% on day 10. Our results indicate a time, temperature, and burial dependent decrease in chondrocyte viability and suggest the use of chondrocyte viability as a marker for estimating PMI in both the natural environment and in animals, as well as its potential use in humans.

Analysis of the depth of penetration of an epoxy resin-based sealer following a final rinse of irrigants and use of activation systems: An in vitro study.

Objective: The objective of the study was to compare and evaluate the depth of penetration of an epoxy resin-based sealer following a final rinse of 17% ethylenediaminetetraacetic acid (EDTA) and 18% 1-hydroxyethylidene 1, 1-diphosphonate (HEDP), with diode laser and passive ultrasonic activation (PUI): an in vitro confocal laser scanning microscopy study. Materials and Methods: Fifty-two extracted human mandibular premolar teeth with single root and single canal were selected. They were disinfected in 0.1% thymol solution, cleaned of calculus and soft tissues, and stored in 0.1% thymol solution till use. All teeth were radiographed and selected as per the inclusion and exclusion criteria. The teeth were decoronated using a diamond disk under copious water spray to acquire a standardized root length of 14 mm. Working length was established by inserting a size 10-K file into each root canal until it is visible at the apical foramen and by subtracting 1 mm from the recorded length. Instrumentation of the root canal was done till master apical file size of F3 using ProTaper universal, rotary instruments. The canals were irrigated with 2 mL of 3% sodium hypochlorite between successive files. Teeth were randomly divided into four subgroups n = 12 according to the intervention. Passive ultrasonic irrigation and diode laser were used to activate the irrigants. Final irrigation was performed with distilled water. These specimens were examined using confocal laser scanning microscope (OLYMPUS FLUOVIEW FV 3000) for dentinal tubule penetration of the sealer. Two-way ANOVA test and Tukey's multiple post hoc test were used for statistical analysis. Results: Highly significant difference was seen between the groups with EDTA and HEDP, with HEDP demonstrating the highest penetration. Among the activation techniques used in this study, PUI showed the highest penetration of the sealer. The least penetration was seen with diode laser activation and EDTA. Conclusions: The irrigation activation techniques significantly influence the penetration of sealer into root dentinal tubules. When penetration of sealer with different irrigation techniques and irrigants was evaluated, significant greater level of sealer penetration was attained with PUI activation of HEDP.

Assessment of the Penetration of an Endodontic Sealer into Dentinal Tubules with Three Different Compaction Techniques Using Confocal Laser Scanning Microscopy.

Adequate root canal sealing is essential for the success of endodontic treatment. There are numerous techniques available; identifying simple and efficient techniques is important to provide good patient care. The purpose of the study was to compare the maximum penetration depth and the percentage of sealant penetration of an endodontic sealer into dentine tubules using cold lateral condensation, continuous wave, and hybrid techniques, and to contrast the effectiveness of two different tapered gutta-percha master cones (0.02 and 0.04). A sample of sixty single root teeth was used. Six experimental groups were formed from the three filling techniques and the two tapered master cones. Images were acquired using a confocal laser scanning microscope. In the apical root third, the penetration percentage was higher in the hybrid compared with the continuous wave technique. The results indicated a higher penetration depth of hybrid compared with cold lateral condensation in the middle and coronal thirds, and in the apical third, a higher penetration was identified in the hybrid group compared with the continuous wave group. No significant differences in penetration were found comparing 0.02 with 0.04 taper gutta-percha groups. The coronal cross-sections presented a higher penetration than the apical third sections. In conclusion, the hybrid technique a had higher maximum sealer penetration than the continuous wave in the apical third, and the coronal third hybrid and continuous wave had a higher penetration than cold lateral condensation.

In Situ Observation the Effect of Y on the Solidification Process of 7Mo-SASS under a Low Cooling Rate.

The effects of Y on the solidification process of 7Mo super austenitic stainless steel (7MoSASS) under low cooling rate conditions (10 °C/min) were investigated using high-temperature confocal laser scanning microscopy (HT-CLSM). The in situ observation results indicate that Y samples promote an increase in austenite nucleation density. After 10 s of nucleation, the nucleation density increased by 149.53/mm2 for the Y sample. Furthermore, variance analysis indicated that Y addition improved the uniformity of the 7MoSASS solidification microstructure under low cooling rate conditions. The Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory results showed that when the solid phase ratio was 0.5, the nucleation mode of the Y sample transitioned from saturation site nucleation to saturation site nucleation + Avrami nucleation. YAlO3 has a low lattice disregistry value with austenite, making it a suitable heterogeneous nucleation core for promoting the early nucleation of austenite. During the late stages of solidification, Y accumulates in the residual liquid phase, providing a greater degree of compositional undercooling. SEM-EDS analysis showed that Y contributed to the refinement of the 7MoSASS solidification microstructure, with the proportion of precipitated phases decreasing by approximately 7.5%. Cr and Mo were the main elements exhibiting positive segregation in 7MoSASS, and the Cr segregation ratio increased in the Y sample, while the Mo segregation ratio decreased.

Optical Measurement of the Stoichiometry of Thin-Film Compounds Synthetized From Multilayers: Example of Cu(In,Ga)Se2.

The properties of centimeter-sized thin-film compound semiconductors depend upon the morphology and chemical composition of the multiple submicrometer-thick elemental and alloy precursor layers from which they are synthesized. The challenge is to characterize the individual precursor layers over these length scales during a multistep synthesis without altering or contaminating them. Conventional electron and X-ray-based morphological and compositional techniques are invasive, require preparation, and are thus incompatible with in-line synthesis processes. In a proof-of-concept study, we applied confocal laser scanning microscopy (CLSM) as a noninvasive optical imaging technique, which measures three-dimensional surface profiles with nanoscale resolution, to this challenge. Using an array of microdots containing Cu(In,Ga)Se2 semiconductor layers for solar cells as an example, we performed CLSM correlative studies to quantify morphological and layer thickness changes during four stages of a thin-film compound synthesis. Using simple assumptions, we measured the micrometer-scale spatially resolved chemical composition of stacked precursor layers to predict the final material phases formed and predict relative device performance. The high spatial resolution, coupled with the ability to measure sizeable areas without influencing the synthesis at high speed, makes CLSM an excellent prospect for research and quality control tool for thin films.

Effects of DJK-5 and chlorhexidine on exopolysaccharide volume and pH in oral biofilms.

BACKGROUND: Exopolysaccharides (EPS) are essential constituents of the extracellular matrix within oral biofilms and are significantly influenced by the local microenvironment. This study aimed to investigate the impact of two distinct antimicrobial agents, DJK-5 and chlorhexidine (CHX), on the EPS volume and pH levels in oral biofilms. METHODS: Oral biofilms obtained from two donors were cultured on hydroxyapatite discs for durations of 3 days, 1 week, 2 weeks, 3 weeks, and 4 weeks. Subsequently, these biofilms were subjected to treatment with 10 µg/mL DJK-5 or 2% CHX for 3 min. The impact of these antimicrobial treatments on factors such as the proportion of dead bacterial, in situ pH, and EPS volume within the biofilms was assessed using corresponding fluorescent probes. The examination was carried out utilizing confocal laser scanning microscopy, and the resulting images were analyzed with a focus on the upper and lower layers of the biofilm, respectively. RESULTS: DJK-5 exhibited a more potent bactericidal effect compared to CHX across the 3-day to 4-week duration of the biofilm (P < 0.05). The biofilms were acidic, with the upper layer being less acidic than the lower layer (P < 0.05). Both antimicrobial agents increased the pH, but DJK-5 had a greater effect than CHX (P < 0.05). The volume of EPS was significantly lower in DJK-5 treated biofilms compared to that of CHX, regardless of age or layer (P < 0.05). CONCLUSION: DJK-5 exhibited superior effectiveness in reducing viable bacteria and EPS volume, as well as in raising extracellular pH, as compared to chlorhexidine.

Controlling the structure of spin-coated multilayer ethylcellulose/hydroxypropylcellulose films for drug release.

Porous phase-separated ethylcellulose/hydroxypropylcellulose (EC/HPC) films are used to control drug transport out of pharmaceutical pellets. Water-soluble HPC leaches out and forms a porous structure that controls the drug transport. Industrially, the pellets are coated using a fluidized bed spraying device, and a layered film exhibiting varying porosity and structure after leaching is obtained. A detailed understanding of the formation of the multilayered, phase-separated structure during production is lacking. Here, we have investigated multilayered EC/HPC films produced by sequential spin-coating, which was used to mimic the industrial process. The effects of EC/HPC ratio and spin speed on the multilayer film formation and structure were investigated using advanced microscopy techniques and image analysis. Cahn-Hilliard simulations were performed to analyze the mixing behavior. A gradient with larger structures close to the substrate surface and smaller structures close to the air surface was formed due to coarsening of the layers already coated during successive deposition cycles. The porosity of the multilayer film was found to vary with both EC/HPC ratio and spin speed. Simulation of the mixing behavior and in situ characterization of the structure evolution showed that the origin of the discontinuities and multilayer structure can be explained by the non-mixing of the layers.

Effective Detergency Determination for Single Polymeric Fibers Using Confocal Microscopy.

Detergency determination for single polymeric fibers is of significant importance to screening effective detergents for laundry, but remains challenging. Herein, we demonstrate a novel and effective method to quantify the detergency for single polymeric fibers using a confocal laser scanning microscope (CLSM). It was applied to visualize the oil-removing process of single polymeric fibers and thus assess the detergency of various detergents. Four typical surfactants were selected for comparison, and a compounded detergent containing multiple components (e.g., anionic and nonionic surfactants, enzymes) was demonstrated to be the most effective and powerful soil-removing detergent because more than 50% of oil on the cotton fiber could be easily removed. Moreover, the oil removal process of three kinds of fibers (i.e., cotton, viscose, and polyester) was imaged and monitored by confocal microscopy. It was found that the percentage of the detergency of a single polyester fiber exceeded 70%, which is much higher than that of cotton and viscose fibers (~50%), which may be due to its relatively smooth surface. Compared to traditional methods, the CLSM imaging method is more feasible and effective to determine the detergency of detergents for single polymeric fibers.

Antimicrobial efficacy of Kerr pulp canal sealer (EWT) in combination with 10% amoxicillin on Enterococcus faecalis: A confocal laser scanning microscopic study.

Background: Sealers with antimicrobial properties play an important role in endodontic therapy success especially against Enterococcus faecalis infection found in failed root canal therapy. Addition of antibiotic agents to endodontic sealers may show significant increase in their antibacterial properties both against anaerobic and aerobic microbes. The purpose of the present study was to evaluate antimicrobial efficacy of Kerr pulp canal sealer (EWT) in combination with 10% amoxicillin against E. faecalis and post-root canal treatment viability of Enterococcus faecalis on the first and seventh day. Methods: A total of 60 extracted human mandibular premolar teeth were decoronated after initial decontamination with 1% NaOCl. Root length standardized to 12 mm. Canal instrumentation was done using ProTaper Universal file system till size F2 using 5.25% NaOCl. It was then infected with a pure strain of E. faecalis for a period of four days. Obturation was done using plain sealer, (n=30) and sealer-antibiotic combination, (n=30). Half of the teeth were sectioned at 24 hours (S, SA) and other half were sectioned seven days after obturation (S7, SA7). All samples were stained with SYTO9 and propidium iodide for imaging under Confocal Laser Scanning microscope. Statistical analysis was performed with the statistical software SPSS v. 17.0 (SPSS for Windows; SPSS Inc, Chicago, IL). Data was analysed using One Way ANOVA and post hoc Tukey test to determine statistical significance with p value < 0.01 considered significant. Results: Statistically significant differences were observed in green to red ratio between group S (9.561976) and S7 (0.435418) (p < 0.01). There was no difference found between SA (mean of green to red ratio, (0.70431) and SA7 (mean of green to red ratio, 0.85184). Conclusions: Antibiotics added to the sealer effectively eradicated of E. faecalis 24 hours post-obturation. However, after seven days, plain sealer was as effective as sealer-antibiotic combination.

The Contribution of Various In Vitro Methodologies to Comprehending the Filling Ability of Root Canal Pastes in Primary Teeth.

A void-free obturation during root canal treatment on primary teeth is currently very difficult to attain. In this study, the pulpectomy filling abilities of Bio-C Pulpecto (Angelus, Basil, Londrina, Paraná, Brazil) and of zinc oxide eugenol, or "ZOE" (DenPro, Prevest, New York, NY, USA), were compared using several in vitro techniques. Therefore, 30 primary anterior teeth were used in the present in vitro study. Analysis of variance (ANOVA), including a multiple comparison procedure (Holm-Sidak method, Dunn's Method, or Tukey test), was used. On micro-CT, Bio-C Pulpecto exhibited higher void percentages than did ZOE (10.3 ± 3.8%, and 3.5 ± 1.3%), respectively (p < 0.05). With digital microscopy, higher total void percentages were found in the BC (13.2 ± 26.7%) group compared to the ZOE (2.7 ± 2.8%) group (p < 0.05). With the CLSM, mean tubular penetration depths were higher for Bio-C Pulpecto than for ZOE in all canal thirds (p < 0.05). SEM images demonstrated no tags into dentinal tubules in either group throughout the three thirds. Moreover, higher statistically significant flowability was found for Bio-C (2.657 ± 0.06 mm) compared to ZOE (1.8 ± 0.13 mm) (p < 0.05). The findings of this study indicate that neither ZOE nor Bio-C Pulpecto appears to meet the criteria for an ideal root canal filling paste for primary teeth. This study laid the groundwork for future research by determining how micro-CT, digital microscopy, SEM, and CLSM contribute to our understanding of the filling process of primary teeth. More thorough research on the mechanism of root canal obturation on primary teeth is required to achieve a long-term successful root canal therapy in young children.

Assay of Reactive Oxygen/Nitrogen Species (ROS/RNS) in Arabidopsis Peroxisomes Through Fluorescent Protein Containing a Type 1 Peroxisomal Targeting Signal (PTS1).

Plant peroxisomes have an active nitro-oxidative metabolism. However, the assay of reactive oxygen and nitrogen species (ROS/RNS) could be a challenge since the purification of peroxisomes is technically a high time-consuming approach that needs to be optimized for each tissue/organ (root, leaf, fruit) and plant species. Arabidopsis thaliana, as a model plant for biochemical and molecular studies, has become a useful tool to study the basic metabolism, including also that of ROS/RNS. The combination of specific fluorescent probes with Arabidopsis plants expressing a fluorescent protein containing a type 1 peroxisomal targeting signal (PTS1) is a powerful tool to address the profile of ROS/RNS in peroxisomes by confocal laser scanning microscope (CLSM). This chapter provides a detailed description to detect the content and distribution of ROS and RNS in Arabidopsis peroxisomes, together with a critical analysis of their potentialities and limitations, since these approaches require appropriate controls to corroborate the obtained data.

Integration of terpesomes loaded Levocetrizine dihydrochloride gel as a repurposed cure for Methicillin-Resistant Staphylococcus aureus (MRSA)-Induced skin infection; D-optimal optimization, ex-vivo, in-silico, and in-vivo studies.

The intention of this work is to assess the repurposed antimicrobial impact of Levocetirizine dihydrochloride (LVC), which is a well-known antihistaminic drug, in addition, to augment the antimicrobial effect by using terpene-enriched vesicles (TPs). To investigate how various parameters affect TPs aspects, TPs were made employing the ethanol-injection-method and optimized d-optimal design. The TPs were characterized based on their entrapment efficiency percentage (EE%), particle size (PS), polydispersity index (PDI), and zeta potential (ZP). The optimum TP was submitted to more examinations. The optimum TP (TP12) showed a spherical vesicle having an EE% of 66.39 ± 0.12%, PS of 243.3 ± 4.60 nm, PDI of 0.458 ± 0.003, and ZP of 24.2 ± 0.55 mV. The in-vitro release study results demonstrated that LVC is sustainedly liberated from the optimum TP compared to LVC-solution. The ex-vivo assessment showed that LVC was released in a more sustained manner from TPs-gel related to LVC solution, optimum TP, and LVC gel. Ex-vivo visualization by confocal laser scanning microscopy showed good deposition of the fluorescein-labeled TP. Further, the in-vitro anti-bacterial effect and biofilm inhibition and detachment assessment confirmed the potency of LVC against Methicillin-resistant-Staphylococcus-aureus (MRSA). The in-silico study demonstrated that the LVC has excellent stability with other ingredients combined with it in the TPs, further, it proved that LVC is a potential candidate for treating MRSA. In-vivo assessments revealed a good antimicrobial effect toward MRSA infection. Moreover, the histopathological evaluation confirmed the safety of using TPs-gel topically. In conclusion, MRSA-related skin infections may be treated using the LVC loaded TPs-gel as a promising system.

Effect of different activation methods on the intratubular penetration of CaOH2 paste: Ex-vivo analysis by confocal laser scanning microscopy.

The aim of this study was to evaluate the maximum penetration depth (MPD) and penetration area (PA) of CaOH2 paste agitated by different methods and to measure the pH after performing these methods. Fifty-five mandibular premolars were divided into control, GL and 4 experimental groups, GEC, GXP, GEDDY and GI (n = 11), where the paste was agitated with Easy Clean, XP-endo Finisher, EDDY and Irrisonic, respectively. The canals were instrumented and irrigated with NaOCl. The paste was manipulated with propylene glycol and rhodamine B dye. Root sections were examined using confocal laser scanning microscopy. There was no difference between groups regarding PA (p > 0.05). At 5 mm, MPD was greater in GEC than in GL or GEDDY, and greater in GI than in GL (p < 0.05). At 2 mm, MPD was greater in GEC than in the other groups (p < 0.05). In conclusion, both Easy Clean and Irrisonic promoted deeper paste penetration and were associated with higher pH levels.

Live Fluorescence Visualization of Cellulose and Pectin in Plant Cell Walls.

The plant cell wall comprises various types of macromolecules whose abundance and spatial distribution change dynamically and are crucial for plant architecture. High-resolution live cell imaging of plant cell wall components is, therefore, a powerful tool for plant cell biology and plant developmental biology. To acquire suitable data, the experimental setup for staining and imaging of non-fixed samples must be straightforward and avoid creating stress-induced artifacts. We present a detailed sample preparation and live image acquisition protocol for fluorescence visualization of cell wall components using commercially available probes and stains.

Teriparatide ameliorates articular cartilage degradation and aberrant subchondral bone remodeling in DMM mice.

Objective: Knee osteoarthritis (KOA) is a highly prevalent musculoskeletal disorder characterized by degeneration of cartilage and abnormal remodeling of subchondral bone (SCB). Teriparatide (PTH (1-34)) is an effective anabolic drug for osteoporosis (OP) and regulates osteoprotegerin (OPG)/receptor activator of nuclear factor ligand (RANKL)/RANK signaling, which also has a therapeutic effect on KOA by ameliorating cartilage degradation and inhibiting aberrant remodeling of SCB. However, the mechanisms of PTH (1-34) in treating KOA are still uncertain and remain to be explored. Therefore, we compared the effect of PTH (1-34) on the post-traumatic KOA mouse model to explore the potential therapeutic effect and mechanisms. Methods: In vivo study, eight-week-old male mice including wild-type (WT) (n â€‹= â€‹54) and OPG-/- (n â€‹= â€‹54) were investigated and compared. Post-traumatic KOA model was created by destabilization of medial meniscus (DMM). WT mice were randomly assigned into three groups: the sham group (WT-sham; n â€‹= â€‹18), the DMM group (WT-DMM; n â€‹= â€‹18), and the PTH (1-34)-treated group (WT-DMM â€‹+ â€‹PTH (1-34); n â€‹= â€‹18). Similarly, the OPG-/- mice were randomly allocated into three groups as well. The designed mice were executed at the 4th, 8th, and 12th weeks to evaluate KOA progression. To further explore the chondro-protective of PTH (1-34), the ATDC5 chondrocytes were stimulated with different concentrations of PTH (1-34) in vitro. Results: Compared with the WT-sham mice, significant wear of cartilage in terms of reduced cartilage thickness and glycosaminoglycan (GAG) loss was detected in the WT-DMM mice. PTH (1-34) exhibited cartilage-protective by alleviating wear, retaining the thickness and GAG contents. Moreover, the deterioration of the SCB was alleviated and the expression of PTH1R/OPG/RANKL/RANK were found to increase after PTH (1-34) treatment. Among the OPG-/- mice, the cartilage of the DMM mice displayed typical KOA change with higher OARSI score and thinner cartilage. The damage of the cartilage was alleviated but the abnormal remodeling of SCB didn't show any response to the PTH (1-34) treatment. Compared with the WT-DMM mice, the OPG-/--DMM mice caught more aggressive KOA with thinner cartilage, sever cartilage damage, and more abnormal remodeling of SCB. Moreover, both the damaged cartilage from the WT-DMM mice and the OPG-/--DMM mice were alleviated but only the deterioration of SCB in WT-DMM mice was alleviated after the administration of PTH (1-34). In vitro study, PTH (1-34) could promote the viability of chondrocytes, enhance the synthesis of extracellular matrix (ECM) (AGC, COLII, and SOX9) at the mRNA and protein level, but inhibit the secretion of inflammatory cytokines (TNF-α and IL-6). Conclusion: Both wear of the cartilage was alleviated and aberrant remodeling of the SCB was inhibited in the WT mice, but only the cartilage-protective effect was observed in the OPG-/- mice. PTH (1-34) exhibited chondro-protective effect by decelerating cartilage degeneration in vivo as well as by promoting the proliferation and enhancing ECM synthesis of chondrocytes in vitro. The current investigation implied that the rescue of the disturbed SCB is dependent on the regulation of OPG while the chondro-protective effect is independent of modulation of OPG, which provides proof for the treatment of KOA. The translational potential of this article: Systemic administration of PTH (1-34) could exert a therapeutic effect on both cartilage and SCB in different mechanisms to alleviate KOA progression, which might be a novel therapy for KOA.

Comparative evaluation of penetration of sealers in dentinal tubules using passive ultrasonic irrigation and Erbium: yttrium-aluminum-garnet laser - A confocal laser scanning microscope study.

Context: Smear layer clearance and sealer penetration into dentinal tubules play a crucial role in root canal treatment. Hence, efficient irrigation is a crucial component of the root canal debridement. This in vitro study's objective was to assess the effectiveness of passive ultrasonic activation and Erbium: yttrium-aluminum-garnet (Er: YAG) laser-activated irrigation on irrigation solution penetration and sealer penetration into dentinal tubules. Aims: The aim of this study was to evaluate and compare the dentinal tubule penetration of epoxy resin-based sealer and bioceramic sealer after ultrasonic agitation and Er: YAG laser activation of the irrigant. Settings and Design: This was an in vitro study. Materials and Methods: Extracted tooth samples (n = 42) into 06 groups (Group A-F) with 7 samples in each group. Postobturation transverse section was made and assessed under a confocal laser scanning microscope for the total dentinal tubule penetration area and recorded as the mean apical, middle, and coronal penetration. Statistical Analysis: One-way analysis of variance test, followed by post hoc was used. Results: The intergroup comparison showed that Group E and Group F have significantly more penetration as compared to the controls and ultrasonic irrigation, P < 0.001 and P < 0.01, respectively. Conclusions: Er: YAG laser with AH plus sealer has the highest penetration in all the sections of tooth, followed by CeraSeal sealer.

Micromorphology and analysis of dentin surfaces after preparation with Er:YAG laser and application of self-etch adhesive system with 10-MDP. A confocal laser scanning microscope study.

AIM: The purpose of this study was to analyze and compare the micromorphology of the hybrid layer and the dentinal surface when the dentin was prepared with an Er:YAG laser or burs, and to find if there was any difference if the time of application of the self-etching primer on the dentin prepared with an Er:YAG laser was doubled.

In vitro antibacterial effects of photodynamic therapy against Enterococcus faecalis in root canals of deciduous teeth.

OBJECTIVE: This study aimed at evaluating the in vitro antibacterial efficacy of photodynamic therapy (PDT) on planktonic E. faecalis and its biofilm in the root canal of infected deciduous teeth. METHODS: Forty root canals of maxillary deciduous anterior teeth were enlarged up to #35 K-file and inoculated with E. faecalis for 21 days. The root canals were randomly assigned into four groups (n = 10): The normal saline group (control), 1% NaClO group, PDT group, and the 1% NaClO + PDT group. Paper point samples were obtained at baseline (S1) and after treatment (S2). The colony-forming units (CFU) were counted, and the bacterial growth rate calculated. From each subgroup, 5 samples were randomly selected after treatment and a scanning laser confocal microscope (CLSM) used to determine the distribution of dead / living bacteria on the biofilm surface of each subgroup. A scanning electron microscope (SEM) was used to observe bacterial morphologies in the root canal walls of the remaining 5 samples in each subgroup. The Kruskal-Wallis test and Dunn test with boferroni adjustment were used to analyze the effect of the different treatment techniques on the E. faecalis in root canals. RESULTS: Compared to the saline group, PDT significantly reduced bacterial counts in the root canal (p < 0.05). The CFU counts were lowest (p < 0.05) in the 1% NaClO and in 1% NaClO + PDT groups. The rate of bacterial death on the surface of the biofilm in the PDT group was significantly increased after treatment (p < 0.05), and the rate of bacterial death was highest in 1%NaClO group and 1%NaClO + PDT group (p < 0.05). CONCLUSION: PDT has an antibacterial activity against E. faecalis in the root canal of deciduous teeth. Its activity against planktonic E. faecalis is better than the activity on the intact biofilm. The antibacterial activity of PDT on E. faecalis in root canals of deciduous teeth is lower compared to that of 1% NaClO.