The effect of virtual simulation technology applied to undergraduate teaching of periodontal probing.

INTRODUCTION: The rise of virtual simulation technology and dental simulators has created a new pedagogical approach for undergraduate medical education. The purpose of this study is to evaluate the effect of virtual simulation (VS) technology on improving the students' comprehensive abilities in periodontal probing teaching in pre-practicum periodontology, such as increasing the accuracy of probing, tactile perception and performance on force control. MATERIALS AND METHODS: Twenty students were randomly selected among the fourth-year students and equally divided into VS technology teaching group (VS group) and traditional teaching group (TT group) by drawing half lots. One day later, students were required to probe the periodontal pathology model. The consistency rate between PD measurements and PD reference values, time consumption and final exam scores were recorded and statistically analysed using an unpaired Student's t test and p < .05 was considered statistical significance. Finally, questionnaires relating to teaching methods evaluation and the fidelity of the digital VS training system were distributed to students and teachers. RESULTS: VS group had a significantly higher consistency rate (72.976 ± 6.811%) than TT group (64.107 ± 4.988%, p = .004). To specify, the difference of consistency rates between the two groups in posterior teeth was larger than anterior teeth. Similarly, a larger difference was also found in proximal surfaces compared with buccal-lingual surfaces. As the pocket depth increased, the difference between the two groups increased too. These results indicated that VS is more efficient in complicated parts of periodontal probing teaching. In addition, students in VS group spent less time and gained a higher score than TT group (p < .05). The overall satisfaction rating in VS group was significantly higher than TT group. Lastly, teachers gave significant lower scores than students concerning the fidelity of VS system. CONCLUSION: Although there are much to improve, VS technology has obvious advantages in periodontal probing teaching in pre-practicum periodontology.

Liver Metabolic Dysregulation Induced by Polypropylene Nano- and Microplastics in Nile Tilapia Using Internal Extractive Electrospray Ionization Mass Spectrometry.

Understanding the metabolic disorders induced by nano- and microplastics in aquatic organisms at the molecular level could help us understand the potential toxicity of nano- and microplastics more thoroughly and provide a fundamental scientific basis for regulating the usage and management of plastic products. In this research, the effect of polypropylene nanoplastics (PP-NPs) and microplastics (PP-MPs) on metabolites in the tilapia liver was comprehensively investigated by internal extractive electrospray ionization mass spectrometry (iEESI-MS). A partial least-squares discriminant analysis (PLS-DA) and a one-component analysis of variance (ANOVA) were used for selecting 46 differential metabolites, including phospholipids, amino acids, peptides, carbohydrates, alkaloids, purines, pyrimidines, and nucleosides. Pathway enrichment analysis showed significant effects on glycerophospholipid metabolism, arginine and proline metabolism, and aminoacyl-tRNA biosynthesis after tilapia were exposed to PP-N/MPs. Dysregulation of these metabolites is mainly reflected in the possible induction of hepatitis, oxidative stress, and other symptoms. The application of iEESI-MS technology without sample pretreatment to the study of metabolic disorders in aquatic organisms under the interference of nano- and microplastics provides a promising analytical method for environmental toxicology research.

Phase II trial of docetaxel, bevacizumab, lenalidomide and prednisone in patients with metastatic castration-resistant prostate cancer.

OBJECTIVE: To determine the safety and clinical efficacy of two anti-angiogenic agents, bevacizumab and lenalidomide, with docetaxel and prednisone. PATIENTS AND METHODS: Eligible patients with metastatic castration-resistant prostate cancer enrolled in this open-label, phase II study of lenalidomide with bevacizumab (15 mg/kg), docetaxel (75 mg/m(2) ) and prednisone (10 mg daily). Docetaxel and bevacizumab were administered on day 1 of a 3-week treatment cycle. To establish safety, lenalidomide dosing in this combination was escalated in a conventional 3 + 3 design (15, 20 and 25 mg daily for 2 weeks followed by 1 week off). Patients received supportive measures including prophylactic pegfilgrastim and enoxaparin. The primary endpoints were safety and clinical efficacy. RESULTS: A total of 63 patients enrolled in this trial. Toxicities were manageable with most common adverse events (AEs) being haematological, and were ascertained by weekly blood counts. Twenty-nine patients (46%) had grade 4 neutropenia, 20 (32%) had grade 3 anaemia and seven (11%) had grade 3 thrombocytopenia. Despite frequent neutropenia, serious infections were rare. Other common non-haematological grade 3 AEs included fatigue (10%) and diarrhoea (10%). Grade 2 AEs in >10% of patients included anorexia, weight loss, constipation, osteonecrosis of the jaw, rash and dyspnoea. Of 61 evaluable patients, 57 (93%), 55 (90%) and 33 (54%) had PSA declines of >30, >50 and >90%, respectively. Of the 29 evaluable patients, 24 (86%) had a confirmed radiographic partial response. The median times to progression and overall survival were 18.2 and 24.6 months, respectively. CONCLUSIONS: With appropriate supportive measures, combination angiogenesis inhibition can be safely administered and potentially provide clinical benefit. These hypothesis-generating data would require randomized trials to confirm the findings.

CircFgfr2 promotes osteogenic differentiation of rat dental follicle cells by targeting the miR-133a-3p/DLX3 signaling pathway.

Dental follicle cells (DFCs) promote bone regeneration in vivo and in vitro. Circular RNAs (circRNAs) play crucial roles in bone development and regeneration. Our previous study demonstrated the upregulation of circFgfr2 expression during the osteogenic differentiation of DFCs. However, the molecular mechanisms and functional roles of circFgfr2 in DFCs osteogenesis remain unclear. In this study, we aimed to investigate the subcellular localization of circFgfr2 in DFCs using fluorescence in situ hybridization. In vitro investigations demonstrated that circFgfr2 overexpression promoted osteogenic differentiation, as evidenced by real-time quantitative polymerase chain reaction. By integrating the outcomes of bioinformatics analyses, dual luciferase reporter experiments, and chromatin isolation by RNA purification, we identified circFgfr2 as a sponge for miR-133a-3p, a key regulator of osteogenic differentiation. Moreover, miR-133a-3p suppressed osteogenic differentiation by targeting DLX3 and RUNX2 in DFCs. We validated that circFgfr2 promoted the osteogenic differentiation of DFCs through the miR-133a-3p/DLX3 axis. To further investigate the therapeutic potential of circFgfr2 in bone regeneration, we conducted in vivo experiments and histological analyses. Overall, these results confirmed the crucial role of circFgfr2 in promoting osteogenesis. In summary, our findings demonstrated that the circFgfr2/miR-133a-3p/DLX3 pathway acts as a cascade, thereby identifying circFgfr2 as a promising molecular target for bone tissue engineering.

Facile and green synthesis of chlorophyll-derived multi-color fluorescent carbonized polymer dots and their use for sensitive detection of hemin.

Due to the very important role in physiological process, a simple and sensitive hemin detection method is necessarily required. Biomass-based carbonized polymer dots (CPDs) have been widely studied especially as fluorescence probe owing to the advantages of low toxicity and the variety of fluorescence color, yet there are still challenges in developing their multi-color emission property from the same raw materials. In this work, red, white and blue emissive CPDs derived from chlorophyll have been synthesized via hydrothermal method. Then white-emitted CPDs (white-CPDs) with the Commission International d'Eclairage (CIE) coordinates at (0.34, 0.32) were used to develop a fluorescence quenched sensing system for hemin determination. There is a good linear relationship between (F0-F)/F0 and concentration of hemin in the range of 0.1-0.95 µM with a detection limit of 0.043 µM, and the quenching mechanism was considered to be caused by inner filter effect (IFE). Moreover, it has been successfully used for hemin detection in serum and also for visual determination, which indicating great potential in applications of disease diagnoses and trace identification.

Multisensory Preclinical Training Strategy of Periodontal Scaling for Undergraduates.

BACKGROUND: Invisibility of subgingival scaling is the most important negative factor affecting the performance of periodontal treatment. A multisensory teaching strategy is used in the preclinical training of undergraduates in order to increase the haptic-auditory-visual feedback, aiming to overcome the invisibility and achieve minimal postoperative complications, improving patients' treatment experience. METHODS: One hundred undergraduate dental students in grade 5 were divided into a multisensory teaching strategy group (MTS: n = 50) and a conventional training pattern group (CTP: n = 50). All participants attended a lecture on using an ultrasonic subgingival scaler (USS) and Gracey curettes (GRA), followed by a 3-week training programme. Students in the MTS group were trained in a haptic/auditory-visual feedback manner, whereas students in the CTP group were trained conventionally. After the training phase, paired students in the 2 different groups performed subgingival scaling in paired patients with equivalent teeth of periodontitis using USS and GRA. Objective and subjective postoperative evaluations were recorded. Probing depth (PD) and gingival index (GI) were evaluated before and 4 weeks after scaling by the same periodontal specialist. RESULTS: MTS significantly reduced treatment time and ameliorated postoperative complications (gingival injury, haemorrhage and root surface roughness; P < .05). Postoperative sensitivity was reduced in the MTS group from day 1 to day 7 (D1-D5: P < .001; D6: P = .002; D7: P = .003), whereas postoperative pain was reduced on day 1 (P = .006), compared with that in the CTP group. The PD reduction was not significant between the groups (MTS: 3.17 ± 0.95 mm vs CTP: 3.07 ± 0.97 mm, P > .05), whereas the GI change showed a significant difference between the groups (MTS: 1.71 ± 0.41 vs CTP: 1.67 ± 0.41, P < .05). CONCLUSIONS: Multisensory teaching strategies in the preclinical periodontal training of undergraduates can reduce postoperative complications (gingival injury, postoperative haemorrhage, and root surface roughness) and provide a better treatment experience (decreased treatment time and postoperative pain and sensitivity) for patients.

Topographic Cues of a PLGA Scaffold Promote Odontogenic Differentiation of Dental Pulp Stem Cells through the YAP/ß-Catenin Signaling Axis.

PURPOSE: The underlying mechanism of how topographic cues of artificial scaffolds regulate cell function remains poorly understood. Yes-associated protein (YAP) and ß-catenin signaling have both been reported to play important roles in mechano-transduction and dental pulp stem cells (DPSCs) differentiation. We investigated the effects of YAP and ß-catenin in spontaneous odontogenic differentiation of DPSCs induced by topographic cues of a poly(lactic-co-glycolic acid) (PLGA) membrane. METHODS: The topographic cues and function of a fabricated PLGA scaffold were explored via scanning electron microscopy (SEM), alizarin red staining (ARS), reverse transcription-polymerase chain reaction (RT-PCR), and pulp capping. Immunohistochemistry (IF), RT-PCR, and western blotting (WB) were used to observe the activation of YAP and ß-catenin when DPSCs were cultured on the scaffolds. Further, YAP was inhibited or overexpressed on either side of the PLGA membrane, and YAP, ß-catenin, and odontogenic marker expression were analyzed using IF, ARS, and WB. RESULTS: The closed side of the PLGA scaffold promoted spontaneous odontogenic differentiation and nuclear translocation of YAP and ß-catenin in vitro and in vivo compared to the open side. The YAP antagonist verteporfin inhibited ß-catenin expression, nuclear translocation, and odontogenic differentiation on the closed side, but the effects were rescued by LiCl. YAP overexpressing DPSCs on the open side activated ß-catenin signaling and promoted odontogenic differentiation. CONCLUSION: The topographic cue of our PLGA scaffold promotes odontogenic differentiation of DPSCs and pulp tissue through the YAP/ß-catenin signaling axis.

Evaluation of Copper Levels in Dental Calculus of OSF Patients with Chewing Dried Areca-Nut Quids in Hunan Province of Mainland China.

Dental calculus is a potential material that can be used for assessing chronic exposure to trace heavy metals in oral cavity as it is a long-term reservoir. The aim of this study was to investigate the correlation between dental calculus copper levels and risk of oral submucous fibrosis (OSF) due to chewing dried areca-nut quids in Mainland China. This study included 34 OSF (grade 1) sufferers with dried areca-nut quids chewing as the patient group and 23 healthy individuals without areca-nut chewing as the control group. The dental calculus sample was obtained from all 57 participants and evaluated by inductively coupled plasma mass spectrometry (ICP-MS) for dental calculus level of copper. This work revealed that the mean copper level of dental calculus was significantly higher in OSF (grade 1) sufferers with areca-nut chewing than those in healthy individuals without areca-nut chewing (p < 0.001). This work provided an evidence to support that there may be a positive correlation between elevated levels of copper in dental calculus caused by chewing dried areca-nut quids and an increased risk of developing OSF in Mainland China.

Effect of sodium fluoride, ampicillin, and chlorhexidine on Streptococcus mutans biofilm detachment.

We examined the effect of three clinically used antimicrobials on Streptococcus mutans UA159 biofilm detachment under flow conditions. Sodium fluoride (NaF) and chlorhexidine at MIC levels promoted biofilm detachment and inhibited detachment when concentrations were higher than the MIC and reduced detached-cell viability only at high concentrations. Ampicillin at all concentrations tested inhibited detachment and reduced the percentage of viable biofilm-detached cells. All the three antimicrobial treatments reduced biofilm live/dead cell ratios.

Wnt/ß-catenin signaling participates in cementoblast/osteoblast differentiation of dental follicle cells.

Dental follicle cells (DFCs) are reported to contain stem cells. The canonical Wnt signaling pathway plays an important role in stem cell self-renewal and tooth development through ß-catenin expression. The objective of this study was to investigate whether Wnt/ß-catenin signaling pathway participates in the cementoblast/osteoblast differentiation of rat DFCs. Immunohistochemistry was used to compare the expression of ß-catenin in rat mandibular first molars from postnatal days 1-13. The effects of Wnt/ß-catenin signaling on DFCs in vitro were examined by lithium chloride (LiCl) treatment by immunofluorescence, cell counting, dual-luciferase reporter assays, western blotting, and alkaline phosphatase activity analysis. ß-Catenin expression was absent in the dental follicles on days 1 and 3 in vivo. It then progressively increased from days 5 to 13. In vitro studies of the DFCs showed that LiCl stimulation caused ß-catenin, which was mainly located in the cell membrane and cytoplasm of DFCs, to be immediately transferred to the nucleus and led to the inhibition of proliferation at 12 and 24 hr. LiCl treatment also downregulated the levels of phosphorylated-ß-catenin, while upregulating the levels of total ß-catenin, nuclear ß-catenin, osteocalcin, runt-related transcription factor 2, and collagen type I. In addition, LiCl enhanced the ß-catenin/T-cell factor luciferase activity and alkaline phosphatase activity. These results suggest that Wnt/ß-catenin signaling pathway positively regulates the cementoblast/osteoblast differentiation of the DFCs.

Reverse effects of Streptococcus mutans physiological states on neutrophil extracellular traps formation as a strategy to escape neutrophil killing.

Bacteria in nature are present in different lifestyles with distinct characteristics. Streptococcus mutans is the etiologic pathogen of dental caries and could easily gain access into the bloodstream after oral surgery and adopt a biofilm lifestyle, resulting in infective endocarditis. A growing amount of evidence have revealed that the large web-like structure composed of extracellular DNA and antimicrobial proteins released by neutrophils, named Neutrophil Extracellular Traps (NETs), play an active role in the defense against bacterial invasion. The present study demonstrated that NETs formation was discriminatively affected by S. mutans biofilm and its planktonic counterpart. The free-floating planktonic S. mutans exhibited an active NETs response, whereas the biofilm community exhibited a reverse negative NETs response. Besides, impaired biofilm killing correlated with the decrease in NETs production. Unlike planktonic cells, biofilm avoided the burst of reactive oxygen species (ROS) when co-culture with neutrophils, and the NADPH-oxidase pathway was partially involved. A mice infection model also supported the distinguishing response of neutrophils challenged by different lifestyles of S. mutans. In conclusion, different bacterial physiological states can affect the distinct response of the host-microbe interaction, thus contributing to the anti-pathogen immune response activation and immune surveillance survival.

A review of spectroscopic probes constructed from aptamer-binding gold/silver nanoparticles or their dimers in environmental pollutants' detection.

The issue of environmental pollutant residues has gained wide public attention all along. Therefore, it is necessary to develop simple, rapid, economical, portable, and sensitive detection techniques, which have become the focus of research in the pollutants detection field. Spectroscopy is one of the most convenient, simple, rapid, and intuitive analytical tools that can provide accurate information, such as ultraviolet spectroscopy, fluorescence spectroscopy, Raman spectroscopy, plasmon resonance spectroscopy, etc. Gold nanoparticles, silver nanoparticles, and their dimers with unique optical properties are commonly used in the construction of spectroscopic probes. As a class of oligonucleotides that can recognize specific target molecules, aptamers also have a strong ability to recognize small-molecule pollutants. The application of aptamer-binding metal nanoparticles in biosensing detection presents significant advantages for instance high sensitivity, good selectivity, and rapid analysis. And many spectroscopic probes constructed by aptamer-binding gold nanoparticles, silver nanoparticles, or their dimers have been successfully demonstrated for detecting pollutants. This review summarizes the progress, advantages, and disadvantages of aptamer sensing techniques constructed by visual colorimetric, fluorescence, Raman, and plasmon resonance spectroscopic probes combining gold/silver nanoparticles or their dimers in the field of pollutants detection, and discusses the prospects and challenges for their future.

Facile Hydrothermal Synthesis of Chlorella-Derived Environmentally Friendly Fluorescent Carbon Dots for Differentiation of Living and Dead Chlorella.

The judgment of microalgae viability is a vital procedure in the process of microalgae culture and treatment, which also plays an important role in bioremediation, bioindication, and pharmacology fields. The current conventional methods for defining living/dead microalgal cells are complicated or laborious. Hence, developing a simple and reliable detection method for microalgae viability is still challenging. Here, we developed chlorella-based carbonized polymer dots (c-CPDs) by a hydrothermal method. Due to their small average size of 5.0 nm, obvious excitation-dependent emission, stable fluorescence properties, and low toxicity, c-CPDs could be used for distinguishing living or dead chlorella by testing different fluorescence characteristics of c-CPD-labeled chlorella. Compared with conventional cellular dyes used for differentiating living/dead microalgae, c-CPDs significantly reduced toxicity, showing good sensitivity and reliability. This work provided a method to prepare environmentally friendly carbon dots (CDs) using microalgae, which had potential to be prepared on a large scale and might be applied feasibly in the preparation of doped CDs by controlling the growth of chlorella.

Higher incidence of Osteonecrosis of the Jaw (ONJ) in patients with metastatic castration resistant prostate cancer treated with anti-angiogenic agents.

ONJ is an important toxicity in cancer patients receiving bisphosphonate therapy. Here we report a higher than usual incidence of ONJ, 11 of 60 (18.3%, 95% Confidence Interval, CI: 9%-28%) patients enrolled in a phase II clinical trial combining bevacizumab, docetaxel, thalidomide, and prednisone (ATTP) in chemotherapy-naive men with metastatic castration resistant prostate cancer (mCRPC). The use of bisphosphonates was allowed at study entry. Our study suggests that anti-angiogenic and chemotherapy agents can predispose to the development of ONJ in men with mCRPC on zoledronic acid. Imaging modalities, such as bone scans, may be useful in following the clinical course of patients who develop ONJ.

Identification of an Efflux Transporter LmrB Regulating Stress Response and Extracellular Polysaccharide Synthesis in Streptococcus mutans.

Efflux transporters have been implicated in regulating bacterial virulence properties such as resistance to antibiotics, biofilm formation and colonization. The pathogenicity of Streptococcus mutans, the primary etiologic agent of human dental caries, relies on the bacterium's ability to form biofilms on tooth surface. However, the studies on efflux transporters in S. mutans are scare and the function of these transporters remained to be clarified. In this study, we identified an efflux transporter (LmrB) in S. mutans through cloning the lmrB gene into Escherichia coli. Introducing lmrB into E. coli conferred a multidrug-resistant phenotype and resulted in higher EtBr efflux activity which could be suppressed by efflux inhibitor. To explore whether LmrB was involved in S. mutans virulence properties regulation, we constructed the lmrB inactivation mutant and examined the phenotypes of the mutant. It was found that LmrB deficiency resulted in increased IPS storage and prolonged acid production. Enhanced biofilm formation characterized by increased extracellular polysaccharides (EPS) production and elevated resistance to hydrogen peroxide and antimicrobials were also observed in lmrB mutant. To gain a better understanding of the global role of LmrB, a transcriptome analysis was performed using lmrB mutant strain. The expression of 107 genes was up- or down-regulated in the lmrB mutant compared with the wild type. Notably, expression of genes in several genomic islands was differentially modulated, such as stress-related GroELS and scnRK, sugar metabolism associated glg operons and msmREFGK transporter. The results presented here indicate that LmrB plays a vital global role in the regulation of several important virulence properties in S. mutans.

Glucan HBP-A increase type II collagen expression of chondrocytes in vitro and tissue engineered cartilage in vivo.

OBJECTIVE: Although chondroprotective activities have been documented for polysaccharides, the potential target of different polysaccharide may differ. The study was aimed to explore the effect of glucan HBP-A in chondrocyte monolayer culture and chondrocytes-alginate hydrogel constructs in vivo, especially on the expression of type II collagen. METHODS: Chondrocytes isolated from rabbit articular cartilage were cultured and verified by immunocytochemical staining of type II collagen. Chondrocyte viability was assessed after being treated with HBP-A in different concentrations. Morphological status of chondrocytes-alginate hydrogel constructs in vitro was observed by scanning electron microscope (SEM). The constructs were treated with HBP-A and then injected to nude mice subcutaneously. Six weeks after transplantation, the specimens were observed through transmission electron microscopy (TEM). The mRNA expressions of disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTs-5), aggrecan and type II collagen in both monolayer culture and constructs were determined by real time polymerase chain reaction (PCR). The expression of type II collagen and matrix metalloproteinases-3 (MMP-3) in chondrocyte monolayer culture was also tested through Western blot and enzyme linked immunosorbent assay (ELISA), respectively. RESULTS: MMP-3 secretion and ADAMTs-5 mRNA expression in vitro were inhibited by HBP-A at 0.3 mg/mL concentration. In morphological study, there were significant appearance of collagen in those constructs treated by HBP-A. Accordingly, in both chondrocyte monolayer culture and chondrocytes-alginate hydrogel constructs, the expression of type II collagen was increased significantly in HBP-A group when compared with control group (P<0.001). CONCLUSIONS: The study documented that the potential pharmacological target of glucan HBP-A in chondrocytes monolayer culture and tissue engineered cartilage in vivo may be concerned with the inhibition of catabolic enzymes MMP-3, ADAMTs-5, and increasing of type II collagen expression.

Effects of intracanal irrigant MTAD Combined with nisin at sub-minimum inhibitory concentration levels on Enterococcus faecalis growth and the expression of pathogenic genes.

Exposure to antibiotics is considered to be the major driver in the selection of antibiotic-resistant bacteria and may induce diverse biological responses in bacteria. MTAD is a common intracanal irrigant, but its bactericidal activity remains to be improved. Previous studies have indicated that the antimicrobial peptide nisin can significantly improve the bactericidal activity of MTAD against Enterococcus faecalis. However, the effects of MTAD and its modification at sub-minimum inhibitory concentration (sub-MIC) levels on Enterococcus faecalis growth and the expression of pathogenic genes still need to be explored. In this study, the results of post-antibiotic effects (PAE) and post-antibiotic sub-MIC effects (PASME) showed that MTADN (nisin in combination with MTAD) had the best post-antibiotic effect. E. faecalis after challenge with MTAD was less sensitive to alkaline solutions compared with MTAN (nisin in place of doxycycline in MTAD) and MTADN. E. faecalis induced with sub-MIC of MTAD generated resistance to the higher concentration, but induction of E. faecalis with MTAN did not cause resistance to higher concentrations. Furthermore, real-time polymerase chain reaction (RT-PCR) showed that the stress caused by sub-MIC exposure to MTAD, MTAN, or MTADN resulted in up- or down-regulation of nine stress genes and four virulence-associated genes in E. faecalis and resulted in different stress states. These findings suggested that nisin improved the post-antibacterial effect of MTAD at sub-MIC levels and has considerable potential for use as a modification of MTAD.

Controlled fabrication of fluorescent barcode nanorods.

We report a novel technique for generating polymer fluorescent barcode nanorods by reactive ion etching of polymer multilayer films using nonclose-packed (ncp) colloidal microsphere arrays as masks. The fluorescent polymer multilayer films were spin-coated on a substrate, and ncp microsphere arrays were transferred onto these films. The exposed polymers were then etched away selectively, leaving color-encoded nanorods with well-preserved fluorescent properties. By modifying the spin-coating procedure, the amount of polymer in each layer could be tuned freely, which determined the relative fluorescence intensity of the barcode nanorods. These nanorod arrays can be detached from the substrate to form dispersions of coding materials. Moreover, the shape of the nanorods is controllable according to the different etching speeds of various materials, which also endows the nanorods with shape-encoded characters. This method offers opportunities for the fabrication of novel fluorescent barcodes which can be used for detecting and tracking applications.

[A new ultrasonic system in initial periodontal therapy: clinical efficacy and perception of pain].

OBJECTIVE: To compare the clinical efficacy and perception of pain during initial periodontal treatment using Vector-system and a conventional ultrasonic system. METHODS: Thirty-eight patients with mild to moderate periodontitis were debrided using both A-system (Vector-system) and B-system (Suprasson P5 Newtron) in a split mouth design. At baseline, one month after treatment, plaque index (PLI) and bleeding on probing (BOP) were recorded and probing depth(PD) was measured. A verbal analogue scale (VAS) was used to evaluate the perceived pain right after the treatment. RESULTS: At one month evaluation, all areas showed an improvement in clinical parameters. No statistically significant differences in PD and BOP could be observed between areas treated by two different systems, while A-system contributed to greater improvement in PLI than B-system. Patients treated with A-system [(22.5 +/- 7.5) mm] experienced about 60% the amount of pain compared with the conventional ultrasonic device [(37.2 +/- 11.3) mm]. CONCLUSIONS: During initial periodontal treatment for the patients with mild to moderate periodontitis, A-system could achieve a comparable clinical efficacy and reduced pain sensations to conventional ultrasonic device.