[Risk factors of perioperative hypertension in dental implant surgeries with bone augmentation].

OBJECTIVE: To investigate the characteristics and risk factors of perioperative hypertension during dental implant surgeries with bone augmentation. METHODS: A retrospective cohort study was conducted. Seven hundred and twenty-eight cases underwent dental implant placement and bone augmentation in Peking University School and Hospital of Stomatology from September 2021 to August 2022 were recruited in this study according to the inclusion and exclusion criteria. They were divided into different groups according to the exposure factors which were gender, age, surgical time, and surgical approach. The correlation between perioperative hypertension and the exposure factors was analyzed. RESULTS: The average systolic blood pressure variability was 9.93%±6.63% (maximum 50.41%), the average diastolic blood pressure variability was 12.45%±8.79% (maximum 68.75%), and the average mean arterial pressure variability was 10.02%±6.61% (maximum 49.48%). The incidence rate of perioperative hypertension was 26.77%. Male, age ≥ 60 years, and surgical time > 60 minutes were risk factors for perioperative hypertension (P < 0.05), and the relative risks (95%CI) were 1.74 (1.21-2.50), 2.35 (1.54-3.58), and 1.65 (1.15-2.38), respectively. There was no significant difference in the incidence of perioperative hypertension among the guided bone regeneration, sinus floor elevation with transalveolar approach, and sinus floor elevation with lateral window approach (P>0.05). However, the risk factors varied according to bone augmentation approaches. For the patients underwent guided bone rege-neration, the risk factors for perioperative hypertension included male, age ≥ 60 years, and surgical time > 60 minutes (P < 0.05). For the patients underwent maxillary sinus lift with transalveolar approach, the risk factor for perioperative hypertension was age ≥60 years (P < 0.05). For the patients underwent maxillary sinus lift with lateral window approach, male, age ≥60 years, and surgical time >60 minutes were not risk factors for perioperative hypertension (P>0.05). CONCLUSION: There was a certain risk of perioperative hypertension in oral implantation with bone augmentation. The influence of male, age ≥60 years and surgical time > 60 minutes on perioperative hypertension was related to the approach of bone augmentation.

Ring Repeating Unit: An Upgraded Structure Representation of Linear Condensation Polymers for Property Prediction.

Unique structure representation of polymers plays a crucial role in developing models for polymer property prediction and polymer design by data-centric approaches. Currently, monomer and repeating unit (RU) approximations are widely used to represent polymer structures for generating feature descriptors in the modeling of quantitative structure-property relationships (QSPR). However, such conventional structure representations may not uniquely approximate heterochain polymers due to the diversity of monomer combinations and the potential multi-RUs. In this study, the so-called ring repeating unit (RRU) method that can uniquely represent polymers with a broad range of structure diversity is proposed for the first time. As a proof of concept, an RRU-based QSPR model was developed to predict the associated glass transition temperature (Tg) of polyimides (PIs) with deterministic values. Comprehensive model validations including external, internal, and Y-random validations were performed. Also, an RU-based QSPR model developed based on the same large database of 1321 PIs provides nonunique prediction results, which further prove the necessity of RRU-based structure representation. Promising results obtained by the application of the RRU-based model confirm that the as-developed RRU method provides an effective representation that accurately captures the sequence of repeat units and thus realizes reliable polymer property prediction by data-driven approaches.

Health services provision of 48 public tertiary dental hospitals during the COVID-19 epidemic in China.

OBJECTIVES: To assess the status of health services provision of public tertiary dental hospitals during the COVID-19 epidemic in China and to evaluate the regional difference of telehealth. MATERIALS AND METHODS: The health services provision of public tertiary dental hospitals in China mainland during the COVID-19 epidemic was inquired. The status of non-emergency dental services, emergency dental services, and online professional consultation and the hospitals' geographical distribution were recorded and analyzed. RESULTS: All the 48 public tertiary dental hospitals suspended general non-emergency dental treatment while providing emergency dental services only. Ninety percent of them notified the change of dental services online, and 69% of them offered free online professional consultations. The penetration rate of online technology was significantly higher in the eastern region than that of the central and western regions. CONCLUSIONS: There was a significant change in the health service provision of Chinese public tertiary dental hospitals during the COVID-19 epidemic and wider use of telehealth in the eastern region. CLINICAL RELEVANCE: This report demonstrated that dental health services were significantly affected by the COVID-19 epidemic in China, which might lead to a long-time impact on dental care in the future.

Diet and lifestyle habits associated with caries in deciduous teeth among 3- to 5-year-old preschool children in Jiangxi province, China.

BACKGROUND: The purpose of this study was to investigate the status of caries in deciduous teeth and the effect of diet and lifestyle habits on dental caries among 3- to 5-year-old preschool children in Jiangxi Province, China. METHODS: In total, 2880 cases involving preschool children were selected by stratified cluster sampling. The dental examination methods and criteria followed the WHO guidelines. SPSS 19.0 was used for the statistical analysis. Chi square tests were used to compare the caries prevalence among children with different social characteristics. Non-parametric tests were used to compare the decayed, missing and filled teeth (dmft) index values. Univariate and multivariate regression analyses were used to study the effect of diet and lifestyle habits on dental caries. RESULTS: The caries prevalence among the 2880 cases of 3- to 5-year-old preschool children in Jiangxi Province, China was 49.13%. There was no gender difference in this rate (P > 0.05). The caries prevalence increased with age (P < 0.05). The prevalence of caries in the rural areas was higher than that in the urban areas (P < 0.05). The deciduous central incisors and deciduous molars had a higher caries prevalence than the other deciduous teeth. According to the multivariate logistic regression analysis, the caries risk increased with living in a rural area, exclusive breastfeeding, greater frequency of daily snacking, high frequency of snacking before sleep and beginning to brush teeth at a late age; the caries risk decreased when parents helped their children brush their teeth. CONCLUSION: The caries prevalence among 3- to 5-year-old preschool children in Jiangxi was lower than the level throughout the country and lower than the rate in other developing countries. The children's diet and lifestyle habits were closely related to dental caries. Parents and children should be more aware of oral health, and parents should help their children develop healthy lifestyle behaviours.

The impact of dissolved organic matter on the photodegradation of tetracycline in the presence of microplastics.

Microplastics (MPs), an emerging class of pollutants, significantly impact the photoconversion dynamics of tetracycline (TC). But the effect of prevalent dissolved organic matter (DOM) on TC photodegradation in the presence of MPs remains a gap in current research. In this study, the photoconversion behavior and mechanism of TC under simulated sunlight conditions were systematically investigated, both in the presence of DOM and in combination with polystyrene (PS) MPs. The results demonstrated that both DOM and MPs enhanced the photodegradation of TC when compared to its direct degradation. However, DOM, particularly humic acid (HA, 10 mg/L), exhibited a more pronounced enhancing effect on TC photodegradation within 1 h reaction, regardless of the presence or absence of MPs, reaching up to 80%. In reaction systems involving TC-HA and TC-HA-PS, the primary contributors to TC degradation were direct photolysis and HA photosensitization (free radical reactions). Conversely, photosensitization effects were not significant in the presence of fulvic acid (FA). Furthermore, even under dark reaction conditions, HA exhibited a 10% degradation effect on TC. Quenching experiments and electron spin resonance (ESR) results indicate that dark reaction processes involve free radical reactions. Additionally, toxicity test results showed a reduction in the acute toxicity of TC photodegradation products, yet the long-term cumulative risks to organisms deserved attention. In general, this investigation significantly advances our understanding of the intricate photoconversion behavior of TC in the presence of coexisting chemical components.

[Preparation, characterization and Calu-3 cellular uptake of three kinds of poly(b-benzyl-L-amino)block-poly(ethylene glycol) nanoparticles].

The aim of this paper is to compare the cytotoxicity and cellular uptake efficiency of three kinds of poly(b-benzyl-L-amino) block-poly(ethylene glycol) nanoparticles (PXA-PEG-NPs) using Calu-3 cells, and select one as a nasal drug delivery vector for curcumin (Cur). Poly(gamma-benzyl-L-glutamate) block-poly(ethylene glycol) nanoparticles (PBLG-PEG-NPs), poly(gamma-benzyl-L-lysine) block-poly(ethyleneglycol) nanoparticles (PZLL-PEG-NPs) and poly(gamma-benzyl-L-aspartate) block-poly(ethylene glycol) nanoparticles (PBLA-PEG-NPs) were prepared by emulsion-solvent evaporation method. MTT assays were used to evaluate the cytotoxicity of PXA-PEG-NPs against Calu-3 cells. The cellular uptake of nanoparticles was visualized by an inverted fluorescence microscope and quantified by a flow cytometer. The results indicated that even at high concentration of 2 mg x mL(-1) the three nanoparticles had no cytotoxicity on Calu-3 cells. Compared to the curcumin solution, the three curcumin-loaded PXA-PEG-NPs showed significantly higher cellular uptake efficiency on Calu-3 cells (at equal concentration of curcumin with 5 microg x mL(-1) Cur solution), PBLG-PEG-NPs group was the highest. The cellular uptake increased with incubation time, and has positive correlation with nanoparticle concentration. In brief, PXA-PEG-NPs are conducive to delivery Cur into cells, and PBLG-PEG-NPs might be provided as a good nasal drug delivery carrier.

Effect of polystyrene microplastics on tetracycline photoconversion under simulated sunlight: Vital role of aged polystyrene.

Photoconversion of tetracycline (TC) has been widely reported. However, the effect of microplastics (MPs) on TC conversion kinetics and mechanism has rarely been discussed. In this study, we investigated the effect of (aged) MPs on TC degradation under simulated sunlight and elucidated the underlying mechanism. Our findings demonstrated that the physical and chemical properties of polystyrene (PS), such as particle size, surface groups, and morphology, were significantly altered after aging. Moreover, photoconversion efficiency of TC was suppressed with the spiking of aged PS, while virgin PS showed an opposite tendency. The photodegradation reaction for photosensitization of PS involved 1O2 and HO·. The light-screening effect of aged PS occupied predominance, weakening the direct UV-light absorption of TC and resulting in lower TC degradation efficiency. Additionally, triplet-excited state PS was generated after photon acceptance by aged PS, which could transfer energy to O2, leading to the production of 1O2. The toxicity test manifested that the direct impact of TC products on fathead minnow was ignorable, but long-term negative effects on growth deserved observation. This study enhances our understanding of the environmental fate of PS and TC under sunlight, and provides crucial reference information for better evaluating the potential risk of MPs and chemicals.

Lignocellulosic biomass derived N-doped and CoO-loaded carbocatalyst used as highly efficient peroxymonosulfate activator for ciprofloxacin degradation.

Burning lignocellulosic biomass wastes in an outdoor atmosphere has placed heavy burden on ecological environment and increased risk on human health. Converting solid agricultural wastes into functional materials is a research hotspot. In this study, N-doped and CoO-loaded carbocatalyst (CoO-N/BC) was successfully synthesized from the cotton stalk biomass via a simple synthesis process of impregnation and carbonization. Compared with cotton stalk biomass derived pristine biochar, the CoO-N/BC possessed a higher specific surface area (466.631 m2 g-1vs 286.684 m2 g-1) as well as a better catalytic performance in the activation of peroxymonosulfate (PMS) for CIP degradation. The superior catalytic efficiency was ascribed to the directional flow of electrons on the well-organized carbon network of CoO-N/BC, which accelerated electron migration and improved electron conduction ability. Based on the results of radical quenching experiment and electron paramagnetic resonance (EPR), both radical and non-radical process conjointly led to the stepwise decomposition of CIP, and singlet oxygen (1O2) mediated non-radical pathway was discovered to play a dominant role. Besides, the carbon-bridge mediated non-radical pathway was proved to accelerate this degradation process through the experiments of prolong the time of adding CIP at different time intervals. Nitrogen doped sites and CoO active sites as well as defects formed in sp2-hybridized carbon network were supposed to be the active sites for PMS. Furthermore, EIS and LSV were employed to confirm the electron transfer mediated non-radical process of reaction system. This work provides a modified strategy for the disposition of lignocellulosic biomass wastes and illuminates the underlying mechanism of heterogeneous catalysis by CoO-N/BC.

The impact of the COVID-19 epidemic on the utilization of emergency dental services.

BACKGROUND/PURPOSE: To assess how the current COVID-19 epidemic influenced peoples' utilization of emergency dental services in Beijing, China. METHODS: The first-visit patients seeking emergency dental services before or at the beginning of the COVID-19 epidemic were retrieved. Their demographic characteristics and the reasons for visiting were recorded and analyzed. RESULTS: There were 2,537 patients involved in this study. Thirty-eight percent fewer patients visited the dental urgency at the beginning of the COVID-19 epidemic than before. The distribution of dental problems has changed significantly. The proportion of dental and oral infection raised from 51.0% of pre-COVID-19 to 71.9% during COVID-19, and dental trauma decreased from 14.2% to 10.5%. Meanwhile, the non-urgency cases reduced to three-tenths of pre-COVID-19. CONCLUSION: Within the limitation of this study, the COVID-19 epidemic had a strong influence on the utilization of emergency dental services.

[Status and strategies of oral health service demand and medical treatment utilization among 3- to 5-year-old preschool children in Jiangxi province].

OBJECTIVE: This study aimed to investigate the oral health service needs and dental treatment among 3-year-old to 5-year-old preschool children in Jiangxi province and provide data to support the development of relevant oral health policies, enhance the oral health service utilization and visit rate, and optimize oral manpower and service resources. METHODS: A total of 2 880 preschool children were selected via stratified cluster sampling. Dental examination methods and criteria according to the fourth national oral health epidemiological survey were adopted. Excel 2007 and SPSS 19.0 softwares were used for statistics analysis. Chi-square test and logistic regression analysis were performed. RESULTS: The caries prevalence was 49.13% (1 415/2 880) among the 2 880 cases of 3-
year-old to 5-year-old preschool children in Jiangxi province, approximately 53.37% (1 537/2 880) of which possessed oral health service needs. The parents of younger children assessed the oral situation better in older age than in their younger years (P<0.05), which was better in urban children than in rural children (P<0.05). The visiting rate of all the respondents was 12.33% (355/2 880), while the visiting rate of children with oral diseases was 17.31% (266/1 537). The top three reasons why patients did not visit the dentist were as follows: children's teeth have no problem, the teeth damage in teeth was considerably minimal, and primary teeth would be replaced without the need for treatment. The influencing factors included lower visiting rate in females than in males (OR=0.499, 95%CI: 0.411-0.606) and lower visiting rates in rural areas than in urban areas (OR=0.428, 95%CI: 0.353-0.519). Subjects with poor oral health and high oral knowledge scores possessed high dental service visit rates. CONCLUSIONS: The prevalence of caries in 3-year-old to 5-year-old preschool children in Jiangxi province is at a lower level than that in the national level. The proportion of the population actively seeking medical services is low, and their main purpose of treatment is to treat rather than prevention. Oral health education should be strengthened, and it should be incorporated to the contents of the kindergarten teacher training program to improve residents' awareness regarding children's oral health.

[Evaluation of effects of fluoride varnish on prevention of first permanent molar caries].

PURPOSE: To compare fluoride varnish and fluoride foam's effectiveness of preventing first permanent molar caries, and discuss patients' acceptance of the 2 materials among pupil patients. METHODS: Six hundred pupils aged 6-8 years from 3 primary schools in Shanghai Yangpu District were randomly selected.The subjects were randomly divided into 3 groups, with 200 students having 800 teeth in each. Two of these groups were experimental groups that receive fluoride varnish (Group A) and fluoride foam (Group B) respectively, and the third group (group C) was control group.Pupils in group A and group B received 2.26% Toro fluoride fluoride varnish, 1.23% fluoride foam was applied to the first molars. In the next 2 years, all pupils received dental health education every half year. The pupils' conditions of first permanent molar caries were checked in the sixth, twelfth, eighteenth and twenty-fourth month since the study started. Statistical analysis was performed using SPSS 10.0 software package. RESULTS: After 6 months, there was no significant difference between the 3 groups (P>0.05), the rate of caries incidence in the experimental group B was significantly higher than group A during the observation period after 12 months (P<0.05). Caries incidence in both group A and B was lower than the control group, with significant difference (P<0.05). CONCLUSIONS: Both duraphat fluoride varnish and fluoride foam prove to be effective in caries prevention. Moreover, considering other factors such as safety, convenience and cost, fluoride protector will be an even better choice in practical use.

Smart Fiber Membrane for pH-Induced Oil/Water Separation.

Wastewater contaminated with oil or organic compounds poses threats to the environment and humans. Efficient separation of oil and water are highly desired yet still challenging. This paper reports the fabrication of a smart fiber membrane by depositing pH-responsive copolymer fibers on a stainless steel mesh through electrospinning. The cost-effective precursor material poly(methyl methacrylate)-block-poly(4-vinylpyridine) (PMMA-b-P4VP) was synthesized using copper(0)-mediated reversible-deactivation radical polymerization. The pH-responsive P4VP and the underwater oleophilic/hydrophilic PMMA confer the as-prepared membrane with switchable surface wettability toward water and oil. The three-dimensional network structure of the fibers considerably strengthens the oil/water wetting property of the membrane, which is highly desirable in the separation of oil and water mixtures. The as-prepared fiber membrane accomplishes gravity-driven pH-controllable oil/water separations. Oil selectively passes through the membrane, whereas water remains at the initial state; after the membrane is wetted with acidic water (pH 3), a reverse separation is realized. Both separations are highly efficient, and the membrane also exhibits switchable wettability after numerous cycles of the separation process. This cost-effective and easily mass-produced smart fiber membrane with excellent oil-fouling repellency has significant potential in practical applications, such as water purification and oil recovery.

[Application of hand-use ProTaper instruments in endodontic treatment of molar canals].

OBJECTIVE: To evaluate the application of hand-use ProTaper instruments in endodontic treatment of molar canals. METHODS: A total of 203 permanent molars were randomly divided into the experimental group (99 molars) and control group (104 molars) prepared by hand-use ProTaper instruments and standard stainless steel K-file, respectively. The molars in the two groups were obturated by cold lateral condensation technique. The root canal preparation and obturation were evaluated by radiograph, and the working time of preparation and post-operative emergencies were analyzed. RESULTS: The preparation time in the experimental group was obviously shorter than that in the control group (P<0.01). The rate of satisfactory effect was significantly higher in the experimental group than in the control group (P<0.01), and the rate of post-operative emergencies was significantly lower in the experimental group (P<0.01). CONCLUSION: The application of hand-use ProTaper instruments may improve the effect of root canal treatment of the molars and shorten the working time and reduce the post-operative emergencies.