BACKGROUND:Leukoplakia is a common adverse reaction to traditional orthodontic treatment.There are still some controversies about the difference between light-transmitting clear and fixed aligners in the periodontal health status,incidence of leukoplakia,saliva and related bacteria in patients undergoing orthodontic treatment.OBJECTIVE:To compare the effects of clear and fixed aligners on the smooth surface of orthodontic teeth using Universal Visual Scoring System.METHODS:A total of 80 patients admitted to Department of Orthodontics,Second Hospital of Hebei Medical University from January 2018 to December 2022 were selected and randomly divided into a control group(n=40)and an observation group(n=40)using a random number table method.The control group received orthodontic treatment with fixed aligners,and the observation group received orthodontic treatment with clear aligners.Before treatment and after 6,12,and 24 months of treatment,the labial or buccal sides of teeth 13,33,16,and 36 were selected for each patient as the research subjects,and the visual scoring system was used to evaluate the white spot lesions.RESULTS AND CONCLUSION:(1)Before treatment and after 6,12,and 24 months of treatment,there was no significant difference in the color of tooth white spots and the severity of caries between the two groups of patients(P＞0.05).(2)For tooth 13,after 12 months of treatment,the color grade and caries severity of white spots were both higher than before treatment(P＜0.05).For tooth 33,the color grade and caries severity after 12 months of treatment were both higher than before treatment(P＜0.05).The severity of caries after 12 months of treatment was higher than that after 6 months of treatment(P＜0.05).For tooth 16,the color grade of white spots and the severity of caries after 12 months of treatment were both higher than those after 6 months of treatment(P＜0.05).(3)Multi-level ordered multi-classification Logistic regression model analysis showed that the color and severity of white spots on different teeth had little correlation with the type of appliance and were greatly affected by the correction time factor.Among them,the color change and severity of the initial white spots on teeth 33 and 13 were statistically significant at 12 and 24 months of treatment.(4)It is not possible to conclude that there is a difference in the effect of fixed and clear aligners on the white spot lesions of smooth surfaces of the teeth,but an increase in the risk of dental caries with the increase in the duration of treatment can be detected.

BACKGROUND:Leonurine has many biological activities such as improving microcirculation,anti-oxidation,anti-apoptosis,scavenging free radicals,anti-inflammation,and anti-fibrosis,and can promote osteogenic differentiation of bone marrow mesenchymal stem cells,which has the potential to be applied in the treatment of periodontitis. OBJECTIVE:To explore the anti-inflammatory and osteogenic effects of leonurine loading into chitosan/sodium glycerophosphate/sodium alginate hydrogel. METHODS:(1)Chitosan/sodium glycerophosphate/sodium alginate hydrogel(blank hydrogel)and chitosan/sodium glycerophosphate/sodium alginate/leonurus alkali hydrogel were prepared respectively.RAW 264.7 and MC3T3-E1 cells were inoculated with the two kinds of hydrogel.The cytotoxicity of hydrogels was detected by CCK-8 assay and live/dead cell staining.(2)RAW 264.7 cells were cultured in five groups.The blank group was cultured for 24 hours routinely.The lipopolysaccharide group was treated with lipopolysaccharide.The simple hydrogel group was treated with lipopolysaccharide and blank hydrogel.The drug-loaded hydrogel group was treated with lipopolysaccharide and drug-loaded hydrogel.The inhibitor group was treated with lippolysaccharide,drug-loaded hydrogel,and PI3K inhibitor LY294002.24 hours later,mRNA expression of inflammation-related factors was detected by qRT-PCR.Western blot assay was utilized to detect the protein expression of inflammation-related factors and PI3K/AKT signaling pathway.(3)MC3T3-E1 cells were inoculated in four groups.The blank group was cultured without any material.The simple hydrogel group was treated with blank hydrogel.The drug-loaded hydrogel group was treated with drug-loaded hydrogel.The inhibitor group was treated with drug-loaded hydrogel and PI3K inhibitor LY294002 for 7 days.Alkaline phosphatase staining was performed.mRNA expression levels of osteogenic factors were detected by qRT-PCR.The protein expression levels of the PI3K/AKT signaling pathway were detected by western blot assay. RESULTS AND CONCLUSION:(1)The results of CCK-8 assay and live/dead cell staining showed that the two kinds of hydrogels had no cytotoxic effect and had good cytocompatibility.(2)Compared with the blank group,the mRNA and protein expression levels of interleukin 6,tumor necrosis factor α,and interleukin 1β were significantly increased(P<0.05),and the protein expression levels of p-AKT,p-PI3K,p-p65,and p-IκBα were significantly increased in the lipopolysaccharide group(P<0.05).Compared with lipopolysaccharide group,mRNA and protein expression levels of the above indexes were decreased in drug-loaded hydrogel group(P<0.05).Compared with the drug-loaded hydrogel group,the mRNA and protein expression levels of the above indexes were decreased in the inhibitor group(P<0.05).(3)The activity of alkaline phosphatase in drug-loaded hydrogel group was higher than that in the blank group,simple hydrogel group,and inhibitor group(P<0.05).Compared with blank group,the mRNA expression levels of alkaline phosphatase,Runx2,osteocalcin,and type I collagen were increased(P<0.05),and the protein expression levels of p-AKT and p-PI3K were increased in the simple hydrogel group(P<0.05).Compared with the simple hydrogel group,the mRNA and protein expression levels of the above indexes were increased in the drug-loaded hydrogel group(P<0.05).Compared with the drug-loaded hydrogel group,the mRNA and protein expression levels of the above indexes were decreased in the inhibitor group(P<0.05).(4)These findings conclude that chitosan/sodium glycerophosphate/sodium alginate/leonurine hydrogel has anti-inflammatory and osteogenic effects,which may be related to the regulation of PI3K/AKT signaling pathway.

BACKGROUND:Leukoplakia is a common adverse reaction to traditional orthodontic treatment.There are still some controversies about the difference between light-transmitting clear and fixed aligners in the periodontal health status,incidence of leukoplakia,saliva and related bacteria in patients undergoing orthodontic treatment.OBJECTIVE:To compare the effects of clear and fixed aligners on the smooth surface of orthodontic teeth using Universal Visual Scoring System.METHODS:A total of 80 patients admitted to Department of Orthodontics,Second Hospital of Hebei Medical University from January 2018 to December 2022 were selected and randomly divided into a control group(n=40)and an observation group(n=40)using a random number table method.The control group received orthodontic treatment with fixed aligners,and the observation group received orthodontic treatment with clear aligners.Before treatment and after 6,12,and 24 months of treatment,the labial or buccal sides of teeth 13,33,16,and 36 were selected for each patient as the research subjects,and the visual scoring system was used to evaluate the white spot lesions.RESULTS AND CONCLUSION:(1)Before treatment and after 6,12,and 24 months of treatment,there was no significant difference in the color of tooth white spots and the severity of caries between the two groups of patients(P＞0.05).(2)For tooth 13,after 12 months of treatment,the color grade and caries severity of white spots were both higher than before treatment(P＜0.05).For tooth 33,the color grade and caries severity after 12 months of treatment were both higher than before treatment(P＜0.05).The severity of caries after 12 months of treatment was higher than that after 6 months of treatment(P＜0.05).For tooth 16,the color grade of white spots and the severity of caries after 12 months of treatment were both higher than those after 6 months of treatment(P＜0.05).(3)Multi-level ordered multi-classification Logistic regression model analysis showed that the color and severity of white spots on different teeth had little correlation with the type of appliance and were greatly affected by the correction time factor.Among them,the color change and severity of the initial white spots on teeth 33 and 13 were statistically significant at 12 and 24 months of treatment.(4)It is not possible to conclude that there is a difference in the effect of fixed and clear aligners on the white spot lesions of smooth surfaces of the teeth,but an increase in the risk of dental caries with the increase in the duration of treatment can be detected.

Nitrogen source is one of the important factors that affect the microalgae growth and lipid accumulation. We studied the effects of various nitrogen sources (i.e. NaNO3, CO(NH2)2, NH4Cl and CH3COONH4) and amount on the growth density, lipid yield, and eicosapentaenoic acid (EPA) content of Nannochloropsis oculata by single factor experimental method. The results show that N. oculata preferred NH4+ as nitrogen source rather than NO3- and CO(NH2)2. NH4+ could promote the growth and lipid accumulation of N. oculata. With the increase of nitrogen concentration, the biomass and the content of polyunsaturated fatty acid (PUFA) increased, but the content of lipid decreased. CH3COONH4 was the most suitable for growth, accumulation of lipid and EPA of N. oculata among the four investigated nitrogen sources. The optimal concentration was 5.29 mmol/L.
Eicosapentaenoic Acid ; metabolism ; Lipids ; biosynthesis ; isolation & purification ; Microalgae ; growth & development ; metabolism ; Nitrogen ; analysis ; metabolism ; Stramenopiles ; growth & development ; metabolism