Objective:To assess the cytotoxicity of self-adhesive resin cement RelyXTM U200 on human periodontal ligament fibro-blasts(HPDLFs)under different light treatment modes.Methods:The self-adhesive resin cement RelyXTM U200 was cured by immediate light(A),intermittent light(B),delayed light(C)and no light(D)treatment respectively.The HPDLFs were cultured with the specimen extracts under different light modes.The proliferation ability and apoptosis level of the cells in the groups were detected by CCK-8 test and flow cytometry apoptosis test.SPSS 20.0 software was used to analyze the cytotoxicity of specimens to HPDLFs.Results:At 24 h after light treatment the cytoxicity(grade)of group A,B,C and D was 1,2,3 and 4,at 72 h 1,2,2 and 3,respectively.At 72 h,the apoptosis index(％)of the cells in A,B,C and D groups was 6.38％±0.94％,16.34％±1.67％,24.13％±1.43％and 38.34％±2.75％respecitvely.Conclusion:The cytotoxicity of self-adhesive resin cement is the greatest under no light treatment mode and the least under immediate light treatment mode.

Maxillary first molar teeth usually have 4 cusps,a few teeth have stuck cusps on the lingual side of the mesial tongue tip,while the presence of additional cusp on the buccal side of the mesial buccal tip is rarely reported,and it is even more rare for the cusp to connect with the dentin,cementum and pulp cavity of the main crown and fuse together to form C-shaped roots.A case of the buccal supernumerary cusp of the right maxillary first molar with C-shaped root canal was reported.

Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.

Objective To investigate the effect of iRoot BP Plus on the repair of dental pulp cavity during pulp injury in rats,and to explore the possible role of iRoot BP Plus in the process of damage repair.Methods Bilateral maxillary first molars of 60 8-week-old SD rats were treated with direct pulp capping after pulp opening.They were divided into iRoot BP Plus group(BP group)and control group.After histological processing,the damage of dental pulp tissue and the calcification of pulp cavities were observed by microCT and HE staining.mRNA was extracted from rat dental pulp tissue,and the expression of inflammation and mineralization genes were detected by real-time quantitatitive PCR.Results The results of this study showed that the dental pulp tissue had different degrees of calcification at 1,4 and 7 days after direct pulp capping.There was no significant difference between the BP group and the control group on the 1st day after the operation,but on the 4th and 7th day after the operation,a regular calcified bridge was formed at the pulp hole in the BP group,and more pulp tissue was retained in the pulp cavity.In the control group,a large area of irregular calcified tissue was formed below the pulp hole.HE staining results showed that the pulp tissue had a heavy inflammatory response,and a large number of inflammatory cells infiltrated near the pulp orifice on the first day after the operation.On the 4th and 7th days after the opera-tion,mineralized tissue began to form near the pulp orifice in the BP group,and healthier pulp tissue was retained in the pulp cavity.The gene levels of IL-1β and TNF-α in the BP group were lower than those in the control group,and the gene expression levels of min-eralization indexes COL1 and DSPP were higher than those in the control group.The difference was statistically significant(P＜0.05).Conclusion Dental pulp injury can induce the immune defense response.If the inflammation is not well controlled,it will stimulate the calcification of dental pulp cavities.iRoot BP Plus can better regulate the dental pulp microenvironment,control the development of inflammation,reduce the formation of adverse calcified masses in the pulp cavity after pulp injury,and preserve more pulp tissue.

Maxillary first molar teeth usually have 4 cusps,a few teeth have stuck cusps on the lingual side of the mesial tongue tip,while the presence of additional cusp on the buccal side of the mesial buccal tip is rarely reported,and it is even more rare for the cusp to connect with the dentin,cementum and pulp cavity of the main crown and fuse together to form C-shaped roots.A case of the buccal supernumerary cusp of the right maxillary first molar with C-shaped root canal was reported.

Objective:To assess the cytotoxicity of self-adhesive resin cement RelyXTM U200 on human periodontal ligament fibro-blasts(HPDLFs)under different light treatment modes.Methods:The self-adhesive resin cement RelyXTM U200 was cured by immediate light(A),intermittent light(B),delayed light(C)and no light(D)treatment respectively.The HPDLFs were cultured with the specimen extracts under different light modes.The proliferation ability and apoptosis level of the cells in the groups were detected by CCK-8 test and flow cytometry apoptosis test.SPSS 20.0 software was used to analyze the cytotoxicity of specimens to HPDLFs.Results:At 24 h after light treatment the cytoxicity(grade)of group A,B,C and D was 1,2,3 and 4,at 72 h 1,2,2 and 3,respectively.At 72 h,the apoptosis index(％)of the cells in A,B,C and D groups was 6.38％±0.94％,16.34％±1.67％,24.13％±1.43％and 38.34％±2.75％respecitvely.Conclusion:The cytotoxicity of self-adhesive resin cement is the greatest under no light treatment mode and the least under immediate light treatment mode.

Objective To investigate the effect of iRoot BP Plus on the repair of dental pulp cavity during pulp injury in rats,and to explore the possible role of iRoot BP Plus in the process of damage repair.Methods Bilateral maxillary first molars of 60 8-week-old SD rats were treated with direct pulp capping after pulp opening.They were divided into iRoot BP Plus group(BP group)and control group.After histological processing,the damage of dental pulp tissue and the calcification of pulp cavities were observed by microCT and HE staining.mRNA was extracted from rat dental pulp tissue,and the expression of inflammation and mineralization genes were detected by real-time quantitatitive PCR.Results The results of this study showed that the dental pulp tissue had different degrees of calcification at 1,4 and 7 days after direct pulp capping.There was no significant difference between the BP group and the control group on the 1st day after the operation,but on the 4th and 7th day after the operation,a regular calcified bridge was formed at the pulp hole in the BP group,and more pulp tissue was retained in the pulp cavity.In the control group,a large area of irregular calcified tissue was formed below the pulp hole.HE staining results showed that the pulp tissue had a heavy inflammatory response,and a large number of inflammatory cells infiltrated near the pulp orifice on the first day after the operation.On the 4th and 7th days after the opera-tion,mineralized tissue began to form near the pulp orifice in the BP group,and healthier pulp tissue was retained in the pulp cavity.The gene levels of IL-1β and TNF-α in the BP group were lower than those in the control group,and the gene expression levels of min-eralization indexes COL1 and DSPP were higher than those in the control group.The difference was statistically significant(P＜0.05).Conclusion Dental pulp injury can induce the immune defense response.If the inflammation is not well controlled,it will stimulate the calcification of dental pulp cavities.iRoot BP Plus can better regulate the dental pulp microenvironment,control the development of inflammation,reduce the formation of adverse calcified masses in the pulp cavity after pulp injury,and preserve more pulp tissue.

Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.