Objective: To evaluate the antiseptic effect of combined using of 5% sodium hypochlorite and calcium silicate-based root canal sealer against Enterococcus faecalis (Ef) biofilms in infected dentinal tubules in vitro. Methods: Cells of Ef were inoculated into the dentinal tubules of single-rooted teeth (without caries, periapical lesions and malformations extracted due to periodontal disease or orthodontic reasons; collected from Department of Maxillofacial Surgery, The First Affiliated Hospital of Zhengzhou University) with centrifugation and incubated in brain-heart infusion (BHI) to form 3-week-old biofilms. The infected samples were subjected to sodium hypochlorite or sterile water bathing for 10 minutes followed by calcium silicate-based root canal sealer (iRoot SP) (calcium silicate-based group), Gutta-percha group and sterile water group placed on the root canal wall for 1, 4 and 12 weeks. There were two samples in each treatment at each point. The antiseptic effectiveness of combined use of sodium hypochlorite and calcium silicate-based root canal sealer was analyzed by laser scanning confocal microscope (LSCM), ANOVA and LSD-t test. Results: After treatment with 5% sodium hypochlorite, in calcium silicate-based group for 4 and 12 weeks more Ef biofilm cells [(75.3±3.5)% and (74.8±3.8)%] were killed than in Gutta-percha group [(65.9±4.1)% and (63.0±3.7)%] and sterile water group [(63.9±4.0)% and (64.2±3.5)%] (P<0.05). After being treated with sterile water, the proportion of dead bacterial cells in calcium silicate-based group for 1, 4 and 12 weeks [(27.5±4.6)%, (43.0±4.4)% and (40.3±6.1)%] were more than those in Gutta-percha group and sterile water group (P<0.05). After being treated with 5% sodium hypochlorite or sterile water, more biofilm bacteria were killed in calcium silicate-based group for 4 and 12 weeks than in calcium silicate-based group for 1 week (P<0.05). Conclusions The combined use of sodium hypochlorite and calcium silicate-based root canal sealer kills more biofilm cells in infected dentinal tubules.

To evaluate the antiseptic effect of combined using of 5% sodium hypochlorite and calcium silicate?based root canal sealer against Enterococcus faecalis (Ef) biofilms in infected dentinal tubules in vitro . Methods Cells of Ef were inoculated into the dentinal tubules of single?rooted teeth (without caries, periapical lesions and malformations extracted due to periodontal disease or orthodontic reasons; collected from Department of Maxillofacial Surgery, The First Affiliated Hospital of Zhengzhou University) with centrifugation and incubated in brain?heart infusion (BHI) to form 3?week?old biofilms. The infected samples were subjected to sodium hypochlorite or sterile water bathing for 10 minutes followed by calcium silicate?based root canal sealer (iRoot SP) (calcium silicate?based group), Gutta?percha group and sterile water group placed on the root canal wall for 1, 4 and 12 weeks. There were two samples in each treatment at each point. The antiseptic effectiveness of combined use of sodium hypochlorite and calcium silicate?based root canal sealer was analyzed by laser scanning confocal microscope (LSCM), ANOVA and LSD?t test. Results After treatment with 5% sodium hypochlorite,in calcium silicate?based group for 4 and 12 weeks more Ef biofilm cells [(75.3 ± 3.5)% and (74.8 ± 3.8)% ] were killed than in Gutta?percha group [(65.9±4.1)% and (63.0±3.7)%] and sterile water group [(63.9±4.0)% and (64.2±3.5)%] (P<0.05). After being treated with sterile water, the proportion of dead bacterial cells in calcium silicate?based group for 1, 4 and 12 weeks [(27.5±4.6)%, (43.0±4.4)% and (40.3±6.1)%] were more than those in Gutta?percha group and sterile water group (P<0.05). After being treated with 5% sodium hypochlorite or sterile water, more biofilm bacteria were killed in calcium silicate?based group for 4 and 12 weeks than in calcium silicate?based group for 1 week (P<0.05). Conclusions The combined use of sodium hypochlorite and calcium silicate?based root canal sealer kills more biofilm cells in infected dentinal tubules.

Objective: To evaluate the antimicrobial activity of nonequilibrium plasma against Enterococcus faecalis (Ef) biofilms in vitro and to obtain novel evidence of root canal disinfection with nonequilibrium plasma. Methods: Sterile cover slips and single-rooted canals were filled with Ef and incubated to form 1-week-old and 3-week-old biofilms, respectively. The infected samples were subjected to nonequilibrium plasma, 2% chlorhexidine digluconate (CHX) and saline for 3, 10 and 30 minutes, respectively. After treatment, the killing effectiveness of nonequilibrium plasma was analyzed by using laser scanning confocal microscopy (LSCM) and colony forming unit (CFU) counting. Results: The 3-dimentional reconstruction LSCM images showed that about 48.3%-79.8% of 1-week-old Ef biofilm cells and 40.0%-67.4% of 3-week-old biofilm cells were killed by nonequilibrium plasma and 2% CHX compared to saline (P<0.05). The proportion of killing activity was lower after 3 minutes (40.0%-50.9% killing) than after 10 minutes (65.3%-77.8% killing) and 30 minutes (66.4%-79.8% killing) (P<0.05). And the killing of biofilm bacteria was fastest during the first 3 minutes (13.3%-17.0% killing per minute) and slow down greatly after 10 minutes. Remarkably more bacteria were killed in 1-week-old Ef biofilms (48.3%-79.8% killing) than in 3-week-old biofilms (P<0.05). Conclusions The nonequilibrium plasma killed more Ef biofilm cells in infected root canals showed promotional as an additional approach against bacterial biofilms during root canal disinfection.

Objective To evaluate the effect of ultrasound guided via chest puncture injection and ultrasound targeted microbubble destruction(UTMD) mediated the angiogenin 1 (Ang1) gene therapy in myocardial infarction (MI) canines.Methods Thirty nine dogs were divided into three groups (each group 13 dogs):① MI group (MI dogs without treatment);② intravenous injection group (MI dogs with intravenous injection and UTMD treatment);③ myocardial injection group (MI dogs with myocardial injection and UTMD treatment).Four weeks later,the safety and incidence of complications were compared.The dimensions and systolic function of left ventricular were measured by echocardiography.The percentage of collagen fiber was assessed by Masson.CD31 was applied for quantifying capillary density.The Ang1 protein was detected by Western blotting.Results ①The survival and complications showed no significant difference among the 3 groups(allP ＞0.05).②Compared with MI group,the left ventricular end systolic dimension (LVESD)reduced and the left ventricular ejection fraction (LVEF) increased in intravenous injection group;the left ventricular end-diastolic dimension (LVEDD) and LVESD were both reduced in myocardial injection group,the LVEF was increased significantly(all P ＜0.05).③ The immunohistochemistry showed lower collagen fiber percentage and higher blood vessel density in myocardial injection group than those in the other groups(P ＜0.05).④The relative quantity of Ang1 was significantly higher in myocardial injection group than those of the other groups.The differences were statistically significant (P ＜0.05).Conclusions The combination of ultrasound guided via chest puncture injection and UTMD is a safe and effective method for gene transfection.It mediates Ang1 gene transfection that can promote angiogenesis after MI and improve left ventricular systolic function.

Objective To evaluate the left ventricular synchrony after myocardial infarction (MI) by ultrasound targeted microbubbles destruction (UTMD)-mediated angiogenin 1 (Ang1) gene transfection in canine.Methods Twenty-one dogs were divided into three groups (n =7 in each group):①control group (healthy dogs);②MI group (MI dogs without treatment);③UTMD group (MI dogs with UTMD treatment).One month later,the size and systolic function of heart were measured by echocardiography.The synchronization parameters derived from two dimensional-speckle tracking imaging(2D-STI) included the standard deviation and maximum difference of time to peak strain for all left ventricular segments (Tls-SD,Trs-SD,Tcs-SD,Tls-Dif,Trs-Dif and Tcs-Dif).CD31 and α-SMA were applied for quantifying capillary and arteriolar density.The Ang1,SERCA2a and PLB protein were detected by Western blotting.Results ① One month later,the conventional ultrasonic parameters were compared among three groups,the LVEDD,LVESD and E/e'increased and LVEF,e'and E/A reduced in MI group than those in control group,all of them partially recovered in UTMD group than those in MI group,but were still lower than those in control group (P ＜0.05);②The left ventricular synchrony parameters of Tls-SD,Tls-Dif and Trs-SD showed significant differences among the three groups(P ＜0.05),the degree of dyssynchrony increased in MI group than control group,they were lower in UTMD group than those in MI group.The Tcs-SD,Tcs-Dif and Trs-Dif showed no significant difference among three groups (P ＞ 0.05);③ The immunohistochemistry showed the higher blood vessel density in UTMD group than that in MI group(P ＜ 0.05);④The relative quantity of Ang1 was significantly higher in UTMD group.The relative quantity of SERCA2a protein was lower in MI group than that in control group,increased in UTMD group,the trend of PLB was contrary to it.The differences were statistically significant (all P ＜0.05).Conclusions The UTMD-mediated Ang1 gene transfection can promote angiogenesis after MI,reverse left ventricular remodeling and improve left ventricular synchrony.The myocardial synchrony may be related to the expression of calcium ions key protein SERCA2a and PLB.

Previously,the choice of prosthetic implant-retained overdentures has depended on data from previous studies about the retention-fatigue strength of the attachment system selected.Little or no data have been available on the correlation between the attachment system selected and the overdenture support configuration.The purpose of the present study was to evaluate the retention force and fatigue resistance of three attachment systems and four support designs of overdenture prosthesis.Four lower edentulous acrylic models were prepared and eight combinations of attachments groups were investigated in the study.These included:O-Rings with mini-dental implants (MDIs),Dalbo elliptic with Dalbo Rotex and fabricated flexible acrylic attachments with both MDI and Dalbo Rotex.The study was divided into four test groups:groups A and B,controls,and groups C and D,experimental groups.Control group A contained three overdenture supports:two free standing MDIs in the canine region and at the midline,and one simulated tooth root with Dalbo Rotex screwed in.Control group B contained four overdenture support foundations:two free standing MDIs in the right canine region and the first premolar region,and two simulated tooth roots with Dalbo Rotex screwed in at the same MDI position,but on the left side of the model.Experimental group C contained three overdenture support foundations:two free standing MDIs in the canine region and at the midline,and one simulated tooth root with MDI screwed in.Experimental group D contained four overdenture support foundations:two free standing MDIs in the right canine region and the first premolar region,and two simulated tooth roots with MDIs screwed in at the same MDI position,but on the left side of the model.Each group was further divided into two subgroups according to attachment type used.Five samples were prepared for each group.Retention force (N) values were recorded initially (0 cycles) and after 360,720,1440 and 2880 insertion and removal cycles.During the tensile test a cross-head speed of 10 mm/min was applied.Values of absolute force (AF) and relative force (RF) were statistically analyzed by two-way ANOVA and multiple comparison Tukey's tests between groups and cycles periods.The results of fatigue tests showed a 50％ reduction in retention force in the subgroups with flexible attachments.A triangular design of overdenture support foundations with O-Ring attachments revealed the lowest value of AF and a relatively high reduction in RF.The four overdenture support designs with flexible acrylic attachments improved the retention force and reduced the fatigue retention.Furthermore,the results of the investigation demonstrate that flexible acrylic attachments for both teeth and implant-supported overdentures offer a wide range of retention forces.

Previously, the choice of prosthetic implant-retained overdentures has depended on data from previous studies about the retention-fatigue strength of the attachment system selected. Little or no data have been available on the correlation between the attachment system selected and the overdenture support configuration. The purpose of the present study was to evaluate the retention force and fatigue resistance of three attachment systems and four support designs of overdenture prosthesis. Four lower edentulous acrylic models were prepared and eight combinations of attachments groups were investigated in the study. These included: O-Rings with mini-dental implants (MDIs), Dalbo elliptic with Dalbo Rotex and fabricated flexible acrylic attachments with both MDI and Dalbo Rotex. The study was divided into four test groups: groups A and B, controls, and groups C and D, experimental groups. Control group A contained three overdenture supports: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with Dalbo Rotex screwed in. Control group B contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with Dalbo Rotex screwed in at the same MDI position, but on the left side of the model. Experimental group C contained three overdenture support foundations: two free standing MDIs in the canine region and at the midline, and one simulated tooth root with MDI screwed in. Experimental group D contained four overdenture support foundations: two free standing MDIs in the right canine region and the first premolar region, and two simulated tooth roots with MDIs screwed in at the same MDI position, but on the left side of the model. Each group was further divided into two subgroups according to attachment type used. Five samples were prepared for each group. Retention force (N) values were recorded initially (0 cycles) and after 360, 720, 1440 and 2880 insertion and removal cycles. During the tensile test a cross-head speed of 10 mm/min was applied. Values of absolute force (AF) and relative force (RF) were statistically analyzed by two-way ANOVA and multiple comparison Tukey's tests between groups and cycles periods. The results of fatigue tests showed a 50% reduction in retention force in the subgroups with flexible attachments. A triangular design of overdenture support foundations with O-Ring attachments revealed the lowest value of AF and a relatively high reduction in RF. The four overdenture support designs with flexible acrylic attachments improved the retention force and reduced the fatigue retention. Furthermore, the results of the investigation demonstrate that flexible acrylic attachments for both teeth and implant-supported overdentures offer a wide range of retention forces.

Recently,plasma sterilization has attracted increasing attention in dental community for the atmospheric pressure non-equilibrium plasma jet (APNPs),which is driven by a kilohertz pulsed DC power,may be applied to the dental and oral diseases.However,it is still in doubt whether APNPs can effectively kill pathogenic bacteria in the oral cavity and produce no harmful effects on normal oral tissues,especially on normal mucosa.The aim of this study was to evaluate the bacterial-killing effect of APNPs in the biofilms containing a single breed of bacteria (Porphyromonas gingivalis,Pg.),and the pathological changes of the oral mucosa after treatment by APNPs.Pg.was incubated to form the biofilms in vitro,and the samples were divided into three groups randomly:group A (blank control);group B in which the biofilms were treated by APNPs (the setting of the equipment:10 kHz,1600 ns and 8 kV); group C in which the biofilms were exposed only to a gas jet without ignition of the plasma.Each group had three samples and each sample was processed for up to 5 min.The biofilms were then fluorescently stained,observed and photographed under a laser scanning confocal microscope.In the animal experiment,six male Japanese white rabbits were divided into two groups randomly (n=3 in each group) in terms of the different post-treatment time (1-day group and 5-day group).The buccal mucosa of the left side and the mucosa of the ventral surface of the tongue were treated by APNPs for 10 min in the same way as the bacterial biofilm experiment in each rabbit,and the corresponding mucosa of the other sides served as normal control.The clinical manifestations of the oral mucosa were observed and recorded every day.The rabbits were sacrificed one or five day(s) after APNPs treatment.The oral mucosa were harvested and prepared to haematoxylin and eosin-stained sections.Clinical observation and histopathological scores were used to assess mucosal changes.The results showed the obvious P.g.biofilms were formed at 10 days,and most of the bacteria in groups A and C were alive under a laser scanning confocal microscope,but the bacteria in the group B were almost all dead.In animal experiment,no ulcers,anabrosis and oral mucositis were found in both the 1-day and 5-day groups.The average mucous membrane irritation index was -0.83 and -0.67 in the 1-day and 5-day groups,respectively,suggesting that no intense mucosal membrane irritation responses occurred.It was concluded that APNPs could effectively kill P.g.in the biofilms and did not cause any pathological changes in the normal mucosa,suggesting that the plasma jet (APNPs) may be applied to oral diseases as a novel sterilization device in the future.

Recently, plasma sterilization has attracted increasing attention in dental community for the atmospheric pressure non-equilibrium plasma jet (APNPs), which is driven by a kilohertz pulsed DC power, may be applied to the dental and oral diseases. However, it is still in doubt whether APNPs can effectively kill pathogenic bacteria in the oral cavity and produce no harmful effects on normal oral tissues, especially on normal mucosa. The aim of this study was to evaluate the bacterial-killing effect of APNPs in the biofilms containing a single breed of bacteria (Porphyromonas gingivalis, P.g.), and the pathological changes of the oral mucosa after treatment by APNPs. P.g. was incubated to form the biofilms in vitro, and the samples were divided into three groups randomly: group A (blank control); group B in which the biofilms were treated by APNPs (the setting of the equipment: 10 kHz, 1600 ns and 8 kV); group C in which the biofilms were exposed only to a gas jet without ignition of the plasma. Each group had three samples and each sample was processed for up to 5 min. The biofilms were then fluorescently stained, observed and photographed under a laser scanning confocal microscope. In the animal experiment, six male Japanese white rabbits were divided into two groups randomly (n=3 in each group) in terms of the different post-treatment time (1-day group and 5-day group). The buccal mucosa of the left side and the mucosa of the ventral surface of the tongue were treated by APNPs for 10 min in the same way as the bacterial biofilm experiment in each rabbit, and the corresponding mucosa of the other sides served as normal control. The clinical manifestations of the oral mucosa were observed and recorded every day. The rabbits were sacrificed one or five day(s) after APNPs treatment. The oral mucosa were harvested and prepared to haematoxylin and eosin-stained sections. Clinical observation and histopathological scores were used to assess mucosal changes. The results showed the obvious P.g. biofilms were formed at 10 days, and most of the bacteria in groups A and C were alive under a laser scanning confocal microscope, but the bacteria in the group B were almost all dead. In animal experiment, no ulcers, anabrosis and oral mucositis were found in both the 1-day and 5-day groups. The average mucous membrane irritation index was -0.83 and -0.67 in the 1-day and 5-day groups, respectively, suggesting that no intense mucosal membrane irritation responses occurred. It was concluded that APNPs could effectively kill P.g. in the biofilms and did not cause any pathological changes in the normal mucosa, suggesting that the plasma jet (APNPs) may be applied to oral diseases as a novel sterilization device in the future.

The purpose of this study was to evaluate the effect of bone marrow mesenchymal stem cells(MSCs)transfected with the basic fibroblast growth factor(bFGF)-expressing recombinant adeno-associated virus vector(rAAV2-bFGF),on early angiogenesis of calvarial defects in rats.The MSCs were cultured and transfected with rAAV2-bFGF after differential adherence isolation.The transfection efficiency was detected by RT-PCR and Western blotting.The transfected MSCs were compounded with poly-DL-lactide/hydroxyapatite(PDLLA/HA)in vitro.The cranial defect models in36 malc SD rats were created.Nothing(group A),PDLLA/HA alone(group B),PDLLA/HA combined with MSCs(group C),and PDLLA/HA combined with rAAV2-bFGF transfected MSCs(group D)were implanted in rat calvarial defects.The specimens were harvested for hematoxylin-eosin staining on the day 1,3 and 7 after implantation.Factor Ⅷ immunohistochemical staining and histomorphometric analysis were carried out to evaluate neovascularization around the implantation.The results indicated that MSCs could indeed be successfully transfected with the rAAV2-bFGF vector.Histological and histomorphometric analysis revealed that the angiogenesis in group D was significantly enhanced as compared with the rest groups(P<0.05).These results strongly suggest that MSCs transfected with rAAV2-bFGF in combination with PDLLA/HA can effectively promote the early angiogenesis of calvarial defects in rats,which played an important role in creating an environment suitable for the survival and activity of transplanted cells for further applications in cranio-maxillofacial bone regeneration.