ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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 in 36 male 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.
ABSTRACT
Objective To explore the clinical therapy for cyclosporine A(CsA)-induced gingival overgrowth (GO) and the pathological changes in gingival overgrowth tissues.Methods Nine cases of CsA-induced GO after renal transplantation were subjected to periodontal non-surgical treatment and surgical treatment.Under light and electron microscopy,the pathological changes in CO tissues were observed.Results The bleeding index(BI) and the plaque index(PLI) of patients were declined after periodontal treatment.GO recurred in 2 patients 6 months later and happened to recur in all 9 patients 12 months later(GOD≤1).At 18th month after transplantation,an obvioUS GO(GOD≥2)occurred in one patient,and re-operation was done to cut hyperplastic gingiva.At 48th month during the observation period,GO existed continuously but no more than 2 in GOD.There were 3 other patients who had their GO(GOD≥2)at 24th month after peridental treatment and re-operation was carried out to remove the hyperplasic gingivaL Under a light microscope,epithelial pegs constituted of basal cells and prickle cells elongated and presented as cancellation structure;spinus layer thickened:hyperkeratosis or parakeratosis occurred in cuticular layer where inflammatory cells infiltrated:collagen increased in proper layer.Under the transmission electron microscopy,the volume of fibroblasts in hyperplastic gingival tissues was increased,rough endoplansmic reticula in the intracytoplasm were abundant and expanded slightly,and there were a few of the apoptotic fibroblasts in the early stage.Conclusion BI and PLl were declined in patients taking CyA for a long-term who were subjected to periodontal and surgical treatments.GO recurred in some patients.The proliferation and differentiation of fibroblasts was not observed in hyperplastic gingival tissues.
ABSTRACT
The aim of this study was to assess the peri-implant parameters and evaluate the clinical status with the survival of dental implants in body of maxilla after treatments of oral tumor. A follow-up examination included 27 patients who underwent the ablative tumor and (or) reconstructive surgery during a 5-year period. The follow-up protocol included clinical examination, radiological evaluation, and an interview using a standardized questionnaire. The reasons related to implant failure were studied by comparing the amount of failure with the value of marginal bone resorption, probing pocket depth, and plaque index using statistical t-test. The relationship between smoking and implant failure was analyzed statistically by chi-square test. The results showed among the 112 implants observed after implant loading, 29 have failed with the failure rate being 22.14 ％. There was no significant correlation between the peri-implant status and the implant failure (P＞0.05), however, the association of smoking and implant failure was statistically tested (P＜0.05). It was suggested that the association of peri-implant status and implant failure in the maxilla after tumor surgery can't be statistically tested, however smoking was still a mainly significant factor.
ABSTRACT
The aim of this study was to assess the peri-implant parameters and evaluate the clinical status with the survival of dental implants in body of maxilla after treatments of oral tumor. A follow-up examination included 27 patients who underwent the ablative tumor and (or) reconstructive surgery during a 5-year period. The follow-up protocol included clinical examination, radiological evaluation, and an interview using a standardized questionnaire. The reasons related to implant failure were studied by comparing the amount of failure with the value of marginal bone resorption, probing pocket depth, and plaque index using statistical t-test. The relationship between smoking and implant failure was analyzed statistically by chi-square test. The results showed among the 112 implants observed after implant loading, 29 have failed with the failure rate being 22.14 %. There was no significant correlation between the peri-implant status and the implant failure (P>0.05), however, the association of smoking and implant failure was statistically tested (P<0.05). It was suggested that the association of peri-implant status and implant failure in the maxilla after tumor surgery can't be statistically tested, however smoking was still a mainly significant factor.
ABSTRACT
The expression of epidermal growth factor receptor (EGFR) and leucine-rich repeats and immunoglobulinqike domain 1 (LRIG-1) in humantrigeminal neurinoma was investigated and their effect on the origination and development of trigeminal neurinoma, and the relationship between them was studied. By using immunohistochemistry with tissue chip, the expression of EGFR and LRIG-1 was detected in 23 cases of trigeminal neurinoma. It was found that in the 23 cases, the expression rate of EGFR was 21.74 %, while that of the LRIG-1 was 78.26 %. There was a negative correlation between them. It wassuggested that LRIG-1 might inhibit the malignant differentiation and proliferation of the trigeminal neurinoma possibly by the negative feedback loop of EGFR.
ABSTRACT
In order to study the character of periodontal ligament cells (PDLCs) attaching on commercially pure titanium (cpTi) by morphology and metrology on the early stage (24 h), 1 x 10(5)/ml PDLCs in 2 ml culture medium were seeded on cpTi discs fixed in 24-well culture plates. Morphology of cell attachment was observed by contrast phase microscope, scanning electron microscope (SEM) and fluroscence microscopy. Cell adhesion was analyzed by MTT at 0.5, 1, 2, 4 h respectively. PDLCs could attach and spread on cpTi discs. SEM showed that PDLCs had pseudopod-like protuberance. PDLCs showed different attaching phases and reached saturation in cell number at 2 h. It was concluded that PDLCs had good biocompatibility with cpTi, and showed a regular and dynamic pattern in the process of attaching to cpTi.
Subject(s)
Humans , Biocompatible Materials , Pharmacology , Cell Adhesion , Cell-Matrix Junctions , Cells, Cultured , Dental Implants , Periodontal Ligament , Cell Biology , Surface Properties , Time Factors , Titanium , PharmacologyABSTRACT
In order to investigate the maxillary preprosthetic situation after oral tumor treatment and/or reconstructive surgery, based on the review of case history and the clinical records 47 cases were analyzed after oral tumor treatment and/or reconstruction, including residual maxillary bone, intermaxillary relationships, defection of maxilla and oral situation after radiation therapy. The results showed that the residual maxillary bone was useful for implantation in the front alveolar bone and zygoma area. The maxillary preprosthetic situation after tumor treatment and/or reconstructive surgery was difficult due to maxillary resection, intermaxillary relationships, unsuitable soft and hard tissue transfer and the irradiation. It is suggested that the maxillary preprosthetic situation after oral tumor treatment is getting worse not only due to maxillary resection and/or irradiation, but surprisingly also due to mandibular resection and/or irradiation.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Alveolar Bone Loss , General Surgery , Alveolar Process , Maxilla , General Surgery , Maxillary Neoplasms , Drug Therapy , Radiotherapy , General Surgery , Mouth Neoplasms , Drug Therapy , Radiotherapy , General Surgery , Oral Surgical Procedures, Preprosthetic , Methods , Plastic Surgery Procedures , Retrospective StudiesABSTRACT
In order to study the character of periodontal ligament cells (PDLCs) attaching on commercially pure titanium (cpTi) by morphology and metrology on the early stage (24 h), 1 x 10(5)/ml PDLCs in 2 ml culture medium were seeded on cpTi discs fixed in 24-well culture plates. Morphology of cell attachment was observed by contrast phase microscope, scanning electron microscope (SEM) and fluroscence microscopy. Cell adhesion was analyzed by MTT at 0.5, 1, 2, 4 h respectively. PDLCs could attach and spread on cpTi discs. SEM showed that PDLCs had pseudopod-like protuberance. PDLCs showed different attaching phases and reached saturation in cell number at 2 h. It was concluded that PDLCs had good biocompatibility with cpTi, and showed a regular and dynamic pattern in the process of attaching to cpTi.
Subject(s)
Biocompatible Materials/pharmacology , Cell Adhesion , Cell-Matrix Junctions , Cells, Cultured , Dental Implants , Periodontal Ligament/cytology , Surface Properties , Time Factors , Titanium/pharmacologyABSTRACT
In order to investigate the influence of radiation therapy after the treatment of maxillary implant-supported prostheses, 27 patients received a total of 131 implants in maxilla after oral cancer treatment and/or reconstructive surgery. Among them, 25 received maxillary implant-supported prostheses. The cumulative survival rates of implants and prostheses were evaluated by the product-limit-estimates method according to Kaplan-Meier. The cumulative survival rate of implants and prostheses in irradiated patients was compared with that in non-irradiated patients by statistical Log-rank test. The results showed that 112 implants were observed after implant loading. The implants cumulative survival rate was approximately 65% for overall patients. The cumulative prosthesis successful rate was approximately 88% for all 25 patients. Log-rank test analysis revealed that there was a significant difference in cumulative implants survival rates between non-irradiated and irradiated maxillary bone (P < 0.01). It was concluded that the implants and prostheses in irradiated patients have significantly lower survival rates than in non-irradiated patients.
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Carcinoma, Squamous Cell , Radiotherapy , General Surgery , Dental Prosthesis, Implant-Supported , Graft Survival , Radiation Effects , Mandibular Prosthesis , Maxilla , General Surgery , Maxillofacial Prosthesis , Maxillofacial Prosthesis Implantation , Mouth Neoplasms , Radiotherapy , General Surgery , Osseointegration , Pilot Projects , Radiation Injuries , Retrospective Studies , Survival Rate , TitaniumABSTRACT
Objective To analyze the reasons of the occlusal disorder after mistaken concrescence of maxillofacial fracture, to observe the effect of the physiotherapy for the masticatory movement and the masticatory efficiency after occlusal reconstruction with fixed prosthesis. Methods The reasons of occlusal disorder of 45 patients were analyzed by reviewing the case history and clinical examination. Ultrasound diathermy and laser irradiation were used to help improve masticatory movement. The fixed prosthesis was used to reconstruct the occlusal relationship. Masticatory efficiency was measured with the method of sift out before treatment, one month and one year after treatment. Results The main reason of occlusal disorder was the delay of treatment because of the other treatment of body after trauma. The physiotherapy was effective in improving the masticatory movement. Statistically analysis showed the significantly difference before and after occlusal reconstruction with fixed prosthesis ( P