OBJECTIVES: This study aims to evaluate the short- to medium-term clinical efficacy of demineralized dentin matrix (DDM) particles applied during the immediate implantation of alveolar bone defects in the posterior region. METHODS: A total of 76 patients with 110 simple taper retentive implants were included in the conducted study and divided into Groups A and B in accordance with the bone grafting materials. Cone beam computed tomography and panoramic radiographs were taken immediately after implant surgery, immediate crown repair, and final follow-up time. The average follow-up time for Groups A and B was recorded. The primary observed clinical indicators were overall survival rate of the implant, bone resorption of the mesial and distal margins of the implant, buccal bone width resorption at the platform level and 1 mm below the platform, and bone height of the implant. Implant complication was a secondary observed clinical indicator. RESULTS: During the 1-to-5-year follow-up observation period, the mean follow-up of Group A was 38.2 months while that of Group B was 39.9 months. In Group A, two implants failed, one of which fractured, and implant overall survival rate was 96.4%. Four implants failed in Group B due to peri-implantitis, and implant overall survival rate was 92.6%. No statistically significant difference in implant overall survival rate was found between the two groups (P>0.05). In Group A, the average bone resorption in the mesial and distal margins of the implants was (1.011±2.047) mm and (0.841±2.183) mm, respectively. In Group B, the average bone resorption of the mesial and distal margins of the implants was (1.546±1.778) mm and (1.431±1.909) mm, respectively. No statistically significant difference was noted between the two groups (P>0.05). In Group A, buccal bone width resorption at the platform level and 1 mm below the platform of the implant was (0.782±2.084) mm and (0.681±2.307) mm, respectively. In Group B, buccal bone width resorption at the platform level and 1 mm below the platform of implant was (1.071±1.474) mm and (0.949±1.909) mm, respectively. No statistically significant difference was found between the two groups (P>0.05). In Group A, the buccal bone height of resorption of the implant was (1.044±2.214) mm. In Group B, the buccal bone height of resorption of the implant was (1.075±1.456) mm. No statistically significant difference in bone height was observed between the two groups (P>0.05). CONCLUSIONS During the 1-to-5-year follow-up observation period, DDM particles can effectively increase the height and width of alveolar bone, and they can achieve the same effect of maintaining alveolar bone contour and bone augmentation compared with deproteinized inorganic calf bone. DDM particles can be used as a potential new bone grafting material for the treatment of bone defects in clinical practice.
Humans ; Follow-Up Studies ; Dentin ; Cone-Beam Computed Tomography ; Dental Implants ; Male ; Female ; Adult ; Alveolar Bone Loss/surgery* ; Middle Aged ; Bone Transplantation ; Radiography, Panoramic ; Dental Implantation, Endosseous/methods* ; Immediate Dental Implant Loading

OBJECTIVES: To explore the related risk factors of early failure of simple taper retentive implants, and to provide theoretical guidance for clinical work. METHODS: Collect cases of patients who visited the Department of Stomatology of the Fourth Affiliated Hospital of Nanchang University from January 2021 to June 2024, received simple taper retentive implants, and had complete medical records. Taking the implants as the unit, analyze the influence of patient-related factors (gender, age, smoking history, hypertension history, diabetes history), implant-related factors (implant length, implant diameter, implant surface treatment), and surgical-related factors (implant site, implant timing, simultaneous maxillary sinus floor elevation, simultaneous bone augmentation) on the early failure of implants. Univariate analysis and multivariate analysis were adopted to explore the potential risk factors for early failure of simple taper retentive implants. RESULTS: A total of 3,533 simple taper retentive from 1,681 patients were included during the study period. Among them, 53 implants from 49 patients experienced early failure, with an early failure rate of 2.9% at the patient le-vel and 1.5% at the implant level. Multivariate analysis revealed that smoking (OR=2.148, P=0.021), the anterior mandibular region (OR=3.669, P=0.006), and the posterior maxillary region (OR=2.191, P=0.033) were risk factors for early failure of simple taper retentive implants. In the univariate analysis, simultaneous maxillary sinus floor elevation had a higher risk of early failure, but this effects was no longer significant in the multivariate analysis (P>0.05). CONCLUSIONS Smoking, the anterior mandibular region, and the posterior maxillary region are risk factors for the early failure of simple taper retentive implants, and could be comprehensively considered in the preoperative treatment plan.
Humans ; Risk Factors ; Male ; Female ; Middle Aged ; Dental Implants ; Adult ; Smoking/adverse effects* ; Dental Restoration Failure ; Aged

Objective To explore the effect and preliminary mechanism of the plant-derived immunostimulatory molecule,ophiopogonin,on enhancing the immune response of a subunit vaccine with the receptor-binding domain(RBD)of coronavirus spike protein as the antigen.Methods CCK-8 assay was used to determine the cytotoxicity of ophiopogonin D'(OPD')on bone marrow-derived dendritic cells(BMDCs).Female Balb/c mice were randomly divided into RBD,RBD/OPD',RBD/Alum,and control groups.The immunization dose was 5 μg of antigen per mouse and 100 μg of adjuvant per mouse,and immunization was carried out according to the intramuscular injection immunization procedure on days 0,21,and 42.The titers of specific IgG and its subtype antibodies were detected by ELISA.The cytokine levels in the supernatant of splenocytes were detected using ELISA.The number of splenocytes secreting IFN-γ was detected by ELISpot.Laser confocal microscopy was employed to observe the uptake of antigen by BMDCs.The phagocytic ability of BMDCs for antigen was quantitatively analyzed by flow cytometry.The mechanism of its enhanced immune effect was preliminarily explored using transcriptomics technology combined with bioinformatics research.Results When the concentration of OPD'was less than 5 μg/mL,the survival rate of BMDCs was 100%.After a single intramuscular injection in mice,except for a slight decrease in body weight,the other biochemical indicators were within corresponding normal ranges.After intramuscular injection immunization of the vaccine,the titers of serum-specific IgG,IgG1,and IgG2a in the RBD/OPD'group were significantly higher than those in the RBD group(P<0.05).Compared with the RBD group,the RBD/OPD'group induced a high-level Th1 cell immune response of IL-1β,TNF-α,and IFN-γ(P<0.01)and had more lymphocytes secreting IFN-γ(P<0.001).Laser confocal microscopy displayed that BMDCs took up more antigens after OPD'treatment,which was further confirmed with flow cytometry in quantitative analysis on antigen uptake rate(P<0.01).Transcriptomics results indicated that there was more significant enrichment of the PPAR signaling pathway in the RBD/OPD'group than the RBD group,suggesting that OPD'may activate the PPAR signaling pathway to exert its adjuvant effect.Conclusion OPD'effectively enhances the immune response of the RBD subunit vaccine,and its action mechanism may be related to the activation of the PPAR signaling pathway.

Objective To prepare tubeimoside Ⅲ nanoemulsion(TBMⅢ-NE)and evaluate its adjuvant effect in vaccines.Methods TBMⅢ-NE was prepared using low-energy emulsification.Dynamic light scattering was used to characterize the particle size and polydispersity index of the obtained TBMⅢ-NE,and transmission electron microscopy(TEM)was employed to observe the morphology.CCK-8 assay was utilized to determine the cytotoxicity of TBMⅢ-NE on bone marrow-derived dendritic cells(BMDCs).The in vitro safety of TBMⅢ-NE was evaluated using a hemolysis assay.The ability of TBMⅢ-NE to promote the phagocytosis of antigens by DC2.4 cells was observed using confocal laser microscopy.After co-incubation of TBMⅢ-NE with BMDCs,the expression levels of CD40,CD86,MHC-Ⅰ,and CCR7 on the surface of BMDCs were detected using flow cytometry,and the levels of cytokines in the supernatant of BMDCs were measured using enzyme-linked immunosorbent assay(ELISA).After female BALB/c mice were immunized with the SARS-CoV-2 antigen RBD in combination with TBMⅢ-NE,ELISA was conducted to determine the serum levels of specific IgG,IgG2a,and IgG1 antibodies.The number of specific IFN-γ-secreting cells in mouse splenocytes was detected using enzyme-linked immunospot(ELISpot)assay.Results The prepared blank nanoemulsion(BNE)and TBMⅢ-NE were in a particle size of 25.46 and 25.89 nm,and a polydispersity index of 0.214 and 0.125,respectively.TEM displayed that TBMⅢ-NE was in uniform sphere and well dispersed.When the TBMⅢ-NE adjuvant was diluted by 400-fold,the survival rate of BMDCs was approximately 86%.Compared with free TBMⅢ,the hemolytic toxicity of TBMⅢ-NE was significantly reduced(P<0.01).TBMⅢ-NE promoted the phagocytosis of antigens by DC2.4 cells and significantly increased the expression of CCR7 on the surface of BMDCs(P<0.05),indicating its potential to promote more dendritic cells to effectively migrate to lymph nodes.TBMⅢ-NE also promoted the expression of IL-6 and IL-1β in the supernatant of BMDCs(P<0.05).When combined with RBD,TBMⅢ-NE significantly increased the levels of specific IgG,IgG2a,and IgG1 antibodies in mouse serum(P<0.01)and promoted the secretion of specific IFN-γ in splenocytes(P<0.01),indicating that TBM Ⅲ-NE could enhance specific cellular immune responses.Conclusion A stable and highly effective TBMⅢ-NE that can induce humoral and cellular immune responses is successfully prepared.

In recent years,the microorganisms residues in endoscopes have frequently resulted in cross transmis-sion or even the outbreak of hospital-associated infections.It is of great importance to carry out standardized bio-logical surveillance of endoscopes,find out the high-risk links of cleaning and disinfection,and take targeted inter-vention measures to reduce the incidence of endoscopy-related infection.Based on the related guidelines in China and abroad as well as the latest clinical practice researches,the biological surveillance sampling and culture for en-doscopes were summarized in the article so as to enhance the surveillance quality,ensure the reprocessing effect and guarantee the endoscopy-related quality and safety.

BACKGROUND:Stem cell mesenchyme within reactive softtissues has the potential to promote tissue regeneration.Demineralized dentin matrix,which has good biocompatibility,can be used as a scaffold material for the site preservation surgery to promote the attachment,proliferation,and differentiation of osteoblasts.OBJECTIVE:To evaluate the changes in alveolar bone height and width after 6 months of site preservation with demineralized dentin matrix after 1 month of extraction of affected teeth with preservation of reactive softtissues.METHODS:A total of 38 patients with 62 extraction sites were included.One month after the extraction of the affected teeth with preservation of reactive soft tissues,demineralized dentin matrix was used to perform site-preservation surgery.Cone-beam CT was taken preoperatively,immediately postoperatively,and 6 months postoperatively to measure the proximal-medial bone height,central bone height,distal-medial bone height,buccal bone height,lingual bone height,and alveolar bone height,and alveolar bone width.Extraction defects were categorized as one-,two-,three-,or four-wall defects based on the number of alveolar fossa bone walls remaining after tooth extraction.Changes in bone volume were compared preoperatively,immediately postoperatively,and 6 months postoperatively.RESULTS AND CONCLUSION:No wound infection occurred at any site during bone healing.Compared with preoperative data,there was a significant increase in alveolar bone height and bone immediately postoperatively(P<0.05);there was also an increase in alveolar bone height but no change in alveolar bone width 6 months postoperatively(P>0.05).Compared with the immediate postoperative period,alveolar bone width was increased by(1.253±2.896)mm 6 months postoperatively,but there was no change in alveolar bone height(P>0.05).The bone height of the four bone defect types was significantly increased immediately and 6 months postoperatively(P<0.05),and no changes in the bone width were observed(P>0.05).Compared with the preoperative data,there was the least increase in proximal-medial bone volume in one-wall bone defects at 6 months postoperatively(P<0.05)and the most increase in proximal-medial bone volume in two-wall bone defects(P<0.05).These findings indicate that demineralized dentin matrix applied to site preservation can effectively prevent and slow down alveolar bone resorption after tooth extraction,and can rebuild the alveolar bone contour where resorption has occurred to a certain extent;preservation of reactive tissues applied to demineralized dentin matrix site preservation after tooth extraction can achieve wound closure with good clinical efficacy;demineralized dentin matrix applied to the alveolar socket site preservation with one-,two-,three-,and four-wall defects shares similar effects.However,demineralized dentin matrix is more effective for site preservation when applied to extraction sockets with intact bone walls.

In recent years,the microorganisms residues in endoscopes have frequently resulted in cross transmis-sion or even the outbreak of hospital-associated infections.It is of great importance to carry out standardized bio-logical surveillance of endoscopes,find out the high-risk links of cleaning and disinfection,and take targeted inter-vention measures to reduce the incidence of endoscopy-related infection.Based on the related guidelines in China and abroad as well as the latest clinical practice researches,the biological surveillance sampling and culture for en-doscopes were summarized in the article so as to enhance the surveillance quality,ensure the reprocessing effect and guarantee the endoscopy-related quality and safety.

BACKGROUND:Stem cell mesenchyme within reactive softtissues has the potential to promote tissue regeneration.Demineralized dentin matrix,which has good biocompatibility,can be used as a scaffold material for the site preservation surgery to promote the attachment,proliferation,and differentiation of osteoblasts.OBJECTIVE:To evaluate the changes in alveolar bone height and width after 6 months of site preservation with demineralized dentin matrix after 1 month of extraction of affected teeth with preservation of reactive softtissues.METHODS:A total of 38 patients with 62 extraction sites were included.One month after the extraction of the affected teeth with preservation of reactive soft tissues,demineralized dentin matrix was used to perform site-preservation surgery.Cone-beam CT was taken preoperatively,immediately postoperatively,and 6 months postoperatively to measure the proximal-medial bone height,central bone height,distal-medial bone height,buccal bone height,lingual bone height,and alveolar bone height,and alveolar bone width.Extraction defects were categorized as one-,two-,three-,or four-wall defects based on the number of alveolar fossa bone walls remaining after tooth extraction.Changes in bone volume were compared preoperatively,immediately postoperatively,and 6 months postoperatively.RESULTS AND CONCLUSION:No wound infection occurred at any site during bone healing.Compared with preoperative data,there was a significant increase in alveolar bone height and bone immediately postoperatively(P<0.05);there was also an increase in alveolar bone height but no change in alveolar bone width 6 months postoperatively(P>0.05).Compared with the immediate postoperative period,alveolar bone width was increased by(1.253±2.896)mm 6 months postoperatively,but there was no change in alveolar bone height(P>0.05).The bone height of the four bone defect types was significantly increased immediately and 6 months postoperatively(P<0.05),and no changes in the bone width were observed(P>0.05).Compared with the preoperative data,there was the least increase in proximal-medial bone volume in one-wall bone defects at 6 months postoperatively(P<0.05)and the most increase in proximal-medial bone volume in two-wall bone defects(P<0.05).These findings indicate that demineralized dentin matrix applied to site preservation can effectively prevent and slow down alveolar bone resorption after tooth extraction,and can rebuild the alveolar bone contour where resorption has occurred to a certain extent;preservation of reactive tissues applied to demineralized dentin matrix site preservation after tooth extraction can achieve wound closure with good clinical efficacy;demineralized dentin matrix applied to the alveolar socket site preservation with one-,two-,three-,and four-wall defects shares similar effects.However,demineralized dentin matrix is more effective for site preservation when applied to extraction sockets with intact bone walls.

Objective This test aimed to investigate the factors affecting the locking force between the implant and abutment and the amount of abutment subsidence in pure Morse taper connection implant systems.Methods With ref-erence to the Bicon implant abutment connection design,different types of implant specimens and their corresponding types of abutments were fabricated.The implant-abutment locking taper was uniformly 1.5°.The locking depths were 1.0,2.0,and 3.0 mm.The diameters of the locking column were 2.5,3.0,and 3.5 mm.The thicknesses of the outer wall of the implant were 0.15 and 0.30 mm.The loading forces of the testing machine were 200,300,and 400 N.At least 10 specimens of each group of implant-abutment were used.All specimens were loaded in the same manner using a univer-sal testing machine(finger pressure + specified loading force,five times).The total height of the implant-abut-ment was measured before finger pressure,after finger pressure,and after the testing machine was loaded for five times to calculate the amount of sinking of the abutment.Finally,the implant and abutment were pulled apart using the universal testing machine,and the subluxation force was observed and recorded.Results The test loading force,locking depth,and locking post diameter had an effect on the implant-abutment locking force and abutment subsidence.The implant-abutment locking force increased with the increase in the test loading force,locking depth,and locking post diameter(R=0.963,0.607,and 0.372,respectively),with the test loading force having the most significant effect.Abut-ment subsidence increased with the increase in test loading force(R=0.645)and decreased with the increase in locking depth and locking post diameter(R=-0.807 and-0.280,respectively),with locking depth having the most significant ef-fect on abutment subsidence.No significant correlation was found between the thickness of the outer wall of the implant and the change in the magnitude of the implant-abutment locking force.However,an increase in the thickness of the out-er wall of the implant decreased the amount of abutment subsidence,which was inversely correlated.Conclusion The locking force of the implant-abutment can be increased by adjusting the design of the pure Morse taper connection im-plant-abutment connection,increasing the locking depth and locking post diameter,and increasing the amount and num-ber of times the abutment is loaded during seating.Problems,such as loosening or detachment of the abutment,can be re-duced.The recommended abutment to be loaded should be no less than five times during seating to prevent the abutment from sinking and causing changes in the occlusal relationship in the later stages.Preliminary occlusal adjustments should only be conducted in the early stages of the use of temporary restorations,and final restorations and occlusal adjustments are recommended to be performed after using the abutment for a period of time.

Objective This study aims to evaluate the mid-and long-term clinical efficacies of simple taper retentive implants for immediate placement in chronic apical infected teeth in the posterior region.Methods A total of 36 pa-tients with 41 simple taper retentive implants were included in the study conducted.These patients underwent immediate implant treatment for teeth with chronic apical infection in the posterior region.The soft and hard tissues surrounding the implants were assessed and documented over a period of 5 years following the completion of crown restoration.Re-sults During the 5 years follow-up period,one implant failed with mobility,and the implant survival rate was 97.6％.The mean marginal bone resorption was(-0.74±1.03)mm from the immediate post-implant placement to the immediate post-crown restoration,and the difference in marginal bone heights between the two time points was statistically signifi-cant(P＜0.05).The mean marginal bone resorption was(-0.21±0.70)mm from the immediate post-crown restoration to the 5-year post-crown restoration,and the difference in marginal bone height between the two time points was not statisti-cally significant(P＞0.05).No significant difference(P＞0.05)was observed in bone resorption between mesial and distal,maxillary and mandibular,different tooth posi-tions,and different implant lengths.The soft tissue sur-rounding the implants remained healthy at the 5 years follow-up period,one implant exhibited peri-implantitis,and no mechanical complications were observed.The overall satisfaction of patients was good.Conclusion Immediate place-ment of simple taper retentive implants after thorough debridement of chronic infected alveolar socket in the posterior re-gion can achieve good mid-and long-term clinical outcomes after 5 years of loading.The soft and hard tissues were maintained in a steady state,which expanded the indications for immediate implantation.