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 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.

Objective To test experimentally Fluoro-Jade B(FJB) stain method for detecting degeneration of neurons in the basal ganglia. Methods Kainic acid(KA)-lesion model by stereotaxical injection of KA into striatum of rats,MPTP-lesion model by injection of MPTP into intraperitoneal cavity of mice,as well as KA-lesion model of cultured striatal cells were firstly prepared.FJB stain dye was then used to visualize degeneration of neurons in above KA-or MPTP-lesion models. Results KA-or MPTP-induced degenerative neurons including cell bodies and processes could be clearly visualized by FJB stain dye.In the brain sections,FJB-positive stained degenerative neurons were numerously observed in the striatum of KA-lesion rats and the substantia nigra pars compacta of MPTP-treated mice,but not detected in the control animals.Moreover,degenerative neurons were also detected with FJB stain in cultured striatal neurons.Semi-quantitative analysis on percentage(?s) of FJB-positive neurons constituting total cultured striatal neurons in unit area showed that degenerative neurons of KA-lesion group (8.42?1.09)% was evidently more than that of controls (3.42?0.45)%,P