Corcoranmorrow8978

Root canal obturation is conducted by using filling materials to tightly seal the root canal system after the procedure of preparation in order to control infection and promote periapical healing. The quality of root canal obturation is one of the essential factors affecting the prognosis of root canal treatment. Qualified root canal filling is defined as a homogeneous radiographic apical filling within the cemento-dentine junction with neither overfilling nor underfilling. This review elucidates the long-term outcome of root canal overfilling and its causes, the influence of apical overfilling on adjacent structures and the prevention and management of overfilling, so as to help the clinicians achieving a better outcome of root canal treatment and obtaining an optimal long-term prognosis.As the national key discipline and the initiator of oral and maxillofacial deformity group, the Department of Oral and Maxillofacial Surgery persisted in teaching, designed a novel teaching form combining theoretical knowledge and online software practice according to the characteristics of our discipline and carried out "cloud training" via the National Oral Telemedicine Education Platform. Ten lecturers, 325 theoretical students and 50 practical students were investigated by questionnaire in the present study with questions focusing on the geographical distribution and composition of personnel, etc. The results showed that the online course covered a wide range of students and achieved high acceptance and satisfaction rate. The first online software operation course was conducted in an orderly manner, with timely interaction between teachers and students. The students were able to master the design process skillfully. This "cloud training" has achieved good results, but there are still a series of problems that have yet to be resolved, such as network stalls and protection of intellectual property rights. Under the new form, the exploration and analysis of the new mode of online telemedicine specialist education will provide some practical reference for the National Clinical Research Center for Oral Diseases to carry out online telemedicine teaching in the future.Objective To measure and analyze the spherical radius of Monson of normal young people in Guangdong province using cone-beam CT (CBCT), and to establish a personalized measurement method of the spherical radius of Monson to provide a reference for clinical application of Monson spherical radius in occlusal reconstruction. Methods Sixty healthy young adults from physical examination population at Stomatology Hospital of Guangzhou Medical University [30 males and 30 females, aged (22.1±2.0) years 18-26 years) were recruited, and their CBCT were taken. Three-dimensional reconstruction of CBCT data was carried out, and the reconstructed models were fixed, traced and measured. The difference of Monson spherical radius between male and female was compared by using a single sample t-test. Results The Monson spherical radius was (100.72±4.89) mm. The Monson spherical radius of male and female were (103.48±4.19) mm and (97.97±3.93) mm respectively. The difference between male and female was statistically significant (P less then 0.01). Conclusions CBCT can be used to accurately measure the spherical radius of Monson and can be used as a reference for reconstruction of occlusal plane.Objective To evaluate the biomechanical behaviors of different framework materials in implant-supported fixed mandibular prosthesis using three-dimensional finite element analysis. Methods A model of implant-supported fixed mandibular prosthesis was established. The simulations were divided into six groups according to the framework materials pure titanium, cobalt-chromium alloy, gold alloy, zirconia, polyether ether ketone (PEEK) and carbon fiber-reinforced PEEK. An oblique load of 300 N with a 75° angle to the occlusal plane was applied from the lingual side on the buccal cusps of the two premolars and the first molar teeth. The stresses on implants, surrounding bones and frameworks were analyzed and compared among the framework materials both quantitatively and qualitatively. Results In implant-supported fixed mandibular prosthesis model, the highest stresses were located around the neck of the implants and cortical bone during oblique loading among six designs. In addition, the stresses were concentrated on the buccal and distal cortical bone around the implants of the posterior region. Stress values of implants and cortical bones from low to high were as follows zirconia, cobalt-chromium alloy, pure titanium, gold alloy, carbon fiber-reinforced PEEK, PEEK. The von Mises stress values of implant and cortical bone in the first molar site of PEEK framework material were 44.96 and 29.13 MPa, while the von Mises stress values of implant and cortical bone in the first molar site of zirconia framework material were 21.29 and 17.79 MPa. The zirconia and medal framework materials were more advantageous in stress distribution around implants than PEEK framework material. Conclusions In implant-supported fixed mandibular prostheses, biomechanical analysis showed that the zirconia and medal framework materials were more advantageous in stress distribution around implants than PEEK framework materials.Objective To study the influence of non-thermal atmospheric pressure plasma (NTAPP) on dentine surface temperature, wettability and morphology of collagen fibrils under different treatment condition. Methods Helium was used as the operating gas at the flow rate of 3, 4, 5 L/min respectively. The plasma jet was operated at various input power of 8, 9, 10, 11 W. Thermal accumulation on human dentine surface (6 specimens per group, acquired from Department of Stomatology, The First Affiliated Hospital of Xi'an Medical University and Department of Stomatology, The Second Affiliated Hospital of Xi'an Medical University) of each group was measured continuously at 5 s intervals for 60 s by infrared thermography. Subasumstat Mean values were calculated and temperature curves were drawn. Dentine surface contact angles were measured after NTAPP treatment for 5, 10, 15, 20 s with gas flow rate and input power described above. The micro structure of the collagen fibrils of the negative control group (without NTAPP treatment) and NTAPP treatment groups (5 L/min gas flow rate, input power of 8, 9, 10, 11 W and treating time for 5, 10, 15, 20 s) was observed by field emission scanning electron microscopy (FE-SEM).