BACKGROUND:Both Ms Coat and Green OrTM desensitizers can seal dentinal tubules effectively, isolate the dentinal tubule from external stimuli and also reduce the dentinal hypersensitivity. The scholars around the world have discussed their effects from the descriptive and qualitative view.
OBJECTIVE:To quantitatively assess and compare the sealing effects of Ms Coat and Green OrTM desensitizers on dentine tubules.
METHODS:Thirty fresh human third molar samples were made into 3-mm dentin specimens that were treated with 17% EDTA for 2 minutes and randomly divided into three groups: Ms Coat group, Green OrTM group and control group with no treatment. In the former two groups, MS Coat desensitizer and Green OrTM desensitizer were applied respectively on the dentin surfaces. Scanning electron microscope was used to observe the dentin surface and longitudinal sections.
RESULTS AND CONCLUSION: (1) Surface observation: In the control group, al of the dentinal tubules were exposed; in the MS Coat group, it was observed that almost al the dentinal tubules were obliterated; in the Green OrTM group, the dentin tubules were covered with irregular crystaline substance and only a smal number of exposed dentine tubules were visible but narrowed obviously. (2) Longitudinal profile observation: In the control group, the dentin tubules were strip-shaped and arranged in paralel without any blockage; in the MS coat group, the tubules were covered with dense sediments, and the dentinal tubules were basicaly closed; in the Green OrTM group, there were scaly crystaline material deposited within the dentinal tubules. Dentinal diameter and number of dentinal tubules were ranked as folows: control group > Green OrTM group > MS Coat group (P < 0.05). Both Ms Coat and Green OrTM desensitizers can occlude the tubules effectively, and moreover, the MS Coat is superior to the Green OrTM.

Objective:To study the maximum volume of oral cavity (MVOC) of the young adults with normal occlusion and to explore the correlation of MOVC with the height,weight,mouth opening degree and masticatory efficiency.Methods:100 volunteers with normal occlusion(50 for each sex) were enrolled.MVOC was measured by the maximum water capacity method,the height,weight,degree of mouth opening and masticatory efficiency value of the subjects were measured.Results:The average values of MVOC of the male and female were (117.63±15.31) ml and (92.08±14.06) ml respectively(P<0.01).MVOC was positively correlation with the height(r=0.67,P<0.01),weight(r=0.63,P<0.01),degree of mouth opening(r=0.47,P<0.01) and masticatory efficiency(r=0.45,P<0.01).Conclusion:MVOC is moderate-positively correlated and low-positively correlated with mouth opening degree and masticatory efficiency.

Objective:To explore the clinical characteristics and prognosis of metastatic sites symptom as the first manifestation in esophageal carcinoma patients with stage T 1 and T 2, and to provide a reference for clinical practice. Methods:The clinical data of 50 esophageal carcinoma patients with stage T 1 and T 2 who had lymph node or distant metastasis as the first symptom in Anyang Tumor Hospital of Henan Province from November 2007 to December 2019 were retrospectively analyzed. Survival analysis was performed by using Kaplan-Meier method. Univariate analysis was performed by using log-rank test. Results:Among 50 patients with esophageal carcinoma, lymph node metastases as the first symptom were found in 42 cases and distant organ metastases as the first symptom were found in 8 cases. The 1-, 3-, 5-year overall survival rates of patients with stage Ⅰ-Ⅱ and stage Ⅲ-Ⅳ were 58.7%, 49.0%, 16.3% and 56.1%, 12.2%, 0, respectively, and there was no statistically significant difference in OS of both groups ( P = 0.094). The 1-, 3-, 5-year overall survival rates of patients with stage N 1 and stage N 2-N 3 were 63.5%, 34.7%, 17.3% and 52.2%, 11.9%, 0, respectively, and there was no statistically significant difference in OS of both groups ( P = 0.083). The 1-, 3-, 5-year overall survival rates were 64.6%, 30.5%, 18.3%, respectively in radiotherapy group and 38.2%, 0, 0, respectively in non-radiotherapy group, and there was a statistically significant difference in OS of both groups ( P = 0.008); the progression-free survival in radiotherapy group was better than that in non-radiotherapy group ( P = 0.028). The 1-, 3-, 5-year overall survival rates were 70.8%, 35.5%, 21.3% and 33.3%, 0, 0 and 35.4%, 0, 0, respectively in concurrent chemoradiotherapy group, radiotherapy group and chemotherapy group, and there was a statistically significant difference in overall survival among three groups ( P = 0.004). The results of univariate analysis showed that radiotherapy ( χ2 = 7.112, P = 0.008) and concurrent chemoradiotherapy ( χ2 = 10.940, P = 0.004) were the main factors affecting the prognosis. Conclusions:Lymph node and distant metastasis could occur in esophageal carcinoma patients with stage T 1 and T 2. Radiotherapy can prolong the progression-free survival time and concurrent chemoradiotherapy could benefit overall survival of these patients.

BACKGROUND:IPS e.max Presshas an excelent biocompati bility and corrosion resistance, which obtains satisfactory clinical outcomes on dental veneers, inlay and onlay restorations. But little is reported on molar monolithic restoration by IPS e.max Presscrown.
OBJECTIVE:To evaluate the clinical effects of IPS e.max Press crown on molar repair after root canal therapy.
METHODS:Totaly 215 patients with 324 affected molars, including 88 males and 127 females, aged 22-58 years old, were enroled for repairing with IPS e.max Presscrown. Then the color, shape, fracture and edge coloring of the restoration, marginal discrepancy, secondary caries and gingival health status were assessed after a 3-year folow-up.
RESULTS AND CONCLUSION:During the folow-up, 324 dental restorations met the class A standards for color, marginal discrepancy, shape as wel as secondary caries. In addition,3restoration swere fractured, 14 restorations had margin coloring, and 8 restorations appeared to have gingival inflammation. More than 95% restorations were scored grade A. These results indicate that IPS e.max Press crown applied to molar repair after root canal therapy can achieve ideal outcomes.

Objective:To explore the protective mechanism of tea polyphenols (TP) on mouse oral cancer.Methods:A total of 50 mice were divided into control group, model group, TP group, Selisistat group, TP+ Selisistat group, with 10 mice in each group. The control group was gavaged with physiological saline, while the model group, TP group, Selisistat group, and TP+ Selisistat group were gavaged with 300 mg/L 4-NQO to establish a mouse oral cancer model. Physiological saline, 200 mg/kg TP, 0.01 mg/kg Selisistat, and 200 mg/kg TP+ 0.01 mg/kg Selisistat were gavaged respectively. The weight changes of each group of mice were compared; HE staining was used to observe the morphology of mouse oral tumor tissue; Enzyme linked immunosorbent assay was used to detect the levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in serum; Immunoblotting and immunohistochemistry were used to detect the expression of silencing information regulatory factor (Sirt1) and nuclear factor E2 related factor 2 (Nrf2) proteins in mouse oral tissues.Results:Compared with the control group, the model group mice had a decrease in body weight [(23.19±1.36)g], a decrease in serum SOD level [(91.64±8.75)U/ml], an increase in MDA level [(5.18±0.46)nmol/ml], a decrease in Sirt1 (0.38±0.05) and Nrf2 (0.36±0.05) protein expression in oral tissue, and an increase in Nrf2 acetylation level (0.84±0.11) (all P<0.05). Compared with the model group, the TP group mice had an increase in body weight [(25.28±1.25)g], elevated serum SOD levels [(121.24±10.68)U/ml], decreased MDA levels [(3.89±0.42)nmol/ml], increased expression of Sirt1 (0.61±0.09) and Nrf2 (0.58±0.06) proteins in oral tissue, and decreased Nrf2 protein acetylation levels (0.39±0.05); The Selisistat group mice showed a decrease in body weight [(21.41±1.07)g], a decrease in serum SOD levels [(72.16±7.43)U/ml], an increase in MDA levels [(5.87±0.41)nmol/ml], a decrease in Sirt1 (0.23±0.04) and Nrf2 protein (0.24±0.03) expression in oral tissue, and an increase in Nrf2 acetylation levels (1.12±0.14) ( P<0.05). The body weight [(23.32±1.27)g], serum SOD levels [(92.58±8.13)U/ml], and oral Sirt1 (0.41±0.06) and Nrf2 (0.38±0.05) protein expression in the TP+ Selisistat group mice were higher than those in the Selisistat group, while MDA [(5.11±0.38)nmol/ml] and Nrf2 acetylation levels (0.82±0.09) were lower than those in the Selisistat group (all P<0.05). Conclusions:Tea polyphenols can alleviate oral tissue damage and alleviate oxidative stress in mice with oral cancer, and their mechanism may be related to the upregulation of the Sirt1/Nrf2 pathway.

Objective:To discuss how to make the surgical strategy for tibial tubercle fracture associated with bicondylar tibial plateau fracture.Methods:Data of thirty-five patients of tibial tubercle fractures associated with bicondylar tibial plateau fractures who were treated from October 2014 to May 2018 were retrospectively analyzed. There were 26 males and 9 females with an average age of 37.6 years (range, 21-68 years). According to Schatzker classification in tibial plateau fracture, 16 cases were type V and 19 cases were type VI. According to the integrity of tibial tubercle fracture and cortical bone of the proximal tibia in bicondylar tibial plateau fracture, they were divided into four types: type A, tibial tubercle fracture fragment and cortical bone of the proximal tibia are both complete; type B, tibial tubercle fracture fragment is complete but cortical bone of the proximal tibia is comminuted; type C, tibial tubercle fracture fragment is comminuted but cortical bone of the proximal tibia is complete; type D, both of them are comminuted. The surgical approaches and fixation methods of all the tibial tubercle fractures were according to the four different types. There were 22 cases with type A and B that were treated via an anterolateral and a medial incision, 13 cases with type C and D were treated via an anterior midline and a medial incision. There were 4 cases belonging to type A fixed with lag screws singly, 18 cases with type B fixed with 1/4 tubular plates, 7 cases with type C and 6 cases with type D fixed by 1/4 tubular plates combined with lag screws.Results:Thirty-five patients were followed up for 16.8 months (range, 12-24 months). All fractures healed with an average time of 4.7 months (range, 3-6 months). Loss of reduction didn’t occur in 34 cases except one. According to Rasmussen radiographic evaluation, the average score was 14.1 (range, 10-18) and clinical outcomes were rated with excellent in 11 cases, good in 19, fair in 5. The excellent and good rate was 85.7% (30/35) . The mean Hospital for Special Surgery (HSS) scores of all cases were 86.8 (range, 64-98) and the functional scores were excellent in 22 cases, good in 10 cases and fair in 3 cases with the excellent and good rate of 91.4% (32/35) . Surgical complications included fat liquefaction in 2 cases, superficial wound infection in 1, loosening of implant in 1and traumatic arthritis in 1.Conclusion:This kind of tibial tubercle fracture associated with bicondylar tibial plateau fracture is rare and special. Therefore, the preoperative plan should be made by considering the morphological features of the tibial tubercle fragments and the cortical bone of the proximal tibia. The middle longitude approach is the best way to expose tibial tubercle fragments which should be fixed with 1/4 tubularplate and/or lag screws.