Dental Alloys ; Dental Implants ; Dental Materials ; Dental Prosthesis Design ; trends ; Humans ; Zirconium

To investigate the effect of NVP-DPP728, a DPP-Ⅳ inhibitor on new-onset diabetes and the autoimmune response in non-obese diabetic ( NOD ) mice. Diabetes could be reversed in 75% of NVP-DPP728 treated 20 NOD mice. In these 15 mice with remission, insulitis scores were significantly lower than those of the control group. The percentage of Tregs was increased in the thymus and celiac lymph nodes, plasma TGF-β1 and GLP-1 were also significantly increased ( P＜0. 01 ). NVP-DPP728 treatment may reverse new-onset diabetes in NOD mice by reducing insulitis and increasing Tregs.

Objective To investigate the protective effects of α-1 antitrypsin on human islets injured by protease released from pancreas exocrine cells. Methods ( 1 ) in vivo experiment. Parts of the cadaveric pancreas was digested with collagenase, islets were selected artificially, and pancreatic exocrine cells were collected. 8-9 weeks olds male BALB/c-Nu nude mice were induced into diabetic mice with STZ (240 mg/kg body weight, i. p) and randomly divided into two groups: the control group (n = 6), 250 islets were transplanted into left kidney subcapsule of diabetic nude mice; cotransplant group (n = 7), 250 islets and the equal volume of pancreatic exocrine cells were transplanted into different regions of left kidney subcapsule. Blood glucose level was monitored. Nephrectomies were performed after 28 days. The expression of anti-amylase antibodies in subcapsule was detected by using immunohistochemical staining. (2) Islets culture: Three groups were randomly set up. Group 1: purified islet group, 250 islets were incubated into a 6-well culture plate; Group 2: non-purified islet group, 250 purified islets and equal volume of exocrine cells were incubated; Group 3: nonpurified islet + Al AT group, 250 purified islets and equal volume of exocrine cells were incubated with α-1 antitrypsin added (0. 5 mg/ml). After 48 h, insulin content of islets in each well and trypsin concentration in the supernatant of each well were measured. Results 10000 islets were collected.After islets transplantation, the blood glucose levels in control and co-transplant groups were normal,but a delayed islet function in reversing diabetes was in the co-transplant group, and ehe mice in both groups became hyperglycemic after nephrectomy. A large number of anti-amylase antibody-positive cells were found in renal subcapsule in the co-transplant group while little seen in the control group.Insulin levels in the non-purified islet group were decreased as compared with purified islet group,those in the non-purified islet group + A1AT group were higher than in the non-purified islet group,but lower than in the purified islet groups. Trypsin concentration in the non-purified islet group was increased as compared with purified group, that in the non-purified islet group + A1AT group was lower than the non-purified islet group, but higher than in the purified islets group (all P＜0. 01).Conclusion Protease released from acinar cells during pancreatic digestion has detrimental effect on islet function after transplantation. Co-cultivation of islets and pancreatic exocrine cells with A1AT added can prevent islet cell damage caused by trypsin.

Objective: To evaluate the primary clinical outcomes of immediate provisionalization with a monolithic crown utilizing a novel chairside computer aided design and computer aided manufacture (CAD/CAM) workflow for single tooth immediate implant placement. Methods: This pilot study was a prospective within-subjects design. Thirteen consecutive patients were included and diagnosed with untreatable single incisor or premolar with fine general and local anatomical conditions. The trial was conducted at Department of Implantology, Peking University School and Hospital of Stomatology, Beijing, between January 2016 and June 2016. The teeth were extracted atraumatically and implants were immediately placed in the fresh sockets. Two screw-retained interim crowns were fabricated for the same site utilizing different workflows, a monolithic lithium disilicate (LS2) crown produced by CEREC (Sirona, Germany) chairside CAD/CAM system (CER group) and a manually fabricated resin crown utilizing conventional workflow (CONV group) respectively. The patients were blinded to the group allocation of the two interim crowns. After the clinical try-in for both crowns in a randomized sequence, the patients' level of satisfaction was assessed with a virtual analogue scale (VAS) questionnaire. The restorations chosen by patients themselves were seated in the implants by one experienced prosthodontist. The accuracy, aesthetic effect and clinical time consumption of both groups were compared. Statistical analyses were performed with the Wilcoxon signed rank test. Results: All patients were treated with atraumatic tooth extraction, immediate implant placement using flapless surgery and immediate provisionalization in a single visit. The interim crowns of both groups could be fitted with or without slight adjustments. For each patient, the interim crown of CER group was chosen to be seated with a relatively higher VAS result. The white esthetic score (WES) results demonstrated no statistically significant difference between CER group (7.5±1.1) and CONV group (7.9±0.9) (P>0.05). The mean total work time was significantly different resulting in (131.9±5.0) min for CER group and (205.2±6.3) min(P<0.05). The major difference lied in the laboratory work time, resulting in (113.5±6.3) min for CER group which was significantly shorter than (185.6±6.6) min for CONV group. As for impression taking time, the CER group (7.5±0.8) min was significantly shorter than CONV group (11.7± 1.1) min (P<0.05). However, analysis for clinical adjustment time showed a significantly longer time for CER group [(11.0±2.1) min vs (8.0±2.8) min, P<0.05]. After 3-6 months of observation, the overall survival rate was 100%. Screw loosening occurred in 4 patients and was tightened again. No other major complication soccurred. Conclusions The full digital workflow utilizing CEREC chairside CAD/CAM system to fabricate interim crowns after immediate implant placement in one single visit was feasible. It was more time-efficient and could effectively shorten the laboratory work time compared to the conventional workflow. Patients demonstrated high satisfaction and there was no statistical difference in WES results compared to the conventional workflow. Favorable clinical outcomes were gained in this short-term follow-up study.

Objective: To establish a quantitative three-dimensional method based on intraoral scan and apply it to evaluation of the facial soft tissue contour alterations following single immediate implant and immediate provisionalization (IIPP) in central incisor via intraoral scanning. Methods: This study was a prospective clinical study. The trial was conducted at Department of Implantology, Peking University School and Hospital of Stomatology, from January 2016 to September 2017. Twenty-nine eligible consecutive patients (15 women, 14 men) with a mean age of (34.3±12.0) were included and received immediate replacement of the failure maxillary single central incisor. A screw-retained immediate restoration was delivered for each patient. At 6-month follow-up, impression was taken and a screw-retained permanent restoration was performed for each patient. The anterior maxillary region was scanned by an intraoral scanning system at pre-surgery and 1-year follow-up. The Standard Tessellation Language (STL) files were output to a dedicated software and superimposed. Mid-facial recession and gingival zenith symmetry at 1-year follow-up were measured in the digital models. Three-dimensional configurations of the contour change volume were calculated and reconstructed for visual analysis. Furthermore, the following parameters were used to analyze the reconstructed volume: mean contour change in thickness (△d), mesio-distal width (D_W), coronal-apical height (D_H), contour change at 0, 1, 2, 3, 4, 5 mm apical to the free gingival margin on the implant site. Results: Twenty-seven out of twenty-nine enrolled patients were finally available for analysis. At 1-year follow-up, the mid-facial mucosa level at implant site was (0.23±0.39) mm apical to the gingival zenith of the contralateral tooth. In general, a contour collapse was found in every patient. △d, D_W and D_H of the collapsed volume were (0.62±0.22), (11.03±1.74) and (6.82±1.52) mm, respectively. Contour change at 0, 1, 2, 3, 4, 5 mm apical to the free gingival margin on the implant site were (0.54±0.48), (0.87±0.62), (1.03±0.46), (0.96±0.52), (0.90±0.52), (0.89±0.57) mm. Conclusions The described quantitative measurement based on intraoral scan can be an effective method for assessment of soft tissue contour changes. At 1 year following single IIPP treatment in maxillary incisor, free gingival margin is stable, with only mild recession. The mean level of the facial soft tissue contour collapse is 0.62 mm.