Periapical periodontitis of young permanent teeth has always been a difficult problem in clinical treatment. Regenerative endodontics is a new method for the treatment of periapical periodontitis of young permanent teeth in recent years. It can not only sterilize the root canal by irrigation, but also avoid mechanical preparation and guide the apical stem cells into the root canal, so as to promote the development of the root and achieve good clinical effect. Through the analysis and review of the relevant research on regenerative endodontics, this paper provides help for clinical selection of the best treatment.

Objective: To investigate the effect of iRoot BP Plus on the odonto/osteogenic differentiation and autophagy of bone marrow mesenchymal stem cells. Methods: BMMSCs were harvested by the whole marrow method. iRoot BP Plus conditioned medium was made by material evaluates and the optimal concentration of iRoot BP Plus conditioned medium was determined by western blot. ALP staining, qRT-PCR and western blot were used to investigate the odonto/osteogenic capacity of BMMSCs. The autophagy related makers wasere detected by western blot. Results: 0.2 mg/ml was the optimal concentration of iRoot BP Plus conditioned medium. When treated with 0.2 mg/ml iRoot BP Plus conditioned medium, the expression of odonto/osteogenic markers in BMMSCs was significantly higher than that in control group, and the ratio of LC3Ⅱ/LC3Ⅰupregulated while the protein level of p62 decreased. Conclusion: iRoot BP Plus can potentially promote the odonto/osteogenic capacity of BMMSCs through activating autophagy.

Objective To investigate the effect of high concentration of zoledronate on proliferation, apoptosis and osteogenic differentiation of healthy human periodontal stem cells. Methods Human periodontal ligament stem cells （hPDLSCs）were isolated from health tissues and exposed to zoledronate with different concentrations (0 μmol/L, 5μmol/L，10 μmol/L) in vitro. Cell proliferation ability was detected using CCK-8 kit and flow cytometry was applied to identity cell apoptosis. ALP staining and Alizarin red staining were used to evaluate the osteogenesis differentiation of hPDLSCs. Real-time PCR were used to measure the gene expression of COL1A1 and OCN and immunofluorescence was used to detect the levels of protein expression of COL1A1 and OCN. Osteogenesis was analyzed with ectopic osteogenesis in nude mice. Results Zoledronate inhibited proliferation of hPDLSCs in a dose dependent manner. Flow cytometry results indicated higher proportion of apoptosis cells in zoledronate treated groups. ALP staining and Alizarin red staining both revealed decreased osteogenesis differentiation ability in zoledronate treated groups. Significant down-regulation of the levels of mRNA expression and protein expression in COL1A1 and OCN were also found in zoledronate treated groups. Conclusion High concentration of zoledronate significantly inhibited the proliferation and osteogenic differentiation of hPDLSCs and induced their apoptosis.

Objective　 To evaluate the differences in the cytokine release in vitro and the degradation rate in vivo of concentrated growth factor (CGF) membranes for standardized protocol of CGF membrane preparation with three designed compression methods: dry gauze, a compressor and a special syringe. Methods Microsurface textures and fibrin densities of the compressed CGF membranes were examined via scanning electron microscopy and transmission electron microscopy. Cytokine release (TGF-β1, VEGF, PDGF-AB) and the degradation rate were analyzed with one-way ANOVA and Kruskal-Wallis H test by conducting enzyme-linked immunosorbent assay, haematoxylin-eosin and Mallory phosphotungstic acid-haematoxylin staining. Results No significant difference in the release of main cytokines and the degradation rate was noted amongst the three compression methods, although the surface topographies and fibrin densities of the three-group membranes were quite different. The main cytokines in vitro exhibited steady controlled release until the 33rd day, and the release amount did not decrease evidently at different time points. In vivo, all the fibrin membranes were degraded completely within 5 weeks. Conclusions No significant difference was found in cytokine release and degradability amongst the CGF membranes with different compression methods. The results provided theoretical basis for standardized protocol of CGF membrane preparation.

Objective　①To investigate the animal model establishment of maxillofacial gunshot wound and blast injury; ②To study the early treatment strategies of maxillofacial gunshot wound and blast injury. Methods Eight dogs (6 Chinese garden dogs and 2 Beagle dogs, 6 months old, male) were randomly divided into two groups: gunshot wound (A) group and blast injury (B) group. Before the injuries were performed, the protective devices for chest and abdomen and craniocerebral were made. Besides, CT scanning and 3D reconstruction were also conducted. Group A: Debridement or/and fracture external fixation treatment was performed according to the occlusal relationship changes resulted from gunshot; Group B: Multiple penetrating wounds in the maxillofacial soft tissue and a large amount of foreign body residual resulted from blast injury, and debridement treatment was performed. These wounds caused by gunshot were 5.8mm and 7.62mm high-precision sniper rifles, and the injury distance was 50 meters. The source of blast injury was a standard 200-gram TNT drug block containing 241g thin nails, the injury distance was 3 meters and 1 meter, respectively. According to injury conditions, the tracheal intubation and debridement and fracture external fixation treatments were performed immediately after the injury, at the same time, antibiotics were given to prevent infection. CT scanning and 3D reconstruction were also performed again 12 hours after operation. Results These models could stably simulate canine maxillofacial gunshot wound and blast injury. When the shooting distance was 50 meters, with the increase of the high-precision sniper rifle caliber (5.8mm to 7.62mm), the maxillofacial trauma was also changed from the comminuted fracture of the lower mandible with normal occlusion to a comminuted fracture of the upper and lower jaw with occlusal dislocation and soft tissue laceration. When the source of blast injury was kept to a 200-gram TNT drug block containing 241g thin nails, the jaw wounds of the experimental animals became more serious while the injury distance was narrowed from 3 meters to 1 meter. After the injury, the two groups of experimental animals were treated well as we previously planned. One dog with one-meter injury distance was dead 20 hours after the blast injury, but the rest were in good condition, which had good spirit, could move freely and eat and drink a little. And the surviving experimental animals were continued to be kept alive for four weeks. Conclusion The experimental injury model can achieve normal or disorganized occlusal relationship gunshot injury model and varying degrees of injury models for blast injury. After the injury, appropriate rescue measures, such as tracheal intubation, debridement, fracture external fixation, intravenous rehydration and anti-infection, should be taken immediately to maintain the normal shape and chewing function of the canine and keep the canine alive. Among them, early treatment plays a vital role in maintaining animals’ functions and lives.

Abstract： Objective To study the regulating protein of Wnt signaling pathway, DKK-1, inhibitor can be expressed in the dental follicle cells. To explore the specific expression mechanism of DKK-1 during osteogenic differentiation of dental follicle cells and the relationship between the formation of mature osteoblasts and eruption of the teeth. Methods The dental follicle cells were primarily cultured by digestion method and purified. The cells were divided into 2 groups: the control group was cultured in α-MEM medium, and the experimental group was cultured in α-MEM medium supplemented with osteogenesis induction. With increased of time after intervention two groups of cells were identified using immunocytochemistry. Western-blotting was used to evaluate the lever of cellular DKK-1、β-catenin and Runx2 protein. Results Compared with control group, the factors of DKK-1 expression of experimental group was significantly lower, the Western-blot results showed that the expression of DKK-1 were significantly lower than that of the control group, but the osteogenic factor Runx2 protein、expression was enhanced in the experimental group over time. Conclusions The expression of inhibitor DKK-1 a key regulator of Wnt pathway, is affected by osteogenesis induced differentiation in the dental follicle cells and reflect its inhibitory characteristics. To suggests the molecular basis of the formation mechanism for the development of Maxillary and mandible and eruption of the teeth.

Objective　 To study a method of making tunnel reduction and fixation of condylar neck and base fractures by using intraocular lens combined with small incision approach, and to observe its clinical effect. Methods　From January 2012 to January 2018, 30 cases of middle and low condylar neck fracture were selected for surgical treatment by using the ototragus combined with the submandibular small incision approach to create a tunnel. Results　1) Normal occlusal relationship was restored in 30 patients during the operation, and no occlusal disorder was found in postoperative review. 2) The anova of repeated measurement design data was used for the gap-mouth degree analysis, and the difference in gap-mouth degree was statistically significant (P<0.05) The reexamination was carried out before the operation and 1 to 12 months after the operation. The average interincisor distances were respectively (5.43averag) mm，(14.83verage) mm，(19.67verage) mm，(32.20verag) mm，(32.23verage) mm，and (32.4(verag) mm. The gap-mouth degree of the patients recovered gradually after surgery. 3) CT reexamination 1, 3, 6 and 12 months after surgery showed that the fracture healed in contrapuntal position, and there was no loosening, deformation or displacement of the titanium plate. 4) The scar was located in the ear and under the jaw, and the position was concealed. 5) One patient presented mild angulation after surgery, and was treated with neurotropic therapy. The symptoms disappeared 6 months after the surgery. Conclusion　 Intraocular lens combined with submandibular small incision approach for the treatment of condylar neck and base fractures has adequate exposure, accurate reduction, which achieves the goal of scar concealment, early mouth function training and recovery of occlusion, and effective protection for important anatomical structures like facial nerves, superficial temporal vessels and lateral pterygoid muscles. It provides a new reference for the choice of operative route of condylar neck and base fractures.

Objective To observe the changes of alveolar bone density in patients with chronic periodontitis before and after oral administration of vitamin D3 by cone beam computed tomography (CBCT). Methods Sixty 50- to 59-year-old patients with chronic periodontitis were selected and took vitamin D3 orally for 12 months. CBCT was used to measure the alveolar bone density at the proximal and distal alveolar septum and the alveolar ridge to the level of alveolar bone in the mesial, distal, buccal and lingual sides of left upper central incisors, canines, and first molars. Whether there was a statistical difference in alveolar bone density was evaluated after the oral administration of vitamin D3. Results There was no statistical significance in the difference of bone mineral density during the first observation after 6 months, but the difference of alveolar bone density during the second observation after 12 months was statistically significant (P＜0.05). Conclusion This study shows that short-term oral administration of vitamin D3 has significant difference in alveolar bone density in patients with chronic periodontitis.

Objective: to evaluate the effect of resin infiltration to prevent demineralization and caries formation after interproximal reduction. Methods: Patients after interproximal reduction procedures were treated by resin infiltration and fluoride varnish according to the manufacturer’s instructions. They were randomly divided into two groups following a split-mouth study. In group A, resin infiltration was applied in quadrants 1 and 3, and fluoride varnish was applied in quadrants 2 and 4. In group B, resin infiltration was applied in quadrants 2 and 4, while the fluoride varnish was applied in patients' oral quadrants 1 and 3. The patients were followed for twelve months, during which time their teeth were checked every three months. To investigate the differences in frequencies and ranks of demineralization and caries formation in different time between the two groups, two methods of visual inspection and radiological examination were carried out. Results: The results showed that there was no statistically significant difference between the two groups at the first 9 months. While, In the 12th month, the score of ICON group in visual inspection and radiological examination were significantly less than the control group. Conclusion: ICON resin infiltration can well prevent enamel demineralization and caries formation after interproximal reduction.

Abstract OBJECTIVE: This study was to investigate the effect of pre-formed muscle function appliance (T4K) on upper airway before and after orthodontic treatment of Class II mandibular retraction in the dentition period.METHODS:Twenty-three patients with Class II mandibular retraction who underwent treatment in the orthodontic department of Jiangsu Provincial Stomatological Hospital from February 2018 to August 2018, with an average age of 7.0 ± 1.04 years were used. The muscle function appliance (T4K) was used to correct the patient for 6 months. The cone beam CT was taken before and after treatment. The Dolphin 3D 11.9 software was used for 3D reconstruction. The statistical analysis was performed by SPSS 25.0 software. And after the measurement related indicators change. RESULTS: After 6 months of treatment, the upper airway total volume、Nasopharyngeal volume、Glossopharyngeal volume and pre-treatment results were excluded except for the pharyngeal segment.Statistically significant,the volume of the nasopharyngeal segment was the most significant; the minimum cross-sectional area of the upper airway nasopharyngeal segment and the pharyngeal segment was increased after treatment,The difference wasstatistically significant Conclusion:The maxillofacail function correction by pre-forming muscle function appliance (T4K) is beneficial to patients to get rid of bad oral habits, training the position of the tongue and using nasal breathing to restore the balance between the muscles of the mouth and the muscles. Proper growth with the airway

[Abstract] Objective To investigate the clinical effect of implant prosthesis in mandibular anterior teeth. Methods 60 patients with mandibular anterior teeth implanted in our hospital from February 2013 to August 2017 were selected as the research objects. According to the conditions and indications of the implant area, the control group and the experimental group were set up, 30 cases in each group. Immediate implantation was performed in the experimental group and selective implantation in the control group. The periodontal tissues of the two groups were compared after restoration [improved gingival sulcus bleeding index (mBI), probing depth (PD) and marginal bone resorption (MBL)]. The aesthetic effects of the two groups were evaluated by red aesthetic index (PES). The implant retention of the two groups was monitored one year after restoration. Results There was no significant difference in the mBI index between the experimental group and the control group at 1, 6 and 12 months after repair (p > 0.05, no statistical significance); there was no significant difference in the PD value between the experimental group and the control group at 1, 6 and 12 months after repair (p > 0.05, no statistical significance); the MBL value of the experimental group at 1, 6 and 12 months after repair (0.37±0.11 mm, 0.52±0.13 mm, 0.54±0.17 mm) was significantly lower than that of the control group. Group (0.65±0.12, 0.93±0.19, 0.85±0.33 mm), the difference was statistically significant (p < 0.05). The PES scores of (+ aesthetic effect in the experimental group (9.19±1.32, 9.86±1.02, 10.04±1.14) were significantly higher than those in the control group (7.27±1.63, 8.63±1.37, 8.02±1.25), and the difference was statistically significant (p < 0.05). There was no significant difference in the implant retention rate (93.75%) between the experimental group and the control group (93.55%) one year after restoration (p > 0.05). Conclusion Immediate implantation in mandibular anterior teeth can effectively reduce bone resorption and improve aesthetic effect, and has no significant impact on periodontal tissue and implant retention. It can be the preferred method for implant restoration in mandibular anterior teeth.

[abstract] Objective To investigate the effect of two kinds of restoration methods on masticatory efficiency of deciduous molars with large area defect. Methods 60 children with large area defect of deciduous molars were randomly divided into A and B groups. Group A was repaired with composite resin and group B was repaired with metal prefabricated crowns. The masticatory efficiency of the two groups after 6 months and 12 months was compared by X50 method. Results There was no significant difference in masticatory efficiency between group A and group B after 6 months (P > 0.05). The masticatory efficiency of group B after 12 months was significantly higher than that of group A (P < 0.05). Conclusion The masticatory efficiency of primary molars with large area defect restored by metal prefabricated crowns is remarkable, which is higher than that restored by composite resin, and can be accepted by children and parents. It is worth popularizing widely in clinic.

Abstract: Objective To investigate the prevalence of malocclusion in children aged 6 to 11 years old in 11 primary schools in Harbin,and assess the effects of feeding patterns,breast-feeding duration，bottle-feeding duration ,food habits and oral habits on the occlusal characteristics. Methods The occlusal characteristics of 12087 children were surveyed. The data of gender, age, feeding patterns, duration of breast-feeding and bottle-feeding, food habits and oral habits were collected by questionnaire. Results A total of 12,087 people were investigated, and the number of malocclusions was 7023, with an incidence rate of 58.10%. Statistical analysis found that breast-feeding, bottle-feeding; breast-fed for ＞ 6 months, bottle-fed for over 18 months; Preference for vegetables and fruits,Preference for cereals; lip habits , stretching chin, mouth breathing, bruxism, sleeping habits, family history were significantly correlated with the occurrence of different malocclusion (P > 0.05). Conclusion Children who had diffrent feeding patterns, breast-feeding duration,bottle-feeding duration ,food habits and oral habits were more likely to develop abnormal occlusal characteristics．

This article reports a case of periodontitis with drug-induced gingival hyperplasia after the use of cyclosporine. The gingiva returned to normal after a series of periodontal initial therapy along with gingivectomy and regular periodontal maintenance therapy. Drug-induced gingival hyperplasia has a close relationship with bacterial plaque. It needs to be emphasized that complete elimination of plaque and control of inflammation followed by thorough correct oral hygiene measures has a definitive significant effect on the gingiva.

Dental implant has become a common therapy for the patients requiring complete-arch rehabilitation with severe periodontitis. However, there are still some arguments on the timing of implant placement. This review will discuss the timing of complete-arch implant rehabilitation for the patients with severe periodontitis in four aspects: infection control, keratinized mucosa, pre-operative esthetic and function assessment and surgical guide template.

As a common intraoral bone donor site in clinic, mandibular ramus can effectively improve the small and medium-sized alveolar bone defects caused by various reasons in maxillofacial region. Based on the anatomy and characteristics of mandibular ramus, this paper discussed the clinical acceptability, potential bone supply，postoperative reaction and the possibility of secondary bone supply of mandibular ramus. And the measures to reduce postoperative adverse reactions were summarized.

Exosomes are small vesicles which can be secreted by most cells between 40-100 nm, which contain active proteins and RNA, have many physiological functions, and have some potential clinical application values in tumor biology, immune nervous system and tissue repair. Recent studies have shown that they are closely related to oral diseases. This paper reviews resent advances in exosomes in oral diseases.

The sagittal position of the maxillary central incisor determines the aesthetic appearance of orthodontic patients. In orthodontic clinical diagnosis and treatment, patients with maxillary protrusion need to be treated with a reduction of four premolars to maximize the adduction and adduction of the upper and lower anterior teeth to improve the lateral appearance and solve the problem of suddenness. Traditional orthodontic treatment can make the maxillary central incisor adduct 5.78mm, and implant anchorage can increase the maximal adduction of the maxillary central incisor to 8mm, but in the process of adduction of the maxillary anterior teeth, a few maxillary Incisors can invade an important anatomical structure of the maxilla, the incisive canal, which leads to complications such as root resorption and teeth loose. Therefore, this paper reviews the research progress of the relationship between the incisive canal and the position of the maxillary central incisor.