Dental caries is a major disease that threaten human’s oral healthy severely with the characteristics of high incidence, low rate of treatment and high rate of retreatment. At present, restorative treatment remains the main method for caries treatment. With the development of the Minimally Invasive Cosmetic Dentistry (MICD), reasonable application of various treatment technologies, maximum preservation of tooth tissues and realizing the maximization of treatment effects become problems that call for immediate solution in dental clinics. In addition, there still exist a large number of old restora-tions that need standard retreatments. Here, some difficulty influence factors of dental caries clinical treatment such as systemic and oral factors, individual caries susceptibility, treatment technologies and materials, retreatment methods of old restorations and technique sensitivity are analyzed, and corresponding processing strategies are also put forward.

The development of an expert consensus based on specific domestic situations will provide practical guidance to the efforts aiming at improving cleft care in China. The team approach of twenty-one cleft centers were pooled together, covering pre-surgical orthopedics, primary surgical repair, orthodontic treatment, alveolar bone graft, secondary deformity correction, palatal fistulae repair, the diagnosis and treatment of velopharyngeal incompetence, speech therapy, otitis media management, and skeletal deformity correction. Agreement was achieved among the authors concerning the application of critical surgical and non-surgical techniques. The ambition of this consensus is to introduce more clinicians to the revolution of sequential treatment of clefts, and form the basis for a more comprehensive cleft care manual in the future.

The development of clinical implant dentistry was intensively affected by dental implant design improvement and innovation, which brought about new concept, even milestone-like changes of clinical protocol. The current improve-ments of dental implant design and their clinical importance could be highlighted as followings: 1) The implant apical design influences the implant preliminary stability in immediate implant. The apical 3-5 mm design of implant makes implant stable in immediate implant, because this part would be screwed into alveolar bone through fresh socket, the other part of implant could not be tightly screwed in the socket because of smaller implant diameter. Implant apical form, screw design, self-taping of apical part would be essential for immediate implant. 2) The enough preliminary stability of implant makes immediate prosthesis possible. When osseointegration does not occur, the implant stability comes from a mechanical anchorage, which depends on implant form, screw thread and self-taping design. 3) Implant neck design may have influence for soft tissue recession in esthetic zone. The implant with large shoulder would not be selected for the esthetic area. The platform design may be more favorable in the area. 4) The connection design between implant and abutment is thought a very impor-tant structure in implant long-term stability. Moose taper and “tube in tube” were well documented structure design in 20-year clinical practice in Peking University. 5) In last 15 years, the plenty studies showed the platform design of implant had positive influence in implant marginal bone level. Whatever in single implant restoration or multi-implant prosthesis. 6) The digital technology makes clinical work more precise and high-tech. This would be a trend in implant dentistry. New generation of chair-side digital computer-aided design/computer-aided manufacturing makes immediate prosthesis without conventional impression possible. 7) New abutment design have changed clinical protocol greatly. The All-on-four concept and Weldone concept benefit both from the abutment innovation, which were large angulated abutment and special welding abutment materials.

Bisphosphonates (BPs), as potent drugs inhibiting bone resorption, have been widely used for treatment of several diseases. In recent years, dentists and oral and maxillofacial surgeons reported continuously increasing cases of bis-phosphonate-related osteonecrosis of the jaws (BRONJ). This disease is clinically characterized by exposed bones, formation of sequestrum, pain, and halitosis. Provided that pathogenesis of BRONJ is unclear, effective treatments for this disease are currently unavailable. Thus, prevention plays an important role in the management of BRONJ. This review summarizes research progress on pathogenesis, risk factors, clinical characteristics, treatment, and prevention of this condition.

Objective This study aimed to investigate the difference in salivary protease expression in patients with chro-nic periodontitis and normal individuals. Methods The stimulating saliva in patients with chronic periodontitis and normal individuals were collected. Protein chip technology was adapted to analyze salivary protease spectrum. Results Among the 34 proteases in the chip, disintegrin and metalloproteinase (ADAM)8, matrix metalloproteinase (MMP)-8, MMP-12, neprilysin/CD10, and uridylyl phosphate adenosine/urokinase showed a significantly increased concentration in the saliva of chronic periodontitis patients compared with those in the saliva of normal individuals (P<0.01). By contrast, the concentrations of ADAM9, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)1, ADAMTS13, cathepsin B, E, L, V, X/Z/P, kallikrein 6, 7, 11, 13,MMP-9, proteinase 3, presenilin-1, and proprotein convertase 9 sharply decreased (P<0.05). Conclusion The results demonstrated that protease spectrum in the saliva of chronic periodontitis patients and normal indi-viduals significantly differed. Analysis of salivary protease spectrum is a potential clinical method to examine, diagnose, and monitor chronic periodontitis.

Objective This study evaluated the effect of different mechanical-chemical surface treatments on the charac-teristics, microstructure, and composition of zirconia ceramics and on the zirconia-dentin adhesion. Methods The sintered commercial zirconia blocks (IPS e.max ZirCAD) were sectioned into 126 beams (6 mm×6 mm×5 mm) and randomly assigned to seven experimental groups (n=18). The zirconia block specimens were further treated as follows: (A) untreated, as control; (B) sandblasted with 50 μm Al₂O₃; (C) sandblasted with 50 μm Al₂O₃+30 μm silica powder; (D) sandblasted with 50 μm Al₂O₃+30% silica-sol coating; (E) sandblasted with 110 μm Al₂O₃; (F) sandblasted with 110 μm Al₂O₃+30 μm silica powder; and (G) sandblasted with 110 μm Al₂O₃+30% silica-sol coating. The surface roughness (R_a) of zirconia ceramics using X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) after seven surface treatments was analyzed. Seventy specimens of dentin surfaces were prepared. A dual-cure resin cement was applied into zirconia surfaces with its corresponding adhesive components to dentin. Shear bond strength (SBS) of each sample was measured using a universal testing machine. The data were analyzed by ANOVA using SPSS 17.0 software. Results Ra of zirconia were significantly different compared with the control group (P<0.05). The crystalline transformation from tetragonal phase to monoclinic phase was observed after surface modification. Monoclinic volume content of the heat-treated group was highest than that in other groups. The content of element Si in the heat-treated group was higher than that in other treatment groups accompanied by a decrease in elements Zr, Y, and Hf after being treated by two silica-coating methods. Air abrasion signifi-cantly increased the micro-cracks in the ceramic surface and caused the grain boundaries to disappear. A serious shrinkage of the thin silica film can be observed after sintering procedure. This process induced cracks and the film to strip away slightly from the surfaces of Y-TZP substrate. The SBS values from large to small were F and G groups, C and D groups, B and E groups (P<0.05), and control group (P<0.05). Conclusion Alumina sandblasting, silica powder abrasion, and silica-sol coating affect the surface morphology, structure, and composition of the tooth. This effect can also achieve the improved micro-mechanical interlocking or chemical bonding and finally increase the bond strength between zirconia and tooth. Alumina sandblasting followed by silica coating is an effective technique to increase the bonding strength between the zirconia ceramic and dentin.

Objective This study aimed to prepare oriented scaffolds derived from a cartilage extracellular matrix (CECM) and to investigate their physicochemical property and compatibility with adipose-derived stem cells (ADSCs). Methods A fresh porcine articular cartilage was cut into pieces. Cartilage nanofibers with diameters of 50-500 nm were collected through homogenization and centrifugation. These nanofibers were then decellularized by using Triton X-100 to produce 6% CECM. The oriented scaffolds derived from the nanoscale CECM were fabricated through unidirectional solidification and lyophili-zation. Afterward, these scaffolds were crosslinked. The physical and chemical performances and cell compatibility of CECM-oriented scaffolds were evaluated. Results The cross-sections of the scaffolds contained homogeneous reticular porous struc-tures with nanofibers on the walls of the pores, and the longitudinal sections revealed vertical tubular structures. Hematoxylin-eosin staining revealed that the scaffolds were red without blue. Toluidine blue, safranin O, and Sirius red staining showed positive results. The porosity, water absorption rate, and vertical compressive elastic modulus of the scaffolds were 95.455%±0.910%, 95.889%±1.071%, and (40.208±5.097) kPa, respectively. Conclusion The components of the oriented scaffolds derived from CECM are similar to those of native cartilage with favorable biocompatibility. The porous structures and sizes of the scaffolds are suitable for the adhesion, prolife-ration, and infiltration of ADSCs. The oriented scaffolds derived from CECM are relatively optimal for cartilage tissue engineering.

Objective This study investigated the effect of clock gene PER1 on the expression levels of other clock genes in clock gene networks in oral squamous cell carcinoma cells. Methods We used RNA interference mediated by short hairpin RNAs (shRNAs) to effectively knock down PER1 in SCC15 human oral squamous cell carcinoma cells. Flow cytometry was used to detect the degree of proliferation and apoptosis of the cells after PER1 knockdown, and quantitative real-time PCR was used to detect the mRNA expression levels of the clock genes CLOCK, BMAL1, PER1, PER2, PER3, DEC1, DEC2, CRY1, CRY2, TIM, CKIE, RORA, NPAS2, and REV-ERBA. Results The proliferation index of SCC15 cells increased significantly while the apoptotic index decreased significantly after PER1 knockdown (P<0.05). The mRNA expression levels of PER1, PER2, DEC1, DEC2, CRY1, CRY2, and NPAS2 markedly decreased (P<0.05) while those of PER3, TIM, RORA, and REV-ERBA markedly increased (P<0.05). By contrast, no obvious changes were observed in the mRNA expression levels of CLOCK, BMAL1, and CKIE (P>0.05). Conclusion The clock gene PER1 can regulate the expression levels of other clock genes in the clock gene networks; these genes include PER2, DEC1, DEC2, CRY1, CRY2, NPAS2, PER3, TIM, RORA, and REV-ERBA. PER1 gene thus plays an important role in the regulation of clock gene networks.

Objective Recombinant human leucine-rich amelogenin peptide (LRAP) was studied by cryogenic trans-mission electron microscopy (TEM); evaluation focused on its self-assembly and crystal growth in vitro. Methods Human LRAP was recombined through prokaryotic expression vector pCold-SUMO and transformed into Escherichia coli BL21plys to acquire purified proteins. Cryogen TEM recorded assembly and self-assembling of LRAP from pH 3.5 to pH 8.0, and the hydroxyapatite crystal growth in the mixture of LRAP protein solution and artificial saliva was observed using TEM and selected area electron diffraction. Results More than 90% purity LRAP was expressed, purified and identified as described in methods. LRAP linked into oligomers, nanospheres, nanochains, and microribbons, whereas pH value increased from 3.5 to 8.0. Mature hydroxyapatite crystal growth was guided in artificial saliva filled with calcium phosphate. Conclusion LRAP is simplified amelogenin functional domain and conserved the basic characters of amelogenin such as self-assembling and inducing crystallization along c axis. In the area of acellular synthesis of hydroxyapatite using extracellular enamel matrix protein, LRAP is one of candidate repair materials for irregular hard tissue defection.

Objective This study investigated the rapid response of osteoblasts, which were derived from low-magnitude high-frequency vibration (LMHFV). Refractory period-derived memory response was also observed. Methods MC3T3-E1 cells were incubated and received LMHFV stimulation (0.49 g, 40 Hz) for 30 min. After application of LMHFV, mRNA levels of earlier osteogenic differentiation markers Runt-related transcription factor 2 (Runx2), collagen typeⅠ(Col-Ⅰ), and alkaline phosphatase (ALP) were immediately detected by real-time fluorescence quantitative polymerase chain reaction in the absence or presence of antioxidant. Simultaneously, concentrations of mitochondrial reactive oxygen species (ROS) and average mito-chondrial length were also measured. Results Osteoblasts in the vibration group showed decreased gene expressions of Runx2, Col-Ⅰ, and ALP (P<0.01) and increased levels of mitochondrial ROS (P<0.01) and shortened mitochondria (P<0.01), whereas antioxidant treatment resulted in recovery from changes in the above indicators (P<0.01). Conclusion LMHFV can downregulate mRNA levels of early osteogenic differentiation markers, promote ROS generation, and mitochondrial fission.

Objective This study aimed to examine the complications of supratemporalis approach with scalp coronal incision for the treatment of orbital-zygomatic fractures. Methods A total of 206 patients with orbital-zygomatic fractures were treated with scalp coronal incision through the supratemporalis approach. The effects and complications of the treatment were analyzed. Results The degree of fracture of the 206 patients was successfully reduced. The facial morphologies and functions were improved. No facial nerve injury was observed in all of the cases. However, the following complications were noted: fossa introcession in 1 case, forehead scalp pain or paresthesia in 11 cases, incision infection in 1 case, subcutaneous hematoma in 1 case, incision scar in 5 cases, and alopecia in 3 cases. Conclusion The supratemporalis approach prevents facial nerve injury and does not increase the frequency of other complications. Therefore, this approach can be applied as a routine and safe procedure in clinical settings.

Objective The objective of this paper is to analyze the stress distribution in the deep wedge-shaped defective mandibular first premolars restored with different methods. Methods Three-dimensional finite element models of mandibular first premolar with deep wedge-shaped defect were created. The model, which was untreated after root canal treatment, served as the control group. Then, according to different treatment designs, four experimental groups were established as follows: resin filling (A), post restoration after resin filling (B), crown restoration after resin filling (C), and post and crown restoration after resin filling (D). Four different post materials were then chosen for establishing the subgroup models: fiber post (B1, D1), AuPd post (B2, D2), pure Ti post (B3, D3), and CoCr post (B4, D4). A force of 100 N was applied at a 30° angle on the buccal-inclined surface near the top of the buccal cusp. The maximum principal stress and Von Mises stress were investigated using finite element analysis software. Results 1) For the control group, the maximum principal stress and Von Mises stress of the residual dentine were the same as those of the tip of the defect. 2) Compared with the control group, the maximum principal stress and Von Mises stress of groups A, B, C, and D decreased greatly (P<0.05). The maximum principal stress and Von Mises stress of groups C and D with crowns were similar. The maximum principal stress and Von Mises stress of the post-dentine surface of groups B and D with fiber post were less than those in the cast metal post models (P<0.05). 3) The displacement of the buccal cusp of group A was similar to that of the control group (P>0.05) and larger than those in groups B, C, and D (P<0.05). Conclusion It is necessary for deep wedge-shaped defective teeth to be treated with full crowns, but a post is not necessary. If a post is used, fiber post with elastic modulus closer to the dentine is more suitable than metal post.

Objective To investigate the incidence of bifid mandibular canals (BMC), and analyze the types, courses, and anatomic features of the variant canals in the adult population in Sichuan Province. Methods Five hundred patients (1 000 hemimandibles) underwent cone beam computed tomography (CBCT) were included in this study. The incidence, bifurcate types and courses of the BMC were evaluated. Results The incidence of BMC was 13.8% (69/500) in the study, 9.2% in terms of total hemimandibles. The most frequently type was retromolar canals, followed by the dental and buccolingual type, meanwhile the lowest was the forward type. The mean diameter of the accessory canals was 0.90 mm and the mean length was 9.39 mm. Conclusion CBCT used in this study has shown that the incidence of BMC assessed by CBCT was significantly higher than panoramic radiography. Furthermore, CBCT can depict the position, course, size and the branches of the mandi-bular canals.

Objective This research estimated shear bond durability of zirconia and different substrates cemented by two self-adhesive resin cements (Clearfil SA Luting and RelyX U100) before and after aging conditioning. Methods Machined zirconia ceramic discs were cemented with four kinds of core material (cobalt-chromium alloy, flowable composite resin core material, packable composite resin, and dentin) with two self-adhesive resin cements (Clearfil SA Luting and RelyX U100). All specimens were divided into eight test groups, and each test group was divided into two subgroups. Each subgroup was subjected to shear test before and after 10 000 thermal cycles. Results All factors (core materials, cements, and thermal cycle) significantly influenced bond durability of zirconia ceramic (P<0.00 1). After 10 000 thermal cycles, significant decrease was not observed in shear bond strength of cobalt-chromium alloy luted with Clearfil SA Luting (P>0.05); observed shear bond strength was significantly higher than those of other substrates (P<0.05). Significantly higher shear bond strength was noted in Clearfil SA Luting luted with cobalt-chromium alloy, flowable composite resin core material, and packable composite resin than that of RelyX U100 (P<0.05). However, significant difference was not observed in shear bond strength of dentin luted with Clearfil SA Luting and RelyX U100 (P>0.05). Conclusion Different core materials and self-adhesive resin cements can significantly affect bond durability of zirconia ceramic.

Digital technology is a new trend in implant dentistry and oral medical technology. Stereolithographic surgical guides, which are computer-guided implant placement, have been introduced gradually to the market. Surgeons are attracted to this approach because of it features visualized preoperative planning, simple surgical procedure, flapless implant, and imme-diate restoration. However, surgeons are concerned about the accuracy and complications of this approach. This review aims to introduce the classification of computer-guided implant placement. The advantages, disadvantages, and accuracy of this approach are also analyzed. Moreover, factors that may affect the outcomes of computer-guided implant placement are deter-mined. Results will provide a reference to surgeons regarding the clinical application of this approach.

Drug-induced gingival overgrowth (DIGO) is characterized by fibrous gingival hyperplasia and increased gin-gival volume. DIGO is histologically associated with proliferation of cells and deposition of extracellular matrices, particularly collagen. Integrin α2β1 is related to collagen phagocytosis and involved in the occurrence and progression of DIGO. This paper reviews the progress of research on the relationship between integrin α2β1 and DIGO.

Dental caries and periodontal diseases are common chronic infectious diseases that cause serious damage to oral health. Bacteria is the primary factor leading to such conditions. As a dental plaque control method, chemotherapeutic agents face serious challenges in dental care because of the specific physiological and anatomical characteristics of the oral cavity. Nanodrug delivery system is a series of new drug delivery systems at nanoscale, and it can target cells, promote sustained-release effects, and enhance biodegradation. This review focuses on research progress on nanodrug delivery systems for pre-vention and control of dental caries and periodontal diseases.

We reported one case of a patient with Sjögren’s syndrome and dental implant. This patient was followed up for more than one year. The patient was diagnosed with Sjögren’s syndrome for 5 years and treated with long-term corticosteroid. Four implant-tissue interface hydrophilic implants were placed on 15, 16, 44, and 46 of the mandibular and maxillary areas. After the surgery was completed, the patient was treated with oral antibiotic and “shenggu pills” to prevent infection and glucocorticoid to manage Sjögren’s syndrome. Consequently, six implants were placed in other parts of the mandibular and maxillary areas. After more than one year of follow-up, the implants and prosthesis remained stable and had no complications. Cone beam CT reconstruction showed good implant-bone combination.