Abstract: Periodontal diseases arewidespread human chronic inflammatory diseases, and statistical data show that the incidence still remains high in China, partly due to the poor health consciousness. Periodontitis can threaten oral functions including chewing and pronunciation, as well as systemic health caused by periodontitisinduced chronic inflammation and immune responses, which suggests the significance of dental treatment on improving survival rates and quality of life. Currently, periodontal treatments are moving towards visualization, refinement and miniinvasion. In addition, research on susceptible subject identification, systemic risk assessment and regenerative repair are is also advancing persistently. In general, fundamental improvement of periodontal condition requires the awareness of oral health consciousness, reformation of national medicalpolicy and physicianpatient cooperation.

Objective　To compare the proliferation, osteogenic and dentinogenic differentiation ability of stem cells from apical papilla and periodontal ligament stem cells, this study provides a theoretical basis for the application of stem cells in root regeneration. Methods PDLSCs and SCAP were obtained by combining enzyme digestion method and tissue block method. The expressions of stem cell surface markers CD90, CD146 were detected by FACS. The proliferation abilities of PDLSCs and SCAP were evaluated by CCK-8 method. The osteogenic abilities of PDLSCs and SCAP were tested by alizarin red staining and quantitative real-time PCR. And the expressions of dentinogenic protein: dentin matrix protein-1(DMP-1), dentin sialophosphoprotein(DSPP) were detected by quantitative real-time PCR. Result FACS profiling showed that PDLSCs and SCAP were strongly positive for CD105、CD90 and CD146. The results of CCK-8 showed that SCAP could promote the proliferation of PDLSCs (P<0.05). The alizarin red staining showed that the SCAP of mineralized nodules increased . Quantitative real-time PCR results showed that the expression of osteogenic marker genes Cementum attachment protein(CAP), Osteopontin(OPN), Runt-related transcription factor 2(RUNX-2) in SCAP were significantly higher than PDLSCs(P<0.05), and the expression levels of DMP-1 and DSPP in SCAP were significantly higher than PDLSCs (P<0.05). Conclusion The apical papilla stem cells have stronger proliferation, osteogenic and dentinogenic ability than periodontal ligament stem cells.

Objective　To investigate the effect of fine polishing on the abrasion between natural tooth and zirconia, or cobalt-chromium alloy. Methods　The surface roughness value was measured to analyze surface roughness of zirconia, glazed-zirconia and cobalt-chromium alloy before and after fine polishing. The friction coefficient between restoration materials and natural enamel was measured, friction and wear experiment was carried out between natural tooth and three kinds of materials under presupposed condition, which simulated oral chemistry environment by artificial saliva and mechanical property by wear and abrasion test machine. Every sample was weighed pretest-posttest to calculate volume loss. Scanning electron microscopy was used to analyze surface characteristic of post-experiment natural tooth. Results　The roughness value of polished zirconia group(0.933±0.1862)μm was significantly smaller than ziconia group(2.350±0.327)μm without polishing(P=0.000).Polished glazed-zirconia group (2.300±0.8718)μm and glazed-zirconia group(4.200±0.1897)μm, polished cobalt-chromium ally group (0.250±0.083)μm and cobalt-chromium ally group (1.200±0.894)μm had the same result(P=0.000).The volume loss of natural tooth for polished zirconia group(6.067±0.9212)mg was significantly smaller than zirconia group(16.690±2.113)mg without polishing(P=0.001).Polished glazed-zirconia group(5.893±0.838)mg and glazed-zirconia group(14.016±0.063)mg(P=0.000), polished cobalt-chromium ally group(4.573 ±1.954)mg and cobalt-chromium group(11.433±1.087)mg(P=0.008) had the same result. The volume loss of restoration for polished zirconia group(0.300±0.010)mg was significantly smaller than zirconia group(0.800±0.010)mg without polishing(P=0.001).Polished glazed-zirconia group(0.456±0.055)mg and glazed-zirconia group(0.650±0.086)mg(P=0.031), polished cobalt-chromium ally group(10.236 ±0.357)mg and cobalt-chromium group(14.300±0.526)mg(P=0.000) had the same result. The friction coefficient between polished zirconia and natural tooth(0.068) was significantly smaller than that between zirconia and natural tooth(0.096)(P=0.001).Glazed-zirconia and cobalt-chromium ally had the same result(P=0.001). Conclusions　Fine polishing significantly reduce the roughness of restoration surface and the friction coefficient between restoration and natural tooth, so it can avoid severe tooth wear.

Objective To compare the adhesion ability of microorganisms to three different metal materials.Streptococcus mutans and Candida albicans were used in adhesion experiment in order to provide theoretical guidance for choosing the suitable clinical materials. Methods Three types of removable partial denture metal materials were selected, including Co-Cr alloy, Vitallium 2000 and pure titanium. 20 mm×10 mm×2.0 mm specimens of these dental materials were prepared, six test pieces in each material. Polishing was made to ensure that there was no obvious difference. Streptococcus mutans and Candida albicans, as experimental strains, were placed on suspension over plate and taken in culture for 48 hours, the amount of bacteria adhering to the specimen surface was assayed by means of clone forming unit(CFU) method after being eluted, shaked, and cultured. Results After 48 hours, the sequence of the adhesive capacity of the oral microorganisms on the surface of specimens was: Co-Cr alloy＞pure titanium＞Vitallium 2000(P＜0.05). Conclusion Compared with Co-Cr alloy and pure titanium, Vitallium 2000 candecrease the adhesion of microorganisms, and it is worth promoting and applying.

Objective　 To analyze the height of the alveolar bone, and the relationship between the root of maxillary posterior teeth and the maxillary sinus floor, to provide a reliable reference for clinical diagnosis and treatment. Methods　Five hundred adult patients referred to cone-beam computed tomography (CBCT) scans for medical reasons were selected for study. The height of alveolar bone and the shortest distance between maxillary sinus floor and root tip were measured. The relationship between the maxillary sinus wall and the roots of the posterior teeth was classified, including vertical and horizontal relationships. These data were grouped according to the teeth and age, and the differences in the teeth and age were analyzed. Results　 The height of the alveolar bone of the maxillary premolars was11.31±7.39 and 9.52±7.98mm, which was significantly higher than that of maxillary molars, and the height of the alveolar bone decreased with age. The average distance between the mesiobuccal root of the second maxillary molar and the maxillary sinus floor (1.73±3.63 mm) was the shortest among the maxillary roots. The average distance between the root of the first maxillary premolar and the maxillary sinus floor (9.53±5.79 mm) was the longest among the maxillary roots. The distance decreased with age. In the vertical relationship between the maxillary molar root and maxillary sinus floor, the percent of three roots not in contact with the floor was significantly higher than other categories. In horizontal relationship, the floor of maxillary sinus was most frequently observed at the level between the bifurcation and apices of roots. The relationship between root and maxillary sinus was more closely related with the increase of age. Conclusions　The relationship between the maxillary sinus floor and root is individually different according to the teeth and age. Using the CBCT can accurately analyze the anatomical structure of the maxillary posterior region, design the individually therapeutic schedules, and reduce the occurrence of the iatrogenic problem.

[Abstract]Objective:3D scanning young uighurs in XinJiang kashgar area normal tooth teenagers model,three dimensional measuring Bolton and Pont index,and to establish the region teenagers three-dimensional fang in the database.Method:select normal tooth model 191 (male 72, female 119),using the homemade lang cheng dl-100 in mouth scanner get three-dimensional digital model of three-dimensional reverse engineering software GEOMAGIC measure tooth crown width, width of dental arch,and the results analysis.Results:Bolton index to compare differences between men and women there is no statistical significance (P>0.05), between men's and women's jaw teeth quantity is highly related to the Pont index compared differences between men and women have statistical significance (P<0.05).Conclusion: Dentition index exists racial,regional, gender and other differences, should refer the standard of this region in the middle of the clinical application.

[Abstract] Objective: To investigate the differential distributions of five single nucleotide polymorphism (SNP) loci of RAGE gene in type 2 diabetes with chronic periodontitis (DM), chronic periodontitis (CP), and healthy controls among northern Chinese Han people, so as to study whether RAGE gene serves as a susceptible candidate gene for both diabetes and periodontitis. Methods: Utilized a flight-time mass spectrometer method to analyze five SNPs of 19 DM subjects, 22 CP subjects, and 54 healthy subjects. Results: The distributions of rs17846808, rs1800625, rs184003, rs2070600, rs3134940 polymorphisms demonstrated no significance among three groups. In DM group, subjects carrying rs3134940 A/A genotype had higher SBI than those carrying A/G+G/G genotypes. In CP group, subjects carrying rs1800625 (T/C+C/C) and rs3134940 (A/G+G/G) genotypes had significant higher loss of teeth. Conclusion: In the samples of this study, RAGE gene fails to demonstrate its potential to be a candidate gene for type 2 diabetes and chronic periodontitis susceptibilities. rs3134940 G allele may have some protective roles in the progression of type 2 diabetes with chronic periodontitis. On top of that, larger studies need to be included to draw any further conclusions.

Evaluate the possible effects of menopause on the severity of periodontal disease and bone loss, for considering the therapy of periodontal disease. Methods: 50 women with chronic periodontitis, oral and periodontal parameters including: plaque index, probing depth, bleeding on probing and attachment loss were recorded. Results: The mean age of this study was 53.9±3.5 year’s old. PD, CAL, PLI, BI index and alveolar bone defect were positively correlated with the time of menopause (P<0.001) were increasing with the increase of menopause. The alveolar bone density of patients with chronic periodontitis decreased with the increase of menopause time. The alveolar bone density was negatively correlated with the time of menopause (P <0.001). Conclusions: The time of Menopause does appear to significantly influence the severity of periodontal disease and bone loss. Our results suggest that poor periodontal status may be associated with low bone mineral density of postmenopausal women.

Abstract: Objective To evaluate the short-term efficacy of enhancing deficient interdental papilla of anterior teeth with hyaluronic acid gel injection. Methods 16 target sites with interdental papilla recession were treated in five female volunteers. Following local anesthesia, cross-linked sodium hyaluronate gel was injected into the base of every defective papilla. The injections were repeated twice three weeks and six weeks later. Papillary heights and lost papilla surface areas were calculated from digital clinical photographs taken at base line and 6-months after operation using image software Digimizer. The comparsions of the changes of papillary height and the lost papilla surface areas between baseline and postoperativetime points were statistically analyzed. Results The average difference in height of the target inderdental papilla between baseline and 6-month after operation was 0.62 mm. The percentage of the height change between baseline and postoperative visit was 27.3%. The average change of the lost papilla surface area was 0.67mm2. The mean percentage of area change was 50.9%. Differences between baseline and postoperative visit were statistically significant (p< 0.01). Conclusions Use of hyaluronic acid gel to treat interdental papilla recession resultes in significant improvement atfter 6 months. The long-term efficacy of an injectable hyaluronic gel toenhance papillary esthetics should be evaluated in an extensive randomized controlled trial.

Abstract： Objective To discuss the the clinical features treatment and prognosis analysis of cracked teeth. Methods: According to the degree of illness development, 190 cracked teeth were divided into normal cracked tooth pulp group (group A) including 64 teeth and dental pulp abnormal cracked tooth group (group B)including 126 teeth.According to the principle of treatment and the patient's own situation, different treatment methods were choosen, statistical analysis was carried out on the effect of 1 year after treatment. Results: The success rate of full crown restoration in group A was 78.9%, higher than the success rate of the occlusal adjustment and the tooth filling, difference was statistically significant( P﹤ 0.05). The success rate of full crown restoration in group B was 94.0%, significantly higher than the pure filling treatment success rate, the difference was statistically significant(P﹤0.05). Conclusion: It need early diagnosis and early treatment for Cracked teeth ,we must have accurate judgment of crack depth and scope.It can use full crown restoration for the maximum retention of teeth. Key words：tooth cracked; filling; crown

Objective To compare the effects of two ceramic veneer bonding methods on gingival health, the gingival retraction trauma and the mechanical gingival epithelium trauma, and to provide reference for clinical application. Methods Thirty-six symmetrical teeth after veneer preparation of 11 patients who were periodontally healthy were selected in this homologous pairing design. Teeth in one side were randomly chosen to be treated with retraction cord in cementing procedure and the other side with polishing bonding. The healthy adjacent teeth were chosen as the control group. After one week and two weeks after bonding, restoration teeth had a return visit. Plaque index (PLI), probing depth (PD) ,and Mazza index (MI)of the restoration teeth were measured after cementation, as well as the adjacent natural teeth. Differences in clinical parameters were analyzed with the Friedman signed ranks test and Wilcoxon signed ranks test (α=0.05). One year later, the pigmentation in margin of cementation and visual gingival recession were observed. Results The periodontal parameters were not statistically significant among the groups at two intervals except for the Mazza index(P=0.004), which increased in two groups after 1 week while there was no statistical significance(P=0.16) between cord group(1.00(0.75~1.00) )and the cordless group.( 1.00(1.00~2.00)). No obvious pigmentation in margin of the cementation and visual gingival recession was observed after one year. Conclusions Both the two techniques injure the gingival health by causing a temporary gingival inflammation which is indicated by Mazza index (MD)and can not be traced after 2 weeks. No statistical significance between the two techniques on gingival health can be measured in a short period.

Gingival recession is a common complication of orthodontic treatment, the main treatment of which is root coverage. The record of a patient with post orthodontic treatmen gingival recession, after subepithelial connective tissue graft combined with coronally advanced flap , got ideal root coverage, keratinized gingiva width and gingival thickness increased, to achieve a good clinical result.

Previous research showed that B cell mediated humoral immunity play a major role in the process of periodontitis. The antibody producted by B cells, in this process, not only neutralize antigen but also destroy host tissues because of antigen cross, molecular mimicry or epitope spreading. In addition, B cells secretes cytokines to regulate immune process, active osteoclast then lead to imbalance of bone formation and resorption. Furthermore, autoimmunity related to B cell also has something to do with periodontits. As a result, exploring B cells’ function and influence became the key of understanding periodontitis.

　Root canal sealer plays an important role in achieving an ideal obturation, which can penetrate into the irregularities that core materials are unable to enter. The clinical application of root canal sealers are varied, however, the sealing ability is considered to be a crucial factor for obturation. This paper comprehensively reviewed the sealing ability of different root canal sealers.

Transforming growth factor-β(TGF-β) is a multifunctional cytokine, which performs many crucial cellular functions in cell biological processes such as cell proliferation and differentiation, extracellular matrix synthesis and tissue repair. Recent studies have shown that TGF-βplays an important role in the development of the mandibular condylar cartilage. It mediates local functional stimulus in the remodeling of condylar cartilage and has a potential role in the development of TMJ osteoarthritis, protecting the articular cartilage. The purpose of this review is to discuss effects of TGF-βon the development, remodeling growth and degradation process of mandibular condylar cartilage.

Nerve growth factor (NGF) is widely distributed in the central nervous system and the peripheral nervous system. Many studies have found that NGF can promote blood vessel growth, wound healing, nerve system development and bone formation. Many factors can affect the stability of implant bone, among which implant surface property is the main one. In the process of implant?osseointegration, NGF can enhance the activity of osteocyte, promote osteoblast differentiation and mineralization, and improve the formation of peripheral nerve and blood vessel; it can also effectively promote healing of bone around the implant, and thus shorten the healing time of oral implant. This paper will review the role of NGF in promoting the?implant?osseointegration.

Chronic periodontal disease is not only accumulated periodontal support tissues, but also related to systemic diseases such as chronic kidney disease. Micro-inflammation is existed in patients with chronic kidney disease, and inflammatory factors are the main effect factor of micro -inflammation . Those factors such as IL - 6, CRP may be involved in the process and development of chronic periodontitis and chronic kidney disease. Take the mechanism of action IL-6, CRP in chronic periodontitis and chronic kidney disease as an example as follows to review briefly.

Stability, function, and esthetics are the goals of orthodontic treatment. When performing an orthodontic diagnosis and a treatment planning, facial esthetics become the key factor to be emphasized on. A pleasing profile look has been a great concern in most orthodontic patients. In nearly a century, due to an advancement of new technology, there is a remarkable change in the evaluation of orthodontic esthetics. This change has benefited the assessment of facial characteristics through various techniques, such as the use of anthropometry, picture analysis, computer-generated imaging, cephalometric analysis, etc. This paper will review on the longitudinal development in profile analysis at different times.