The target restoration space (TRS) is a required tooth space that should be occupied by an esthetically formed and optimally functioned crown, veneer, or other fixed restoration. It can be either internal of or external of a tooth. Since minimal invasive can’t be achieved without a minimal TRS, a precise preparation of slightest damage should conform to the transfer guide based on TRS. This paper introduces the concept, design of TRS, explains how it can be applied in tooth preparation, and helps to better understand a precise and minimal invasive tooth preparation technique.

Coronal restoration of endodontically treated teeth may be viewed as one of the main parameters that influence the outcome of endodontic treatment. The purposes of restoring endodontically-treated teeth include preventing recontamination of the root canal system and periapical area, replacing the compromised dental hard tissue, restoring the coronal morphology and function, providing necessary strength for the restoration/tooth complex for functional stress, and avoiding crown and/or root fracture. This article reviewed recent researches on the restoration of endodontically treated teeth, provided evidence for clinical practice on topics as when to restore them, basic principles to be considered during treatment planning, and specific restoration options for both anterior and posterior teeth under different functional occulsal load conditions. Several issues should be taken into account during the decision making process, such as remaining tooth tissue, functional masticatory forces, comprehensive oral rehabilitation, and esthetic requirements.

Objective To explore the efficacy of optical coherence tomography (OCT) in imaging and quantitatively evaluating early enamel caries and provide experimental evidence for the clinical diagnosis of early caries. Methods The smooth surface of bovine teeth showing early artificial caries and demineralization changes was scanned by an all fiber-based OCT for images and optical profiles, which were compared with images from a polarized light microscope (PLM) and mineral loss from an atomic absorption spectrometer. Data were analyzed by paired-sample t-test and Pearson correlation analysis using SPSS software. Results The images of enamel with early caries and demineralization from OCT coincided with those from PLM. The integrated reflectivity loss in the early caries group was significantly lower than that in the demineralized group (P<0.05), whereas no significant difference in demineralized depth was found between the two groups (P>0.05). A linear correlation was observed between integrated reflectivity loss and mineral loss (P<0.05). Conclusion OCT can be used to nondestructively and accurately image early caries and quantify lesion extent and degree, suggesting the extensive use of this approach in the clinical diagnosis of early caries.

Objective This study investigates the immune status of T helper (Th) 17 cells in mice with periodontitis. Methods Seven-week-old C57BL/6 female mice were randomly divided into the control and periodontitis groups. Each group comprisedfour mice. Experimental periodontitis was induced in mice by oral infection with Porphyromonas gingivalis in the periodontitis group. Phosphate-buffered saline solution was used in the control group. All mice were sacrificed 4 weeks after the last P. gingivalis infection. CD4+ retinoid-related orphan receptor (ROR) γτ+ (Th17) cells were analyzed by flow cytometry. The protein expression of Th17 cell-related cytokine interleukin (IL)-17A was detected by enzyme-linked immunosorbentassay (ELISA). Results Flow cytometry showed that the percentage of CD4+ RORγτ+ (Th17) cells in all CD4+T cells and the cell number in gingival tissues, cervical lymph nodes (CLNs), and the peripheral blood obviously increased (P<0.01) in the periodontitis group. ELISA showed that compared with the control group, the periodontitis group exhibited an obvious increase in the protein expression of IL-17A (P<0.05). Conclusion Th17 cell-mediated cell response is enhanced, and the gingival tissues, CLNs, and the peripheral blood are probably the main locations of Th17 cell-mediated cell response during the development of periodontitis.

Objective To investigate the functions of human periodontal myofibroblast (MFB) in vitro. Methods Human periodontal fibroblast (hPDLFs) was cultured and induced to MFB by transforming growth factor-β1 (TGF-β1). MFB was denoted as the experimental group, whereas the hPDLFs was the control group. The groups were continuously cultured and harvested at 0, 12, 24, 48, and 72 h. The MFB marker α-smooth muscle actin (α-SMA) was examined by immunocytochemistry. The expression of fibronectin (FN) between MFB was examined by immunocytochemistry to detect the MFB contact relationship. The mRNA expression levels of α-SMA, collagen (Col )Ⅰ, and Col Ⅲ were measured by reverse transcription-polymerase chain reaction (RT-PCT) to analyze extracellular matrix secretion. The protein expression levels of α-SMA and Col Ⅰ were also assessed by Western blot. Results The experimental group had significantly higher α-SMA expression than the control group at 0 h (P<0.001). A positive expression of FN was found between MFB. The experimental group had significantly higher expression levels of Col I and Col Ⅲ than the control group at 24 h (P<0.001). Conclusion Human periodontal MFB presents a continuous, high expression of α-SMA. MFB could interact through FN. MFB is significantly capable of extracellular matrix secretion.

Objective This study explores the effects of different fibrin glue combination modes on the survival, proliferation, and apoptosis of dental follicle cells (DFCs), as well as to evaluate the feasibility and effectiveness of fibrin glue as transplantation material. Methods The membranes of surviving DFCs were marked using 3,3’-dioctadecyloxa carbocyanine perchlorate (DIO), and the cell number was counted by using ImageJ2x software. The apoptotic cells were marked with prodium iodide (PI). Results Compared with that of the 3D-2 and 2D-1 groups, the degradation speed of the 3D-1 group was the slowest. DFCs could survive and grow well in fibrinogen with a concentration of 15 mg•mL-1 supplemented with thrombin with a concentration of 2 U•mL-1. In particular, the 3D-1 combination mode was significantly conducive to cell proliferation and stretching. Conclusion Fibrin glue can be used as an effective cell transplantation material. The different combination modes have certain effects on cell proliferation. The 3D-1 combination mode is more conducive to the survival and proliferation of DFCs than other modes.

Objective To investigate the effects of anti-infection treatment on the expressions of antigen-presenting-related membrane-surface molecules HLA-DR and CD86 in dendritic cells (DCs) in rabbit buccal VX2 squamous cell carcinoma tissue complicated with local inflammation. Methods Rabbit buccal VX2 squamous cell carcinoma with local inflammation models that were established by inflammation was induced by inoculation VX2 tumor, mechanical trauma, and drinking of milk with high sugar viscosity. The animals were divided into four groups. Group A (n=12): rabbit buccal VX2 squamous cell carcinoma with local inflammation, procaine penicillin was intramuscularly given, and tinidazole tablets were given by gavage for three consecutive days. Group B (n=12): rabbit buccal VX2 squamous cell carcinoma with local inflammation, normal saline was intramuscularly given, and aspirin were given by gavage for three consecutive days. Group C (n=12): rabbit buccal VX2 squamous cell carcinoma with local inflammation, normal saline was given intramuscularly and by gavage for three consecutive days. Group D (n=10): rabbit buccal VX2 squamous cell carcinoma, normal saline was given intramuscularly and by gavage for three consecutive days. All the rabbits were sacrificed for collection of tumor specimens, and the expression levels of membrane-surface HLA-DR and CD86 in DCs of tumor specimens were detected viaflow cytometry. Results The positive expression rate of HLA-DR and the double positive expression rate of HLA-DR and CD86 were group A> group D> group B> group C. The positive expression rate of CD86 were group A> group D> group B and group C (P< 0.05). Conclusion Anti-infection treatment significantly increased the expressions of HLA-DR and CD86 in DCs of rabbit buccal VX2 squamous cell carcinoma tissue complicated with local inflammation.

Objective To investigate evidence supporting whether ultrasonic irrigation as a supplement is more effective than syringe irrigation in root canal cleaning. Methods An electronic search was conducted in PubMed, Embase, Web of Science, Cochrane Library, ProQuest Dissertation and Theses, Database for Chinese Technical Periodicals, China National Knowledge Infrastructure, Wanfang Database, and Chinese Biomedical Literature Database. Studies were retrieved from January 1, 1985 to March 1, 2014. The Chinese journals on stomatology and the bibliography of all relevant articles were manually searched. Relevant clinical randomized controlled trial (RCT) and clinical controlled trial (CCT) were selected. Two investigators evaluated the risk of bias of the included trials in accordance with Cochrane risk of bias assessment tools and collected data of included studies. Meta-analysis was then performed in RevMan 5.2. Results Nine articles that satisfied the eligibility criteria were included in this Meta-analysis. Seven studies showed low bias risk, and the remaining studies exhibited moderate bias risk. Histological results showed that ultrasonic irrigation supplement could significantly improve canal and isthmus debridement at the apical area (P<0.01). Antibacterial efficacy was evaluated by bacterial culture (P=0.26) and polymerase chain reaction (P=0.99) methods, no significant differences in antibacterial efficacy were observed. Conclusion Ultrasonic irrigation supplement is more effective than syringe irrigation in root canal debridement at the apical area. However, antibacterial efficacy is not statisti-cally significant.

Objective To compare the sedative effects of different doses of dexmedetomidine (DEX) and midazolam (MDZ) in dental implant surgery. Methods Sixty patients undergoing dental implantation were selected and divided randomly into six groups (10 in each group). In group 1 (G1), a highdose of MDZ alone was administered intravenously. In group 2 (G2), a relatively low dose of MDZ and DEX was administered intravenously. In group 3 (G3), a highdose of MDZ and DEX was administered intravenously. In group 4 (G4), a lowdose of MDZ and a highdose of DEX were administered. In group 5(G5), a highdose of MDZ and a low dose of DEX were administered. In group 6 (G6), a highdose of DEX alone was administered intravenously. Blood pressure (BP), heart rate (HR), and arterial oxygen saturation values were measured. Sedation was assessed by determining the Ramsay sedation scores(RSS) during infiltration anesthesia (T1), incision (T2), cutting (T3), and suturing (T4). Before discharging from the hospital, patients were asked if they remembered the T1 to T4 procedures. The visual analogue scale (VAS) and the degree of patient satisfaction were assessed at the same time. Results In T1 to T4, the systolic blood pressure (SBP) in G3 was the lowest and was significantly different from that in G1 and G2 (P<0.05). In G1, the SBP was higher than that in G6 at the T3 and T4 points (P<0.05). HR was below the preoperative (P<0.05) in the G3 only. RSS was the lowest in G1 during the whole procedure. In G2, most patients obtained scores of 2–3. In G3, sedation was deeper, had more cases of up to 5. In G4, most patients obtained scores of 3–4. In G5, some patients had a score of up to 5. The RSS in G6 was lower than that in G3 and G4 or G5 in T1 to T2, closer to G4 in T2. An evaluation of the VAS and the degree of patient satisfaction did not show any differences among the groups. Conclusion The combination of DEX and MDZ is superior to a single intravenous injection. Low-dose MDZ combined with high-dose DEX achieved the highest quality of sedation in this study.

Objective The purpose of this study is to analyze the incidence and the type of the bifid mandibular canal (BMC) by using cone beam computed tomography (CBCT) images. Methods A total of 216 patients (104 female and 112 male) who underwent CBCT were included in this study. The CBCT images were evaluated for the incidence and the type of the BMC. Results BMC was observed in 39 (18.06%) of 216 patients and 50 (11.57%) of 432 sides, female 18 (17.31 %) and male 21 (18.75%). BMC were classified into four types: type Ⅰ 17 sides (3.94%), type Ⅱ 11 sides (2.55%), type Ⅲ 20 sides (4.63%), and type Ⅳ 2 sides (0.46%). Conclusion BMC is detected at a high rate by using CBCT. When doctors perform surgical procedures in the mandible, they should pay attention to the anatomical variations of BMC of the mandibular canals.

Objective This study investigates the effect of temporomandibular joint osteoarthritis (TMJOA) on different stages of condylar three-dimensional position and provides a theoretical basis for clinical application. Methods The cone beam computed tomography (CBCT) images of 108 TMJOA patients were analyzed and divided into four stages based on the stage standard of osteoarthrosis X-ray performance proposed by Xuchen Ma in 2005. A total of 28 defect-free temporomandibular joint disorders were used as the control group. Differences in condylar position and condylar axis horizontal angle were evaluated and compared. Results No significant differences were found in terms of sagittal relationship, but condylar axis horizontal angle showed a significant difference (F=3.872, P=0.005). The horizontal angle values of stage 1 in the TMJOA group were lower than those in stages 2 and 3 (P=0.027, P=0.000), whereas the horizontal angle values of stage 2 and control groups were lower than those of stage 3 group (P=0.004, P=0.047). Conclusion Condylar horizontal angle differed in each stage of TMJOA, but no significant difference between the parasagittal positions of the condyles was observed in each stage.

Objective To study the anti-halitosis effect of sugar-free chewing gum through their influence on odor induced by cysteine. Methods Ten volunteers were randomly divided into the treatment group and the untreated group; each group consisted of five volunteers. All volunteers consented to participate in a test in which breath odor was induced by cysteine. After the test, the treatment group chewed sugar-free chewing gum for 1 min, whereas the untreated group did not undergo any treatment. The effectiveness was determined by the percent reduction of H2S, CH3SH, and (CH3)2S response after thevolunteers chewed gum for 1, 10, and 20 min. Results At 1, 10, and 20 min, H2S of the treatment group was reduced by 82.68%, 92.27%, 97.47%, respectively, CH3SH was reduced by 65.49%, 73.79%, and 82.89%, respectively, and (CH3)2S was reduced by 60.45%, 73.82%, and 59.72%, respectively. The differences between the two groups at different times were significant (P<0.05). Conclusion Chewing gum can effectively inhibit cysteine-induced odor.

Objective To investigate the quality of life of cleft lip and/or palate children’s parents and discuss the factors to provide the oretical basis for improving the quality of life of these parents and promoting the healthy growth of children with cleft lip and/or palate. Methods A total of 115 parents whose children had cleft lip and/or palate surgery treatment were selected as the experiment group, and another 198 parents (with healthy children having a similar age with those in the experiment group) as the control group. The experiment group was divided into three subgroups according to different types of cleft lip and/or palate: cleft Lip (CL), cleft palate (CP), cleft lip and palate (CLP). The experiment group and the control group were both divided into four subgroups according to age:0-1, 1-3, 3-6 years old, and more than 6 years old. The experiment group and the control group were both divided into three subgroups according to education: junior middle school and the following, high school and technical secondary school, junior college degree or above. The GQOLI-74 scale was selected to assess the experiment group and the control group. SPSS 16.0 software was used to analyze data. Results 1) The experiment group had no significant difference with the control group in terms of the overall score and the scores of various children ages. 2) The scores of every item had no significant difference in CL, CP, CLP subgroup (P>0.05). 3) The quality of life scores and scores of psychological function dimension and social function dimension of parents with 3-6 years old patients were obviously lower than those of parents with more than 6 years old patients (P<0.05). The scores of social function dimension of parents with 0-1, 1-3, 3-6 years old patients were obviously lower than those of parents with more than 6 years old patients (P<0.05). The other items had no significant difference. 4) The scores of material life dimension and social function dimension of parents with junior college degree or above were higher than those of parents with junior middle school degree and the following (P<0.05). The scores of social function dimension of parents with high school and technical secondary school degree were higher than those of parents with junior middle school degree and the following (P<0.05). Conclusion No difference was observed in the quality of life between cleft lip and/or palate children’s parents and normal group. The parents with the low age children with cleft lip and/or palate and low-levels of education need more help and support to improve quality of life.

Objective This study aims to determine the awareness oral medical interns about occupation safety protection of knowledge and to present a scientific basis for perfecting the occupation safety education system and standard protection behavior. Methods A self-designed questionnaire that used a retrospective questionnaire survey on 425 stomatological interns, scoring, and statistical analysis of the survey were performed. The questionnaire included occupation safety prevention knowledge, behavior cognitive, and protective behavior, among others. Results The questionnaire recovery rate was 100%, and the average scores of the prevention knowledge and behavior cognitive were 4.55±0.91 and 4.40±1.05, respectively. More than 90% interns can conduct the conventional protection, and less than 40% can perform special protection. For the item“occupation safety protection knowledge”, the scores of three grade Ⅲ hospitals were higher than that of stomatological hospitals and second level of first-class hospitals; the difference was statistically significant (P<0.001). For the items “behavior cognition” and “protective behavior”, the scores of the second level of first-class hospitals were lower than those of grade Ⅲhospitals and stomatolgical hospitals (P<0.001). The second level of first-class hospitals was relatively poor in safety protection knowledge, behavioral cognitive, and protection behavior. The average score was higher for than for boys in the three contents, and the average score of interns accepting pre-job training was higher than those rejected; the difference was statistically significant (P<0.001). Conclusion The occupation safety knowledge of oral medical interns is not sufficient, and the protective behavior is poor. Schools and hospitals should strengthen the intern occupation safety and protection education and improve the status of occupation safety behavior.

Objective To analyze the status and characteristics of dental manpower in the center for disease controls (CDC) in Sichuan Province and to provide more evidence for strengthening the oral healthcare workforce in the CDC system. Methods A mass survey on dental manpower was made in CDCs in Sichuan Province through questionnaire investigation. Data were collected and entered with the Epidemiological Dynamic Data Collection (EDDC) platform and analyzed with SPSS 13.0 software. Results Sichuan Province had 0.15 hospitals providing oral health services and 0.38 dentists on average per 10 000 people. About 65.53% (135/206) of the CDCs had one department responsible for the oral health service. However, oral health care personnel comprised only 2.23% (237/10 624) of the personnel of the whole CDC system. About 64.67% (119/184) of county CDCs and 47.62% (10/21) of city CDCs knew well the dental health status of local residents. Less than 5% of the CDCs used the data and assisted in the policy making of public health administrators. Conclusion The dental care personal deficit exists in the CDC system in Sichuan Province. The distribution and composition of dental manpowerare not reasonable. The oral health service ability of CDCs in Sichuan Province should be strengthened and improved.

Objective The aim of this study is to analyze the three-dimensional crystal structure of SMU.2055 protein, a putative acetyltransferase from the major caries pathogen Streptococcus mutans (S. mutans). The design and selection of the structure-based small molecule inhibitors are also studied. Methods The three-dimensional crystal structure of SMU.2055 protein was obtained by structural genomics research methods of gene cloning and expression, protein purification with Ni2+-chelating affinity chromatography, crystal screening, and X-ray diffraction data collection. An inhibitor virtual model matching with its target protein structure was set up using computer-aided drug design methods, virtual screening and fine docking, and Libdock and Autodock procedures. Results The crystal of SMU.2055 protein was obtained, and its three-dimensional crystal structure was analyzed. This crystal was diffracted to a resolution of 0.23 nm. It belongs to orthorhombic space group C2221, with unit cell parameters of a=9.20 nm, b=9.46 nm, and c=19.39 nm. The asymmetric unit contained four molecules, with a solvent content of 56.7%. Moreover, five small molecule compounds, whose structure matched with that of the target protein in high degree, were designed and selected. Conclusion Protein crystallography research of S. mutans SMU.2055 helps to understand the structures and functions of proteins from S. mutans at the atomic level. These five compounds may be considered as effective inhibitors to SMU.2055. The virtual model of small molecule inhibitors we built will lay a foundation to the anticaries research based on the crystal structure of proteins.

Objective To compare the protein profiles between decapeptide-treated and untreated planktonic cells of Streptococcus mutans (S. mutans) by differential proteomic analysis to determine and identify the key proteins. Methods In our previous study, we investigated decapeptide (KKVVFKVKFK–NH2), which was a novel adenosine monophosphate. Compared with other oral pathogens tested, decapeptide had a preferential antibacterial activity against S. mutans. It also inhibited S. mutans biofilm formation and reduced the one-day developed biofilm. In the present study, we first synthesized decapeptide, and then compared the protein profiles between decapeptide-treated and untreated planktonic cells of S. mutans by twodimensional gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. We also verified different expressions of key protein enolase in the protein level. Results The results showed that decapeptide altered the protein expression of planktonic S. mutans. These proteins were functionally involved in carbohydrate degradation by glycolysis, protein folding, conjunction, transport, translation, adenosine triphosphate binding, protein binding, sequence-specific DNA binding, transcription factor activity, and two-component response regulator activity. Western blot results showed that enolase protein expression decreased obviously in decapeptide-treated cells of S. mutans. Conclusion The protein expression of S. mutans significantly changed after synthetic antimicrobial decapeptide treatment, suggesting that decapeptide may present a preferential effect on oral caries by changing the expression of certain key proteins, such as enolase protein.

Objective This paper aimed to determine the mRNA expression of osteoclast-related factors interleukin-6 (IL-6), interleukin-12 (IL-12) p35, IL-12p40, matrix metalloproteinase-9 (MMP-9), nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), receptor activator of nuclear factor-κB (RANK), and tumor necrosis factor-α (TNF-α) mRNA in murine macrophages infected by a periodontitis patient’s own tissue nucleic acid. Another aim was to investigate the effects of a periodontitis patient’s own tissue nucleic acid on the differentiation of macrophages into osteoclasts. Methods Inflammatory periodontal tissue samples of chronic periodontitis patients were taken during periodontal flap surgery, and healthy gingival tissue samples were taken from orthodontic patients during tooth extractions. Total RNA from periodontal tissue was extracted and reversely transcribed into cDNA and then cryo-preserved until further use. First, specific sequence oligodeoxynucleotide MT01 at a concentration of 1 μg•mL-1 was added in murine macrophage RAW264.7, and the cells were incubated for 3 hours. Cells with PBS (1 μg•mL-1) were used as negative controls. The inflammatory periodontal tissue cDNA and healthy periodontal tissue cDNA (1 μg•mL-1) was added subsequently. There were four experimental groups: healthy periodontal tissue cDNA+ RAW264.7, inflammatory periodontal tissue cDNA+RAW264.7, MT01+healthy periodontal tissue cDNA+RAW264.7, and MT01+inflammatory periodontal tissue cDNA+RAW264.7. Real-time quantitative polymerase chain reaction was used to detect the mRNA expression of osteoclast-related factors IL-6, IL-12p35, IL-12p40, MMP-9, NFATc1, RANK, and TNF-α mRNA after 3, 6, 12, and 24 hours. Results The mRNA levels of osteoclast-related factors NFATc1, MMP-9, TNF-α, IL-6, IL-12p40, IL-12p35, and RANK in RAW264.7 were markedly upregulated with the treatment of periodontitis patient’s own tissue nucleic acid. However, the mRNA expression of osteoclast-related factors was inhibited by use of an immunosuppressant MT01. Conclusion The periodontitis patient’s own tissue nucleic acid could promote the differentiation of murine macrophage into osteoclasts.

Objective This study aims to evaluate the quality of life (QOL) of patients who underwent resection of oral cancer and reconstruction by free anterolateral thigh perforator flaps (ALTF). Methods A total of 32 patients with oral and maxillofacial malignancies who had undergone the resection of oral cancer and reconstruction by ALTF were retrospectively analyzed. At 12 months postoperatively, the QOL of these patients was assessed by using the 14-item oral health impact profile (OHIP-14) and the medical outcome study short form-36 (SF-36) questionnaires. Results A total of 32 questionnaires were collected. In SF-36, the highest scoring domains were bodily pain (78.58±14.82), physical functioning (72.08±27.86), and the role of physical (60.00±42.63), whereas the lowest scoring domains were role-emotional (41.67±39.62), followed by mental health (50.75±13.07) and health transition (54.17±21.75). In OHIP-14, the lowest scoring domains were social disability (34.50±11.32) and handicap (36.04±12.05), indicating the functional recovery was better; and the highest scoring domains were physical pain (73.50±18.96) and psychological discomfort (60.17±20.66), indicating the functional recovery was worse. Conclusion The ALTF is an ideal selection for the reconstruction of oral defects after cancer resection. In using this flap, the basic social need of patients after surgery can be satisfied. Moreover, the appearance and the functions of chewing, deglutition, and speech can be restored in varying degrees. Thus, ALTF can improve the patients’ QOL.

Objective This study aims to investigate the color stability of ceromer with different thicknesses and different types of resin adhesive materials after accelerated aging and provide references for clinical application and selections. Methods Nine groups of experimental samples were used, and each group contained five samples. We made joint samples with ceromer having three different thicknesses (1.00, 0.75, 0.50 mm) combined with three different resin adhesive materials (RelyX Veneer, RelyX Unicem, Filtek Z350 Flow), respectively. All samples were placed into Xenon Lamp Aging Instrument to implement accelerated aging. Spectrophotometer was used to measure the lightness (L*), red green color value (a*), and blue yellow color value (b*) of all samples before and after accelerated aging. The change of lightness (ΔL), red green color value (Δa), blue yellow color value (Δb), and color variation (ΔE) were also calculated. We investigated the influence of ceromer veneer thicknesses and resin adhesive material types on color variation by two-factor analysis of variance. Results The thickness and type factors showed significant influence on ΔE values, and exhibited interactions (P<0.05). The ΔE values of all experimental groups were lower than 3.3. After the accelerated aging process, all L*, a*, and b* values of the experimental groups decreased and the ΔL values were lower than 2.0. Conclusion Ceromer veneer thickness and resin adhesive material types could affect the color stability of ceromer veneer and resin adhesive materials. The changes in lightness and color in ceromer veneer and resin adhesive materials are considered clinically acceptable after accelerated aging.

Objective This study aims to compare the fracture resistance of teeth restored with different post and core systems by cyclic loading test and to predict long-term effects. Methods A total of 15 recently extracted mandibular premolars without crowns were endodontically treated. The teeth were randomly divided into three groups with five teeth in each group. Group A, teeth restored with cast metal post and core. Group B, teeth with fiber post and resin core. Group C, teeth with resin filling. All of the teeth were restored with full-cast metal crowns. The specimens were exposed to 300 000 cyclic loadings in a cyclic loading machine and 1 000 thermal cycles between 5 and 55 ℃. All of the samples were loaded in AG-IS mechanical testing machine with a compressive load until fracture occurred. The fracture load and the fracture mode of each tooth were recorded. Results The fracture resistance in group B and C were higher than that of the cast metal post and core restoration (P<0.05). Repairable fractures were observed in group B and C, whereas unrestorable and catastrophic fractures were found in group A. Conclusion Fiber post and resin filling is a good choice to restore endodontically treated teeth.

With the development of medical radiography, cone beam computed tomography (CBCT) has been widely used in stomatology because of its numerous advantages, such as adequate spatial resolution, low radiation, undistorted threedimensional tissue information, and good applicability for hard tissue imaging. Traditional periapical radiography is based on two-dimensional image which displays the three-dimensional object and its surrounding structures. Periapical radiography can only show the overlapping mesio-distally direction bone destruction, can’t show buccolingual direction bone destruction. As a kind of three-dimensional imaging technology, CBCT can show three-dimensional structure of the organization from sagittal, coronal and axial direction, to overcome the defect of two-dimensional image such as overlap and deformation. CBCT has a unique advantage than periapical radiography in the diagnosis and treatment for periapical disease. This review will summarize the difference between CBCT and periapical radiography in the periapical disease.

Raman spectroscopy is an optical technology based on the theory of Raman scattering, which is generally used in the research of medical and biological science. Raman spectroscopy can be used to detect the molecular structures and components of proteins, lipids, DNA, and other biological molecules, and provide substantial information about molecules. Thus, Raman spectroscopy is generally considered a “molecular fingerprint”, and it has exceptional advantages in medical research. Moreover, this technique can reflect the changes in molecular structures and detect the alterations of chemical constituents in the samples. Raman spectroscopy, given its high sensitivity and specificity in the detection of the biological samples, has been successfully used to detect and diagnose diseases in numerous sites, such as skin, oral mucosa, breast, head, and neck. In this paper, we introduce the application of Raman spectroscopy in stomatology by conducting a review of the literature.

Pemphigus is a severe chronic autoimmune mucocutaneous bullous disease. Glucocorticoids are considered as the first line of treatment for this disease. Dysfunctional uterine bleeding is also observed as a result of hypothalamic-pituitaryovary axis dysfunction. This study reported one female patient with pemphigus vulgaris complicated with dysfunctional uterine bleeding upon systemic glucocorticoid usage. Before this disease was diagnosed, the patient experienced normal menstruation. The mechanism of dysfunctional uterine bleeding triggered by glucocorticoids is elucidated on the basis of case studies and literature review.