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Background/purpose: The unpredictable condition of cracked teeth warrants further investigation and clinical experiences. The purpose of this study was to collect and record data on demographics, clinical characteristics, different treatment modalities and survival of cracked teeth at 6-month, 1-year and 2-year recalls. Methods: 77 cracked teeth from 65 patients were included. Data on demographics, clinical parameters, treatment modalities and recall were collected. Binomial, multinomial and chi square tests were used for statistical analysis. Results: Most cracked teeth occurred in patients greater than 40 years old (p

BACKGROUND/PURPOSE: The objective structured clinical examination (OSCE) is a test designed to test technical, clinical, and practical competency in medicine teaching. This study tried to evaluate the influencing factors of the computer-based tests (CBT) results for dental students. MATERIALS AND METHODS: The 32 5th-year dental students of the dental school of National Taiwan University (NTU) joined preclinical CBT. The contents of CBT included clinical knowledge and practical skills of nine dental specialties. Twenty single-choice questions were played with the PowerPoint 2016 on a desktop, and the playing time for each question was 30 s. Several factors including the gender, age, and dental student admission ways (with or without the skill tests) were evaluated. Also, the comparison between the clerk's grade and CBT scores of nine dental specialties was performed. The students also filled the feedback questionnaire about the examination questions and suggestions for the CBT. RESULTS: There were no significant differences in the mean CBT scores between male and female dental students, between two groups of dental students with or without the skill tests in the admission process, and among three different age groups of dental students. The clerk's scores were not directly related to the CBT scores. CONCLUSION: The CBT has been well-intentioned in dental education since 2022 in Taiwan. The CBT results revealed that the conjunction of knowledge from the textbook and clinical observation should be enhanced. The guideline should be established to integrate CBT into preclinical education and promote the performance of clinical work of dental students.

The signaling mechanisms for Porphyromonas gingivalis lipopolysaccharide (PgLPS)-induced inflammation in human dental pulp cells are not fully clarified. This in vitro study aimed to evaluate the involvement of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway in PgLPS-induced pulpal inflammation.Human dental pulp cells (HDPCs) were challenged with PgLPS with or without pretreatment and coincubation with a PI3K/Akt inhibitor (LY294002). The gene or protein levels of PI3K, Akt, interleukin (IL)-6, IL-8, alkaline phosphatase (ALP), osteocalcin and osteonectin were analyzed by reverse transcription polymerase chain reaction (PCR), real-time PCR, western blotting, and immunofluorescent staining. In addition, an enzyme-linked immunosorbent assay was used to analyze IL-6 and IL-8 levels in culture medium.In response to 5 μg/ml PgLPS, IL-6, IL-8, and PI3K, but not Akt mRNA expression of HDPCs, was upregulated. IL-6, IL-8, PI3K, and p-Akt protein levels were stimulated by 10-50 μg/ml of PgLPS in HDPCs. PgLPS also induced IL-6 and IL-8 secretion at concentrations higher than 5 μg/ml. Pretreatment and co-incubation by LY294002 attenuated PgLPS-induced IL-6 and IL-8 mRNA expression in HDPCs. The mRNA expression of ALP, but not osteocalcin and osteonectin, was inhibited by higher concentrations of PgLPS in HDPCs.P. gingivalis contributes to pulpal inflammation in HDPCs by dysregulating PI3K/Akt signaling pathway to stimulate IL-6 and IL-8 mRNA/protein expression and secretion. These results are useful for understanding the pulpal inflammation and possible biomarkers of inflamed pulp diagnosis and treatment.

Transforming growth factor-β1 (TGF-β1) regulates wound healing/regeneration and aging processes. Dental pulp stem cells from human exfoliated deciduous teeth (SHED) are cell sources for treatment of age-related disorders. We studied the effect of TGF-β1 on SHED and related signaling. SHED were treated with TGF-β1 with/without pretreatment/co-incubation by SB431542, U0126, 5Z-7-oxozeaenol or SB203580. Sircol collagen assay, 3-(4,5-Dimethylthiazol-2-yl)-2,5- diphenyl tetrazolium bromide (MTT) assay, alkaline phosphatase (ALP) assay, RT-PCR, western blotting and PathScan phospho-ELISA were used to measure the effects. We found that SHED expressed ALK1, ALK3, ALK5, TGF-RII, betaglycan and endoglin mRNA. TGF-β1 stimulated p-Smad2, p-TAK1, p-ERK, p-p38 and cyclooxygenase-2 (COX-2) protein expression. It enhanced proliferation and collagen content of SHED that were attenuated by SB431542, 5Z-7-oxozeaenol and SB203580, but not U0126. TGF-β1 (0.5-1 ng/ml) stimulated ALP of SHED, whereas 5-10 ng/ml TGF-β1 suppressed ALP. SB431542 reversed the effects of TGF-β1. However, 5Z-7-oxozeaenol, SB203580 and U0126 only reversed the stimulatory effect of TGF-β1 on ALP. Four inhibitors attenuated TGF-β1-induced COX-2 expression. TGF-β1-stimulated TIMP-1 and N-cadherin was inhibited by SB431542 and 5Z-7-oxozeaenol. These results indicate that TGF-β1 affects SHED by differential regulation of ALK5/Smad2/3, TAK1, p38 and MEK/ERK. TGF-β1 and SHED could potentially be used for tissue engineering/regeneration and treatment of age-related diseases.

Objectives: The rs12611091 variant in the BR serine/threonine kinase 1 gene is one of the variants previously associated with age at natural menopause. So far, this variant has not been replicated in Taiwanese women. The purpose of this study was to determine the association between rs12611091 and age at natural menopause based on physical activity. Methods: A total of 1,758 women were eligible for analysis whose information about menopause was collected from the Taiwan Biobank. Multiple linear regression analysis was used for analysis. Results: The mean age (standard deviation) at natural menopause was 50.82 (3.59) years. Of the eligible participants, 56.94% were rs12611091 CC carriers, 36.69% were TC carriers, and 6.37% were TT carriers. Compared to CC carriers, TC and TT carriers were associated with early menopause (β = −0.42, P = 0.02 and −0.87, P = 0.01, respectively). There was a significant interaction between rs12611091 and physical activity (P for interaction = 0.02). Compared to rs12611091 CC carriers, TC and TT carriers who were physically inactive were significantly associated with earlier menopause (β = −0.88, P

Objective In Taiwan, the overall incidence of acute respiratory distress syndrome (ARDS) is 15.74 per 100,000 person-years, the mortality rate is 57.8%, and its overall prevalence in the intensive care unit (ICU) is 10.4%. Women who are pregnant and have ARDS have a high risk of fetal death and fetal asphyxia. Case report A 26-1/7-week pregnant woman presented with upper respiratory infection symptoms progressing to ARDS. While receiving ventilation, maintaining a prone position is an option for pregnant patients with severe ARDS. This case demonstrated a supplementary approach for pregnant women with ARDS. Conclusion Prone position ventilation is indicated for pregnant women, as for any patient with ARDS. The Proning Severe ARDS Patients trial showed no difference in the complication between pregnant patients and other groups.

AIM To investigate the effects of butyric acid (BA), a metabolic product generated by pulp and root canal pathogens, on the viability and intercellular adhesion molecule-1 (ICAM-1) production of endothelial cells, which are crucial to angiogenesis and pulpal/periapical wound healing. METHODOLOGY Endothelial cells were exposed to butyrate with/without inhibitors. Cell viability, apoptosis and reactive oxygen species (ROS) were evaluated using an MTT assay, PI/annexin V and DCF fluorescence flow cytometry respectively. RNA and protein expression was determined using a polymerase chain reaction assay and Western blotting or immunofluorescent staining. Soluble ICAM-1 (sICAM-1) was measured using an enzyme-linked immunosorbent assay. The quantitative results were expressed as mean ± standard error (SE) of the mean. The data were analysed using a paired Student's t-test where necessary. A p-value ≤0.05 was considered to indicate a statistically significant difference between groups. RESULTS Butyrate (>4 mM) inhibited cell viability and induced cellular apoptosis and necrosis. It inhibited cyclin B1 but stimulated p21 and p27 expression. Butyrate stimulated ROS production and hemeoxygenase-1 (HO-1) expression as well as activated the Ac-H3, p-ATM, p-ATR, p-Chk1, p-Chk2, p-p38 and p-Akt expression of endothelial cells. Butyrate stimulated ICAM-1 mRNA/protein expression and significant sICAM-1 production (p

The rat has been considered as an appropriate animal model for the study of the mineralization process in humans. In this work, we found that the phosphorus species in human dentin characterized by solid-state NMR spectroscopy consist mainly of orthophosphate and hydrogen phosphate. Some orthophosphates are found in a disordered phase, where the phosphate ions are hydrogen-bonded to structural water, some present a stoichiometric apatite structure, and some a hydroxyl-depleted apatite structure. The results of this study are largely the same as those previously obtained for rat dentin. However, the relative amounts of the various phosphorus species in human and rat dentin are dramatically different. In particular, stoichiometric apatite is more abundant in human dentin than in rat dentin, whereas the converse is true for disordered-phase orthophosphates. Furthermore, spatial proximity among all phosphorus species in human dentin is identical within experimental error, in contrast to what observed for rat dentin. Although it is not clear how these spectroscopic data could relate to the hierarchical structure or the mechanical properties of teeth, our data reveal that the molecular structures of human and rat dentin at different growth stages are not exactly the same.

A highly efficient and chemoselective one-pot protocol for the diversity-oriented synthesis of two types of coumarin-based formal cross-coupling adducts, furo[3,2-c]coumarins and 3-benzofuranyl chromenones, is described. Key attributes of the methodology are an initial chemoselective acylation of functionalized phosphorus zwitterions and a subsequent chemoselective intramolecular Wittig reaction that preferentially resulted in one of the two coumarin derivatives in high yield, depending on relative reactivities and the addition sequence of the acylating agents.

Introduction The purpose of this study was to investigate the distribution, predisposing factors, and clinical characteristics of invasive cervical resorption (ICR). Methods Cases with ICR from 2009–2019 were collected. Clinical records and radiographs were reviewed. Descriptive analysis was performed in combination with univariate analysis and the Fisher exact test. Results A total of 63 ICR teeth from 31 patients (14 men and 17 women) were found. The patients’ ages ranged from 18–81 years, with a mean age of 45.77 years. Most patients had a single ICR lesion. Among the 63 ICR teeth, maxillary anterior teeth (47.62%) were the most commonly affected followed by maxillary premolars (20.63%). Maxillary teeth (76.19%) were more prone to ICR than mandibular teeth (23.81%). Most patients denied all major systemic diseases. The most common dental-related factors were dental/orofacial trauma (33.33%), periodontal treatment (26.98%), restoration/crown (17.46%), and orthodontic treatment (15.87%). Most teeth showed no percussion/palpation pain, probing depth >3 mm, abscess formation, sinus tracts, or periapical lesions. The pulp status was mainly vital (73.02%). The presence of percussion pain and probing depth differed significantly among Heithersay ICR classification groups. Conclusions ICR showed no difference in sex or age. Maxillary anterior teeth were the most affected in a Taiwanese population. Traumatic injury, periodontal treatment, and orthodontic treatment were the significant predisposing factors. Furthermore, affected teeth typically lacked clinical signs and symptoms. Radiographic examination is critical for early diagnosis. In advanced cases, deep pockets and abscess formation were seen. These results are helpful for the diagnosis of ICR and further effective treatment.

The 4-dimethylaminobenzoic acid ethyl ester (DMABEE) is an important co-initiator for resin polymerization in dental resinous materials. As a radical forming chemical with high lipophilicity, the genotoxicity and cytotoxicity of DMABEE deserve prudent investigation. In this study, we found that DMABEE reduced the viability and proliferation of Chinese hamster ovary (CHO-K1) cells in a dose-dependent manner, and altered cell morphology at higher concentrations. G0/G1 cell cycle arrest was induced by DMABEE at 0.25-0.75 mM, and cell proportion of sub-G0/G1 phase was significantly elevated at 1 mM while cell apoptosis was observed. Genotoxic effect was noted when cells were treated by 0.1 mM DMABEE, as revealed by increase of micronucleus formation. Reactive oxygen species overproduction was observed as cells treated with 0.75 and 1 mM, while elevation of intracellular glutathione was noticeable since 0.1 mM. Contrary to our expectation, pretreatment by N-acetyl-l-cysteine enhanced the toxicity of DMABEE on CHO-K1 cells. Catalase mildly reduced the toxic effect and carboxylesterase showed obvious ability to reverse the toxicity of DMABEE. These findings highlight the mechanism of DMABEE toxicity and provide clues for safety improvement of its application in clinical dental treatment.

Background Taiwan has a high national caesarean rate coupled with a low vaginal birth after caesarean (VBAC) rate. Studies suggest that women do not receive sufficient information about birth choices after caesarean in Taiwan and shared decision making (SDM) is not an expectation. This pilot study aimed to test the feasibility of using a birth choices decision aid to improve women's opportunity for engagement in SDM about birth after cesarean. Methods A two-phase sequential mixed methods pilot study was conducted in a regional hospital in northern Taiwan. Phase I involved a randomized pre-test and post-test experimental design. Participants with one previous caesarean section (CS) were recruited at 14-24 weeks. A total of 65 women completed a baseline survey and were randomly allocated to either the intervention (birth choice decision aid booklet) or usual care (general maternal health booklet) group. A follow up survey at 37-38 weeks measured change in decisional conflict, knowledge, and birth mode preference. Birth outcomes and satisfaction were assessed one month after birth. Phase II consisted of postnatal interviews with women at one month after birth, to explore women's decision making experiences, using a constant comparative analytic technique and thematic analysis. Results Decisional conflict was relatively low at baseline for all women. Although there were reductions in decisional conflict at follow up, differences between groups were not statistically significant. Women's early preferences regarding mode of birth influenced their knowledge-seeking behaviors and expectations or intention for engaging in SDM during pregnancy. Improvements in knowledge for the decision aid group were larger than for the usual care group, although differences between groups were not statistically significant. Four themes related to key factors in decision making were clarity, safety and risk, consistency, and support. Conclusion A cultural shift is needed to align expectations and relationships towards SDM for birth in Taiwan. Simulation-based strategies and tailored communication skills should be explored to enhance skills in decision coaching for providers. Use of interactive multimedia technology may provide opportunities to increase engagement with tools and support women during decision consultations. Midwife-led continuity of care models may also be beneficial in empowering women to actively share decisions and achieve the birth that is best for them.

Aim To describe the clinical characteristics and radiographic findings of horizontal root fractures (HRF) in posterior teeth without a history of dental trauma. Methodology A total 24 patients and 31 HRF cases in 28 posterior teeth were collected from 2006 to 2015. Clinical examinations and radiographic imaging were evaluated. Value of confidence intervals of the proportions were calculated for data presentation. Results The number of males (54%) was similar to females (46%). The patients were predominantly between 50 to 70 years of age (75%). Most HRF cases were found in non-endodontically-treated teeth (79%,), without crown and bridge restorations (82%), and maxillary molars (54%). Many roots of maxillary molars had developed HRF, and the probability was nearly equal. Fractured teeth usually presented with periodontal and apical bone loss, and most patients (92%) were diagnosed with full mouth chronic periodontitis. Tooth wear was another common clinical feature among these patients. Conclusions HRF in posterior teeth without dental trauma occurred mainly in patients’ age between 50 to 70 years old, in non-endodontically-treated teeth, teeth with attrition but without crown and bridge restorations, maxillary molars, and with periodontal and periapical bony destruction. Periodontal condition, occlusal wear, and patients’ age at diagnosis were the possible related factors. HRF in posterior teeth without dental trauma is a diagnostic challenge and even misdiagnosed. A thorough clinical examination, radiographic analysis, and recognition of the clinical characteristics are helpful in the early diagnosis and treatment of HRF. This article is protected by copyright. All rights reserved.

An enantioselective synthesis of benzopyrano[3,4-c]pyrrolidine derivatives via organocatalyzed [3 + 2] cycloaddition has been achieved. Cinchona alkaloid-derived organocatalysts as Brønsted bases have been examined for this asymmetric cycloaddition of o-hydroxy aromatic aldimines with 3-substituted coumarins. An unexpected rearrangement of the quaternary acyl moiety in the products resulted in an in situ protection of the o-hydroxy group.

This study investigated the effect of massive spalling of intermetallic compounds (IMCs) on the microstructural evolution and mechanical properties of solder joints after multiple reflows. SAC305 solder was reflowed on substrates with four Co-based surface finishes: electroless Co (EC), electroless Co/immersion Au (ECIG), electroless Co/electroless Pd (ECEP), and electroless Co/electroless Pd/immersion Au (ECEPIG). CoSn 3 was the main intermetallic compound (IMC) that formed in the systems, and it massively spalled in the systems with Pd and high P content. Systems with massive spalling have a high shear strength and low shear height owing to solid solution strengthening. Due to strain hardening, high shear velocity caused high strength in all systems. Massive spalling of CoSn 3 transformed the failure mode from brittle to ductile and enhanced the shear strength of the joints.

Background/Purpose: Apical surgery is an option for management of endodontically-treated tooth with persistent periapical lesions or symptom and sign. The objective of this study was to investigate the correlation between the demography, preoperative, postoperative factors and healed rate of apical surgery. Methods: Subjects were retrospectively collected from patients who received apical surgery/apicoectomy at the Endodontic Department, National Taiwan University Hospital from January 2013 to June 2015. The standard apical surgery procedures were performed. The demography, preoperative clinical and radiographic examination data as well as postoperative variables were collected. The outcome assessment was carried out after surgery. Statistical analysis was performed by chi square test to evaluate the potential outcome predictors. Results: Total 187 patients and 234 teeth receiving apical surgery were included. 53 male and 134 female patients were collected. The age was ranged between 17 and 89 years old and the mean age was 43.64 years old. Better healed rate with significant differences were observed in female patient (p 2 mm short of apex (p

An efficient synthesis of multifunctional alkenes starting from substituted acrylates and aldehydes has been developed via phosphine-catalyzed Wittig reactions. The reactions proceed smoothly even under mild conditions (30–60 °C) via a phosphine/phosphine oxide catalytic cycle using phenyl silane as the reducing agent. According to this simple protocol, the desired products are obtained in moderate to excellent yields as single stereoisomers.

Introduction A cemental tear is a special type of surface root fracture noted in combination with periodontal and/or periapical bony destruction. We hypothesized that clinical characteristics and treatment techniques may affect the prognosis of teeth with cemental tears. Methods Treatment outcome for the teeth with a cemental tear was assessed in a multicenter cemental tear study project. Of the 71 teeth with cemental tears, 38 teeth (53.5%) were extracted. The remaining 33 teeth (46.5%) were examined for a treatment outcome of healed, questionable, or failed. Results Outcome assessment found that 51.5% (17/33), 42.4% (14/33), and 6.1% (2/33) of teeth were classified as healed, questionable, and failed, respectively. Additive bivariate analysis indicated a significant difference between treatment outcome and the length ( P = .01) and apicocoronal location ( P = .02) of the separated root fragments. Logistic regression analysis found that treatment technique and apicocoronal location of cemental tears may affect the treatment outcome. The percentage of healed cemental tear cases located in the apical, middle, and cervical third of roots was 11.1%, 66.7%, and 60.0%, respectively. By surgical management, 57.7% of cemental tears were healed, whereas only 28.6% cases were healed after nonsurgical treatment. Conclusions Most teeth with cemental tears can be retained to function by nonsurgical and surgical periodontal and endodontic treatment. Clinical diagnosis and treatment of cemental tears should also consider the apicocoronal location and the type of treatment technique to improve outcomes.

A Bu3P-mediated mild and efficient synthesis of multi-functional alkenes has been described starting from substituted acrylate with aldehydes. In situ generated zwitterionic intermediates underwent proton-exchange to afford ylide intermediates, which were trapped by corresponding aldehydes providing the products in up to 92% yield with complete E-stereoselectivity. Further derivatization of the products was performed to furnish functional pyridazinones.

Background/purpose Various toxic products are generated by periodontal pathogens. Porphyromonas gingivalis has been found to generate lipopolysaccharide (LPS) that may potentially affect periodontal health. However, the precise effects of P. gingivalis LPS on human gingival fibroblasts (GFs) await further investigation. Materials and methods Human GFs were cultured and exposed to different concentrations of P. gingivalis LPS (0.1–10 μg/mL) for 24 hours. Cytotoxicity was analyzed by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Total ribonucleic acid (RNA) was isolated and subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) using specific primer sets. Culture medium was collected for determination of prostaglandin E 2 (PGE 2 ), PGF 2α , and interleukin-8 (IL-8) production by enzyme-linked immunosorbent assay. ERK1/2 phosphorylation in GFs was evaluated by Western blotting. In some experiments, U0126 (a MEK/ERK inhibitor) was added to the GFs culture 30 minutes before LPS and culture medium was also collected for analysis. Results P. gingivalis LPS (0.1–10 μg/mL) showed little cytotoxicity and morphologic changes of GFs. P. gingivalis LPS obviously stimulated the cyclooxygenase-2 (COX-2) and IL-8 messenger RNA expression of GFs after 24 hours of exposure. Moreover, P. gingivalis LPS induced PGE 2 , PGF 2α , and IL-8 production in GFs. P. gingivalis LPS also induced ERK1/2 phosphorylation in GFs. Stimulation of PGE 2 production by P. gingivalis LPS was completely attenuated by U0126, whereas U0126 only partially inhibited the LPS-induced IL-8 production in the same condition. Conclusion Our data indicate that P. gingivalis LPS stimulates gene expression of differential inflammatory mediators (COX-2 and IL-8) as well as prostanoids and IL-8 production in GFs. These events are associated with MEK/ERK signaling and crucial in the pathogenesis of inflammatory periodontal diseases.

A convenient protocol for the preparation of tricyclic fused furans in one step starting from acid chlorides and Michael acceptors is described. The reaction conditions are mild, operationally simple, and have a broad substrate scope. The reaction is believed to proceed by an intramolecular Wittig reaction with a phosphorus ylide as the key intermediate.

Aims Butyric acid is one major metabolic product generated by anaerobic Gram-negative bacteria of periodontal and root canal infection. Butyric acid affects the activity of periodontal cells such as osteoblasts. The purposes of this study were to investigate the effects of butyrate on MG-63 osteoblasts. Methods MG-63 cells were exposed to butyrate and cell viability was estimated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The mRNA and protein expression of type I collagen and cell cycle-related proteins were measured by reverse-transcriptase polymerase chain reaction (RT-PCR), western blotting or immunofluorescent staining. Cellular production of reactive oxygen species (ROS) was analyzed by 2',7'-dichlorofluorescein (DCF) fluorescence flow cytometry. Results Exposure to butyrate suppressed cell proliferation, and induced G2/M (8 and 16 mM) cell cycle arrest of MG-63 cells. Some cell apoptosis was noted. The mRNA expression of cdc2 and cyclin-B1 decreased after exposure to butyrate. The protein expression of type I collagen, cdc2 and cyclin B1 were decreased, whereas the expression of p21, p27 and p57 was stimulated. Under the treatment of butyrate, ROS production in MG-63 cells markedly increased. Conclusions The secretion of butyric acid by periodontal and root canal microorganisms may inhibit bone cell growth and matrix turnover. This is possibly due to induction of cell cycle arrest and ROS generation and inhibition of collagen expression. These results suggest the involvement of butyric acid in the pathogenesis of periodontal and periapical tissue destruction by impairing bone healing responses.

A vertical root fracture (VRF) is a root fracture extending along the longitudinal axis of roots and is often noted in endodontically treated teeth. However, the clinical and radiographic characteristics of VRFs are not completely known.A total of 65 teeth with 68 vertical fractured roots in 58 Chinese patients were investigated. The clinical examination records and radiographic images were reviewed in detail.A total of 24 male (41.38%) and 34 female (58.62%) patients aged 25-90 years (average = 57 years) were included; 51 (87.93%) and 7 (12.07%) patients exhibited 1 tooth and 2 teeth with VRFs, respectively, in the dentition. VRFs occurred mainly in the mesial root (20 roots, 57.14%) of the mandibular molars (29 teeth, 44.62%). Clinically, teeth with VRFs usually presented a periodontal probing depth5 mm (44 teeth, 91.67%, P .001) with a prosthesis (55 teeth, 84.62%, P .001) and a relatively intact dentition (42 patients exhibited4 missing teeth in the dentition, 77.78%, P .001). Most of the nonendodontically treated VRFs exhibited attrited occlusal surfaces. Radiographic characteristics of the teeth with VRFs were typically associated with prior root canal treatment (56 teeth, 86.15%, P .001), periodontal bone loss (62 teeth, 95.38%, P .001), apical bone loss (52 teeth, 80.00%, P .001), and periodontal ligament widening (61 teeth, 93.85%, P .001). The mesial roots of the mandibular molars were most susceptible to VRFs in both endodontically and nonendodontically treated teeth.These results elucidated some clinical and radiographic and diagnostic features that facilitate VRF identification.

Transforming growth factor-β1 (TGF-β1) plays an important role in the pulpal repair and dentinogenesis. Plasminogen activation (PA) system regulates extracellular matrix turnover. In this study, we investigated the effects of TGF-β1 on PA system of dental pulp cells and its signalling pathways. Dental pulp cells were treated with different concentrations of TGF-β1. MTT assay, reverse transcription-polymerase chain reaction, Western blotting and enzyme-linked immunosorbant assay (ELISA) were used to detect the effect of TGF-β1 on cell viability, mRNA and protein expression of urokinase-type plasminogen activator (uPA), uPA receptor (uPAR), plasminogen activator inhibitor-1 (PAI-1) as well as their secretion. The phosphorylation of Smad2 and TAK1 was analysed by Pathscan ELISA or Western blotting. Cells were pretreated with SB431542 (ALK5/Smad2/3 inhibitor), 5z-7-oxozeaenol (TAK1 inhibitor) and U0126 (MEK/ERK inhibitor) for examining the related signalling. TGF-β1 slightly inhibited cell growth that was reversed by SB431542. TGF-β1 upregulated both RNA and protein expression of PAI-1 and uPAR, whereas it downregulated uPA expression. Accordingly, TGF-β1 stimulated PAI-1 and soluble uPAR (suPAR) secretion of pulp cells, whereas uPA secretion was inhibited. TGF-β1 induced the phosphorylation of Smad2 and TAK1. In addition, SB431542, 5z-7-oxozeaenol and U0126 attenuated the TGF-β1-induced secretion of PAI-1 and suPAR. These results indicate that TGF-β1 is possibly involved in the repair/regeneration and inflammatory processes of dental pulp via regulation of PAI-1, uPA and uPAR. These effects of TGF-β1 are related to activation of ALK5/Smad2, TAK1 and MEK/ERK signalling pathways. Clarifying the signal transduction for the effects of TGF-β1 is helpful for pulpo-dentin regeneration and tissue engineering. Copyright © 2016 John Wiley & Sons, Ltd.

Introduction Clinical research regarding the clinical and histopathologic characteristics of cemental tear is limited in the endodontic literature. The objective of this study was to evaluate the morphology, apicocoronal location, and the histologic characteristics of cemental tear. Methods The material was collected during 1987–2009 and consisted of 54 teeth that were presented with cemental tears by histologic examination. To investigate the atypical prospects among the groups of each variable, a series of the Poisson χ 2 goodness-of-fit tests were conducted to test for a fit of a discrete, uniform distribution. Results Cemental tear occurred mainly in incisors (74.1%), proximal root surfaces (79.6%), male patients (74.1%), and patients older than 60 years (72.3%). They were noted often in the middle third of root (45.3%), but 41.5% of cemental tears were noted over the apical region. The morphology of cemental tear was either small/thin piece-shaped (77.4% cases) involving 1 root surface or U-shaped (22.6%) involving >1 root surface. The size of cemental tear had an average length of 3.8 mm, width of 2.2 mm, and thickness of 0.9 mm. The separations of cemental tears occurred at cementodentinal junction (77.6%) relative to cementum (22.4%). The adhered soft tissue was either granulation tissue (92.3%) or cyst (7.7%). Conclusions Cemental tear mainly occurs in incisors of male and older persons. It is also popularly noted in the apical region mimicking an endodontic lesion and some with cystic change. Clinically, endodontists should know this disease entity, make accurate early diagnosis, and totally remove the cemental tear during apical surgery to improve the prognosis.

Background and Objective: Short-chain fatty acids, such as butyric acid and propionic acid, are metabolic by-products generated by periodontal microflora such as Porphyromonas gingivalis, and contribute to the pathogenesis of periodontitis. However, the effects of butyrate on the biological activities of gingival fibroblasts (GFs) are not well elucidated. Material and Methods: Human GFs were exposed to various concentrations of butyrate (0.5–16 mm) for 24 h. Viable cells that excluded trypan blue were counted. Cell cycle distribution of GFs was analyzed by propidium iodide-staining flow cytometry. Cellular reactive oxygen species (ROS) production was measured by flow cytometry using 2’,7’-dichlorofluorescein (DCF). Total RNA and protein lysates were isolated and subjected to RT-PCR using specific primers or to western blotting using specific antibodies, respectively. Results: Butyrate inhibited the growth of GFs, as indicated by a decrease in the number of viable cells. This event was associated with an induction of G0/G1 and G2/M cell cycle arrest by butyrate (4–16 mm) in GFs. However, no marked apoptosis of GFs was noted in this experimental condition. Butyrate (> 2 mm) inhibited the expression of cdc2, cdc25C and cyclinB1 mRNAs and reduced the levels of Cdc2, Cdc25C and cyclinB1 proteins in GFs, as determined using RT-PCR and western blotting, respectively. This toxic effect of butyrate was associated with the production of ROS. Conclusion: These results suggest that butyrate generated by periodontal pathogens may be involved in the pathogenesis of periodontal diseases via the induction of ROS production and the impairment of cell growth, cell cycle progression and expression of cell cycle-related genes in GFs. These events are important in the initiation and prolongation of inflammatory processes in periodontal diseases.

Introduction Cemental tears often show characteristics mimicking a periapical or periodontal lesion. This leads to difficulty in the early diagnosis of cemental tears. Methods In this multicenter study, 71 teeth with cemental tears being confirmed by direct inspection or histological examination were included. For each case, demographic data, dental history, clinical and radiographic findings, and the results of exploratory surgery were recorded and analyzed. Results Maxillary or mandibular incisors (76.1%) were most frequently affected by cemental tears. Univariate analysis of predisposing factors found that teeth with cemental tears occurred more commonly in men (77.5%) and patients older than 60 years of age (73.2%). Analysis of clinical characteristics showed that teeth with cemental tears were prone to have abscess formation (66.2%), a deep pocket >6 mm (73.2%), positive vitality test (65.3%), healthy antagonist teeth (84.3%), and moderate to severe attrition (77.9%). About 56.3% of cemental tears could be detected on preoperative radiographs. Further analysis of radiographic findings showed that teeth with cemental tears were more likely to have periodontal bone destruction (85.9%) or periapical bone destruction (64.8%). Conclusions Endodontists and dentists may avoid misdiagnosis and unnecessary treatment of teeth with cemental tears if they can properly evaluate the radiographs and pulp vitality of teeth as well as know the predisposing factors and clinical characteristics of teeth with cemental tears in advance.

The purpose of this study was to evaluate influence of etching ability of one-step self-etch adhesives on bonding to non-carious cervical sclerotic lesion. Forty-eight human maxillary premolars with and without natural non-carious cervical sclerotic lesions at buccal surfaces were used in this study. Artificial wedge-shaped lesions were prepared in sound premolars. All lesions were bonded with Bond Force (BF; pH=2.3) or G-Bond Plus (GBA; pH=1.5) according to the manufacturers' instructions. After water storage for 24 hours at 37°C, bonded specimens were subjected to microtensile bond test to measure bond strength to the gingival wall in each lesion. The μTBS of BF to the natural lesion was significantly lower than that of artificial lesion (p0.05), while for GBA, there is no significant difference (p0.05). There was no difference in μTBS to artificial lesion between these two adhesives, however in case of non-carious cervical sclerotic lesion, the μTBS of GBA was statistically higher than that of BF.

Geopolymers are a new class of materials formed by the condensation of aluminosilicates and silicates obtained from natural minerals or industrial wastes. In this work, the sol-gel method is used to synthesize precursor materials for the preparation of geopolymers. The geopolymer samples prepared by our synthetic route have been characterized by a series of physical techniques, including Fourier-transform infrared, X-ray diffraction, and multinuclear solid-state NMR. The results are very similar to those obtained for the geopolymers prepared from natural kaolinite. We believe that our synthetic approach can offer a good opportunity for the medical applications of geopolymer. (c) 2010 Elsevier Inc. All rights reserved.

Chang MC, Chen YJ, Lee MY, Lin LD, Wang TM, Chan CP, Tsai YL, Wang CY, Lin BR, Jeng JH. Prostaglandin F2α stimulates MEK-ERK signalling but decreases the expression of alkaline phosphatase in dental pulp cells. International Endodontic Journal, 43, 461–468, 2010. Abstract Aim To study prostaglandin F2α (PGF2α) receptor expression and downstream signalling in cultured human dental pulp cells and the effect of PGF2α on the alkaline phosphatase (ALP) activity of dental pulp cells. Methodology Human dental pulp cells were cultured and exposed to PGF2α. The expression of PGF2α (FP) receptors was analysed by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting. The activation of extracellular regulated kinase (ERK) and cAMP responsive element binding protein/activating transcription factor-1 (CREB/ATF-1) signalling was determined by Western blotting. The expression of ALP in pulp cells after exposure to PGF2α was evaluated by ALP staining and PCR. Results Dental pulp cells expressed FP receptor mRNA and protein. Exposure to PGF2α revealed little cytotoxicity to pulp cells. PGF2α induced both ERK and CREB/ATF-1 phosphorylation in pulp cells. Exposure to PGF2α (>1 μmol L−1) further decreased the ALP activity and mRNA expression. However, U0126 (an inhibitor of MEK1) showed little preventive effect on the decline of ALP activity in dental pulp cells by PGF2α. Conclusion PGF2α may potentially activate FP receptors leading to ERK/CREB-ATF-1 activation during its production in inflamed dental pulp. PGF2α attenuated the ALP activity of pulp cells possibly via pathways not solely by MEK/ERK activation. PGF2α is a contributing factor of pulpal inflammation by regulating the activities of pulp cells.