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Substantial evidence has indicated that Notch and bone morphogenetic protein (BMP) signaling may regulate odontoblastic differentiation. Hairy/enhancer‑of‑split related with YRPW motif 1 (Hey1), a downstream target gene of Notch and BMP signaling, is expressed in dental pulp tissues and has been demonstrated to be responsible for osteoblast mineralization. The aim of this study was to investigate the effects of Hey1 on odontoblast differentiation. The results of the study demonstrated that Hey1 expression in odontoblast‑lineage cells (OLCs) was upregulated by stimulation of osteoblastic/odontoblastic differentiation medium containing ascorbic acid, β‑glycerol phosphate and dexamethasone. Furthermore, stable Hey1‑overexpressing cells expressed higher levels of dentin sialophosphoprotein (DSPP) and exhibited higher mineralization capabilities following stimulation by differentiation medium. Furthermore, RNA interference‑mediated knockdown of Hey1 downregulated the expression levels of DSPP in OLCs stimulated by differentiation medium. Taken together, the findings indicate that Hey1 may be a positive regulator of odontoblastic differentiation. The present study broadens the understanding of odontoblast differentiation and biomineralization.

Vertical root fractures (VRFs) in teeth without endodontic treatment are relatively uncommon. The diagnosis is based on clinical and radiographic presentations. It might be difficult to detect VRFs in non-endodontically treated molars by conventional radiographs in certain situations because of the limitations of 2D images and many others factors such as the VRFs being in their early stages. Root morphology variation and the orientation of VRFs can influence conventional radiographic detection and the interpretation of a radiolucent fracture line. The four case reports presented here describe and discuss the use of cone-beam computed tomography (CBCT) in successfully diagnosing VRFs based on direct visualization of radiolucent lines, especially those suspected from routine conventional radiographs, as well as their symptoms and clinical findings. CBCT also provides more information on the presence of VRFs.

Diagnosis of root fractures is generally based on clinical and radiographic presentations. This case report aims to detect horizontal/oblique root fractures in posterior teeth using a combination of conventional radiographs and cone-beam computed tomography (CBCT). Three maxillary first molars with horizontal/oblique root fractures in the palatal roots are presented. More detailed information on root fractures can be obtained using CBCT compared with conventional radiography. As such, CBCT might be a useful complementary diagnostic method to conventional radiography in cases of suspected horizontal/oblique root fractures.

This case series describes observations of 12 patients who developed horizontal root fractures in non-endodontically treated teeth. Using clinical and radiographic examination, horizontal fractures were observed in eight maxillary first molars, one maxillary second molar, one mandibular first premolar and four mandibular second premolars. A total of 12 teeth had clinically intact crowns and 2 had carious. Eight fractures of maxillary molars occurred in the palatal roots, while one fracture was observed in the distobuccal root. Eleven patients experienced pain from the affected teeth during mastication. Within the limits of this case series, it was concluded that these fractures were related to; root morphology, damaging masticatory habits and excessive occlusal forces.

Notch signalling is of fundamental importance to various processes during embryonic development and in adults. The possible role of Hey1, an important Notch signalling component, in odontoblast differentiation was evaluated in this study. Primary cultured dental pulp cells, derived from upper incisors of 5-week-old Wistar rats, were placed in alpha-modification of Eagle's minimal essential medium supplemented with 10% Fetal Bovine Serum (FBS), and ascorbic acid (AA) and beta-glycerophosphate (beta-GP), with or without dexamethasone, and cultured on dishes coated with collagen type IA for 7 days. Conventional and real-time Polymerase Chain Reaction (PCR) was performed to determine the expression of Notch-related genes and dentin sialophosphoprotein as a marker of odontoblast differentiation. Dentin sialophosphoprotein and Hey1 expression was significantly increased and decreased in the presence of AA + beta-GP compared with controls, respectively. These findings suggest that Hey1 may be a negative regulator in odontoblast differentiation.

Generation of transgenic mice by DNA microinjection has become one of the most important technologies in studying gene function in vivo. Random integration of transgene often results in insertional mutation which may complicate phenotype analysis of transgenic mice and/or create a good opportunity to study the function of endogenous gene. However, the utilization of these potentially valuable resources is hampered due to lack of efficient approaches for rapid identification of multi-copy transgene integration sites. Here we propose two PCR-based approaches to identifying transgene/genome junction sequences. The efficiency of these two strategies was tested in 9 independent transgenic mouse lines. Among them, the transgene in 8 mouse lines was clearly localized to certain chromosome regions. These rapid and efficient approaches will greatly facilitate the study of insertional mutation due to transgene integration.

Background Accreditation of education is very important for maintaining and improving education quality. With the development of modern dental education, more and more attention is being paid to accreditation of dental education in China. Current accreditation of dental education in China is called “dental education evaluation”. By using a systematic review, this paper aims to provide the general profile of the standards and process of dental education evaluation in China (DEEC). Methods A systematic review on DEEC was performed, CAJD and VIP databases were employed to identify all literatures which were relevant to DEEC. Profile and features of DEEC were compared with those of the Accreditation Standards for Dental Education Programs of the USA (ASDEPU). Results The current standards for the evaluation are composed of six modules and twenty-four items, the evaluation process consists of three stages There was some difference between DEEC and its American counterparts. Conclusions Accreditation on dental education is very important for the maintenance and improvement of education quality. As the primary form of dental education accreditation, DEEC is basically suitable for current dental education conditions in China, however, in order to keep pace with the changing conditions, both the standards and actions of DEEC should often be revised.

This study compared the dental curricula at dental schools in China and Japan. A survey was conducted in representative dental schools in China and Japan. It was found that, in China and Japan where dental schools recruit students directly from high schools, more attention is paid to introduction of early professional education. Most dental schools in Japan arrange dental subjects for their students from the first through the fourth years, while in China, only a few dental schools take this path although many of them are currently making changes. It was also discovered that, in both countries, an increasing number of dental schools assign a specific dental subject to the same period with its relevant bioscience or biomedical counterparts, which makes it possible for them to enhance each other reciprocally in a positive way for students and consequently help dental students master the related topics.

Vertical root fractures (VRFs) in teeth without endodontic treatment are relatively uncommon. The diagnosis is based on clinical and radiographic presentations. It might be difficult to detect VRFs in non-endodontically treated molars by conventional radiographs in certain situations because of the limitations of 2D images and many others factors such as the VRFs being in their early stages. Root morphology variation and the orientation of VRFs can influence conventional radiographic detection and the interpretation of a radiolucent fracture line. The four case reports presented here describe and discuss the use of cone-beam computed tomography (CBCT) in successfully diagnosing VRFs based on direct visualization of radiolucent lines, especially those suspected from routine conventional radiographs, as well as their symptoms and clinical findings. CBCT also provides more information on the presence of VRFs.

This case series describes observations of 12 patients who developed horizontal root fractures in non-endodontically treated teeth. Using clinical and radiographic examination, horizontal fractures were observed in eight maxillary first molars, one maxillary second molar, one mandibular first premolar and four mandibular second premolars. A total of 12 teeth had clinically intact crowns and 2 had carious. Eight fractures of maxillary molars occurred in the palatal roots, while one fracture was observed in the distobuccal root. Eleven patients experienced pain from the affected teeth during mastication. Within the limits of this case series, it was concluded that these fractures were related to; root morphology, damaging masticatory habits and excessive occlusal forces.

Notch signalling is of fundamental importance to various processes during embryonic development and in adults. The possible role of Hey1, an important Notch signalling component, in odontoblast differentiation was evaluated in this study. Primary cultured dental pulp cells, derived from upper incisors of 5-week-old Wistar rats, were placed in alpha-modification of Eagle's minimal essential medium supplemented with 10% Fetal Bovine Serum (FBS), and ascorbic acid (AA) and beta-glycerophosphate (beta-GP), with or without dexamethasone, and cultured on dishes coated with collagen type IA for 7 days. Conventional and real-time Polymerase Chain Reaction (PCR) was performed to determine the expression of Notch-related genes and dentin sialophosphoprotein as a marker of odontoblast differentiation. Dentin sialophosphoprotein and Hey1 expression was significantly increased and decreased in the presence of AA + beta-GP compared with controls, respectively. These findings suggest that Hey1 may be a negative regulator in odontoblast differentiation.

In this case report, we present a maxillary second molar variant, which had two palatal roots with two canals and two buccal roots with three canals, including a second mesiobuccal canal. A 44-year-old female patient complained about a tooth crown fracture and severe pain in her right maxillary second molar. A clinical intraoral inspection and radiography were carried out on the tooth, and a diagnosis of chronic apical periodontitis was made. Four roots (two buccal and two palatal) and five canals (three buccal and two palatal) were found. The anatomical variation of the tooth was further confirmed by cone-beam computed tomography, a cone-fit procedure, and a radiograph with a shifted projection angle. Root-canal treatment was performed under an endodontic microscope.