Yong-chun Gu

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INTRODUCTION The radicular groove is clinically significant due to its relevance to onset of inflammatory processes in the periodontal tissues. This study examined anatomic features of radicular grooves by using micro-computed tomography (micro-CT) scans. METHODS Eleven extracted permanent maxillary lateral incisors with radicular grooves were collected(More)
INTRODUCTION The purpose of this study was to quantitatively evaluate the wall thickness of C-shaped canals in mandibular first premolars using micro-computed tomographic imaging. The focus was on the relation between the radicular groove and the mesial canal wall thickness. METHODS A total of 148 mandibular first premolars were scanned by a(More)
A female patient, aged 62 years, unexpectedly swallowed a removable partial denture (RPD) during the supper. The doctor failed to take out the RPD from her stomach under the gastroscope during the emergency treatment at the first day. 2 days later, the PRD blocked the intestinal tract and its metal clasps penetrated the wall of the intestine near the(More)
PURPOSE To explore the prevalence and distribution pattern of the root variations of permanent mandibular first and second molars in an eastern Chinese population. METHODS Cone-beam computed tomography images were collected retrospectively from 261 Chinese patients in Suzhou Stomatological Hospital. The incidences of the root variations were determined.(More)
OBJECTIVE To investigate the anatomic features of the root apexes of permanent three-rooted mandibular first molars. METHODS A total of 122 permanent mandibular first molars of Han Chinese patients were collected. Twenty three-rooted and 25 two-rooted molars were scanned by micro-CT and then reconstructed three-dimensionally. The apical anatomy of the(More)
PURPOSE To study the anatomical features of curved root canals. METHODS According to Nagy's classification,the root canals were divided into 4 types:type I (straight), type C (continuously curved), type J (apically curved) and type S (multicurved). Each type had a sample selected from extracted permanent teeth. Digital radiographs were taken at(More)
OBJECTIVES The purpose of this study was to assess the prevalence, distribution, and intensity of dental caries in the Iron Age population of northern China in order to increase knowledge about the type of food, dietary habit, and social stratification in this Iron Age people. MATERIALS AND METHODS The samples analyzed were dental remains of 1548(More)
PURPOSE To explore the mechanism of failure of ProTaper NiTi handfiles during root canal preparation. METHODS A total of 2061 discarded ProTaper handfiles were collected after clinical use. The files were studied under stero-microscope to determine the type of defect. The fractured files were photographed digitally and the pictures were analyzed by(More)
PURPOSE To investigate the features and rules of preparation errors developed from instrumentation of curved root canals. METHODS 8 curved artificial root canals were prepared with stainless steel K files by the step-back technique,the root canals were digitally photographed,the images were analysed by the software Image-Pro Plus,the shapes and positions(More)
PURPOSE To investigate the prevalence of the Carabelli's trait in a Chinese population. METHODS Direct intraoral examination was conducted on 2758 Han Chinese people. The expression of Carabelli's trait was divided into 5 grades. Software SPSS 13.0 software package was used for statistical analysis. The trait frequency differences between two genders,(More)
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