[A case of high-pressure injection injury of hand complicated with deep chemical burn caused by industrial cement].

This article reports a patient with extensive high-pressure injection injury of the hand combined with deep chemical burn caused by high-pressure injection of industrial cement materials was diagnosed and treated in the Department of Hand Surgery, Xiaolan Hospital Affiliated to Southern Medical University in 2022. The nerves, tendons and blood vessels of the left hand were involved, and the ulnar skin of the left thumb was extensively necrosis, and a large number of extensive cement foreign bodies remained under the skin. Part of the cement was inserted into the joint capsule of the interphalangeal joint. After emergency surgical treatment, the patient was saved successfully, and the wound healed well without chemical poisoning and other related complications, which created conditions for the second stage of flap repair.

[A prevalence survey of cone-beam computed tomography use among endodontic practitioners].

OBJECTIVE: To investigate the clinical application of cone-beam computed tomography (CBCT) among endodontic practitioners, and to analyze the indications and reasonability of CBCT in the diagnosis and treatment of pulpal and periapical diseases. METHODS: The clinical data were collected from patients who visited the Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology and underwent CBCT examination from January to December, 2021. The data with their complete clinical information (including clinical records, radiology request forms/reports, two-dimensional and three-dimensional imaging data) were included. Those who underwent CBCT examination for orthodontic or prosthodontics were excluded. The experience and training background of the endodontic specialists, the number of patients treated in the whole year, the objective and region of interest (ROI) of CBCT examination, technical parameters, such as machine type, field of view (FoV) and radiographic reports were collected and analyzed to evaluate the impact on diagnosis. Wilcoxon and Mann-Whitney tests were used to compare the distribution of CBCT ROI. Chi-squared test and pairwise comparison were used to compare the application of CBCT by endodontic specialists with different clinical experience (senior, middle and junior). RESULTS: In 2021, a total of 3 308 CBCT scans were prescribed by 61 endodontic specialists who treated 34 952 patients throughout the year. 3 218 patients (male ∶female about 1 ∶2) amounting for 10% of the patients treated in the whole year who received CBCT scans with an median age of 35 years (28, 49). Around 98% CBCT examinations were performed after clinical examination and two-dimensional periapical radiographs were taken. The FoV of CBCT scanning less than 10 cm×10 cm accounted for 96% of the total number of the images. Among the 3 308 CBCT scans, 83% of the ROI were in posterior teeth, with a higher number of anterior teeth (Z=-2.278, P < 0.05). Maxillary and mandibular first molars accounted for 35% of the examined teeth. The objectives of CBCT scanning included three aspects: clarifying clinical diagnosis, guiding surgical and non-surgical endodontic treatment (including management of endodontic complications), and outcome assessment, accounting for 1 111 (34%), 1 745 (54%), 311 (10%), respectively. and the others 2%. In the diagnosis process, CBCT was mainly used for the diagnosis of chronic periapical periodontitis, root fracture, root resorption and dental trauma. In the study, 353 CBCT were used in the diagnosis of root fracture, with a positive diagnosis rate of 35% (125/353). 846 CBCT used to reveal the anatomy of the root canal system, of which 297 cases were used to find missed/extra canals after treatment failure, and 58% (171/297) were used to confirm the missed/extra canals. In the management of complications or errors, CBCT was mainly used to assist the diagnosis of perforation and to locate the separated instruments. In the study, 311 CBCT scans were used for outcome assessment, including 240 cases related to non-surgical treatment and 71 cases related to surgical endodontic treatment for follow-up or presence of clinical symptoms, and persistent lesions on 2D films. Among the 61 endodontic specialists who used CBCT, 23 (45%) were with senior experience, 15 (30%) with middle experience, and 23 (25%) with junior experience. The proportion of senior or junior experience prescribing CBCT examination was 10%, higher than that of middle experience (8%, χ12=39.4, χ22=29.1, P < 0.001). The application rate of chief endodontists was 18%, which was higher than that of associate chief endodontists (9%, χ12=139.4, P < 0.001). 31% (1 109/3 308) cases of diagnosis or treatment plans were changed after CBCT was taken. CONCLUSION: Use of CBCT in endodontic practice could provide more clinical information, which is helpful for diagnosis, accurate treatment and prognosis evaluation.

[Relationship between auditory hallucination and regional homogeneity of functional magnetic resonance imaging in first-episode childhood and adolescence-onset schizophrenia].

Objective: To investigate the characteristics of regional homogeneity (ReHo) of the resting-state magnetic resonance imaging (fMRI) in first-episode childhood and adolescence-onset schizophrenia (CAOS) and to analyze the relationship between the severity of auditory hallucinations and ReHo. Methods: Seventy-nine cases of first-episode CAOS patients (case group) aged 10 to 16 were collected from October 2017 to December 2019 in the Second Affiliated Hospital of Xinxiang Medical University. There were 28 males and 51 females with a mean age of (14.1±1.3) years. And meantime, 32 healthy children matched with the patients in baseline data were selected as healthy controls (HCs). The patients with CAOS were divided into three groups according to the auditory verbal hallucinations (AVH) assessment of positive symptoms scale (SAPS): non-AVH group (0-1 point), 20 cases; mild-to-moderate AVH group (2-3 points), 36 cases; severe AVH group (4-5 points), 23 cases. The severity of psychiatric symptoms was evaluated using the Positive and Negative Syndrome Scale (PANSS). ReHo analysis was performed on the resting state fMRI scan data of all subjects. Covariance analysis (ages was used as a covariate) was performed between the case group and the HCs, and the three case groups were analyzed to find the different brain areas. Finally, covariance analysis (ages as a covariate) was performed on ReHo values between the case group and the HCs, and among the three groups of patients. Correlation analysis was conducted between the ReHo values in different brain regions and PANSS scores, as well as AVH scores. Results: Compared with the HCs, the decreased ReHo of patients were mainly located in the left superior frontal gyrus, right superior temporal gyrus, left central anterior gyrus, and right central anterior gyrus (all P<0.05). Besides, the ReHo deficits were in the right superior temporal gyrus, left middle frontal gyrus, precuneus lobe, and left central anterior gyrus among the three groups (all P<0.05). Moreover, the severe-AVH group showed decreased ReHo values in precuneus lobe compared with the non-AVH group (P<0.05), and showed decreased ReHo values in left middle frontal gyrus and left central anterior gyrus compared with the mild-to-moderate AVH group (both P<0.05). Furthermore, the ReHo in the right superior temporal gyrus and the left anterior central gyrus were negatively correlated with the AVH score (rs=-0.34, -0.32, P<0.05); and the positive symptom score was negatively correlated with the ReHo in the right superior temporal lobe (r=-0.23, P<0.05). Conclusion: Firstly, decreased ReHo is found in multiple brain regions in CAOS. Secondly, the occurrence of auditory hallucinations may be related to the abnormal activity of local neurons in the resting state. Consequently, Abnormal brain function may be the underlying neural basis for the first-episode CAOS.

The recovery effect of proanthocyanidin on microtensile bond strength to sodium hypochlorite-treated dentine.

AIM: To evaluate the recovery effect of proanthocyanidin (PA) on microtensile bond strength (µTBS) to sodium hypochlorite (NaOCl)-treated dentine. METHODOLOGY: Fifty-five freshly extracted third molars with intact dental crowns, no caries or restorations were sectioned to expose a sound middle layer of dentine and were randomly divided into 11 groups. In the blank control group, dentine surfaces were immersed in deionized water for 20 min. In the negative control group, dental surfaces were immersed in 5.25% NaOCl for 20 min. In the other nine experimental groups, after immersion for 20 min in 5.25% NaOCl, followed by PA (5%, 10%, or 15%) treatment for 1, 5 min or 10 min. The NaOCl solution was renewed every 5 min. Then dentine surfaces were bonded using SE bond. Bonded samples were sectioned into dentine-resin sticks (n = 45) for microtensile bond strength testing (MPa). Failure modes were observed and classified into three types with a stereomicroscope. Microtensile bond strength data were analysed using one-way anova. The confidence interval test was performed to analyse the recovery effect of PA on bond strength to NaOCl-treated dentine. The chi-squared test was used to analyse failure mode distribution. RESULTS: After use of 5.25% NaOCl for 20 min, microtensile bond strength in the negative control group decreased significantly compared with that of the untreated group (P < 0.05). After a recovery treatment of 10% PA for 10 min or 15% PA for more than 5 min, the bond strength was restored to at least 90% of baseline (P < 0.05). No recovery effect on bond strength was detected after the application of 5% PA for 1 min (P > 0.05). Adhesive fracture was found to be the most common failure mode in the NaOCl-treated group. After the recovery application of PA, the proportion of mixed failures increased significantly (P < 0.05). CONCLUSIONS: Microtensile bond strength to NaOCl-treated dentine recovered after the application of either 5% PA for more than 5 min or 10% or 15% PA for more than 1 min. The application of PA before an adhesive procedure may immediately restore the compromised bond strength of NaOCl-treated dentine.

[Effects of different methods on drying root canal by near-field microwave detection system].

OBJECTIVE: To set up near-field microwave detection system, to evaluate the accuracy of measuring water and to compare the effects of different methods on drying root canal. METHODS: Known and quantitative distilled water in Eppendorf tube and root canal was detected by near-field microwave detection system which was set up first. The microwave reflection coefficient was recorded so as to evaluate the accuracy of the measuring water. 12 single-rooted mandibular premolar teeth with apical matureness and a curvature less than 10° were decoronated, leaving roots 14 mm in length. After instrumentation to F3, the root canals were air-dried and injected with 10 µL distilled water each. Then all the root canals were assigned to 4 groups (n=12) according to different methods on root canal drying. Near-field microwave detection system was used to detect the change of water after air-drying and root canal drying so as to evaluate the effects of different root canal drying methods: (1) negative control group, the canals were injected with 10 µL distilled water and no root canal drying method was performed; (2) paper points drying experimental group, four #60 paper points were used to blot-dry the middle and upper part of the canal, followed by #40 paper points blot-drying the apical area. The above step was repeated with the tip of paper point that appeared with no water under microscope as finished; (3) 95% (volume fraction) ethanol drying experimental group, after the distilled water was removed with paper points (similar to paper points experimental group), 10 µL 95% ethanol was injected into the canal and was left in place for 10 s, then paper points were used to dry the canal; (4) 70% (volume fraction) isopropyl alcohol drying experimental group, after the distilled water was removed with paper points (similar to paper points experimental group), 10 µL 70% isopropyl alcohol was injected into the canal and was left in place for 10 s, then paper points were used to dry the canal. The linear correlation analysis was used to test the accuracy of the measuring water by near-field microwave detection method and physical measurement. The Pearson correlation coefficient was calculated based on the data. The effects of different methods on drying root canal were analyzed by Chi square test. RESULTS: The R2 for the microwave reflection coefficient and the physical measurement of the water in Eppendorf tube and root canal were 0.991 and 0.970. The microwave reflection coefficient in all the experimental groups showed significant difference (P<0.05). After drying with paper points, the residual water was the most, and the microwave reflection coefficient was the highest: 0.023. While after 70% isopropyl alcohol drying root canal, the residual water was the least with the microwave reflection coefficient 0.006, showing that the effect of drying was the best. CONCLUSION: Near-field microwave detection system could detect the change of water in root canal. The effect of root canal drying by 70% isopropyl alcohol was superior to 95% ethanol and paper points.

[Construction of swept source optical coherence tomography imaging system for root canal endoscopy and application in diagnosis of root fractures].

OBJECTIVE: To construct swept source optical coherence tomography (SS-OCT) imaging system for root canal endoscopy, and to evaluate the accuracy of diagnosing artificial root fractures. METHODS: An ultra-high-speed (40 kHz) swept laser source was developed based on the piezoelectric tuning filter and the Fourier domain mode locking (FDML) swept laser technology (patent number: 200620135940.2). Ultra-miniature gradient index lens technology (patent number: 201320241218.7) was used to create a thin endoscopic probe with a diameter of 0.86 mm for real-time image transmission. The SS-OCT light source had a wavelength of 1 310 nm and a bandwidth of 100 nm. The axial and transverse image resolutions were 15 µm and 25 µm, respectively. Artificial fractures were created on human mandibular premolars with single root and the premolar roots were prepared to 41 horizontal sections (1 mm thick). 27 root sections with fractures (width: 52-284 µm) and 14 the sections without fractures were observed under an optical stereomicroscope with a cold light source as the gold standard. The horizontal root sections were scanned by self-developed SS-OCT imaging system for root canal endoscopy with a central wavelength of 1 310 nm and bandwidth of 100 nm. The data were reconstructed with 30 µm thick slices at an interval of 30 µm. Two observers, a radiologist and an endodontist, were trained and independently evaluated all the reconstructed images blindly. The diagnostic performance of SS-OCT imaging system was calculated, and statistical analysis was performed. RESULTS: SS-OCT root canal endoscopic imaging system composed of high-speed swept laser source, fiber coupler, endoscopic probe, reference arm and differential detector. Root sections could be scanned by SS-OCT and imaged in realtime at a depth of 1 to 2 mm. The kappa value for interobserver agreement was 0.792, and the intraobserver agreement was 1.000 and 0.709 for two observers respectively. All of 27 fractured root sections and 12 of 14 root sections without fractures were accurately diagnosed while 2 unfractured root sections were misdiagnosed. The sensitivity was 1.000 and the specificity was 0.857 for diagnosis of artificial root fractures by SS-OCT. The positive predictive value (PPV), negative predictive value (NPV) and the overall accuracy rate were 0.931, 1.000 and 0.951 respectively. CONCLUSION: The swept source optical coherence tomography imaging system for root canal endoscopy is a promising imaging method for observing root fractures．.

[Relationship between periodontitis and osteoporosis in postmenopausal women].

OBJECTIVE: To explore the relationships of periodontal parameters, cortical width on mental foramen and osteoporotic condition in postmenopausal women. METHODS: Ninetyeight postmenopausal women between 50 to 65 years old were recruited. General conditions, such as age, menopausal age, duration of menopause, and body mass index (BMI) were recorded. Periodontal parameters were examined, including oral hygiene index simplified (OHI-S), probing depth (PD), clinical attachment loss (CAL), gingival recession (GR) and bleeding on probing (BOP). Panoramic radiograph was taken and the cortical width (CW) of mental foramen was measured on images. The examiner was celebrated. Bone mass density (BMD) of left hip and lumbar spine was assessed using standardized dual energy X-ray absorptiometry. According to World Health Organization, based on the T-score of BMD (difference of the measured BMD and the mean value of young white women in terms of standard deviations), the subjects were divided into osteoporotic group (T-score<-2.5) and non-osteoporotic group (T-score≥-2.5). These parameters were compared between the groups. RESULTS: The number of osteoporotic group was 47 (47.96%). Ages and duration of menopause were significantly different between the groups. Osteoporotic group presented older ages [(59.64±4.58) years vs. (56.94 ± 4.26) years, P<0.05], and longer duration of menopause [(10.17± 5.37) years vs. (6.02 ±4.48) years, P<0.05]. There was no significant difference in menopausal age and BMI between the groups. BOP% was statistically significantly higher in osteoporotic group (29.43±21.12) than in non-osteoporotic group (21.43±17.09), with a P-value of 0.046. The other periodontal parameters, including OHI-S, PD, CAL, and GR were not statistically significantly different in the groups. The CWs were statistically significantly lower in osteoporotic group compared with non-osteoporotic group, with a P-value of 0.001. The mean values of CWs were (3.61±1.04) mm (osteoporotic group) and (4.25±0.77) mm (non-osteoporotic group), respectively. CONCLUSION: The study demonstrated absence of a significant association between periodontal parameters and BMD. However, the CWs were found to be related with the BMD, which may be used to detect BMD abnormal in maxillofacial imaging. The dentists should pay attention not only to the oral health, but also to the general bone mass density, which may be detected on panoramic images.

USF1 gene polymorphisms may associate with the efficacy and safety of chemotherapy based on paclitaxel and prognosis in the treatment of ovarian cancer.

This study was supposed to investigate the correlation between the functional single nucleotide polymorphisms (SNPs) (rs2516839 and rs3737787) in USF1 gene and the efficacy and safety of paclitaxel-based chemotherapy and prognosis in the treatment of ovarian cancer (OC). In total 100 OC patients were selected and divided into the sensitive group and the resistantgroup according to the tumor response to paclitaxel-based chemotherapy after surgery, and the incidence of observed and recorded toxic reaction. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was applied to test the polymorphisms of rs2516839 and rs3737787 in USF1 gene after extraction of DNA. The correlation between USF1 gene polymorphisms and paclitaxel-based chemotherapy resistance was analyzed using Logistic regression analysis. Stratified analysis was used to test the incidence of toxic reaction in OC patients. Cox proportional hazard model was adapted to make a multiple-factor survival analysis. Significant differences exhibited in the genotype and the allele frequencies of rs2516839 between the sensitive and resistant groups, which showed no obvious difference in the genotype and allele frequencies of rs3737787. OC patients carrying the GA+AA genotype had higher incidence of serious toxic reaction than those carrying the GG genotype. Physical status score, tumor type, maximum tumor diameter and rs2516839 were the independent risk factors for the prognosis of OC patients. Taken together, our results suggest that the rs2516839 polymorphism in USF1 gene may associate with the efficacy and safety of paclitaxel-based chemotherapy and prognosis in the treatment of OC.

[Cleaning efficacy of different solvents on sealer-contaminated dentin surface].

OBJECTIVE: To evaluate the influence of an epoxy resin-based sealer on the bond strength of adhesive resins to dentin and the cleaning efficacy of different solvents in removing sealer residues. METHODS: The occlusal enamel of 25 freshly extracted human third molars without caries were removed to expose flat surfaces of dentin. The teeth were randomly divided into five groups according to the treatment received: For negative control group, the dentin surfaces were not contaminated with AH-Plus; For the other 4 experimental groups, the samples were contaminated with AH-Plus for 5 min and different measures were taken: For positive control group, the sealer were wiped with dry cotton pellets; For solvents experimental groups: cotton pellets saturated with 95% (volume fraction) ethanol, 99.5% (volume fraction) acetone or 99% (volume fraction) amyl acetate were used to wipe the sealer until the surface appeared clean when viewed through a stereomicroscope under ×10 magnification, then rinsed with de-ionized water for 3 s. After sealer removal, a self-etching adhesive system was applied on the surfaces with resin composite. The samples were sectioned into 1.0 mm×1.0 mm stick specimens (n=45) for microtensile test. Failure modes at the dentin-resin interface were observed using a stereomicroscope. The samples were sectioned into 1.0 mm piece specimens (n=4) for scanning electron microscope observation. The microtensile bond strength data were analyzed by one-way ANOVA. Chi-square test were used to analyse the failure modes between the groups. RESULTS: There was significant difference among the five groups (P<0.001). For dry cotton pellet group (38.69±8.60) MPa and the ethanol group (37.14±12.01) MPa, the microtensile bond strength significantly declined when compared with negative control group (43.86±7.99) MPa (P<0.05). No significant difference of bond strength was found between the dry cotton pellet group and the ethanol group (P=0.426). There was no statistical significant difference among acetone group, amyl acetate group and negative control group (P>0.05). The bond strength of acetone group and amyl acetate group were (45.94±10.37) MPa and (43.99±7.01) MPa, respectively. The ethanol group exhibited lower bond strength than that of acetone group and amyl acetate group (P<0.05). Scanning electronic microscope observation revealed that in dry cotton pellet group and ethanol group, the resin tags were short and loose. Moreover, sealer residues were identified in the interface in the ethanol group samples, while the resin tags in the acetone and amyl acetate group were as dense and uniform as in negative control group. The distribution of failure modes showed no significant difference in the five groups (P=0.086). CONCLUSION: The microtensile bond strength of dentin to composite resin was lower after exposure to sealer. Compared with ethanol and dry cotton pellets, the cleaning effect of acetone and amyl acetate on sealer-contaminated dentin surface were better.

[A prognostic model for assessment of outcome of root canal treatment in teeth with pulpitis or apical periodontitis].

OBJECTIVE: To present a prognostic model for evaluating the outcome of root canal treatment in teeth with pulpitis or apical periodontitis 2 years after treatment. METHODS: The implementation of this study was based on a retrospective study on the 2-year outcome of root canal treatment. A cohort of 360 teeth, which received treatment and review, were chosen to build up the total sample size. In the study, 143 teeth with vital pulp and 217 teeth with apical periodontitis were included. About 67% of the samples were selected randomly to derive a training date set for modeling, and the others were used as validating date set for testing. Logistic regression models were used to produce the prognostic models. The dependent variable was defined as absence of periapical lesion or reduction of periapical lesion. The predictability of the models was evaluated by the area under the receiver-operating characteristic (ROC) curve (AUC). RESULTS: Four predictors were included in model one (absence of apical lesion): pre-operative periapical radiolucency, canal curvature, density and apical extent of root fillings. The AUC was 0.802 (95%CI: 0.744-0.859). And the AUC of the testing date was 0.688. Only the density and apical extent of root fillings were included to present model two (reduction of apical lesion). The AUC of training dates and testing dates were 0.734 (95%CI: 0.612-0.856) and 0.681, respectively. As predicted by model one, the probability of absence of periapical lesion 2 years after endodontic treatment was 90% in pulpitis teeth with sever root-canal curvature and adequate root canal fillings, but 51% in teeth with apical periodontitis. When using prognostic model two for prediction, in teeth with apical periodontitis, the probability of detecting lesion reduction with adequate or inadequate root fillings was 95% and 39% 2 years after treatment. CONCLUSION: The pre-operative periapical status, canal curvature and quality of root canal treatment could be used to predict the 2-year outcome of root canal treatment.

[Detection of root cracks after root canal preparation using rotary NiTi systems by optical coherence tomography (OCT) scan].

OBJECTIVE: To evaluate the accuracy of optical coherence tomography (OCT) in detecting root cracks after root canal instrumentation using histological gold standard. METHODS: Twenty complete extracted human mandibular incisors that were free of caries, calculus, and root treatment were chosen and accessed coronally with a diamond bur, then mounted in resin blocks with alginate impression material using simulated periodontal ligaments, and the apex was exposed 3 mm. The teeth were stored in water at room temperature. Then the teeth were then instrumented to the major apical foramen (AF) at #30/0.09 using ProTaper Universal rotary nickel titanium system (Dentsply Maillefer, Ballaigues, Switzerland), irrigation with 1% sodium hypochlorite (NaOCl) by using a 26-gauge needle followed after each instrument. The apical root was scanned with 360° of rotation by Swept-Source Optical Coherence Tomography (SS-OCT) (wavelength: 1 310 nm, scan rate: 20 kHz, axial resolution: 16 µm) with driving device (stepper motor and lifting platform). The reconstruction images of axial planes 1, 2 and 3 mm from the apex were examined and the root cracks were blindly diagnosed by two observers. The horizontal section was performed at 1, 2 and 3 mm from the apex using low speed disc saw (Leica SP1600, Wetzlar, Germany). The presence of cracks was noted under an optical stereomicroscope (ZOOM-630E) with a cold light source using as gold standard to evaluate the accuracy of OCT in detecting root cracks after root canal instrumentation. RESULTS: After canals instrumentation with ProTaper Universal rotary nickel titanium system to #30/0.09, root cracks were detected in 9 of 20 teeth by histological examination. Crack lines were observed on 13 of 60 horizontal sections and cracks on 12 of the 13 sections were detected by OCT. No cracks were observed in the other 47 of the 60 horizontal sections,none of which was misdiagnosed by OCT. The overall accuracy rate for detection of root cracks with OCT was 0.983, the sensitivity was 0.923, the specificity was 1.000, the positive predictive value (PPV) was 1.000 and the negative predictive value (NPV) was 0.979. CONCLUSION: OCT may be a promising nondestructive imaging method for diagnosing root canal cracks after canal instrumentation.

[Computer aided design and three-dimensional printing for apicoectomy guide template].

OBJECTIVE: To establish an apicoectomy guide template design and manufacturing method, based on multi-source data fusion, computer aided design (CAD) and fused deposition modeling (FDM). The feasibility of the guide template was preliminary evaluated by the in vitro model experiment. METHODS: An extracted upper anterior tooth, after root canal treatment, was optical scanned, after which the extracted upper anterior tooth was poured in an apicoectomy plaster model. Cone-beam computed tomography (CBCT) scanning of the apicoectomy plaster model was performed, after which optical scanning of the plaster model for apical resection surgery was carried out. All of the relevant CBCT and optical scanning data of the extracted upper anterior tooth and the apicoectomy plaster model were introduced into the Geomagic Studio 2012 software. The multi-source data fusion technology was used to virtually simulate the three-dimensional positional relationship of the extracted tooth, the dentition, the alveolar bone and the gingival, based on which, the three-dimensional design of the apicoectomy guide template was completed in the Geomagic Studio 2012 software. With the technology of fused deposition modeling, the apical resection surgical guide template was three-dimensionally printed with the material of polylactic acid (PLA). Under the guidance of the surgical guide template, the root apical resection was performed on the plaster model. After the apicoectomy, the extracted upper anterior tooth was taken off from the apicoectomy plaster model and then was given the optical scanning. The apical resection length and angle were calculated by the function of distance measurement and angle measurement, and the results were compared with the preset values. RESULTS: The length of the apical resection was 2.88 mm along the direction of the long axis of the tooth, which was 0.12 mm lower than the preset 3 mm. The included angle between the apical resection plane and the long axis of the tooth was 77.9°, 12.1° lower than the preset 90°. CONCLUSION: This study successfully established a digital design and production method of apicoectomy guide template by combing the multi-source data fusion, CAD and FDM technology. The design route and the production method are feasible. The study will provide a technology and methodology reference for the development of domestic special software for the digital design of apicoectomy guide template.

[Effect of long-term deep slow-wave sleep deprivation on the reproductive system in male rats].

Objective: To investigate the effect of long-term deep slow-wave sleep deprivation on the gonad axis, sperm abnormality rate, and structure of the testis in male rats and possible mechanisms. Methods: A total of 30 specific pathogen-free male Wistar rats aged 5 weeks were randomly divided into slow-wave sleep deprivation group 1 (SD1 group) , slow-wave sleep and sleep time deprivation group 2 (SD2 group) , and control group, with 10 rats in each group. The flower pot method was used to establish a model of sleep deprivation. In addition to 12-hour sleep deprivation at night, the rats in the SD1 group were given interference once every 24 minutes, and those in the SD2 group were deprived of sleep for 8 minutes every 24 minutes; the rats in the control group were given 12-hour light illumination and then placed in dark environment for 12 hours. All rats were sacrificed by exsanguination from the femoral artery, and the testis, the epididymis, and blood were collected for analysis. Sperm abnormality rate and sperm motility rate were measured, and cauda epididymal sperm counting was performed. ELISA was used to measure the serum levels of testosterone (T) , follicle-stimulating hormone (FSH) , and luteinizing hormone (LH) . Results: Compared with the control group, the SD2 group had a significant increase in organ coefficient of the epididymis (P<0.05) and a significant reduction in sperm motility rate (P<0.05) . There were significant differences between the SD1 group and the SD2 group in the increase in sperm abnormality rate (P<0.05) and the reduction in cauda epididymal sperm count (P<0.05) . The levels of FSH and T tended to increase, and the level of LH tended to decrease. Pathological examination showed degeneration and vacuolization of a small amount of spermatogenic cells in the SD1 group; in the SD2 group, there were significant degeneration, edema, and vacuolization of most spermatogenic cells, some spermatogenic cells were observed in the lumen, and there were no sperms in the lumen. Conclusion: Long-term deep slow-wave sleep deprivation impairs the structure of the testis, affects sperm motility rate and sex hormones, and increases the risk of sperm abnormality.

[Influence of surface treatment with sodium hypochlorite solution on dentin bond strength].

OBJECTIVE: To evaluate the influence of sodium hypochlorite (NaOCl) solution used during root canal therapy on dentin bond strength. METHODS: In the study, 15 freshly extracted human third molars with complete dental crowns, caries and filling-free were selected. The occlusal enamel was removed perpendicular to the long axis of the tooth to expose middle flat surfaces of sound dentin. The occlusal dentin surfaces were then polished using 600-grit silicon papers for 1 min and rinsed with deionized water for 1 min. The teeth were randomly divided into three groups according to the treatment received: group A (negative control group), the samples were immersed in deionized water for 20 min; group B, the dentin surfaces were immersed in 2.50% NaOCl solution for 20 min, with the solution being renewed every 5 min; group C, the dentin surfaces were immersed in 5.25% NaOCl solution for 20 min, with the solution being renewed every 5 min. All the treated dentin surfaces were bonded using a self-etching adhesive system (SE bond) with a 5 mm in height resin composite (AP-X). After storage in deionized water at 37 °C for 24 h, the adhesive samples were sectioned longitudinally to produce 1.0 mm×1.0 mm stick specimens(n=45) for micro-tensile bond strength testing (MPa). Failure modes (adhesive failure, cohesive failure or mixed failure) at the dentin-resin interface were observed using a stereomicroscope. The micro-tensile bond strength data among the three groups were analyzed by a one-way ANOVA, then the Post-hoc test(LSD) was employed for pairwise comparison. The distribution of failure modes among the groups were analyzed by chi-square test. RESULTS: Significant decreased bond strength values were found for the 2.50% NaOCl-treated group (26.04±5.74) MPa and 5.25% NaOCl-treated group (24.46±3.77) MPa when compared with the strength of negative control group (48.71±7.77) MPa,P=0.000. Compared with the negative control group, themicro-tensile bond strength of the 2.50% NaOCl-treated group and 5.25% NaOCl-treated grouphad dropped by 46.5% and 50.2%. However, there was no significant difference of bond strength between the 2 NaOCl-treated groups (P=0.214). The distribution of failure modes showed significant difference in all the three groups (2=56.324, P=0.000). The mixed failure (68.9%) was the most mode of fracture in the negative control group, followed by adhesive failure(24.4%), and the cohesive failure was least(6.7%). The proportion of adhesive failure mode was higher in NaOCl-treated groups than in negative control group (P=0.000). There was no significant difference of the distribution of failure modes between the 2.50% NaOCl-treated group and 5.25% NaOCl-treated group(P=0.197), and there was no cohesive failure mode detected in the two groups. CONCLUSION: The micro-tensile bond strength of dentin to composite resin was lower after exposure to NaOCl solution.

[Impact of apical preparation diameter on fracture resistance of mandibular premolar roots].

OBJECTIVE: To compare the fracture resistance of roots of mandibular premolar with different apical preparation diameters. METHODS: Sixty single-rooted single canal permanent mandibular premolar teeth extracted newly for orthodontic reason without immatureness, fracture or cracks were selected, with a curvature less than 10°, and internal length: short diameter of less than 2 at a level 5 mm from the apex. All the teeth were decoronated, leaving roots 13 mm in length. The initial apical file size for the teeth was ≤15#. The roots were assigned to 6 groups based on weights with random block design. Group A: blank control group, no instrumentation was performed. Groups B-F: the master apical file (MAF) was 40#, 45#, 50#, 55# and 60#, respectively. In the five experimental groups the roots were instrumented using hand files with step-back technique at 1 mm increments, resulting in a taper of 0.05. The irrigant used was distilled water. After mounted in acrylic resin, all the teeth were subject to vertical loading using an Instron testing machine until fractured. The occurrence of fractures was detected when the applied load suddenly decreased. The fracture load values and fracture modes were recorded. One-way ANOVA and post-hoc Tukey test were used to determine the difference of fracture load values between the groups (P<0.05). Chi-square tests were used to compare the modes of root fracture. RESULTS: Five experimental groups exhibited lower fracture load values than that of control group [(1 444±155) N]. The mean fracture load values for roots instrumented to an apical diameter of 50# [(1 027±128) N], 55# [(994±150) N] and 60# [(983±166) N] were significantly lower than that of control group and 40# group [(1 339±131) N] and 45# [(1 287±144) N] (P<0.05). Buccal-lingual fracture, mesio-distal fracture and compound fracture occurred 55%, 13% and 32%, respectively. No difference of fracture mode was detected in the six groups. CONCLUSION: The fracture resistance reduced significantly when the roots were instrumented to an apical diameter of 50# or larger.

[Retroperitoneal laparoscopic with renal pedicle rotation for partial nephrectomy of ventro-renal tumor].

OBJECTIVE: Retro-laparoscopic partial nephrectomy is a challenge for ventro-renal tumors, especially hilar tumors. The tumors are partial or entirely out of operative field and there is blind space for operation. To solve this problem, a set of techniques including renal pedicle rotation is developed. METHODS: A set of techniques including renal pedicle rotation, double-layer suture, early artery unclamping for retro-laparoscopic nephrectomy for ventro-renal tumors, especially hilar tumors were developed. Hilar tumors were located anteriorly to the angle of the renal and renal arteries and in contact with the anterior surface of the renal artery. The evaluation of the outcomes included the operation time, warm ischemia time, estimated haemorrhage, surgical margin, renal function after operation, and complications. This study reviewed the data of 28 patients with ventro-renal tumor, including 15 patients with complex hilar tumors. RESULTS: The average tumor size was (3.8±0.5) cm. The average R.E.N.A.L score was 8 (ranging from 7 to 9). The average warm ischemia time was (23.8±4.7) min, and suture time was (26.2±6.5) min, and operation time was (124.1±12.1) min. The median hospital stay was 4 days and the average estimated haemorrhage was (139.1±54.0) mL. All the surgeries were operated under laparoscope and no surgery switched to open surgery. Seven patients developed Clavien Dindo I-II complications after operation. Three patients (10.7%) developed collective system damage and received repair of collective system in time and three patients (10.7%) developed slightly gross hematuria (Clavien-Dindo I). Two patients developed wound infection (Clavien-Dind II). Three patients (10.7%) got renal vein clamped because of capillary hemorrhage from basilar part of tumors. There were 14 patients received early unclamping of renal artery, and no obvious renal vessel damage was found. There were statistically significant differences between the serum creatinine levels (P<0.05) and the estimated glomerular filtration rates (P=0.02) before and after surgery. All the patients' serum creatinine levels were in normal range and no patient needed regular dialysis. There was no positive surgical margin and the median follow-up was 7 months without local recurrence or distant metastasis. CONCLUSION: It is safe and effective to apply renal pedicle rotation technique in retro-laparoscopic partial nephrectomy for ventro-renal tumors. The short-term follow-up results are optimistic, but long follow-up is required.

[Comparison of periapical radiography and cone-beam computed tomography in endodontic treated teeth for assessment of periapical lesions].

OBJECTIVE: To compare the assessments of the presence or absence and the changes of post-treatment periapical lesions using periapical radiographs versus cone-beam computed tomography (CBCT). METHODS: Imaging records were selected from a sample of 233 radiographic examinations (including periapical radiographs and CBCT) of patients with chronic apical periododontitis who received treatment and review in Department of Cariology and Endodontology of Peking University School of Stomatology. After testing the inter-observer and intra-observer agreement, two observers determined the presence or absence of a periapical lesion and classified the changes of lesions in 4 categories: absence, reduction or enlargement of lesion, or uncertain. The differences between CBCT and periapical radiographs in detecting the presence or absence and the changes of periapical lesions were compared using McNemar test and Fisher's exact test respectively. RESULTS: In the study, 233 teeth were assessed with both periapical radiographs and CBCT images. Periapical lesions were detected in 178 teeth on CBCT scans and in 146 teeth on periapical radiographs. CBCT images revealed a significantly larger number of lesions than were revealed by periapical radiographs (P<0.01). There was disagreement on the changes of lesions between the two radiological technologies in 25% teeth, and the difference was statistically significant (P<0.01). CONCLUSION: Significant differences were observed between periapical radiographs and CBCT in detection of post-treatment periapical lesions and assessment of the changes of periapical lesions.

[Fractional amplitude of low-frequency fluctuations in childhood and adolescence-onset schizophrenia: a resting state fMRI study].

Objective: To explore the whole brain activity features of childhood and adolescence-onset schizophrenia using resting state fMRI. Methods: A total of 63 childhood and adolescence-onset schizophrenia patients (patients group), admitted to the second affiliated hospital of Xinxiang Medical University from October 2013 to October 2015 and fulfilled our inclusion criteria, and 39 healthy controls with age, sex and education matched (control group) were enrolled, then a resting-state fMRI scan was conducted for each participant. Fractional amplitude of low-frequency fluctuations (fALFF) approach was used to explore the differences of resting-state brain function between patients and controls. Results: Compared with the healthy control group, patients group showed significantly decreased fALFF in left superior temporal gyrus and parietal lobe (MNI coordinate: x=-42, -57; y=-3, -21; z=-12, 9; voxels: 22, 32; t=-4.792 3, -5.269 7; Alphasim corrected, corrected P<0.05); patients group showed significantly increased fALFF in left frontal lobe and medial frontal gyrus, right superior frontal gyrus, Postcentral Gyrus, caudate, (MNI coordinate: x=-42, -21, 12, 27, 15; y=54, 39, 48, -18, 15; z=0, 21, 33, 30, 9; voxels: 12, 21, 17, 28, 18; t=4.784 8, 4.90 7, 4.861 5, 5.444 1, 4.270 4; Alphasim corrected, corrected P<0.05). When included age as a covariant, the analysis found that the brain region with significant fALFF change was the left thalamus with decreased fALFF (MNI coordinate: x=-6, y=-12, z=24; voxels: 9; t=-4.268 4; Alphasim corrected, corrected P<0.05) in patients group, while for other brain regions, there was no obvious change in the fALFF, compared with healthy group. Conclusion: Compared with control group, the results indicate that there are intrinsic brain activity abnormalities of some brain regions in childhood and adolescence-onset schizophrenia.

Two novel missense mutations of ATP2A2 in two Chinese patients with sporadic Darier disease.

Darier disease (DD) is a rare autosomal dominant skin disorder with characteristic abnormal keratinization and acantholysis. The causative gene, ATP2A2, is located on chromosome 12, and encodes a sarco/endoplasmic reticulum calcium pump ATPase (SERCA2). Two Chinese patients with sporadic DD participated in this study. Genomic sequence analysis identified two novel missense mutations (c.742C>A and c.2098A>G) in the ATP2A2 gene. Our findings provide an additional ATP2A2 mutation causative for DD development, and new lines of evidences for the understanding of genotype-phenotype correlations.

Detection and measurement of artificial periapical lesions by cone-beam computed tomography.

AIM: To test the ability of periapical radiography (PA) and cone-beam computed tomography (CBCT) to determine the presence/absence of periapical lesions and examine the reliability of volumetric measurements of periapical lesions on CBCT scans. METHODOLOGY: After tooth extractions in human mandibles, bone defects were cut at the base of extraction sockets to mimic periapical bone lesions. The teeth were then returned into the extraction sockets. Sixty-three roots of anterior teeth, premolars and molars with artificial periapical lesions and 37 roots without lesions were examined with PA and CBCT. Presence/absence of periapical lesion was noted. The CBCT-based volume of each lesion (Vct) was measured using Amira software 5.4 (Visage Imaging GmbH, Berlin, Germany). A replica of each lesion was created using silicone impression material, and the volume of the replica was measured using a water displacement method, representing the physical volume of the lesion (Vp). Regression analysis was used to test the correlation between the Vp and Vct values. RESULTS: The positive and negative predictive values and accuracy for CBCT in diagnosing periapical lesions were all 1, compared with 1, 0.64 and 0.79 for PA diagnosis. Twenty-one (33%) lesions were undetected by PA. The Vp (21.5 ± 11.0 mm(3) ) and Vct (21.4 ± 11.5 mm(3) ) values of 63 lesions were highly correlated (R(2) = 96.9%, P < 0.001). CONCLUSION: Cone-beam computed tomography is more accurate than PA in diagnosing periapical lesions associated with mandibular teeth. The volumes of artificial mandibular periapical lesions were accurately measured with CBCT data.