[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.

Outcome of chairside CAD/CAM ceramic restorations on endodontically treated posterior teeth: a prospective study

OBJECTIVE

The aim of this study was to evaluate the outcome and risk factors for chairside CAD/CAM full cusp coverage restorations on endodontically treated posterior teeth after 3 years of follow-up.

METHODS

A total of 245 endodontically treated posterior teeth of 224 patients were included and restored with CAD/CAM full cusp coverage all-ceramic restorations according to a standardized protocol. Patients were recalled after treatments 1 to 3 years and underwent clinical and radiological examinations. At recall, modified FDI criteria were used to determine treatment outcomes by 2 evaluators. Success was determined when FDI scores were 1-2, and failure was indicated when FDI scores were 5. Logistic regression analysis was performed to evaluate potential risk factors.

RESULTS

A total of 183 patients presented at recall, and the clinical outcomes of 201 teeth were analyzed with a recall rate of 82.0% for teeth and 81.7% for patients after 1-3 years of follow-up.185 of 201 teeth were found to have FDI scores of 1-2, and the success rate was 92%. No teeth were extracted during the follow-up period. Fourteen failed cases with an FDI score of 5 presented restoration dislocation, fracture of restoration or/and tooth. Logistic regression analysis revealed that oral parafunction (OR 2.281, 95% CI 2.2 ~ 47.5, P value 0.01) was a risk factor for success rate.

CONCLUSION

Chairside CAD/CAM all-ceramic full cusp coverage restoration was (could be) a promising alternative for restoring endodontically treated posterior teeth.

Clinical Outcome and Predictors of Endodontic Microsurgery Using Cone-beam Computed Tomography: A Retrospective Cohort Study

INTRODUCTION

The aim of this retrospective cohort study was to evaluate the clinical outcomes and identify the prognostic factors of endodontic microsurgery based on cone-beam computed tomographic (CBCT) scans.

METHODS

Patients who underwent endodontic microsurgery in teeth with asymptomatic apical periodontitis were included. The clinical outcomes were determined based on clinical and radiographic examinations after surgery 12-48 months. Radiographic healing was assessed on CBCT images by using the modified PENN 3-dimensional criteria and classified into 4 categories: complete, limited, uncertain, and unsatisfactory healing. Multivariate logistic regression was performed to detect outcome risk factors.

RESULTS

Of the 204 teeth in 173 invited patients, 148 teeth of 126 patients were examined at review. On CBCT images, 88 teeth (59.5%) showed complete healing, and 42 (28.4%) teeth showed limited healing. All these 130 teeth were asymptomatic and achieved a clinical success rate of 87.8%. Uncertain healing was observed in 9 teeth, one of which was symptomatic. The remaining 9 teeth were unsatisfactory healing on CBCT scans, including 6 teeth with clinical symptoms and 3 free. Lesion type and root-end filling quality were significant outcome predictors (P < .05). The risk of treatment failure for teeth with combined endodontic-periodontal lesions was 8.6 times higher than that for teeth with isolated endodontic lesions. Adequate root-end filling quality improved the probability of success by 5.3 times.

CONCLUSIONS

Based on CBCT data, an adequate performed endodontic microsurgery could have predictable success in teeth without periodontal involvement.

Cost-effectiveness analysis: nonsurgical root canal treatment versus single-tooth implant

BACKGROUND

Economic evaluation of nonsurgical root canal treatment (NSRCT) and single-tooth implant (STI) provides useful information for medical decision. This retrospective study aimed to evaluate the cost-effectiveness of NSRCT versus single-tooth implant (STI) after 5-year treatment in a university affiliated hospital in Beijing, China.

METHODS

211 patients who underwent NSRCT and 142 patients who had STI were included and recalled after 5-year treatment. The propensity scores were used to match the cases of two treatment modalities. At recall, outcomes were determined based on clinical and radiographical examinations. For endodontically treated cases, absence or reduction of radiolucency were defined as success. Marginal bone loss (MBL) ≤ 4 mm were determined as success for implant cases. Direct and indirect costs were calculated in China Yuan (CNY). Patients' willingness to pay (WTP) for each treatment modality was evaluated by questionnaires. A cost-effectiveness analysis was performed from the societal perspective.

RESULTS

170 patients with 120 NSRCT teeth and 96 STI were available at recall. Based on propensity score matching, 76 endodontically treated teeth were matched to 76 implants. Absence of the radiolucency was observed in 58 of 76 endodontically treated teeth (76%) and reduction of the radiolucency in 9 of 76 teeth (12%) and altogether the success rate was 88%. 100% implants were detected with marginal bone loss (MBL) ≤ 4 mm. The cost advantage of NSRCT (4,751 CNY) over STI (20,298 CNY) was more pronounced. Incremental cost effectiveness ratio (ICER) was 129,563 CNY (STI-NSRCT) per success rate gained. It exceeded the patients' willingness to pay value 7,533 CNY.

CONCLUSIONS

Clinical outcomes of NSRCT and STI could be predictable after 5-year treatment. NSRCT may be more cost-effective than STI for managing endodontically diseased teeth.

Effect of different dentin moisture on the push-out strength of bioceramic root canal sealer

Background/purpose

Different moisture condition may affect the adhesion between obturation materials and root canal walls, thus further affect the quality of root canal obturation. The aim of this study was to evaluate the influence of dentin moisture conditions after different root canal drying protocols on the push-out strength of bioceramic root canal sealer.

Materials and methods

Twenty root canals from extracted human decoronated premolars were prepared in vitro to #30/0.09 taper and assigned to 4 moisture condition groups after using different root canal drying protocols: normal moisture (paper point) group: the canals were blot dried with paper points until the last one appeared dry. Ethanol dry group: the canals were dried with paper points followed by dehydration with 95% ethanol. Isopropanol dry group: the canals were dried with paper points followed by dehydration with 70% isopropanol. Complete dry group: the canals were dried in an air-blowing thermostatic oven for at least 6 h until there was no change in weight at an interval of 1 h. After drying, the canals were obturated with bioceramic sealer iRoot SP. Then, each root was sectioned into eight slices with 1-mm-thick using a diamond saw (40 slices each group). The push-out strength was tested for each slice between the sealer and dentin wall using a universal testing machine at a crosshead speed of 0.5 mm/min, and failure modes were recorded. Two-way analysis of variance and Tukey test were used to analyze the push-out strength. Logarithmic linear regression analysis was used to compare the failure modes.

Results

Push-out strength was statistically different in different moisture groups (P < 0.05). After drying using paper point, iRoot SP specimens showed the highest push-out strength (2.04 ± 0.03 MPa), followed by 95% ethanol, 70% isopropanol. The lowest push-out strength (0.68 ± 0.04 MPa) was observed under complete dry. For the failure modes, the majority were cohesive failures in the coronal and middle thirds of the root; while in the apical third, mixed failure was common.

Conclusion

Different drying protocols influenced the push-out strength between bioceramic sealer and canal wall.

Distinctive microbiota distribution from healthy oral to post-treatment apical periodontitis

Post-treatment apical periodontitis (PoAP) occurs when root canal treatment has not adequately eliminated bacterial invasion and infection. Yet little is known about the bacterial composition and changes related to the etiology and pathogenesis of PoAP. In this study, clinical samples classified as root apex (HARD) and periapical granulation tissues (SOFT) were separately collected from 10 patients with PoAP. The microbiota of each sample was characterized by 16S rRNA gene sequencing, and the obtained dataset was coanalyzed with 20 NCBI sequence read archive (SRA) datasets of healthy oral (HO) and primary apical periodontitis (PAP). We observed 2522 operational taxonomic units (OTUs) belonging to 29 phyla, and all samples shared 86.5% of the sequence reads. The OTUs affiliated with Bacteroidetes, Firmicutes, Proteobacteria, Fusobacteria, and Actinobacteria, were identified as core microbiota, which accounted for nearly 90% of 16S rRNA sequences in all samples. However, the principal coordinates analysis (PCoA) of the beta diversity demonstrated that the three periapical statuses have distinct microbial compositions. Compared with HO and PoAP, Actinomyces has a significantly increased abundance in PAP. The microbial diversities in PoAP were significantly lower than those in the HO and PAP (p&lt;0.05). The relative abundance of most bacterial taxa was decreasing, except that Clostridia and Synergistia were increased. Furthermore, we explored the potential metabolic differences of the microbial communities by KEGG pathway prediction. We revealed that the microbiota of PoAP might have a more active metabolic capacity, including carbohydrate metabolism, energy metabolism, and enzyme cofactor/carrier biosynthesis (p&lt;0.05). Our study revealed that invasion of opportunistic pathogens such as Clostridia and Synergistia might play a significant role in PoAP, thus guiding the further study of complex microbial-host interactions and the development of more effective diagnostic and therapeutic methods.

Fracture resistance of endodontically treated teeth with cervical defects using different restorative treatments

Background/purpose

The restoration of endodontically treated teeth (ETT) with cervical defects has been a challenge for dentists. The purpose of this study was to evaluate the effect of restorative treatment on the fracture resistance of ETT with cervical defects.

Materials and methods

One hundred and twenty freshly extracted human intact straight-single-root maxillary premolars were randomly divided into 6 groups. Group 1 remained untreated. Cervical defects of 4 mm-depth and 3 mm-height were created in groups 2–6. Group 3–6: root canal treatment. Group 4: direct composite resin restoration. Group 5: 2-mm full-cusp-coverage composite resin restoration. Group 6: fiber-post-supported composite resin restoration. A static fracture test was used to determine the fracture resistance of teeth under axial (n = 10) and palatal (30°) (n = 10) loading. Fracture modes were categorized as restorable and unrestorable.

Results

Compared with intact teeth, the axial fracture resistance of teeth with cervical defects decreased by approximately 39%, and endodontic procedures resulted in 10% more reduction. When ETT with cervical defects were restored using direct composite resin filling, the axial fracture resistance recovered to 72% of that of intact teeth, but no significant change occurred under oblique loading. After full-cusp-coverage or fiber-post-supported restoration, fracture resistance showed complete recovery to the value of intact teeth (P > 0.05). Sixty percent of fractures were unrestorable for fiber-post-supported teeth, while in the full-cusp-coverage restoration group, 80–90% of fractures were restorable.

Conclusion

Full-cusp-coverage restoration or fiber-post-supported restoration could improve the fracture resistance of ETT with cervical defects, whereas unrestorable fractures easily occurred in fiber-post-supported restorations.

Physicochemical properties of a novel bioceramic silicone-based root canal sealer

Background/purpose

With introduction into endodontics, bioceramic-based sealers have gained considerable popularity for excellent properties. The aim of this study was to investigate the physicochemical properties of a novel bioceramic silicone-based sealer, GuttaFlow Bioseal, and measure heat flow of setting reactions.

Materials and methods

Film thickness, flow, working and setting time of Bioseal were compared with other 4 kinds of sealers: iRoot SP, AH Plus, RoekoSeal and GuttaFlow2. Differential scanning calorimetry test was performed to measure heat flow.

Results

Bioseal demonstrated the highest film thickness of 44 μm, double to triple that of the other 4 sealers (P < 0.05). The highest flow was detected in iRoot SP and RoekoSeal, with values of 27.35 and 27.20 mm, while GuttaFlow2 and Bioseal had the lowest of 22.31 and 21.43 mm (P < 0.05). For each sealer, working time at 37 °C was shorter than that at 23 °C (P < 0.05). At 37 °C, Bioseal had the shortest working and setting time of 4.5 and 16.3 min, while iRoot SP showed the longest of 105.0 and 571.7 min (P < 0.05). Differential scanning calorimetry test revealed that setting process of all the tested sealers was exothermic. Bioseal reached an exothermic peak at 14 min, with almost 1.5 times peak intensity of GuttaFlow2 and RoekoSeal. Whereas iRoot SP and AH Plus reached an exothermic peak 5 h after mixing, with intensity 1/2 to 2/3 that of Bioseal.

Conclusion

The novel bioceramic silicone-based sealer Bioseal showed intense and fast exothermic reactions with characteristic physicochemical properties.

Microtensile bond strength to sealer-contaminated dentin after using different cleaning protocols

Background/purpose

Sealer residues on dentin may affect bonding to restorative materials. This study aimed to evaluate the bond strength to sealer-contaminated dentin after using different cleaning protocols.

Materials and methods

Freshly extracted bovine incisors were prepared and exposed the buccal pulp chamber dentin, obtaining segments measuring 5 mm × 5 mm with a height of 3 mm. The segments were randomly distributed into 4 groups (n = 7) according to different protocols. Control group: no contamination was performed. In the three experimental groups, the segments were contaminated with epoxy resin-based sealer for 5 min, and different cleaning protocols were performed. Acetone group: acetone-saturated cotton pellets were used to wipe the sealer. Ultrasound group: ultrasonic ET-20D tip cleaning. Acetone combined with ultrasound group: cleaning with acetone-saturated cotton pellets and ultrasonic tip. All segments were bonded using a self-etch adhesive. Two samples in each group were scanned by swept-source optical coherence tomography (SS-OCT) to evaluate sealer residues. A microtensile test was performed on the remaining 5 samples, which were built up with composite resin.

Results

Sealer residues were observed in 3 of 14 (21.4%) sections of acetone group by SS-OCT. Compared to the control, ultrasound alone or in combination with acetone preserved the bond strength (P > .05). The ultrasound group exhibited the highest bond strength (39.38 MPa), which differed from that of the acetone group, which provided the lowest bond strength (32.88 MPa) (P < .05).

Conclusion

Cleaning epoxy resin-based sealer-contaminated dentin surfaces using ultrasound or combined with acetone could preserve the bond strength.

[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.

Four-year Outcome of Nonsurgical Root Canal Retreatment Using Cone-beam Computed Tomography: A Prospective Cohort Study

INTRODUCTION

The purpose of this prospective study was to investigate the 4-year outcome and prognostic factors of nonsurgical root canal retreatment determined by measuring the volumetric change of periapical radiolucencies on cone-beam computed tomographic (CBCT) scans.

METHODS

Ninety-seven endodontically treated teeth from 80 patients diagnosed as apical periodontitis and indicated for root canal retreatment were included. Retreatment was performed by 7 endodontic specialists using a standardized treatment protocol. The teeth were reexamined clinically and radiographically 48-67 months after retreatment. The volume of preoperative and postoperative periapical radiolucencies on CBCT images was independently measured by 2 examiners. Radiographic outcome is presented in 4 categories: absence, reduction, enlargement, or unchanged. Reduction or enlargement was determined when the volumetric change of radiolucency was 20% or more. Multivariate logistic regression was performed for predictor analysis.

RESULTS

Sixty-two teeth (63.9%) from 50 patients returned for follow-up. Fifty-eight teeth were included in the prognostic analysis, all of which were symptom free. The 4 remaining teeth that had been extracted because of fracture were excluded. The total volume of periapical radiolucencies at 4 years postoperatively decreased by 94.6% compared with that preoperatively (P < .001), with an average reduction of 83.4% (95% confidence interval, 69.2%-97.5%). The periapical radiolucencies were determined as absence in 44 teeth (75.9%), reduction in 10 teeth (17.2%), unchanged in 1 tooth (1.7%), and enlargement in 3 teeth (5.2%). Tooth type was identified as an outcome predictor (P < .05).

CONCLUSIONS

The 4-year outcome of endodontic retreatment is predictable, with a significant volumetric reduction in periapical radiolucencies.

Accuracy of root-end resection using a digital guide in endodontic surgery: An in vitro study

Background/Purpose

It is difficult to achieve accurate root-end resection clinically. This in vitro study was conducted to evaluate the operation accuracy of a digital endodontic surgical guide.

Materials and methods

56 extracted maxillary anterior teeth were prepared for endodontic surgical models. The models were randomly divided into 4 groups equally according to the guide (with guide/no guide) and the operator (experienced/inexperienced). Endodontic microsurgeries were performed on models in each group. The deviations in length and angle of the root-end resection were measured based on the optical scanning data of the pre- and postoperative teeth. The general linear model was performed to analyze the effect of a guide on root-end resection deviation.

Results

Using a guide, the mean length deviation for experienced/inexperienced operators reduced from 0.99 mm (95% CI [confidence interval, CI], 0.66–1.33 mm)/1.18 mm (95% CI, 0.50–1.86 mm) to 0.31 mm (95% CI, 0.20–0.42 mm)/0.31 mm (95% CI, 0.24–0.37 mm). The mean angle deviation for experienced/inexperienced operators reduced from 16.74° (95% CI, 10.61–22.86°)/15.06° (95% CI, 9.19–20.94°) to 5.04° (95% CI, 3.31–6.77°)/6.79° (95% CI, 4.91–8.67°). The difference was significant between procedures performed with and without a guide (P < 0.01).

Conclusion

Application of the digital guide in vitro endodontic surgery could improve the accuracy of root-end resection.

[Association between osteoporosis and severe periodontal attachment loss in postmenopausal women]

Objective: To investigate the association between osteoporosis and severe periodontal attachment loss in postmenopausal women. Methods: One hundred and ninety-five postmenopausal women aged 50-65 years old were included in the present study. The participant were recruited from patients in the Peking University International Hospital and through website from March, 2017 to August, 2018. Periodontal examination, filling out a structured questionnaire and bone mass density (BMD) examination were completed to each of the participants. The clinical attachment loss (CAL), oral hygiene index simplified (OHI-S), and bleeding on probing (BOP) were examined and recorded as periodontal parameters. The structured questionnaire was used to collect information of the physical activity, socioeconomic status, marital status, oral health habits, and so on. Bone mass density of the lumbar spine and left hip were scanned by using standardized dual energy X-ray absorptiometry. Based on the T-score of BMD (difference between the measured BMD and the mean value of young white women in terms of standard deviations), osteoporosis was defined as T-score≤-2.5 (according to the World Health Organization criteria). Fourteen risk factors were preliminarily screened by chi-square test, including age, duration of menopause, body mass index (BMI), exercise habit, economic status, marital status, level of education, habit of dental visit, tooth brushing habit, usage of interdental tools, OHI-S, BOP(+)%, osteoporosis in hip and osteoporosis in lumbar. Factors with P<0.05 were selected for multivariate Logistic regression analysis. Logistic regression was used to analysis the risk factors of severe periodontal attachment loss. Results: The mean age of 195 postmenopausal women was (57.8±4.3) years. After adjusting for ages, the economic status, habit of dental visit, OHI-S and BOP(+)%, there was an association of osteoporosis in hip and severe periodontal attachment loss in postmenopausal women [odds ratios (OR)=2.466, 95% confidence intervals (CI) was 1.173-5.185, P=0.017]. Conclusions: Postmenopausal women with osteoporosis in hip has a greater chance of presenting severe periodontal attachment loss.

[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．.

[Cone-beam computed tomography digital for measuring the inclination angle to the long axis of healthy maxillary anterior teeth and morphologically characterizing their labial bone plates]

OBJECTIVE

We aim to determine the thickness of the labial plate, the distance between the cement-enamel junction (CEJ) and alveolar crest, and the inclination angle of the long axis of healthy maxillary anterior teeth by using cone- beam computed tomography (CBCT).

METHODS

A total of 345 CBCT volumes obtained by Newtom VGI® CBCT were analyzed by using the NNT software. The digital measurements of the labial bone plate thickness at level 4 mm below the CEJ, the midpoint of tooth root and the radiological tooth apex, the distance between the CEJ and alveolar crest, and the angle between the long axis of the teeth and the long axis of alveolar process were obtained from the mid-sagittal planes of maxillary incisors and canines. Plate thickness 4 mm below the CEJ was measured, and values below ≥1 mm were recorded.

RESULTS

In the central incisor, 1) the angle between the long axis of the teeth and alveolar bone was 15.2°±6.2°, the distance between the CEJ and alveolar crest was (1.5±1.0) mm, labial bone plate thick-ness at 4 mm below the CEJ was (0.8±0.4) mm, the midpoint of tooth root was (0.6±0.4) mm, and the radiological tooth apex was (1.3±0.7) mm; in the lateral incisor, 16.2°±8.8°, (1.6±1.0) mm, (0.7±0.5) mm, (0.4±0.6) mm, and (1.1±0.7) mm, respectively; and in the canine, 19.0°±6.2°, (1.8±1.0) mm, (0.9±0.6) mm, (0.4±0.6) mm, and (1.2±0.7) mm, respectively. 2) The frequencies of plate thickness ≥1 mm were 28.3%, 25.8%, and 42.7% in the central incisor, lateral incisor, and canine, respectively. 3) The distance between the CEJ and alveolar crest was positively correlated with age. The correlation coefficients was 0.42 (P<0.01) in the central incisor, 0.50 (P<0.01) in the lateral incisor, and 0.62 (P<0.01) in the canine.

CONCLUSIONS

The thickness of labial bone plate is thin, the distance from CEJ to alveolar crest increases with age, and the long axis of the teeth is more inclined than the long axis of alveolar process. Knowledge of these special morphological characteristics can improve the safety and result for many dental procedures.

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.

[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.

[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.

[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.

[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.

[Circulation and etiological characterization of Salmonella enterica serotype in human in Guangdong province, 2007-2016]

Objective: To understand the circulation, drug resistance and molecular characteristics of Salmonella1, 4, [5], 12: i:- in human in Guangdong province. Methods:Salmonella1, 4, [5], 12: i:- isolated from diarrhea patients in Guangdong during 2007-2016 were detected for drug resistance, genes and PFGE characteristics. Results: A total of 2 960 strains Salmonella1, 4, [5], 12: i: - were isolated from human diarrhea cases during this period. The positive rates of the isolation increased year by year. The male to female ratio of the infection cases was 1.58∶1, and the infection mainly occurred in infants and young children. Except imipenem, Salmonella1, 4, [5], 12: i: - was resistant to other 17 antibiotics to some extent. The drug resistant rates to ceftazidime, cefotaxime and ciprofloxacin increased from 2011 to 2016. Multi-drug resistance was serious, for example, the multi-drug resistant strains with ASSuT accounted for 70.62% (435/616) and the multi-drug resistant strains with ACSuGSTTm accounted for 27.11% (167/616). The lack of fljA, fljB and hin genes, as well as the retaining of iroB, STM2740, STM2757 genes, resulted in the unable expression of FljBenx gene with 8 different defection profiles. There were 934 different PFGE patterns observed in 2 347 strains, which displayed a relatively large fingerprint polymorphism. The major PFGE pattern was JPXX01. GD0226, which was found in 97 strains, accounting for 4.13% (97/2 347). The PFGE patterns in 168 Salmonella1, 4, [5], 12: i: - strains were consistent with that of Salmonella typhimurium. Conclusions:Salmonella1,4,[5], 12: i: - strains has become the major serotype of Salmonella that cause diarrhea in human in Guangdong. The multi-drug resistance of Salmonella1,4, [5], 12: i: - was serious, and since the defection of fljA, fljB and hin genes, the expression of FljBenx protein failed. The PFGE results were diverse, which displayed polymorphism in inheritance.

[Etiologic characteristics of Shigella sonnei strains isolated from some areas of Guangdong province and Guangxi Zhuang Autonomous Region of China, 2014-2016]

Objective: To investigated the etiologic characteristics of Shigella (S.) sonnei strains causing outbreaks and sporadic cases in some areas of Guangdong province and Guangxi Zhuang Autonomous Region during 2014-2016. Methods: Fourteen S. sonnei strains isolated from outbreaks and 6 S. sonnei strains from sporadic cases from Guangdong and Liuzhou of Guangxi Zhuang Autonomous Region were tested for antimicrobial resistance and analyzed by pulsed-field gel electrophoresis (PFGE). Six typical strains were selected for whole genome sequencing typing and compared with 51 strains isolated both at home and abroad from NCBI genome database. Results: The antibiotic resistance test indicated the isolates had high resistance rate to ampicillin, tetracycline, gentamicin, trimethoprim/sulfamethoxazole and nalidixic acid, while sensitive to azithromycin, chloromycetin and imipenem. PFGE showed high similarity (93.2%) among the strains isolated from different areas. The whole genome sequencing analysis also revealed that all the typical strains were clustered into a same evolution branch, close to some strains from Korea. Conclusions: The S. sonnei strains isolated from some areas of Guangdong and Guangxi Zhuang Autonomous Region showed high resistance to commonly used antibiotics, but they were sensitive to azithromycin, chloramphenicol and imipenem. The isolates in this study also showed similar PFGE patterns and close phylogenic evolution.

[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.

[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.

[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.

[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.

[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.

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.

The association between complete absence of post-treatment periapical lesion and quality of root canal filling

AIM

The technical quality of a root canal treatment is clinically judged by the apical extension and homogeneity of the filling material imaged by periapical radiographs (PA). The aim of this experiment was to evaluate the association between the technical quality of the root canal filling and treatment outcome.

MATERIALS AND METHODS

In 234 teeth (268 roots) that underwent root-canal treatment, the quality of the root canal filling as well as the outcome of the treatment were assessed with both PA and cone-beam computed tomography (CBCT) 2 years after treatment. Satisfactory root filling on PA was defined as 0-2 mm within the radiographic apex without voids; on CBCT scans, the apical end of the canal replaced the radiographic apex. The outcome predictors were analyzed using multivariate logistic regression.

RESULTS

At recall, periapical radiolucent areas were absent in 198 (74%) roots on PA and 164 (61%) roots on CBCT scans. The presence of preoperative periapical radiolucency and the quality of root filling and coronal restoration were identified by both PA and CBCT as outcome predictors (p < 0.01). Complete absence of post-treatment periapical radiolucency was observed in CBCT scans in 81% and 49% of satisfactory and unsatisfactory root fillings, respectively, as compared to 87% and 61% revealed by PA.

CONCLUSION

Satisfactory root fillings were associated with a favorable outcome, confirmed by both PA and CBCT.

CLINICAL RELEVANCE

The outcome of root canal treatment is improved once the filling is 0-2 mm from the apex, and no voids could be detected. Technical skills and performance of root canal filling procedures should be emphasized, and suitable methods should be developed in order to achieve more compacted filling materials without voids and at the correct length.

[Clinical effects of calcium hydroxide-based sealer on chronic apical periodontitis]

OBJECTIVE

To evaluate the results of calcium hydroxide-based sealer Sealapex in the treatment of chronic apical periodontitis.

METHODS

A total of 100 cases with chronic apical periodontitis were included and divided into two groups, calcium hydroxide sealer (Sealapex) group and ZOE sealer group, and Sealapex and ZOE sealer were respectively used. All cases were followed up for two years after treatment and the clinical results compared between the two groups. The evaluation was based on clinical examination and radiographic assessment using periapical index (PAI) and digital subtraction radiography (DSR) technique.

RESULTS

There was no significant difference between the ZOE group and Sealapex group in overall healing rates and mean quantitative analysis at 3 months and 2 years after treatment (P = 0.206, 0.776). A correlation was found between PAI and DSR (P < 0.01, gamma = 0.58).

CONCLUSIONS

Sealapex sealer could obtain satisfactory effects for the treatment of chronic apical periodontitis. The combination of DSR and PAI methods was able to monitor the radiographic bone changes of periapical disease.

Systemic lupus erythematosus: a genetic epidemiology study of 695 patients from China

Our purpose was to explore potential genetic models for systemic lupus erythematosus (SLE) and analyze genetic epidemiologic characteristics of SLE in a Chinese population. Data for 695 patients with SLE were obtained by using a uniform questionnaire. Patients, clinical characteristics and their family history were analyzed using software. A complex segregation analysis was conducted to propose potential genetic models for SLE. The mean +/- SD age of onset were 30.2 +/- 10.5 years and mean time to progression to SLE was 32.5 +/- 44.4 months. The most frequent initial manifestations were malar rash (61.3%). During the evolution of the disease, the main clinical features were arthritis in 73.6% of our patients, followed by malar rash (68.1%), and renal involvement (56.7%). As the first symptom, the late-onset group (onset of disease beyond the age of 50 years) less often showed malar rash (45% vs. 63.4% in the early-onset group; p = 0.001). There were no significant differences in the other cumulative clinical symptoms between late-onset and early-onset group, except for a lower prevalence of malar rash, photosensitivity and alopecia and a higher prevalence of mucosal ulcers in the late-onset group. A positive family history of SLE was obtained in 50 patients (7.2%). There were no statistical differences in clinical characteristics between familial SLE and sporadic SLE patients. The heritability of SLE was 43.6%, the genetic model of SLE could be polygenetic model and major gene mode is the best fitted one. SLE could be a multifactorial disease with polygenetic model.

ONIOM DFT/PM3 calculations on the interaction between dapivirine and HIV-1 reverse transcriptase, a theoretical study

Theoretical investigations of the interaction between dapivirine and the HIV-1 RT binding site have been performed by the ONIOM2 (B3LYP/6-31G (d,p): PM3) and B3LYP/6-31G (d,p) methods. The results derived from this study indicate that this inhibitor dapivirine forms two hydrogen bonds with Lys101 and exhibits strong π-π stacking or H…π interaction with Tyr181 and Tyr188. These interactions play a vital role in stabilizing the NNIBP/dapivirine complex. Additionally, the predicted binding energy of the BBF optimized structure for this complex system is -18.20 kcal/mol.

MHC haplotypic association in Chinese Han patients with vitiligo

BACKGROUND

Serological typing of the human leucocyte antigen (HLA) has shown discrepancies in HLA associations with vitiligo in different ethnic populations.

OBJECTIVE

To evaluate the distributions of HLA at class I and II loci that may contribute to the genetic susceptibility of vitiligo patients in Chinese Hans population.

METHODS

We analysed the allelic frequencies of HLA class I and II by using the polymerase chain reaction sequence-specific primer (PCR-SSP) method in 187 patients with vitiligo and 273 controls in Chinese Hans. The linkage disequilibrium was calculated from a 2 x 2 table.

RESULTS

Two-locus haplotypes including HLA-A25-B13, HLA-A25-B27, HLA-A25-Cw*0602, HLA-A25-DQA1*0302, HLA-A25-DQA1*0601, HLA-A25-DQB1*0303, HLA-B13-Cw*0602, HLA-B13-DQA1*0302, HLA-B13-DQA1*0601, HLA-B27-Cw*0602, HLA-B27-DQA1*0302, HLA-B27-DQA1*0601, HLA-B27-DQB1*0303, HLA-B27-DQB1*0503, HLA-Cw*0602-DQA1*0302, HLA-Cw*0602-DQA1*0601, HLA-Cw*0602-DQB1*0303, HLA-Cw*0602-DQB1*0503 and HLA-DQA1*0302-DQB1*0503 were associated with all types of vitiligo in Chinese Hans. The extended haplotypes HLA-A25-B13-Cw*0602, HLA-A25-B27-Cw*0602, HLA-DQA1*0302-DQB1*0303-Cw*0602 and HLA-B13-DQB1*0303-Cw*0602 were found to be associated with all types of vitiligo in Chinese Hans, whereas the frequency of HLA-A25-Cw*0602-DQA1*0302 was significantly increased in generalized vitiligo but not in localized vitiligo. The frequencies of HLA-A25-DQA1*0302-DQB1*0503 and HLA-A30-DQA1*0302-DQB1*0303 were higher in childhood vitiligo than in adult vitiligo, and the frequency of HLA-A25-B13-DQB1*0303-Cw*0602 was shown to be associated with adult vitiligo but not childhood vitiligo.

CONCLUSION

This study demonstrates not only the differential association between HLA markers and types of vitiligo according to distribution or age at onset but also newly found high-risk haplotypes in Chinese vitiligo patients.