A comparison of accuracy among different approaches of static-guided implant placement in patients treated with mandibular reconstruction: A retrospective study.

OBJECTIVE: This study aimed to evaluate the differences in the accuracy of immediate intraoral, immediate extraoral, and delayed dental implant placement with surgical guides (static computer-aided implant surgery) in patients treated with mandibular reconstruction. METHODS: This was a retrospective study. The patients were divided into three groups: immediate intraoral placement (IIO), immediate extraoral placement (IEO), and delayed placement (DEL). Four variables were used to compare the planned and actual implant positions: angular deviation, three-dimensional (3D) deviation at the entry point of the implant, 3D deviation at the apical point of the implant, and depth deviation. RESULTS: The angular deviation was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .05) groups. The 3D deviation at the entry point was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .01) groups. The 3D deviation at the apical point was significantly higher in the IIO group than in the IEO (p < .01) and DEL (p < .01) groups. The depth deviation was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .05) groups. There was no statistical difference between the IEO and DEL group in angular and 3D deviation. CONCLUSION: With surgical guides, among the different approaches for implant placement, delayed implant placement remains the most accurate approach for patients treated with mandibular reconstruction.

Effectiveness of a flipped classroom for undergraduate in implant dentistry hands-on course.

PURPOSE: The purpose of this study was to compare the learning in the implant dentistry hands-on course to that of the flipped classroom (FC) and the traditional lecture cohorts (control). MATERIALS AND METHODS: In this study,80 students were enrolled for the first time in an implant dentistry program. Subsequently, they were divided into two groups. The first, the FC group, which had free access to a video with a PowerPoint presentation on the Chaoxing-WHU-MOOC platform about the implant placement on first molar sites before class. The second, the control group, which attended a didactic lecture describing implant practice on the first molar site via a bidirectional multimedia interactive teaching demonstration and then operated on a simulation model. Cone beam computed tomography (CBCT) and the deviation gauge were utilized to analyze the accuracy of the implant placement in the students' models. An online satisfaction questionnaire was distributed to both groups one week after the class. RESULTS: The linear deviation of the CBCT examination did not show any statistical difference between the two groups concerning cervical, apex, and angular. A significant buccal deviation was observed in the control group compared with the FC group (mean: 0.7436 mm vs. 0.2875 mm, p = 0.0035), according to the restoration-level deviation gauge. A total of 74.36% of students in the FC group placed implant within 0.5 mm buccal-to-lingual deviations, but only 41.03% of students in the control group reached within 0.5 mm buccal-to-lingual deviation ranges. Additionally, 91.67% of the students in the FC group and 97.5% of the students in the control group were satisfied with the practical implant class. CONCLUSION: FC was more effective than a didactic lecture for implant dentistry practical skill acquisition.

Silver Nanoparticle-Anchored Human Hair Kerateine/PEO/PVA Nanofibers for Antibacterial Application and Cell Proliferation.

The main core of wound treatment is cell growth and anti-infection. To accelerate the proliferation of fibroblasts in the wound and prevent wound infections, various strategies have been tried. It remains a challenge to obtain good cell proliferation and antibacterial effects. Here, human hair kerateine (HHK)/poly(ethylene oxide) (PEO)/poly(vinyl alcohol) (PVA) nanofibers were prepared using cysteine-rich HHK, and then, silver nanoparticles (AgNPs) were in situ anchored in the sulfur-containing amino acid residues of HHK. After the ultrasonic degradation test, HHK/PEO/PVA nanofibrous mats treated with 0.005-M silver nitrate were selected due to their relatively complete structures. It was observed by TEM-EDS that the sulfur-containing amino acids in HHK were the main anchor points of AgNPs. The results of FTIR, XRD and the thermal analysis suggested that the hydrogen bonds between PEO and PVA were broken by HHK and, further, by AgNPs. AgNPs could act as a catalyst to promote the thermal degradation reaction of PVA, PEO and HHK, which was beneficial for silver recycling and medical waste treatment. The antibacterial properties of AgNP-HHK/PEO/PVA nanofibers were examined by the disk diffusion method, and it was observed that they had potential antibacterial capability against Gram-positive bacteria, Gram-negative bacteria and fungi. In addition, HHK in the nanofibrous mats significantly improved the cell proliferation of NIH3T3 cells. These results illustrated that the AgNP-HHK/PEO/PVA nanofibrous mats exhibited excellent antibacterial activity and the ability to promote the proliferation of fibroblasts, reaching our target applications.

Supramolecular Gel Based on Crown-Ether-Appended Dynamic Covalent Macrocycles.

A new type of dynamic covalent macrocycle with self-promoted supramolecular gelation behavior is developed. Under oxidative conditions, the dithiol compound containing a diamide alkyl linker with an odd number (7) of carbon chain and an appended crown ether shows a remarkable gelation ability in acetonitrile, without any template molecules. Due to the existence of crown ethers and disulfide bonds, the obtained gel shows a multiple stimuli-responsiveness behavior. The mechanical properties and reversibility of the gel are investigated. Computational modeling suggests that the peripheral chain for diamide hydrogen bonding is responsible for the gelation process.

[Ectopic osteogenesis of stromal cell-derived factor 1 combined with simvastatin-loaded collagen scaffold in vivo].

OBJECTIVE: To construct and evaluate a novel tissue-engineered bone composed of murine stromal cell-derived factor 1(mSDF-1), simvastatin (SIM) and collagen scaffold (Bio-Oss®), serving as a cell-homing approach for bone formation. METHODS: In the study, 32 ICR mice were randomly divided into 4 groups,each group including 8 mice. The drug-loaded collagen scaffolds were implanted subcutaneously onto the cranium of each mouse according to the groups: (1) 1:50 (volume ratio) dimethyl sulfoxide (DMSO)/phosphate-buffered saline (PBS) solution + collagen scaffold (blank control group); (2) 10⁻³ mol/L SIM solution + collagen scaffold (SIM group); (3) 200 mg/L mSDF-1 solution + collagen scaffold (mSDF-1 group); and (4) 10® mol/L SIM +200 mg/L mSDF-1 solution + collagen scaffold (SIM + mSDF-1 group). One week after implantation, the mice were treated by injecting the same drug solution mentioned above around the scaffold once a day for two days. The specimens were harvested 6 weeks after implantation and the bone formation was evaluated by soft X-ray analysis, HE staining and immunohistochemical staining. Angiogenesis of each group was checked by calculation of vessels in each tissue section. RESULTS: Six weeks after implantation, the collagen scaffolds were retrieved. The value of gray scale for the SIM+mSDF-1 group [(421 836.5 ± 65 425.7)pixels] was significantly higher than that of the blank control group[(153 345.6 ± 45 222.2) pixels, P<0.01], the SIM group [(158 119.2 ± 100 284.2)pixels, P<0.01], and the mSDF-1 group[(255 529.5 ± 152 142.4)pixels, P<0.05]; HE staining analysis revealed that significant bone formation was achieved in the SIM + mSDF-1 group; The immunohistochemical staining showed the existence of osteopontin and osteocalcin in the SIM + mSDF-1 group; There were more vessels in the SIM+mSDF-1 group[(46 ± 8)vessels/mm²] than in the blank control group [(23 ± 7) vessels/mm2, P<0.01], and the SIM group[(24 ± 6) vessels/mm2, P<0.01]. CONCLUSION: The novel tissue-engineered bone composed of mSDF-1, SIM and collagen scaffolds has the potential to form bone subcutaneously in vivo. It represents a novel method of in vivo bone re-generation without seed cell delivery.

One-stage jaw reconstruction and prosthetic rehabilitation with an iliac flap: a case report and literature review.

BACKGROUND: One-stage jaw reconstruction with fibular flap and prosthetic rehabilitation restores bony and dental continuity simultaneously. It was also called as "jaw-in-a-day (JIAD)" technique. However, bone volume and height of fibular flap may be insufficient for dental implant insertion. The provision of a considerable amount of bone makes an iliac flap the ideal choice in these cases. We present the first case report to document the use of one-stage jaw reconstruction and prosthetic rehabilitation with the iliac flap. CASE PRESENTATION: We modified the conventional JIAD workflow to make it suitable for iliac flap. Two cases were presented who both underwent segmental mandibulectomy for ameloblastoma. Virtual surgical planning was performed in all cases. The iliac crest was positioned upward to provide cortical bone for achieving primary stability of dental implants. Similar to the "all-on-4" procedure, the iliac bone was placed 12 to 15 mm below the occlusal plane to create adequate space for the implant-retained prosthesis. Immediate implant-based dental rehabilitation was performed at same stage. The surgery was successful in all cases without any short-term complications. In the first postoperative week, patients were given a liquid diet through a nasal feeding tube. The liquid diet is advised until 1 month after the surgery. Thereafter, a soft diet is recommended. Patients were advised to resume routine mastication and normal diet 3 months after the surgery. Peri-implantitis occurred in one patient, and additional gingival graft was required. Postoperative function and esthetics were satisfactory at the last follow-up visit. CONCLUSIONS: One-stage jaw reconstruction and prosthetic rehabilitation with the iliac flap are safe and useful for restoring postoperative function and esthetics. It should be used in more cases with a longer follow-up in further studies.

[Preparation and in vitro evaluation of doxorubicin-loaded magnetic iron oxide nanoparticles].

PEG-modified magnetic Fe3O4 (Fe3O4-PEG) nanoparticles were sythesized using a solvothermal reaction and characterized with transmission electron microscopy (TEM) and thermo gravimetric analysis (TGA). The photothermal effect and photothermal destruction of cancer cells were evaluated. Then the doxorubicin loaded Fe3O4-PEG (DOX-Fe3O4-PEG) nanoparticles were prepared. The cytotoxicity and combined chemotherapy/photothermal therapy (PTT) effect were investigated. Uniform PEG coated Fe3O4 nanoparticles with particle size of 155 nm were obtained in the experiment. The loading and release of doxorubicin on Fe3O4-PEG were pH-dependent. The drug loading capacity in water was 21%. The results of MTT indicated a good biocompatiblity of Fe3O4-PEG nanoparticles and high cytotoxicity of DOX-Fe3O4-PEG. In combined therapy experiment, photothermal therapy demonstrated unambiguously enhanced chemotherapy efficacy. In conclusion, the obtained Fe3O4-PEG nanoparticles which exhibit good photothermal effect and drug loading capacity can be used for chemotherapy and photothermal therapy. The synergetic anti-tumor activity indicates the potential for the combined application of chemotherapy and photothermal therapy in cancer treatment.

Genomic insights into the genetic basis of eagle-beak jaw, large head, and long tail in the big-headed turtle.

The big-headed turtle (Platysternon megacephalum) is an endemic chelonian species in Asia. Unlike most other turtles in the world, P. megacephalum is characterized with eagle-beak jaw, large head, and long tail. Although these unique characteristics are well recognized, the underlying genetic basis remains largely elusive. Here, we performed comparative genomic analysis between P. megacephalum and other representative species, aiming to reveal the genetic basis of the unique morphological features. Our results revealed that the eagle-beak jaw is most likely enabled by combined effects of expansion of SFRP5, extraction of FGF11, and mutation of both ZFYVE16 and PAX6. Large head is supported by mutations of SETD2 and FGRF2 and copy number variations of six head circumference modulation-related genes (TGFBR2, Twist2, Rdh10, Gas1, Chst11, and SNAP25). The long tail is probably involved in a genetic network comprising Gdf11, Lin 28, and HoxC12, two of which showed a consistent expression pattern with a model organism (mice). These findings suggest that expansion, extraction, and mutation of those genes may have profound effects on unique phenotypes of P. megacephalum.

Water-fueled autocatalytic bactericidal pathway based on e-Fenton-like reactions triggered by galvanic corrosion and extracellular electron transfer.

Water is generally considered to be an undesirable substance in fuel system, which may lead to microbial contamination. The antibacterial strategies that can turn water into things of value with high disinfection efficacy have been urgently needed for fuel system. Here, we reveal a water-fueled autocatalytic bactericidal pathway comprised by bi-metal micro-electrode system, which can spontaneously produce reactive oxygen species (mainly H2O2 and O2•-) by the electron Fenton-like reaction in water medium without external energy., The respiratory chain component of bacteria and the galvanic corrosion on the coated metals were two electron sources in the system. The specific model of Ag-Ru water-fueled autocatalytic (WFA) microelectrode particles presents extremely high disinfection efficiency (>99.9999%) in less than one hour for three aerobic bacteria (Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis) in LB media and high disinfection efficiency for the anaerobic bacteria (Desulfovibrio alaskensis) in Postgate E media without natural light irradiation. Overall, the novel WFA Ag-Ru antibacterial material explored in this study has a high potential for sterilizing applications in fuel system and this work provides the potential for the development of non-chemical and water-based antibacterial materials, such as WFA Ag-Ru antibacterial coating on stainless steel.

Proliposomes for oral delivery of dehydrosilymarin: preparation and evaluation in vitro and in vivo.

AIM: To formulate proliposomes with a polyphase dispersed system composed of soybean phospholipids, cholesterol, isopropyl myristate and sodium cholate to improve the oral bioavailability of dehydrosilymarin, an oxidized form of herbal drug silymarin. METHODS: Dehydrosilymarin was synthesized from air oxidation of silymarin in the presence of pyridine, and proliposomes were prepared by a film dispersion-freeze drying method. Morphological characterization of proliposomes was observed using a transmission electron microscope. Particle size and encapsulation efficiency of proliposomes were measured. The in vitro release of dehydrosilymarin from suspension and proliposomes was evaluated. The oral bioavailability of dehydrosilymarin suspension and proliposomes was investigated in rabbits. RESULTS: The proliposomes prepared under the optimum conditions were spherical and smooth with a mean particle size in the range of 7 to 50 nm. Encapsulation efficiency was 81.59%±0.24%. The in vitro accumulative release percent of dehydrosilymarinloaded proliposomes was stable, which was slow in pH 1.2, and increased continuously in pH 6.8, and finally reached 86.41% at 12 h. After oral administration in rabbits, the relative bioavailability of proliposomes versus suspension in rabbits was 228.85%. CONCLUSION: Proliposomes may be a useful vehicle for oral delivery of dehydrosilymarin, a drug poorly soluble in water.

Microplastics aggravate the joint toxicity to earthworm Eisenia fetida with cadmium by altering its availability.

Microplastics (MPs) have become a global environmental issue, however, the threats of metal-associated MPs to soil ecosystems and their involved processes have not been fully disclosed. In this study, a microcosm experiment with co-exposure of polyethylene and cadmium was conducted to determine their joint effects on the earthworm Eisenia fetida and to explore their relationship with the soil Cd availability that affected by MPs. The results showed that 28-day co-exposure of MPs and Cd significantly induced higher avoidance responses, weight loss and reduced reproduction of earthworms with the increasing content of pollutants. MPs and Cd jointly inhibited the superoxide enzyme (SOD) and peroxidase (POD) activities while increasing the glutathione (GSH) and malondialdehyde (MDA) activities in E. fetida. Histopathological changes and DNA damage to earthworm sperm also occurred in an MPs-dose-dependent manner. In addition, the presence of MPs significantly increased the soil diethylenetriaminepentaacetic acid (DTPA)-Cd concentrations by 1.20-fold and 1.43-fold while increasing the Cd bioaccumulation in E. fetida by 2.65-fold and 1.42-fold in low- and high-Cd-contaminated soil, respectively, which potentially contributed to the aggravation of the joint toxicity to E. fetida. In conclusion, this study demonstrated that microplastics could enhance the cadmium availability in the co-exposure soil which resulted in the joint toxicity of metal-associated MPs to soil organisms. CAPSULE: MPs increased soil Cd availability and potentially aggravated the joint toxicity with Cd to Eisenia fetida.

[Correlation between the phenotype and genotype of tooth agenesis patients by tooth agenesis code].

OBJECTIVE: To analyze the correlation between the phenotype and genotype of tooth agenesis using the tooth agenesis code (TAC) and the traditional descriptor for missing teeth. METHODS: Patients with isolated hypodontia caused by PAX9 or MSX1 mutation reported before May 2007 were enrolled. The teeth missing rate and TAC code were recorded. The missing teeth patterns caused by the two mutations were compared. RESULTS: The teeth missing rates in each teeth positions were significantly different between maxillary and mandibular except maxillary central incisor, lateral incisor and mandibular canine, first molar (P<0.05, P<0.001). MSX1 gene mutation often led to the loss of maxillary first premolar, maxillary second premolar, and mandibular second premolar, while PAX9 gene mutation often led to the loss of the first, second, and third molars. The results were similar when analyzed either by TAC code analysis or by traditional descriptor. CONCLUSIONS: PAX9 and MSX1 gene mutation can cause different phenotypes of tooth agenesis. The TAC code can be used in the analysis of the correlation between phenotype and genotype of the missing teeth patients.

Occlusal Rehabilitation in a Patient with Oligodontia and Microdontia using Implants and Full-Ceramic Restorations: A Clinical Report.

Oligodontia is the agenesis of six or more permanent teeth, excluding the third molars. Multidisciplinary dental treatments should be performed sequentially due to the restoration requirements for good oral function, aesthetics and self-confidence of patients. In this study, we report a case using dental implants and full-ceramic prostheses to restore the absent and malformed teeth in a patient with agenesis of 18 permanent teeth and with some primary teeth retained. The dental sequential treatments began when she was 16 years old, and she wore removable partial dentures for 4 years with unsatisfying restoration outcome. When she became an adult, dental implants and full-ceramic prostheses were used to restore the absent and malformed teeth. Finally, the patient was very satisfied with the functional and aesthetic outcomes of the prosthetic treatment.

Combined magnetic porous molecularly imprinted polymers and deep eutectic solvents for efficient and selective extraction of aristolochic acid I and II from rat urine.

Aristolochia and related plants contain nephrotoxins and mutagens in the form of aristolochic acids (AAs). However, there is still lack of a fast and specific method for monitoring AAs in biological samples. Herein, we synthesized a hybrid magnetic mesoporous carbon-molecularly imprinted polymers (MMC@MIPs) as a novel magnetic solid-phase extraction (MSPE) adsorbent for selective recognition of aristolochic acid I and II from rat urine samples. The choline chloride/glycol-based deep eutectic solvent (DES) and indomethacin were used as the eluent and dummy template molecule accordingly. The morphology, structure property and surface groups of the prepared materials were investigated in sequence, and the optimum conditions of the MMC@MIPs-MSPE procedure were also optimized well. Results showed that the proposed method had a relatively satisfactory recovery (86.7-94.3%), with low standard deviation (<4.85%) and acceptable correlation coefficients (0.991-0.996). Overall, this work not only provides an inexpensive and eco-friendly method to fabricate MMC@MIPs, but also develops a highly promising approach for the detection of aristolochic acid I and II in biological samples.

Oral health and dental status in people with epilepsy in rural China.

PURPOSE: We evaluated the oral health and dental status of people with epilepsy, and their relationship to seizure frequency, in a community cohort in rural China. METHODS: A cross-sectional study of people with epilepsy was carried out in areas in Henan, Shanxi and Ningxia provinces of China. All participants underwent a specially designed "Oral health and Dental status Questionnaire". Univariate and multivariate analyses were used to explore the relationships between seizure frequency and oral health and dental status. RESULTS: A total of 875 people participated. Almost two thirds (65.8%) reported brushing their teeth at least once a day but 634 (73.0%) brushed their teeth for less than 3 min each time. Only 80 (9.1%) had visited a dental clinic in the previous year. Multivariate logistic regression analysis showed that having 1-4 seizures/month (OR 0.60, 95%CI 0.40-0.90) or >4 seizures/month (OR 0.38, 95%CI 0.22-0.66) was associated with decreased odds of brushing teeth at least once a day, and higher seizure frequency was associated with increased odds of dental injury due to seizures (OR 2.07, 95%CI 1.22-3.50 for <1 seizure/month; OR 2.12, 95%CI 1.25-3.58 for 1-4 seizures/month; OR 3.09, 95%CI 1.57-6.07 for >4 seizures/month). CONCLUSION: Seizure frequency was significantly associated with seizure-related dental injury, and with the lack of good oral health practice. Improvement in the oral health of people with epilepsy in resource-poor areas should be encouraged.

[Clinical analysis of children with severe hand-foot-and-mouth disease in Shanghai].

OBJECTIVE: To retrospectively analyzed the clinical features and epidemiology of children with severe hand-foot-and-mouth disease during 2009 and 2010 in Shanghai to investigate some risk factors with fatal cases. METHOD: All the clinical records and laboratory results of serious patients were collected. A retrospective study was performed. RESULT: A total of 748 serious patients were enrolled into this study, and the ratio of male to female was about 1.7:1; 724 patients were categorized into stage 2 with 254 patients in 2009 and 470 in 2010; 24 patients were categorized into stage 3 with 17 in 2009 and 7 in 2010. The rate of severity in 2010 (1.5%) was lower than in 2009 (6.3%) (χ2=12.836, P<0.01). Seven patients of stage 3 died, with the fatality 29.2%, which was higher than in stage 2 (P<0.01). The children aged between 3 months 10 days to 12 years 9 months with onset median age of 25 months. Among them, 77.1% patients aged between 1 and 4 years which also accounted for 79.2% of the fatal cases (19/24). But there was no significant difference between the age and the severity (χ2=0.804, P>0.05). Fever (100%), vomiting (57.0%) and myoclonus jerk (62.3%) were the most frequent symptoms occurred in those serious cases. The average period of fever in children of stage 2 and 3 was (4.10±1.40) d and (5.05±1.05) d, respectively, which indicated significant difference between the two groups (t=3.173, P<0.05). The average values of white-blood-cell counts and blood glucose in fatal patients were (14.8±6.25)×10(9)/L and (8.63±3.51) mmol/L. They were higher when compared to those in stage 2 with the white-blood-cell counts of (11.8±4.23)×10(9)/L and blood glucose of (5.51±2.14) mmol/L (P<0.05). But there was no significant difference in C-reactive protein or cerebrospinal fluid white-blood-cell counts; A total of 182 patients were enrolled for MRI study during the acute stage with 37 (37/182, 20.3%) presented abnormal findings. Among them, most frequent findings were hyperintense lesions seen in brain stem (11 cases). A stage 3 case who died presented brain edema on MRI examination. CONCLUSION: The epidemic of HFMD has some correlation with the area, season, health condition of the family and gender of the children. Children under 4 years of age especially those who lived in rural areas were susceptible to the HFMD. Frequent vomiting or myoclonus jerk may indicate the central nervous system involvement. But persistent high fever may indicate tendency to deteriorate. Some laboratory examinations can help find the fatal cases at an early time.

[The experimental study of the relationship between preparation height and retention of complete crowns].

PURPOSE: This study was to discuss the influence of preparation height on retention of complete crown. METHODS: In this study we measured the retention of complete crown with the preparation height 2 mm, 3 mm, 4 mm and 5 mm. All crowns had no preparation taper and no bonding agent was used. The retention of crowns was measured and the data was statistically analyzed by t test. RESULTS: The preparation height was directly proportional to the retention of complete crown. And the crown with the height of 2 mm had enough retention when the crown had no preparation taper. CONCLUSION: In order to get enough retention of short height molar, we should induce the preparation taper.