Polysaccharide-Based Coating with Excellent Antibiofilm and Repeatable Antifouling-Bactericidal Properties for Treating Infected Hernia.

In recent years, the utilization of medical devices has gradually increased and implantation procedures have become common treatments. However, patients are susceptible to the risk of implant infections. This study utilized chemical grafting to immobilize polyethylenimine (QPEI) and hyaluronic acid (HA) on the surface of the mesh to improve biocompatibility while being able to achieve antifouling antimicrobial effects. From the in vitro testing, PP-PDA-Q-HA exhibited a high antibacterial ratio of 93% against S. aureus, 93% against E. coli, and 85% against C. albicans. In addition, after five rounds of antimicrobial testing, the coating continued to exhibit excellent antimicrobial properties; PP-PDA-Q-HA also inhibits the formation of bacterial biofilms. In addition, PP-PDA-Q-HA has good hemocompatibility and cytocompatibility. In vivo studies in animal implantation infection models also demonstrated the excellent antimicrobial properties of PP-PDA-Q-HA. Our study provides a promising strategy for the development of antimicrobial surface medical materials with excellent biocompatibility.

Observation of Electronic Nematicity Driven by the Three-Dimensional Charge Density Wave in Kagome Lattice KV3Sb5.

Kagome superconductors AV3Sb5 (A = K, Rb, Cs) provide a fertile playground for studying intriguing phenomena, including nontrivial band topology, superconductivity, giant anomalous Hall effect, and charge density wave (CDW). Recently, a C2 symmetric nematic phase prior to the superconducting state in AV3Sb5 drew enormous attention due to its potential inheritance of the symmetry of the unusual superconductivity. However, direct evidence of the rotation symmetry breaking of the electronic structure in the CDW state from the reciprocal space is still rare, and the underlying mechanism remains ambiguous. The observation shows unconventional unidirectionality, indicative of rotation symmetry breaking from six-fold to two-fold. The interlayer coupling between adjacent planes with π-phase offset in the 2 × 2 × 2 CDW phase leads to the preferred two-fold symmetric electronic structure. These rarely observed unidirectional back-folded bands in KV3Sb5 may provide important insights into its peculiar charge order and superconductivity.

Creating a 3D diagnostic cast with realistic tooth shade and translucency using an open source nondental CAD software program: A dental technique.

This article describes a digital technique for acquiring a 3-dimensional (3D) diagnostic cast with authentic tooth shade and translucency using an open source nondental computer-aided design (CAD) software program detailing the operational methods and parameters. The resultant 3D diagnostic cast can be transmitted to a dental laboratory for the fabrication of definitive prostheses.

[Effects of different exercise modes on neuromuscular junction and metabolism of skeletal muscle-related proteins in aging rats].

The present study aimed to explore the effects of different exercise modes on neuromuscular junction (NMJ) and metabolism of skeletal muscle-related proteins in aging rats. Ten from 38 male Sprague-Dawley (SD) rats (3-month-old) were randomly selected into young (Y) group, while the rest were raised to 21 months old and randomly divided into elderly control (O), endurance exercise (EN) and resistance exercise (R) groups. After 8 weeks of corresponding exercises training, the gastrocnemius muscles of rats were collected, and the expression of S100B in Schwann cells was detected by immunofluorescence staining. Western blot was used to detect the protein expression levels of agglutinate protein (Agrin), low-density lipoprotein receptor-related protein 4 (Lrp4), muscle- specific kinase protein (MuSK), downstream tyrosine kinase 7 (Dok7), phosphorylated protein kinase B (p-Akt), phosphorylated mammalian target rapamycin (p-mTOR), and phosphorylated forkhead box O1 (p-FoxO1) in rat gastrocnemius muscles. The results showed that, endurance and resistance exercises increased the wet weight ratio of gastrocnemius muscle in the aging rats. The protein expression of S100B in the R group was significantly higher than those in the O and EN groups. Proteins related to NMJ function, including Agrin, Lrp4, MuSK, and Dok7 were significantly decreased in the O group compared with those in the Y group. Resistance exercise up-regulated these four proteins in the aging rats, whereas endurance exercise could not reverse the protein expression levels of Lrp4, MuSK and Dok7. Regarding skeletal muscle-related proteins, the O group showed down-regulated p-Akt, and p-mTOR protein expression levels and up-regulated p-FoxO1 protein expression level, compared to the Y group. Resistance and endurance exercises reversed the changes in p-mTOR and p-FoxO1 protein expression in the aging rats. These findings demonstrate that both exercise modes can enhance NMJ function, increase protein synthesis and reduce the catabolism of skeletal muscle-related proteins in aging rats, with resistance exercise showing a more pronounced effect.

MicroRNA expression as a prognostic biomarker of tongue squamous cell carcinoma (TSCC): a systematic review and meta-analysis.

BACKGROUND: Recent studies have indicated that microRNA (miRNA) expression in tumour tissues has prognostic significance in Tongue squamous cell carcinoma (TSCC) patients. This study explored the possible prognostic value of miRNAs for TSCC based on published research. METHODS: A comprehensive literature search of multiple databases was conducted according to predefined eligibility criteria. Data were extracted from the included studies by two researchers, and HR results were determined based on Kaplan‒Meier curves according to the Tierney method. The Newcastle‒Ottawa Scale (NOS) and GRADE (Grading of Recommendations Assessment, Development, and Evaluation) pro-GDT were applied to assess the quality of all studies. Publication bias was estimated by funnel plot, Egger's rank correlation test and sensitivity analysis. RESULTS: Eleven studies (891patients) were included, of which 6 reported up-regulated miRNAs and 7 mentioned down-regulated miRNAs. The pooled hazard ratio (HR) from the prognostic indicator overall survival (OS) was 1.34 (1.25-1.44), p < 0.00001, indicating a significant difference in miRNA expression between TSCC patients with better or worse prognosis. CONCLUSION: MiRNAs may have high prognostic value and could be used as prognostic biomarkers of TSCC.

[Comparison of the virtual surgical planning position of maxilla and condyle with the postoperative real position in patients with mandibular protrusion].

OBJECTIVE: To compare the difference between virtual surgical planning (VSP) position and postoperative real position of maxilla and condyle, and to explore the degree of intraoperative realization of VSP after orthognathic surgery. METHODS: In this study, 36 patients with mandibular protrusion deformity from January 2022 to December 2022 were included. All the patients had been done bilateral sagittal split ramus osteotomy (SSRO) combined with Le Fort Ⅰ osteotomy under guidance of VSP. The VSP data (T0) and 1-week postoperative CT (T1) were collected, the 3D model of postoperative CT was established and segmented into upper and lower jaws in CCMF Plan software. At the same time, accor-ding to the morphology of palatal folds, the virtual design was registered with the postoperative model, and the unclear maxillary dentition in the postoperative model was replaced. Then the postoperative model was matched with VSP model by registration of upper skull anatomy that was not affected by the operation. The three-dimensional reference plane and coordinate system were established. Selecting anatomical landmarks and their connections of condyle and maxilla for the measurement, we compared the coordinate changes of marker points in three directions, and the angle changes between the line connecting the marker points and the reference plane to analyze the positional deviation and the angle deviation of the postoperative condyle and maxilla compared to VSP. RESULTS: The postoperative real position of the maxilla deviates from the VSP by nearly 1 mm in the horizontal and vertical directions, and the anteroposterior deviation was about 1.5 mm. In addition, most patients had a certain degree of counterclockwise rotation of the maxilla after surgery. Most of the bilateral condyle moved forward, outward and downward (the average distance deviation was 0.15 mm, 1.54 mm, 2.19 mm, respectively), and rotated forward, outward and upward (the average degree deviation was 4.32°, 1.02°, 0.86°, respectively) compared with the VSP. CONCLUSION: VSP can be mostly achieved by assistance of 3D printed occlusal plates, but there are certain deviations in the postoperative real position of maxilla and condyle compared with VSP, which may be related to the rotation axis of the mandible in the VSP. It is necessary to use patient personalized condylar rotation axis for VSP, and apply condylar positioning device to further improve surgical accuracy.

Influence of a new abutment design concept on the biomechanics of peri-implant bone, implant components, and microgap formation: a finite element analysis.

BACKGROUND: A new two-piece abutment design consisting of an upper prosthetic component and tissue-level base has been introduced; however, the biomechanical behavior of such a design has not been documented. This study aimed to investigate the effect of a two-piece abutment design on the stress in the implant components and surrounding bone, as well as its influence on microgap formation. METHODS: To simulate the implant models in the mandibular left first molar area, we established nine experimental groups that included three bone qualities (type II, III, and IV) and three implant-abutment designs (internal bone level, tissue level, and a two-piece design). After the screw was preloaded, the maximum occlusal (600 N) and masticatory (225 N) forces were established. Finite element analysis was performed to analyze the maximum and minimum principal stresses on the peri-implant bone; the von Mises stresses in the implants, abutments, bases, and screws, and the microgaps at the implant-abutment, implant-base, and base-abutment interfaces. RESULTS: For all three loading methods, the two-piece abutment design and bone-level connection exhibited similarities in the maximum and minimum principal stresses in the peri-implant bone. The von Mises stresses in both screws and bases were greater for the two-piece design than for the other connection types. The smallest microgap was detected in the tissue-level connection; the largest was observed at the implant-base interface in the two-piece design. CONCLUSIONS: The present study found no evidence that the abutment design exerts a significant effect on peri-implant bone stress. However, the mechanical effects associated with the base and screws should be noted when using a two-piece abutment design. The two-piece abutment design also had no advantage in eliminating the microgap.

Deep learning pan-specific model for interpretable MHC-I peptide binding prediction with improved attention mechanism.

Accurate prediction of peptide binding affinity to the major histocompatibility complex (MHC) proteins has the potential to design better therapeutic vaccines. Previous work has shown that pan-specific prediction algorithms can achieve better prediction performance than other approaches. However, most of the top algorithms are neural networks based black box models. Here, we propose DeepAttentionPan, an improved pan-specific model, based on convolutional neural networks and attention mechanisms for more flexible, stable and interpretable MHC-I binding prediction. With the attention mechanism, our ensemble model consisting of 20 trained networks achieves high and more stabilized prediction performance. Extensive tests on IEDB's weekly benchmark dataset show that our method achieves state-of-the-art prediction performance on 21 test allele datasets. Analysis of the peptide positional attention weights learned by our model demonstrates its capability to capture critical binding positions of the peptides, which leads to mechanistic understanding of MHC-peptide binding with high alignment with experimentally verified results. Furthermore, we show that with transfer learning, our pan model can be fine-tuned for alleles with few samples to achieve additional performance improvement. DeepAttentionPan is freely available as an open-source software at https://github.com/jjin49/DeepAttentionPan.

Emergence of New van Hove Singularities in the Charge Density Wave State of a Topological Kagome Metal RbV_{3}Sb_{5}.

Quantum materials with layered kagome structures have drawn considerable attention due to their unique lattice geometry, which gives rise to flat bands together with Dirac-like dispersions. Recently, vanadium-based materials with layered kagome structures were discovered to be topological metals, which exhibit charge density wave (CDW) properties, significant anomalous Hall effect, and unusual superconductivity at low temperatures. Here, we employ angle-resolved photoemission spectroscopy to investigate the electronic structure evolution upon the CDW transition in a vanadium-based kagome material RbV_{3}Sb_{5}. The CDW phase transition gives rise to a partial energy gap opening at the boundary of the Brillouin zone and, most importantly, the emergence of new van Hove singularities associated with large density of states, which are absent in the normal phase and might be related to the superconductivity observed at lower temperatures. Our work sheds light on the microscopic mechanisms for the formation of the CDW and superconducting states in these topological kagome metals.

Prosthodontic Rehabilitation of a Patient with Hypophosphatasia Using Dental Implants: A Case Report with Seven Years Follow-Up.

Hypophosphatasia is a rare metabolic inherited dento-osseous disorder. Although there is some available literature on various dental characteristics of hypophosphatasia patients, few reports focus on the effects of hypophosphatasia on the permanent dentition and prosthodontic rehabilitation, particularly in relation to the use of dental implants. This paper reports a case with hypophosphatasia and prosthodontic rehabilitation using dental implants with 7-year follow-up.

Coexistence of Ferromagnetic and Stripe Antiferromagnetic Spin Fluctuations in SrCo_{2}As_{2}.

We use inelastic neutron scattering to study energy and wave vector dependence of spin fluctuations in SrCo_{2}As_{2}, derived from SrFe_{2-x}Co_{x}As_{2} iron pnictide superconductors. Our data reveal the coexistence of antiferromagnetic (AF) and ferromagnetic (FM) spin fluctuations at wave vectors Q_{AF}=(1,0) and Q_{FM}=(0,0)/(2,0), respectively. By comparing neutron scattering results with those of dynamic mean field theory calculation and angle-resolved photoemission spectroscopy experiments, we conclude that both AF and FM spin fluctuations in SrCo_{2}As_{2} are closely associated with a flatband of the e_{g} orbitals near the Fermi level, different from the t_{2g} orbitals in superconducting SrFe_{2-x}Co_{x}As_{2}. Therefore, Co substitution in SrFe_{2-x}Co_{x}As_{2} induces a t_{2g} to e_{g} orbital switching, and is responsible for FM spin fluctuations detrimental to the singlet pairing superconductivity.

Periodontal regeneration using bone morphogenetic protein 2 incorporated biomimetic calcium phosphate in conjunction with barrier membrane: A pre-clinical study in dogs.

AIM: To evaluate the effect of bone morphogenetic protein 2 (BMP-2) incorporated biomimetic calcium phosphate (BMP-2/BioCaP) in conjunction with barrier membrane on periodontal regeneration in chronic periodontitis experimental model. MATERIAL AND METHODS: Chronic periodontitis experimental model with critical-sized supra-alveolar defects was created in 15 dogs' mandibles. After the initial periodontal therapy, the defects were randomly assigned to the following groups: (a) control; (b) barrier membrane; (c) deproteinized bovine bone mineral + barrier membrane; (d) BioCaP + barrier membrane and (e) BMP-2/BioCaP + barrier membrane (6 quadrants with 18 teeth per group). Eight weeks later, clinical examinations, micro-CT, and histomorphometric analyses were performed. RESULTS: Clinical examinations, including plaque index, bleeding index, and probing depth, were similar for all groups. In contrast, the clinical attachment loss was significantly lower in defects grafted with BMP-2/BioCaP and barrier membrane. The micro-CT results showed that the height of mineralized tissue in defects grafted with BMP-2/BioCaP and barrier membrane was significantly higher. For histometric analysis, the defects grafted with BMP-2/BioCaP and barrier membrane exhibited significantly more connective tissue height, new cementum height, new bone height and area, as well as less down-growth of junctional epithelium. CONCLUSION: BMP-2/BioCaP could be a promising bone substitute for periodontal regeneration.

Concentrate Growth Factors Regulate Osteogenic Dysfunction of MC3T3-E1 Cells Induced by High Glucose Through PI3K/Akt Signaling Pathway.

INTRODUCTION: The aim of this study is to investigate the effects of Concentrate Growth Factors Extract (CGF-e) on the proliferation and osteogenic differentiation of MC3T3-E1 cells under high glucose condition. MATERIALS AND METHODS: MC3T3-E1 cells were divided into 4 groups including normal glucose (5.5-mM) group (control), high glucose (25.5-mM) group, normal glucose + CGF-e group, and high glucose + CGF-e group. The proliferation, osteogenic differentiation and mineralization of osteoblasts were evaluated, respectively, by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, cytoskeleton analysis, alkaline phosphatase activity assay, alizarin red staining, and real-time polymerase chain reaction. Western blots analysis was used to explore the role of PI3K/Akt pathway. RESULTS: The viability, osteogenic differentiation, and mineralization of MC3T3-E1 cells were significantly decreased by high glucose. All observed osteogenic dysfunction were inhibited by CGF-e. Moreover, the PI3K/Akt pathway was activated by CGF-e. CONCLUSIONS: It was concluded that the soluble factors released by CGF could significantly attenuate high glucose-mediated MC3T3-E1 cells osteogenic dysfunction through the PI3K/Akt pathway.

The Influence of Type 2 Diabetes Mellitus on the Osseointegration of Titanium Implants With Different Surface Modifications-A Histomorphometric Study in High-Fat Diet/Low-Dose Streptozotocin-Treated Rats.

OBJECTIVES: Type 2 diabetes mellitus (T2DM) is a systemic disease that also compromises the bone healing capacity. In healthy individuals, surface modifications of dental implants are proven to increase bone response and implant success. The aim of this study was to clarify if the surface modifications also improve osseointegration in a setting with diabetes mellitus. METHODS: T2DM was induced in 7 rats by a high-fat diet/low-dose streptozotocin injection. All animals received a hydroxyapatite (HA) implant, a sandblasted and acid-etched (SLA) implant, and a standard machined titanium implant for control in the tibia. After 4 weeks, thin-ground sections were produced, and the volume of new bone formation (nBV/TV) and bone-to-implant contact (nB.I/Im.I) were histomorphometrically analyzed. RESULTS: Both surface modifications led to an increase of osseointegration compared with the machined surface implant in rats with T2DM. nBV/TV was highest in the SLA implants, whereas nB.I/Im.I was highest in the HA group. Regardless of the surface modification, a superordinate regional pattern of new bone formation over the length of the implant was observed. CONCLUSIONS: Implants with HA coating and SLA surface modifications seem to have the potential to increase osseointegration also in T2DM rats when compared with a conventional machined surface.

A novel IRF6 mutation causing non-syndromic cleft lip with or without cleft palate in a pedigree.

Non-syndromic cleft lip with or without cleft palate (NSCLP) is the most common congenital craniofacial malformation, and its harmful influence on affected individuals is apparent. Despite many studies, the causative genes and their mechanisms are not completely clear. We recruited a Han Chinese NSCLP family and explored the causative variant in this pedigree. We performed whole-exome sequencing on two patients. Bioinformatics screening and analysis were used to identify the mutation. We also performed species conservation analysis, mutation function predictions, and homology protein modelling to evaluate the influence of the mutation. We identified a rare mutation in interferon regulatory factor 6 (IRF6) (c.26G>A; p.Arg9Gln) as a candidate of causative mutation. This mutation was predicted to be deleterious. The codon is conserved in many species. The residue change caused by this mutation would affect the structure of IRF6 to a degree. Our study suggested that the rare IRF6 variant is probably the pathogenic mutation in this family. Our result adds evidence that IRF6 variants play a role in the aetiology of orofacial clefts.

Strontium ion attenuates lipopolysaccharide-stimulated proinflammatory cytokine expression and lipopolysaccharide-inhibited early osteogenic differentiation of human periodontal ligament cells.

BACKGROUND AND OBJECTIVE: Periodontitis is a chronic inflammatory disease characterized by the destruction of the periodontium. The strontium ion (Sr2+ ) can prevent the bone loss associated with periodontitis and promote the regeneration of the bone. The mechanisms by which the Sr2+ works remain poorly understood. We aim to investigate the effects of the Sr2+ ion on cell proliferation, inflammatory regulation and osteogenic differentiation of human periodontal ligament cells (hPDLCs) in pathological conditions. MATERIAL AND METHODS: hPDLCs were obtained from premolars that came from the orthodontic extraction. The hPDLCs were treated with Sr2+ and/or lipopolysaccharide (LPS), which was applied as the pathological condition of periodontitis. The effect of the dose of Sr2+ on cell proliferation was analyzed using a Cell Counting Kit-8 assay. The gene and protein expression of proinflammatory cytokines were detected by the real-time polymerase chain reaction and enzyme-linked immunosorbent assay. The osteogenic differentiation and mineralization were assessed by the real-time polymerase chain reaction, alkaline phosphatase activity assay and alizarin red staining. RESULTS: Results demonstrated that Sr2+ in a range of concentrations from 0.02 to 2.5 mmol/L significantly improved the proliferation of hPDLCs. Sr2+ reversed LPS-stimulated proinflammatory cytokine expressions such as tumor necrosis factor alpha, interleukin (IL)-1ß, IL-6 and IL-8. Moreover, Sr2+ rescued the LPS-inhibited gene expression of osteogenic differentiation. Although it appeared to suppress the late mineralization, Sr2+ can reverse the LPS-inhibited early osteogenic differentiation of hPDLCs. CONCLUSION: These results indicated that Sr2+ could attenuate the LPS-stimulated proinflammatory molecule expression and inhibit early osteogenic differentiation of hPDLCs.

Group 5 ITI Consensus Report: Digital technologies.

OBJECTIVES: Working Group 5 was assigned the task to review the current knowledge in the area of digital technologies. Focused questions on accuracy of linear measurements when using CBCT, digital vs. conventional implant planning, using digital vs. conventional impressions and assessing the accuracy of static computer-aided implant surgery (s-CAIS) and patient-related outcome measurements when using s-CAIS were addressed. MATERIALS AND METHODS: The literature was systematically searched, and in total, 232 articles were selected and critically reviewed following PRISMA guidelines. Four systematic reviews were produced in the four subject areas and amply discussed in the group. After emendation, they were presented to the plenary where after further modification, they were accepted. RESULTS: Static computer-aided surgery (s-CAIS), in terms of pain & discomfort, economics and intraoperative complications, is beneficial compared with conventional implant surgery. When using s-CAIS in partially edentulous cases, a higher level of accuracy can be achieved when compared to fully edentulous cases. When using an intraoral scanner in edentulous cases, the results are dependent on the protocol that has been followed. The accuracy of measurements on CBCT scans is software dependent. CONCLUSIONS: Because the precision intraoral scans and of measurements on CBCT scans and is not high enough to allow for the required accuracy, s-CAIS should be considered as an additional tool for comprehensive diagnosis, treatment planning, and surgical procedures. Flapless s-CAIS can lead to implant placement outside of the zone of keratinized mucosa and thus must be executed with utmost care.

Comparative study on the incision healing of the palatal mucosa by using Er:YAG laser or traditional scalpel in the SD rats.

The aim of this study was to compare the histology of wound healing following incisions with the scalpel or the Er:YAG laser in the palatal mucosa of SD rats. Two types of wounds were performed with the stainless steel scalpel or the Er:YAG laser in the palatal mucosa of SD rats, while the adjacent untreated palatal mucosa was chosen as control. Rats were sacrificed on day 1, day 3, day 7, and day 30 post-surgery. Biopsy samples from each wound were examined and the expression of IL-1ß and TGF-ß1 was determined by enzyme-linked immunosorbent assay (ELISA). The early postoperative incision of the scalpel group had obvious bleeding and swelling, while the laser wound mainly covered the surface of white pseudomembrane. The infiltration of neutrophils and lymphocytes in the stroma of the scalpel incision was more than that of the laser group. Compared to the laser group, 1 and 3 days after operation, the TGF-ß1 content of the scalpel group were significantly increased (P = 0.032 and 0.019). Seven days after operation, the TGF-ß1 content of two groups was decreased. TGF-ß1 expression of control group was obviously increased (P > 0.05); 1, 3, and 7 days after operation, the traditional scalpel amount of IL-1ß expression was significantly higher than that of control group (P = 0.000, 0.000, and 0.001). Postoperative day 1, IL-1ß expression of laser group and control group had no significant difference (P = 0.572). Three days after operation, IL-1ß expression of laser incision was increased and was significantly higher than that in control group (P = 0.032), however lower than the scalpel group (P = 0.03). Seven days after operation, the IL-1ß expression of two groups had no significant difference (P = 0.333); however, the IL-1ß expression of two groups were significantly higher than that of the control group (P = 0.02 and 0.001). Compared to the traditional scalpel, the incision of Er:YAG laser has smaller inflammation reaction, more pseudomembrane coverage, and minimal damage of the mucoperiosteal tissue.

Clinical Factors Affecting the Accuracy of Guided Implant Surgery-A Systematic Review and Meta-analysis.

OBJECTIVES: To systematically review the current dental literature regarding clinical accuracy of guided implant surgery and to analyze the involved clinical factors. MATERIAL AND METHODS: PubMed and Cochrane Central Register of Controlled Trials were searched. Meta-analysis and meta-regression analysis were performed. Clinical studies with the following outcome measurements were included: (1) angle deviation, (2) deviation at the entry point, and (3) deviation at the apex. The involved clinical factors were further evaluated. RESULTS: Fourteen clinical studies from 1951 articles initially identified met the inclusion criteria. Meta-regression analysis revealed a mean deviation at the entry point of 1.25 mm (95% confidence interval [CI]: 1.22-1.29), 1.57 mm (95% CI: 1.53-1.62) at the apex, and 4.1° in angle (95% CI: 3.97-4.23). A statistically significant difference (P < .001) was observed in angular deviations between the maxilla and mandible. Partially guided surgery showed a statistically significant greater deviation in angle (P < .001), at the entry point (P < .001), and at the apex (P < .001) compared with totally guided surgery. The outcome of guided surgery with flapless approach indicated significantly more accuracy in angle (P < .001), at the entry point (P < .001), and at apex (P < .001). Significant differences were observed in angular deviation based on the use of fixation screw (P < .001). CONCLUSIONS: The position of guide, guide fixation, type of guide, and flap approach could influence the accuracy of computer-aided implant surgery. A totally guided system using fixation screws with a flapless protocol demonstrated the greatest accuracy. Future clinical research should use a standardized measurement technique for improved accuracy.

Alpha-Lipoic Acid Alleviates High-Glucose Suppressed Osteogenic Differentiation of MC3T3-E1 Cells via Antioxidant Effect and PI3K/Akt Signaling Pathway.

BACKGROUND/AIMS: Patients with diabetes mellitus have a higher risk of dental implant failure. One major cause is high-glucose induced oxidative stress. Alpha-lipoic acid (ALA), a naturally occurring compound and dietary supplement, has been established as a potent antioxidant that is a strong scavenger of free radicals. However, few studies have yet investigated the effect of ALA on osteogenic differentiation of osteoblasts cultured with high glucose medium. The aim of this study is to investigate the effects of ALA on the osteoblastic differentiation in MC3T3-E1 cells under high glucose condition. METHODS: MC3T3-E1 cells were divided into 4 groups including normal glucose (5.5 mM) group (control), high glucose (25.5 mM) group, high glucose + 0.1 mM ALA group, and high glucose + 0.2 mM ALA group. The proliferation, osteogenic differentiation and mineralization of cells were evaluated by MTT assay, alkaline phosphatase (ALP) activity assay, alizarin red staining and real time-polymerase chain reaction. High-glucose induced oxidative damage was also assessed by the production of reactive oxygen species (ROS) and superoxide dismutase (SOD). Western blots were performed to examine the role of PI3K/Akt pathway. RESULTS: The proliferation, osteogenic differentiation and mineralization of MC3T3-E1 cells were significantly decreased by the ROS induced by high-glucose. All observed oxidative damage and osteogenic dysfunction induced were inhibited by ALA. Moreover, the PI3K/Akt pathway was activated by ALA. CONCLUSIONS: We demonstrate that ALA may attenuate high-glucose mediated MC3T3-E1 cells dysfunction through antioxidant effect and modulation of PI3K/Akt pathway.