Soluble expression of hMYDGF was improved by strain engineering and optimizations of fermentation strategies in Escherichia coli.

Myeloid-derived growth factor (MYDGF) is a cytokine that exhibits a variety of biological functions. This study focused on utilizing BL21(DE3) strain engineering and fermentation strategies to achieve high-level expression of soluble human MYDGF (hMYDGF) in Escherichia coli. Initially, the E. coli expressing strain BL21(DE3) was engineered by deleting the IpxM gene and inserting the GROEL/S and Trigger factor genes. The engineered E. coli strain BL21(TG)/pT-MYDGF accumulated 3557.3 ± 185.6 µg/g and 45.7 ± 6.7 mg/L of soluble hMYDGF in shake flask fermentation, representing a 15.6-fold increase compared to the control strain BL21(DE3)/pT-MYDGF. Furthermore, the yield of hMYDGF was significantly enhanced by optimizing the fermentation conditions. Under optimized conditions, the 5L bioreactor yielded up to 2665.8 ± 164.3 µg/g and 407.6 ± 42.9 mg/L of soluble hMYDGF. The results indicate that the implementation of these optimization strategies could enhance the ratio and yield of soluble proteins expressed by E.coli, thereby meeting the demands of industrial production. This study employed sophisticated strategies to lay a solid foundation for the industrial application of hMYDGF.

Synthesis and evaluation of 5,15-diaryltetrabenzoporphyrins as photosensitizers for photo-diagnosis and photodynamic activity of tumors.

Photodynamic therapy (PDT) is a well-established treatment modality, typically conducted with single-wavelength irradiation, which may not always be optimal for varying tumor locations and sizes. To address this, photosensitizers with absorption wavelengths ranging from 550 to 760 nm are being explored. Herein, a series of 5,15-diaryltetrabenzoporphyrins (Ar2TBPs) were synthesized. All compounds displayed obvious absorption at 550-700 nm (especially at ∼668 nm), intense fluorescence, efficient generation of singlet oxygen and good photodynamic antitumor effects. Notably, compound I3 (5,15-bis[(4-carboxymethoxy)phenyl]tetrabenzoporphyrin) showed excellent cytotoxicity against Eca-109 cell line upon red light irradiation, with an IC50 value of 0.45 µM, and phototherapeutic index of 25.8. Flow cytometry revealed that I3 could induce distinct cell apoptosis. In vivo studies revealed that compound I3 selectively accumulated at tumor site and exhibited outstanding PDT effect with antitumor activity under single-time administration and light irradiation, and revealed more efficiency than the clinical photosensitizer Verteporfin. These findings underscore the considerable promise of I3 as a robust theranostic agent, offering capabilities in real-time fluorescence imaging and serving as a potent photosensitizer for personalized and precise photodynamic therapy of tumors.

Overexpression of METTL14 mediates steatohepatitis and insulin resistance in mice.

Background: Lipid accumulation and redox imbalance, resulting from dysregulation of hepatic fatty acids oxidation, contribute to the development of steatohepatitis and insulin resistance. Recently, dysregulated RNA N6-methyladenosine (m6A) methylation modification has been found involving fatty liver. However, the role of methyltransferase-like 14 (METTL14), the core component of m6A methylation, in the development of steatohepatitis is unknown. Herein, we aimed to explore the role of METTL14 on steatohepatitis and insulin resistance in mice with metabolic dysfunction-associated steatotic liver disease (MASLD). Methods: The liver tissues of mice and patients with MASLD were collected to detect the expression of METTL14. METTL14 overexpression and METTL14 silence were used to investigate the effect of METTL14 on lipid metabolism disorder in vivo and in vitro. Knockout of METTL14 in primary hepatocytes was used to investigate the role of Sirtuin 1 (SIRT1) on lipid accumulation induced by METTL14. Results: METTL14 was dramatically up-regulated in the livers of db/db mice, high-fat diet (HFD)-fed mice, and patients with MASLD. METTL14 overexpression exacerbated MASLD and promoted lipid metabolism disorder and insulin resistance in mice. Conversely, METTL14 knockout ameliorated lipid deposition and insulin resistance in HFD-fed mice. Furthermore, METTL14 overexpression facilitated lipid accumulation, while METTL14 knockout reduced lipid accumulation in HepG2 cells and primary hepatocytes. In addition, METTL14 lost up-regulated SIRT1 expression in hepatocytes. SIRT1 deficiency abrogated the ameliorating effects of METTL14 downregulation in MASLD mice. Conclusions: These findings suggest that dysfunction of the METTL14-SIRT1 pathway might promote hepatic steatosis and insulin resistance.

TLR9 activation in large wound induces tissue repair and hair follicle regeneration via γδT cells.

The mechanisms underlying tissue repair in response to damage have been one of main subjects of investigation. Here we leverage the wound-induced hair neogenesis (WIHN) models in adult mice to explore the correlation between degree of damage and the healing process and outcome. The multimodal analysis, in combination with single-cell RNA sequencing help to explore the difference in wounds of gentle and heavy damage degrees, identifying the potential role of toll-like receptor 9 (TLR9) in sensing the injury and regulating the immune reaction by promoting the migration of γδT cells. The TLR9 deficient mice or wounds injected with TLR9 antagonist have greatly impaired healing and lower WIHN levels. Inhibiting the migration of γδT cells or knockout of γδT cells also suppress the wound healing and regeneration, which can't be rescued by TLR9agonist. Finally, the amphiregulin (AREG) is shown as one of most important effectors secreted by γδT cells and keratinocytes both in silicon or in the laboratory, whose expression influences WIHN levels and the expression of stem cell markers. In total, our findings reveal a previously unrecognized role for TLR9 in sensing skin injury and influencing the tissue repair and regeneration by modulation of the migration of γδT cells, and identify the TLR9-γδT cells-areg axis as new potential targets for enhancing tissue regeneration.

Multiobjective Optimization of Papermaking Wastewater Treatment Processes under Economic, Energy, and Environmental Goals.

Due to the heterogeneity of recycled paper materials and the production conditions, pollutants in papermaking wastewater fluctuate sharply over time. Quality control of the papermaking wastewater treatment process (PWTP) is challenging and costly. As regulations are also growing about the environmental effects of the PWTP on greenhouse gas (GHG) emission, energy consumption, etc., the PWTP formulates a complex multiobjective optimization problem. This research established a multiagent deep reinforcement learning framework to simultaneously optimize process cost, energy consumption, and GHG emission in the PWTP, subjected to the effluent quality, to realize economic, energy, and environmental (3E) goals. The biological treatment process of wastewater in paper mills was simulated using benchmark simulation model no. 1 (BSM1). The data generated based on the BSM manual was utilized for model training, and real data acquired from a local papermaking factory was used to estimate the model performance. The results show that the proposed method outperforms conventional techniques in identifying the best control strategies for multiple targets.

Integrated-omics profiling unveils the disparities of host defense to ECM scaffolds during wound healing in aged individuals.

Extracellular matrix (ECM) scaffold membranes have exhibited promising potential to better the outcomes of wound healing by creating a regenerative microenvironment around. However, when compared to the application in younger individuals, the performance of the same scaffold membrane in promoting re-epithelialization and collagen deposition was observed dissatisfying in aged mice. To comprehensively explore the mechanisms underlying this age-related disparity, we conducted the integrated analysis, combing single-cell RNA sequencing (scRNA-Seq) with spatial transcriptomics, and elucidated six functionally and spatially distinctive macrophage groups and lymphocytes surrounding the ECM scaffolds. Through intergroup comparative analysis and cell-cell communication, we characterized the dysfunction of Spp1+ macrophages in aged mice impeded the activation of the type Ⅱ immune response, thus inhibiting the repair ability of epidermal cells and fibroblasts around the ECM scaffolds. These findings contribute to a deeper understanding of biomaterial applications in varied physiological contexts, thereby paving the way for the development of precision-based biomaterials tailored specifically for aged individuals in future therapeutic strategies.

Optical Amplification at 1.5 µm in ErIII Coordination Polymer-Doped Waveguides Based on Intramolecular Energy Transfer.

9,9-bis (diphenylphosphorylphenyl) fluorene (FDPO) and dibenzotetrathienoacene (DBTTA), are synthesized as the neutral and anionic ligands, respectively, to prepare the ErIII coordination polymer [Er(DBTTA)3(FDPO)]n. Based on the intramolecular energy transfer, optical gains at 1.5 µm are demonstrated in [Er(DBTTA)3(FDPO)]n-doped polymer waveguides under excitations of low-power light-emitting diodes (LEDs) instead of laser pumping. A ligand-sensitization scheme between organic ligands and Er3+ ions under an excitation of an ultraviolet (UV) LED is established. Relative gains of 10.5 and 8.5 dB cm-1 are achieved at 1.53 and 1.55 µm, respectively, on a 1-cm-long SU-8 channel waveguide with a cross-section of 2 × 3 µm2 and a 1.5-µm-thick [Er(DBTTA)3(FDPO)]n-doped polymethylmethacrylate (PMMA) as upper cladding. The ErIII coordination polymer [Er(DBTTA)3(FDPO)]n can be conveniently integrated with various low-loss inorganic waveguides to compensate for optical losses in the C-band window. Moreover, by relying on the intramolecular energy transfer and UV LED top-pumping technology, it is easy to achieve coupling packaging of erbium-doped waveguide amplifiers (EDWAs) with pump sources in planar photonic integrated chips, effectively reducing the commercial costs.

Ligand-mediate exciton allocation enables efficient cluster-based white light-emitting diodes via single and heavy doping.

Despite potential in high-resolution and low-cost displays and lighting, multi-doping structures and low concentrations (<1%) limit repeatability and stability of single-emissive-layer white light-emitting devices. Herein, we report a singly doped white-emitting system of blue thermally activated delayed fluorescence host matrix (CzAcSF) doped by yellow Cu4I4 cluster ([tBCzDppy]2Cu4I4). CzAcSF:x% [tBCzDppy]2Cu4I4 films realize photo- and electro-luminescence colors from cool white to warm white at x = 20-40. The external quantum efficiency of 23.5% was achieved at x = 30, indicating the record-high efficiency among solution-processed analogs and the largest doping concentration among efficient white light-emitting devices. It shows that di(tert-butyl)carbazole moieties in [tBCzDppy]2Cu4I4 provide high-lying excited energy levels at~2.6 eV to mediate energy transfer from CzAcSF (2.9 eV) to coordinated Cu4I4 (2.2 eV). Our results demonstrate the antenna effect of ligands on optimizing charge and energy transfer in organic-cluster systems and superiority of white cluster light-emitting diodes in practical applications.

Fatigue crack-based strain sensors achieving flow detection and motion monitoring for reconnaissance robot applications.

Crack-based flexible strain sensors with ultra-high sensitivity under tiny strain are highly desired for environmental perception and motion detection of novel flexible and miniature robots. However, previously reported methods for fabricating crack patterns have often sacrificed the cyclic stability of the sensor, leading to a trade-off relationship between the sensitivity and the cyclic stability. Here, a universal and simple strategy based on fatigue loading with an ultra-large cumulative strain of up to ∼1.2 × 107%, rather than the traditionally quasi-static pre-overloading methods, is proposed to introduce channel cracks in the sensing layer without sacrificing the cyclic stability. The developed flexible strain sensors exhibit high strain-sensitivity (gauge factor = 5798) under tiny strain (< 3%), high cyclic stability (15 000 cycles) and a low strain detecting limit (0.02%). Furthermore, a leaf-like mechanosensor is developed using the fatigue crack-based strain sensor for the realization of multifunctional applications in environment perception and micro-motion detection. Brilliant airflow sensing performance with a wide sensing range (0.93-11.93 m s-1) and a fast response time (0.28 s) for amphibious applications is demonstrated. This work provides a new strategy for overcoming limits of crack-based flexible strain sensors and the developed leaf-like mechanosensor shows great application potential in miniature and flexible reconnaissance robots.

Phosphine Oxide-Nd3+ Coordination Chains with Cumulated Output Enable Efficient LED-Pumping Optical Amplification.

Near-infrared luminescent rare-earth organic complexes have attracted intensive attention in the field of optical waveguide amplification. However, their optical gains were commonly less than 4 dB/cm due to limited doping concentrations. Herein, two one-dimensional (1D) Nd3+ coordination chains, namely, [Nd(TTA)3(DBTDPO)]n (Nd1) and [Nd(TTA)3(DPEPO)]n (Nd2), bridged by phosphine oxide ligands were developed for the neodymium-doped waveguide amplifier. Despite its P-P distance being similar to DBTDPO, the different P═O orientation of DPEPO renders markedly shorter intra- and interchain Nd-Nd distances for Nd2 in comparison to Nd1. Furthermore, the weaker intermolecular interactions alleviate the quenching effect for Nd2. Therefore, Nd2 can provide more locally concentrated and radiative Nd3+ ions, leading to a larger Nd3+-characteristic 1.06 µm emission intensity and duration than Nd1. Based on embedded and evanescent-field waveguide structures, Nd2 achieves state-of-the-art gain maxima of 5.7 and 4.9 dB/cm as well as outstanding gain stability. These results indicate that controllable coordination assembly of lanthanide ions in multidimension provides a flexible approach to combine local high-density outputs and effective suppression of quenching.

Molecular Characterization of High and Low Virulent Escherichia coli Clinical Strains Isolated from Patients with Urinary Tract Infections with or without Bacteremia in Southern Taiwan.

Objective: The most common extraintestinal pathogen and infection site is uropathogenic Escherichia coli (UPEC), which causes urinary tract infections (UTIs). UPEC is also a common pathogen in bloodstream infections; in severe cases, it can lead to death. Although host and bacterial virulence factors have been demonstrated to be associated with UTI pathogenesis, the role of the related contributing factors in UTI and urinary source bacteremia is not yet fully understood. This study aimed to compare and analyze the factors contributing to urinary bacteremia in patients with UTI. Methods: A total of 171 E. coli strains collected from patients with UTI and urinary source bacteremia at Chiayi Christian Hospital were used. Phylogenetic groups and virulence factors were determined using PCR. Drug resistance patterns were determined using the disk diffusion assay. Results: Previous studies have demonstrated that fimbriae and papGII may be associated with first-step infections and severe UTIs, respectively. As expected, highly virulent E. coli strains (belonging to the phylogenetic B2 and D groups) were dominant in the bacteremic UTI (90%) and UTI (86.27%) groups. However, our results showed that the UTI group had a significantly higher prevalence of sfa/focDE (belonging to the S and FIC fimbriae) than the bacteremic UTI group (29.4% vs 12.5%; p=0.008). In the bacteremic group, we found that sfa/focDE was only detected in highly virulent strains. The bacteremic UTI group had a significantly higher prevalence of papGII (belonging to P fimbriae) than the UTI group (55.8% vs 37.3%; p=0.026). In addition, the P fimbriae gene cluster, including papC, papEF, and papGII, was predominant in highly virulent strains. Notably, our results show that multidrug-resistant (MDR) strains were significantly less virulent than non MDR strains. Conclusion: Taken together, our results provide insights into the contributing factors in patients with UTI and urinary bacteremia.

Investigating the effects of buccal bone fenestration on maxillary anterior implants: A 1- to 6-year retrospective study.

PURPOSE: To examine the effects of buccal bone fenestration on maxillary anterior implants. MATERIALS AND METHODS: Patients who underwent implant placement in the maxillary anterior region between January 2017 and December 2021 and had received final restorations 1 to 6 years prior were screened for inclusion in the present study. Propensity score matching was used to match the two-group sample size and reduce the influence of potential confounding factors. Generalised linear mixed models were employed to evaluate the correlation between buccal bone fenestration and peri-implant marginal bone loss. RESULTS: A total of 42 patients with 50 implants were included in the study, 16 of whom had buccal bone fenestration (group 1) and 26 of whom did not (group 2). No implant failures occurred, resulting in a cumulative implant survival rate of 100.0%. There was no statistically significant difference between the pink aesthetic scores for the two groups. The mean marginal bone loss was 0.44 ± 0.46 mm for group 1 and 0.33 ± 0.32 mm for group 2 (P > 0.05). Buccal bone fenestration was not the influencing factor of marginal bone loss (P > 0.05). Marginal bone loss was greater around implants used to replace canines than those inserted to replace central incisors (P < 0.05). Far less marginal bone loss occurred around immediately loaded implants than delayed implants with cover screws (P < 0.05). When there is sufficient keratinised mucosa around the implant, marginal bone loss will decrease significantly (P < 0.05). CONCLUSIONS: Within the limitations of this study, buccal bone fenestration defects around dental implants cannot influence peri-implant bone loss. CONFLICT-OF-INTEREST STATEMENT: The authors report no conflicts of interest relating to this study.

Biological fermentation pilot-scale systems and evaluation for commercial viability towards sustainable biohydrogen production.

Featuring high caloric value, clean-burning, and renewability, hydrogen is a fuel believed to be able to change energy structure worldwide. Biohydrogen production technologies effectively utilize waste biomass resources and produce high-purity hydrogen. Improvements have been made in the biohydrogen production process in recent years. However, there is a lack of operational data and sustainability analysis from pilot plants to provide a reference for commercial operations. In this report, based on spectrum coupling, thermal effect, and multiphase flow properties of hydrogen production, continuous pilot-scale biohydrogen production systems (dark and photo-fermentation) are established as a research subject. Then, pilot-scale hydrogen production systems are assessed in terms of sustainability. The system being evaluated, consumes 171,530 MJ of energy and emits 9.37 t of CO2 eq when producing 1 t H2, and has a payback period of 6.86 years. Our analysis also suggests future pathways towards effective biohydrogen production technology development and real-world implementation.

Delayed room temperature phosphorescence enabled by phosphines.

Organic ultralong room-temperature phosphorescence (RTP) usually emerges instantly and immediately decays after excitation removal. Here we report a new delayed RTP that is postponed by dozens of milliseconds after excitation removal and decays in two steps including an initial increase in intensity followed by subsequent decrease in intensity. The delayed RTP is achieved through introduction of phosphines into carbazole emitters. In contrast to the rapid energy transfer from single-molecular triplet states (T1) to stabilized triplet states (Tn*) of instant RTP systems, phosphine groups insert their intermediate states (TM) between carbazole-originated T1 and Tn* of carbazole-phosphine hybrids. In addition to markedly increasing emission lifetimes by ten folds, since TM → Tn* transition require >30 milliseconds, RTP is thereby postponed by dozens of milliseconds. The emission character of carbazole-phosphine hybrids can be used to reveal information through combining instant and delayed RTP, realizing multi-level time resolution for advanced information, biological and optoelectronic applications.

The VAMP-associated protein VAP27-1 plays a crucial role in plant resistance to ER stress by modulating ER-PM contact architecture in Arabidopsis.

The endoplasmic reticulum (ER) and the plasma membrane (PM) form ER-PM contact sites (EPCSs) that allow the ER and PM to exchange materials and information. Stress-induced disruption of protein folding triggers ER stress, and the cell initiates the unfolded protein response (UPR) to resist the stress. However, whether EPCSs play a role in ER stress in plants remains unclear. VESICLE-ASSOCIATED MEMBRANE PROTEIN (VAMP)-ASSOCIATED PROTEIN 27-1 (VAP27-1) functions in EPCS tethering and is encoded by a family of 10 genes (VAP27-1-10) in Arabidopsis thaliana. Here, we used CRISPR-Cas9-mediated genome editing to obtain a homozygous vap27-1 vap27-3 vap27-4 (vap27-1/3/4) triple mutant lacking three of the key VAP27 family members in Arabidopsis. The vap27-1/3/4 mutant exhibits defects in ER-PM connectivity and EPCS architecture, as well as excessive UPR signaling. We further showed that relocation of VAP27-1 to the PM mediates specific VAP27-1-related EPCS remodeling and expansion under ER stress. Moreover, the spatiotemporal dynamics of VAP27-1 at the PM increase ER-PM connectivity and enhance Arabidopsis resistance to ER stress. In addition, we revealed an important role for intracellular calcium homeostasis in the regulation of UPR signaling. Taken together, these results broaden our understanding of the molecular and cellular mechanisms of ER stress and UPR signaling in plants, providing additional clues for improving plant broad-spectrum resistance to different stresses.

Vascularized fascial flap for reconstruction of combined oral mucosa-mandibular defects: The multi-modal biological assessment.

OBJECTIVE: The reconstruction of composite defects in the oral and maxillofacial region using vascularized fascial flaps, such as the fibular, iliac, and temporal fascial flaps, has gained increasing attention among surgeons. However, there remains uncertainty regarding the suitability of fascial flaps as transplants, as well as their healing processes and outcomes, due to their non-mucosal nature. This study aims to comprehensively assess the biological aspects of vascularized fascial flaps at clinical, histological, and genetic levels, with the goal of providing essential biological references for their clinical application. STUDY DESIGN: This study enrolled three patients who underwent reconstruction of combined oral mucosa-mandibular defects using fibular vascularized fascial flaps between 2020 and 2023. Data regarding changes in the appearance of the fascial flaps, bulk-RNA sequencing, and histological slices of initial fascia, initial gingiva, and transformed fascia were collected and analyzed. RESULTS: Within three months, the fascial flaps exhibited rapid epithelial coverage and displayed distinct characteristics resembling mucosa. High-throughput RNA sequencing analyses and histological slices revealed that the transformed fascia exhibited tissue structures similar to mucosa and demonstrated unique advantages in promoting blood vessel formation and reducing scarring through the high-level expression of relevant genes. CONCLUSION: These findings emphasize the potential and feasibility of utilizing vascularized fascial flaps for oral mucosa reconstruction, establishing their unique advantage as transplant materials, and providing significant biological information and references for their selection and clinical application.

PaCHNOC: Packet and Circuit Hybrid Switching NoC for Real-Time Parallel Stream Signal Processing.

Real-time heterogeneous parallel embedded digital signal processor (DSP) systems process multiple data streams in parallel in a stringent time interval. This type of system on chip (SoC) requires the network on chip (NoC) to establish multiple symbiotic parallel data transmission paths with ultra-low transmission latency in real time. Our early NoC research PCCNOC meets this need. The PCCNOC uses packet routing to establish and lock a transmission circuit, so that PCCNOC is perfectly suitable for ultra-low latency and high-bandwidth transmission of long data packets. However, a parallel multi-data stream DSP system also needs to transmit roughly the same number of short data packets for job configuration and job execution status reports. While transferring short data packets, the link establishment routing delay of short data packets becomes relatively obvious. Our further research, thus, introduced PaCHNOC, a hybrid NoC in which long data packets are transmitted through a circuit established and locked by routing, and short data packets are attached to the routing packet and the transmission is completed during the routing process, thus avoiding the PCCNOC setup delay. Simulation shows that PaCHNOC performs well in supporting real-time heterogeneous parallel embedded DSP systems and achieves overall latency reduction 65% compared with related works. Finally, we used PaCHNOC in the baseband subsystem of a real 5G base station, which proved that our research is the best NoC for baseband subsystem of 5G base stations, which reduce 31% comprehensive latency in comparison to related works.

Comprehensive kinetic modeling and product distribution for pyrolysis of pulp and paper mill sludge.

Pyrolysis holds immense potential for clean treatment of pulp and paper mill sludge (PPMS), enabling efficient energy and chemical recovery. However, current understanding of PPMS pyrolysis kinetics and product characteristics remains incomplete. This study conducted detailed modeling of pyrolysis kinetics for two typical PPMSs from a wastepaper pulp and paper mill, namely, deinking sludge (PPMS-DS) and sewage sludge (PPMS-SS), and analyzed comprehensively pyrolysis products. The results show that apparent activation energy of PPMS-DS (169.25-226.82 kJ/mol) and PPMS-SS (189.29-411.21 kJ/mol) pyrolysis undergoes significant change, with numerous parallel reactions present. A distributed activation energy model with dual logistic distributions proves to be suitable for modeling thermal decomposition kinetics of both PPMS-DS and PPMS-SS, with coefficient of determination >0.999 and relative root mean square error <1.99 %. High temperature promotes decomposition of solid organic materials in PPMS, and maximum tar yield for both PPMS-DS (53.90 wt%, daf) and PPMS-SS (56.48 wt%, daf) is achieved at around 500 °C. Higher levels of styrene (24.45 % for PPMS-DS and 14.71 % for PPMS-SS) and ethylbenzene (8.61 % for PPMS-DS and 8.33 % for PPMS-SS) are detected in tar and could be used as chemicals. This work shows great potential to propel development of PPMS pyrolysis technology, enabling green and sustainable production in pulp and paper industry.

The three-dimensional stability and accuracy of 3D printing surgical templates: An In Vitro study.

OBJECTIVE: To evaluate the three-dimensional (3D) stability and accuracy of additively manufactured surgical templates fabricated using two different 3D printers and materials. MATERIALS AND METHODS: Forty surgical templates were designed and printed using two different 3D printers: the resin group (n = 20) used a digital light processing (DLP) 3D printer with photopolymer resin, and the metal group (n = 20) employed a selective laser melting (SLM) 3D printer with titanium alloy. All surgical templates were scanned immediately after production and re-digitalized after one month of storage. Similarly, the implant simulations were performed twice. Three-dimensional congruency between the original design and the manufactured surgical templates was quantified using the root mean square (RMS), and the definitive and planned implant positions were determined and compared. RESULTS: At the postproduction stage, the metal templates exhibited higher accuracy than the resin templates (p < 0.001), and these differences persisted after one month of storage (p < 0.001). The resin templates demonstrated a significant decrease in three-dimensional stability after one month of storage (p < 0.001), whereas the metal templates were not affected (p > 0.05). No significant differences in implant accuracy were found between the two groups. However, the resin templates showed a significant increase in apical and angular deviations after one month of storage (p < 0.001), whereas the metal templates were not affected (p > 0.05). CONCLUSION: Printed metal templates showed higher fabrication accuracy than printed resin templates. The three-dimensional stability and implant accuracy of printed metal templates remained unaffected by one month of storage. CLINICAL SIGNIFICANCE: With superior three-dimensional stability and acceptable implant accuracy, printed metal templates can be considered a viable alternative technique for guided surgery.

Guided bone regeneration for peri-implant augmentation: A retrospective study comparing two surgical techniques with a mean follow-up of 26 months.

OBJECTIVES: To introduce a modified guided bone regeneration (GBR) technique using intact periosteum and deproteinized bovine bone mineral (DBBM) for peri-implant augmentation and compare the clinical outcomes with those of conventional GBR. MATERIALS AND METHODS: Patients who received peri-implant augmentation in posterior sites between 2015 and 2021 were reviewed in this study. Group A was treated with a modified GBR technique, and Group B was treated with conventional GBR. For group comparison, propensity score matching was performed with a sensitivity analysis. The implant survival rate, dimensional changes in hard tissue, marginal bone loss (MBL), and peri-implant parameters were evaluated. RESULTS: In total, 114 implants from 98 patients were included. The implant survival rates were 95.74% in Group A and 95.00% in Group B during the follow-up period. At 6 months, the median horizontal thickness was recorded at 0.87 mm (IQ1-IQ3 = 0.00-1.75 mm) in Group A, exhibiting a relatively lower value compared to the corresponding measurement of 0.98 mm (IQ1-IQ3 = 0.00-1.89 mm) in Group B (p = .937). Vertical height displayed no statistically significant intergroup difference between the two groups (p = .758). The mean follow-up period was 25.83 ± 12.93 months after loading in Group A and 27.47 ± 21.29 months in Group B (p = .761). MBL and peri-implant parameters were comparable between the two groups. CONCLUSIONS: Within the limitations of this study, the modified GBR technique using intact periosteum and DBBM grafting might be a viable alternative to correct bone defects around implants in molar and premolar sites.