Application of three-dimensional printing individualized titanium mesh in alveolar bone defects with different Terheyden classifications: A retrospective case series study.

OBJECTIVE: To present the results of guided bone regeneration (GBR) with three-dimensional printing individualized titanium mesh (3D-PITM) applied to alveolar bone defects with different Terheyden classifications and the factors affecting the osteogenic outcome. MATERIALS AND METHODS: Fifty-nine patients, presenting with 61 defect sites, were enrolled between 2018 and 2021. GBR+3D-PITM was obtained with simultaneous or second stage implant placement. The complication rate, the success rate of the bone grafting procedure and the survival rate of the implant were documented. Bone gain, thickness of pseudo-periosteum and peri-implant marginal bone loss (MBL) were measured through digital methods by imaging data (CBCT and X-ray). RESULTS: Out of 61 sites, 20 were exposed (exposure rate: 32.8%). The width, height, and volume bone gain at P3 (mesh removal) were 5.22 ± 3.19 mm, 5.01 ± 2.83 mm, and 588.91 ± 361.23 mm3 , respectively. From P2 (3D-PITM+GBR) to P3 , changes in bone gain were not statistically different in the different Terheyden classifications, the occurrence of exposure (p < .001 for all dimensions) and the different type of pseudo-periosteum (p = .030 for width and p = .002 for height) were significantly correlated with the reduction of bone gain. Terheyden classification of the defect sites was significantly associated with the occurrence of exposure (p = .014) and types of the pseudo-periosteum (p = .015). CONCLUSION: The 3D-PITM can be used in alveolar bone defects with different Terheyden classification, but cases with severe vertical bone defects have a greater chance of the 3D-PITM exposure and the exposure can affect the outcome of bone augmentation.

Predicting the risk of dental implant loss using deep learning.

AIM: To investigate the feasibility of predicting dental implant loss risk with deep learning (DL) based on preoperative cone-beam computed tomography. MATERIALS AND METHODS: Six hundred and three patients who underwent implant surgery (279 high-risk patients who did and 324 low-risk patients who did not experience implant loss within 5 years) between January 2012 and January 2020 were enrolled. Three models, a logistic regression clinical model (CM) based on clinical features, a DL model based on radiography features, and an integrated model (IM) developed by combining CM with DL, were developed to predict the 5-year implant loss risk. The area under the receiver operating characteristic curve (AUC) was used to evaluate the model performance. Time to implant loss was considered for both groups, and Kaplan-Meier curves were created and compared by the log-rank test. RESULTS: The IM exhibited the best performance in predicting implant loss risk (AUC = 0.90, 95% confidence interval [CI] 0.84-0.95), followed by the DL model (AUC = 0.87, 95% CI 0.80-0.92) and the CM (AUC = 0.72, 95% CI 0.63-0.79). CONCLUSIONS: Our study offers preliminary evidence that both the DL model and the IM performed well in predicting implant fate within 5 years and thus may greatly facilitate implant practitioners in assessing preoperative risks.

Development of a rat model for type 2 diabetes mellitus peri-implantitis: A preliminary study.

OBJECTIVE: To develop an in vivo model to simulate the complex internal environment of diabetic peri-implantitis (T2DM-PI) model for a better understanding of peri-implantitis in type 2 diabetic patients. MATERIALS AND METHODS: Maxillary first molars were extracted in Sprague-Dawley (SD) rats, and customized cone-shaped titanium implants were installed in the extraction sites. Thereafter, implants were uncovered and customized abutments were screwed into implants. A high-fat diet and a low-dose injection of streptozotocin were utilized to induce T2DM. Finally, LPS was locally injected in implant sulcus to induce peri-implantitis. RESULTS: In the present study, T2DM-PI model has been successfully established. Imaging analysis revealed that abundant inflammatory cells infiltrated in the soft tissue in T2DM-PI group with concomitant excessive secretion of inflammatory cytokines. Moreover, higher expression of MMP and increased number of osteoclasts led to collagen disintegration and bone resorption in T2DM-PI group. CONCLUSIONS: These results describe a novel rat model which stimulate T2DM-PI in vivo, characterized by overwhelming inflammatory response and bone resorption. This model has a potential to be used for investigation of initiation, progression and interventional therapy of T2DM-PI.

The effect of bone defect size on the 3D accuracy of alveolar bone augmentation performed with additively manufactured patient-specific titanium mesh.

OBJECTIVE: Additively manufactured (3D-printed) titanium meshes have been adopted in the dental field as non-resorbable membranes for guided bone regeneration (GBR) surgery. However, according to previous studies, inaccuracies between planned and created bone volume and contour are common, and many reasons have been speculated to affect its accuracy. The size of the alveolar bone defect can significantly increase patient-specific titanium mesh design and surgical difficulty. Therefore, this study aimed to analyze and investigate the effect of bone defect size on the 3D accuracy of alveolar bone augmentation performed with additively manufactured patient-specific titanium meshes. METHODS: Twenty 3D-printed patient-specific titanium mesh GBR surgery cases were enrolled, in which 10 cases were minor bone defect/augmentation (the planned bone augmentation surface area is less than or equal to 150 mm2 or one tooth missing or two adjacent front-teeth/premolars missing) and another 10 cases were significant bone defect/augmentation (the planned bone augmentation surface area is greater than 150 mm2 or missing adjacent teeth are more than two (i.e. ≥ three teeth) or missing adjacent molars are ≥ two teeth). 3D digital reconstruction/superposition technology was employed to investigate the bone augmentation accuracy of 3D-printed patient-specific titanium meshes. RESULTS: There was no significant difference in the 3D deviation distance of bone augmentation between the minor bone defect/augmentation group and the major one. The contour lines of planned-CAD models in two groups were basically consistent with the contour lines after GBR surgery, and both covered the preoperative contour lines. Moreover, the exposure rate of titanium mesh in the minor bone defect/augmentation group was slightly lower than the major one. CONCLUSION: It can be concluded that the size of the bone defect has no significant effect on the 3D accuracy of alveolar bone augmentation performed with the additively manufactured patient-specific titanium mesh.

Impact of diabetes mellitus simulations on bone cell behavior through in vitro models.

Diabetes mellitus (DM) is related to impaired bone healing and an increased risk of bone fractures. While it is recognized that osteogenic differentiation and the function of osteoblasts are suppressed in DM, the influence of DM on osteoclasts is still unclear. Hyperglycemia and inflammatory environment are the hallmark of DM that causes dysregulation of various pro-inflammatory cytokines and alternated gene expression in periodontal ligament cells, osteoblasts, osteocytes, osteoclasts, and osteoclast precursors. A methodological review on conceptual and practical implications of in vitro study models is used for DM simulation on bone cells. Several major databases were screened to find literature related to the study objective. Published literature within last 20 years that used in vitro DM-simulated models to study how DM affects the cellular behavior of bone cells were selected for this review. Studies utilizing high glucose and serum acquired from diabetic animals are the mainly used methods to simulate the diabetic condition. The combination with various simulating factors such as lipopolysaccharide (LPS), hydrogen peroxide (H2O2), and advanced glycation end products (AGEs) have been reported in diabetic situations in vitro, as well. Through screening procedure, it was evident DM-simulated conditions exerted negative impact on bone-related cells. However, inconsistent results were found among different reported studies, which could be due to variation in culture conditions, concentrations of the stimulating factors and cell lineage, etc. This manuscript has concisely reviewed currently existing DM-simulated in vitro models and provides valuable insights of detailed components in simulating DM conditions in vitro. Studies using DM-simulated microenvironment revealed that in vitro simulation negatively impacted periodontal ligament cells, osteoblasts, osteocytes, osteoclasts, and osteoclast precursors. Contrarily, studies also indicated beneficial influence on bone-related cells when such conditions are reversed.

Inertio-capillary cross-streamline drift of droplets in Poiseuille flow using dissipative particle dynamics simulations.

We find using dissipative particle dynamics (DPD) simulations that a deformable droplet sheared in a narrow microchannel migrates to steady-state position that depends upon the dimensionless particle capillary number , which controls the droplet deformability (with Vmax the centerline velocity, µf the fluid viscosity, Γ the surface tension, R the droplet radius, and H the gap), the droplet (particle) Reynolds number , which controls inertia, where ρ is the fluid density, as well as on the viscosity ratio of the droplet to the suspending fluid κ = µd/µf. We find that when the Ohnesorge number is around 0.06, so that inertia is stronger than capillarity, at small capillary number Cap < 0.1, the droplet migrates to a position close to that observed for hard spheres by Segre and Silberberg, around 60% of the distance from the centerline to the wall, while for increasing Cap the droplet steady-state position moves smoothly towards the centerline, reaching around 20% of the distance from centerline to the wall when Cap reaches 0.5 or so. For higher Oh, the droplet position is much less sensitive to Cap, and remains at around 30% of the distance from centerline to the wall over the whole accessible range of Cap. The results are insensitive to viscosity ratios from unity to the highest value studied here, around 13, and the drift towards the centerline for increasing Cap is observed for ratios of droplet diameter to gap size ranging from 0.1 to 0.3. We also find consistency between our predictions and existing perturbation theory for small droplet or particle size, as well as with experimental data. Additionally, we assess the accuracy of the DPD method and conclude that with current computer resources and methods DPD is not readily able to predict cross-stream-line drift for small particle Reynolds number (much less than unity), or for droplets that are less than one tenth the gap size, owing to excessive noise and inadequate numbers of DPD particles per droplet.

Inertial migration of a rigid sphere in plane Poiseuille flow as a test of dissipative particle dynamics simulations.

After reviewing and organizing the literature on the problem of inertial cross-stream migration of rigid spheres in various geometries including tubes and channels, we use Dissipative Particle Dynamics (DPD) simulations to study the simplest case of migration of a single neutrally or non-neutrally buoyant sphere with diameter 20% of the gap in plane Poiseuille flow and assess the potential and limitations of DPD simulations for this and similar problems. We find that the neutrally buoyant sphere lags by up to 6% behind the surrounding fluid and is focused at a position around 50% of the distance between the channel center and the wall. With Re increasing from around 100 to 500, the sphere migrates closer to the channel center. With flow driven by gravity, a much denser non-neutrally buoyant sphere leads the surrounding fluid and is focused at a position closer to the wall, around 60% the distance from the channel center to the wall, in qualitative agreement with previous work. The lower values of the Schmidt number Sc in DPD simulations relative to real fluids, due to the relatively large diffusivity of DPD beads, are shown to not significantly affect the consistency of our DPD results with literature results although they make results noisy at low Re (i.e., ≲ 50). However, the increase in Ma and Wi with increasing Re leads to compressible flow effects and in some cases viscoelastic effects at high Re depending on the DPD parameters chosen. Even for optimally chosen parameters, we require Re ≲ 500 to avoid strong compressibility effects. Thus, the relative simplicity of the DPD method for complex fluid flows is offset by the need to control the effects of unphysically high values of other parameters, such as Ma and Wi, which seriously limits the range of conditions under which DPD simulations give valid results in fluid transport problems.

Selective intra-arterial infusion of rAd-p53 with chemotherapy for advanced oral cancer: a randomized clinical trial.

BACKGROUND: In this study, a combination of recombinant adenoviral p53 (rAd-p53) gene therapy and intra-arterial delivery of chemotherapeutic agents for treatment of oral squamous cell carcinoma was evaluated. METHODS: In total, 99 patients with stage III or IV oral carcinoma who had refused or were ineligible for surgery were enrolled in a randomized, placebo-controlled, double-blind, phase III clinical trial. They were randomly assigned to group I (n = 35; intra-arterial infusion of rAd-p53 plus chemotherapy), group II (n = 33; intra-arterial infusion of rAd-p53 plus placebo chemotherapy), or group III (n = 31; intra-arterial infusion of placebo rAd-p53 plus chemotherapy). RESULTS: The median length of follow-up was 36 months (range, 3 to 86 months). During follow-up, 16 patients in group I, 20 in group II, and 22 in group III died. Group I (48.5%) had a higher complete response rate than groups II (16.7%) and III (17.2%) (P = 0.006). The rate of non-responders in group I was significantly lower than that in groups II and III (P < 0.020). A log-rank test for survival rate indicated that group I had a significantly higher survival rate than group III (P = 0.019). The survival rate of patients with stage III but not stage IV oral cancer was significantly higher in group I than in group III (P = 0.015, P = 0.200, respectively). The survival rate of patients with stage IV did not differ significantly among the three groups. Or the 99 patients, 63 patients experienced adverse events of either transient flu-like symptoms or bone marrow suppression, while 13 patients had both these conditions together. No replication-deficient virus was detected in patient serum, urine, or sputum. rAd-p53 treatment increased Bax expression in the primary tumor of 80% of patients, as shown by immunohistochemical staining. CONCLUSIONS: Intra-arterial infusion of combined rAd-p53 and chemotherapy significantly increased the survival rate of patients with stage III but not stage IV oral cancer, compared with intra-arterial chemotherapy. Intra-arterial infusion of combined rAd-p53 and chemotherapy may represent a promising alternative treatment for oral squamous cell carcinoma. TRIAL REGISTRATION: ChiCTR-TRC-09000392 (Date of registration: 2009-05-18).

3D-printed customised titanium mesh and bone ring technique for bone augmentation of combined bone defects in the aesthetic zone.

PURPOSE: Complex bone defects with a horizontal and vertical combined deficiency pose a clinical challenge in implant dentistry. This study reports the case of a young female patient who presented with a perforating bone defect in the aesthetic zone. MATERIALS AND METHODS: Based on prosthetically guided bone regeneration, virtual 3D bone augmentation was planned. A 3D printed customised titanium mesh and the autogenous bone ring technique were then utilised simultaneously to achieve a customised bone contour. After 6 months, the titanium mesh was removed and connective tissue grafting was performed. Finally, implants were placed and the provisional and definitive prostheses were delivered following a digital approach. Vertical and horizontal bone gain, new bone density, pseudo-periosteum type and marginal bone loss were measured. Planned bone volume, regenerated bone volume and regeneration rate were analysed. RESULTS: Staged tooth shortening led to a coronal increase in keratinised mucosa. The customised titanium mesh and bone ring technique yielded 14.27 mm vertical bone gain and 12.9 mm horizontal bone gain in the perforating area. When the titanium mesh was removed, the reopening surgery showed a Type 1 pseudo-periosteum (none or < 1 mm), and CBCT scans revealed a new bone density of ~550 HU. With a planned bone volume of 1063.55 mm3, the regenerated bone volume was 969.29 mm3, indicating a regeneration rate of 91.14%. The 1-year follow-up after definitive restoration revealed no complications except for 0.55 to 0.60 mm marginal bone loss. CONCLUSION: Combined application of customised titanium mesh and an autogenous bone ring block shows promising potential to achieve prosthetically guided bone regeneration for complex bone defects in the aesthetic zone.

Machine learning-enabled high-throughput industry screening of edible oils.

Long-term consumption of mixed fraudulent edible oils increases the risk of developing of chronic diseases which has been a threat to the public health globally. The complicated global supply-chain is making the industry malpractices had often gone undetected. In order to restore the confidence of consumers, traceability (and accountability) of every level in the supply chain is vital. In this work, we shown that machine learning (ML) assisted windowed spectroscopy (e.g., visible-band, infra-red band) produces high-throughput, non-destructive, and label-free authentication of edible oils (e.g., olive oils, sunflower oils), offers the feasibility for rapid analysis of large-scale industrial screening. We report achieving high-level of discriminant (AUC > 0.96) in the large-scale (n ≈ 11,500) of adulteration in olive oils. Notably, high clustering fidelity of 'spectral fingerprints' achieved created opportunity for (hypothesis-free) self-sustaining large database compilation which was never possible without machine learning. (137 words).

Nutritional load in post-prandial oxidative stress and the pathogeneses of diabetes mellitus.

Diabetes mellitus affected more than 500 million of people globally, with an annual mortality of 1.5 million directly attributable to diabetic complications. Oxidative stress, in particularly in post-prandial state, plays a vital role in the pathogenesis of the diabetic complications. However, oxidative status marker is generally poorly characterized and their mechanisms of action are not well understood. In this work, we proposed a new framework for deep characterization of oxidative stress in erythrocytes (and in urine) using home-built micro-scale NMR system. The dynamic of post-prandial oxidative status (against a wide variety of nutritional load) in individual was assessed based on the proposed oxidative status of the red blood cells, with respect to the traditional risk-factors such as urinary isoprostane, reveals new insights into our understanding of diabetes. This new method can be potentially important in drafting guidelines for sub-stratification of diabetes mellitus for clinical care and management.

Virtual sketching-based dental anatomy module improves learners' abilities to use computer-aided design to create dental restorations and prostheses.

Dental anatomy education for dental technology students should be developed in alignment with digital dental laboratory practices. We hypothesized that a virtually assisted sketching-based dental anatomy teaching module could improve students' acquisition of skills essential for digital restoration design. The second-year dental technology curriculum included a novel virtual technology-assisted sketching-based module for dental anatomy education. Pre- and post-course assessments evaluated students' skill sets and knowledge bases. Computer-aided design (CAD) scores were analyzed after one year to assess how the skills students developed through this module impacted their subsequent CAD performance. Participants who undertook the dental sketching-based teaching module demonstrated significantly improved theoretical knowledge of dental anatomy, dental aesthetic perception, and spatial reasoning skills. A partial least squares structural equation model indicated that the positive effects of this module on subsequent CAD performance were indirectly mediated by dental aesthetic perception, spatial reasoning, and practice time. A virtually assisted sketching-based dental anatomy teaching module significantly improved students' acquisition of skills and knowledge and positively mediated dental technology students' CAD performance.

Facile and Programmable Capillary-Induced Assembly of Prototissues via Hanging Drop Arrays.

An important goal for bottom-up synthetic biology is to construct tissue-like structures from artificial cells. The key is the ability to control the assembly of the individual artificial cells. Unlike most methods resorting to external fields or sophisticated devices, inspired by the hanging drop method used for culturing spheroids of biological cells, we employ a capillary-driven approach to assemble giant unilamellar vesicles (GUVs)-based protocells into colonized prototissue arrays by means of a coverslip with patterned wettability. By spatially confining and controllably merging a mixed population of lipid-coated double-emulsion droplets that hang on a water/oil interface, an array of synthetic tissue-like constructs can be obtained. Each prototissue module in the array comprises multiple tightly packed droplet compartments where interfacial lipid bilayers are self-assembled at the interfaces both between two neighboring droplets and between the droplet and the external aqueous environment. The number, shape, and composition of the interconnected droplet compartments can be precisely controlled. Each prototissue module functions as a processer, in which fast signal transports of molecules via cell-cell and cell-environment communications have been demonstrated by molecular diffusions and cascade enzyme reactions, exhibiting the ability to be used as biochemical sensing and microreactor arrays. Our work provides a simple yet scalable and programmable method to form arrays of prototissues for synthetic biology, tissue engineering, and high-throughput assays.

A Brief Review on Medicinal Plants-At-Arms against COVID-19.

COVID-19 pandemic caused by the novel SARS-CoV-2 has impacted human livelihood globally. Strenuous efforts have been employed for its control and prevention; however, with recent reports on mutated strains with much higher infectivity, transmissibility, and ability to evade immunity developed from previous SARS-CoV-2 infections, prevention alternatives must be prepared beforehand in case. We have perused over 128 recent works (found on Google Scholar, PubMed, and ScienceDirect as of February 2023) on medicinal plants and their compounds for anti-SARS-CoV-2 activity and eventually reviewed 102 of them. The clinical application and the curative effect were reported high in China and in India. Accordingly, this review highlights the unprecedented opportunities offered by medicinal plants and their compounds, candidates as the therapeutic agent, against COVID-19 by acting as viral protein inhibitors and immunomodulator in (32 clinical trials and hundreds of in silico experiments) conjecture with modern science. Moreover, the associated foreseeable challenges for their viral outbreak management were discussed in comparison to synthetic drugs.

Evaluation of surgical placement accuracy of customized CAD/CAM titanium mesh using screws-position-guided template: A retrospective comparative study.

BACKGROUND: Customized computer-aided-design/computer-aided-manufacturing (CAD/CAM) titanium meshes have been adopted for alveolar bone augmentation. But the inaccuracies between planned and created bone volume/contour are quite common, and the surgical placement of the customized mesh was considered as the first critical factor. However, the evaluation of surgical placement accuracy of customized mesh is currently lacking. PURPOSE: The aim of this study was to evaluate the accuracy of the surgical placement of customized meshes. METHODS: A total of 30 cases, 20 without the screws-position-guided template and 10 with the screws-position-guided template, were included in this study. The cone beam CT (CBCT) data sets of pre- and postoperative were converted into 3D models and digitally aligned. Then the actual placement of customized mesh and retainer titanium screws was compared to the virtual one to assess the surgical placement accuracy of customized mesh. At least 6 months after surgery, a new CBCT was taken and converted into 3D models. Planned bone volume, created bone volume, vertical bone augmentation, healing complications rate, pseudo-periosteum rate, exposure rate, and infection rate were all evaluated. RESULTS: The 3D digital reconstruction/registration analysis showed that the average difference between actual placement and planned one of customized mesh in positive and negative directions was 2.69 ± 0.70 mm and -1.41 ± 0.90 mm, respectively, without the screws-position-guided template. And the mean difference values between the actual and planned placement of the screws on the X and Y axes were 0.74 ± 0.85 mm and 0.89 ± 0.84 mm. In contrast, with the screws-position-guided template, the results were 2.38 ± 0.69 mm and -1.30 ± 1.13 mm. Accordingly, the mean difference values of screws were 0.76 ± 0.84 mm and 0.94 ± 0.72 mm. There was no statistical difference between the two groups, and the noninferiority of the control group compared to the test group was also confirmed by the comparative analysis. CONCLUSION: It can be concluded that there is a certain deviation between the planned surgical placement and actual one of customized mesh, and using screws-position-guided template is of limited help for its accurate placement. Further research is needed to achieve precise surgical placement of the customized mesh to achieve precise alveolar bone augmentation.

Portable Handheld "SkinPen" Loaded with Biomaterial Ink for In Situ Wound Healing.

In situ bioprinting has emerged as an attractive tool for directly depositing therapy ink at the defective area to adapt to the irregular wound shape. However, traditional bioprinting exhibits an obvious limitation in terms of an unsatisfactory bioadhesive effect. Here, a portable handheld bioprinter loaded with biomaterial ink is designed and named "SkinPen". Gelatin methacrylate (GelMA) and Cu-containing bioactive glass nanoparticles (Cu-BGn) serve as the main components to form the hydrogel ink, which displays excellent biocompatibility and antibacterial and angiogenic properties. More importantly, by introducing ultrasound and ultraviolet in a sequential programmed manner, the SkinPen achieves in situ instant gelation and amplified (more than threefold) bioadhesive shear strength. It is suggested that ultrasound-induced cavitation and the resulting topological entanglement contribute to the enhanced bioadhesive performance together. Combining the ultrasound-enhanced bioadhesion with the curative role of the hydrogel, the SkinPen shows a satisfactory wound-healing effect in diabetic rats. Given the detachable property of the SkinPen, the whole device can be put in a first-aid kit. Therefore, the application scenarios can be expanded to many kinds of accidents. Overall, this work presents a portable handheld SkinPen that might provide a facile but effective approach for clinical wound management.

Assessment of Customized Alveolar Bone Augmentation Using Titanium Scaffolds vs Polyetheretherketone (PEEK) Scaffolds: A Comparative Study Based on 3D Printing Technology.

Customized alveolar bone augmentation provides sufficient and precisely regenerated bone tissue for subsequent dental implant placement. Although some clinical cases have confirmed the successful use of the patient-specific polyetheretherketone (PEEK) scaffolds, the biomechanical property and osteogenic performance of the patient-specific PEEK scaffolds remain unclear. The objectives of this study were (1) to evaluate the space maintenance capacity and osteogenic performance of the patient-specific PEEK scaffolds for customized alveolar bone augmentation and (2) to compare the biomechanical properties of three-dimensionally printed titanium scaffolds and PEEK scaffolds. Both titanium scaffolds and PEEK scaffolds were designed and manufactured via additive manufacturing technology combined with computer-aided design (CAD). In three-point bending tests, the bending strength of the PEEK scaffold was about 1/3 that of the titanium scaffold. Accordingly, the equivalent strain value of the internal bone graft beneath the PEEK scaffold was about 3 times that beneath the titanium scaffold in finite element analysis, but the maximum deformations of both scaffolds were less than 0.05 mm. Meanwhile, in in vivo experiments, it is demonstrated that both scaffolds have similar space maintenance capacity and bone ingrowth efficiency. In conclusion, patient-specific PEEK scaffolds showed significantly lower biomechanical strength but comparable space maintenance and osteogenic properties to the titanium counterpart. Compared with traditional guided bone regeneration (GBR) surgery, both patient-specific PEEK and titanium scaffolds can achieve excellent osteogenic space maintenance ability. This study provides a preliminary basis for the clinical translation of the nonmetallic barrier membrane in customized alveolar bone augmentation.

Explant culture: an efficient method to isolate adipose-derived stromal cells for tissue engineering.

Enzymatic digestion, the commonly used method of adipose-derived stromal cells isolation, is time consuming and expensive, especially when applied to large volumes of tissue. In the present study, the characteristics of the cells obtained by adipose tissue explant culture were studied. We found that adipose tissue fragments could adhere onto the growth surface of flasks in a very short time after plating and that fibroblast-like cells migrated from the explants and reached confluence. Morphologic analysis and surface markers expression suggested the mesenchymal origin of the cells derived from adipose tissue explants. After in vitro expansion these cells were successfully induced into adipogenic, osteogenic, and chondrogenic lineages, which demonstrated their multipotency. The high growth rate and colony-forming efficiency of explant-derived cells were similar to those of cells obtained by digestion. Furthermore, explant culture gave higher yield of cells than digestion method after primary culture. The experiment of ectopic adipogenesis in nude mice suggested the prospects for tissue engineering of these cells. In conclusion, we obtained multipotent stromal cells from adipose tissue by explant culture, and this method was simple, time saving, and gave a high yield of cells. Therefore, explant culture can be used as an effective way to isolate adipose-derived stromal cells for tissue engineering.

Radiographic Evaluation of the Alveolar Ridge Splitting Technique Combined with Guided Bone Regeneration vs Guided Bone Regeneration Alone in the Anterior Maxilla: A Retrospective Controlled Study.

This study aimed to estimate the radiographic outcomes of the alveolar ridge splitting (ARS) technique combined with guided bone regeneration (GBR) and compare its efficacy with GBR alone in maxillary anterior narrow ridges. Forty patients with 51 implants in the ARS group and 40 patients with 49 implants in the GBR group were included. The buccal bone thickness (BBT) at 0 to 4 mm from the implant shoulder immediately and 6 months postoperative were analyzed using cone beam computed tomography. The BBT at both time points had no statistical disparities between the two groups (P > .05). However, BBT changes indicated significant disparities, with more BBT preservation in the ARS group (P < .05). Compared with GBR alone, the ARS technique combined with GBR, despite obvious buccal bone diminution, could be a reliable modality for treating ridge width deficiency in the anterior maxilla.

Research on the dimensional accuracy of customized bone augmentation combined with 3D-printing individualized titanium mesh: A retrospective case series study.

BACKGROUND: Few studies have focused on the dimensional accuracy of customized bone grafting by means of guided bone regeneration (GBR) with 3D-Printed Individual Titanium Mesh (3D-PITM). PURPOSE: Digital technologies were applied to evaluate the dimensional accuracy of customized bone augmentation with 3D-PITM with a two-stage technique. MATERIALS AND METHODS: Sixteen patients were included in this study. The CBCT data of post-GBR (immediate post-GBR) and post-implantation (immediate post-implant placement) were 3D reconstructed and compared with the pre-surgical planned bone augmentation. The dimensional differences were evaluated by superimposition using the Materialize 3-matic software. RESULTS: The superimposition analysis showed that the maximum deviations of contour between were 3.4 mm, and the average differences of the augmentation contour were 0.5 ± 0.4 and 0.6 ± 0.5 mm respectively. The planned volume of bone regeneration was approximately equal to the amount of regenerated bone present 6 to 9 months after the surgical procedure. On average, the vertical gain in bone height was about 0.5 mm less than planned. And, the horizontal bone gain on the straight buccal of the dental implants and 2 to 4 mm apical of the platform fell also about a 0.5 mm short on average. Statistically significant differences were observed between the augmented volume of virtual and post-GBR, and the horizontal bone gain of post-implantation on the level of 4 mm apical to the implant platform (P < .05). CONCLUSIONS: The dimensional accuracy of customized bone augmentation with the 3D-PITM approach needs further improvement and compared to other surgical approaches of bone augmentation.