Expert consensus on odontogenic maxillary sinusitis multi-disciplinary treatment.

ABSTARCT: Odontogenic maxillary sinusitis (OMS) is a subtype of maxillary sinusitis (MS). It is actually inflammation of the maxillary sinus that secondary to adjacent infectious maxillary dental lesion. Due to the lack of unique clinical features, OMS is difficult to distinguish from other types of rhinosinusitis. Besides, the characteristic infectious pathogeny of OMS makes it is resistant to conventional therapies of rhinosinusitis. Its current diagnosis and treatment are thus facing great difficulties. The multi-disciplinary cooperation between otolaryngologists and dentists is absolutely urgent to settle these questions and to acquire standardized diagnostic and treatment regimen for OMS. However, this disease has actually received little attention and has been underrepresented by relatively low publication volume and quality. Based on systematically reviewed literature and practical experiences of expert members, our consensus focuses on characteristics, symptoms, classification and diagnosis of OMS, and further put forward multi-disciplinary treatment decisions for OMS, as well as the common treatment complications and relative managements. This consensus aims to increase attention to OMS, and optimize the clinical diagnosis and decision-making of OMS, which finally provides evidence-based options for OMS clinical management.

Multifunctional MXene-doped photothermal microneedles for drug-resistant bacteria-infected wound healing.

Skin injuries and drug-resistant bacterial infections pose serious challenges to human health. It is essential to establish a novel multifunctional platform with good anti-infection and wound-healing abilities. In this study, a new MXene-doped composite microneedle (MN) patch with excellent mechanical strength and photothermal antibacterial and ROS removal properties has been developed for infected wound healing. When the MN tips carrying the MXene nanosheets are inserted into the cuticle of the skin, they will quickly dissolve and subsequently release the nanomaterials into the subcutaneous infection area. Under 808 nm NIR irradiation, the MXene, as a "nano-thermal knife", sterilizes and inhibits bacterial growth through synergistic effects of sharp edges and photothermal antibacterial activity. Furthermore, ROS caused by injury and infection can be cleared by MXene-doped MNs to avoid excessive inflammatory responses. Based on the synergistic antibacterial and antioxidant strategy, the MXene-doped MNs have demonstrated excellent wound-healing properties in an MRSA-infected wound model, such as promoting re-epithelialization, collagen deposition, and angiogenesis and inhibiting the expression of pro-inflammatory factors. Therefore, the multifunctional MXene-doped MN patches provide an excellent alternative for clinical drug-resistant bacteria-infected wound management.

MXene-Functionalized Ferroelectric Nanocomposite Membranes with Modulating Surface Potential Enhance Bone Regeneration.

Rapid and effective bone defect repair remains a challenging issue for clinical treatment. Applying biomaterials with endogenous surface potential has been widely studied to enhance bone regeneration, but how to regulate the electric potential and surface morphology of the implanted materials precisely to achieve an optimal bioelectric microenvironment is still a major challenge. The aim of this study is to develop electroactive biomaterials that better mimic the extracellular microenvironment for bone regeneration. Hence, MXene/polyvinylidene fluoride (MXene/PVDF) ferroelectric nanocomposite membranes were prepared by electrospinning. Physicochemical characterization demonstrated that Ti3C2Tx MXene nanosheets were wrapped in PVDF shell layer and the surface morphology and potential were modulated by altering the content of MXene, where uniform distribution of fibers and enhanced electric potential can be obtained and precisely assembled into a natural extracellular matrix (ECM) in bone tissue. Consequently, the MXene/PVDF membranes facilitated cell adhesion, stretching, and growth, showing good biocompatibility; meanwhile, their intrinsic electric potential promoted the recruitment of osteogenic cells and accelerated the differentiation of osteoblast. Furthermore, 1 wt % MXene/PVDF membrane with a suitable surface potential and better topographical structure for bone regeneration qualitatively and quantitatively promoted bone tissue formation in a rat calvarial bone defect after 4 and 8 weeks of healing. The fabricated MXene/PVDF ferroelectric nanocomposite membranes show a biomimetic microenvironment with a sustainable electric potential and optimal 3D topographical structure, providing an innovative and well-suited strategy for application in bone regeneration.

Graphene and its derivatives: "one stone, three birds" strategy for orthopedic implant-associated infections.

Orthopedic implants provide an avascular surface for microbial attachment and biofilm formation, impeding the entry of immune cells and the diffusion of antibiotics. The above is an important cause of dental and orthopedic implant-associated infection (IAI). For the prevention and treatment of IAI, the drawbacks of antibiotic resistance and surgical treatment are increasingly apparent. Due to their outstanding biological properties such as biocompatibility, immunomodulatory effects, and antibacterial properties, graphene-based nanomaterials (GBNs) have been applied to bone tissue engineering to deal with IAI, and in particular have great potential application in drug/gene carriers, multi-functional platforms, and coating forms. Here we review the latest research progress and achievements in GBNs for the prevention and treatment of IAI, mainly including their biomedical applications for antibacterial and immunomodulation effects, and for inducing osteogenesis. Furthermore, the biosafety of graphene family materials in bone tissue regeneration and the feasibility of clinical application are critically analyzed and discussed.

Clinical and radiographic outcomes of customized allogeneic bone block versus autogenous bone block for ridge augmentation: 6 Month results of a randomized controlled clinical trial.

AIM: To evaluate the efficacy of customized allogeneic bone block (CABB) for ridge augmentation compared with autogenous bone block. MATERIALS AND METHODS: Patients (N = 24) in need of ridge augmentation were randomly assigned to one of two treatment modalities: CABBs (CABB group) and autogenous bone blocks (ABB group). The primary outcome of the present study was the horizontal bone gain at 1 mm below the alveolar ridge crest (HBG1 ). Secondary outcomes were the bone gain at other levels, bone resorption rate, ridge width, operative time, postoperative pain score, and histological results. The data obtained from the current study were analysed using a generalized linear mixed effects model, two-sample t-test, or a Mann-Whitney U-test. RESULTS: Twenty-four patients completed a 6-month follow-up. One patient in the CABB group exhibited block exposure. The CABB group had significantly more horizontal bone gain (HBG1 ) and less horizontal bone resorption (HBRR1 ) at 1 mm below the alveolar ridge crest when compared with those in the ABB group (HBG1 : CABB group [4.29 ± 1.48 mm] and ABB group [1.12 ± 3.25 mm]; HBRR0 : CABB group [42.15 ± 14.03%] and ABB group [92.52 ± 55.78%], p < .05). In addition, a longer operative time was reported in the ABB group compared with the CABB group (p < .05). The histological observation indicated a new bone formation in both groups. CONCLUSIONS: The use of CABBs resulted in more horizontal bone gain and less horizontal bone resorption at 1 mm below the alveolar ridge crest at 6 months post-surgery compared with ABBs while reducing the operative time in the treatment of ridge augmentation.

Comparison of the accuracy of immediate implant placement using static and dynamic computer-assisted implant system in the esthetic zone of the maxilla: a prospective study.

PURPOSE: This study aimed to compare the accuracy of fully guided between dynamic and static computer-assisted implant surgery (CAIS) systems for immediate implant placement in the esthetic zone. METHODS: A total of 40 qualified patients requiring immediate implant placement in the esthetic zone were randomly and equally assigned to either static CAIS group (n = 20) or dynamic CAIS groups (n = 20). Global deviations at entry, apex, and angular deviation between placed and planned implant position were measured and compared as primary outcomes. Secondary outcomes were the deviation of implant placement at mesial-distal, labial-palatal, and coronal-apical directions. RESULTS: For the immediate implant placement, the mean global entry deviations in static and dynamic CAIS groups were 0.99 ± 0.63 mm and 1.06 ± 0.55 mm (p = 0.659), while the mean global apex deviations were 1.50 ± 0.75 mm and 1.18 ± 0.53 mm (p = 0.231), respectively. The angular deviation in the static and dynamic CAIS group was 3.07 ± 2.18 degrees and 3.23 ± 1.67 degrees (p = 0.547). No significant differences were observed for the accuracy parameters of immediate implant placement between static and dynamic CAIS systems, except the deviation of the implant at entry in the labial-palatal direction in the dynamic CAIS group was significantly more labial than of the static CAIS (p = 0.005). CONCLUSIONS: This study demonstrated that clinically acceptable accuracy of immediate implant placement could be achieved using static and dynamic CAIS systems. Trial registration ChiCTR, ChiCTR2200056321. Registered 3 February 2022, http://www.chictr.org.cn/showproj.aspx?proj=151348.

A full digital workflow to prefabricate an implant-supported interim restoration: case report and a novel technique.

This article describes a case with a full digital procedure to prefabricate an implant-supported interim restoration based on the preoperative digital implant planning. A fully guided surgical template is designed and printed, and then an interim restoration is fabricated based on the planned implant position through a dental computer-aided design (CAD) software. Once the implant was placed at the predetermined position through the fully guided surgical guide, the prefabricated interim restoration could be inserted immediately after the surgery, which can guide the healing of the soft tissue and enhance the esthetic outcomes. This novel technique eliminates the conventional impression making to insert an implant-supported interim restoration immediately after the implant placement surgery, which can guide the healing of the soft tissue, minimize the chairside time and optimize the clinical workflow.

Electrophoretic-deposited MXene titanium coatings in regulating bacteria and cell response for peri-implantitis.

Background: Two-dimensional(2D)MXenes have continued to receive increasing interest from researchers due to their graphene-like properties, in addition to their versatile properties for applications in electronic devices, power generation, sensors, drug delivery, and biomedicine. However, their construction and biological properties as titanium coatings to prevent peri-implantitis are still unclear. Materials and methods: In this work, few-layer Ti3C2Tx MXene coatings with different thicknesses at varied depositing voltages (30, 40, and 50 V) were constructed by anodic electrophoretic deposition without adding any electrolytic ions. In vitro cytocompatibility assay was performed on preosteoblasts (MC3T3-E1) cell lines after the characterization of the coating. Meanwhile, the antibacterial activity against bacteria which are closely related to peri-implantitis including Staphylococcus aureus (S. aureus) and its drug-resistant strain MRSA was further investigated. Results: MXene-coated titanium models with different thicknesses were successfully assembled by analyzing the results of characterization. The compounding of Ti3C2Tx could significantly improve the initial adhesion and proliferation of MC3T3-E1 cells. Moreover, the coating can effectively inhibit the adhesion and cell activity of S. aureus and MRSA, and MRSA expressed greater restricting behavior than S. aureus. The ability to promote antibacterial activity is proportional to the content of Ti3C2Tx. Its antioxidant capacity to reduce ROS in the culture environment and bacterial cells was first revealed. Conclusion: In summary, this work shows a new avenue for MXene-based nano-biomaterials under the clinical problem of multiple antibiotic resistance.

Recent advances and trends in the applications of MXene nanomaterials for tissue engineering and regeneration.

MXene, as a new two-dimensional nanomaterial, is endowed with lots of particular properties, such as large surface area, excellent conductivity, biocompatibility, biodegradability, hydrophilicity, antibacterial activity, and so on. In the past few years, MXene nanomaterials have become a rising star in biomedical fields including biological imaging, tumor diagnosis, biosensor, and tissue engineering. In this review, we sum up the recent applications of MXene nanomaterials in the field of tissue engineering and regeneration. First, we briefly introduced the synthesis and surface modification engineering of MXene. Then we focused on the application and development of MXene and MXene-based composites in skin, bone, nerve and heart tissue engineering. Uniquely, we also paid attention to some research on MXene with few achievements at present but might become a new trend in tissue engineering and regeneration in the future. Finally, this paper will also discuss several challenges faced by MXene nanomaterials in the clinical application of tissue engineering.

3D printing of Ti3C2-MXene-incorporated composite scaffolds for accelerated bone regeneration.

Grafting of bone-substitute biomaterials plays a vital role in the reconstruction of bone defects. However, the design of bioscaffolds with osteoinductive agents and biomimetic structures for regeneration of critical-sized bone defects is difficult. Ti3C2MXene-belonging to a new class of 2D nanomaterials-exhibits excellent biocompatibility, and antibacterial properties, and promotes osteogenesis. However, its application in preparing 3D-printed tissue-engineered bone scaffolds for repairing bone defects has not been explored. In this work, Ti3C2MXene was incorporated into composite scaffolds composed of hydroxyapatite and sodium alginate via extrusion-based 3D printing to evaluate its potential in bone regeneration. MXene composite scaffolds were fabricated and characterized by SEM, XPS, mechanical properties and porosity. The biocompatibility and osteoinductivity of MXene composite scaffolds were evaluated by cell adhesion, cell counting kit-8 test, quantitative real-time polymerase chain reaction, alkaline phosphatase activity and alizarin red S tests of bone mesenchymal stem cells (BMSCs). A rat calvarial defect model was performed to explore the osteogenic activity of the MXene composite scaffoldsin vivo. The results showed the obtained scaffold had a uniform structure, macropore morphology, and high mechanical strength.In vitroexperimental results revealed that the scaffold exhibited excellent biocompatibility with BMSCs, promoted cell proliferation, upregulated osteogenic gene expression, enhanced alkaline phosphatase activity, and promoted mineralized-nodule formation. The experimental results confirmed that the scaffold effectively promoted bone regeneration in a model of critical-sized calvarial- bone-defectin vivoand promoted bone healing to a significantly greater degree than scaffolds without added Ti3C2MXene did. Conclusively, the Ti3C2MXene composite 3D-printed scaffolds are promising for clinical bone defect treatment, and the results of this study provide a theoretical basis for the development of practical applications for tissue-engineered bone scaffolds.

Size-dependent photothermal antibacterial activity of Ti3C2Tx MXene nanosheets against methicillin-resistant Staphylococcus aureus.

Developing antibiotics-independent antibacterial materials is of great importance for combating drug-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). MXene (transition metal carbides and nitrides), a class of novel 2D nanomaterials, has shown great potentials in biomedical areas. However, the effect of MXene size on its properties and bioactivity is still unknown. Herein, we report for the first time that the antibacterial photothermal therapy efficacy of Ti3C2Tx MXene nanosheets is size-dependent. Three MXene suspensions with small size of 196 nm (MX-s), medium size of 347 nm (MX-m) and large size of 497 nm (MX-l) were prepared via ultrasonication. Upon NIR irradiation for 5 min, the temperature of MXene suspensions (10 µg/mL) increased to 64, 60 and 56 °C for MX-s, MX-m and MX-l, respectively. Accordingly, the viability loss of MRSA induced by MX-s, MX-m and MX-l under NIR was 93%, 69% and 56%, respectively. The in vivo study in the MRSA-infected mouse model showed that the photothermal therapy efficacy of MX-s was comparable to that of the positive control vancomycin. This is the first report on the size-dependent photothermal effect and photothermal antibacterial activity of MXene, which may guide the development of MXene-based therapeutics in the future. In addition, the drug-free antibacterial therapy has great implications for the treatment of antibiotics-resistant bacteria infections.

Enhanced Antibacterial Activity of Indocyanine Green-Loaded Graphene Oxide via Synergistic Contact Killing, Photothermal and Photodynamic Therapy.

Methicillin-resistant Staphylococcus aureus (MRSA) has become a serious threat to human's health. Recently, photodynamic/photothermal therapy (PDT/PTT) has emerged as promising strategies against antibiotics-resistant pathogens due to their broad antibacterial spectrum and negligible resistance. In this work, the photosensitizer indocyanine green (ICG) was loaded on graphene oxide (GO) nanosheets with good encapsulation efficiency high to 92.31%. Under near-infrared (NIR) irradiation, the anti-MRSA efficiency of GO (20 µg/ml), ICG (5 µg/ml) and ICG-GO (5 µg/ml-20 µg/ml) was 33.76%, 40.15% and 99.86%, respectively. We further showed that NIR irradiation mildly increased the temperature to 43.1 °C for ICG-GO, and lead to the highest reactive oxygen species (ROS) generation (316.51% and 157.11% compared to ICG alone and GO alone). In conclusion, ICG-GO has a great potential for antibacterial treatment due to its synergistic contact killing, photothermal and photodynamic activity.

Influence of anatomical factors related to maxillary sinus on outcomes of transcrestal sinus floor elevation.

BACKGROUND/PURPOSE: Graft bone maturation and remodeling in the maxillary sinus require adequate angiogenesis and osteoprogenitor cells migration from the surrounding bony walls and Schneiderian membrane. This study aimed to evaluate the influence of anatomical factors related to maxillary sinus on the outcomes of transcrestal sinus floor elevation using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Forty-five patients (63 elevated sites) were included in this study. CBCT were obtained preoperatively, immediately and 6 months after surgery. The anatomical features of residual bone height, maxillary sinus width, maxillary sinus angle and Schneiderian membrane thickness were measured on preoperative CBCT. Descriptive statistics and correlation analysis were conducted to evaluate the influence of anatomical factors on outcome parameters, including sinus lift height, graft bone resorption and marginal bone loss. RESULTS: The results showed that there was a positive correlation between sinus width and graft bone resorption. A significantly positive correlation between sinus angle and graft bone resorption was also found. CONCLUSION: Our findings indicate that the anatomical factors of maxillary sinus (sinus width and sinus angle) have influence on the linear change of bone grafts after transcrestal sinus floor elevation.

Identification of potential druggable targets of cell cycle with small-molecule inhibitors in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumors worldwide and there are few crucial regulators and druggable targets for early diagnosis. Therefore, the identification of biomarkers for the early diagnosis and druggable targets of OSCC is imminent. In this study, we integrated gene set enrichment analysis, differential gene expression analysis based on the negative binomial distribution, weighted correlation network analysis, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes into analyzing the OSCC cohort downloaded from The Cancer Genome Atlas, and found that cell cycle and related biologic processes are significantly enriched. Then, we constructed the core gene network of OSCC, which showed the connection of encode human Cyclin-A2 protein, encode RAD51-associated protein 1, encode human centromere-associated protein E (CENPE), encode humans centromere protein I (CENPI) and encode polo-like kinase 1 (PLK1) to several cell cycle-related genes. Survival analysis further showed that low expression of these genes was associated with a better prognosis. Furthermore, we utilized a high-throughput virtual screening to find new CENPE and PLK1 inhibitors, and one of the CENPE inhibitor DB04517 suppressed the proliferation of OSCC cells by cell cycle arrest of cell cycle. Taken together, these candidate regulators could serve as the candidate diagnostic and prognostic biomarkers for OSCC, and specific suppression of these genes may be a potential approach to prevent and treat OSCC with the candidate inhibitors.

Lateral Ridge Augmentation with Guided Bone Regeneration Using Particulate Bone Substitutes and Injectable Platelet-Rich Fibrin in a Digital Workflow: 6 Month Results of a Prospective Cohort Study Based on Cone-Beam Computed Tomography Data.

This study aimed to test whether or not a digital workflow for GBR with particulate bone substitutes and injectable platelet-rich fibrin improved the thickness of the hard tissue compared to the conventional workflow. 26 patients in need of lateral bone augmentation were enrolled. GBR with particulate bone substitutes and injectable platelet-rich fibrin was performed in all patients. Patients were divided into two groups: control (conventional workflow; n = 14) and test (digital workflow; n = 12). CBCT scans were performed before surgery, immediately after wound closure, and 6 months post-surgery, and the labial thickness of the hard tissue (LT) was assessed at 0-5 mm apical to the implant shoulder (LT0-LT5) at each time point. A total of 26 patients were included in this study. After wound closure, the test group showed significantly greater thickness in LT0-LT2 than the control group (LT0: test: 4.31 ± 0.73 mm, control: 2.99 ± 1.02 mm; LT1: test: 4.55 ± 0.69 mm, control: 3.60 ± 0.96 mm; LT2: test: 4.76 ± 0.54 mm, control: 4.05 ± 1.01 mm; p < 0.05). At 6 months, significant differences in LT0-LT1 were detected between the groups (LT0: test: 1.88 ± 0.57 mm, control: 1.08 ± 0.60 mm; LT1: test: 2.36 ± 0.66 mm, control: 1.69 ± 0.58 mm; p < 0.05). Within the limitations of this study, the use of digital workflow in GBR with particulate bone substitutes and i-PRF exerted a positive effect on the labial thickness of hard tissue in the coronal portion of the implant after wound closure and at 6 months.

Graphene Oxide Nanosheets with Efficient Antibacterial Activity Against Methicillin-Resistant Staphylococcus aureus (MRSA).

The development of drug-resistant bacteria has become a public health problem, among which methicillin-resistant Staphylococcus aureus (MRSA) leads to various life-threatening diseases. Graphene oxide (GO) is a two-dimensional nanomaterial with potential in the anti-MRSA treatment. This study prepared GO nanosheets with fixed lamellar size, investigated its antibacterial activity against MRSA, and analyzed the related antibacterial mechanisms. We found that the fabrication of GO with stable dispersion was workable. Furthermore, such GO had superior antibacterial performance against MRSA at low concentrations with the dose-dependent anti-MRSA effect. The GO-MRSA interaction also provided fundamental support for the antibacterial mechanisms with cleavage and encapsulation effects. In conclusion, GO nanosheets may be a promising antimicrobial agent against MRSA.

A Retrospective Study on the Transferring Accuracy of a Fully Guided Digital Template in the Anterior Zone.

The accuracy of implant placement with a fully guided digital template can be influenced by many factors, such as arch difference, alveolar bone density, timing of implant placement and open flap. The purpose of this article was to evaluate the factors presumptively affecting the accuracy of implant placement assisted by the fully guided template in the anterior zone. In 40 patients with missing anterior teeth, a total of 52 implants were placed with tooth-borne, fully guided templates after CBCT evaluation, in West China Hospital of Stomatology, Sichuan University. After overlapping the pre-and post-operative DICOM data, measurements were taken in the dental implant planning software (Nobel Clinician®) to calculate linear and angular deviations between virtual placement plan and actual implant placement. Grouping was categorized according to three factors that possibly have an influence on accuracy: arch type (maxilla/mandible), timing of implant placement (immediate/delayed), surgical technique (open flap/flapless). The data was analyzed with independent sample t-test (p < 0.05). The results showed that the apical, coronal, depth and angular mean deviations of implant positions in anterior zone were 1.13 ± 0.39 mm, 0.86 ± 0.33 mm, 0.41 ± 0.66 mm, 3.32 ± 1.65° with the fully guided templates. The accuracy at apex level, coronal level and the angulation were similar between the maxilla and mandible, and the magnitude of all four deviations between immediate and delayed implantation, open flap and flapless technique were small. No statistically significant difference was observed (p > 0.05). Whereas there was significant difference in depth deviation between maxilla and mandible (p < 0.05). Conclusively, the implant site, alveolar bone density, timing of implant placement and surgical techniques merely compromise the implant placement accuracy under the assistance of a fully guided template.

Evaluation of Immediate Implantation and Provisionalization Combined with Guided Bone Regeneration by a Flap Approach in the Maxillary Esthetic Zone: A Retrospective Controlled Study.

The aim of this research was too compare the thickness change of labial contour and bone tissues, as well as some biological complications of immediate implantation with and without immediate provisionalization for a single anterior maxilla presenting a vertical defect on labial bone with the need of guided bone regeneration (GBR) by a flap approach. A total of 40 single implants were placed in 40 patients into fresh extraction sockets of the anterior maxilla with a vertical defect on the labial bone (<4 mm). Simultaneously, GBR was conducted at the sites by a flap approach, and the implants were given immediate or delayed provisionalization. The thickness change of bone tissues during six-month evaluation and labial contour during three and six-month follow-up were measured. Complications such as implant and restoration survival rates, infection as well as wound exposure were also evaluated at six months postoperatively. After six months, the mean thickness losses in labial bone were 0.9040, 0.8050, 0.7165, 0.5285 and 0.5335 mm at five different sites in immediate provisionalization group, and 0.8780, 0.8605, 0.7560, 0.5900 and 0.6300 mm, respectively, in delayed provisionalization group, showing no significant difference between the groups at all measurement sites. Although the labial contour changes of the two groups were similar at most sites, the values at 1 and 2 mm above the implant neck remained significantly lower in the immediate provisionalization group at three and six months postoperatively. No complications occurred during the follow-up time. Based on the limitation of this study, the immediate implantation combined with GBR, flap operation and immediate provisionalization obtained acceptable outcomes for a single anterior maxilla with vertical defect on the labial bone, but more long-term research with a larger sample are urgently needed in the future.

Applications of Hydrogel with Special Physical Properties in Bone and Cartilage Regeneration.

Hydrogel is a polymer matrix containing a large amount of water. It is similar to extracellular matrix components. It comes into contact with blood, body fluids, and human tissues without affecting the metabolism of organisms. It can be applied to bone and cartilage tissues. This article introduces the high-strength polymer hydrogel and its modification methods to adapt to the field of bone and cartilage tissue engineering. From the perspective of the mechanical properties of hydrogels, the mechanical strength of hydrogels has experienced from the weak-strength traditional hydrogels to the high-strength hydrogels, then the injectable hydrogels were invented and realized the purpose of good fluidity before the use of hydrogels and high strength in the later period. In addition, specific methods to give special physical properties to the hydrogel used in the field of bone and cartilage tissue engineering will also be discussed, such as 3D printing, integrated repair of bone and cartilage tissue, bone vascularization, and osteogenesis hydrogels that regulate cell growth, antibacterial properties, and repeatable viscosity in humid environments. Finally, we explain the main reasons and contradictions in current applications, look forward to the research prospects in the field of bone and cartilage tissue engineering, and emphasize the importance of conducting research in this field to promote medical progress.

The Influence of Different Guided Bone Regeneration Procedures on the Contour of Bone Graft after Wound Closure: A Retrospective Cohort Study.

The aim of this study was to evaluate the impact of different guided bone regeneration (GBR) procedures on bone graft contour after wound closure in lateral ridge augmentation. A total of 48 patients with 63 augmented sites were included in this study. Participants were divided into 4 groups (n = 12 in each group) based on different surgical procedures: group 1: particulate bone substitute + collagen membrane; group 2: particulate bone substitute + collagen membrane + healing cap, group 3: particulate bone substitute + injectable platelet-rich fibrin (i-PRF) + collagen membrane; group 4: particulate bone substitute + i-PRF + surgical template + collagen membrane. After wound closure, the thickness of labial graft was measured at 0-5 mm apical to the implant shoulder (T0-T5). At T0-T2, the thickness of labial graft in group 4 was significantly higher than the other three groups (p < 0.05). And group 4 showed significantly more labial graft thickness than group 1 and group 2 at T3-T5 (p < 0.05). Within the limitations of this study, the use of i-PRF in combination with the surgical template in GBR may contribute to achieving an appropriate bone graft contour after wound closure.