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. Ti3C2 MXene—belonging to a new class of two-dimensional (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, Ti3C2 MXene was incorporated into composite scaffolds composed of hydroxyapatite (HA) and sodium alginate (SA) 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, CCK-8 test, qRT-PCR, ALP activity and ARS tests of BMSCs. A rat calvarial defect model was performed to explore the osteogenic activity of the MXene composite scaffolds in vivo. The results showed the obtained scaffold had a uniform structure, macropore morphology, and high mechanical strength. In vitro experimental results revealed that the scaffold exhibited excellent biocompatibility with bone mesenchymal stem cells, 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-defect in vivo and promoted bone healing to a significantly greater degree than scaffolds without added Ti3C2 MXene did. Conclusively, the Ti3C2 MXene 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.

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.

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

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.