OBJECTIVE: To assess the clinical and radiographic outcomes of alveolar ridge augmentation using a novel three-dimensional printed individualized titanium mesh (3D-PITM) for guided bone regeneration (GBR).
METHODS: Preoperative cone-beam computed tomography (CBCT) was used to evaluate alveolar ridge defects, followed by augmentation with high-porosity 3D-PITM featuring circular and spindle-shaped pores. Postoperative CBCT scans were taken immediately and after 6 months of healing. These scans were compared with preoperative scans to calculate changes in bone volume, height, and width, along with the corresponding resorption rates. A statistical analysis of the results was then conducted.
RESULTS: A total of 21 patients participated in the study, involving alveolar ridge augmentation at 38 implant sites. After 6 months of healing, the average bone augmentation volume of 21 patients remained at 489.71 ± 252.53 mm3, with a resorption rate of 16.05% ± 8.07%. For 38 implant sites, the average vertical bone increment was 3.63 ± 2.29 mm, with a resorption rate of 17.55% ± 15.10%. The horizontal bone increment at the designed implant platform was 4.43 ± 1.85 mm, with a resorption rate of 25.26% ± 15.73%. The horizontal bone increment 2 mm below the platform was 5.50 ± 2.48 mm, with a resorption rate of 16.03% ± 9.57%. The main complication was exposure to 3D-PITM, which occurred at a rate of 15.79%.
CONCLUSIONS: The novel 3D-PITM used in GBR resulted in predictable bone augmentation. Moderate over-augmentation in the design, proper soft tissue management, and rigorous follow-ups are beneficial for reducing the graft resorption and the incidence of exposure.

Background: The aim of this study was to retrospectively evaluate the 3-year radiographic outcomes of periodontal intrabony defects treated with non-surgical subgingival therapy (NST), assessing radiographic bone gain (RBG) through experimental digital software, named \"Bone Defect Analysis (BDA)\". Methods: The study included 17 intrabony defects in 14 patients. BDA software (version 1) was used on radiographs to calculate RBG (in %) and variations in defect angle (in °) between baseline (T0) and 3-year follow-up (T1). Soft tissue conditions were registered, reporting bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL). Defects were analyzed according to angles less (group A) or greater (group B) than 30°. Results: Nine and eight defects were, respectively, analyzed in groups A and B. Three years after treatment, an average RBG of 12.28% was found overall, with 13.25% and 10.11% for groups A and B, respectively (p = 0.28). Clinically, a mean CAL of 6.05 mm at T1 (from 10.94 mm at T0) was found, with 6.88 mm and 5.12 mm in groups A and B, respectively (p = 0.07). Conclusions: BDA software demonstrated predictability in the evaluation of bone variations after NST, revealing better clinical findings for intrabony defects with an initial smaller angle.

Piezoelectric effect produces an electrical signal when stress is applied to the bone. When the integrity of the bone is destroyed, the biopotential within the defect site is reduced and several physiological responses are initiated to facilitate healing. During the healing of the bone defect, the bioelectric potential returns to normal levels. Treatment of fractures that exceed innate regenerative capacity or exhibit delayed healing requires surgical intervention for bone reconstruction. For bone defects that cannot heal on their own, exogenous electric fields are used to assist in treatment. This paper reviews the effects of exogenous electrical stimulation on bone healing, including osteogenesis, angiogenesis, reduction in inflammation and effects on the peripheral nervous system. This paper also reviews novel electrical stimulation methods, such as small power supplies and nanogenerators, that have emerged in recent years. Finally, the challenges and future trends of using electrical stimulation therapy for accelerating bone healing are discussed.

The reconstruction of long bone defects as a result of primary traumatic, secondary infection or tumor-related loss of substance continues to represent a surgical challenge. Callus distraction via segment transport, vascularized bone transfer and the induced membrane technique (IMT) are established methods of reconstruction. In recent decades IMT has experienced increasing popularity due to its practicability, reproducibility and reliability. At the same time, the original technique has undergone numerous modifications. The results are correspondingly heterogeneous. This overview is intended to explain the basic principles of IMT and to provide an overview of the various modifications and their complications.
UNASSIGNED: Die Rekonstruktion langstreckiger Knochendefekte infolge von primär traumatischen oder sekundär infektions- oder tumorbedingten Substanzverlusten stellt nach wie vor eine chirurgische Herausforderung dar. Die Kallusdistraktion über Segmenttransport, der vaskularisierte Knochentransfer und die induzierte Membrantechnik (IMT) stellen etablierte Verfahren der Rekonstruktion dar. In den letzten Jahrzehnten erfreut sich die IMT aufgrund ihrer Praktikabilität, Reproduzierbarkeit und Zuverlässigkeit zunehmender Popularität. Gleichsam erfuhr die Originaltechnik eine Vielzahl von Modifikationen. Die Ergebnisse stellen sich als entsprechend heterogen dar. Diese Übersicht soll die wesentlichen Grundprinzipien der IMT darlegen und einen Überblick über die verschiedenen Modifikationen und ihre Komplikationen geben.

Severe bone defects pose a clinical challenge in total ankle arthroplasty (TAA) and are frequently considered contraindicated. We introduce an innovative approach that utilizes a structural tibial cut autograft to address anterior distal tibia bone defects during TAA. This technique is a viable alternative to employing revision TAA systems or resorting to excessively high tibial cuts. Furthermore, it facilitates achieving favorable sagittal alignment and ensures adequate fixation strength of the tibial component.

Conventional bone scaffolds, which are mainly ascribed to highly active osteoclasts and an inflammatory microenvironment with high levels of reactive oxygen species and pro-inflammatory factors, barely satisfy osteoporotic defect repair. Herein, multifunctional self-assembled supramolecular fiber hydrogels (Ce-Aln gel) consisting of alendronate (Aln) and cerium (Ce) ions were constructed for osteoporotic bone defect repair. Based on the reversible interaction and polyvalent cerium ions, the Ce-Aln gel, which was mainly composed of ionic coordination and hydrogen bonds, displayed good injectability and autocatalytic amplification of the antioxidant effect. In vitro studies showed that the Ce-Aln gel effectively maintained the biological function of osteoblasts by regulating redox homeostasis and improved the inflammatory microenvironment to enhance the inhibitory effect on osteoclasts. Ribonucleic acid (RNA) sequencing further revealed significant downregulation of various metabolic pathways, including apoptosis signaling, hypoxia metabolism and tumor necrosis factor-alpha (TNF-α) signaling via the nuclear factor kappa-B pathway after treatment with the Ce-Aln gel. In vivo experiments showed that the clinical drug-based Ce-Aln gel effectively promoted the tissue repair of osteoporotic bone defects by improving inflammation and inhibiting osteoclast formation at the defect. Notably, in vivo systemic osteoporosis was significantly ameliorated, highlighting the strong potential of clinical translation for precise therapy of bone defects.

Bone defects caused by trauma, tumor resection, and infections are significant clinical challenges. Excessive reactive oxygen species (ROS) usually accumulate in the defect area, which may impair the function of cells involved in bone formation, posing a serious challenge for bone repair. Due to the potent ROS scavenging ability, as well as potential anti-inflammatory and immunomodulatory activities, antioxidants play an indispensable role in the maintenance and protection of bone health and have gained increasing attention in recent years. This narrative review aims to give an overview of the main research directions on the application of antioxidant compounds in bone defect repair over the past decade. In addition, the positive effects of various antioxidants and their biomaterial delivery systems in bone repair are summarized to provide new insights for exploring antioxidant-based strategies for bone defect repair.

Irregular bone defects caused by trauma and bone diseases provide a complex implant environment for surgery. Traditional implants often fail to integrate well with the surrounding bone defect interface, therefore, developing an artificial bone scaffold that can adapt to irregular bone defect boundaries is of significant importance for bone defect repair. This study successfully utilized a shape memory ternary copolymer polylactic acid-trimethylene carbonate-hydroxyacetic acid (PLLA-TMC-GA) and dopamine-modified nano-hydroxyapatite (PHA) composite to construct a temperature-responsive bone repair scaffold (PTG/PHA), thereby enhancing the interface compatibility between the implant and the surrounding environment. The addition of PHA has effectively improved the hydrophilicity of the stent and significantly increased its mechanical strength. Furthermore, the Sodium alginate (SA) hydrogel loaded with Icariin (Ica) coated on the stent surface promotes the growth and differentiation of bone cells through the drug-scaffold synergistic effect. Both in vivo and in vitro experiments have shown that the synergistic effect of the composite stent with Icariin significantly enhances the repair of bone defects. This study provides a promising tissue engineering method for the repair of irregular bone defects.

Currently, there are still great challenges in promoting bone defect healing, a common health problem affecting millions of people. Herein an osteoimmunity-regulating biopatch capable of promoting stem cell-based therapies for bone regeneration is developed. A totally biodegradable conjugate is first synthesized, which can self-assemble into bioactive nano micelles (PPT NMs). This nanotherapy effectively improves the osteogenesis of periodontal ligament stem cells (PDLSCs) under pathological conditions, by simultaneously regulating IL-17 signaling and ferroptosis pathways. Incorporation of PPT NMs into biodegradable electrospun nanofibers affords a bioactive patch, which notably improves bone formation in two rat bone defect models. A Janus bio patch is then engineered by integrating the bioactive patch with a stem cell sheet of PDLSCs. The obtained biopatch shows additionally potentiated bone regeneration capacity, by synergistically regulating osteoimmune microenvironment and facilitating stem cell differentiation. Further surface functionalization of the biopatch with tannic acid considerably increases its adhesion to the bone defect, prolongs local retention, and sustains bioactivities, thereby offering much better repair effects in rats with mandibular or cranial bone defects. Moreover, the engineered bioactive patches display good safety. Besides bone defects, this osteoimmunity-regulating biopatch strategy can be applied to promote stem cell therapies for spinal cord injury, wound healing, and skin burns.

Osteoporotic bone defects are serious medical problems due to their sparse bone structure, difficulty in restoration and reconstruction, and high recurrence rates, which also result in heavy economic and social burdens. Herein, we developed a hierarchical hydrogel composed of alendronate sodium (AS)/Mg2+-loaded inverse opal methylpropenylated gelatin (GelMA) hydrogel microspheres (IOHM-AS-Mgs) within methylpropenylated poly(hyaluronic acid) (HAMA) for osteoporotic bone defect treatment. The IOHM-AS-Mgs displayed good cytocompatibility and cell adhesion and strongly stimulated osteogenesis at the transcriptomic and protein levels. When this treatment was applied to the osteoporotic bone defect area, HAMA was used to fix the microspheres. The results of the microcomputed tomography (micro-CT) and histological analyses indicated that the hierarchical hydrogel had the best therapeutic effect. Therefore, this hydrogel is a new candidate for osteoporotic bone defect treatment.