In an effort to prepare non-autologous bone graft or biomaterial that would possess characteristics comparable to autologous bone, many different allogenic bone derivatives have been created. Although different existing processing methods aim to achieve the very same results, the specific parameters applied during different stages material preparation can result in significant differences in the material’s mechanical and biological properties The properties, including osteoconductive, osteoinductive, and even osteogenic potential, can differ vastly depending on particular preparation and storage techniques used. Osteogenic properties, which have long been thought to be characteristic to autogenic bone grafts only, now seem to also be achievable in allogenic materials due to the possibility to seed the host’s stem cells on a graft before its implantation. In this article, we aim to review the available literature on allogenic bone and its derivatives as well as the influence of different preparation methods on its performance.
Titanium currently has a well-established position as the gold standard for manufacturing dental implants; however, it is not free of flaws. Mentions of possible soft-tissue discoloration, corrosion, and possible allergic reactions have led to the development of zirconia dental implants. Various techniques for the surface modification of titanium have been applied to increase titanium implants’ ability to osseointegrate. Similarly, to achieve the best possible results, zirconia dental implants have also had their surface modified to promote proper healing and satisfactory long-term results. Despite zirconium oxide being a ceramic material, not simply a metal, there have been mentions of it being susceptible to corrosion too. In this article, we aim to review the literature available on zirconia implants, the available techniques for the surface modification of zirconia, and the effects of these techniques on zirconia’s biological properties. Zirconia’s biocompatibility and ability to osseointegrate appears unquestionably good. Despite some of its mechanical properties being, factually, inferior to those of titanium, the benefits seem to outweigh the drawbacks. Zirconia implants show very good success rates in clinical research. This is partially due to available methods of surface treatment, including nanotopography alterations, which allow for improved wettability, bone-to-implant contact, and osteointegration in general.
8 February 2023 in Advances in Clinical and Experimental Medicine
Three-dimensional bioprinting technology appears to be a promising solution for the treatment and reconstruction of a wide range of maxillofacial bone defects. In this review, the authors discuss different bioprinting solutions and options in the context of the 4 factors of bone healing: structures or scaffolds, osteogenic cells, growth factors, and stabilization (diamond concept of healing), as well as the influence of a 5th factor - vascularization. Bone is a complex tissue; hence, bone bioprinting may require different technical approaches and mixed methods. Ultraviolet (UV) crosslinkable hydrogels, such as gelatin methacryloyl (GelMA), are among the most promising bioinks; they are enhanced by hydroxyapatite or 1-2.5 mm beta-tricalcium phosphate (β-TCP) granules and porous scaffolds with recommended pore sizes greater than 300 μm. The advantages of mesenchymal stem cells (MSCs) are their significant availability, low tumorigenicity, and great potential for differentiation into osteoblasts or endothelial cells (ECs). Although growth factors require advanced delivery systems, they provide excellent improvement in the functionality of printed tissues. A proper vasculature system supplies cells with oxygen and nutrients, removes waste products, promotes osteogenesis, prevents ischemic necrosis, and improves the mechanical properties of bone. With all of these aspects perfectly balanced and working in synergy, the clinical use of bioprinting is only a matter of time.
Background: Atrophy of the alveolar ridge in the posterior maxilla often requires sinus floor elevation prior to implant placement. Photobiomodulation using low-level laser therapy (LLLT) has been suggested as a supportive approach for bone healing, although data based on histological evaluation are still limited. Methods: This study presents histological and radiological secondary outcomes of a randomized clinical trial on bone regeneration after lateral window sinus augmentation. Twenty patients were allocated according to grafting material (allogeneic or xenogeneic) and the use of adjunctive LLLT. After 6 months, bone core biopsies were obtained at the time of implant placement and processed for histological analysis. Radiological bone gain was assessed using CBCT. Results: Bone gain was achieved in all groups, allowing implant placement in every case. Mean bone gain reached 7.53 ± 3.32 mm in LLLT-treated sites and 7.02 ± 2.00 mm in controls, with no statistically significant differences. Histological analysis confirmed trabecular bone formation across all groups. Mild inflammatory cell infiltrates were observed more frequently in LLLT-treated sites (p = 0.029), although this finding was not associated with impaired tissue organization or compromised healing. Conclusions: Both allogeneic and xenogeneic grafts showed good biocompatibility and supported effective bone regeneration after sinus augmentation. The addition of photobiomodulation did not demonstrate statistically significant clinical or radiological benefits within this exploratory cohort, but it may be associated with subtle differences in tissue remodeling.
Titanium dental implants are widely regarded as the gold standard for the rehabilitation of missing teeth due to their high survival rates and favorable mechanical properties. However, in the oral environment, implant materials are continuously exposed to complex chemical, mechanical, and biological factors that may lead to surface degradation, including corrosion, tribocorrosion, and mechanical wear. These processes can alter implant surface characteristics and influence biological responses in peri-implant tissues. Zirconia implants have been introduced as alternative material due to their favorable aesthetics and biocompatibility. Nevertheless, zirconia ceramics are also susceptible to degradation phenomena, including hydrothermal aging, phase transformation, and surface wear under specific conditions, although their clinical relevance remains unclear. In addition, emerging hybrid titanium–zirconia implant systems introduce new considerations regarding surface stability. This scoping review, conducted in accordance with PRISMA-ScR guidelines, summarizes the current evidence on degradation mechanisms affecting titanium, zirconia, and hybrid dental implants, with particular focus on processes occurring in the oral environment and their biological and clinical implications. The available evidence differs substantially between the two materials. While titanium degradation is well documented and supported by both experimental and clinical studies, the evidence for a hybrid implant remains limited and is largely based on in vitro and mechanistic data.
(1) Background: The role of baseline humoral immunization in bone regeneration remains unclear. This study assessed the relationship between baseline serological immunization, graft type, photobiomodulation (PBM), and histological outcomes after maxillary sinus floor augmentation. (2) Methods: This exploratory secondary analysis included 20 adults undergoing lateral maxillary sinus lifting. Patients were allocated according to graft type (allogeneic or xenogeneic) and postoperative protocol (with or without adjunctive PBM). Before surgery, serum samples were analyzed for anti-HLA class I, anti-HLA class II, and anti-MICA antibodies. After approximately 6 months, bone core biopsies were collected. Histological evaluation focused on inflammatory cell infiltrates (ICI). (3) Results: Baseline antibody positivity was detected in 35.0% of patients for anti-HLA class I, 55.0% for anti-HLA class II, and 45.0% for anti-MICA. Histological findings were generally favorable. ICI scores were low, with 65.0% of samples scoring 0 and 35.0% scoring 1. A nominal positive correlation was observed between anti-HLA class I NBG ratio and ICI; however, this finding did not remain statistically significant after correction for multiple comparisons. Exploratory PBM subgroup estimates were directionally different but were based on very small subgroups and should not be interpreted as evidence of effect modification. (4) Conclusions: The findings suggest a possible hypothesis-generating link between baseline humoral sensitization and mild local inflammatory infiltrates, which requires validation in larger, prospectively powered studies with predefined histological and immunological endpoints.