Recent decades clearly demonstrate the growing use of nanomaterials in medical practice, and their effectiveness is systematically confirmed by the consequent scientific research. An example of the use of nanomaterials in dentistry is endodontic treatment, which, due to its specificity, is one of the most demanding procedures, fraught with numerous challenges, such as difficulties in reaching tooth roots and ineffective cleaning or insufficient sealing of root canals, which may lead to re-infection or damage to adjacent structures. The use of nanomaterials has a positive impact on solving these problems, and the combination of biomaterials with nanometric technology makes endodontic treatment more effective, precise and comfortable for patients, which contributes to improving the quality of dental care. Currently, nanomaterials with a high biocompatibility can be used in endodontics as components of irrigation solutions, for rinsing root canals and as drug carriers for intracanal use. Nanomaterials are also components of sealants filling root canals. However, the latest research shows that reducing the size of materials to the “nano” scale significantly affects their basic physicochemical properties, which leads to increased reactivity and the ability to interact at the molecular level. These unique physicochemical properties, which have contributed to the use of nanomaterials in numerous medical-related solutions, raise concerns and provoke discussions about the safety of their use in direct contact with tissues.

Titanium and its alloys are widely used in dental implantology due to their favorable mechanical properties and well-documented long-term clinical performance. Among them, Ti-6Al-4V is particularly common in load-bearing applications. Nevertheless, a growing body of experimental and clinical evidence suggests that Ti-6Al-4V implants cannot be regarded as biologically inert in all patients. Adverse tissue responses, such as impaired healing, chronic peri-implant inflammation, and unexplained implant failure, have been reported even in the absence of classical risk factors, including infection, mechanical overload, or confirmed metal allergy. This critical review challenges the prevailing assumption that these complications are driven primarily by mechanical or immunoallergic mechanisms. Instead, oxidative stress is proposed as a central and unifying factor underlying adverse tissue reactions to Ti-6Al-4V dental implants. Corrosion, tribocorrosion, and mechanical wear lead to the release of titanium-, aluminum-, and vanadium-containing particles and ions, which promote excessive generation of reactive oxygen species at the implant–tissue interface. The resulting redox imbalance disrupts bone remodeling, impairs osteogenic differentiation, and maintains a pro-inflammatory microenvironment. Importantly, pathology arises not merely from increased reactive oxygen species production, but from the failure of local antioxidant defense systems to counteract this burden. Insufficient enzymatic and transcriptional antioxidant responses result in persistent redox imbalance, sustained innate immune activation, and progressive tissue intolerance. Oxidative stress is therefore conceptualized not as a secondary byproduct of inflammation, but as a primary driver of immune dysregulation through chronic macrophage activation and inflammasome signaling. This redox-driven feedback loop amplifies tissue damage and compromises long-term osseointegration independently of classical adaptive immune sensitization. Recognizing oxidative stress as a key determinant of implant–tissue interactions offers a more coherent framework for understanding implant-related complications and underscores the need for redox-aware biomaterial strategies and individualized patient risk assessment.

The aim of this study was to evaluate the effect of different bleaching protocols, including laser-assisted techniques, on the microhardness, surface roughness, and tribological resistance of selected light-cured composites. Three Estelite Universal Flow composites with different flow properties and G-aenial Universal Flo composites were tested. Each group underwent bleaching procedures using Opalescence agents at 10%, 16%, and 40% concentrations, with and without laser activation. Surface microhardness was assessed using the Vickers method, roughness was measured with 3D confocal laser microscopy, and friction coefficients and wear patterns were evaluated using tribological testing. All bleaching protocols resulted in reduced microhardness and increased surface roughness. The most significant changes were observed after treatment with 40% hydrogen peroxide. Laser application, particularly at 16% concentration of carbamide peroxide, helped to partially mitigate these effects in some materials. Bleaching procedures, especially those involving high peroxide concentrations, significantly deteriorated the surface properties of dental composites, which may have clinical implications for the patients.

Titanium is widely recognized for its biocompatibility and utility in maxillofacial and orthopedic surgery; however, its influence on bone remodeling biomarkers remains underexplored. This study investigates the effects of uncoated titanium plates on both the growth factors and diacylglycerols (DAGs) in the periostea of the maxilla and mandible, as DAG signaling is an essential secondary messenger molecule involved in intracellular signaling connected to various growth factors. The study group comprised 20 patients undergoing bimaxillary osteotomies using miniplates and screws made of Ti6Al4V titanium, from whom bone fixations were removed, while the control group included 20 patients operated on for dentofacial deformities (before the insertion of titanium fixations). Diacylglycerol levels in the serum and periosteum were analyzed using tandem mass spectrometry coupled with ultra-high performance liquid chromatography. Growth factors in the periosteum were measured via ELISA with commercially available assay kits. Our findings demonstrate a significant reduction in growth factors, including IGF-1, PDGF, and FGF-23, alongside decreased total DAG levels, suggesting titanium plate stabilization may modulate bone remodeling dynamics. Notably, while overall DAG levels declined, specific DAG species such as C16:0/16:0 and C18:0/18:0 were elevated, whereas polyunsaturated DAGs showed reductions, indicating selective regulation of lipid signaling pathways. Correlation analyses highlighted complex interactions between growth factors and DAGs, with distinct regional differences observed in the mandibular and maxillary periostea. These alterations may result from chronic titanium exposure, potentially inducing a low-grade immune response or modifying the local biochemical environment. This study emphasizes the need for further research into the long-term effects of titanium implants, particularly their influence on lipid metabolism, growth factor dynamics, and bone healing.

Dental resin composites are routinely exposed to chemically aggressive beverages that may compromise long-term functional performance. This study investigated the structure–property–tribology relationships of four restorative composites (Filtek Z250, Filtek Z550, Herculite, and Herculite Ultra) subjected to cyclic immersion in beverages with different pH values. A total of 120 cylindrical specimens (7 mm diameter, 2 mm thickness; n = 5 per material per condition) were fabricated and exposed to mineral water, tea, coffee, Coca-Cola^®, Cola Light^®, and red wine for 28 days under cyclic conditions. Microhardness, surface roughness (Ra), steady-state coefficient of friction (COF), and mass variation were evaluated. All composites exhibited significant microhardness reduction after acidic exposure (p < 0.05), with the greatest decrease observed for Herculite Ultra in red wine (−47.4%) and Coca-Cola^® (−35.3%). Filtek Z250 demonstrated the highest baseline hardness and the lowest degradation susceptibility. Surface roughness changes were formulation-dependent, with Herculite Ultra showing pronounced roughening (ΔRa up to +0.074 µm), whereas Filtek Z550 exhibited erosion-driven smoothing (ΔRa down to −0.068 µm). Tribological behaviour was primarily governed by matrix softening rather than roughness alterations, with softened systems displaying unstable frictional responses (COF range: 0.127–0.697; p < 0.05). The results indicate that polymer matrix stability plays a more critical role in long-term functional performance than surface roughness or mass variation alone. Clinically, frequent exposure to acidic and solvent-containing beverages may accelerate mechanical and tribological degradation of susceptible composite formulations.