A wide range of materials has been considered to repair cranial defects. In the field of cranioplasty, poly(methyl methacrylate) (PMMA)-based bone cements and modifications through the inclusion of copper doped tricalcium phosphate (Cu-TCP) particles have been already investigated. On the other hand, aliphatic polyesters such as poly(ε-caprolactone) (PCL) and polylactic acid (PLA) have been frequently investigated to make scaffolds for cranial bone regeneration. Accordingly, the aim of the current research was to design and fabricate customized hybrid devices for the repair of large cranial defects integrating the reverse engineering approach with additive manufacturing, The hybrid device consisted of a 3D additive manufactured polyester porous structures infiltrated with PMMA/Cu-TCP (97.5/2.5 w/w) bone cement. Temperature profiles were first evaluated for 3D hybrid devices (PCL/PMMA, PLA/PMMA, PCL/PMMA/Cu-TCP and PLA/PMMA/Cu-TCP). Peak temperatures recorded for hybrid PCL/PMMA and PCL/PMMA/Cu-TCP were significantly lower than those found for the PLA-based ones. Virtual and physical models of customized devices for large cranial defect were developed to assess the feasibility of the proposed technical solutions. A theoretical analysis was preliminarily performed on the entire head model trying to simulate severe impact conditions for people with the customized hybrid device (PCL/PMMA/Cu-TCP) (i.e., a rigid sphere impacting the implant region of the head). Results from finite element analysis (FEA) provided information on the different components of the model.

The growing importance of state assessments in civil engineering has led to intensive research into the development of damage identification methods based on vibrations. Natural frequencies and modal shapes have garnered great interest because modal parameters are invariant of structure. Moreover, thanks to the global nature of modal parameters, their variations are not limited to the location of the damage. This is an important advantage that offers the opportunity to identify damage with sensors whose position does not have to coincide with the damaged area. The integration of MEMS sensors into structural health monitoring (SHM) systems offers a promising approach to long-term structural maintenance, especially in large-scale infrastructure. This paper presents an anomaly detection technique that analyzes raw sequential data within a statistical framework to detect damage that causes prestress loss of the tendon by exploiting a distributed monitoring system composed of six high-performance MEMS sensors. The proposed system is preliminarily evaluated to identify the frequency of the first mode, and then the proposed methodology is validated on acceleration data collected on a 240 cm beam in three different damage configurations, achieving a high detection accuracy and showing that its output can also evaluate the damage localization.

Background and Objectives: To evaluate the influence of proximal box design on primary stability and adhesive bond strength of indirect partial bonded restorations (IPBR) in posterior teeth. Materials and Methods: Thirty extracted human third upper molars were randomly assigned to three groups (n = 10 each): Group A, butt joint overlay-type restorations with proximal box (height-to-depth ratio 1:2–1:3); Group B, proximal box with height-to-depth ratio 1:1; and Group C, flat bevel preparation as control. Specimens underwent standardized preparation: immediate dentin sealing, restoration with overlays, and cementation with Panavia V5 adhesive resin cement. Mechanical measurements were performed to assess the tensile bond strength 48 h post-cementation using a universal testing machine. Finite element analysis (FEA) was also carried out to evaluate stress distribution at the adhesive interface. Data were analyzed by ANOVA with the Bonferroni post hoc tests. Results: Group A exhibited significantly higher bond strength values (403.7 ± 37.5 N) compared with Group B (340.4 ± 32.7 N; p < 0.01) and Group C (324.8 ± 33.3 N; p < 0.01). No significant difference was observed between Groups B and C. FEA corroborated the experimental findings, showing more homogeneous stress distribution for Group A and higher stress concentrations in Groups B and C. Conclusions: Proximal box design significantly affects the primary stability and bond strength of IPBR in vitro. A deeper proximal box with favourable geometric features enhances adhesive performance and stress distribution. Within the limitations of this study, these findings suggest potential clinical benefits, although further in vivo studies under dynamic conditions are needed to confirm long-term restoration performance.