Long-term reliable physical health monitoring by sweat pore-inspired perforated electronic skins.

Electronic skins (e-skins)-electronic sensors mechanically compliant to human skin-have long been developed as an ideal electronic platform for noninvasive human health monitoring. For reliable physical health monitoring, the interface between the e-skin and human skin must be conformal and intact consistently. However, conventional e-skins cannot perfectly permeate sweat in normal day-to-day activities, resulting in degradation of the intimate interface over time and impeding stable physical sensing. Here, we present a sweat pore-inspired perforated e-skin that can effectively suppress sweat accumulation and allow inorganic sensors to obtain physical health information without malfunctioning. The auxetic dumbbell through-hole patterns in perforated e-skins lead to synergistic effects on physical properties including mechanical reliability, conformability, areal mass density, and adhesion to the skin. The perforated e-skin allows one to laminate onto the skin with consistent homeostasis, enabling multiple inorganic sensors on the skin to reliably monitor the wearer's health over a period of weeks.

Assessment of Compatibility between Various Intraoral Scanners and 3D Printers through an Accuracy Analysis of 3D Printed Models.

To assess the accuracy of various intraoral scanners (IOSs) and to investigate the existence of mutual compatibility that affects the accuracy between IOS and 3-dimensional (3D) printing using a scan quadrant model. For clinical implication, crown preparations and cavity design according to prosthetic diagnosis and treatment considerations must be acquired by a digital scanner. The selected typodont model was scanned using a reference scanner, from which reference (Ref) standard tessellation language (STL) data were created. Data obtained by scanning the typodont model with IOSs based on three different technologies were divided into three groups (CS3600, i500, and Trios3). Scanned data from the groups were divided into sub-groups of digital light processing (DLP), fused deposition modeling (FDM), and stereolithography apparatus (SLA), based on which 3D printed models (3DP) were fabricated. The 3DP dental models were scanned to obtain a total of 90 3DP STL datasets. The best-fit algorithm of 3D analysis software was used for teeth and arch measurements, while trueness was analyzed by calculating the average deviation among measured values based on superimposition of Ref and IOS and 3DP data. The differences between Ref and IOS (Ref-IOS), Ref and 3DP (Ref-IOS/3DP), and IOS and 3DP data (IOS-3DP) were compared and analyzed, while accuracy within each of the three main groups was assessed. For statistical analysis, the Kruskal-Wallis, Mann-Whitney U, and repeated measures ANOVA test were used (p < 0.05). The major finding is that the mutual relationships between IOSs and 3D printers vary depending on the combination. However, i500 intraoral scanner and DLP 3D printer was the combination that showed the best trueness value.

Assessment of metal sleeve-free 3D-printed implant surgical guides.

OBJECTIVES: The aim of the present study was to investigate the adaptation and guide hole tolerance of metal sleeve-free computer-assisted implant surgical guides fabricated with 3D printers. METHODS: An implant surgical guide for full-guided implant placement was designed with a total of eight different guide holes. Ten implant surgical guides (n=10) were fabricated from the same design with each of five in-office 3D printers (D1, FOR, ONE, PER, and ZEN) using compatible printing materials. Ten surgical guides fabricated by the manufacturer of the implant company were used as the control group (CON). The adaptation of the surgical guides was evaluated by the replica technique. The tolerance of the guide holes was evaluated by measuring the degree of diversion with guide drills. RESULTS: CON and D1 showed superior internal adaptation with a gap distance of less than 1mm. The mean degree of diversion of the guide holes ranged from 3.45° for ZEN to 6.55° for PER. The tolerances of CON (4.70°) and D1 (4.50°) did not differ at the level of statistical significance at α=0.05. SIGNIFICANCE: The characteristics of implant surgical guides were evaluated per se. None of the 3D printers fabricated superior implant surgical guides to those produced by the manufacturer with regard to the internal fit and guide tolerance. However, the potential for the routine clinical use of in-office 3D printers was demonstrated. Further studies are required to determine how the guide hole tolerance and the angular deviation between the preplanned and actual implant positions are related.