Objectives: To evaluate the accuracy of virtual orthodontic setup in simulating treatment outcomes and to determine whether virtual setup should be used in orthodontic practice and education. Materials and Methods: A systematic search was performed in five electronic databases: PubMed, Scopus, Embase, ProQuest Dissertations & Theses Global, and Google Scholar from January 2000 to November 2022 to identify all potentially relevant evidence. The reference lists of identified articles were also screened for relevant literature. The last search was conducted on 30 November 2022. Results: This systematic review included twenty-one articles, where all of them were assessed as moderate risk of bias. The extracted data were categorized into three groups, which were: (1) Virtual setup and manual setup; (2) Virtual setup and actual outcomes in clear aligner treatment; (3) Virtual setup and actual outcomes in fixed appliance treatment. There appeared to be statistically significant differences between virtual setups and actual treatment outcomes, however the discrepancies were clinically acceptable. Conclusion: This systematic review supports the use of orthodontic virtual setups, and therefore they should be implemented in orthodontic practice and education with clinically acceptable accuracy. However, high-quality research should be required to confirm the accuracy of virtual setups in simulating treatment outcomes.

The aim of this work was to study the accuracy of the intraoral scanner for detection of tooth wear in natural teeth by using micro-computed tomography (micro-CT) as a gold standard. Twenty premolars were prepared, fixed in acrylic blocks, and scanned with an intraoral scanner (iTero Element® 2) and micro-CT for baseline reference images before artificial tooth wear induction. The samples were then scrubbed with abrasive sandpaper 20 times and scanned with the intraoral scanner. They were then superimposed with the reference images utilising the “TimeLapse” feature of the scanner until the abraded area appeared yellow, indicating tooth surface loss in the 50-200 μm range. The same samples were then rescanned by micro-CT to measure the actual tooth surface loss. This procedure was repeated for the subsequent experimental tooth surface loss of 200-400 μm range (orange areas) and 400-750 μm range (red areas). The collected data were analysed for sensitivity, positive predictive value (PPV), and accuracy. Level of statistical significance was set at .05. In the detection of experimental tooth surface loss, the specificity, PPV, and accuracy of the intraoral scanner were 98%, 98%, and 97%, respectively. The iTero® intraoral scanner can be recommended to be a suitable screening tool for tooth wear in routine dental practice.

Introduction: This study investigated the physical, mechanical, and optical properties of 3-dimensional (3D) printing resins compared with thermoplastic materials to evaluate their suitability for the fabrication of orthodontic clear retainers. Methods: Samples were prepared from thermoplastic sheets (Duran [ScheuDental GmbH, Iserlohn, Germany] and Zendura [Bay Materials LLC, Fremont, Calif]) and biocompatible 3D- printing resins (Dental LT Clear V2 [Formlabs Inc, Somerville, Mass] and OrthoFlex [Nextdent BV, Soesterberg, The Netherlands]) according to the manufacturer's instructions. The materials were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and water sorption tests. Mechanical properties were assessed by tensile tests and hardness under 3 different conditions: dry, wet (24-hour water immersion), and aged (thermocyled for 10,000 cycles). Surface characteristics were qualitatively and quantitatively evaluated by scanning electron microscopy and 3D confocal imaging, respectively. Optical properties were assessed by ultraviolet-visible spectroscopy and color stability tests by immersion into various staining solutions. Results: The mechanical properties of the 3D-printing resins were more markedly altered in different testing conditions (dry, wet, and aged) than in thermoplastic materials. The surface roughness, transparency, and color stability of 3D-printing resins are significantly inferior, especially NextDent OrthoFlex. Conclusions: The evaluated 3D-printing resins are more brittle and less ductile compared with the thermoplastic materials. The 3D-printing resins also do not meet the clinical thresholds of surface roughness and optical properties for the fabrication of orthodontic clear retainers. Further post- processing of the 3D-printing resins may be required to improve these properties. (Am J Orthod Dentofacial Orthop 2025;167:95-109)

Objectives: To address the high surface roughness and poor optical properties of three-dimensional (3D) printed orthodontic clear retainers, an alternative post-processing protocol was investigated with the goal of achieving improved surface, optical, and mechanical properties while preserving dimensional accuracy. Materials and methods: Samples were prepared from two biocompatible methacrylate-based 3D-printing resins (Formlabs Dental LT Clear V2, NextDent OrthoFlex) and one thermoplastic material (Duran). For the 3D-printed resins, one group was post-processed by rinsing in isopropyl alcohol, while another group was centrifuged before post-curing in glycerine. Three different testing conditions were used: dry, wet (24-h water immersion), and aged (thermocycling for 10,000 cycles). Surface characteristics were evaluated qualitatively and quantitatively. Optical properties were assessed for transparency and colour stability, while mechanical properties were elicited from tensile and microhardness tests. Water sorption and solubility were calculated. Samples mounted on a dental model were scanned by micro-computed tomography to measure thickness and gap width. Results: 3D-printed samples post-processed by centrifugation showed significantly decreased surface roughness and improved visible light transmission, colour stability, tensile strength, and hardness. The centrifuged samples showed significantly increased thickness, while designing an offset equal to this thickness improved the adaptation. Conclusions: Post-processing by centrifugation produces surface coating that enhances the surface and optical properties of the 3D-printed orthodontic retainers, while curing in an oxygen-free environment improves their mechanical properties. Design modifications may be necessary for this protocol to ensure proper adaptation to the dentition. Clinical relevance: Proper design and post-processing protocols are necessary to achieve the desired properties of orthodontic clear retainers.

Objective: To evaluate educational impact of game-based learning (GBL) in orthodontic education. Methods: A systematic search was undertaken across four databases (Scopus, PubMed, ProQuest Dissertations & Theses Global, and Google Scholar) to identify relevant articles published from January 2000 to December 2023. Additionally, the reference lists of identified literature were examined to further search for relevant literature. The last search was performed on 28 January 2024. Results: Following the article selection process, seven articles were included in this systematic review, comprising four randomized control trials and three questionnaire surveys. Six articles were assessed to have a moderate risk of biases, whereas one research exhibited a low risk of bias. GBL interventions assessed in five articles were designed in digital format, while one study implemented evaluated traditional learning, and another employed a card game format. Two RCTs indicated a greater effectiveness of GBL in enhancing learner performance compared to traditional learning methods, while one article found no significant difference. Across all articles, positive perceptions of GBL were consistently highlighted at both undergraduate and postgraduate levels. Conclusion: This systematic review supports the potential of GBL in orthodontic education. The implementation of GBL is recommended to integrate entertaining and educational elements, fostering learner performance within engaging learning environments. However, it is imperative to acknowledge that the overall quality of evidence is limited, primarily due to the moderate risk of biases identified in six of the included articles. Consequently, further high-quality experimental studies are required to validate the effectiveness of GBL in orthodontic education.

Nickel-Titanium (NiTi) springs have been increasingly used in orthodontics; however, no optimum condition of heat treatment has been reported. Therefore, this research was conducted to determine the optimum heat-treatment temperature and duration for the fabrication of NiTi-closed coil springs by investigating their effects on thermo-mechanical properties. As-drawn straight NiTi wires of 0.2 mm diameter were used to fabricate closed coil springs of 0.9 mm lumen diameter. The springs were heat-treated at three different temperatures (400, 450, and 500 °C) with three different durations (20, 40, and 60 min). Electron Probe Micro-Analysis (EPMA) and Differential Scanning Calorimetry (DSC) were used to investigate element composition and thermo-mechanical properties, respectively. Custom-made NiTi closed coil springs composed of 49.41%-Ti and 50.57%-Ni by atomic weight, where their DSC curves of 500 °C presented the obvious endothermic and exothermic peaks, and the austenite finish temperature (A_f) were approximately 25 °C. With increasing temperature, deactivation curves presented decreased plateau slopes generating higher superelastic ratios (SE ratios). At 500 °C, closed coil springs showed superelastic tendency with lower stress hysteresis. The thermo-mechanical properties were significantly influenced by heat-treatment temperature rather than duration. The optimum parameter appeared to be 500 °C for 40 min to produce appropriate force delivery levels, relatively low plateau slope, and lower hysteresis for orthodontic use.