Three-body wear of 3D printed temporary materials

ObjectiveThe aim of this study was to investigate the three-body wear of different additively manufactured temporary materials, one temporary PMMA material for CAD/CAM milling and one resin-based composite for direct restorations as a control group by using an ACTA machine.MethodsSpecimens (n = 8) of the 3D printing materials 3Delta temp, NextDent C&B, Freeprint temp were additively manufactured by DLP 3D printer. Postprocessing was carried out according to the manufacturer's specifications. Telio CAD were cut out of blocks, Tetric EvoCeram was applied directly and light cured. Three-body wear was simulated with an ACTA machine. Data were statistically analysed (ANOVA, post hoc test: Tukey, p < 0.05). The worn surfaces of the specimens were examined with a FE-SEM.ResultsThe average mean wear was 50 ± 15 μm for Tetric EvoCeram < 62 ± 4 μm for 3Delta temp < 236 ± 31 μm for Telio CAD < 255 ± 13 μm for NextDent C&B < 257 ± 24 μm for Freeprint temp. After 200,000 cycles, the wear and wear rates for Tetric EvoCeram and 3Delta temp were significantly lower than those for the other materials. SEM revealed that 3Delta temp has a higher filler proportion than the other 3D printing materials but less than Tetric EvoCeram.SignificanceThe filler content influences the wear behaviour of additively manufactured materials as well as dental restorative composite materials. While most 3D printing materials have a low inorganic filler load, which qualifies the materials for temporary use only, one 3D printing material has an optimized composition that would qualify the material for longer clinical service time if wear is considered as the outcome variable.     

Comparison of additive manufactured models of the mandible in accuracy and quality using six different 3D printing systems

The aim of this study was to analyze and compare the accuracy and quality of six 3D printing systems available on the market.Data acquisition was performed with 12 scans of human mandibles using an industrial 3D scanner and saved in STL format. These STL files were printed using six different printing systems. Previously defined distances were measured with a sliding caliper on the 72 printed mandibles. The printed models were then scanned once again. Measurements of volumes and surfaces for the STL files and the printed models were compared. Accuracy and quality were evaluated using industrial software. An analysis of the punctual aberration between the template and the printed model, based on a heat map, was also carried out. Secondary factors, such as costs, production times and expendable materials, were also examined.All printing systems performed well in terms of accuracy and quality for clinical usage. The Formiga P110 and the Form 2 showed the best results for volume, with average aberrations of 0.13 ± 0.23 cm³ and 0.12 ± 0.17 cm³, respectively. Similar results were achieved for the heat map aberration, with values of 0.008 ± 0.11 mm (Formiga P110) and 0.004 ± 0.16 mm (Form 2). Both printers showed no significant difference from the optimal neutral line (Formiga P110, p = 0.15; Form 2, p = 0.60). The cheapest models were produced by the Ultimaker 2+, with an average of 5€ per model, making such desktop printers affordable for rapid prototyping. Meanwhile, advanced printing systems with sterilizable and biocompatible printing materials, such as the Formiga P110 and the Form 2, fulfill the high expectations for maxillofacial surgery.     

The influence of printing angle on color and translucency of 3D printed resins for dental restorations

ObjectivesTo evaluate the influence of printing orientation on color and translucency of 3D printing restorative resins.MethodsFour 3D printing resin systems in the available shades (DFT-Detax Freeprint Temp- A1, A2,A3; FP-Formlabs Permanent Crown- A2,A3,B1,C2; FT- Formlabs Temporary CB- A2,A3,B1,C2; GCT-GC Temporary- Light, Medium) were evaluated. Three samples (10×10×1.2 mm) from each material were printed at two different printing orientations (0° and 90°) and polished to 1.00 ± 0,01 mm of thickness. Spectral reflectance was measured against black background using a calibrated spectroradiometer, CIE D65 standard illuminant and the 45°/0°geometry. Color and translucency differences were evaluated using CIEDE2000 metric (ΔE₀₀) and 50:50% perceptibility (PT₀₀ and TPT₀₀) and acceptability (AT₀₀ and TAT₀₀) thresholds.ResultsIn general, color changes due to printing orientation at (0° and 90°) were mainly produced by ΔL* or ΔC* . ΔE₀₀ were above PT₀₀ for all DFT shades, FP-B1, FP-C2, FT-A2 and FT-B1. Only for DFT-1, ΔE₀₀ was above AT₀₀. ΔRTP₀₀ values were above TPT₀₀ for DFT-A1, DFT-A3, FP-B1 and FT-B1, but lower than TAT₀₀. The direction of the changes in translucency (ΔRTP₀₀) depends on the material and shade.SignificanceThe selection of building orientation (0° and 90°) for the 3D printed resins influence the visual color and translucency and therefore their esthetic appearance. These aspects should be considered when printing dental restorations using the evaluated materials.     

Fracture toughness of conventional,milled and 3D printed denture bases

ObjectivesThe aim of this study was to determine and compare fracture toughness (K_IC) and work of fracture (WOF) of a conventional (C) denture base, using the notchless triangular prism (NTP) specimen K_IC test, with CAD/CAM (milled, M) and 3D-printed (P) materials at 7 d and 90 d.MethodsLucitone 199 (C), Lucitone 199 CAD (M) and Lucitone Digital Print (P) (Dentsply, USA) were used to fabricate NTP specimens. Samples were stored in 37 °C water for 7 d (20/group) and 90 d (20/group) and conditioned in 23 °C water for 1 h prior to testing. For testing, samples were secured in custom-made jigs and loaded in tension until crack arrest/failure. The maximum-recorded load was used to calculate KIC. The results were analyzed by two-way ANOVA, Scheffé multiple mean comparisons (α = 0.05), independent t-tests and Weibull. WOF (in KJ/m²) was calculated by dividing the area under the load-displacement graphs by twice the corresponding crack-arrested cross sectional area of the fractured surfaces.ResultsThe results have shown that: 1) the tested materials had significantly different K_IC (P > C > M; p < 0.005) and WOF at both 7d and 90d; 2) ageing in 37 ºC water for 90 d resulted in a significant decrease of K_IC in the C and M groups (p < 0.001) and of WOF in all groups.SignificanceThe tested P denture base exhibited significantly higher K_IC and WOF, suggesting that it could be more resistant to crack propagation than the C and M materials tested. Water storage for 90 d significantly decreased K_IC of C and M materials and WOF of all.     

Effect of post-rinsing time on the mechanical strength and cytotoxicity of a 3D printed orthodontic splint material

ObjectiveSince the post-rinsing time is inconsistently recommended, this study aims to investigate the effect of post-rinsing time on the flexural strength and cytotoxicity of an stereolithographically (SLA) printed orthodontic splint material.MethodsSLA-printed specimens were ultrasonically rinsed with isopropanol (IPA) for 5 min, 12 min, 20 min, 30 min, 1 h, and 12 h, respectively. Surface characterization was conducted by scanning electron microscopy and roughness measurements. Flexural strength was evaluated using a three-point bending test. Cytotoxicity was determined by direct contact test and extract test. For both tests, cell viability (live/dead staining) and cell metabolic activity (CCK-8 assay) were evaluated. Additionally, water sorption and water solubility were tested to analyze the mass loss from immersion.ResultsNo apparent surface alterations could be detected on the samples post-rinsed for less than 1 h. In contrast, when the post-rinsing time was prolonged to 12 h, surface fissures could be observed. Flexural strength linearly decreased with increasing post-rinsing time. All post-processed specimens did not show an obvious cytotoxic effect.SignificanceThe removal of cytotoxic methacrylate monomers by post-rinsing with IPA could be achieved in 5 min. Extending post-rinsing time could not improve the cytocompatibility of the SLA-printed orthodontic splint material, and may result in a decrease in flexural strength.     

Trueness of 3D printed partial denture frameworks: build orientations and support structure density parameters

PURPOSEThe purpose of the study was to assess the influence of build orientations and density of support structures on the trueness of the 3D printed removable partial denture (RPD) frameworks.MATERIALS AND METHODSA maxillary Kennedy class III and mandibular class I casts were 3D scanned and used to design and produce two 3D virtual models of RPD frameworks. Using digital light processing (DLP) 3D printing, 47 RPD frameworks were fabricated at 3 different build orientations (100, 135 and 150-degree angles) and 2 support structure densities. All frameworks were scanned and 3D compared to the original virtual RPD models by metrology software to check 3D deviations quantitatively and qualitatively. The accuracy data were statistically analyzed using one-way ANOVA for build orientation comparison and independent sample t-test for structure density comparison at (α = .05). Points study analysis targeting RPD components and representative color maps were also studied.RESULTSThe build orientation of 135-degree angle of the maxillary frameworks showed the lowest deviation at the clasp arms of tooth 26 of the 135-degree angle group. The mandibular frameworks with 150-degree angle build orientation showed the least deviation at the rest on tooth 44 and the arm of the I-bar clasp of tooth 45. No significant difference was seen between different support structure densities.CONCLUSIONBuild orientation had an influence on the accuracy of the frameworks, especially at a 135-degree angle of maxillary design and 150-degree of mandibular design. The difference in the support’s density structure revealed no considerable effect on the accuracy.     

Suitability of 3D printed pieces of nanocrystalline zirconia for dental applications

ObjectivesThe main goal of this work is to evaluate the suitability of nanostructured zirconia pieces obtained by robocasting additive manufacturing (AM), for dental applications.MethodsThe density, crystalline structure, morphology/porosity, surface roughness, hardness, toughness, wettability and biocompatibility of the produced samples were compared with those of samples obtained by conventional subtractive manufacturing (SM) of a similar commercial zirconia material. Chewing simulation studies were carried out against dental human cusps in artificial saliva. The wear of the material was quantified and the wear mechanisms investigated, as well as the influence of glaze coating.ResultsAM samples, that revealed to be biocompatible, are slightly less dense and more porous than SM samples, showing lower hardness, toughness and wettability than SM samples. After chewing tests, no wear was found both on AM and SM samples. However, the dental wear was significantly lower when AM samples were used as counterbody. Concerning the glazed samples, both coated surfaces and dental cusps suffered wear, being the cusps’ wear higher than that found for unglazed samples. More, cusps tested against AM coated samples suffered less wear comparatively to those opposed to SM coated samples.SignificanceOverall, the results presented in this paper show that AM processed nanostructured zirconia can be used in dental restorations, with important advantages from the point of view of processing and tribological performance. Moreover, the option for glaze finishing should be carefully considered both in SM and AM processed specimens.     

3D打印辅助手术治疗下颌骨缺损疗效的Meta分析

目的分析研究3D打印技术应用于下颌骨缺损治疗的文献,评价3D打印技术对下颌骨缺损重建治疗效果的影响。方法检索PubMed、MEDLINE、Cochrane图书馆、Embase、中国生物医学文献数据库、CNKI、万方数据库、维普资讯数据库正式发表的文献,检索起止时间为从建库至2019年1月,收集应用3D打印技术于下颌骨缺损重建的临床对照试验,严格评价纳入研究的质量并提取数据,采用RevMan5.3软件进行Meta分析。结果共纳入10篇临床对照研究,受试者共268例,其中3D打印组124例,非3D打印组144例;Meta分析显示,与传统的非3D打印技术辅助手术重建下颌骨相比,3D打印辅助技术组的术中组织缺血时间短(SMD=-39.78,95%CI为-57.85至-21.71,P<0.01)、重建时间短(SMD=-31.90,95%CI为-43.12至-20.68,P<0.01)、手术时间短(SMD=-76.93,95%CI为-106.93至-46.92,P<0.01),下颌骨重建精确性高。结论下颌骨重建手术中应用3D打印技术具有缩短术中组织缺血与重建时间、手术时间短等优点,且能够提高下颌骨重建的精确性,提高手术效率和质量。     

Accuracy of metal 3D printed frameworks for removable partial dentures evaluated by digital superimposition

ObjectivesTo evaluate the accuracy of metal 3D printed frameworks (MEP group) for removable partial dentures (RPDs) by digital superimposition, in comparison to that of frameworks produced by the conventional (CON group) and resin printing/casting (RPC group) workflows.MethodsA partially edentulous maxillary dentiform was prepared with rest seats and guiding planes on the right canine, left first premolar, and left second molar. Thirty master casts were prepared via repeated impressions of the dentiform. Frameworks were fabricated by three different workflows (n = 10 for each group). The internal discrepancies of the frameworks were assessed at 12 points by digital scanning with an optical triangulation principle-based tabletop scanner and superimposition using a reference best-fit alignment method. First, the master cast was scanned alone. Subsequently, a thin silicone material was applied to the framework and fitted onto the master cast, after which the framework was removed. Finally, the master cast with the silicone material attached was rescanned. The data from the two scans were matched, with the reference being the area not occupied by the silicone.ResultsFor the CON, MEP, and RPC groups, respectively, the mean overall internal discrepancies (279.72 µm, 241.02 µm, and 331.70 µm), and the mean internal discrepancies on palate areas (292.92 µm, 250.72 µm, and 355.84 µm) and rest seat areas (240.12 µm, 211.91 µm, and 259.26 µm) did not significantly differ among the three fabrication methods (p = 0.558, 0.542, and 0.774).SignificanceThe reference best-fit alignment of scan datasets is a useful approach to evaluate the internal discrepancy of frameworks. Metal 3D printing produces RPD frameworks that are comparable to conventional frameworks and meet clinical standards.     

3D printed versus conventionally cured provisional crown and bridge dental materials

Objectives

To optimize the 3D printing of a dental material for provisional crown and bridge restorations using a low-cost stereolithography 3D printer; and compare its mechanical properties against conventionally cured provisional dental materials.

Cytotoxicity of 3D printed resin materials for temporary restorations on human periodontal ligament (PDL-hTERT) cells

ObjectivesVarious dental resin materials are available for the fabrication of temporary restorations using modern additive printing methods. Albeit these materials are placed for several months in intimate contact with dental hard and soft tissues, including the gingival crevice, there exists only insufficient evidence on the biocompatibility of these materials. This in vitro study aimed to delineate the biocompatibility of 3D printable materials on periodontal ligament cells (PDL-hTERTs).MethodsSamples of four dental resin materials for additive fabrication of temporary restorations using 3D printing (MFH, Nextdent; GC Temp, GC; Freeprint temp, Detax; 3Delta temp, Deltamed), one material for subtractive fabrication (Grandio disc, Voco) and one conventional temporary material (Luxatemp, DMG) were prepared with a standardized size according to the manufacturer’s instructions. Human PDL-hTERTs were exposed to resin specimens or eluates of the material for 1, 2, 3, 6 and 9 days. For determination of cell viability, XTT assays were performed. In addition, the expression of the proinflammatory cytokines interleukin 6 and 8 (IL-6 and 8) was assessed in the supernatants with ELISA. Cell viability and the expression of IL-6 and 8 in presence of the resin material or their eluates was compared with untreated controls. Immunofluorescence staining for IL-6 and IL-8, as well as scanning electron microscopy of the discs after culturing, were performed. Differences between groups were analyzed with Student´s t-test for unpaired samples.ResultsCompared to untreated control samples, the exposure against the resin specimen induced strong reduction of cell viability in case of the conventional material Luxatemp (p < 0.001) and the additive material 3Delta temp (p < 0.001) irrespective of the observation period. On the contrary, the presence of eluates of the various materials induced only minor changes in cell viability. Considering IL-6 (day 2: p = 0.001; day 6 and 9: p < 0.001) and IL-8 (day 1: p = 0.001; day 2, 3, 6, 9: p < 0.001) their expression was strongly reduced in presence of the eluate of Luxatemp. Except for IL-6 at day 1 and 6 also the material 3Delta temp caused significant reduction of both proinflammatory mediators at any time point.SignificanceThe conventional material Luxatemp and the additive material 3Delta temp appear to severely affect cell viability when in direct contact with PDL-hTERTs. The other tested materials of this new category of additive materials and the subtractive material Grandio seem to induce only minor changes in direct contact with these cells. Therefore, they could serve as a viable alternative in the fabrication of temporary restorations.     

Color alterations,flexural strength,and microhardness of 3D printed resins for fixed provisional restoration using different post-curing times

ObjectivesTo evaluate the effect of post-curing times on the color change, flexural strength (FS), modulus (FM) and microhardness at different depths of four 3D printed resins.Materials and methodsA characterization of the light emitted by 3D-resin post-curing unit (Wash and Cure 2.0, Anycubic) was performed. The tested 3D printed resins were Cosmos Temp3D (COS), SmartPrint BioTemp (SM) Resilab3D Temp (RES) and Prizma3D BioProv (PRI) were evaluated under five different post-curing conditions (no post-curing or 5-, 10-, 15, and 20 min of post-curing). For color change analysis, 10 mm diameter x 1 mm thick discs (n = 7) were printed, and the luminosity, color and translucency were measured before post-curing as control, and repeatedly after 5 min cycles of post-curing until a total of 20 min was reached for ΔE₀₀ [CIED2000 (1:1:1)] calculation. For FS and FM, 25 × 2×2 mm (n = 10, for each post-curing time) 3D printed bars were subjected to a 3-point being test. Knoop microhardness (KHN) was measured transversally on 5 × 5×5 mm blocks (n = 10, for each post-curing time). Color results were analyzed by one-way repeated measures ANOVA (factor: color change). FS and FM were analyzed by two-way ANOVA (factors: Material*Post-Curing Time). KHN was analyzed individually for each material by two-way ANOVA (factors: Depth*Post-Curing Time).ResultsThe post-curing time significantly influenced the ΔE_00, FS, FM and KHN of all the evaluated materials. COS and SMA presented ΔE₀₀ values above the acceptability threshold after 5 and 10 min of post-curing, respectively. The FS of RES reached a plateau after 5 min of post-curing, and for PRI and SMA, the FS stabilized after 10 min of post-curing. The post-curing process improved the KHN of the tested materials, and longer exposure periods were associated to higher KHN values at all the evaluated depths.SignificanceA fine adjustment of the post-curing time is crucial to produce adequate mechanical properties in 3D-printed restorative resins, while minimizing the color alterations on the restorations. For the evaluated resins, 5–10 min of post-curing will result in adequate mechanical properties, without affecting the acceptability in the color of the material. However, the results are material-dependent, and evaluation of each specific resin is advised.     

Peel bond strength between 3D printing tray materials and elastomeric impression/adhesive systems: A laboratory study

ObjectivesThe present study aimed to evaluate the bonding between three 3D printed custom tray materials and three elastomeric impression/adhesive systems using the peel test.MethodsTest blocks were 3D printed by three different technologies using Dental LT, FREEPRINT tray, and polylactide (PLA) tray materials. The reference test blocks were conventionally fabricated with Zeta Tray LC, a light-curing resin. The surface topographies of the four tray materials were investigated by scanning electron microscopy (SEM) analyses and roughness measurements. The peel bond strength between the four tray materials and three impression/adhesive systems, vinylsiloxanether (VSXE), vinyl polysiloxane (VPS), and polyether (PE), was measured (n = 12 per group). The peeling failure modes and rupture sites were identified microscopically.ResultsThe four tray materials featured different surface topographies. The peel bond strength was not significantly different with VSXE and PE, but PLA and the reference showed higher peel bond strength with VPS than the Dental LT and FREEPRINT tray (p < 0.05). The rupture site of adhesive failure in all groups was partly at the adhesive-impression material interface and partly within the adhesive but never at the adhesive-tray material interface.SignificanceThe 3D printed tray materials can achieve satisfactory chemical compatibility with the adhesives of VSXE, VPS, and PE. Surface topographies generated by the 3D printing technologies may affect bonding. Generally, 3D printed tray materials can provide clinically adequate bond strength with the elastomeric impression/adhesive systems. PLA is recommended for bonding with VPS when severe impression removal resistance is detected.     

3D打印钴铬合金和铸造钴铬合金的理化性能和生物相容性的比较

目的 比较3D打印和传统铸造钴铬合金的理化性能及生物学影响.方法 实验组和对照组分别用3D打印技术中的选择性激光熔融(SLM)和传统铸造技术,制作钴铬合金试件各10个,采用洛氏硬度计HR-150A和金相显微镜对两组分别进行洛氏硬度测定和金相观察,并在自腐蚀电位下对金属试件进行极化曲线测定.在无菌环境下制备试件的浸提液,...     

3D打印技术在口颌面治疗中的应用进展

研究3D打印技术的发展其及在口颌面治疗中的应用现状.查阅PubMed、Web of Science、Elsevier ScienDirect、万方、维普期刊、中国知网等数据库.3D打印技术首先被应用于工业工程领域,随后被推广到临床医学领域,主要涉及骨科、心胸外科、口腔科、神经外科等.3D打印技术对于制造大规模的个性化产品具有划时代的意义,其在口腔医学上的应用将成为一种必然趋势.     

Development of 3D printed dental resin nanocomposite with graphene nanoplatelets enhanced mechanical properties and induced drug-free antimicrobial activity

ObjectivesOral prosthetic rehabilitation has been used for a long time to restore function and natural appearance; however, it is still one of the most challenging areas in dentistry due to its technical fabrication process and biological behavior. Considering the advantages of additive manufacturing technology, this study introduced the feasibility of developing a 3D printed resin-based composition modified with graphene nanoplatelets (GNPs) to improve properties.MethodsAcrylate-based resin was impregnated with different concentrations of GNPs (0.0–0.25 wt%), and then different aspects such as mechanical, physical, biological and antimicrobial were analyzed to evaluate the effectiveness. TEM and SEM were used to characterize GNPs and their existence within the resin. Surface topography and roughness were evaluated using AFM. The degree of conversion and composition were confirmed by FTIR. Mechanical properties were detected using bending strength, microhardness and nanoindentation. Biocompatibility and antimicrobial activities were assessed with oral fibroblast and Candida albicans (C. albicans), respectively. In addition, most of the measurements were performed repeatedly after 3 months of storage in artificial saliva to evaluate performance.ResultsGNPs improved strength significantly at low concentrations ≤ 0.05 wt%, while the addition up to 0.25 wt% enhanced printed nanocomposite hardness and elasticity. The modification did not induce a toxic response, as its biocompatibility was within the recommended range of biomedical devices. Antimicrobial activity was of prominence, as GNPs showed an outstanding route of reducing C. albicans activity associated with filler proportion.SignificanceThe embedment of GNPs in 3D printed resin can become a key material for customized applications that require high antimicrobial, stiffness and strength properties.     

Elution behavior of a 3D-printed,milled and conventional resin-based occlusal splint material

ObjectiveThe elution of unpolymerized (co-)monomers and additives from methacrylic resin-based materials like polymethyl methacrylate (PMMA) can cause adverse side effects, such as mutagenicity, teratogenicity, genotoxicity, cytotoxicity and estrogenic activity.The aim of this study was to quantify the release and the cytotoxicity of residual (co-)monomers and additives from PMMA-based splint materials under consideration of real splint sizes. Three different materials used for additive (3D printing), subtractive (milling) and conventional (powder and liquid) manufacturing were examined.MethodsThe splint materials SHERAprint-ortho plus (additive), SHERAeco-disc PM20 (subtractive) and SHERAORTHOMER (conventional) were analysed. 16 (n = 4) sample discs of each material (6 mm diameter and 2 mm height) were polished on the circular and one cross-section area and then eluted in both distilled water and methanol. The discs were incubated at 37 °C for 24 h or 72 h and subsequently analysed by gas chromatography/mass spectrometry (GC/MS) for specifying and quantifying released compounds. XTT-based cell viability assays with human gingival fibroblasts (HGFs) were performed for Tetrahydrofurfuryl methacrylate (THFMA), 1,4-Butylene glycol dimethacrylate (BDDMA) and Tripropylenglycol diacrylate (TPGDA). In order to project the disc size to actual splint sizes in a worst-case scenario, lower and upper jaw occlusal splints were designed and volumes and surfaces were measured.ResultsFor SHERAeco-disc PM20 and for SHERAORTHOMER no elution was determined in water. SHERAprint-ortho plus eluted the highest THFMA concentration of 7.47 μmol/l ±2,77 μmol/l after 72 h in water. Six (co-)monomers and five additives were detected in the methanol eluates of all three materials tested. The XTT-based cell viability assays resulted in a EC₅₀ of 3006 ± 408 μmol/l for THFMA, 2569.5 ± 308 μmol/l for BDDMA and 596.7 ± 88 μmol/l for TPGDA.SignificanceWith the solvent methanol, released components from the investigated splint materials exceeded cytotoxic concentrations in HGFs calculated for a worst-case scenario in splint size. In the water eluates only the methacrylate THFMA could be determined from SHERAprint-ortho plus in concentrations below cytotoxic levels in HGFs.     

基于3D打印水凝胶技术的显微外科仿真训练教具的研制与应用效果评价

目的 采用3D打印水凝胶技术制作微小仿真血管,以此为基础,研发一种显微外科训练教具,并评估其教学效果和适用性。方法 利用3D打印水凝胶技术制作微小血管,设计管路连接系统、血液循环泵等部件,研制出显微外科仿真训练教具。从空军军医大学口腔医院口腔颌面外科选择10名具有丰富显微外科经验的教师,试用新教具,通过问卷打分形式评价其与传统显微外科训练教具之间的差别。选择24名口腔医学专业第五年实习学生,随机分为对照组和实验组,每组12人,对照组学员用传统的橡皮片、软质胶管为教具进行训练,实验组学员用新教具进行训练,共训练10 d,2 h/d;训练结束后,2组学员均以吻合小鼠颈动脉进行考核打分。通过问卷调查、考核成绩评估教具使用的实用性与教学效果。采用SPSS 19.0软件包对数据进行统计学处理。结果 成功研发出一套以3D打印水凝胶血管为核心,带有液体循环系统的新型显微外科训练教具。对10名教师的问卷结果显示,新教具在实用性、科学性方面优于传统教具,实验组学员的考核成绩显著高于对照组（P<0.05）。结论 基于3D打印水凝胶血管技术研发的仿真显微外科训练教具实用性强、成本低,教学效果优于传统教学模式,值得推广应用。