Geomagic Qualify Software Research Articles

Evaluation of the mechanical properties and fit of 3D-printed polyetheretherketone removable partial dentures.

Compared with CAD/CAM, fused deposition modeling (FDM) 3D printing technology is simple and safe to operate and has a low cost and high material utilization rate; thus, it is widely used. The present investigation aimed to evaluate the mechanical properties and fit of polyetheretherketone (PEEK) removable partial dentures (RPDs) constructed by FDM. We analyzed mechanical properties of PEEK samples prepared by FDM, milling, or injection molding. RPDs were designed and finite element analysis models was constructed to evaluate maximum stress and strain in the RPDs, cortical bone and mucosa. Geomagic Qualify software was used to analyze gaps between the model and the tissue surface of the framework. The results showed that the compressive strength of the 3D-printed PRDs was greater than that of the injection-molded samples. Finite element analysis demonstrated that the maximum stress on the PRDs was less than the yield strength of the material. Overall, the mechanical properties and fit of the PEEK RPD fabricated by FDM technology essentially fulfilled clinical requirements.

Accuracy of Orthodontic Indirect Bracket Bonding by CAD/CAM Transfer Tray

Introduction: Indirect bonding is a technique in which orthodontic attachments are transferred from dental casts (working models) and bonded onto dentition using a transfer tray. Indirect bonding is a preferred technique for many orthodontists as it is less time consuming compared to direct bonding. Evolution in technology allowed forming transfer trays digitally by the integration of computer-aided design and computer-aided manufacturing (CAD/CAM). This study was conducted to measure transfer accuracy of CAD/CAM indirect three dimensional printed bonding trays. Materials and methods: 140 teeth (all upper and lower incisors, canines and premolars) in 7 patients were bonded by vacuum-formed transfer tray formed on 3 dimensional (3D) printed models with resin brackets. Intra oral scanner was used initially to obtain stereolithographic file for virtual brackets positioning and another scan was taken after brackets bonding. Superimposition of virtual STL files and post bonding STL files was done by Geomagic Qualify software to measure linear and angular deviation of brackets positions. Results: One sample t-test was performed to determine whether the mean transfer error was statistically within the selected acceptable limits of 0.5 mm for linear measurements. P-values of less than 0.05 indicated differences within the limits of 0.5 mm for linear measurements. All brackets were transferred within the accepted deviation limits Conclusions: CAD/CAM designed and printed transfer trays had high transfer accuracy in linear measurements in all teeth.

Do low-cost 3-dimensional printers produce suitable dental models?

When choosing a 3-dimensional printer for dental models, the cost-benefit ratio should be evaluated. The purpose of this study was to evaluate the accuracy, precision, cost, and time taken to prepare and print using different low-cost techniques (2 digital light processing [DLP] and 1 fused filament fabrication [FFF] printer) compared with the reference proven to be clinically accepted (PolyJet). For this purpose, the upper and lower virtual models of 5 patients were printed using: (1) DLP printer Moonray, (2) DLP printer Anycubic, (3) DLP printer Moonray with Anycubic resin, (4) Filament printer UpMini 2 (FFF), and (5) Polyjet printer Objet Eden500V. One of the virtual models was also printed 4 consecutive times on each printer to allow consistency assessment. Afterward, the 14 printed resin models were scanned, and their accuracy was evaluated by model superimposition using Geomagic Qualify software (3D Systems, Rock Hill, SC). A digital caliper was also used to obtain linear measurements. All measurements were carried out by a calibrated examiner. The results showed that all printers produced similar results, although Moonray with Anycubic resin showed loss of accuracy and Anycubic showed inconsistent vertical dimensions. The printing cost and time consumed from each pair of models were calculated for the overall printing process, analyzing which would have the best cost-benefit ratio. Polyjet printing was considered the fastest method but with the highest cost. FFF printing was the lowest printing and input cost but was considerably more time-consuming. There was a balance in both DLP printers, and they were considered the best cost-benefit ratio for small independent dental offices.

Reliability of a digital system for models measurements in BBO grading: A pilot study.

ABSTRACTIntroduction: Currently, no method is considered effective for the evaluation of digital models in the Certification Examination of the Brazilian Board of Orthodontics (BBO), considering the parameters of the currently used manual method. Objective: Thus, the aim of this study is to verify the reliability of an evaluation method for digital models that could be used in the BBO exam, compared to the gold standard.Methods: Measurements were performed by five previously calibrated examiners. Samples of ten sets of plaster models of the final phase of orthodontic treatment were measured using a manual method (Objective Grading System, OGS). These models were digitized using a 3D scanner and exported to Geomagic Qualify software, in which the measurements were made with the proposed digital method. These measurements were repeated using five models, after fifteen days. The intra-examiner performance with this method was analyzed with a paired t-test, whereas the inter-examiner analysis was carried out with analysis of variance and Tukey’s test. To compare the manual and digital methods, a paired t-test and Pearson’s correlation analysis were performed.Results: A statistically significant difference was found. The results showed that, when compared to the manual method, the digital method was effective in measuring the OGS in four of the seven variables studied: Marginal Ridge, Overjet, Occlusal Contact, and Interproximal Contact. The variables Alignment, BL inclination, and Occlusal Relationship showed a great amount of dispersion in the findings.Conclusion: Further studies are needed to develop an adequate digital methodology that can be used for all OGS variables.

Wear behavior of a microhybrid composite vs. a nanocomposite in the treatment of severe tooth wear patients: A 5-year clinical study

ObjectiveThis study aimed to compare the wear behavior of a microhybrid composite vs. a nanocomposite in patients suffering from severe tooth wear. MethodsA convenience sample of 16 severe tooth wear patients from the Radboud Tooth Wear Project was included. Eight of them were treated with a microhybrid composite (Clearfil APX, Kuraray) and the other eight with a nanocomposite (Filtek Supreme XTE, 3M). The Direct Shaping by Occlusion (DSO) technique was used for all patients. Clinical records were collected after 1 month (baseline) as well as 1, 3 and 5 years post-treatment. The maximum height loss at specific areas per tooth was measured with Geomagic Qualify software. Intra-observer reliability was tested with paired t-tests, while multilevel logistic regression analyses were used to compare odds ratios (OR) of “large amount of wear”. ResultsIntra-observer reliability tests confirmed that two repeated measurements agreed well (p > 0.136). For anterior mandibular teeth, Filtek Supreme showed significantly less wear than Clearfil APX; in maxillary anterior teeth, Clearfil APX showed significantly less wear (OR material = 0.28, OR jaw position = 0.079, p < 0.001). For premolar and molar teeth, Filtek Supreme showed less wear in bearing cusps, whereas Clearfil APX showed less wear in non-bearing cusps (premolar: OR material = 0.42, OR bearing condition = 0.18, p = 0.001; molar: OR material = 0.50, OR bearing condition = 0.14, p < 0.001). SignificanceNanocomposite restorations showed significantly less wear at bearing cusps, whereas microhybrid composite restorations showed less wear at non-bearing cusps and anterior maxillary teeth.

Dimensional accuracy and clinical adaptation of ceramic crowns fabricated with the stereolithography technique

Statement of problemThe stereolithography technique has been a promising method of fabricating fracture-resistant ceramic restorations efficiently. However, studies on the dimensional accuracy and clinical adaptation of ceramic crowns fabricated with the technique are lacking. PurposeThe purpose of this in vitro study was to evaluate the dimensional accuracy and clinical adaptation of ceramic crowns fabricated with the stereolithography technique. Material and methodsA typodont maxillary right first molar abutment tooth was scanned by using an extraoral scanner, and a crown was designed by using 3Shape Dental System CAD software. Ten ceramic crowns were fabricated with 2 different stereolithography systems, CeraFab7500 (CF) alumina and CSL150 (CL) zirconia, and a conventional computer-aided design and computer-aided manufacturing system, X-MILL500 (XM) zirconia. The crowns were scanned, and the digital casts were exported. Dimensional accuracy was measured by superimposing the digital casts with the reference model by using Geomagic Qualify software. The silicone replica method was applied to measure clinical adaptation. Results were statistically analyzed by using a 1-way analysis of variance (α=.05). ResultsCeraFab7500 reported better dimensional accuracy (41 ±11 μm) than CSL150 (65 ±6 μm) or X-MILL500 (72 ±13 μm) (P<.001). No significant difference was found between the CSL150 and X-MILL500 groups (P>.05). X-MILL500 reported significantly better adaptation in the marginal, corner, and occlusal areas but inferior adaptation in the axial area compared with CeraFab7500 and CSL150 (P<.05). Significant differences were only apparent in the axial and occlusal areas between CeraFab7500 and CSL150 (P<.05). No significant difference was found in the marginal or corner area between CeraFab7500 and CSL150 (P>.05). ConclusionsBoth CeraFab7500 and CSL150 can fabricate ceramic crowns with high dimensional accuracy and marginal adaptation within clinically acceptable limits. The results indicate that the fabrication of ceramic crowns by using the stereolithography technique seems to be promising.

Comparison of the Accuracy of Three-Dimensional Printed Casts, Digital, and Conventional Casts: An In Vitro Study.

Objectives The integration of computer-aided design and manufacturing technologies in diagnosis, treatment planning, and fabrication of prosthetic restoration is changing the way in which prosthodontic treatment is provided to patients. The aim of this study was to compare the accuracy of three-dimensional (3D) printed casts produced from the intraoral scanner using stereolithographic (SLA) 3D printing technique, their digital replicas, and conventional stone casts. Materials and Methods In this in vitro study, a typodont of maxillary and mandibular arches with full dentate ivory teeth was used as a reference cast. The typodont was digitized using Trios 3Shape intraoral scanner to create digital casts. The digital files were converted into 3D printed physical casts using a prototyping machine that utilizes the stereolithography printing technology and photocurable polymer as printing material. Linear measurements (mesiodistal and occlusocervical) and interarch measurements (intercanine and intermolar) were made for digital and prototyped models and were compared with the original stone casts. The reference teeth were canines, first premolars and second premolars in the maxillary and mandibular arches on the right and left sides. The measurements on printed and conventional casts were done by digital caliper while on digital casts; Geomagic Qualify software was used. Statistical Analysis One-way analysis of variance (ANOVA) was used to compare measurements among groups. Results Digital casts showed significantly higher error than the other two groups in all linear and interarch measurements. The mean errors of the digital cast in occlusocervical (OC) and mesiodistal (MD) measurements (0.016 and 0.006, respectively) were higher compared with those in the other two groups (OC, 0.004 and 0.007 and MD, 0.003 and 0.005 [ p < 0.0001 and p = 0.02, respectively]). Also, digital mean error in intermolar width (IMW) and intercanine width (ICW) (0.142 and 0.113, respectively) were greater than the other two groups (IMW, 0.019 and 0.008 and ICW, 0.021 and 0.011 [ p < 0.0001]). However, the errors were within the acceptable clinical range. Conclusion The 3D printed casts may be considered as a substitute for stone casts with clinically acceptable accuracy that can be used in diagnosis, treatment planning, and fabrication of prosthetic restorations.

Effect of different support angles on the fitness of removable partial denture framework fabricated using selective laser melting technique

Objective: To evaluate the fitness of bilateral free-end dentition defect removable partial denture framework fabricated by selective laser melting (SLM) technique with different support angles. Methods: After the control group has been set to eliminate the system error, and according to the standard model of bilateral mandibular posterior teeth loss, eighteen titanium alloy removable partial denture frameworks fabricated by SLM technology were divided into 3 groups with support angles of 0° (horizontal group), 45°(45° group) and 90° (vertical group). Plaster cast with duplicated structure of tissue surface of the removable partial denture (RPD) framework was obtained. A three-dimensional scanner was used to scan original and duplicated plaster casts. The gaps between framework and the model in different parts were analyzed using Geomagic Qualify software to evaluate the fitness of the framework with visual method. Results: The framework fits on the plaster model completely, and its tissue surface fitted on the plaster model well. The deviation between frameworks and plaster casts was calculated as follow: the total deviations of the horizontal, 45°, and vertical group were (0.146±0.017), (0.182±0.015) and (0.185±0.022) mm respectively. The mean deviation of the horizontal group was significantly less than those of the 45° group and the vertical group (P<0.05). Moreover, there was no significant difference in the total deviation between the 45° group and the vertical group. The total deviation of occlusal rest of the horizontal group was significantly less than that of the 45° group (P<0.05). However, no significant difference was detected in the deviation of occlusal rest among the vertical group, the horizontal group, and the 45° group (P>0.05). There was no significant difference in the deviation of occlusal rest among the vertical group, the horizontal group, and the 45° group. The deviation of clasp of the horizontal group was significantly smaller than those of the 45° group and the vertical group (P<0.05). Whereas, there was no significant difference in the deviation of clasp between the 45° group and the 90° group (P>0.05). No significant difference was found in the deviation of lingual bar among the three groups (P>0.05). Conclusions: Among the three kinds of bilateral free-end dentition defect RPD framework fabricated by SLM in different support angles, horizontal printing was proved to reach the minimal deviation, even though the fitness of all three kinds of frameworks can fullfil clinical requirements according to previous studies.

High-accuracy and high-performance WAAM propeller manufacture by cylindrical surface slicing method

The propeller is the important component of the power system in ships, the blades of which are spatial curved structures with continually changing sections. Wire arc additive manufacture (WAAM) is a novel technology and an effective method for manufacturing propellers. Currently, the planar slicing methods cannot form the high-accuracy propellers with complex spatial curves, a new cylindrical surface slicing method, based on the principles of conformal slicing, is applied to WAAM, the section for slicing being a cylindrical surface coaxial with the hub. Both cylindrical circumferential filling and cylindrical axial filling are used for filling the blades. In the manufacturing process, the hub is firstly formed by plane slicing and offset filling, then the blade is formed piece by piece by cylindrical slice and cylindrical axial filling and cylindrical circumferential filling alternately. A non-contact 3D measuring is conducted with a surface structure light 3D scanner after the completion of printing, and a 3D comparison is made with Geomagic qualify software. The dimensional error of the product is within ± 1.6 mm. The mechanical properties of WAAM propeller components are higher than the casting ones with the same composition.

Residents' journal review

Residents' journal review

Accuracy of printed dental models made with 2 prototype technologies and different designs of model bases.

The aim of this study was to compare the accuracy of printed models from intraoral scans with different designs of model bases, using 2 types of 3-dimensional printing techniques. Three types of model base design were created: regular base, horseshoe-shaped base, and horseshoe-shaped base with a bar connecting the posterior region. The digital models were printed with the 3-dimensional printers using different techniques: stereolithography and triple jetting technology (polyjet). The printed models were then scanned with a computed tomography scanner and a desktop laser scanner to create the respective digital models. Evaluation of the accuracy was done by measuring the dentitions with Ortho Analyzer software (3Shape, Copenhagen, Denmark) and by model superimposition with Geomagic Qualify software (3D Systems, Rock Hill, SC). An observer measured the distances twice, with an interval of 2weeks. The accuracy of the printed models was statistically evaluated by the mixed-effects regression model approach. The results showed that printed models made by the polyjet printer were accurate, regardless of the design of the model base. Printed models made with the stereolithography technique with the regular model base and the horseshoe-shaped base with a bar were accurate, but the transversal distances measured on the printed models with a horseshoe-shaped base were statistically significantly smaller. Printed models with a regular base or a horseshoe-shaped base with a bar were accurate regardless of the printing technique used. Printed models with a horseshoe-shaped base made with the stereolithography printer had a statistically significant reduction in the transversal dimension that was not found in the models printed with the polyjet technique.

Are there differences between comparison methods used to evaluate the accuracy and reliability of digital models?

ABSTRACTObjectives: The accuracy and reliability of plaster models and digital models acquired with two different surface laser scanners were tested by means of three methods: measurement with calipers, digital measurement with proper software and superimposition of the digital models. Methods: Thirty plaster models with permanent dentition that met the inclusion criteria were selected and scanned with two laser scanners (R700 and Xcad). Three examiners measured distances on plaster models with a digital caliper and on digital models using Ortho Analyzer software. The digital models were also compared by means of superimposition of the models using the Geomagic Qualify software. The intra and inter-examiner reliability of the measurements were evaluated using the ICC. Paired t test was used to test the accuracy of the measurements on digital and plaster models.Results: The measurements on plaster and digital models acquired by two different scanners showed high values for the ICC. Although statistically significant differences between the measurements on plaster and digital models have been found, these discrepancies were not considered clinically relevant. The superimposition method with Geomagic Qualify software showed that the two digital models were not significantly different.Conclusions: Digital models created from scanned plaster models using the R700 or Xcad scanners were clinically accurate according to the two methods of comparison used.

Elastic-Plastic Numerical Simulation of Cold Rotary Forging for Hypoid Gear and the Springback Error

To achieve the effect of anti-fatigue manufacturing for hypoid gear, the author put forward a new type cold rotary forging technology, the method simplifies the die structure and adopts the local line contact continuous plastic forming. Based on the basic theory of elastic-plastic finite element method (FEM),the author uses ABAQUS to carry out numerical simulation of cold rotary forging and discuss how to build finite element geometric model and grid it in detail, and analyse the definition of workpiece material model in ABAQUS and the merger technology of Abaqus / Explicit and Abaqus / Standard. In order to measure springback error accurately, the alveolar surface shap after springback was got through the technology of surface reconstruction, it was put into Geomagic Qualify software and compare with target CAD model,then the springback error can befully assessed through comparing results.The examles proof that ABAQUS can simulate the deformation and springback process accurately, springback error of cold rotary forging can not be ignored,so springback error must be compensated.

Precision Analysis of the Surface Reconstruction Model Based on Geomagic Qualify

Use Geomagic Qualify software, take the distance between the measure point and the surface model as the main evaluation index, respectively evaluate the quality of the shoe last surface reconstructed by tradition surface modeling way and quickly surface modeling approach, through 3D comparison, 2D comparison and special point comparison, get the 3D deviation chart and the error percentage distribution list, through the analysis and comparison of the charts, the two ways of surface reconstruction method are in line with the requirements of the surface, select the appropriate method of surface reconstruction according to the different requirements of surface reconstruction quality, provide the reference basis to surface measurement and surface reconstruction of other models.

Building Three-Dimensional Scanner Based on Structured Light Technique Using Fringe Projection Pattern

This paper presents the design and construction of a low-cost active noncontact three-dimensional (3D) scanner using the structured light method. The applied method is a generalization of the triangulation technique using a fringe projection pattern (by Gray code technique) to achieve a higher operating speed. The hardware equipment includes a single digital camera and a video projector. matlab was used for the calibration operation, the production of images by the above method, the image processing, and data calculation; while the Geomagic Qualify software was used to estimate the accuracy of the three-dimensional model obtained after scanning and to compare it with the tested object. Regarding the point cloud of the test object, the results demonstrate the precision of the used method and the possibility of developing a 3D scanner with a dimensional accuracy of ±0.05 mm.