Cast Fabrication Research Articles

Challenges and Solutions for Cost-Effective and Practical Dental Cast Fabrication With a Desktop Fused Deposition Modeling (FDM) 3D Printer

Challenges and Solutions for Cost-Effective and Practical Dental Cast Fabrication With a Desktop Fused Deposition Modeling (FDM) 3D Printer

In-Vitro Accuracy of Digital Versus Conventional Workflows for Complete Arch Implant Supported Frameworks - A Scoping Review.

Purpose: To investigate the available evidence on the accuracy of conventional and digital workflows for complete arch implant supported frameworks. Materials and methods: This scoping review was conducted according to the 5-stage framework of Arksey and O'Malley. A systematic literature search was performed adhering to the PRISMA guidelines to identify studies with a direct comparison of conventional and digital methods for the fabrication of complete arch implant supported frameworks. 58 in-vitro studies with the focus on edentulous arches with at least four implants published between 2000 and 2024 were included. The reported outcomes were examined to determine the value of a statistical analysis for adding up the individual errors to a cumulative error of the workflow. Results: Evidence on the accuracy assessment of digital and conventional workflows for complete arch implant supported frameworks is available. However, also studies with the same assessment methods and outcome units appear to be too heterogeneous to perform a statistical analysis of error accumulation. While there is no consensus in the impression and cast fabrication stage, digital techniques show a superior accuracy for the fabrication of complete arch implant supported frameworks compared to conventional casting. Conclusion: In-vitro studies assessing the accuracy of entire workflows and classifying their outcomes regarding the clinical relevance are lacking.

Assessment of fully digitalized workflow for implant-prosthetic rehabilitation in temporomandibular disorders patients: A clinical study

Digitalized workflow eliminates the need for the tray, impression materials, its decontamination, packaging and shipping, pouring with plaster, cast fabrication, mounting in an articulator, reducing storage spaces, and the risks of any loss or fracture of the plaster model is overcome by archiving on the computer. This clinical investigation aimed to evaluate the effectiveness of the fully digitalized rehabilitation [implant-supported prosthesis] method in partially edentulous patients and with TMD, using advanced software. Twelve patients requiring implant-supported prosthesis in the mandibular molar area with Temporomandibular disorders [TMD] were selected. The fully digitalized rehabilitation method with advanced software was used for rehabilitation. For each subject, Optical impressions, CBCT scan, and Digital recording of jaw movement data. Guided implant surgery and digitalized prosthetic rehabilitation; were performed. The effectiveness of the digitalized workflow was assessed by evaluating the changes in the joint symptoms before and after the end of the treatment, changes in the electromyographic tracings, the precision of the prosthetic artefact, assessed through the amount of chair adjustment operating time and the number of retouching/ modifications to be carried out before the completion of the work. The results showed that the mean operative time required in 12 patients was 9.42 min, significantly less than the time recorded in previous studies when the medium mean was 16.00 min. The mean number of touch-ups [adjustments] was less than 3, most of which were on the interproximal surfaces. There were no significant changes recorded in the electromyography tracings. There were also no changes in joint symptoms. It was found that this way of working was entirely reliable and significantly reduced operating times and the number of appointments. Digital flow is beneficial ei dysfunctional patients, not about improvements in temporomandibular symptoms but in times of operability and prosthetic retouching.

Self-assessment skills of undergraduate dental students in the preclinical course of complete removable prosthodontics at Tehran University of Medical Sciences.

This study evaluated the self-assessment skills of third-year dental students regarding their performance in complete removable prosthodontics (CRP) preclinical course. This cross-sectional study was conducted on all third-year dental students attending the International Dental College of Tehran University of Medical Sciences. The students were requested to self-assess their performance in primary impression making, custom tray fabrication, border moulding, final impression making, master cast fabrication, record-base fabrication and tooth arrangement in CRP preclinical course. The performance of dental students in each step was scored by themselves and their mentors. Data were analysed by the Mann-Whitney U, Pearson's correlation and t-tests (α = 0.05). Totally 25 male (55.6%) and 20 female (44.4%) dental students were evaluated. Significant differences were noted between male and female dental students in self-assessment scores regarding adequate extension of the custom tray (p = .027), the correct position of tray handle (p = .020), visibility of vestibular width and depth on the cast (p = .011), the coincidence of upper and lower midlines (p = .005) and correct orientation of maxillary and mandibular planes in the articulator (p = .036). The mean self-assessment score of female students was significantly higher than that of male students (p = .01). The scores given by the mentors were not significantly different for male and female students (p = .975). The difference between the self-assessment score of students and the mentor score was not significant (p = .067) either in males or in females (p > .05). Undergraduate dental students favourably self-assessed their performance in all steps of the preclinical course of CRP, comparable with their mentor assessment.

Accuracy of 3D-Printed Master Cast Workflow Using a Digital Light Processing Printer

This in vitro study was designed to investigate whether conventionally produced casts and printed casts for prosthodontic purposes show comparable full-arch accuracy; a ceramic reference cast with inlay and crown preparations was fabricated. Ten gypsum casts were fabricated from conventional silicone elastomeric impressions. Ten digital impressions [IOS] of the reference cast were obtained by an intraoral scanner to fabricate 3D-printed resin casts. The ceramic reference cast, the gypsum, and the printed casts were digitized by an industrial structured light scanner (ILS) and provided as stl files. To evaluate absolute mean trueness values, the digitized gypsum casts [CON], digitized printed casts [PRINT], and [IOS] were superimposed with the digitized ceramic reference cast [REF]. Additionally, each [IOS] scan was compared with its corresponding [PRINT]. The precision was calculated for [CON], [IOS], and [PRINT]. The Mann–Whitney U test for independent samples and the Wilcoxon test for connected samples were performed (p ≤ 0.05). As absolute mean deviation trueness values were obtained: 69 ± 24 µm for [REF]-[CON], 33 ± 4 µm for [REF]-[PRINT], and 19 ± 3 µm for [REF]-[IOS]. The superimposition [IOS]-[PRINT] revealed 38 ± 6 µm. The precision was 74 ± 22 µm for [CON], 32 ± 10 µm for [PRINT], and 15 ± 4 µm for [IOS]. With respect to the workflow, the trueness values of [REF]-[CON] and [REF]-[PRINT] differed significantly. Within the digital workflow, [REF]-[PRINT], [REF]-[IOS], and [IOS]-[PRINT], all values differed significantly. Within the limitations of the study, digital impression and printed cast fabrication were more accurate and reproducible than the conventional workflow.

Study of 3D scanning technologies and scanners in orthodontics

Digital dental scanners are devices which are used to capture optical impression of intra and extra oral structures of the patient’s mouth. The basic principle of digital scanning is based upon optical phenomena like optical triangulation, coherence tomography, parallel confocal imaging and three-dimensional motion videos capturing technique. In orthodontic practice, digital scanners can be successfully used in efficient treatment planning, custom appliance fabrication, clear aligner technology and orthognathic surgical simulation. From digital record keeping, digital cast models, occlusogram, extra oral and intra oral scanners to software for cephalometric analysis, etc. have taken the orthodontic practice to newer heights. Intraoral digital scanner that utilizes the parallel-confocal imaging technology and point and stitch reconstruction to generate digital impressions which are accurate and powder free. Digitization has revolutionized the conventional orthodontics completely. In modern day orthodontic dental practice digital extra-oral and intra-oral scans are used to fabricate working and study cast models that facilitates construction of fixed orthodontic appliances, retainers and custom trays for lingual orthodontic procedures. Digital scanners are the new face of impression making and digital cast fabrication in dentistry. This review aims to identify advantages of utilising digitally scanned impressions over the conventional impression making techniques and application of digital scanning technology pertaining to the speciality of orthodontics in dental practice.

Nanobiocomposite organic/inorganic films to direct human primary cell behavior

The engineering of biomaterial interfaces is an area of ongoing study, with relevance in furthering the understanding of basic cell behavior as well as promoting desired outcomes for clinical applications. Here, we report a facile drop cast method to fabricate nanobiocomposite films atop medical grade Titanium (Ti) composed of both organic (chitosan, Cs) and inorganic (Laponite™, Lap) components, with scanning electron and atomic force microscopy indicating uniform and reproducible film composition. We further demonstrate controlled cell behavior of two clinically relevant primary cell types – human mesenchymal stromal cells (hMSCs) and osteoblasts – seeded atop the films. For both cell types, Cs incorporation decreased cell area and increased Form Factor (corresponding to a more rounded morphology) in a dose-dependent manner, with subsequent Lap incorporation “recovering” larger areas and more spread morphologies back toward those observed on Ti alone. Collectively, these results indicate the potential of the drop cast fabrication as a platform technique with which to predict the in vivo regenerative performance of interfacial biomaterials.

A systematic review of digital removable partial dentures. Part II: CAD/CAM framework, artificial teeth, and denture base.

This study comprehensively reviewed the current status of the digital workflow of removable partial dentures (RPDs) and summarized information about the fabrication methods and material properties of the dental framework, artificial teeth, and denture base. We performed a systematic review of the literature published in online databases from January 1980 to April 2020 regarding RPD fabrication and materials used in the related digital technology. We selected eligible articles, retrieved information regarding digital RPDs, and conducted qualitative/quantitative analyses. In this paper, the computer-aided design/computer-aided manufacturing (CAD/CAM) framework, artificial teeth, and denture base materials are reported. A variety of materials, such as cobalt-chromium alloy, titanium, zirconia, and polyether ether ketone, are used for dental CAD/CAM frameworks. The mechanical strength of the metal materials used for the CAD/CAM framework was superior to that of the cast framework. However, the fitness and surface roughness of the framework and clasp fabricated using a selective laser melting (SLM) method were not superior to those obtained via cast fabrication. Most material properties and the surface roughness of poly methyl methacrylate (PMMA) discs used for digital RPDs were superior to those of heat-cured PMMA. The use of a CAD/CAM framework and PMMA disc for digital RPDs offers numerous advantages over conventional RPDs. However, technical challenges regarding the accuracy and durability of adhesion between the framework and denture base remain to be solved. In digital fabrication, human technical factors influence the quality of the framework.

Dosimetric impact of variable bladder filling on IMRT planning for locally advanced carcinoma cervix

BackgroundTo evaluate the dosimetric impact of variable bladder filling on target and organ at risk (OARs) in cervical cancer patients undergoing chemoradiation. Forty consecutive patients with cervical cancer underwent radiotherapy planning as per the departmental protocol. All patients were asked to empty their bowel and bladder before simulation and catheterization was done. Normal saline was instilled into the bladder through Foleys till the patient had a maximal urge to urinate. Pelvic cast fabrication and CT simulation was done.Then, 30%, 50%, and 100% of the instilled saline was removed and rescans taken. Planning was done on full bladder (X) and the same plan applied to the contours with bladder volumes 0.7X (PLAN70), 0.5X (PLAN50), and empty (PLAN0). A dose of 50 Gy/25# was prescribed to the PTV and plans evaluated. Intensity-modulated radiotherapy plans with full bladder were implemented for each patient. Shifts in the center of mass (COM) of the cervix/uterus with variable bladder filling identified were noted. Statistical analysis was performed using SPSS software. A p value < 0.05 was considered significant.ResultsBladder volume in 70%, 50%, and empty bladder planning was 78.34% (388.35 + 117.44 ml), 64.44% (320.60 + 106.20 ml), and 13.63% (62.60 + 23.12 ml), respectively. The mean dose received by 95% PTV was 49.76 Gy + 1.30 Gy. Though the difference in target coverage was significant between PLAN100 and other plans, the mean difference was minimal. A decrease in bladder filling resulted in an increase in OAR dose. Variation in the increase in dose to OARs was not significant if bladder filling was > 78.34% and > 64.44% of a full bladder with respect to the bowel and rectal/bladder doses, respectively. Inconsistent bladder filling led to a maximal shift in COM (uterus/cervix) in the Y- and Z-axis.ConclusionBladder filling variations have an impact on cervico-uterine motion/shape, thereby impacting the dose to the target and OARs. It is recommended to have a threshold bladder volume of at least 70–75% of optimally filled bladder during daily treatment.Trial registrationInstitutional review board (IRB) registered by Drug Controller General (India) with registration number ECR/10/Ins/DC/2013. Trial Registration number - RGCIRC/IRB/44/2016, registered and approved on the 14th of May 2016.

Radiopaque Tissue Surface-Based Digital Registration Technique for Completely Edentulous Ridge.

An accurate image registration of the optical scan of a completely edentulous ridge to radiographic data remains challenging due to the absence of natural teeth. This article introduces a radiopaque tissue surface-based digital registration technique that enhances the accuracy of the image matching process and improves the fit accuracy of the implant surgical guide. In this workflow, a radiopaque impression body that is the replica of the edentulous ridge was used as a surface-based fiducial marker for accurate image registration between the soft and hard tissues of a completely edentulous arch. A virtual edentulous model was generated by direct digitization of the impression body and a digital image reversal technique without the need for stone cast fabrication or additional intraoral scanning. The fabricated surgical guide showed close adaptation to the edentulous ridge of the patient.

NMR diffusion studies of proton-exchange membranes in wide temperature range

The diffusion coefficients in proton-exchange perfluorosulfonated membranes fabricated by different techniques have been analyzed in the temperature range from 200 K to 300 K using NMR diffusometry in a static magnetic gradient field. The influence of the water content as well as the effects of the membrane thickness and the side-chain length on the diffusion coefficient was analyzed. It is found that the fabrication by the extrusion cast method leads to faster diffusion as compared to the solution cast fabrication method. Shorter side chains are also preferable for faster diffusion. Both the decrease of the temperature and the water content leads to a reduced diffusion coefficient, affecting the transport micromechanism in a similar way by increasing the role of the water on the pore walls with respect to proton transport. The model of confined water in Nafion pores has been applied to analyze the results. It is proposed that both conductivity and diffusion at low temperatures are determined by protonic transport of the surface water via bond defects in contrast to the bulk water or ice, where the ionic defects are responsible for the mass transport.

Generation of 3D digital models of the dental arches using optical scanning techniques

Due to a number of benefits mainly concerning orthodontic treatment planning and issues of documentation and sharing of patient records, digital models of the dental arches are more and more replacing conventional stone models in clinical orthodontics. To date, the most common approach for generating digital models of the dental arches comprises the digitization of stone models mostly by using optically-based desktop scanner systems. This indirect approach is sufficiently accurate and achieves a largely complete model surface with relatively low equipment acquisition costs. In the recent decade, however, intraoral scanners are becoming ever more established and proven in clinical practice. The great advantage of this direct approach for generating digital models is that the intermediate step of stone cast fabrication can be omitted which eliminates material and space requirements for casts. The various commercially available intraoral scanning systems are based on the application of different optical measurement techniques. Fringe (i.e., structured-light) projection and two or more camera systems lead to a bulky arrangement and to shadowing effects which limit the accessibility of undercuts and thin volume fractions such as incisal edges. Moreover, they usually require powder coating of the teeth. Confocal laser scanners eliminate these disadvantages, although the three-dimensional (3D) movement of the scanner handpiece is disadvantageous with regard to scanning speed, accuracy and reliability. Intraoral scans generally contain a source of risk for inaccuracy, because multiple single 3D images are assembled to a complete model. Recent studies, however, have shown that the trueness and precision of intraoral scanners of commercially available scanning systems is already sufficient for orthodontic applications. Current development of novel scanner technologies, e.g. based on multipoint chromatic confocal imaging and dual wavelength digital holography, will further improve the accuracy and clinical practicability of intraoral scanning. Hence, it is likely that in future intraoral scanning combined with 3D printing will completely replace conventional stone models of the dental arches.

Accuracy of 3-dimensional computer-aided manufactured single-tooth implant definitive casts

Statement of problemThe integration of the digital workflow into routine prosthodontic practice for single-tooth implant surgery and fixed prosthesis fabrication has occurred at a remarkable pace in the last 5 years. With the greater demands of esthetics and precision, the definitive implant analog cast must ensure accurate implant positioning as well as an accurate relationship to adjacent teeth. PurposeThe purpose of this in vitro study was to evaluate the accuracy of the 3-dimensional (3D) implant position of definitive casts produced by 3D printing and analog technology. Material and methodsA master patient model was created from a dentate typodont. The maxillary left central incisor was removed, and a Straumann RC implant was positioned for a screw-retained prosthesis. A laboratory scanner with an accuracy of 5 μm was used for all scanning. A scanbody was connected to the master model implant and scanned to create a master patient file, which served as the control master patient for all comparisons. The two 3D printing systems used for this study were the Statasys Objet500 (group OBJ), an industrial Polyjet production system, and the Formlabs Formlab 2 (group FORM), a budget SLA Vat system. In addition, a conventional gypsum cast (group GYP) with an implant analog was made with elastomeric impression material. With a sample size of 10 per group, each gypsum cast and 2 printed group casts were scanned with the D2000 laboratory scanner 5 times per cast. Convince software (3Shape) was used for 3D analysis to calculate accuracy. The following variables were measured: implant analog vertical displacement, horizontal displacement of implant platform and apex, degree of tilting in the vertical axis, and rotational position change around the vertical axis. Means and standard deviations were calculated for trueness. One-way ANOVA and the post hoc t test with Bonferroni correction were used to investigate any significant differences among the experimental groups (α=.05). ResultsFor vertical displacement of the implant body, group OBJ had the lowest value of –30 ±24 μm. The values obtained for OBJ and FORM were significantly different from that obtained for GYP (P<.05). For horizontal displacement of the implant shoulder, Group OBJ had the lowest value, 85 ±12 μm, and the difference among these groups was significantly different (P<.05). The value for horizontal displacement of the implant apex was 123 ±25 μm for group OBJ and not significantly different from that obtained for group GYP (136 ±40 μm) but significantly different from that obtained for group FORM (326 ±54 µm). Also, the analysis of implant body tilting in the vertical axis showed significant differences between the values obtained for groups GYP and OBJ and between the values obtained for groups OBJ and FORM. With regard to implant rotational position change around the vertical axis, the values obtained for the gypsum cast and group FORM were not statistically different from those obtained for the master patient control model (P>.05). However, the implant orientation of group OBJ was significantly different from the orientation of groups GYP and FORM (P<.05). The actual clinical relevance of these printing system discrepancies is yet to be determined because the level of clinical acceptable discrepancy in the x, y, and z vectors is still undefined. ConclusionsThis study showed statistically significant differences in accuracy among the implant analog cast fabrication systems; however; the level of clinical acceptable discrepancy is still undefined. Although further research is needed, this study supports the conclusion that the Polyjet industrial printing system was more accurate than the conventional implant analog gypsum cast.

Interproximal distance analysis of stereolithographic casts made by CAD-CAM technology: An in vitro study

Statement of problemThe accuracy of interproximal distances of the definitive casts made by computer-aided design and computer-aided manufacturing (CAD-CAM) technology is not yet known. PurposeThe purpose of this in vitro study was to compare the interproximal distances of stereolithographic casts made by CAD-CAM technology with those of stone casts made by the conventional method. Material and methodsDentoform teeth were prepared for a single ceramic crown on the maxillary left central incisor, a 3-unit fixed dental prosthesis (FDP) on the second premolar for a metal-ceramic crown, and a maxillary right first molar for a metal crown. Twenty digital intraoral impressions were made on the dentoform with an intraoral digital impression scanner. The digital impression files were used to fabricate 20 sets of stereolithographic casts, 10 definitive casts for the single ceramic crown, and 10 definitive casts for the FDP. Furthermore, 20 stone casts were made by the conventional method using polyvinyl siloxane impression material with a custom tray. Each definitive cast for stereolithographic cast and stone cast consisted of removable die-sectioned casts (DC) and nonsectioned solid casts (SC). Measurements of interproximal distance of each cast were made using CAD software to provide mean ±standard deviation (SD) values. Data were first analyzed by repeated measures analysis of variance (ANOVA), using different methods of cast fabrication (stone and stereolithography) as one within subject factor and different cast types (DC and SC) as another within subject factor. Post hoc analyses were performed to investigate the differences between stone and stereolithographic casts depending upon the results from the repeated measures ANOVA (α=.05). ResultsAnalysis of interproximal distances showed the mean ±SD value of the single ceramic crown group was 31.2 ±24.5 μm for stone casts and 261.0 ±116.1 μm for stereolithographic casts, whereas the mean ±SD value for the FDP group was 46.0 ±35.0 μm for stone casts and 292.8 ±216.6 μm for stereolithographic casts. For both the single ceramic crown and the FDP groups, there were significant differences in interproximal distances between stereolithographic casts and stone casts (P<.001). In addition, the comparisons of DC with SC of stone and stereolithographic casts for the single ceramic crown and FDP groups demonstrated there was statistically significant differences among interproximal distances between DC stereolithographic casts and SC stereolithographic casts only for the FDP group (P<.001). ConclusionsFor both the single ceramic crown and the FDP groups, the stereolithographic cast group showed significantly larger interproximal distances than the stone cast group. In terms of the comparison between DC and SC, DC stereolithographic casts for the FDP group only showed significantly larger interproximal values than those of the SC stereolithographic casts for the FDP group.

Clinical considerations of impression making for edentulous patients

Regardless of the type of impression being made, the tray is the most important part of the impression-making procedure for completely edentulous patients. Dentists have to make use of a combination of rigid, thermoplastic, and resilient materials and control step-by-step procedure from irreversible hydrocolloid impression to definitive cast fabrication. For successful edentulous impression, some considerable clinical tips were guided.

Creating protective appliances for preventing dental injury during endotracheal intubation using intraoral scanning and 3D printing: a technical note

Digital dentistry has influenced many dental procedures, such as three-dimensional (3D) diagnosis and treatment planning, surgical splints, and prosthetic treatments. Patient-specific protective appliances (PSPAs) prevent dental injury during endotracheal intubation. However, the required laboratory work takes time, and there is the possibility of tooth extraction while obtaining the dental impression. In this technical report, we utilized new digital technology for creating PSPAs, using direct intraoral scanners and 3D printers for dental cast fabrication.

Freeze cast fabrication of porous ceramics using tert-butyl alcohol–water crystals as template

Tert-butyl alcohol (TBA)–water (H2O) crystals are used as template to fabricate aligned porous alumina with special pore structures. Alumina slurries were prepared using TBA–H2O mixtures, which could undergo continuous crystallization by unidirectional freezing. The pore shape of porous alumina constantly changed from lamellar to snowflake, dendritic, needle-like, and hexagonal with the increase in the TBA content in alumina slurries. The hexagonal porous structure obtained by pure TBA slurry exhibited the best mechanical properties, whereas the mixture structure with irregular pore walls showed the worst, exhibiting inferior properties to lamellar pore structures.

Wax Lining in an Impression Tray and Accuracy in Gypsum Cast Fabrication.

Controversy exists as to whether lining a metal-perforated impression tray with wax will yield a distorted irreversible hydrocolloid impression. Two current textbooks have completely different recommendations, but there is no evidence to support either theory. This project evaluates distortion in gypsum casts that have been prepared from wax-lined and unlined metal impression trays.The purpose of this study was to assess the influence of wax on the border and in the palate of metal-perforated impression trays on the dimensional stability of the resulting irreversible hydrocolloid impression. A dentaform was prepared with marks on the cusp tips of teeth 6 and 11 and distobuccal cusps of teeth 2 and 15. Using a standard maxillary rim lock impression tray, alginate impressions were made using a dentaform with no wax lining, wax lining the border of the tray, and wax lining the border and the palate (n = 10). Casts were randomized. Six measurements were taken using a stereographic measuring microscope, from tooth #6 to #11, #11 to #15, #15 to #2, #2 to #6, #6 to #15, and #2 to #11. An acrylic template was used to position the cast in a reproducible position on the microscope. Trays lined with wax on the border and the palate yielded casts with significantly different dimensions when compared to those poured from unlined or border-lined trays (p < 0.05). Casts produced from unlined and border-lined trays were not significantly different in dimension from the dentaform (p > 0.05). There is no difference between the metal tray with no wax, the metal tray with a wax around the border, and the dentaform. The clinician can make irreversible hydrocolloid impressions using wax on the periphery or without wax on the periphery and feel confident that the impression has not been compromised in its ability to accurately reproduce the maxillary arch when used. Caution should be exercised when adding wax to the palate of the impression tray.

A technique for changing the shade of a custom-made ocular prosthesis

Digital imaging is simple, decreases treatment time, and requires minimal artistic skills compared to the irispainting technique for making custom-made artificial eyes. However, the reproducibility of the iris shade may vary as a result of the quality of the paper used, the printer inks, and the amount of monopoly syrup added. A mismatched iris shade will require repeating the entire treatment procedure, including custom tray preparation, impression making, cast fabrication, and wax pattern evaluation. This technique provides a method to correct a mismatched iris shade in the same appointment without the need to repeat the entire procedure. The technique

Comparison of accuracy and reproducibility of casts made by digital and conventional methods

Statement of problemLittle peer-reviewed information is available regarding the accuracy and reproducibility of digitally fabricated casts compared to conventional nondigital methods. PurposeThe purpose of this in vitro study was to compare the accuracy and reproducibility of a digital impression and cast fabrication with a conventional impression and cast fabrication. Material and methodsConventional impressions were made via a 1-step single viscosity technique with vinyl siloxanether material of a typodont master model, and conventional casts were cast from dental stone. Digital impressions were obtained with a digital scanner, and digital stereolithographic models were printed. The typodont and fabricated casts were digitized with a structured light scanner and saved in surface tessellation language (STL) format. All STL records were superimposed via a best-fit method. The digital impression and cast fabrication method was compared with the conventional impression and cast fabrication method for discrepancy, accuracy, and reproducibility. The Levene test was used to determine equality of variances, and a 1-way ANOVA was conducted to assess the overall statistical significance of differences among the groups (n=5, α=.05). ResultsNo significant statistical difference was found between the digital cast and conventional casts in the internal area or finish line area (P>.05). In addition, there was no statistically significant difference between these 2 techniques for a fixed dental prosthesis or single crown (P>.05). However, statistically significant differences were observed for overall areas of the casts in terms of accuracy (P<.01) and reproducibility (P<.001). Digital impression and cast fabrication were less accurate and reproducible than conventional impression and cast fabrication methods. ConclusionsNo statistically significant difference was found between the digital cast and conventional cast groups in the internal and finish line areas. However, in terms of the reproducibility and accuracy of the entire cast area, the conventional cast was significantly better than the digital cast.