1055 D3000 new imprint Word template Vol 13, No 1 (2025) ISSN 2167-8677 (online) DOI 10.5195/d3000.2025.1055 http://dentistry3000.pitt.edu 3D Printed Cast Is more Accurate than Conventional Stone Cast for Single Tooth Supported Fixed Prosthesis AlNamel Hasanen Ali College of Den*stry, University of Basrah Iraq Abstract Objec0ve: Studying the clinical adaptaFon of the crown in relaFon to the finished line of the prepared abutment and assessing the fit and precision of single unit fixed dental prosthesis made on digitally printed posiFve replica casts that created by printers depending on digital intra oral scanning by using filament material of resin material were the goals of this in vitro invesFgaFon. Materials and Methods: AQer acquiring digital virtual casts through intraoral scanning of the prepared teeth using a 3Shape trios 4 intraoral scanners, ten digitally printed posiFve replica casts were created using a3D printers depending on digital intra oral scan- ning. The master model was created from filament material of resin material. Ten Conven- Fonal type 3Stone were used to from convenFonal stone cast (CS), final impression was made from dual viscosity impressions material. Every fixed dental prosthesis (FDP) was made using a DenFum 5-axis milling machine. A two-way ANOVA was conducted to characterize the whether the deference between groups was significant or not, 3D analysis soQware was used to superimpose the milled FDPs' intaglio surface and master model. Also post hoc analysis, and Tukey honestly significant difference test was employed. Results: The internal and marginal root mean square (RMS) values of the two groups (three dimensional printed and convenFonal stone cast) were significantly differed, according to a two-way ANOVA. Open Access Cita%on: Ali AH. (2025) 3D Printed Cast Is More Accurate than on Conven%onal Stone Cast for Single Tooth Sup- ported Fixed Prosthesis. Den%stry 3000. 1:a001 doi:10.5195/d3000.2025.1055 Received: September 21, 2025 Accepted: September 27, 2025 Published: November 4, 2025 Copyright: ©2025 Ali AH. This is an open access ar%cle licensed under a Crea%ve Commons ATribu%on Work 4.0 United States License. Email: Hasanen.muhsen@uobasrah.edu.iq Introduc)on Accurate prosthesis fabrication requires precise castings. Other kinds of casts could be considered as substitutes for conven- tional type 3 stone cast if dental clinics regu- larly used digital images acquired with an in- traoral scanner. The 3D-printed cast is one such option [1]. The Citness of the margin and internal portion of a dental restoration spe- cially Cixed dental prosthesis determines its quality. To provide a precise Cit, accurate re- production is necessary. Therefore, accuracy is crucial for creating impressions and copies [2,3]. Intra oral scan of the teeth and associ- ated intra oral structure by using an in- traoral scanner or the traditional technique of (elastomeric impression) can be used to create deCinitive dental master casts [4]. For many years, stone casts have been utilized for prosthetics, diagnosis, and treatment. They are vulnerable to damage and fracture and furthermore, because they are heavy, they are challenging to store. These issues can be avoided with digitally printed positive replica casts that are acquired from a digital scan to the intra oral structure. They can be sent digitally and are stored in a digital for- mat [5,6]. After taking an imprint (intra orally), there is no need to create a deCinitive cast because the data are taken straight from the intra oral cavity by digital scan [7,8]. DeCinitive dental casts are still necessary for certain pros- thetic treatments [9,10] but by using sub- tractive or additive manufacturing, 3D digi- tal virtual casts can be used to create deCinitive and accurate dental casts. The technique of fabricating prostheses has been made simpler and more accurate by subtrac- tive manufacturing (3D printing dental cast) [11,12]. However, due to the milling ma- chine's restricted axes, it is challenging to replicate complicated geometries and under- cuts with this manufacturing method [13]. Additionally, due of the milling bur's diame- ter, this approach produces a lot of waste and may result in inaccuracy (known as drill compensation) [14,15]. Additive manufac- turing, also referred to as 3D printing, on the other hand, develops the intended shapes layer by layer after converting the planned CAD Ciles into slice data [16,17]. Features like undercuts and intricate interior forms can be produced with little material waste [17,18]. 3D Printed Cast Is more Accurate than ConvenFonal Stone Cast for Single Tooth Supported Fixed Prosthesis Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.1055 http://dentistry3000.pitt.edu 2 Additionally, multiple goods can be pro- duced at the same time. Due to these bene- Cits, 3D printers are becoming more and more popular in the prosthodontic Cield. Fur- thermore, 3D printers are now less expen- sive because the original patent for the con- cept has expired [19]. The photopolymerization process is used in digital printing. On the whole platform, the 3D printer printing a single image as a layer concurrently. Because all layers are exposed simultaneously, DLP can thereby shorten printing times [20]. Using high quality three diamantine printer affects accuracy of par- enting [21]. Furthermore, it has been noted that the DLP technique produces diagnosis casts with greater accuracy than other 3D printer kinds [22]. Currently, the primary applications of 3D printers are the creation of surgical guides and orthodontic casts for dental implant procedures. They are antici- pated to be utilized more frequently, never- theless, to produce deCinitive castings for prosthodontics as well as prosthetics. The precision of 3D-printed orthodontic diagnos- tic castings has been assessed in studies. Nevertheless, there aren't many studies on digitally printed positive replica casts were created using a3D printers depending on digital intra oral scanning (FDP). Thus, the objective of this in vitro investigation was to assess the accuracy of 3D-printed casts in comparison to a traditional stone cast (CS) and the marginal and internal Cit of FDPs made on a 3DP. Materials and Methods A single unit FDP was abutted by the maxil- lary right Cirst molars utilizing a Cilament resin typodont (AG-3 ZPVK; Frasaco GmbH). The standard abutment preparation type was full crown preparation (360 degree, 1mm with margins of chamfer type). The created printed cast as a master model made of Cilament epoxy resin duplicated ither from intra oral scan or by scan to the conventional cast made by conventional impression by us- ing an optical scanner (3Shape TRIOS4 4 ad- vance wireless intraoral scanner) with a 6- mm accuracy. Metal rim look stock tray (Mendcy, Italy) were used with heavy body silicon (Zemach, Germany) for primary impression making, after the study cast fabrication, it was lay- ered by 1 mm baseplate wax as spacer and acrylic non perforated special tray was fabri- cated, Cinished and painted with adhesive material to provide mechanical attachment to the impression material. dual viscosity im- pressions were used (10 minutes according to the manufacturer's instruction to ensure for full polymerization) the tray impression was moved with the snap out removed to fabricate ten master model by purring the Cinal impression and cast creating according to the manufacturer's speciCications [22], it was then stored in an incubator for 8 hours at 23°C to control water evaporation and prevent dimensional changes. Type III dental stone (Fuji Rock; GC) was poured into the tray, and the stone cast separated from the impression after 45 minutes to ensure full polymerization. Following a 8-hour storage period, the stone castings were digitalized using a reference scanner and saved as a standard tessellation language (STL) Cile (CS group). A trained clinician created ten three dimen- sional printed casts (3DP group) by scanning the master model with an intraoral scanner. Using the pertinent exported STL Ciles (digi- tal virtual casts), three dimensional printed casts were produced using a three-dimen- sional dental model printer (3Dent; Envi- sionTEC GmbH). In around three hours, the 3D printer created ten castings at a 50 mm resolution. These cast then scanned using the digital intra oral scanner, and the ana- lytic software (STL Cile) was stored. The sin- gle-unit FDPs were built using CAD-CAM software (Dentium milling) throe an STL Cile, the crowns were fabricated to the collected data include the scanning of the conven- tional cast data and intra oral scan. Using a 5- axis milling machine (DWX-50; Roland DG Corp), the single-unit FDPs were produced from a polyurethane block (innoBlanc model; innoBlanc GmbH). Following milling, the intaglio of the Cinished single-unit FDPs was captured by a reference scanner and stored as an STL Cile. Using 3D analysis tools, all STL Ciles were reduced to the region of in- terest, eliminating defects and artifacts for precise superimposition (Geomagic Verify 2015; Geomagic GmbH). The single unit FDPs intaglio scan data and the master model data were automatically aligned be- fore being overlaid. For precise alignment, the best-Cit alignment the acceptance varie- ties were then strongminded in this way: the maximum value/the minimum value (±10 mm); and the overall deviation was com- puted using standards from a dye chart. Root mean squares (RMSs) were used to quantify the dimensional differences between the dig- italized single unit FDPs' intaglio surface data and the master model [23]. RMSs were computed using the subsequent formula: Root mean squares (RMSs) where xi is the measurement argument of the master model and n is the quantity of the measured points. In this study, an exact 3D match was indi- cated by a low RMS score. To measure the 3D data, the castings were also separated into the mesial and distal sides using a line that split each abutment's mesiodistal region in half, and between the marginal and interior sections using a line that curved sharply to- wards the axial wall (Figures 1 and 2). The statistical analysis was carried out using statistical software (IBM SPSS Statistics, v22.0; IBM Corp.). To Cind out if the kind of group and side, as well as how they inter- acted, affected the RMS values, a 2-way ANOVA was employed. To Cind signiCicant differences between the groups, the post hoc Tukey HSD honestly signiCicant difference (HSD) test (a=.05) was used. Results The mean RMS and standard deviation val- ues for internal and marginal disagreement are displayed in Table 1. The internal (en- tire) RMS values in CS and 3DP were 25.55 mm and 53.77 mm, respectively, whereas the marginal (entire) RMS values were 34.88 mm and 43.56 mm. Furthermore, it was shown that the side accuracy between 3DP type and cast group had a signiCicant interac- tion (P=0.009). SigniCicant differences were found between groups (P<0.001) and between side (P=0.007) internal RMS values, as shown in Table 2. Nevertheless, the interaction effect between the groups and sides type (P=0.571) and the marginal RMS values between on the sides (P=0.762) were not signiCicant. As seen in Table 3, the marginal and internal RMS val- ues for 3PD were signiCicantly higher than those for CS (P<0.001) according to the post hoc Tukey HSD test. Color difference maps (Cigure 3) showed the variations between the FDPs' intaglio sur- face and the master model. The inside part of 3DP is shown in light blue on the vertical slopes (negative discrepancies) and dark yellow on the occlusal surfaces (positive dis- crepancies). Discussion Since disparities in the marginal and internal Cits between the sides (mesial side and distal side) and groups (CS and 3DP) were found, the study's Cindings supported the rejection of the null hypothesis. One signiCicant devel- opment for dental ofCices is the use of in- traoral scanners. Stone cast alternatives, in- cluding 3D-printed casts, will be needed as this technique gains traction. In this work, FDPs created on stone casts and FDPs made on 3D-printed castings were compared for internal and marginal Cit. The entire digital process—from getting the scan to making the prosthesis—was con- trasted with the conventional process in this study. Since the precision of the casts was compared in earlier studies, mistakes in the prosthesis fabrication process were elimi- nated [8,11,23]. As a result, the complete 3D Printed Cast Is more Accurate than ConvenFonal Stone Cast for Single Tooth Supported Fixed Prosthesis Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.1055 http://dentistry3000.pitt.edu 3 fabrication process was not evaluated. Be- cause the current investigation was carried out in a standardized environment, the over- all number of manufacturing errors at every stage of the workClow was reduced. Both 2D and 3D approaches can be used to measure the prosthesis' internal and mar- ginal Cit. The replica, direct view, and cross- sectioning techniques are all part of the 2D measurement strategy. One These tech- niques quantify the amount of variation in pictures captured with a stereomicroscope or similar instruments. The incapacity of 2D measures to assess discrepancy at multiple sites is their primary drawback. In contrast, the 3D analysis measures the thickness of the inside and outside of virtual space nu- merous times. Its use of a color map to visually represent the entire discrepancy is advantageous, as no information is lost that might arise from measuring just one area [24]. The tempera- ture differential between the oral cavity and the surrounding air causes thermal contrac- tion in silicone impression materials [24]. Because the imprint was created at ambient temperature, these errors were not repli- cated in our investigation. Consequently, a clinical impression was less accurate than a standard impression control. According to Mously et al., the internal gap increased as the spacer thickness setting increased. Addi- tionally, several studies have demonstrated that the spacer thickness setting affects how well the prosthesis Cits [2,3,25]. To get an exact RMS result in the current ex- periment, the spacer thickness was set to 0. Both the internal and marginal Cits are inClu- enced by the prosthesis's material [25]. In this investigation, a polyurethane block was utilized as the prosthetic material. Because this block is machined to the same size as the desired form, it has the advantage of reduc- ing the issue of expansion and shrinkage dur- ing milling [18,25]. Furthermore, because it does not reClect light like metal, zirconia, or ceramic do, it is perfect for scanning and ap- propriate for 3D evaluation. A prosthesis made using CAD-CAM technology has had its marginal accuracy assessed [4,26]. The range of marginal discrepancies that are clin- ically important is unknown, and there are differences in the ranges of marginal Cit that are clinically acceptable. In a 5-year clinical study involving 1000 restorations, McLean and von Fraunhofer determined that the maximum permissible marginal gap was 120 mm. Furthermore, the deCinition of clinically adequate internal Cit values, which have been reported using a range of techniques, is still up for debate [25,26]. The present study also revealed that the RMS value of 3DP (53.77 mm) was higher than that of CS (25.55 mm) in the interior (entire) area, as indicated in Table 1 and depicted in Figure 3. According to Anadioti et al., a pros- thesis built using the 3D printing method of stereolithography (SLA) die had a substan- tially better internal Cit than one made using a stone die. These numerical values and re- sults are comparable to those of the current investigation, even though the prosthesis material, measurement techniques, and 3D printing technology utilized to create the cast varied. Table 1 indicates that the current study found that in the marginal (entire) area, the RMS value of 3DP was greater than that of CS. This is consistent with Anadioti et al.'s Cindings [19,26], who concluded that a prosthesis manufactured on a stone die had a somewhat better Cit than one manufac- tured on a SLA die. Numerous factors, such as postprocessing, materials, manufacturer setting parameters, and 3D printing proce- dures, affect the resolution and accuracy of 3D printers. For example, the SLA process is affected by horizontal resolution, which is determined by the diameter of the laser beam, and vertical resolution, which is de- pendent on layer thickness [27]. Moreover, changing the setup parameters leads to var- ying machining accuracy and build timeframes, which may result in residual in- ternal tension during the post-curing phase and perhaps distort the prosthesis. When compared to the CS group, the 3DP group's greater RMS values in the internal and mar- ginal areas are caused by the 3D printer's formative processes. In a 3D printer, materi- als are deposited toward the axis layer by layer. This layer-by-layer technique creates a stair-step impression on the object's surface [27,28]. As a result, the product may have di- mensional errors or uneven surfaces [28]. Furthermore, because the DLP technique uti- lized in this study is based on a bottom-up projection in which the build platform moves higher, a polymerized layer is sandwiched between the resin vat and the layer that came before. When the build platform is re- moved from the vat during the construction process, the coagulated material may attach Cirmly to the resin and deform the item. [29]. The current study evaluated cast discrepan- cies by splitting the internal and marginal Cit into mesial and distal sides in order to sepa- rate the data and appropriately measure the castings. The mesial and distal side RMS val- ues in the marginal and internal areas were not statistically different, except for the 3DP group's internal RMS values (Figure 4). This result appears to be due to the qualities of the material used in the 3D printer. A pho- topolymerization approach is required for resin, one of the materials used in the DLP process. Photopolymerization-induced ma- terial shrinkage can result in residual ten- sion, skewing, or distortion in the Cinal product. The RMS values on the distal side appear to be higher because the strain is di- rected toward the mesial side (Figure 4). Ac- cording to an analysis of study results, pros- theses made from stone casts Cit better than those made from 3D-printed castings. The difference was barely noticeable as all Cind- ings fell below the clinically acceptable range (<120 mm) [30]. These Cindings strengthen the case for using 3D-printed casts for long- term prosthesis. However, because various factors in the mouth cavity inCluence the dig- italization and impression processes, clinical trials should be conducted to assess 3D printing. Conclusion The following deductions were made consid- ering the results of this in vitro investigation: 1) The 3DP group's internal and marginal RMS values were noticeably greater than the CS groups. 2) Nonetheless, the internal and marginal f val- ues for both groups were within the clini- cally acceptable range (<120 mm). 3D printer accuracy needs to be further im- proved. References 1. Kuhn K, Ostertag S, Ostertag M, Walter MH, Lu- thardt RG, RudolphH. Comparison of an analog and digital quantitative and qualitative analysis for the Hit of dental copings. Compute Biol Med 2015; 57:32-41. 2. Mously HA, Finkelman M, Zandparsa R, Hirayama H. Marginal and internal adaptation of ceramic crown restorations fabricated with CAD/CAM technology and the heat-press tech- nique. J Prosthetic Dent 2014; 112:249-56. 3. Kale E, Seker E, Yilmaz B, O] zcelik TB. Effect of cement space on the marginal Hit of CAD-CAM-fab- ricated monolithic zirconia crowns. J Prosthetic Dent 2016; 116:890-5. 4. 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Figure 1. Scanning image analysis for single unit Cixed dental prosthesis. 3D Printed Cast Is more Accurate than ConvenFonal Stone Cast for Single Tooth Supported Fixed Prosthesis Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.1055 http://dentistry3000.pitt.edu 5 Figure 2. Single unit FDPs intaglio scan data subdivisions. Table 1. RMS values for Cixed partial dentures' internal (complete) gap and marginal (complete) discrepancy (mm). The area groups N (RMS) (micro m) Mean /Standard Deviation p-value discrepancy of the Marginal CS 10 34.88/3.4 3DP 10 43.56/2.6 Inferior gap CS 10 25.55/2.1 3DP 10 53.77/2.5 0.001 Table 2. Mean and ±SD between groups and between sides (2-way ANOVA). groups N Mesial Mean and Standard Devia- tion Distal Mean and Standard Deviation p-value Conventional cast Three D printed 10 27.66/2.4 28.77/2.4 10 52.67/4.3 57.88/4.5 0.001 3D Printed Cast Is more Accurate than ConvenFonal Stone Cast for Single Tooth Supported Fixed Prosthesis Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.1055 http://dentistry3000.pitt.edu 6 Table 3. Mean and ±SD between groups and between sides (post-hoc Tukey HSD test). groups N Mesial Mean and Standard Devia- tion Distal Mean and Standard Deviation p-value Conventional cast Three D printed 10 39.66/2.4 39.77/2.4 10 54.67/4.3 54.88/4.5 0.001 Figure 3. Maps showing differences in color. A, CS internal Cit. B, 3DP's internal Cit. C, CS's marginal Cit. D, 3DP's marginal Cit. 3DP stands for 3D-printed cast; CS stands for traditional stone cast. A B C D 3D Printed Cast Is more Accurate than ConvenFonal Stone Cast for Single Tooth Supported Fixed Prosthesis Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.1055 http://dentistry3000.pitt.edu 7 Figure 4. Color difference maps of inconsistencies. A: The mesial side of the CS's interior region. B: distal side in 3DP's interior area. C: mesial side in CS's interior area. D represents the distal side of the 3DP's internal area. 3DP stands for 3D-printed cast, while CS is for conventional stone cast. A B C D