Saudi Cultural Missions Theses & Dissertations
Permanent URI for this communityhttps://drepo.sdl.edu.sa/handle/20.500.14154/10
Browse
3 results
Search Results
Item Restricted ANALYSIS OF ACCURACY AND MECHANICAL PROPERTIES OF 3DPRINTED POLYMERIC DENTAL MATERIALS(Boston University, 2024) Alshaibani, Raghdah; Fan, Yuwei; Giordano II, Russell; Yamamoto, HideoObjectives: The objective was to investigate the accuracy, storage stability, and mechanical properties of 3D-printed polymeric dental materials. Materials and Methods: Three completely dentate models, two maxillary and one mandibular each with their respective die, and three implant models were designed using dental CAD software (3SHAPE DENTAL SYSTEM). A horseshoe-shaped solid base with a posterior horizontal bar was utilized. The models were printed based on the manufacturer's instructions for four weeks using six printers with the corresponding recommended resin materials: Carbon M2 (DPR10), HeyGears A2D4K (Model HP UV2.0), Stratasys J5 (MED610), Stratasys Origin One (DM200), Envision One (E-Model LightDLP), and Asiga Pro4K (VeriModel) with a standard layer thickness of 50 μm (N=72). The models were scanned after printing using Sirona inEOS X5 scanner, while the implant models were scanned using a CT scanner (GE Phoenix V|tome|x metrology edition). The full arch models were randomly assigned to three groups of storage conditions: cold environment (LT, 4 ± 1°C), hot and dry environment (HT, 50 ± 2°C), and room temperature (RT , 25 ± 2°C, serving as the control). Each group was kept under the designated conditions and scanned at 1, 2, 3, 4, and 8 weeks. The generated STL files were imported into a 3D inspection software for comparison with the original STL files. Four sets of reference points (central fossa of first premolars and central fossae of second molars) were selected to determine six distances of inter-arch segments, from which the inter-arch distance trueness and precision deviation were measured. For the second part of the study, maxillary Lucitone Digital Print denture base (DB) (N=5), maxillary Lucitone IPN 3D Premium anterior and posterior teeth (N=6), and maxillary Keystone Keysplint Soft Clear occlusal splint (N=5) were printed using two printers (Carbon M2, Asiga Max UV) with a standard layer thickness of 50 μm for denture base and teeth, and 100 μm for the occlusal splint. The tolerance threshold was set to 50 μm for Lucitone IPN and 100 μm for Lucitone DB and Keysplint Soft. In-tolerance percentage and deviation RMS were obtained and analyzed with multivariate least square mean linear regression using JMP Pro 17 (SAS, Cary, NC) to identify significant effects (α=0.05). The third part investigated the mechanical properties of Lucitone DB and IPN using 2 printers (Carbon M2, Asiga Max UV) as follows: flexural strength (N=10) using a three-point bend test, fracture toughness (N=10), creep (N=5), Vickers hardness test (N=15), surface roughness (N=15), while Shore A hardness (N=15) and tensile strength (N=10) were performed for Keysplint Soft Clear. Data were analyzed using one-way and multivariate least square mean linear regression followed by Tukey’s HSD test using JMP Pro 17 (SAS, Cary, NC) to identify significant effects (α=0.05). Results: The in-tolerance percentage varied significantly among printers, with Carbon M2 (CAB) showing the highest values. Stratasys (J5) displayed the highest accuracy in term of precision, while HeyGears A2D4K (HGS), Carbon M2 (CAB), and Stratasys (J5) exhibited the highest accuracy in term of trueness. The inter-molar segment showed the highest deviation. No significant difference was observed in in-tolerance percentage across different print weeks except for week 2 in one printer (Stratasys Origin1). CAB exhibited a higher in-tolerance percentage for the DB than Asiga Max UV (ASG), with the fitting surface having the highest in-tolerance percentage. IPN anterior teeth had a higher in-tolerance percentage than posterior teeth, with ASG showing a higher value than CAB. No statistically significant difference was found in the in-tolerance percentage of Keysplint Soft Clear between ASG and CAB. Resin printed using ASG demonstrated higher flexural strength, Vickers hardness, and creep, while resin printer using CAB exhibited higher fracture toughness, with no significant difference in surface roughness between the two printers. Lucitone IPN had higher flexural strength and Vickers hardness, surface roughness , and lower creep and fracture toughness than Lucitone DB. CAB Keysplint Soft had higher tensile strength than ASG, with no statistically significant difference in Shore A hardness between the two printers. Conclusion: Model dimension deviations were impacted by storage conditions and the specific printer utilized, with high-temperature storage exhibiting the least stability. However, no significant difference was noted between low and room temperature storage conditions. Carbon M2 exhibited the highest level of accuracy. The of 3D-printed denture bases and denture teeth varied across different printers. Conversely, no significant difference in accuracy was observed for a soft occlusal splint between two printers. Materials printed using different printers showed statistically significant different mechanical properties.32 0Item Restricted Three-Dimensional Accuracy of Printed Alveolar Casts(Saudi Digital Library, 2023-08-31) Alghamdi, Mohanned; Papaspyridakos, PanosObjective: The purpose of this in-vitro study was to evaluate the accuracy of 3D printed alveolar casts fabricated with three different 3D printers from digital scans on a reference typodont in the scenario of a maxillary veneer, two crowns, fixed dental prostheses and onlay. Material and Methods: A reference cast, prepared using a Kilgore K-2 typodont with various tooth preparations, was scanned using a Trios4 intra-oral scanner. This created an STL file that served as a digital reference for superimposition and the design of a digital alveolar cast. The digital cast was designed using (Exocad Dental CAD® 3.1 Rijeka) software, including movable dies and a cast base. This design was then exported as an STL file for 3D printing. Three 3D printers (Carbon DLS, Straumann P30+, Formlabs Form3b+) were used to print the alveolar casts, and all were cleaned and post-cured as per the manufacturers' instructions. The printed casts were then digitized using the same intra-oral scanner, and the resultant digitized casts were exported as STL files. Finally, the 3D deviations of each printed cast were calculated by superimposing the cast STL files onto the original digital reference cast using Geomagic Control X software. The software then determined the root mean square error for each clinical scenario. Results: The study observed significant differences between specific pairs of dental restorations in each category except for the veneers. For onlays, Carbon showed significantly lower RMS error compared to Formlabs® Form3b+ (P<0.001). In post-hoc comparisons, between Formlabs® Form3b+ and Straumann® P30+ (P=0.044). Similarly, Carbon exhibited significantly lower RMS error in the gold crown category than Formlabs® Form3b+ (P<0.001). For ceramic crowns, both Formlabs® Form3b+ and Carbon had significantly higher RMS error than Straumann® P30+ (P=0.004 and P=0.010, respectively). In fixed dental prostheses (FDP), Carbon had significantly less deviation than both Straumann® P30+ and Formlabs® Form3b+ (P<0.001). Notably, no significant differences were found among the veneers' RMS error values (P=0.055). Conclusion According to this study, the Continuous Liquid Interface Production (CLIP) printer exhibited higher accuracy compared to the Stereolithography (SLA) printer for onlays (P<0.001), gold crowns (P<0.001), and fixed dental prostheses (P<0.001). Also, the Continuous Liquid Interface Production (CLIP) printer exhibited higher accuracy compared to the Digital Light Processing (DLP) for fixed dental prostheses (P<0.001). On the other hand, the Digital Light Processing (DLP) exhibited higher accuracy compared to Continuous Liquid Interface Production (CLIP) the Stereolithography (SLA) printer for ceramic crowns (P=0.010), (P=0.004) respectively18 0Item Restricted Effect of Finishing and Polishing Techniques on the Fit Accuracy and Dimensions of Conventional and CAD-CAM Removable Partial Denture Frameworks(2023-07-13) Altoman, Majed; Kattadiyil, MathewRapid advancements in computer-aided design and computer-aided manufacturing (CAD- CAM) in removable dental prosthodontics have offered new modalities for fabrication of removable partial denture frameworks. The standard tessellation language (STL) files of the scans are used to digitally design the removable partial denture (RPD) framework, which are then printed in cobalt-chromium (Co-Cr) alloy and finished and polished according to manufacturers’ recommendations. There are few studies compare the fit accuracy of the cast DPD framework versus the CAD CAM RPD frameworks which found that CAD-RP frameworks exhibited the highest discrepancies, using different methods of evaluation. Good fit between the denture base and the supporting tissue, the intimate contacts between the teeth and framework components improve support, stability and retention and are critical to the satisfactory outcome for the RPD patient. Currently, no study has evaluated the fit accuracy of 3D printed removable partial dentures (RPD) after finishing and polishing techniques based on the manufacturer’s protocol. Purpose: The purpose of this study was to: 1) Compare the effects of finishing and polishing techniques on the overall fit accuracy and dimension of conventional versus CAD-CAM fabricated RPD frameworks. 2) Evaluate the loss of metal from various components of the RPD framework after finishing and polishing. Material and methods: A maxillary arch 3D printed model with a Kennedy class III modification I situation was fabricated as a master cast. The master model was scanned and used to compare the fit and accuracy of the RPD frameworks. The master cast were made and divided into 4 groups based on fabrication method: group I, lost-wax technique (conventional technique), group II, CAD-printing, group III, CAD-printing from stone cast, and group IV, lost-wax technique from resin-printed model. RPD frameworks were fabricated in cobalt-chromium alloy. The finishing and polishing techniques of the RPD frameworks using different methods were performed based on manufacturers’ recommendation. All RPD frameworks were scanned, and accuracy of fitting and metal thickness loss of various components of the RPD framework were evaluated. All RPD frameworks were evaluated the surface roughness based on SEM analysis. Results: All RPD frameworks were evaluated before and after finishing and polishing techniques based on manufacturers’ recommendation. Color mapping revealed state statistically significant between cast RPD framework versus 3D printed frameworks major connectors, reciprocal and retentive arms among the groups after finishing and polishing techniques based on manufacture’s recommendation (P < 0.05). There was statistically significant difference between the conventionally cast framework groups (LWT versus LWTR) compared to the 3D-printed framework groups (CAD-RP versus CAD-RPS) (P < 0.001). The biggest gap (0.33 mm ± 0.20 mm) was observed with the guide plates with the printed frameworks (groups II and III). The overall metal loss after using different finishing and polishing techniques revealed statistically significant differences in metal loss between the conventional polishing and finishing technique of cast RPD frameworks (P < 0.001) compared to the D-Lyte polishing and finishing technique of 3D printed frameworks particularly in the occlusal rest and the junction with the proximal plate. The conventional finishing and polishing technique showed more surface roughness than D- lyte finishing and polishing technique based on scanning electron microscope (SEM) analysis. Conclusion: Within the limitations of the present study, although both conventional cast RPD and 3D printed frameworks were found to be clinically acceptable, the conventionally processed RPD groups revealed better overall fit and accuracy after finishing and polishing. The conventional cast RPD frameworks showed more metal loss than 3D printed RPD frameworks after finishing and polishing technique and more surface roughness based on SEM analysis.32 0