Saudi Cultural Missions Theses & Dissertations
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Item Restricted The effect of surface treatment on the adhesive strength of chairside hard liners to dental polymers used for the conventional, additive, and subtractive fabrication of complete dentures(The Ohio State University, 2022) Aldosari, Abdullah Mohammed A; Azer, Shereen S.; Schricker, Scott R.; Lee, Damian J.Objectives: The aim of this in vitro study was to evaluate the tensile bond strength of two hard denture relining materials on denture bases fabricated from conventional, subtractive, and additive polymers. In addition, this study assessed the effect of a polymer to resin primer on the tensile bond strength of hard denture liners to different denture bases. Methods: A total of 120 hard relined denture base samples were fabricated, 40 per denture base group (Lucitone 199, Ivo Base CAD, and NextDent Denture 3D+). For each denture base group 20 samples were hard relined with one of two chair side hard denture liner (GC Reline, MucoHard). Among the hard reline groups, 10 of each group was primed with a composite to PMMA primer (Visio.link). All samples underwent thermocycling. The adhesive strength was evaluated through tensile testing. The surface contact angle was measured on each denture group sample to evaluate the wettability of the material. The data was analyzed using Inverse-variance weighted linear regression. Results: In this study overall the denture bases relined with MucoHard denture liner had significantly higherbond strength than the GC reline groups (P<0.016). The highest tensile bond strength was achieved by combining MucoHard denture liner and primed 3D printed denture base, followed by the non-primed conventional denture base, and non-primed milled denture base to MucoHard denture liner. The surface primer used in this study (Visio.Link primer, Bredent UK Ltd. Chesterfield, UK.) had a significant effect on the tensile bond strength of all tested groups (P<0.0003). However, the primer only positively influenced the bond strength of the 3D printed denture base to MucoHard denture liner, while the other groups were inversely affected. Conclusion: There was no significant difference in the tensile bond strength of chairside denture liners to denture bases fabricated using additive, subtractive, and conventional methods (P>0.05). The highest bond strength was achieved with the combination of MucoHard denture liner and primed 3D printed denture bases. MucoHard denture liner has overall significantly higher tensile bond strength in comparison to GC reline. (P<0.016) The primer only positively influenced the bond strength of MucoHard to 3D printed denture bases. The primer significantly alters the wettability of the denture bases.55 0Item 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 0