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Öğe Bond strength of additively manufactured composite resins to dentin and titanium when bonded with dual-polymerizing resin cements(Elsevier Inc., 2023) Donmez, M.B.; Çakmak, G.; Yılmaz, D.; Schimmel, M.; Abou-Ayash, S.; Yilmaz, B.; Peutzfeldt A.Statement of problem: Additively manufactured composite resins for definitive restorations have been recently introduced. The bond strength between these composite resins and different substrates has not been extensively studied. Purpose: The purpose of this in vitro study was to measure the shear bond strength (SBS) between additively manufactured composite resins and dentin and titanium substrates and compare those with the SBS between subtractively manufactured polymer-infiltrated ceramic and the same substrates (dentin and titanium), when different dual-polymerizing resin cements were used. Material and methods: One hundred and eighty cylinder-shaped specimens (Ø5×5 mm) were prepared from 3 materials recommended for definitive restorations: an additively manufactured composite resin (Crowntec [CT]); an additively manufactured hybrid composite resin (VarseoSmile Crown Plus [VS]); and a subtractively manufactured polymer-infiltrated ceramic (Enamic [EN]) (n=60). Specimens were randomly divided into six subgroups to be cemented to the two substrates (dentin and titanium; n=30) with 1 of 3 resin cements (RelyX Universal, Panavia V5, and Variolink Esthetic DC) (n=10). The restoration surface to be bonded was treated according to the respective manufacturer's recommendations. Dentin surfaces were treated according to the resin cement (Scotchbond Universal Plus Adhesive for RelyX Universal, Panavia V5 Tooth Primer for Panavia V5, and Adhese Universal for Variolink Esthetic DC), while titanium surfaces were airborne-particle abraded, and only the specimens paired with Panavia V5 were treated with a ceramic primer (Clearfil Ceramic Primer Plus). SBS was measured in a universal testing machine at a crosshead speed of 1 mm/min. Failure modes were analyzed under a microscope at ×12 magnification. Data were analyzed by using 2-way analysis of variance and Tukey honestly significant difference tests (?=.05). Results: When SBS to dentin was considered, only restorative material, as a main factor, had a significant effect (P<.001); EN had the highest SBS (P<.001), while the difference in SBS values of CT and VS was not significant (P=.145). As for SBS to titanium, the factors restorative material and resin cement and their interaction had a significant effect (P<.001). Within each resin cement, EN had the highest SBS to titanium (P<.001), and within each restorative material, Variolink resulted in the lowest SBS (P?.010). Overall, EN and RelyX were associated with the highest SBS to titanium (P?.013). Mixed failures were predominant in most groups. Conclusions: Regardless of the substrate or the resin cement used, the subtractively manufactured polymer-infiltrated ceramic had higher shear bond strength than the additively manufactured composite resins. The SBS of the additively manufactured composite resins, whether bonded to dentin or titanium, were not significantly different from each other. Regardless of the restorative material, Variolink DC resulted in the lowest SBS for titanium surfaces. © 2023 Editorial Council for The Journal of Prosthetic DentistryÖğe Comparison of wear and fracture resistance of additively and subtractively manufactured screw-retained, implant-supported crowns(Elsevier Inc., 2023) Diken, Türksayar, A.A.; Demirel, M.; Donmez, M.B.; Olcay, E.O.; Eyüboğlu, T.F.; Özcan, M.Statement of problem: Additively manufactured resins indicated for fixed definitive prostheses have been recently marketed. However, knowledge on their wear and fracture resistance when fabricated as screw-retained, implant-supported crowns and subjected to artificial aging is limited. Purpose: The purpose of this in vitro study was to evaluate the volume loss, maximum wear depth, and fracture resistance of screw-retained implant-supported crowns after thermomechanical aging when fabricated using additively and subtractively manufactured materials. Material and methods: Two additively manufactured composite resins (Crowntec [CT] and VarseoSmile Crown Plus [VS]) and 2 subtractively manufactured materials (1 reinforced composite resin, Brilliant Crios [BC] and 1 polymer-infiltrated ceramic network, Vita Enamic [EN]) were used to fabricate standardized screw-retained, implant-supported crowns. After fabrication, the crowns were cemented on titanium base abutments and then tightened to implants embedded in acrylic resin. A laser scanner with a triangular displacement sensor (LAS-20) was used to digitize the preaging state of the crowns. Then, all crowns were subjected to thermomechanical aging (1.2 million cycles under 50 N) and rescanned. A metrology-grade analysis software program (Geomagic Control X 2020.1) was used to superimpose postaging scans over preaging scans to calculate the volume loss (mm3) and maximum wear depth (mm). Finally, all crowns were subjected to a fracture resistance test. Fracture resistance and volume loss were evaluated by using 1-way analysis of variance and Tukey Honestly significant difference (HSD) tests, whereas the Kruskal-Wallis and Dunn tests were used to analyze maximum wear depth. Chi-square tests were used to evaluate the Weibull modulus and characteristic strength data (?=.05). Results: Material type affected the tested parameters (P<.001). CT and VS had higher volume loss and maximum wear depth than BC and EN (P<.001). EN had the highest fracture resistance among tested materials (P<.001), whereas BC had higher fracture resistance than CT (P=.011). The differences among tested materials were not significant when the Weibull modulus was considered (P=.199); however, VE had the highest characteristic strength (P<.001). Conclusions: Additively manufactured screw-retained, implant-supported crowns had higher volume loss and maximum wear depth. All materials had fracture resistance values higher than the previously reported masticatory forces of the premolar region; however, the higher characteristic strength of the subtractively manufactured polymer-infiltrated ceramic network may indicate its resistance to mechanical complications. © 2023 The AuthorsÖğe Effect of analysis software program on measured deviations in complete arch, implant-supported framework scans(Elsevier Inc., 2023) Dede, D.Ö.; Çakmak, G.; Donmez, M.B.; Küçükekenci, A.S.; Lu, W.-E.; Ni, A.A.; Yilmaz B.Statement of problem: Implementation of fabrication trueness analysis by using a recently introduced nonmetrology-grade freeware program may help clinicians and dental laboratory technicians in their routine practice. However, knowledge of the performance of this freeware program when compared with the International Organization for Standardization recommended metrology-grade analysis software program is limited. Purpose: The purpose of this in vitro study was to evaluate the effect of an analysis software program on measured deviations in the complete arch, implant-supported framework scans. Material and methods: A total of 20 complete arch, implant-supported frameworks were fabricated from a master standard tessellation language (STL) file from either polyetheretherketone (PEEK) or titanium (Ti) (n=10). All frameworks were then digitized by using different scanners to generate test STLs. All STL files were imported into a nonmetrology-grade freeware program (Medit Link) and a metrology-grade software program (Geomagic Control X) to measure the overall and marginal deviations of frameworks from the master STL file by using the root mean square (RMS) method. Data were analyzed by using the two 1-sided paired t test procedure, in which 50 µm was considered as the minimal clinically meaningful difference (?=.05). Results: When overall RMS values were considered, the nonmetrology-grade freeware program was not inferior to the metrology-grade software program (P<.05). When marginal RMS values were considered, the nonmetrology-grade freeware program was inferior to the metrology-grade software program only when PEEK frameworks were scanned with an E4 laboratory scanner (P>.05). Conclusions: The use of the tested nonmetrology-grade freeware program resulted in overall deviation measurements similar to those when a metrology-grade software program was used. The freeware program was inferior when marginal deviations were analyzed on E4 scans of a PEEK framework, which was the only scanner-material pair that led to a significant difference, among the 15 pairs tested. © 2023 The AuthorsÖğe Effect of material and antagonist type on the wear of occlusal devices with different compositions fabricated by using conventional, additive, and subtractive manufacturing(Elsevier Inc., 2024) Ateş, G.; Demirel, M.; Donmez, M.B.; Dayan, S.Ç.; Sülün, T.Statement of problem: Additive (AM) and subtractive (SM) manufacturing have become popular for fabricating occlusal devices with materials of different chemical compositions. However, knowledge on the effect of material and antagonist type on the wear characteristics of occlusal devices fabricated by using different methods is limited. Purpose: The purpose of this in vitro study was to evaluate the effect of material and antagonist type on the wear of occlusal devices fabricated by using conventional manufacturing, AM, and SM. Material and methods: Two-hundred and forty Ø10×2-mm disk-shaped specimens were fabricated by using heat-polymerized polymethylmethacrylate (control, CM), AM clear device resin fabricated in 3 different orientations (horizontal [AMH], diagonal [AMD], and vertical [AMV]), SM polymethylmethacrylate (SMP), and SM ceramic-reinforced polyetheretherketone (SMB) (n=40). Specimens were then divided into 4 groups based on the antagonists: steatite ceramic (SC); multilayered zirconia (ZR); lithium disilicate (EX); and zirconia-reinforced lithium silicate (ZLS) used for thermomechanical aging (n=10). After aging, the volume loss (mm3) and maximum wear depth (?m) were digitally evaluated. Data were analyzed with 2-way analysis of variance and Tukey honestly significant difference tests (?=.05). Results: The interaction between the device material and the antagonist affected volume loss and maximum depth of wear (P<.001). AMH had volume loss and depth of wear that was either similar to or higher than those of other materials (P?.044). When SC was used, CM had higher volume loss and depth of wear than AMV, and, when EX was used, AMD had higher volume loss and depth of wear than SMP (P?.013). SC and ZR led to higher volume loss of CM and AMH than EX and led to the highest depth of wear for these materials, while ZR also led to the highest volume loss and depth of wear of AMD and AMV (P?.019). EX led to the lowest volume loss and depth of wear of AMV and SMP and to the lowest depth of wear of AMH (P?.021). Regardless of the antagonist, SMB had the lowest volume loss and depth of wear (P?.005). Conclusions: AMH mostly had higher volume loss and depth of wear, while SMB had the lowest volume loss, and its depth of wear was not affected by the tested antagonists. ZR mostly led to higher volume loss and maximum depth of wear, while EX mostly led to lower volume loss and maximum depth of wear of the tested occlusal device materials. © 2024 The AuthorsÖğe Fabrication trueness and internal fit of different lithium disilicate ceramics according to post-milling firing and material type(Elsevier Ltd, 2024) Demirel, M.; Donmez, M.B.Objectives: To evaluate whether post-milling firing and material type affect the fabrication trueness and internal fit of lithium disilicate crowns. Methods: A prefabricated cobalt chromium abutment was digitized to design a mandibular right first molar crown. This design file was used to fabricate crowns from different lithium disilicate ceramics (nano-lithium disilicate (AM), fully crystallized lithium disilicate (IN), advanced lithium disilicate (TS), and lithium disilicate (EX)) (n = 10). Crowns, the abutment, and the crowns when seated on the abutment were digitized by using an intraoral scanner. Fabrication trueness was assessed by using the root mean square method, while the internal fit was evaluated according to the triple scan method. These processes were repeated after the post-milling firing of AM, TS, and EX. Paired samples t-tests were used to analyze the effect of post-milling firing within AM, TS, and EX, while all materials were compared with 1-way analysis of variance and Tukey HSD tests (? = 0.05). Results: Post-milling firing reduced the surface deviations and internal gap of AM and EX (P ? 0.014). AM mostly had higher deviations and internal gaps than other materials (P ? 0.030). Conclusions: Post-milling firing increased the trueness and internal fit of tested nano-lithium disilicate and lithium disilicate ceramics. Nano-lithium disilicate mostly had lower trueness and higher internal gap; however, the maximum meaningful differences among tested materials were small. Therefore, the adjustment duration and clinical fit of tested crowns may be similar. Clinical Significance: Tested lithium disilicate ceramics may be suitable alternatives to one another in terms of fabrication trueness and internal fit, considering the small differences in measured deviations and internal gaps. © 2024 The Author(s)Öğe Fabrication trueness and marginal quality of additively manufactured resin-based definitive laminate veneers with different restoration thicknesses(Elsevier Ltd, 2024) Çakmak, G.; Donmez, M.B.; Yılmaz, D.; Yoon, H.-I.; Kahveci, Ç.; Abou-Ayash, S.; Yilmaz B.Objectives: To evaluate how restoration thickness (0.5 mm and 0.7 mm) affects the fabrication trueness of additively manufactured definitive resin-based laminate veneers, and to analyze the effect of restoration thickness and margin location on margin quality. Methods: Two maxillary central incisors were prepared either for a 0.5 mm- or 0.7 mm-thick laminate veneer. After acquiring the partial-arch scans of each preparation, laminate veneers were designed and stored as reference data. By using these reference data, a total of 30 resin-based laminate veneers were additively manufactured (n = 15 per thickness). All veneers were digitized and stored as test data. The reference and test data were superimposed to calculate the root mean square values at overall, external, intaglio, and marginal surfaces. The margin quality at labial, incisal, mesial, and distal surfaces was evaluated. Fabrication trueness at each surface was analyzed with independent t-tests, while 2-way analysis of variance was used to analyze the effect of thickness and margin location on margin quality (? = 0.05). Results: Regardless of the evaluated surface, 0.7 mm-thick veneers had lower deviations (P < 0.001). Only the margin location (P < 0.001) affected the margin quality as labial margins had the lowest quality (P < 0.001). Conclusion: Restoration thickness affected the fabrication trueness of resin-based laminate veneers as 0.7 mm-thick veneers had significantly higher trueness. However, restoration thickness did not affect the margin quality and labial margins had the lowest quality. Clinical significance: Laminate veneers fabricated by using tested urethane-based acrylic resin may require less adjustment when fabricated in 0.7 mm thickness. However, marginal integrity issues may be encountered at the labial surface. © 2024Öğe Scan accuracy and time efficiency of different implant-supported fixed partial denture situations depending on the intraoral scanner and scanned area: An in vitro study(Elsevier Inc., 2023) Donmez, M.B.; Mathey, A.; Gäumann, F.; Mathey, A.; Yilmaz, B.; Abou-Ayash, S.Statement of problem: The type of intraoral scanner (IOS), region of the implant, and extent of the scanned area have been reported to affect scan accuracy. However, knowledge of the accuracy of IOSs is scarce when digitizing different partially edentulous situations either with complete- or partial-arch scans. Purpose: The purpose of this in vitro study was to investigate the scan accuracy and time efficiency of complete- and partial-arch scans of different partially edentulous situations with 2 implants and 2 different IOSs. Material and methods: Three maxillary models with implant spaces at the lateral incisor sites (anterior 4-unit), right first premolar and right first molar sites (posterior 3-unit), or right canine and right first molar sites (posterior 4-unit) were fabricated. After placing implants (Straumann S RN) and scan bodies (CARES Mono Scanbody), models were digitized by using an optical scanner (ATOS Capsule 200MV120) to generate reference standard tessellation language (STL) files. Complete- or partial-arch scans (test scans) of each model were then performed by using 2 IOSs (Primescan [PS] and TRIOS 3 [T3]) (n=14). The duration of the scans and the time needed to postprocess the STL file until the design could be started were also recorded. A metrology-grade analysis software program (GOM Inspect 2018) was used to superimpose test scan STLs over the reference STL to calculate 3D distance, interimplant distance, and angular (mesiodistal and buccopalatal) deviations. Nonparametric 2-way analysis of variance followed by Mann-Whitney tests with Holm correction were used for trueness, precision, and time efficiency analyses (?=.05). Results: The interaction between IOSs and scanned area only affected the precision of the scans when angular deviation data were considered (P?.002). Trueness of the scans was affected by IOSs when 3D distance, interimplant distance, and mesiodistal angular deviations were considered. The scanned area affected only 3D distance deviations (P?.006). IOSs and scanned area significantly affected the precision of scans when 3D distance, interimplant distance, and mesiodistal angular deviations were considered, while only IOSs significantly affected buccopalatal angular deviations (P?.040). Scans from PS had higher accuracy when 3D distance deviations were considered for the anterior 4-unit and posterior 3-unit models (P?.030), when interimplant distance deviations were considered for complete-arch scans of the posterior 3-unit model (P?.048), and when mesiodistal angular deviations were considered in the posterior 3-unit model (P?.050). Partial-arch scans had higher accuracy when 3D distance deviations of the posterior 3-unit model were considered (P?.002). PS had higher time efficiency regardless of the model and scanned area (P?.010), while partial-arch scans had higher time efficiency when scanning the posterior 3-unit and posterior 4-unit models with PS and the posterior 3-unit model with T3 (P?.050). Conclusions: Partial-arch scans with PS had similar or better accuracy and time efficiency than other tested scanned area-scanner pairs in tested partial edentulism situations. © 2023 Editorial Council for the Journal of Prosthetic Dentistry
