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Öğe Additive or subtractive manufacturing of crown patterns used for pressing or casting: A trueness analysis(Elsevier Science, 2022) Çakmak, Gülce; Dönmez, Mustafa Borga; Cuellar, Alfonso Rodrigues; Kahveci, Çiğdem; Schimmel, Martin; Yılmaz, BurakObjectives: To investigate the effect of subtractive and additive manufacturing techniques on the trueness of crown patterns used for pressing or casting. Material and Methods: A complete-coverage mandibular right first molar crown was designed in standard tessellation language (STL) format. This STL served as the control (C- STL) and was used to fabricate 30 crown patterns in 3D-printed resin (PR, ProArt Print Wax), millable wax suitable for casting (BW, ProArt CAD Wax Blue), and millable wax suitable for pressing (YW, ProArt CAD Wax Yellow) (n=10). Subtractively manufactured patterns were fabricated by using a 5-axis milling unit (PrograMill PM7), while 3D-printed patterns were fabricated by using a digital light processing-based 3D printer (PrograPrint PR5; Ivoclar Vivadent, Schaan, Liechtenstein). All fabricated patterns were digitized by using an intraoral scanner (CEREC Primescan SW 5.2) to generate test-STLs. C-STL and test-STLs were transferred into a 3D analysis software (Medit Link v 2.4.4). Trueness evaluation was performed at 4 different surfaces (external, intaglio with margin, marginal, and intaglio without margin) and for complete scan meshes (overall) by using the root mean square (RMS) method. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests (?=.05). Results: RMS values varied significantly at all surfaces (P<.001), except for marginal surface (P=.151). PR had the highest RMS values at external surface (P?.007), intaglio surfaces (with (P?.003) and without margin (P?.005)), and overall (P?.01). No significant differences were observed between YW and BW (P?.223). Conclusion: Patterns fabricated by using subtractive manufacturing exhibited high trueness. The deviation values, in general, were small, particularly at intaglio and marginal surfaces; thus, clinical difference in crown-fit may be negligible using additive or subtractive technique. Clinical Significance The fit of definitive crowns may be similar when tested crown patterns are additively or subtractively manufactured. However, crowns fabricated by using tested 3D-printed resin patterns may require more chairside adjustments compared with those fabricated by using subtractively manufactured wax patterns.Öğe Cameo and intaglio surface stability and variability of additively, subtractively, and conventionally manufactured occlusal devices after long-term storage(Elsevier, 2024) Orgev, Ahmet; Dönmez, Mustafa Borga; Almogbel, Lolowh; Çakmak, Gülce; Marques, Vinicius Rizzo; Kahveci, Çiğdem; Yılmaz, BurakStatement of problem: Additive and subtractive manufacturing have become alternative technologies for fabricating occlusal devices. However, knowledge of the long-term stability of occlusal devices fabricated using these recent technologies is limited. Purpose: The purpose of this in vitro study was to evaluate the cameo and intaglio surface stability and variability of additively, subtractively, and conventionally manufactured occlusal devices after 18 months of storage. Material and methods: A standard tessellation language (STL) file of a dentate maxillary typodont was used to design a master occlusal device. The STL file of this design was used to fabricate occlusal devices additively either with a digital light processing (AM-1) or a continuous liquid interface production (AM-2) printer, subtractively with 2 different 5-axis milling units (SM-1 and SM-2), and conventionally (TM-HP) (n=10). STL files of each device's cameo and intaglio surfaces were generated using a laboratory scanner after fabrication and after 18 months of storage in a moist environment. These generated files were imported into an analysis software program (Geomagic Control X) to analyze the dimensional stability of tested devices by using the root mean square method. The average deviation values defined the variability of measured changes over time. Cameo and intaglio surface deviations were analyzed using the Kruskal-Wallis and Dunn tests, while the variability of measured deviations was analyzed with 1-way analysis of variance and the Tukey HSD tests (α=.05). Results: Significant differences were observed among tested devices when the intaglio surface deviations and the cameo surface variability were considered (P<.001). SM-2 had significantly higher intaglio surface deviations than AM-1, SM-1, and AM-2 (P≤.036). Among the test groups, AM-1 had the greatest cameo surface variability (P≤.004). Conclusions: SM-2 resulted in lower intaglio surface stability than the additive and the other subtractive manufacturing technologies, while AM-1 led to the highest cameo surface variability among the test groups.Öğe Color and translucency of milled polymethyl methacrylate crowns on non-tooth-colored interim abutments with different surface treatments(2022) Çakmak, Gülce; Cuellar, Alfonso Rodriguez; Treviño Santos, Alejandro; Johnston, William M; Dönmez, Mustafa Borga; Yılmaz, BurakStatement of problem: The interim rehabilitation of implants has become a necessity, particularly for those placed in the esthetic regions. However, the optical properties of computer-aided design and computer-aided manufacturing (CAD-CAM) polymethyl methacrylate (PMMA) crowns on interim abutments with different surface treatments are unclear. Purpose: The purpose of this in vitro study was to investigate the color and translucency of CAD-CAM PMMA crowns when different surface treatments were used on titanium interim abutments. Material and methods: A maxillary dentate stone cast with a narrow-diameter implant analog at the left lateral incisor site was used. Three titanium interim abutments (blue) were divided into 3 groups according to the surface treatment they received: control (steam cleaning), opaqued (120-?m Al2O3 airborne-particle abrasion and opaque application), and airborne-particle abraded (120-?m Al2O3). Thirty PMMA crowns (A2 shade) were milled (n=10). The color coordinates of the crown-interim abutment pairs and a shade tab (A2) were measured by using a colorimeter. The color differences (?E00) between the crowns and the shade tab and the relative translucency parameter (RTP) values of the crowns were calculated by using the CIEDE2000 formula. One-way ANOVA was used to analyze the ?E00 and RTP values with subsequent Tukey honestly significant difference tests (?=.05). Results: The abutment surface treatment significantly affected the ?E00 of interim crowns from the shade tab (P<.001), but no significant effect was found on RTP (P=.26). The control group had the highest ?E00 from the shade tab (P?.011). No significant difference (P=.14) was found between the opaqued and the ?E00 of the airborne-particle abraded groups from the shade tab. Conclusions: The surface treatments of interim abutments affected the color of CAD-CAM PMMA crowns, which differed from that of the shade tab. The color of crowns on opaqued or airborne-particle abraded interim abutments was closer to the color of the shade tab. Abutment surface treatments did not affect the translucency of crown-interim abutment pairs.Öğe Comparison of measured deviations in digital implant scans depending on software and operator(Elsevier, 2022) Çakmak, Gülce; Marques, Vinicius Rizzo; Dönmez, Mustafa Borga; Lu, Wei-En; Abou-Ayash, Samir; Yılmaz, BurakObjectives: To investigate the effect of 3-dimensional (3D) analysis software and operator on the measured deviations in implant scans. Material and Methods: A combined healing abutment-scan body (CHA-SB) system was digitized with an industrial scanner (ATOS Core 80) to generate a master standard tessellation language file (MRM-STL) and an intraoral scanner (TRIOS 3) to generate 9 test-scan STL files, which were transferred into metrology-grade (Geomagic Control X, GX and GOM Inspect, GM) and nonmetrology-grade (Medit Link, ML) software for deviation analysis. Test-scan STLs were superimposed over MRM-STL and 2 planes passing through the center of the SB were generated. Distance deviations at 8 points on these planes were analyzed by two different operators with similar level of experience. Data were analyzed with analysis of variance and F tests (?=.05). Results: Only model 1 (P=.049) analyzed by operator 2 showed significant differences among tested software, and the highest deviations were measured with GM (P?.037). However, the difference in values measured with GX and ML was nonsignificant (P=.91). Operator correlation was high (ICC?.712, P?.011), except for models 1 (GM, ICC=-.335, P=.813), 2 (GM, ICC=.025, P=.468 and ML, ICC=-.013, P=.507), 6 (GM, ICC=-.085, P=.583), and 8 (GM, ICC=-.386, P=.85). Conclusion: The measured deviations in implant scans in all models, except for one, were similar among the tested software, regardless of the operator. The inter-rater reliability of operators while using tested 3D analysis software was overall high. When observed, low inter-rater reliability was mostly with only one of the metrology grade software. Clinical Significance: Nonmetrology-grade 3D analysis software may be a suitable alternative to metrology-grade software to measure the deviations in digital implant scan body scans. When GOM metrology-software is used, measured deviations in implant scan body scans may vary more across operators. © 2022Öğe Dimensional Stability of Additively Manufactured Diagnostic Maxillary Casts Fabricated with Different Model Resins(Quintessence Publishing Co. Inc., 2024) Dönmez, Mustafa Borga; Wepfer, Alena Bruna; Güven, Mehmet Esad; Çakmak, Gülce; Schimmel, Martin; Yılmaz, BurakPurpose: To evaluate the effect of model resin type and time interval on the dimensional stability of additively manufactured diagnostic casts. Materials and Methods: Ten irreversible hydrocolloid impressions and 10 impressions from an intraoral scanner were made from a reference maxillary stone cast, which was also digitized with a laboratory scanner. Conventional impressions were poured in type III stone (SC), while digital impressions were used to additively manufacture casts with a nanographene-reinforced model resin (GP) or a model resin (DM). All casts were digitized with the same laboratory scanner 1 day (T0), 1 week (T1), 2 weeks (T2), 3 weeks (T3), and 4 weeks (T4) after fabrication. Cast scans were superimposed over the reference cast scan to evaluate dimensional stability. Data were analyzed with Bonferroni-corrected repeated measures ANOVA (α =.05). Results: The interaction between the main factors (material type and time interval) affected anterior teeth deviations, while the individual main factors affected anterior teeth and entire-cast deviations (P ≤.008). Within anterior teeth, DM had the lowest deviations at T3, and GP mostly had lower values at T2 and lower deviations at T3 than at T0 (P ≤.041). SC had the highest pooled anterior teeth deviations, and GP had the highest pooled entire cast deviations (P <.001). T3 had lower pooled anterior teeth deviations than at T0, T1, and T4, and higher pooled entire cast deviations than T1 were demonstrated (P ≤.027). Conclusions: The trueness of nanographene-reinforced casts was either similar to or higher than that of other casts. Dimensional changes were acceptable during the course of 1 month. © 2024 by Quintessence Publishing Co Inc.Öğe Effect of coffee thermal cycling on the surface properties and stainability of additively manufactured denture base resins in different layer thicknesses(John Wiley and Sons Inc, 2025) Çakmak, Gülce; Asadolahi, Nura Watson; Schimmel, Martin; Molinero-Mourelle, Pedro; Akay, Canan; Dönmez, Mustafa Borga; Yılmaz, BurakPurpose: To compare the effect of coffee thermal cycling on surface roughness (Ra), Vickers microhardness (MH), and stainability of denture base resins additively manufactured in different layer thicknesses with those of subtractively manufactured denture base materials. Materials and Methods: Eighty disk-shaped specimens (Ø10×2 mm) were fabricated from two subtractively (Merz M-PM [SM-M] and G-CAM [SM-G]) and three additively (NextDent 3D+ [50 µm, AM-N-50; 100 µm, AM-N-100], FREEPRINT Denture [50 µm, AM-F-50; 100 µm, AM-F-100], and Denturetec [50 µm, AM-S-50; 100 µm, AM-S-100]) manufactured denture base materials (n = 10). Ra measurements were performed before and after polishing by using a non-contact optical profilometer, while MH values and color coordinates were measured after polishing. Specimens were then subjected to 5000 cycles of coffee thermal cycling, all measurements were repeated, and color differences (ΔE00) were calculated. A linear mixed effect model was used to analyze Ra and MH data, while one-way analysis of variance was used to analyze ΔE00 data (α = 0.05). Ra values were further evaluated according to a clinically acceptable threshold of 0.2 µm, while ΔE00 values were evaluated according to perceptibility (1.72 units) and acceptability (4.08 units) thresholds. The interaction between the material type and the time interval affected both Ra and MH (p ≤ 0.001). Tested materials had their highest Ra before polishing (p ≤ 0.029). Before polishing, AM-F-100 had the highest, and SM-M and SM-G had the lowest Ra (p < 0.001). After polishing and after coffee thermal cycling, SM-G mostly had lower Ra than those of other materials (p ≤ 0.036). SM-G mostly had higher MH than that of other materials before and after coffee thermal cycling (p ≤ 0.025). Coffee thermal cycling reduced the MH of SM-M and increased that of AM-S-100 (p ≤ 0.024). AM-N-100 had higher ΔE00 than AM-F, AM-S-100, and SM-G (p ≤ 0.009), while AM-F and SM-G had lower ΔE00 than AM-S-50 and AM-N-50 (p ≤ 0.024). Conclusions: Polishing reduced the surface roughness of all materials, whereas the effect of coffee thermal cycling was nonsignificant. Most of the tested materials had acceptable surface roughness after polishing and after coffee thermal cycling according to the reported threshold. Layer thickness only affected the microhardness of tested additively manufactured resins, which was material-dependent. Subtractively manufactured specimens mostly had high microhardness and that of nonreinforced subtractively manufactured resin decreased after coffee thermal cycling. When reported color thresholds are considered, all materials had acceptable color stability. © 2023 The Authors. Journal of Prosthodontics published by Wiley Periodicals LLC on behalf of American College of Prosthodontists.Öğe Effect of different surface treatments and thermomechanical aging on the ion elution of CAD-CAM materials(Elsevier Science, 2022) Sert, Murat; Gülce Subaşı, Meryem; Çakmak, Gülce; Dönmez, Mustafa Borga; Yılmaz, BurakStatement of problem. Dental ceramics have been reported to elute ions when subjected to nonneutral pH. However, the effect of surface treatments and thermomechanical aging on the ion elution of CAD-CAM ceramics is unclear. Purpose. The purpose of this in vitro study was to compare the effect of surface treatment (glazed or polished) and thermomechanical aging on the ion elution of CAD-CAM materials before and after 2-body wear simulation. Material and methods. Specimens were prepared from 6 CAD-CAM materialsdleucite (LC), feldspathic (FP), zirconia-reinforced lithium silicate (ZLS), lithium disilicate (LDS) glass-ceramics, polymer-infiltrated ceramic network (PICN), and zirconia (ZIR)dand divided into 2 groups according to the surface treatments (glazed or polished) (n=6). For baseline ion elution values, specimens were placed into polyethylene bottles containing deionized water (pH 7.4) that had been stored in an incubator for 168 hours at 37 C. The eluted ions in the immersion solution were measured by using inductively coupled plasma-optic emission spectrophotometry. The specimens were then subjected to thermomechanical aging by using human enamel as an antagonist. After aging, the ion elution of the specimens was remeasured. Ion elution data before and after 2-body wear were analyzed by using the Mann-Whitney U test, while the effect of 2-body wear was assessed by using the Wilcoxon signed rank test (a=.05). Results. The presence of some ions varied depending on the material-surface treatment pair before (Al, As, B, Ba, Ca, K, Li, Mg, Na, P, and Zn) and after (Al, B, Ba, Ca, Co, Li, Mg, and P) 2-body wear. Polished materials had higher ion elution than the glazed materials before 2-body wear (P .041), except for LC (P and Zn) and PICN (Ca, Cu, and K) (P .009). After 2-body wear, polished LC (B and Ba), FP (Al, B, and Mg), ZLS (Al, Ba, Ca, and Li), ZIR (B and Ba), glazed PICN (Ca, Mg, and P), ZLS (P), and ZIR (Co) presented higher ion elution than their counterparts (P .041). The effect of 2-body wear on the ion elution of polished LC (Al, K), FP (Na), ZLS (Li), LDS (K, Na), PICN (Al, Na), ZIR (Na, Y), glazed LC (Na), FP (Ba, Na), ZLS (B, Ba, Y), LDS (Na), PICN (Y), and ZIR (Na) was nonsignificant (P .075). However, the elution of remaining ions showed a significant difference before and after 2-body wear (P .046). Conclusions. The chemical stability of tested CAD-CAM materials was affected by the 2-body wear. Glazing led to a lower ion elution except for LDS and PICN. While polishing resulted in lower ion elution for PICN, both surface treatments resulted in similar ion elution for LDS. (J Prosthet Dent 2022;-:---)Öğe Effect of firing cycle and aging on long-term chemical degradation of monolithic CAD-CAM ceramics(Elsevier Science, 2022) Sert, Murat; Gülce Subaşı, Meryem; Dönmez, Mustafa Borga; Çakmak, Gülce; Yiımaz, BurakStatement of problem. Previous studies have shown the susceptibility of dental ceramics to degradation when subjected to certain media. However, knowledge on the effect of repeated firings and thermocycling on the ion elution of computer-aided design and computer-aided manufacturing (CAD-CAM) ceramics is lacking. Purpose. The purpose of this in vitro study was to compare the effect of repeated firings on the ion elution of CAD-CAM materials before and after thermocycling. Material and methods. Bar-shaped specimens were prepared from 4 different CAD-CAM materials (monolithic zirconia [Z], zirconia- reinforced lithium silicate glass-ceramic [S], lithium disilicate glass-ceramic [EX], and leucite-reinforced glass-ceramic [E]) and divided into 3 groups according to the number of repeated glaze firings (1 firing [1F], 2 firings [2F], and 4 firings [4F]). Specimens were placed into deionized water (pH 7.4) and stored at 37 C for 168 hours. Inductively coupled plasma-optic emission spectrophotometry (ICP-OES) was used to measure the baseline values of the eluted ions in immersion. The specimens were then subjected to thermocycling. Then, surface roughness (Ra) and ion elution values were measured. The Kruskal-Wallis and Mann-Whitney U tests were used to analyze the ion elution data before and after thermocycling, and the effect of thermocycling on ion elution was assessed by the Wilcoxon signed rank test. Ra data were analyzed with 2-way analysis of variance (ANOVA) and the Tukey honestly significant difference tests (a=.05). Results. Elution of some ions varied depending on the material-firing pair before (Al, As, B, Ba, Cr, Cu, Li, Mg, Na, P, and Zn) and after (Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, K, Li, Mg, Na, P, Y, and Zn) thermocycling. Before thermocycling, all firing groups within each material showed a similar number of significantly higher eluted ions. After thermocycling, the number of significantly higher eluted ions decreased in all materials, except for EX. The effect of thermocycling on the ion elution of the 1F group of Z (Al, Be, Ca, Cd, Co, Cr, Cu, K, Li, P, Y, and Zn), S (As, Be, Cd, Co, Cr, K, P, and Y), EX (B, Cu, and P), and E (B and Ba); 2F group of Z (Al, Be, Ca, Co, Cr, Cu, K, Li, P, and Y), S (Be, Cd, Co, K, Li, and Y), EX (P), and E (P); 4F group of Z (Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, K, Li, P, and Y), S (Al, Be, Cd, Co, Cr, Li, Mg, and Y), EX (Be, Ca, Cd, Co, K, Y, and Zn), and E (Ca and P) was nonsignificant (P .051). The interaction between material and repeated firings (P<.001) had a significant effect on Ra. For 1F groups, E showed the highest Ra (P .003), while Z had higher Ra than S (P=.009). For 2F groups, Z had higher Ra than S (P=.01). The differences among 4F groups were nonsignificant (P .677). An increased number of repeated firings (2F and 4F) decreased the Ra of E (P<.001). Conclusions. The effect of repeated firings and thermocycling on the chemical stability of the tested CAD-CAM materials varied. No clear trend was observed on the elution of different ions within material-firing pairs before thermocycling. However, thermocycling increased the number of significantly higher eluted ions for EX. The effect of thermocycling on the ion elution of materials varied depending on ions. Repeated firings decreased the surface roughness of E. (J Prosthet Dent 2022;-:---)Öğe Effect of measurement techniques and operators on measured deviations in digital implant scans(ELSEVIER, 2022) Çakmak, Gülce; Dönmez, Mustafa Borga; Akay, Canan; De Silva, Marcella Paula; Mangano, F. G.; Abou-Ayash, S.; Yılmaz, BurakObjectives: To evaluate the effect of different measurement techniques and operators on measured deviations in in vitro implant scans. Methods: A 2-piece system that comprises a healing abutment (HA) and a scan body (SB) was mounted onto an implant at right first molar site of a polymethylmethacrylate mandibular dentate model. Model was digitized by using an industrial scanner (reference model scan, n=1) and an intraoral scanner (test scan, n=20). All standard tessellation language files were imported into a 3-dimensional analysis software and superimposed. Three operators with similar experience performed circle-based and point-based deviation analyses (n=20). Deviations measured with different techniques were compared with paired samples t-test within each operator, while the reliability of the operators was assessed by using F-tests for both technqiues (?=.05). Results: Point-based technique resulted in lower deviations than circle-based technique for all operators (P=.001) with to higher reliability among operators (ICC=.438, P=.001). The correlation among the operators was nonsignificant when circle-based technique was used (ICC=.114, P=.189). Conclusion: Lower deviations were detected with the point-based technique. In addition, different operators' measurements had higher correlation when point-based technique was used compared with circle-based technique. Clinical significance: Point-based technique may be preferred over circle-based technique for research studies on scan accuracy of implants, given its higher reliability. The accuracy of measured deviations may increase if the number of planes are increased, which can facilitate point generation at different surfaces of the scan body.Öğe Effect of Polymerization Unit, Polishing, and Coffee Thermocycling on the Color and Translucency of Additively Manufactured Resins Used for Definitive Prostheses(Quintessence Publishing Co. Inc., 2024) Dönmez, Mustafa Borga; Çakmak, Gülce; Sabatini, Gabriela Panca; Kahveci, Çiğdem; Orğev, Ahmet; Yoon, Hyunğ-In; Yılmaz, BurakPurpose: To evaluate the effect of polymerization unit, polishing, and coffee thermocycling on the color and translucency of additively manufactured polyurethane-based resins with different viscosities. In addition, their color behavior was compared with the color of the shade tab throughout the fabrication steps and aging. Materials and Methods: Disk-shaped specimens (010 X 2 mm) were fabricated from polyurethane-based resins with different viscosities (Tera Harz TC-80DP and C&B permanent; n = 30 per material). Baseline color coordinates were measured after cleaning. The specimens in each resin group were divided into three subgroups (n = 10 per subgroup) to be polymerized with different polymerization units (Otoflash G171 [FLN], Wash and Cure 2.0 [CLED1], and P Cure [CLED2]), polished, and subjected to coffee thermocycling. Color coordinates were remeasured after each process. Color differences (ΔE00) and relative translucency parameter (RTP) values were calculated. Data were statistically analyzed (α =. 05). Results: Time points and polymerization units affected the ΔE00 for each material (P<. 049). ΔE00 of each polymerization unit pair had significant differences within and among different time points within each material (P <. 024). ΔE00 (when compared with the shade tab) and RTP were mostly affected by polymerization units and time points within both materials (P <. 042). Conclusions: Tested polymerization units, polishing, and coffee thermocycling affected the color difference and translucency of tested resins. Color differences ranged from moderately unacceptable to extremely unacceptable, and the differences in translucency values mostly ranged from perceptible to unacceptable, according to previous thresholds. In addition, tested resin-polymerization unit pairs had unacceptable color differences when compared to the shade tab. CLED1 may enable higher color stability for tested resins © (2024), (Quintessence Publishing Co. Inc.). All Rights Reserved.Öğe Effect of potassium aluminum sulfate application on the viability of fibroblasts on a cad-cam feldspathic ceramic before and after thermocycling(PMID, 2022) Çakmak, Gülce; Akay, Canan; Dönmez, Mustafa Borga; Mumcu, Emre; Akan, Handan Sevim; Sasany, Rafat; Abou-Ayash, Samir; Yılmaz, BurakAbstract: Potassium aluminum sulfate (alum) is a known adjuvant, which has been used as a mordant in textile industry for color fixation. This material has potential to be incorporated into dentistry for color stability, yet its toxicity first needs to be evaluated. The present study aimed to evaluate the cytotoxic potential of potassium aluminum sulfate (alum) on fibroblasts when applied onto feldspathic ceramic before and after thermocycling. Forty-eight feldspathic ceramic specimens were divided into four groups (FC: no alum application or thermocycling; FCT: thermocycling without alum application; FA: alum application without thermocycling; FAT: alum application and thermocycling) (n = 12). Cell viability was assessed by using a tetrazolium salt 3-[4,5-dimethylthiazol2-yl]-2,5-diphnyltetrazolium bromide assay at 24 and 72 h, and cell cultures without any ceramic specimens served as control (C). One sample from each material group was further analyzed with energy dispersive X-ray spectroscopy (EDX). Cell viability at different time intervals within each group was analyzed with Friedman tests, while Kruskal–Wallis tests were used to compare the test groups within each time interval. Pairwise comparisons were further resolved by using Wilcoxon tests (a = 0.05). C had lower (p = 0.01) and FA had higher (p = 0.019) cell viability after 72 h. After 24 h, the highest cell viability was observed in C (p ? 0.036). After 72 h, the differences between C and FA, C and FAT, FC and FA, and FCT and FAT were nonsignificant (p > 0.05). Cell viability was not affected by alum application or thermocycling at any time interval (p ? 0.631). EDX analysis showed an increase in potassium concentration in FA and FAT when compared with FC and FCT. Regardless of the time interval, alum application onto feldspathic ceramic and thermocycling did not influence the cell viability.Öğe Effect of printing layer thickness on the trueness and fit of additively manufactured removable dies(Elsevier, 2022) Yılmaz, Burak; Dönmez, Mustafa Borga; Kahveci, Çiğdem; Cuellar, Alfonso Rodrigues; de Paula, Marcella Silva; Schimmel, Martin; Abou-Ayash, Samirl; Çakmak, GülceStatement of problem: Additive manufacturing is commonly used for the fabrication of definitive casts with removable dies. However, how the trueness and fit of removable dies are affected by printing layer thickness is lacking. Purpose: The purpose of this in vitro study was to investigate the trueness and fit of additively manufactured removable dies printed in different layer thicknesses. Material and methods: A mandibular cast with a prepared right first molar tooth was digitized (CEREC Primescan), and its standard tessellation language (STL) file was imported into a software program (DentalCAD 3.0). A removable die (D-STL) and a hollow cast with (M-STL) or without the die (SM-STL) were designed. D-STL and SM-STL were imported into a nesting software program (Composer), and 45 removable dies in 3 layer thicknesses (100 ?m, 50 ?m, and 50 to 100 ?m) (n=15) and 1 cast (100-?m) were additively manufactured. Each removable die (TD-STLs), the cast with each die (TM-STLs), and the cast without the die (TSM-STL) were digitized by using the same scanner. All STL files were imported into a software program (Medit Link v 2.4.4), and TD-STLs were superimposed over D-STL. The root mean square (RMS) method was used to analyze the trueness of the dies at 2 different areas (crown and root portion) and as a complete unit (overall). Overall RMS values of the cast with and without the die were also calculated after superimposing TM-STLs over M-STL. The fit of the dies in the cast was evaluated by using a triple-scan protocol to measure deviations at 5 different points (point M: most mesial point of the margin; point TM: tip of the mesial cusp; point O: deepest point of the occlusal fossa; point TD: tip of the distal cusp; point D: most distal point of the margin) on the crown portion. One-way ANOVA and Tukey honestly significant difference tests were used to evaluate data (?=.05). Results: The RMS values of removable dies showed significant differences at each area (P?.002). The 50- to 100-?m group had higher overall RMS values than the 100-?m group (P=.017). The 100-?m group had the highest RMS values for the crown portion (P?.019), while the 50-?m group had the highest RMS values for the root portion (P<.001). The 50-?m group had the lowest RMS values for the crown portion when the die was in the cast (P<.001). Except for point TM (P=.228), significant differences were observed among the test groups at all points (P<.001). The 50-?m group had the lowest distance deviations at points M, TD, and D (P?.005), while the 100-?m group had the highest distance deviations at points O and D (P?.010). Conclusions: Removable dies fabricated by using a 100-?m or 50- to 100-?m combined layer thickness had trueness that was either similar to or better than that of dies fabricated with a 50-?m layer thickness. When the die was on the cast, the 50-?m layer thickness resulted in the best crown portion trueness. However, because the deviation differences among groups were clinically small, the 100-?m layer thickness can be considered for the efficient fabrication of removable dies when the tested printer and resin are used. © 2022 Editorial Council for the Journal of Prosthetic DentistryÖğe Effect of printing layer thickness on the trueness of 3-unit interim fixed partial dentures(Elsevier Science, 2022) Çakmak, Gülce; Cuellar, Alfonso Rodriguez; Dönmez, Mustafa Borga; Abou-Ayash, Samir; Lu, Wei-En; Schimmel, Martin; Yılmaz, BurakStatement of problem. Three-dimensional printing has facilitated the fabrication processes in dentistry. However, knowledge on the effect of layer thickness on the trueness of 3D-printed fixed partial dentures (FPDs) is lacking. Purpose. The purpose of this in vitro study was to compare the effect of printing layer thickness on the trueness of 3-unit interim FPDs fabricated by using additive manufacturing with that of those fabricated by subtractive manufacturing. Material and methods. The right first premolar and first molar teeth of a dentate mandibular model were prepared for a 3-unit restoration and then digitized by using an intraoral scanner. A 3-unit interim FPD was designed to fabricate 40 restorations by using either the additive (NextDent C&B MFH) with layer thicknesses of 20 mm (n=10), 50 mm (n=10), and 100 mm (n=10) or subtractive manufacturing technique (Upcera) (milled, n=10). After fabrication, the interim FPDs were digitized by using the same intraoral scanner and were superimposed over the design data by using a 3D analysis software program. Root mean square (RMS) was used to analyze the trueness of the restorations at 4 different surfaces (external, intaglio, marginal area, and intaglio occlusal) and as a complete unit (overall). Data were analyzed with the Kruskal-Wallis and Wilcoxon tests with Bonferroni correction (a=.05). Results. The 100-mm-layer thickness interim FPDs showed the greatest overall (P .015), external (P .021), and intaglio occlusal (P .021) deviations, whereas the milled interim FPDs showed the lowest (P=.001). No significant differences were found among the test groups for marginal RMS (P .108). The differences between the 50-mm-layer thickness and 100-mm-layer thickness interim FPDs for the intaglio surface deviations (P=.064) and between the 20-mm-layer thickness and 50- mm-layer thickness interim FPDs for each surface tested were not statistically significant (P .108). Conclusions. The printing layer thickness had a significant effect on the trueness of the additively manufactured interim FPDs. However, subtractively manufactured interim FPDs presented higher trueness than those additively manufactured, regardless of the printing layer thickness. (J Pros- thet Dent 2022;-:---)Öğe Effect of scanned area and operator on the accuracy of dentate arch scans with a single implant(MDPI, 2022) Marques, Vinicius Rizzo; Çakmak, Gülce; Yılmaz, Hakan; Abou-Ayash, Samir; Dönmez, Mustafa Borga; Yılmaz, BurakStudies have shown the effect of the operator and scanned areas on the accuracy of single implant scans. However, the knowledge on the scan accuracy of the remaining dental arch during single implant scans, which may affect the occlusion, is limited. The aim of this study was to investigate the effect of scanned areas and the operator on the scan accuracy of a dentate arch while scanning a single implant. A dentate model with an anterior implant was digitized with a laboratory scanner (reference scan). Three operators with similar experience performed 10 complete- and 10 partial-arch scans (left 2nd molar to right canine) with an intraoral scanner (TRIOS 3), and these scans were superimposed over the reference. The accuracy was analyzed at 22 points in complete-arch and at 16 points in partial-arch scans on 2nd molars and incisors. Data were evaluated with 2-way ANOVA and Tukey HSD tests (? = 0.05). The trueness of the total scanned area was higher in partialthan in complete-arch scans (p < 0.001). The trueness and precision of the scans were higher in the anterior site compared with the posterior in complete- (trueness: p ? 0.022, precision: p ? 0.003) and partial-arch (trueness: p ? 0.016, precision: p ? 0.016) scans of each operator and when the operator scan data were pooled. The complete-arch scan’s precision was not influenced by the operator (p ? 0.029), whereas the partial-arch scans of operator 1 and 2 were significantly different (p = 0.036). Trueness was higher in partial- compared with complete-arch scans, but their precision was similar. Accuracy was higher in the anterior site regardless of the scan being a partial- or a complete-arch. The operator’s effect on the accuracy of partial- and complete-arch scans was small.Öğe Effect of simulated brushing and disinfection on the surface roughness and color stability of CAD-CAM denture base materials(Elsevier Science, 2022) Çakmak, Gülce; Dönmez, Mustafa Borga; Akay, Canan; Atalay, Sevda; Silva de Paula, Marcella; Schimmel, Martin; Yılmaz, BurakPurpose: To evaluate the effect of simulated brushing and chemical disinfection on the surface roughness and color stability of CAD-CAM denture base materials and to compare with those of a heat-cured denture base material. Material and methods: Disk-shaped specimens (Ø 10mm × 2 mm) were prepared from 3 CAD-CAM denture base resins (AvaDent, Ava; Merz M-PM, Merz; Polident d.o.o, Poli) and a heat-cured polymethylmethacrylate resin (Promolux, Conv) (n = 30). After polishing, baseline surface roughness (Ra) and color coordinates were measured. The measurements were repeated after 20000 cycles of simulated brushing, and the specimens were divided into 3 groups according to disinfection protocol (distilled water, 1% sodium hypochlorite (NaOCl), and effervescent tablet) (n = 10). After 9 cleaning cycles over a period of 20 days, Ra and color coordinates were remeasured. Color differences (?E00) were calculated by using CIEDE2000 formula. One-way analysis of vari- ance (ANOVA) and pairwise t-tests were used to analyze Ra and ?E00 data, while repeated measures ANOVA test was used to compare baseline, after brush, and after disinfection Ra values (? = 0.05). Results: Brushing did not affect the Ra values of tested materials (P ? .08). Both before and after brushing, Merz and Conv had higher Ra values than Poli and Ava (P < .001). Among disinfectants, effervescent tablet led to the lowest Ra for Merz (P = .003) and the highest Ra for Poli (P ? .039). Only NaOCl resulted in significant dif- ferences among the Ra of materials (P < .001), as Merz and Conv had higher Ra values than Poli (P ? .002). Repeated measures ANOVA revealed that effervescent tablet disinfection of Merz led to lower Ra values than those of baseline and after brushing (P ? .042). After brushing, Ava and Conv had higher ?E00 values compared with Merz and Poli (P ? .015). When compared with other disinfection protocols, effervescent tablet led to higher ?E00 values for Merz and Poli (P < .001). Significant differences were observed among materials when NaOCl was used; Conv had higher ?E00 values than Ava and Merz (P = .004). Conclusions: Brushing did not increase the surface roughness of materials. Disinfection protocol’s effect on the surface roughness varied. The effect of brushing on the color of materials varied; color of Ava and Conv was affected from brushing more than the other materials. Color stability of materials varied depending on the disinfection protocol. Effervescent tablet caused higher color change with Merz and Poli compared with other disinfectants. NaOCl led to small color change for Poli, Ava, and Merz materials.Öğe Fatigue behavior of implant-supported cantilevered prostheses in recently introduced CAD-CAM polymers: An in vitro study(Elsevier Inc., 2024) Dönmez, Mustafa Borga; Çakmak, Gülce; Güven, Mehmet Esad; Dede, Doğu Ömür; Abou Ayash, Samir; Yılmaz, BurakStatement of problem: Cantilevered complete arch implant-supported prostheses are commonly fabricated from zirconia and more recently from strength gradient zirconia. Different polymer-based materials indicated for definitive fixed prostheses that could be used with additive or subtractive manufacturing have also been marketed recently. However, knowledge on the long-term fatigue behavior of cantilevered implant-supported prostheses made from these polymer-based materials and strength gradient zirconia is lacking. Purpose: The purpose of this in vitro study was to evaluate the fatigue behavior of implant-supported cantilevered prostheses of recently introduced computer-aided design and computer-aided manufacturing polymers and zirconia. Material and methods: A master standard tessellation language file of a 9×11×20-mm specimen with a titanium base (Ti-base) space that represented an implant-supported cantilevered prosthesis was used to fabricate specimens from additively manufactured interim resin (AM), polymethyl methacrylate (SM-PM), nanographene-reinforced polymethyl methacrylate (SM-GR), high-impact polymer composite resin (SM-CR), and strength gradient zirconia (SM-ZR) (n=10). Each specimen was prepared by following the respective manufacturer's recommendations, and Ti-base abutments were cemented with an autopolymerizing luting composite resin. After cementation, the specimens were mounted in a mastication simulator and subjected to 1.2 million loading cycles under 100 N at 1.5 Hz; surviving specimens were subjected to another 1.2 million loading cycles under 200 N at 1.5 Hz. The load was applied to the cantilever extension, 12-mm from the clamp of the mastication simulator. The Kaplan–Meier survival analysis and Cox proportional hazards model were used to evaluate the data (α=.05). Results: Significant differences in survival rate and hazard ratio were observed among materials (P<.001). Among tested materials, SM-ZR had the highest and AM had the lowest survival rate (P≤.031). All materials had a significantly higher hazard ratio than SM-ZR (P≤.011) in the increasing order of SM-GR, SM-PM, SM-CR, and AM. Conclusions: SM-ZR had the highest survival rate with no failed specimens. Even though most of the tested polymer-based materials failed during cyclic loading, these failures were commonly observed during the second 1.2 million loading cycles with 200 N. All materials had a higher hazard ratio than SM-ZR. © 2024 The AuthorsÖğe Fracture resistance of additively or subtractively manufactured resin-based definitive crowns: Effect of restorative material, resin cement, and cyclic loading(Elsevier, 2024) Çakmak, Gülce; Dönmez, Mustafa Borga; Molinero-Mourelle, Pedro; Kahveci, Çiğdem; Abou-Ayash, Samir; Peutzfeldt, Anne; Yılmaz, BurakObjective: To evaluate how restorative material, resin cement, and cyclic loading affect the fracture resistance of resin -based crowns fabricated by using additive or subtractive manufacturing. Methods: A right first molar crown standard tessellation language (STL) file was used to fabricate 120 crowns from one subtractively manufactured polymerinfiltrated ceramic network (SM) and two additively manufactured resin composites (AM -B and AM -S) (N = 40). These crowns were randomly divided into 4 groups within each material according to the dual -polymerizing resin cement to be used (RX and PN) and the aging condition (n = 10). After cementation, the crowns without cyclic loading were subjected to fracture testing, while the others were first cyclically loaded (1.7 Hz, 1.2 million cycles, and 49-N load) and then subjected to fracture testing. Data were analyzed with generalized linear model analysis ( alpha = .05). Results: Fracture resistance of the crowns was affected by material, resin cement, and cyclic loading ( P <= .030). However, none of the interactions significantly affected fracture resistance of tested crowns ( P >= .140). Among tested materials, SM had the highest fracture resistance, whereas AM -B had the lowest ( P <= .025). RX led to higher fracture resistance, and cyclic loading decreased the fracture resistance ( P <= .026). Significance: Tested materials can be considered reliable in terms of fracture resistance in short- or mid-term (5 years of intraoral simulation) when used for single molar crowns with 2 mm occlusal thickness. In the long term, polymer -infiltrated ceramic network crowns cemented with RelyX Universal may provide promising results and be less prone to complications considering higher fracture resistance values obtained.Öğe Fracture resistance of additively or subtractively manufactured resin-based definitive crowns: Effect of restorative material, resin cement, and cyclic loading(Elsevier Inc., 2024) Çakmak, Gülce; Dönmez, Mustafa Borga; Molinero-Mourelle, Pedro; Kahveci, Çiğdem; Abou Ayash, Samir; Peutzfeldt, Anne; Yılmaz, BurakObjective: To evaluate how restorative material, resin cement, and cyclic loading affect the fracture resistance of resin-based crowns fabricated by using additive or subtractive manufacturing. Methods: A right first molar crown standard tessellation language (STL) file was used to fabricate 120 crowns from one subtractively manufactured polymer-infiltrated ceramic network (SM) and two additively manufactured resin composites (AM-B and AM-S) (N = 40). These crowns were randomly divided into 4 groups within each material according to the dual-polymerizing resin cement to be used (RX and PN) and the aging condition (n = 10). After cementation, the crowns without cyclic loading were subjected to fracture testing, while the others were first cyclically loaded (1.7 Hz, 1.2 million cycles, and 49-N load) and then subjected to fracture testing. Data were analyzed with generalized linear model analysis (α = .05). Results: Fracture resistance of the crowns was affected by material, resin cement, and cyclic loading (P ≤ .030). However, none of the interactions significantly affected fracture resistance of tested crowns (P ≥ .140). Among tested materials, SM had the highest fracture resistance, whereas AM-B had the lowest (P ≤ .025). RX led to higher fracture resistance, and cyclic loading decreased the fracture resistance (P ≤ .026). Significance: Tested materials can be considered reliable in terms of fracture resistance in short- or mid-term (5 years of intraoral simulation) when used for single molar crowns with 2 mm occlusal thickness. In the long term, polymer-infiltrated ceramic network crowns cemented with RelyX Universal may provide promising results and be less prone to complications considering higher fracture resistance values obtained. © 2024 The AuthorsÖğe Surface roughness and color stability of 3D-Printed denture base materials after simulated brushing and thermocycling(MDPI, 2022) Çakmak, Gülce; Molinero Mourelle, Pedro; De Paula, Marcella Silva; Akay, Canan; Cuellar, Alfonso Rodriguez; Dönmez, Mustafa Borga; Yılmaz, BurakThree-dimensional (3D) printing is increasingly used to fabricate denture base materials. However, information on the effect of simulated brushing and thermocycling on the surface roughness and color stability of 3D-printed denture base materials is lacking. The aim of this study was to evaluate the effect of brushing and thermocycling on the surface roughness and color stability of 3D-printed denture base materials and to compare with those of milled and heat-polymerized denture base resins. Disk-shaped specimens (Ø 10 mm × 2 mm) were prepared from 4 different denture base resins (NextDent Denture 3D+ (ND); Denturetec (SC); Polident d.o.o (PD); Promolux (CNV)) (n = 10). Surface roughness (Ra) values were measured before and after polishing with a profilometer. Initial color coordinates were measured by using a spectrophotometer after polishing. Specimens were then consecutively subjected to simulated brushing (10,000 cycles), thermocycling (10,000 cycles), and brushing (10,000 cycles) again. Ra and color coordinates were measured after each interval. Color differences (?E00) between each interval were calculated and these values were further evaluated considering previously reported perceptibility (1.72 units) and acceptability (4.08 units) thresholds. Data were analyzed with Friedman, Kruskal–Wallis, and Mann–Whitney U tests (? = 0.05). Ra (p ? 0.051) and ?E00 (p ? 0.061) values among different time intervals within each material were similar. Within each time interval, significant differences in Ra (p ? 0.002) and ?E00 values (p ? 0.001) were observed among materials. Polishing, brushing, and thermocycling resulted in acceptable surface roughness for all materials that were either similar to or below 0.2 µm. Color of ND printed resin was affected by brushing and thermocycling. All materials had acceptable color stability when reported thresholds are considered.Öğe Surface roughness and stainability of CAD-CAM denture base materials after simulated brushing and coffee thermocycling(Elsevier, 2022) Çakmak, Gülce; Dönmez, Mustafa Borga; Atalay, Sevda; Silva de Paula, Marcella; Fonseca, Manruque; Schimmel, Martin; Yılmaz, BurakStatement of problem: Denture bases machined from prepolymerized materials have become popular. However, information on the effect of simulated brushing and coffee thermocycling (CTC) on their surface roughness and stainability is lacking. Purpose: The purpose of this in vitro study was to compare the effect of simulated brushing and CTC on the surface roughness (Ra) and stainability of computer-aided design and computer-aided manufacturing (CAD-CAM) denture base materials and a heat-polymerized denture base material. Material and methods: Forty disk-shaped specimens were prepared from 3 CAD-CAM denture base resins (AvaDent, AV; Merz M-PM, M-PM; and Polident d.o.o, Poli) and a heat-polymerized polymethylmethacrylate resin (Promolux, CV) (n=10). Ra values of the specimens were measured by using a noncontact profilometer after conventional polishing. The color coordinates were also measured over a gray background with a spectrophotometer. Specimens were then consecutively subjected to simulated brushing for 20 000 cycles, CTC for 5000 cycles, and another 10 000 brushing cycles. Ra and color coordinates were measured after each interval. Color differences (?E00) were calculated by using the CIEDE2000 formula, and the data were analyzed by using 2-way analysis of variance and Tukey honestly significant difference tests (?=0.05). Results: The time interval had a significant effect on Ra (P<.001) as brushing cycles resulted in higher values than those at baseline and after CTC (P<.001). However, the differences between brushing cycles (P=.143) and between the baseline and after CTC (P=.994) were not significant. The interaction between the material type and time interval was significant for ?E00 (P=.016). The only significant difference in ?E00 values was observed between M-PM and CV after all treatments were completed (P=.029). Conclusions: Brushing increased the Ra of all materials when compared with the baseline. All materials showed similar stainability throughout the brushing and CTC processes. However, M-PM CAD-CAM denture base resin underwent a greater color change after all treatments were completed than conventional denture base resin. All color changes can be considered clinically small, considering reported perceptibility and acceptability thresholds.
