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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 Effect of internal connection type and screw channel angle on the screw stability of anterior implant-supported zirconia crowns(Wiley, 2023) Cakmak, Guelce; Guven, Mehmet Esad; Donmez, Mustafa Borga; Kahveci, Cigdem; Schimmel, Martin; Abou-Ayash, Samir; Yilmaz, BurakObjectivesTo investigate the effect of implant-abutment connection and screw channel angle on screw stability by comparing a newly introduced and an established connection, before and after cyclic loading.Materials and MethodsImplants (N = 44) with Torcfit (TF) or Crossfit (CF) connection were divided to be restored with a straight (CFS and TFS) or an angled screw access channel (CFA and TFA) titanium-base abutment (n = 11). CFA and TFA received screw-retained crowns, whereas CFS and TFS received hybrid zirconia abutments and cement-retained crowns. The initial torque value (ITV) of each complex (ITVI) and removal torque value (RTV) after 24 h (RTVI) were measured. Screws were replaced with new ones, ITVs were recorded again (ITVF), and crowns were cyclically loaded (2.4 million cycles, 98 N) to measure RTVs again (RTVF). Percentage torque loss was calculated. Data were analyzed (a = 0.05).ResultsITVs were similar among groups (p = .089). CF led to higher RTVs (p = .002), while CFS had higher RTVI than CFA (p = .023). After 24 h, CFS had lower percentage torque loss than TF, while CFA had lower percentage torque loss than TFA (p = .011). After cyclic loading, CF led to lower percentage torque (p < .001).ConclusionThe implant-abutment connection affected the removal torque values. However, no screw loosening occurred during cyclic loading, which indicated a stable connection for all groups. Screw access channel angle did not affect screw stability after cyclic loading.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 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 thermal cycling on the flexural strength and hardness of new-generation denture base materials(WILEY, 2022) Cakmak, Gulce; Donmez, Mustafa Borga; Akay, Canan; Abou-Ayash, Samir; Schimmel, Martin; Yilmaz, BurakPurpose To evaluate the flexural strength and Vickers microhardness of different CAD-CAM denture base materials. Materials and methods Sixty rectangular specimens (64 x 10 x 3.3 +/- 0.2 mm) were fabricated from 3 different denture base materials (G-CAM, Graphene-reinforced polymethylmethacrylate, GC), Ivotion Base (Prepolymerized polymethylmethacrylate, IV), and Denturetec (3D-printed resin, DT) either by using additive (DT) or subtractive manufacturing (IV and GC). Specimens of each group were divided into 2 subgroups (thermal cycled or nonthermal cycled, n = 10/group). Nonthermal cycled specimens were stored in distilled water at 37 degrees C for 24 hours and subjected to 3-point flexural strength test with a universal testing machine. Thermal cycled specimens were initially evaluated for Vickers microhardness and subjected to thermal cycling (10,000 cycles at 5-55 degrees C). Vickers microhardness values were remeasured, and the specimens were subjected to 3-point flexural strength test. Data were analyzed by using 2-way analysis of variance and Bonferroni-corrected Tukey honestly significant difference tests (alpha = 0.05). Results Material type and condition significantly affected flexural strength (p <= 0.004), whereas their interaction was nonsignificant (p = 0.778). Overall flexural strength of the materials in decreasing order was GC, IV, and DT (p < 0.001), regardless of the condition. Material had a higher effect on flexural strength (eta p(2) = 0.731) than thermal cycling (eta p(2) = 0.142). The effect of the interaction between the material type and thermal cycling on Vickers microhardness was significant (p < 0.001). GC had the highest microhardness before and after thermal cycling (p < 0.001). IV had higher microhardness than DT before thermal cycling (p < 0.001). However, DT and IV showed similar microhardness after thermal cycling (p = 0.665). Thermal cycling decreased the microhardness of GC and IV (p <= 0.022), whereas its effect on DT's microhardness was nonsignificant (p = 0.538). Material type had the highest effect on microhardness (eta p(2) = 0.864) followed by the interaction between the main factors (eta p(2) = 0.258). Conclusions Graphene-reinforced polymethylmethacrylate had the highest flexural strength and Vickers microhardness values, regardless of thermal cycling. Thermal cycling reduced the flexural strength of all resins. Thermal cycling reduced the microhardness of milled polymethylmethacrylate, but not that of 3D-printed resin.Öğe Flexural Strength and Vickers Microhardness of Graphene-Doped SnO2 Thin-Film-Coated Polymethylmethacrylate after Thermocycling(Mdpi, 2023) Akay, Canan; Cakmak, Gulce; Donmez, Mustafa Borga; Abou-Ayash, Samir; Mumcu, Emre; Pat, Suat; Yilmaz, BurakRemovable dental prostheses are commonly fabricated using polymethylmethacrylate, a material that does not have favorable mechanical properties and needs reinforcement with particles such as graphene. The aim of this study was to evaluate the flexural strength (FS) and Vickers microhardness of a heat-polymerized polymethylmethacrylate coated with graphene-doped stannic oxide (SnO2) thin films using a thermionic vacuum arc method after thermocycling. Forty bar-shaped specimens (65 x 10 x 3 mm) were fabricated using a heat-polymerized denture base resin and divided into four groups according to the graphene-doped SnO2 thin film surface coating performed: No-coat (uncoated), Coat-15 s (coating duration of 15 s), Coat-20 s (coating duration of 20 s), and Coat-30 s (coating duration of 30 s) (n = 10). The thermionic vacuum arc method was used to coat both surfaces of the specimens of each test group with varying durations, and surface coating was verified using Fourier Transform Infrared Spectroscopy. Specimens were subjected to 10,000 cycles of thermocycling. Atomic force microscopy was used to evaluate the surfaces of all specimens before and after thermocycling. Microhardness values were measured five times and averaged. Then, each specimen was subjected to a three-point bending test, and FS values were calculated. Data were analyzed using one-way analysis of variance and Bonferroni tests (& alpha; = 0.05). Differences among test groups were nonsignificant when FS data were considered (p = 0.605). However, significant differences were observed among test groups when Vickers microhardness data were considered (p < 0.001). Coat-30 s had the highest hardness (p & LE; 0.003), while the difference among remaining groups were nonsignificant (p & GE; 0.166). Graphene-doped SnO2 thin film surface coatings did not significantly affect the FS of tested heat-polymerized denture base resin but increased the Vickers microhardness when the coating duration was 30 s.Öğe In vitro scan accuracy and time efficiency in various implant-supported fixed partial denture situations (vol 127C, 104358, 2022)(Elsevier Sci Ltd, 2023) Abou-Ayash, Samir; Mathey, Amber; Gaumann, Fabio; Mathey, Ayse; Donmez, Mustafa Borga; Yilmaz, Burak[Abstract Not Available]Öğe Surface roughness, optical properties, and microhardness of additively and subtractively manufactured CAD-CAM materials after brushing and coffee thermal cycling(Wiley, 2023) Cakmak, Gulce; Donmez, Mustafa Borga; de Paula, Marcella Silva; Akay, Canan; Fonseca, Manrique; Kahveci, Cigdem; Abou-Ayash, SamirPurpose: To evaluate the surface roughness, optical properties, and microhardness of additively or subtractively manufactured CAD-CAM materials after simulated brushing and coffee thermal cycling.Material and methods: Two additively manufactured resins (Crowntec, CT and VarseoSmile Crown Plus, VS) and 3 subtractively manufactured materials (a reinforced composite (Brilliant Crios, BC), a polymer-infiltrated ceramic network (Enamic, VE), and a feldspathic ceramic (Mark II, VM)) were used to fabricate disk-shaped specimens (& Oslash;10x1-mm) (n = 10). Surface roughness, Vickers microhardness, and color coordinates were measured after polishing, while surface roughness was also measured before polishing. Specimens were then subjected to 25000 cycles of brushing and 10000 cycles of coffee thermal cycling, and measurements were repeated after each time interval. Color difference (Delta E-00) and relative translucency parameter (RTP) were calculated. Robust analysis of variance test was used to evaluate surface roughness, Delta E-00, and RTP data, while generalized linear model analysis was used for microhardness data (alpha = 0.05).Results: Material type and time interval interaction affected tested parameters (p <= 0.002). In addition, material type affected all parameters (p < 0.001) other than surface roughness (p = 0.051), and time interval affected surface roughness and microhardness values (p < 0.001). Tested materials mostly had their highest surface roughness before polishing (p <= 0.026); however, there was no clear trend regarding the roughness of materials within different time intervals along with Delta E00 and RTP values within materials or time intervals. VS and CT had the lowest microhardness regardless of the time interval, while the remaining materials were listed as VM, VE, and BC in decreasing order (p < 0.001). Coffee thermal cycling only reduced the microhardness of VM (p < 0.001).Conclusions: Tested additively manufactured resins can be considered more susceptible to simulated brushing and coffee thermal cycling than the other materials, given the fact that their surface roughness and Delta E00 values were higher than previously reported acceptability thresholds and because they had the lowest microhardness after all procedures were complete.Öğe Trueness and precision of combined healing abutment scan body system scans at different sites of maxilla after multiple repositioning of the scan body(Elsevier Sci Ltd, 2023) Donmez, Mustafa Borga; Guven, Mehmet Esad; Yilmaz, Deniz; Abou-Ayash, Samir; Cakmak, Gulce; Yilmaz, BurakObjectives: To evaluate the accuracy of the scans of the combined healing abutment-scan body (CHA-SB) system located at different sites of the maxilla when SBs are replaced in between each scan.Methods: Three SBs were seated into HAs located at the central incisor, first premolar, and first molar sites of a maxillary model inside a phantom head, and the model was scanned extraorally (CEREC Primescan SW 5.2). This procedure was repeated with new SBs until a total of 10 scans were performed. Standard tessellation language files of CHA-SBs at each implant location were isolated, transferred into analysis software (Geomagic Control X), and superimposed over the proprietary library files to analyze surface (root mean square), linear, and angular deviations. Trueness and precision were evaluated with one-way analysis of variance and Tukey tests. The correlation between surface and angular deviations was analyzed with Pearson's correlation (alpha=0.05).Results: Molar implant scans had the highest surface and angular deviations (P <=.006), while central incisor implant scans had higher precision (surface deviations) than premolar implant scans (P=.041). Premolar implant scans had higher accuracy than central incisor implant scans on the y-axis (P <=.029). Central incisor implant scans had the highest accuracy on the z-axis (P <=.018). A strong positive correlation was observed between surface and angular deviations (r = 0.864, P<.001).Conclusion: Central incisor implant scans mostly had high accuracy and molar implant scans mostly had lower trueness. SBs were mostly positioned apically; however, the effect of SB replacement can be considered small as measured deviations were similar to those in previous studies and the precision of scans was high.Clinical Significance: Repositioning of scan bodies into healing abutments would be expected to result in similar single crown positioning regardless of the location of the implant, considering high scan precision with the healing abutment-scan body system. The duration of the chairside adjustments of crowns in the posterior maxilla may be longer than those in the anterior region.
