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Öğe Comparison of intraoral and laboratory scanners to an industrial-grade scanner while analyzing the fabrication trueness of polymer and titanium complete-arch implant-supported frameworks(Elsevier Sci Ltd, 2023) Yilmaz, Burak; Dede, Dogu Omur; Donmez, Mustafa Borga; Kucukekenci, Ahmet Serkan; Lu, Wei-En; Schumacher, Fernanda Lang; Cakmak, GulceObjectives: To compare the scans of different intraoral scanners (IOSs) and laboratory scanners (LBSs) to those of an industrial-grade optical scanner by measuring deviations of complete-arch implant-supported frameworks from their virtual design file. Material and methods: Ten polyetheretherketone (PEEK) and 10 titanium (Ti) complete-arch implant-supported frameworks were milled from a master standard tessellation language (STL) file. An industrial-grade blue light scanner (AT), 2 LBSs (MT and E4), and 3 IOSs (PS, T3, and T4) were used to generate STL files of these frameworks. All STLs were imported into an analysis software (Geomagic Control X) and overall root mean square (RMS) values were calculated. Marginal surfaces of all STL files were then virtually isolated (Medit Link v 2.4.4) and marginal RMS values were calculated. Deviations in scans of tested scanners were compared with those in scans of AT by using a linear mixed effects model (alpha = 0.05). Results: When the scans of PEEK frameworks were considered, PS and T3 had similar overall RMS to those of AT (p >= .076). However, E4 and T4 had higher and MT had lower overall RMS than AT (p <= .002) with a maximum estimated mean difference of 13.41 mu m. When the scans of Ti frameworks were considered, AT had significantly lower overall RMS than tested scanners (p <= .010) with a maximum estimated mean difference of 31.35 mu m. Scans of tested scanners led to significantly higher marginal RMS than scans of AT (p <= .006) with a maximum estimated mean difference of 53.90 mu m for PEEK and 40.50 mu m for Ti frameworks. Conclusion: Only the PEEK framework scans of PS and T3 led to similar overall deviations to those of AT. However, scans of all tested scanners resulted in higher marginal deviations than those of AT scans. Clinical Significance: Scans performed by using PS and T3 may be alternatives to those of tested reference industrial scanner AT, for the overall fabrication trueness analysis of complete-arch implant-supported PEEK frameworks.Öğe Effect of coffee thermocycling on the surface roughness and stainability of denture base materials with different chemical compositions manufactured with additive and subtractive technologies(Wiley, 2024) Cakmak, Gulce; Weber, Franziska Alexandra; Donmez, Mustafa Borga; Kahveci, Cigdem; Schimmel, Martin; Yilmaz, BurakObjectiveTo evaluate the effect of coffee thermocycling (CTC) on the surface roughness (Ra) and stainability of denture base materials with different chemical compositions fabricated by using additive and subtractive manufacturing.Materials and MethodsDisk-shaped specimens were additively (FREEPRINT denture, AM) or subtractively (G-CAM, GSM and M-PM, SM) fabricated from three pink denture base materials in different chemical compositions (n = 10). Ra was measured before and after polishing, while color coordinates were measured after polishing. Specimens were subjected to CTC (5000 cycles) and measurements were repeated. Color differences (& UDelta;E00) after CTC were calculated. Ra among different time intervals within materials was evaluated by using repeated measures analysis of variance (ANOVA), while 1-way ANOVA was used to evaluate the Ra of different materials within each time interval and the & UDelta;E00 values. Color coordinates within each material were compared by using paired samples t-tests (a = 0.05).ResultsRa before polishing was the highest for all materials (p < 0.001), while SM had its lowest Ra after CTC and AM had its lowest Ra after polishing (p & LE; 0.008). Before polishing, AM had the highest Ra among the materials (p < 0.001). After polishing, SM had higher Ra than AM (p < 0.001). After CTC, GSM had the lowest Ra (p & LE; 0.048). SM had the lowest (p & LE; 0.031) and AM had the highest (p < 0.001) & UDelta;E00. CTC decreased the a* and b* values of SM and AM (p & LE; 0.017), and increased the L* values of AM (p < 0.001).ConclusionsPolishing significantly reduced the surface roughness of all materials. CTC did not increase the surface roughness of materials above the clinically acceptable threshold. Only AM had perceptible color change when previously reported threshold values for denture base materials were considered.Clinical SignificanceTested denture base materials may have similar surface stability after coffee thermocycling. However, subtractively manufactured denture base materials may have improved color stability when subjected to long-term coffee consumption.Öğe Effect of coffee thermocycling on the surface roughness and stainability of nanographene-reinforced polymethyl methacrylate used for fixed definitive prostheses(Mosby-Elsevier, 2023) Cakmak, Gulce; Herren, Kira Vera; Donmez, Mustafa Borga; Kahveci, Cigern; Schimmel, Martin; Yilmaz, BurakStatement of problem. A nanographene-reinforced polymethyl methacrylate (PMMA) has been introduced for definitive prostheses. However, knowledge on the surface roughness and stainability of this material is lacking.Purpose. The purpose of this in vitro study was to compare the surface roughness and stainability of nanographene-reinforced PMMA with those of a prepolymerized PMMA and a reinforced composite resin after coffee thermocycling.Material and methods. Disk-shaped specimens (F10x1.5-mm) were prepared from 3 different A1-shade millable resins (prepolymerized PMMA [M-PM; PMMA]; nanographene-reinforced PMMA [G-CAM; G-PMMA]; reinforced composite resin [Brilliant Crios; RCR]). Surface roughness (R-a) values were measured before and after conventional polishing by using a noncontact profilometer. Initial color coordinates were measured over a gray background with a spectrophotometer after polishing. Specimens were then thermocycled in coffee for 5000 cycles. Measurements were repeated after coffee thermocycling, and color differences (?E-00) were calculated. R-a values among different time intervals were analyzed by using either the Friedman and Dunn tests (RCR) or repeated measures analysis of variance (ANOVA) and Bonferroni corrected paired samples t tests (PMMA and G-PMMA), while R-a values within a time interval were analyzed by using either the Kruskal-Wallis and Dunn tests (before polishing) or 1-way ANOVA and Tukey HSD (after polishing) or Tamhane T2 tests (after coffee thermocycling). ?E-00 values were analyzed by using 1-way ANOVA and Tukey HSD tests, while color coordinates of the specimens after polishing and after coffee thermocycling were compared by using paired samples t tests (a=.05).Results. All materials had their highest R-a values before polishing (P=.011), while differences after polishing and after coffee thermocycling values were nonsignificant (P=.140). PMMA had higher R(a )than RCR before polishing (P=.002), and RCR had higher values than G-PMMA after polishing and after coffee thermocycling (P=.023). RCR had the highest ?E-00 (P=.001). Polishing increased the b* values of PMMA, and coffee thermocycling increased the a* values of G-PMMA and all values of RCR (P=.012).Conclusions. The tested materials had similar and acceptable surface roughness after polishing. The surface roughness of materials was not affected by coffee thermocycling. Considering the reported color thresholds, all materials had acceptable color change, but the computer-aided design and computer-aided manufacturing composite resin had perceptible color change after coffee thermocycling.Öğe Effect of computer-aided design and computer-aided manufacturing technique on the accuracy of fixed partial denture patterns used for casting or pressing(Elsevier Sci Ltd, 2023) Donmez, Mustafa Borga; Yilmaz, Burak; Yoon, Hyung-In; Kahveci, Cigdem; Schimmel, Martin; Cakmak, GulceObjectives: To evaluate the effect of additive and subtractive manufacturing on the accuracy (trueness and pre-cision) of fixed partial denture patterns (FPDPs) used for casting or pressing.Materials and Methods: A 3-unit complete coverage FPD on mandibular right first premolar and first molar teeth was virtually designed. Using the design data, FPD patterns were fabricated from an additively manufactured resin (PR, ProArt Print Wax) and 2 CAD-CAM wax discs (YW, ProArt CAD Wax Yellow and BW, ProArt CAD Wax Blue) (n = 10). Each pattern was then digitized with a scanner (CEREC Primescan) and evaluated for 3D surface deviation at 4 different surfaces (overall, external, marginal, and intaglio surfaces) by using a 3D analysis software (Medit Link). Root mean square (RMS) values were automatically calculated. Data were analyzed by using Kruskal-Wallis and Dunn's post hoc tests for trueness and precision (alpha= 0.05).Results: Significant differences were found among the RMS values for overall (P<.001) and each surface (P <=.040) evaluated. PR had the highest overall (P <=.011) and intaglio surface (P <=.01) deviations, while the difference between YW and BW was not significant (P >=.199). PR had the highest (P <=.027) and BW had the lowest (P <=.042) external surface mean RMS values. BW had higher mean marginal RMS value than YW (P=.047). For precision, significant differences were observed among test groups only for marginal RMS values (P=.002). PR had lower precision than BW (P=.002).Conclusions: BW and YW FPDPs mostly had higher trueness compared with PR FPDPs. However, considering relatively smaller deviations at marginal and intaglio surfaces and the fact that patterns mostly had similar precision, clinical fit of FPDs fabricated by using tested patterns may be similar.Clinical Significance: Definitive 3-unit fixed partial dentures fabricated by using tested patterns may be similar. However, FPDs fabricated with tested additively manufactured resin patterns might result in more chairside adjustments than those fabricated with tested subtractively manufactured wax patterns.Öğe Effect of number of supports and build angle on the fabrication and internal fit accuracy of additively manufactured definitive resin-ceramic hybrid crowns(Elsevier Sci Ltd, 2023) Cakmak, Gulce; Agovic, Dino; Donmez, Mustafa Borga; Kahveci, Cigdem; de Paula, Marcella Silva; Schimmel, Martin; Yilmaz, BurakObjectives: To evaluate the effect of number of supports and build angle on the fabrication and internal fit ac-curacy (trueness and precision) of additively manufactured resin-ceramic hybrid crowns. Methods: A mandibular first molar crown was designed and nested on the build platform of a printer either with a 30 degrees angle between the occlusal surface and the build platform (BLS (less support) and BMS (more support)) or its occlusal surface parallel to the build platform (VLS (less support) and VMS (more support)) to fabricate addi-tively manufactured resin-ceramic hybrid crowns (n = 14). After fabrication, supports were removed by a blinded operator and all crowns were digitized with an intraoral scanner. Fabrication accuracy (overall, external, intaglio occlusal, occlusal, and marginal) was evaluated by using root mean square (RMS) method, while internal fit was evaluated with triple scan method. RMS, average gap, and precision of these data were analyzed (alpha= 0.05).esults: VLS had higher overall deviations than BLS and VMS (P <=.039). VMS had higher occlusal deviations than BLS (P=.033). While BMS and BLS had higher marginal deviations than VLS (P <=.006), BMS also had higher values than VMS (P=.012). BLS led to higher precision than VMS (intaglio occlusal and occlusal surfaces) and VLS (occlusal surface) (P <=.008). VLS led to higher precision than BMS (marginal surface) (P=.027). Average gap values were similar (P=.723); however, BLS resulted in higher precision than VLS (P=.018).Conclusions: Considering their high marginal and occlusal surface trueness, and similar internal occlusal de-viations and average gaps (trueness), clinical fit of resin-ceramic hybrid crowns fabricated with tested parameters may be similar. Reduced number of supports and angled orientation may lead to higher precision of fit. Clinical Significance: Tested resin-ceramic hybrid-printer pair may be used to fabricate crowns with reduced number of supports to maintain occlusal surface integrity without compromising the fabrication accuracy and fit.Öğe Effect of scan powder and scanning technology on measured deviations of complete-arch implant supported frameworks digitized with industrial and intraoral scanners(Elsevier Sci Ltd, 2023) Donmez, Mustafa Borga; Cakmak, Gulce; Dede, Dogu Omur; Kucukekenci, Ahmet Serkan; Lu, Wei-En; Schumacher, Fernanda Lang; Revilla-Leon, MartaObjectives: To evaluate the suitability of intraoral scanners (IOSs) to analyze the fabrication trueness of titanium complete-arch implant-supported frameworks by comparing with an industrial-grade scanner and investigate how anti-reflective scan powder affects measured deviations.Methods: Ten titanium complete-arch implant-supported frameworks were milled from a reference standard tessellation language (STL) file. An industrial-grade blue light scanner (ATOS Core 80 (AT)) and three IOSs (Primescan (PS), TRIOS T3 (T3), and TRIOS T4 (T4)) with (PS-P, T3-P, and T4-P) or without (PS, T3, and T4) anti-reflective scan powder application were used to generate test STL (TSTL) files of the frameworks. Reference STL and TSTLs were imported into a metrology-grade analysis software (Geomagic Control X) and whole surface root mean square (RMS) values were calculated. Another software (Medit Link v 2.4.4) was used to virtually isolate marginal surfaces of all STL files and marginal RMS values were calculated by using the same metrologygrade analysis software. A linear mixed effects model was used to compare the transformed deviations of the scans performed by using each IOS (with or without powder) with the deviations of those performed by using the reference AT scanner within each surface, where a Box-Cox type transformation was used for variance stability. Bonferroni corrected post-hoc tests were used to compare conditions within each IOS (alpha=0.05).Results: All IOSs had significantly higher whole surface and marginal RMS values than AT, regardless of the condition (P <=.002). However, scan powder application did not affect the whole surface and marginal RMS values in scans of tested IOSs (P >=.054).Conclusion: Measured whole surface and marginal deviations in all IOS scans performed with or without the use of scan powder were higher than those in AT scans. The application of anti-reflective scan powder did not affect the deviations in scans of tested IOSs.Clinical Significance: Even though deviations measured in the scans of tested scanners were significantly different than those in the reference scanner, the maximum raw mean difference was 37.33 mu m and the maximum raw confidence interval value of estimated differences was 47.88 mu m, which can be considered clinically small taking into account the size of the frameworks tested. Therefore, tested intraoral scanners may be feasible to scan prostheses similar to or smaller than tested frameworks for fabrication trueness analysis, which may facilitate potential clinical adjustments.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 Evaluation of Dimensional Stability and Occlusal Wear of Additively and Subtractively Manufactured Resin-Based Crowns after Thermomechanical Aging(Mdpi, 2023) Guven, Mehmet Esad; Cakmak, Gulce; Donmez, Mustafa Borga; Yilmaz, BurakThe knowledge on the surface deviations and wear of recently introduced additively or subtractively manufactured materials indicated for definitive prosthesis is limited. The aim of this present study was to evaluate the external surface and mesiodistal width deviation and the occlusal surface wear of one additively manufactured composite resin (MS) and three subtractively manufactured resins (nanographene-reinforced polymethylmethacrylate (GR), conventional polymethylmethacrylate (PMMA), and reinforced composite resin (BC)) after thermomechanical aging. Molar-shaped crowns were fabricated in the tested materials and digitized with an intraoral scanner (CEREC Primescan; Dentsply Sirona, Bensheim, Germany). Each crown was subjected to thermomechanical aging and rescanned with the same scanner. A three-dimensional analysis software (Geomagic Control X v.2022.1; 3D Systems, Rock Hill, SC, USA) was used to calculate the deviations on the external surface, mesiodistal width, and wear on the occlusal surfaces of the tested crowns. Data were analyzed using one-way ANOVA and Tukey's tests (alpha = 0.05). MS had higher external surface deviations than PMMA and GR (p <= 0.038) and higher mesiodistal width deviations than PMMA and BC (p = 0.004). BC and GR had higher volume loss than PMMA (p <= 0.002). The additively manufactured composite resin was more prone to deviations, while reinforced composite resin had lower wear resistance than most of the tested materials.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 Implementation of triple-scan protocol to evaluate the fit of complete-arch implant-supported fixed prostheses(Wiley, 2024) Donmez, Mustafa Borga; Cakmak, Gulce; Schimmel, Martin; Yilmaz, BurakPassive fit is essential for multiple-unit implant-supported prostheses. Conventional methods to assess the passivity of complete-arch implant-supported prostheses do not allow 3-dimensional (3D) visualization and quantification of misfit. This report describes the marginal and internal fit evaluation of a complete-arch implant-supported prosthesis by using the triple-scan protocol involving a scanner and a 3D analysis freeware. This technique allows researchers, clinicians, or dental technicians to detect and quantify 3D prosthetic misfit, which may facilitate the preparation for dental appointments and objective measurement of misfit for research studies.Öğe Influence of polishing technique and coffee thermal cycling on the surface roughness and color stability of additively and subtractively manufactured resins used for definitive restorations(Wiley, 2023) Cakmak, Gulce; Oosterveen-Ruegsegger, Alice Lisa; Akay, Canan; Schimmel, Martin; Yilmaz, Burak; Donmez, Mustafa BorgaPurposeTo evaluate how different polishing techniques and coffee thermal cycling affect the surface roughness and stainability of additively and subtractively manufactured resins used for definitive prostheses. Materials and MethodsTwo additively manufactured composite resins (Crowntec, CT and VarseoSmile Crown Plus, VS) and a subtractively manufactured resin nanoceramic (Cerasmart, CS) were used to fabricate 90 rectangular-shaped specimens (14 x 12 x 1 mm) (n = 30). After baseline surface roughness (R-a) measurements, specimens were divided into three groups based on the polishing technique; conventional polishing with a 2-stage polishing kit (CP) and surface sealant application (Optiglaze, OG or Vita Akzent LC, VA) (n = 10). After polishing, specimens were subjected to 10,000 cycles of coffee thermal cycling. R-a and color coordinate measurements were performed after polishing and after coffee thermal cycling. Color difference (& UDelta;E-00) was calculated. Scanning electron microscope images were taken at each time interval. Kruskal-Wallis or 1-way analysis of variance (ANOVA) were used to evaluate R-a of materials within each polishing-time interval pair and different polishing techniques within each material-time interval pair, while Friedman or repeated measures ANOVA were used to evaluate R-a at different time intervals within each material-polishing pair. & UDelta;E-00 was assessed with 2-way ANOVA (& alpha; = 0.05). ResultsOther than VA-after polishing (p = 0.055), tested materials had significantly different R-a within each polishing-time interval pair (p & LE; 0.038). When R-a differences among different polishing techniques within each material-time interval pair were considered, CS had differences after coffee thermal cycling, CT had differences before polishing and after coffee thermal cycling, and VS had differences within each time interval (p & LE; 0.038). When R-a differences among different time intervals within each material-polishing pair were considered, significant differences were observed among all pairs (p & LE; 0.016), except for CS-VA (p = 0.695) and VS-VA (p = 0.300). & UDelta;E-00 values were affected by material and polishing technique interaction (p = 0.007). ConclusionsR(a) of CS was similar to or lower than the R-a of other materials, regardless of the time interval or polishing technique. CP mostly led to lower R-a than other polishing techniques, whereas VA resulted in a high R-a regardless of the material-time interval pair. Polishing reduced the R-a, while coffee thermal cycling was found to have a small effect. Among tested material-polishing pairs, only CS-VA had moderately unacceptable color change when previously reported threshold values were considered.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.
