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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 thermal cycling on the surface properties and stainability of additively manufactured denture base resins in different layer thicknesses(Wiley, 2023) Cakmak, Guelce; Asadolahi, Nura Watson; Schimmel, Martin; Molinero-Mourelle, Pedro; Akay, Canan; Donmez, Mustafa Borga; Yilmaz, 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 (& Oslash;10x2 mm) were fabricated from two subtractively (Merz M-PM [SM-M] and G-CAM [SM-G]) and three additively (NextDent 3D+ [50 mu m, AM-N-50; 100 mu m, AM-N-100], FREEPRINT Denture [50 mu m, AM-F-50; 100 mu m, AM-F-100], and Denturetec [50 mu m, AM-S-50; 100 mu m, 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 (Delta E00) 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 Delta E00 data (alpha = 0.05). Ra values were further evaluated according to a clinically acceptable threshold of 0.2 mu m, while Delta E00 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 Delta E00 than AM-F, AM-S-100, and SM-G (p <= 0.009), while AM-F and SM-G had lower Delta E00 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.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 final temperature and heating rate on the mechanical and optical properties of a zirconia veneering ceramic(Elsevier, 2024) Coldea, Andrea; Donmez, Mustafa Borga; Stawarczyk, BognaPurpose: To evaluate the effect of firing temperature and heating rate on the volumetric shrinkage, translucency, flexural strength, hardness, and fracture toughness of a zirconia veneering ceramic.Material and methods: Zirconia veneering ceramic specimens (N = 45) with varying final temperatures (730 degrees C, 750 degrees C, and 770 degrees C) and heating rates (70 degrees C/min, 55 degrees C/min, and 40 degrees C/min) were fabricated (n = 5). Each specimen's shrinkage, translucency, flexural strength, hardness, and fracture toughness were determined. Two-way analysis of variance, Scheff & eacute; test, and Pearson's correlation analysis were used to evaluate data (alpha = 0.05).Results: The shrinkage (44.9 +/- 3.1-47.5 +/- 1.6 vol%) and flexural strength (74.1 +/- 17.4-107.0 +/- 27.1 MPa) were not affected by tested parameters (P >= 0.288). The interaction between the main factors affected the translucency, hardness, and fracture toughness of the specimens (P <= 0.007). Specimens with 770 degrees C final temperature and 70 degrees C/min heating rate had the lowest (21.8 +/- 3.2 %) translucency (P <= 0.039). The hardness ranged between 4.98 +/- 0.51 GPa (730 degrees C; 70 degrees C/min) and 5.60 +/- 0.37 GPa (770 degrees C; 70 degrees C/min). Fracture toughness ranged between 0.54 +/- 0.04 MPa root m and 0.67 +/- 0.08 MPa root m with the highest values for specimens fired at 730 degrees C with 70 degrees C/min (P <= 0.001). There was a positive correlation between translucency and hardness (r = 0.335, P = 0.012), and a negative correlation between fracture toughness and all parameters other than shrinkage (translucency: r = -0.693/P < 0.001, flexural strength: r = -0.258/P = 0.046, hardness: r = -0.457/P < 0.001).Conclusions: Heating rate and final temperature should be considered while fabricating veneered zirconia restorations with tested ceramic as they affected the translucency, hardness, and fracture toughness.Öğe 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 material type, torque value, and sterilization on linear displacements of a scan body: An in vitro study(Wiley, 2023) Diker, Emre; Terzioglu, Hakan; Gouveia, Diogo N. M.; Donmez, Mustafa Borga; Seidt, Jeremy; Yilmaz, BurakBackground: There is limited knowledge on the effect of scan body (SB) material type, torque value, and sterilization on linear displacements of implant SBs. Purpose: To evaluate the effect of material type, torque value, and sterilization on linear displacements of SBs during screw tightening by using digital image correlation (DIC) analysis. Materials and Methods: One polyetheretherketone (PEEK, Zfx Intraoral Scan Body) and one titanium SB (Ti, MPS Zimmer Scanbody R1410) were tightened with 5 Ncm torque on two implants (Zimmer TSV circle divide 4.7 mm) by using a digital torque limiting device. SBs' initial spatial positions relative to the implants were recorded by using 3D DIC technique. Measurements were repeated after initially increasing torque value to 10 Ncm and then to 15 Ncm, and these steps were repeated for a total of 10 PEEK and 10 Ti SBs on both implants (n = 20). All SBs were then sterilized 25 times by using an autoclave (STATIM 5000 S G4) according to manufacturer's recommendations and all measurements were repeated. Linear displacements on three axes were calculated for each SB with increasing torque values (from 5 to 10 Ncm and from 10 to 15 Ncm) before and after sterilization. SB displacements within each torque value-sterilization pair were compared by using Mann-Whitney U test, whereas Wilcoxon signed-rank test was used to compare SB displacements within each material-torque value pair between conditions and within each material-sterilization pair between torque values (alpha = 0.05). Results: On x-axis, PEEK SBs had higher displacements than Ti SBs (p < 0.001), whereas sterilization (p <= 0.028) and 15 Ncm torque application (p <= 0.006) led to higher displacements of PEEK SBs. On y-axis, PEEK SBs had higher displacements than Ti SBs with 15 Ncm torque application (p <= 0.033). A total of 15 Ncm torque-applied PEEK SBs and 10 Ncm torque-applied Ti SBs had higher displacements after sterilization (p <= 0.028). Application of 15 Ncm torque led to higher displacements regardless of the material (p <= 0.002). On z-axis, PEEK SBs had higher displacements (p <= 0.015), except for 10 Ncm torque-applied sterilized SBs (p = 0.102). With 10 Ncm torque application, sterilization decreased the displacement values of PEEK SBs (p = 0.044). Greater displacements were observed with 10 Ncm torque-applied Ti SBs before sterilization and 15 Ncm torque-applied PEEK SBs after sterilization (p <= 0.033). Conclusions: Axial displacement of SBs was affected by material type, torque value, and sterilization. Ti SBs mostly had lower displacements than PEEK SBs. Application of 15 Ncm torque to tested PEEK SBs should be refrained from and a calibrated tightening tool may enable the application of 10 Ncm or lower torque values for lower displacements. Sterilization generally increased PEEK SB displacements.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 polishing and denture cleansers on the surface roughness of new-generation denture base materials and their color change after cleansing(Wiley, 2023) Cakmak, Guelce; Hess, Julia Anouk; Donmez, Mustafa Borga; Yilmaz, Deniz; Alhotan, Abdulaziz; Schimmel, Martin; Peutzfeldt, AnnePurpose: To evaluate the effect of polishing and denture cleansers on the surface roughness (Ra) of new-generation denture basematerials that are additively, subtractively, and conventionally fabricated, while also assessing their color change after cleansing. Material and Methods: One hundred and fifty disk-shaped specimens (O10 x 2 mm) were prepared from five denture base materials (one subtractively manufactured nanographene-reinforced prepolymerized polymethylmethacrylate (PMMA) (SM-GC), one subtractively manufactured prepolymerized PMMA (SM-PM), two additively manufactured denture base resins (AM-DT and AM-ND), and one heat-polymerized PMMA (CV) (n = 30). The R-a of the specimens was measured before and after conventional laboratory polishing, while color coordinates were measured after polishing. Specimens were then divided into three subgroups based on the denture cleanser: distilled water, 1% sodium hypochlorite (NaOCl), and effervescent tablet (n = 10). The R-a and color coordinates were remeasured after nine cleansing cycles over a period of 20 days. The CIEDE2000 formula was used to calculate the color differences (Delta E-00). Two-way analysis of variance (ANOVA) was used to analyze the R-a values before (n = 30) and after (n = 10) cleansing, while repeated measures ANOVA was used to analyze the R-a of material-time point pairs within each denture cleanser (n = 10). Delta E-00 data after denture cleansing was also analyzed by using two-way ANOVA (n = 10) (a = 0.05). Results: Before polishing, Ra varied significantly among the materials. SM-GC and SM-PM had the lowest and AM-ND the highest Ra values (P < 0.001). Polishing significantly reduced R-a of all materials (P < 0.001), and after polishing, Ra differences among materials were nonsignificant (P >= 0.072). Regardless of the denture cleanser, the R-a of AM-DT, AM-ND, and CV was the highest before polishing when different time points were considered (P < 0.001). After cleansing, AM-ND had the highest R-a of all the materials, regardless of the cleanser (P <= 0.017). AM-DT had higher R-a than SM-PM when distilled water (P = 0.040) and higher R-a than SM-GC, SM-PM, and CV when NaOCl was used (P < 0.001). The type of cleanser significantly influenced the R-a of AM-DT, AM-ND, and CV. For AM-DT, NaOCl led to the highest R-a and the tablet led to the lowest R-a (P <= 0.042), while for AM-ND, distilled water led to the lowest R-a (P <= 0.024). For CV, the tablet led to lower R-a than distilled water (P = 0.009). Color change varied among the materials. When distilled water was used, SM-GC had higher Delta E-00 than SM-PM and AM-DT (P <= 0.034). When NaOCl was used, AM-ND had higher Delta E-00 than SM-GC, SM-PM, and AM-DT, while CV and SM-GC had higher Delta E-00 than SM-PM and AM-DT (P = 0.039). Finally, when the tablet was used, AM-ND and CV had the highest Delta E-00, while AM-DT had lower Delta E-00 than SM-GC (P = 0.015). Conclusions: The tested materials had unacceptable surface roughness (>0.2 mu m) before polishing. Roughness decreased significantly after polishing (<0.2 mu m). Denture cleansers did not significantly affect the surface roughness of the materials, and roughness remained clinically acceptable after cleansing (<0.2 mu m). Considering previously reported color thresholds, AM-ND and CV had unacceptable color change regardless of the denture cleanser, and the effervescent tablet led to perceptible, but acceptable color change for SM-GC, SM-PM, and AM-DT.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 Effect of Thermomechanical Aging on the Surface Roughness and Color Stability of Novel CAD-CAM Materials: An In-Vitro Study(Marmara Univ, Inst Health Sciences, 2023) Turksayar, Almira Ada Diken; Donmez, Mustafa Borga; Hisarbeyli, Duygu; Kelten, Ozlem SeckinObjective: This in-vitro study aimed to evaluate the surface roughness (Ra) and color stability of novel monolithic CAD-CAM materials after thermomechanical aging. Methods: Forty specimens were obtained from 4 different materials (a resilient ceramic (RC), ceramic-reinforced PEEK (PE), lithium disilicate glass ceramic (EX), and a resin-based composites (CO) (n=10). Initial Ra and color coordinates were recorded. All specimens were than subjected to thermomechanical aging. Ra and color coordinate measurements were repeated. CIEDE2000 formula was used to calculate the color changes (& UDelta;E00). Kruskal-Wallis and Dunn tests were used to analyze data, while the effect of aging on Ra was analyzed with Wilcoxon test (& alpha;=.05). Results: Regardless of aging, PE showed higher Ra than EX (p< .001), whereas the differences between PE and the other materials were nonsignificant (p & GE; .202). Thermomechanical aging led to higher Ra for all materials tested (p= .005). The greatest & UDelta;E00was observed in PE (p & LE; .002), while the difference among the other materials was nonsignificant (p> .05). Ra of ceramic-reinforced PEEK was above clinical threshold, regardless of thermomechanical aging. Conclusion: Thermomechanical aging caused a color change that was perceptible for all the materials tested, while it was also unacceptable for ceramic-reinforced PEEK.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 Fabrication trueness and internal fit of hybrid abutment crowns fabricated by using additively and subtractively manufactured resins(Elsevier Sci Ltd, 2023) Demirel, Muenir; Turksayar, Almira Ada Diken; Donmez, Mustafa BorgaObjectives: To evaluate the fabrication trueness and internal fit of hybrid abutment crowns fabricated by using additively and subtractively manufactured restorative materials.Methods: A maxillary first premolar crown with a screw access channel was designed onto a digitized master titanium base abutment. This file was used to fabricate 40 crowns additively (Crowntec (CT) and VarseoSmile Crown Plus (VS)) or subtractively (Brilliant Crios (BC) and Vita Enamic (EN)) (n = 10). Crowns were digitized with an intraoral scanner and root mean square method was used to evaluate fabrication trueness. Master abutment and the crowns when seated on the abutment were also digitized with the same intraoral scanner and triple scan method was used to evaluate internal fit. Data were analyzed either with 1-way ANOVA (surface deviations) or Kruskal-Wallis (internal fit) tests (& alpha;= 0.05).Results: CT had the highest overall, external, and marginal surface deviations (P<.030), whereas BC had the lowest external (P<.001) and VS and EN had the lowest marginal surface deviations (P<.007). BC had the highest intaglio surface deviations (P<.001). BC and EN had higher average gap values CT and VS (P<.006); however, the differences within additively and subtractively manufactured materials were nonsignificant (P & GE;.858).Conclusions: One of the tested additively manufactured resins (CT) resulted in mostly lower trueness than that of other materials. However, deviations at the intaglio and marginal surfaces were generally small and the maximum mean difference among test groups when average gap was considered was 17.4 & mu;m. Therefore, clinical fit of hybrid abutment crowns fabricated with tested materials may be similar.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 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 Influence of age, training, intraoral scanner, and software version on the scan accuracy of inexperienced operators(Wiley, 2023) Zarauz, Cristina; Pradies, Guillermo Jesus; Chebib, Najla; Donmez, Mustafa Borga; Karasan, Duygu; Sailer, IrenaPurpose: To evaluate the effect of operator age on the scan accuracy (trueness and precision) of inexperienced operators when compared with experienced operators, and how training, intraoral scanner (IOS), and software version affect scan accuracy.Material and Methods: Thirty-four operators were sorted into groups: G1 (operators <25 years old, no experience), G2 (operators >40 years old, no experience), and G3 (experienced IOS operators). They conducted partial-arch scans before and after a 4-session training with two IOSs (Trios 3 and True Definition) and two software versions. These scans were compared with the reference scans obtained from conventional impressions and a laboratory scanner (IScan D103i) to evaluate trueness (mean root mean square values) and precision (standard deviation of root mean square values) with a software program (Geomagic Control X). Kruskal-Wallis and post-hoc Dunn's tests were used to evaluate the effect of age on the scan accuracy of inexperienced groups when compared with experienced operators, while the effect of training, IOS, and software version on scan accuracy was evaluated with Wilcoxon or Mann-Whitney U tests (alpha = 0.05).Results: Before training, G1 and G2 scans had similar accuracy (p >= 0.065). After training, G1 scans had higher accuracy when IOS data was pooled and had higher precision with TD (p <= 0.004). Training increased the scan accuracy (p < 0.001), while newer software increased the trueness of inexperienced operator scans (p = 0.015).Conclusions: Age affected the scan accuracy of inexperienced operators after training, indicating that extended training may be required for older operators. Training increased the scan accuracy, and newer software increased the trueness of inexperienced operator scans.Öğe Influence of implant scan body design (height, diameter, geometry, material, and retention system) on intraoral scanning accuracy: A systematic review(Wiley, 2023) Gomez-Polo, Miguel; Donmez, Mustafa Borga; Cakmak, Guelce; Yilmaz, Burak; Revilla-Leon, MartaPurposeTo evaluate the influence of implant scan body (ISB) design (height, diameter, geometry, material, and retention system) on the accuracy of digital implant scans.Material and MethodsA literature search was completed in five databases: PubMed/Medline, Scopus, Embase, World of Science, and Cochrane. A manual search was also conducted. Studies reporting the evaluation of ISB design on the accuracy of digital scans obtained by using IOSs were included. Two investigators evaluated the studies independently by applying the Joanna Briggs Institute critical appraisal. A third examiner was consulted to resolve any lack of consensus. Articles were classified based on the ISB features of height, geometry, material, and retention system.ResultsTwenty articles were included. Among the reviewed studies, 11 investigations analyzed the influence of different ISB geometries, 1 study assessed the impact of ISB diameter, 4 studies investigated the effect of ISB splinting, 2 articles evaluated ISB height, and 2 studies focused on the effect of ISB material on scan accuracy. In addition, 8 studies involved ISBs fabricated with different materials (1- and 2-piece polyetheretherketone and 1-piece titanium ISBs), and all of the reviewed articles tested screw-retained ISBs, except for 3 in vitro studies.ConclusionsThe findings did not enable concrete conclusions regarding the optimal ISB design, whether there is a relationship between IOS technology and a specific ISB design, or the clinical condition that maximizes intraoral scanning accuracy. Research efforts are needed to identify the optimal ISB design and its possible relationship with the IOS selected for acquiring intraoral digital implant scans.
