Klinik Bilimler Bölümü Makale Koleksiyonu

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https://hdl.handle.net/20.500.12713/1796

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Negotiating the second mesiobuccal canal: a comparison of nickel titanium files through the experience of undergraduate dental students
(WILEY, 2023) Atav Ateş, Ayfer; Arıcan, Burçin; Çiftçioglu, Elif; Küçükay, Enver Sedat
ObjectivesThe aim of this study was to compare the ability of undergraduate students to reach working length (WL) in second mesiobuccal root canals (MB2) of maxillary first molars (n = 210) by using Reciproc Blue without glide path preparation, and One Curve with glide path preparation. MethodsThe students (n = 105) attended theoretical and practical courses. The first group (n = 53) shaped MB2 root canals using the One Curve system and then Reciproc Blue; the second group (n = 52) shaped MB2 root canals following the reverse sequence. Participants completed a questionnaire. The chi-square and Mann-Whitney U test were used for statistical analysis using significance of p The full WL was reached and shaping procedures were completed without complications in Reciproc Blue and One Curve groups at rates of 86.67% and 82.85%, respectively (p > 0.05). Treatment time was shorter in Reciproc Blue (p < 0.05). More (62.9%) students felt the One Curve system safer, while 61% felt the Reciproc Blue system faster. ConclusionsWithin the limitations of this study, instrument kinematics and glide path preparation did not interfere with undergraduate students' ability to achieve the WL in MB2 root canals.
Optical properties, biaxial flexural strength, and reliability of new-generation lithium disilicate glass-ceramics after thermal cycling
(WILEY, 2023) Türksayar, Almira Ada Diken; Demirel, Münir; Dönmez, Mustafa Borga
PurposeTo investigate the color stability, translucency, biaxial flexural strength (BFS), and reliability of nano-lithium disilicate and fully crystallized lithium disilicate after thermal cycling and to compare with those of a commonly used lithium disilicate. Materials and methodsThree lithium disilicate glass-ceramics were used to prepare disk-shaped specimens (o:12 mm, thickness: 1.2 mm) from A2 shaded HT blocks (Amber Mill, AM; Initial LiSi Block, IN; IPS e.max CAD, EX). AM and EX specimens were crystallized, and all specimens were polished with a polishing paste (Diamond Polish Mint). A spectrophotometer (CM-26d) was used to measure color coordinates before and after thermal cycling. BFS test was performed after thermal cycling. Color differences (Delta E-00) and relative translucency parameter (RTP) values were calculated. One-way analysis of variance (ANOVA) (Delta E-00 and BFS), two-way ANOVA followed by Tukey's HSD tests (RTP), and chi-square tests (Weibull modulus and characteristic strength) were used for the statistical analyses (alpha = 0.05). ResultsNo significant differences were observed among the Delta E-00 values of tested materials (df = 2, F = 2.933, p = 0.070). RTP values were only affected by material type (p < 0.001) as AM had the highest RTP (p < 0.001), whereas IN and EX had similar values (p >= 0.165). BFS values varied among tested materials (df = 2, F = 21.341, p < 0.001). AM and EX had similar BFS values (p = 0.067) that were higher than that of IN (p <= 0.001). Weibull moduli of the materials were similar (p = 0.305), whereas EX had the highest and IN had the lowest characteristic strength values (p < 0.001) ConclusionsAlthough nano-lithium disilicate had the highest translucency, all materials had imperceptible color and translucency changes after thermal cycling when reported threshold values were considered. Newly introduced lithium disilicate glass-ceramics had adequate flexural strength as compared to the precursor material.
Trueness of crowns fabricated by using additively and subtractively manufactured resin-based CAD-CAM materials
(Elsevier, 2022) Çakmak, Gülce; Rusa, Ana Maria; Dönmez, Mustafa Borga; Akay, Canan; Kahveci, Çiğdem; Yılmaz, Burak
Statement of problem: Advancements in digital dental technologies have enabled the use of different resin-based materials that can be fabricated either additively or subtractively. However, knowledge on the fabrication trueness of these materials is scarce. Purpose: The purpose of this in vitro study was to investigate the trueness of crowns fabricated by using different resin-based computer-aided design and computer-aided manufacturing (CAD-CAM) materials. Material and methods: A complete crown for a mandibular right first molar with a 30-?m cement space was designed in standard tessellation language (STL) format. This master STL (MC-STL) was used to fabricate 40 complete crowns with 4 different resin-based CAD-CAM materials and either additive (Crowntec [MS]) or subtractive techniques (Brilliant Crios [BC], breCAM.monoCOM [PMMA], and G-CAM [GR]; n=10). All crowns were digitized with an intraoral scanner (CEREC Primescan SW 5.2) to generate their STL files (TC-STLs). MC-STL and TC-STLs were transferred into a 3-dimensional analysis software program (Medit Link v2.4.4), and a trueness (overall, external, occlusal, intaglio occlusal, and marginal) analysis was performed by using the root mean square (RMS) method. The Kruskal-Wallis and Dunn tests were performed to analyze data (?=.05). Results: The test groups had significantly different deviations on all surfaces (P?.001). MS crowns had higher overall (P?.007) and external surface (P?.001) deviations than GR and PMMA crowns, while the differences between GR and PMMA crowns were not significant (P?.441). BC crowns had higher external surface deviations than GR crowns (P=.005), higher occlusal deviations than GR and MS crowns (P?.007), and higher intaglio occlusal deviations than GR and MS crowns (P?.009). However, BC crowns had lower marginal deviations than MS and GR crowns (P?.018). Conclusions: The brand of resin-based CAD-CAM materials affected the trueness of crowns. Additively manufactured crowns (MS) mostly had lower overall and external surface trueness than the other groups. Nevertheless, the deviation values of occlusal, intaglio occlusal, and marginal trueness were generally small; thus, the effect of the tested materials on clinical crown fit may be negligible. © 2022 Editorial Council for the Journal of Prosthetic Dentistry
Effect of measurement techniques and operators on measured deviations in digital implant scans
(ELSEVIER, 2022) Çakmak, Gülce; Dönmez, Mustafa Borga; Akay, Canan; De Silva, Marcella Paula; Mangano, F. G.; Abou-Ayash, S.; Yılmaz, Burak
Objectives: To evaluate the effect of different measurement techniques and operators on measured deviations in in vitro implant scans. Methods: A 2-piece system that comprises a healing abutment (HA) and a scan body (SB) was mounted onto an implant at right first molar site of a polymethylmethacrylate mandibular dentate model. Model was digitized by using an industrial scanner (reference model scan, n=1) and an intraoral scanner (test scan, n=20). All standard tessellation language files were imported into a 3-dimensional analysis software and superimposed. Three operators with similar experience performed circle-based and point-based deviation analyses (n=20). Deviations measured with different techniques were compared with paired samples t-test within each operator, while the reliability of the operators was assessed by using F-tests for both technqiues (?=.05). Results: Point-based technique resulted in lower deviations than circle-based technique for all operators (P=.001) with to higher reliability among operators (ICC=.438, P=.001). The correlation among the operators was nonsignificant when circle-based technique was used (ICC=.114, P=.189). Conclusion: Lower deviations were detected with the point-based technique. In addition, different operators' measurements had higher correlation when point-based technique was used compared with circle-based technique. Clinical significance: Point-based technique may be preferred over circle-based technique for research studies on scan accuracy of implants, given its higher reliability. The accuracy of measured deviations may increase if the number of planes are increased, which can facilitate point generation at different surfaces of the scan body.
The trueness of an intraoral scanner in scanning different post space depths
(Elsevier Science, 2022) Elter, Bahar; Diker, Burcu; Tak, Önjen
The trueness of an intraoral scanner in scanning different post space depths
In vitro scan accuracy and time efficiency in various implant-supported fixed partial denture situations
(Elsevier, 2022) Abou Ayash, Samir; Mathey, Amber; Gäumann, Fabio; Mathey, Ayşe; Dönmez, Mustafa Borga; Yılmaz, Burak
In vitro scan accuracy and time efficiency in various implant-supported fixed partial denture situations
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, Burak
Purpose 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.
Prosthetic complications with monolithic or micro-veneered implant-supported zirconia single-unit, multiple-unit, and complete-arch prostheses on titanium base abutments: a single center retrospective study with mean follow-up period of 72.35 months
(WILEY, 2022) Saponaro, Paola C.; Karasan, Duygu; Dönmez, Mustafa Borga; Johnston, William Michael; Yılmaz, Burak
Background The influence of prosthetic design on prosthetic complications when monolithic or micro-veneered zirconia prostheses are supported with titanium base (ti-base) abutments is not well-known. Purpose The purpose of this single center, retrospective study was to assess the prevalence of prosthetic complications with monolithic or micro-veneered single-unit, multi-unit, and complete-arch zirconia prostheses supported with ti-base abutments (implant level or multi-unit abutment level). Material and Methods This study retrospectively evaluated the electronic health record (EHR) of participants who received either monolithic or micro-veneered implant-supported single-unit, multi-unit, and/or complete-arch prostheses supported by ti-base or zirconia-ti-base hybrid abutments delivered between the years 2010 and 2021. Data were analyzed by using logistic regression and Exact Mantel-Haenszel chi-square test (alpha = 0.05) to assess the clinical performance of prostheses and complications including crown decementation, feldspathic porcelain chipping, prosthesis fracture, zirconia-ti-base hybrid abutment decementation, abutment screw loosening, screw fracture, abutment fracture, implant loss, and prosthesis remake. Results The study included 94 participants (50 female, 44 male) with a mean age of 59.5 years (range: 24-101 years of age). The retrospective EHR evaluation yielded 82 single-unit, 51 multi-unit, and 20 complete-arch prostheses on 325 implants. Among 153 prostheses delivered, 108 were micro-veneered (47 single-unit, 41 multi-unit, and 20 complete-arch prostheses) and 45 were monolithic. The average duration was 72.35 months (6.02 years) with a follow-up period of 5-132 months. From the time of insertion to the time of EHR review, of 153 prostheses, 78.43% did not exhibit any prosthetic complication. However, 33 prostheses (21.57%) from 29 participants (30.85%) had at least one prosthetic complication. Only four patients (4.25%) experienced two or more prosthetic complications. Prosthetic design affected the probability of having a complication (p = 0.005); complete-arch prostheses had higher probability (p <= 0.028). Single-unit prostheses had lower probability of complication than multi-unit prostheses (p = 0.005). The most commonly observed complication was fracture of veneering material (5.88%) followed by prosthetic screw loosening (4.57%) and decementation between the zirconia and the ti-base abutment (2.61%). Micro-veneered complete-arch prostheses had higher probability of having chipping than that of not having (p < 0.001), and other micro-veneered prosthetic designs had similar probability of chipping with that of complete-arch prostheses (p >= 0.082). Frequency of chipping was affected by veneering (p < 0.001). Monolithic prostheses had lower probability of chipping than micro-veneered prostheses, regardless of the prosthetic design (p < 0.001). Conclusions The frequency of prosthetic complications varied depending on prosthetic design. Complete-arch prostheses had the highest probability of complications while the single-unit prostheses had the lowest. Micro-veneered prostheses had higher probability for chipping than monolithic prostheses. Probability of chipping was similar for micro-veneered single-unit, multi-unit, and complete-arch zirconia prostheses.
Influence of cement shade, ceramic thickness, and airborne-particle abrasion of titanium surface on the final color of monolithic lithium disilicate glass-ceramic hybrid-abutment systems in vitro
(QUINTESSENCE PUBLISHING CO INC, 2022) Elter, Bahar; Tak, Önjen
Objectives:The purpose of this in vitro study was to evaluate the influence of the ceramic thickness, cement shade, and airborne -particle abrasion of the titanium on the final color of titanium base cemented lithium disilicate glass-ceramic restorations.Method and materials: In total, 144 lithium disilicate glass -ce-ramic disks of three thicknesses (0.5, 1.0, and 1.5 mm) were ce-mented to airborne-particle-abraded and non -airborne-particle -abraded titanium disks with six adhesive resin cements. The color measurements were performed with a clinical spectrophotometer. The mean and standard deviation of evaluated AE values were calculated. A three-way analysis of variance (ANOVA) was used for analyzing the data. Statistical analyses were computed with a sig-nificance level of alpha = .05 using a statistical software program (Minitab 17, Minitab). Results:The 0.5-and 1-mm-thick ceramic specimens cemented with Panavia V5 Opaque showed the lowest AE values when cemented on both non-airborne-particle-abraded (5.62 +/- 1.66, 3.15 +/- 1.28) and airborne-particle-abraded (5.55 +/- 0.86, 3.16 +/- 0.49) surfaces, while the highest values were seen in the groups cemented with RelyX U200 A2 (29.22 +/- 0.83, 17.23 +/- 0.45) and Panavia V5 A2 (29.94 +/- 1.17, 16.71 +/- 0.44) on airborne -particle-abraded surfaces. For the 1.5-mm-thick ceramics, the lowest AE values were seen when Multilink MO 0 cement was used on non-airborne -particle-abraded surfaces (1.56 +/- 0.29) and when Panavia V5 Opaque was used on airborne-particle-abraded surfaces (1.56 +/- 0.66). The highest values were seen when RelyX U200 A2 (9.77 +/- 1.13), PA2 (9.24 +/- 0.25), and Multilink HO 0 (9.19 +/- 1.33) were used on airborne-particle-abraded surfaces, and when Multilink HO 0 (9.61 +/- 1.70) was used on non-airborne -parti-cle-abraded surfaces. The 1-mm-thick ceramics cemented with Multilink HO 0 showed higher AE values (12.05 +/- 1.99) for airborne- particle-abraded and non-airborne-particle-abraded (12.58 +/- 1.06) than thinner (0.5 mm) or thicker (1.5 mm) ceramics. Conclusion: Thinnest ceramic superstructures resulted in the highest AE val-ues. Cements that mask the underlying color reflect their own shade under thin superstructures. Airborne-particle abrasion of titanium surfaces increases the grayish reflectance if cement shade does not have the color masking ability.
Surface roughness and stainability of new-generation denture base materials after brushing and coffee thermocycling
(SPRINGER HEIDELBERG, 2022) Çakmak, Gülce; Dönmez, Mustafa Borga; De Paula, Marcella Silva; Akay, Canan; Chavan, Amit; Schimmel, Martin; Yılmaz, Burak
Disk-shaped specimens were prepared from additively (NX and DT), subtractively (MZ), and conventionally manufactured denture base resins (CV). Surface roughness and color coordinates were measured after polishing, simulated brushing, and coffee thermocycling, while surface roughness was also measured before polishing. Polishing reduced the surface roughness of all materials. Brushing and coffee thermocycling increased the surface roughness of only DT. CV had the highest susceptibility to consecutive brushing and coffee thermocycling as it had the highest surface roughness, which was above the clinically acceptable threshold. All materials had similar stainability; only MZ had perceptible color change after brushing. Even though stainability of tested denture base resins was similar, additively or subtractively manufactured computer-aided design and computer-aided manufacturing (CAD-CAM) resins had smoother surfaces after brushing and coffee thermocycling, regardless of the material. Therefore, complete dentures made out of these CAD-CAM resins may have favorable surface properties in the long term.
Effect of different surface treatments on the surface roughness and orthodontic bond strength of partially-stabilized zirconia
(GALENOS YAYINCILIK, 2022) Dönmez, Mustafa Borga; Demirel Ballı, Betül; Demirel, Münir; Gündoğdu, Yasemin; Kılıç, Hamdi Şükür
Objective: To investigate the effect of different surface treatments on the surface roughness (Ra) and shear bond strength (SBS) of partially stabilized zirconia (Y-PSZ) with different yttrium content.Materials and Methods: Zirconia samples were milled from 5Y-PSZ and 4Y-PSZ disks and divided into 5 groups: Control (C), sandblasting (APA), single-step self -etch primer etching (MEP), Er:YAG laser (ER), and femtosecond laser (FS) irradiation (n=11). Surface Ra was measured and metallic mandibular incisor brackets were bonded. SBS test was performed after thermocycling. Data were analyzed using two-way ANOVA and Tamhane's T2 tests (alpha=0.05).Results: Only surface treatment affected Ra and SBS (p<0.001). FS groups had the highest (p<0.001), and C groups had the lowest values Ra (p <= 0.001). MEP groups had lower Ra than ER and APA (p <= 0.002). FS and APA groups resulted in the highest SBS (p<0.001), while MEP groups achieved significantly higher SBS than ER groups (p<0.001). The C group showed the lowest SBS (p<0.001).Conclusion: Within the limitations of this in vitro study, sandblasting and FS irradiation was found to be the most effective surface treatments for metallic bracket bonding to Y-PSZ.
Influence of digital implant analog design on the positional trueness of an analog in additively manufactured models: an in-vitro study
(John Wiley and Sons Inc, 2022) Mata-Mata, Severino J.; Dönmez, Mustafa Borga; Meirelles, Luiz; Johnston, William Michael; Yılmaz, Burak
Background: Limited evidence exists regarding the accuracy of implant analog position in printed models, particularly when implant analogs with varying designs are used. Purpose: To evaluate the effect of digital implant analog (DIA) design on the trueness of their position in additively manufactured digital implant models (DIMs) and to compare with that of a conventional implant analog in a stone cast. Materials and Methods: A dentate maxillary model with a conventional implant analog (Nobel Biocare Implant Replica 4.3 mm CC RP) at left second premolar site was digitized by using a laboratory scanner (3Shape D2000) and a (SB) scan body to generate the master standard tessellation language (STL) file (M0). 12 custom trays were fabricated on M0 file and conventional polyvinylsiloxane impressions of the model were made. All impressions were poured after inserting conventional implant analogs (Nobel RP Implant Replica) (Group A). Model was then digitized with an intraoral scanner (TRIOS 3) and the same SB, and DIMs with three different DIA designs (Nobel Biocare [Group B], Elos [Group C], and NT-trading [Group D]) were generated (Dental System-Model Builder). 12 DIMs of each design were additively manufactured and corresponding DIAs were inserted. All models were digitized by using the same laboratory scanner and SB, and these STLs were transferred to a 3D analysis software (Geomagic Control X), where the STL files of the models were superimposed over M0. Linear and 3D deviations at three selected points on SB (implant-abutment connection, most cervical point on SB, and most coronal point on SB) as well as angular deviations on two planes (buccolingual and mesiodistal) were calculated. Analysis of variance (ANOVA) and Bonferroni corrected t-tests were used to analyze the trueness of implant analog positions (? = 0.05). Results: The interaction of main effects significantly affected linear (p < 0.001) and angular deviations (p = 0.020). At point 1, group D had higher deviations than groups A and B (p ? 0.015). In addition, groups A and D had higher deviations than group B at point 4 (p < 0.001). While group C had similar linear deviations to those of other groups at point 1 and point 4 (p ? 0.192), the differences among test groups at point 2 were nonsignificant (p ? 0.276). Group B had lower angular deviations than groups C (p = 0.039) and D (p = 0.006) on buccolingual plane. Conclusions: Analog design affected the trueness of analog position as proprietary, pressure/friction fit DIA (group B) had higher linear trueness than screw-retained DIA (Group D) and conventional implant analog (group A). In addition, pressure/friction fit DIA had the highest angular trueness among tested DIAs.
Surface roughness and color stability of 3D-Printed denture base materials after simulated brushing and thermocycling
(MDPI, 2022) Çakmak, Gülce; Molinero Mourelle, Pedro; De Paula, Marcella Silva; Akay, Canan; Cuellar, Alfonso Rodriguez; Dönmez, Mustafa Borga; Yılmaz, Burak
Three-dimensional (3D) printing is increasingly used to fabricate denture base materials. However, information on the effect of simulated brushing and thermocycling on the surface roughness and color stability of 3D-printed denture base materials is lacking. The aim of this study was to evaluate the effect of brushing and thermocycling on the surface roughness and color stability of 3D-printed denture base materials and to compare with those of milled and heat-polymerized denture base resins. Disk-shaped specimens (Ø 10 mm × 2 mm) were prepared from 4 different denture base resins (NextDent Denture 3D+ (ND); Denturetec (SC); Polident d.o.o (PD); Promolux (CNV)) (n = 10). Surface roughness (Ra) values were measured before and after polishing with a profilometer. Initial color coordinates were measured by using a spectrophotometer after polishing. Specimens were then consecutively subjected to simulated brushing (10,000 cycles), thermocycling (10,000 cycles), and brushing (10,000 cycles) again. Ra and color coordinates were measured after each interval. Color differences (?E00) between each interval were calculated and these values were further evaluated considering previously reported perceptibility (1.72 units) and acceptability (4.08 units) thresholds. Data were analyzed with Friedman, Kruskal–Wallis, and Mann–Whitney U tests (? = 0.05). Ra (p ? 0.051) and ?E00 (p ? 0.061) values among different time intervals within each material were similar. Within each time interval, significant differences in Ra (p ? 0.002) and ?E00 values (p ? 0.001) were observed among materials. Polishing, brushing, and thermocycling resulted in acceptable surface roughness for all materials that were either similar to or below 0.2 µm. Color of ND printed resin was affected by brushing and thermocycling. All materials had acceptable color stability when reported thresholds are considered.
A CBCT based cross sectional study on the prevalence and anatomical feature of c shaped molar among Jordanian
(Nature Research, 2022) Al Omari, Taher; AlKhader, Mustafa; Atav Ateş, Ayfer; Wahjuningrum, Dian Agustin; Dkmak, Alaa; Khaled, Waheeb; Alzenate, Hazem
The prevalence and anatomical features of C-Shaped Mandibular Second Molars (MSMs) are rarely studied in Jordanian sub-population. This study then took a part to evaluate the prevalence of C-shaped in MSMs using cone-beam computed tomography (CBCT) in the Jordanian sub-population. It used a cross-sectional design and three thousand scans collected over eight years between 2011 and 2019. The data were then reviewed for whether they were fully formed of MSMs. A total of 2037 cases that had 2845 MSMs were evaluated to identify C-shaped canals at coronal, middle, and apical sites. An oblique slicing module perpendicular to the long axis of MSMs was used to evaluate the teeth. The type and frequency of C-shaped canals, as well as the correlations between sex and side (right/left) and between sex and groove direction (buccal/lingual) were measured using the chi-square test on SPSS software at the significance level of 95%. A total of 342 teeth of 243 patients were C-shaped molars, which comprised 12% of the patient’s teeth and 99 of them as a bilateral C-shaped canal with mean age of 40 years and sex ratio of 2:1 between female and male. With the limitations of this study, the lingual groove and type 3 were the most common properties of MSM. Besides, the Jordanian population mostly had C-shaped canals.
Additive or subtractive manufacturing of crown patterns used for pressing or casting: A trueness analysis
(Elsevier Science, 2022) Çakmak, Gülce; Dönmez, Mustafa Borga; Cuellar, Alfonso Rodrigues; Kahveci, Çiğdem; Schimmel, Martin; Yılmaz, Burak
Objectives: To investigate the effect of subtractive and additive manufacturing techniques on the trueness of crown patterns used for pressing or casting. Material and Methods: A complete-coverage mandibular right first molar crown was designed in standard tessellation language (STL) format. This STL served as the control (C- STL) and was used to fabricate 30 crown patterns in 3D-printed resin (PR, ProArt Print Wax), millable wax suitable for casting (BW, ProArt CAD Wax Blue), and millable wax suitable for pressing (YW, ProArt CAD Wax Yellow) (n=10). Subtractively manufactured patterns were fabricated by using a 5-axis milling unit (PrograMill PM7), while 3D-printed patterns were fabricated by using a digital light processing-based 3D printer (PrograPrint PR5; Ivoclar Vivadent, Schaan, Liechtenstein). All fabricated patterns were digitized by using an intraoral scanner (CEREC Primescan SW 5.2) to generate test-STLs. C-STL and test-STLs were transferred into a 3D analysis software (Medit Link v 2.4.4). Trueness evaluation was performed at 4 different surfaces (external, intaglio with margin, marginal, and intaglio without margin) and for complete scan meshes (overall) by using the root mean square (RMS) method. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests (?=.05). Results: RMS values varied significantly at all surfaces (P<.001), except for marginal surface (P=.151). PR had the highest RMS values at external surface (P?.007), intaglio surfaces (with (P?.003) and without margin (P?.005)), and overall (P?.01). No significant differences were observed between YW and BW (P?.223). Conclusion: Patterns fabricated by using subtractive manufacturing exhibited high trueness. The deviation values, in general, were small, particularly at intaglio and marginal surfaces; thus, clinical difference in crown-fit may be negligible using additive or subtractive technique. Clinical Significance The fit of definitive crowns may be similar when tested crown patterns are additively or subtractively manufactured. However, crowns fabricated by using tested 3D-printed resin patterns may require more chairside adjustments compared with those fabricated by using subtractively manufactured wax patterns.
Marginal gap and fracture resistance of implant-supported 3D-printed definitive composite crowns: An in vitro study
(Elsevier Science, 2022) Dönmez, Mustafa Borga; Okutan, Yener
Objectives: To compare the marginal gap and fracture resistance of implant-supported 3-dimensional (3D) printed definitive composite crowns with those fabricated by using 3 different millable materials. Material and methods: A prefabricated abutment was digitized by using a laboratory scanner (E4 Lab Scanner) and a complete-coverage maxillary first premolar crown was designed (Dental Designer). Forty crowns were fabri- cated either by 3D printing (Saremco Print Crowntec, SP) or milling (Brilliant Crios, BC; Vita Enamic, VE; Cerasmart 270, CS) (n = 10). Baseline marginal gap values were evaluated by measuring 60 predetermined points on an abutment (15 points for each side) with a stereomicroscope at ×40 magnification. Marginal gap values were reevaluated after adhesive cementation. Load-to-fracture test was performed by using a universal testing machine. Two-way analysis of variance (ANOVA) was used to evaluate the effect of material type and cementation on marginal gap values. While Tukey HSD tests were used to compare the materials’ marginal gap values before and after cementation, the effect of cementation on marginal gap values within each material was analyzed by using paired samples t-tests. Fracture resistance data were analyzed by using 1-way ANOVA (?=0.05). Results: Material type and cementation significantly affected marginal gap values (P < .001). Regardless of cementation, SP had the lowest marginal gap values (P < .001), while the differences among milled crowns were nonsignificant (P ? .14). Cementation significantly increased the marginal gap values (P < .001). Material type did not affect fracture resistance values (F = 1.589, P = .209). Conclusion: Implant-supported 3D-printed composite crowns showed higher marginal adaptation compared with the milled crowns before and after cementation. In addition, all crowns endured similar forces before fracture.
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, Burak
Abstract: 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.
Load-to-failure resistance and optical characteristics of nano-lithium disilicate ceramic after different aging processes
(MDPI, 2022) Dönmez, Mustafa Borga; Olcay, Emin Orkun; Demirel, Münir
The aim of this study was to compare the load-to-failure resistance and optical properties of nano-lithium disilicate (NLD) with lithium disilicate (LDS) and zirconia-reinforced lithium silicate (ZLS) in different aging processes. Thirty crowns were milled from NLD, LDS, and ZLS (n = 10). All crowns were subjected to thermomechanical aging and loaded until catastrophic failure. Ten specimens from each material were prepared in two different thicknesses (0.7 mm and 1.5 mm, n = 5), and color coordinates were measured before and after coffee thermocycling. Color differences (Delta E00) and relative translucency parameter (RTP) were calculated. Data were analyzed by using ANOVA and Bonferroni-corrected t-tests (alpha = 0.05). ZLS had the highest load-to-failure resistance (p <= 0.002), while the difference between LDS and NLD was nonsignificant (p = 0.776). The interaction between material type and thickness affected Delta E00 (p < 0.001). Among the 0.7 mm thick specimens, ZLS had the lowest Delta E00 (p < 0.001). Furthermore, 1.5 mm thick ZLS had lower Delta E00 than that of 1.5 mm thick LDS (p = 0.036). Other than ZLS (p = 0.078), 0.7 mm thick specimens had higher Delta E00 (p < 0.001). The interaction between material type, thickness, and thermocycling affected RTP (p < 0.001). Thinner specimens presented higher RTP (p < 0.001). NLD and LDS had higher RTP than ZLS (p <= 0.036). However, 0.7 mm thick specimens had similar RTP after coffee thermocycling (p >= 0.265). Coffee thermocycling reduced the RTP values of 0.7 mm thick NLD (p = 0.032) and LDS (p = 0.008). NLD may endure the occlusal forces present in the posterior region. However, long-term coffee consumption may impair the esthetics of restorations particularly when thin NLD is used.
Effect of firing cycle and aging on long-term chemical degradation of monolithic CAD-CAM ceramics
(Elsevier Science, 2022) Sert, Murat; Gülce Subaşı, Meryem; Dönmez, Mustafa Borga; Çakmak, Gülce; Yiımaz, Burak
Statement of problem. Previous studies have shown the susceptibility of dental ceramics to degradation when subjected to certain media. However, knowledge on the effect of repeated firings and thermocycling on the ion elution of computer-aided design and computer-aided manufacturing (CAD-CAM) ceramics is lacking. Purpose. The purpose of this in vitro study was to compare the effect of repeated firings on the ion elution of CAD-CAM materials before and after thermocycling. Material and methods. Bar-shaped specimens were prepared from 4 different CAD-CAM materials (monolithic zirconia [Z], zirconia- reinforced lithium silicate glass-ceramic [S], lithium disilicate glass-ceramic [EX], and leucite-reinforced glass-ceramic [E]) and divided into 3 groups according to the number of repeated glaze firings (1 firing [1F], 2 firings [2F], and 4 firings [4F]). Specimens were placed into deionized water (pH 7.4) and stored at 37 C for 168 hours. Inductively coupled plasma-optic emission spectrophotometry (ICP-OES) was used to measure the baseline values of the eluted ions in immersion. The specimens were then subjected to thermocycling. Then, surface roughness (Ra) and ion elution values were measured. The Kruskal-Wallis and Mann-Whitney U tests were used to analyze the ion elution data before and after thermocycling, and the effect of thermocycling on ion elution was assessed by the Wilcoxon signed rank test. Ra data were analyzed with 2-way analysis of variance (ANOVA) and the Tukey honestly significant difference tests (a=.05). Results. Elution of some ions varied depending on the material-firing pair before (Al, As, B, Ba, Cr, Cu, Li, Mg, Na, P, and Zn) and after (Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, K, Li, Mg, Na, P, Y, and Zn) thermocycling. Before thermocycling, all firing groups within each material showed a similar number of significantly higher eluted ions. After thermocycling, the number of significantly higher eluted ions decreased in all materials, except for EX. The effect of thermocycling on the ion elution of the 1F group of Z (Al, Be, Ca, Cd, Co, Cr, Cu, K, Li, P, Y, and Zn), S (As, Be, Cd, Co, Cr, K, P, and Y), EX (B, Cu, and P), and E (B and Ba); 2F group of Z (Al, Be, Ca, Co, Cr, Cu, K, Li, P, and Y), S (Be, Cd, Co, K, Li, and Y), EX (P), and E (P); 4F group of Z (Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, K, Li, P, and Y), S (Al, Be, Cd, Co, Cr, Li, Mg, and Y), EX (Be, Ca, Cd, Co, K, Y, and Zn), and E (Ca and P) was nonsignificant (P .051). The interaction between material and repeated firings (P<.001) had a significant effect on Ra. For 1F groups, E showed the highest Ra (P .003), while Z had higher Ra than S (P=.009). For 2F groups, Z had higher Ra than S (P=.01). The differences among 4F groups were nonsignificant (P .677). An increased number of repeated firings (2F and 4F) decreased the Ra of E (P<.001). Conclusions. The effect of repeated firings and thermocycling on the chemical stability of the tested CAD-CAM materials varied. No clear trend was observed on the elution of different ions within material-firing pairs before thermocycling. However, thermocycling increased the number of significantly higher eluted ions for EX. The effect of thermocycling on the ion elution of materials varied depending on ions. Repeated firings decreased the surface roughness of E. (J Prosthet Dent 2022;-:---)
Trueness and precision of combined healing abutment-scan body system depending on the scan pattern and implant location: an in-vitro study
(Elsevier Science, 2022) Dönmez, Mustafa Borga; Çakmak, Gülce; Atalay, Sevda; Yılmaz, Hakan; Yılmaz, Burak
Objective: To test the effect of scan pattern and the location of the implant on the trueness and precision of implant scans when the combined healing abutment-scan body (CHA-SB) system is used. Material and Methods: A partially edentulous maxillary model with CHA-SBs secured on implants at 3 different sites in the left quadrant (central incisor, first premolar, and first molar) was fabricated. The model was scanned with an industrial light scanner to generate a master reference model (MRM) file. An intraoral scanner (TRIOS 3) was used to perform the test scans (n=8) with 4 different scan patterns (SP1, SP2, SP3, and SP4) with an intraoral scanner. The test scans were superimposed over the MRM file with a metrology software to calculate the distance deviations of the CHA-SB system. Data were analyzed with a 2-way analysis of variance and Tukey’s honestly significant difference tests for accuracy (?=.05). Results: Trueness (P=.001) and precision (P=.018) were significantly affected by the interaction between the scan pattern and implant location. The implant located at the central incisor site (56.7 ±35.9, 36.2 ±18.6) had higher trueness than that of located at the premolar site (94.1 ±20.4, 100.3 ±20) when SP2 (P=.037) and SP4 (P=.002) were used. The implant at the molar site (71.9 ±25.7, 147.2 ±49.7) had trueness either similar to (when SP2 was used, P?.276) or lower than (when SP4 was used, P?.024) those of others. Scans of the central incisor and premolar implants had the lowest trueness when scanned with SP1 (P?.009), while the scans of molar implant showed higher trueness when performed by using SP2 and SP3 when compared with SP4 (P?.005). When SP4 was used, the implant at the molar site had lower precision (43 ±18.9) than the implants located at the central incisor (14.1 ±11) and premolar sites (15.4 ±11.3) (P=.002). Scan patterns affected the scan precision of central incisor implant (P=.009), as SP4 (14.1 ±11) led to a higher precision than SP1 (47.7 ±27) (P=.006). Conclusions: The scan accuracy of combined healing abutment-scan body system was affected by scan pattern and implant location. SP1, which involved palatal and rotational scans resulted in the lowest trueness for central incisor and premolar implants, while the scans of the central incisor implant showed the highest trueness among different sites when SP4 was used. However, the scan pattern and implant site had a minor effect on precision. Scan precision at different implant sites only differed when SP4 was used, which resulted in the lowest precision for molar implant. Clinical Significance Rotational scanning of the palate after linear scanning of complete arch did not have any additional benefit for accuracy. In addition, rotational movements could impair the scan accuracy at the molar site.

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