In vitro evaluation of marginal, axial, and occlusal discrepancies in metal ceramic restorations produced with new technologies

Kocaağaoğlu, Hasan; Kılınç, Halil İbrahim; Albayrak, Haydar; Kara, Meryem

doi:10.1016/j.prosdent.2016.03.013

Cited by 67 publications

(77 citation statements)

References 37 publications

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“…An error of 200 µm, which is greater than the amount of error found in the present study, was considered clinically insignificant because intraoral adjustment is easily achievable . Furthermore, an occlusal discrepancy of over 161 µm for metal‐ceramic crowns fabricated by casting, milling, and sintering has been reported . Occlusal discrepancy of this magnitude is within the range reported in the present study and further suggests that the error between virtual and mechanical articulator may not be clinically significant.…”

Section: Discussionmentioning

confidence: 99%

Accuracy of Dynamic Virtual Articulation: Trueness and Precision

Hsu

Driscoll

Romberg

et al. 2019

Journal of Prosthodontics

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Purpose To study the effects of altering condylar settings and pin openings on the trueness and precision of virtual articulators vs. mechanical articulators. Materials and Methods Maxillary and mandibular typodonts with fiducial markers were mounted on a mechanical Artex‐CR articulator, and the mandibular teeth were prepared to allow guidance solely by the posterior determinants of the articulator and the incisal table. The relationship of the mounted typodonts was preserved digitally by scanning using manufacturer transfer plate adaptors. On the mechanical articulator, pattern resin was allowed to set between the maxillary and mandibular occlusal surfaces (area #25‐30) at the endpoints of dynamic movements at 3 condylar inclinations (SCI): 10°, 30°, and 45°, n = 12/inclination, or at 3 incisal pin openings (2, 5, and 10 mm, n = 12/opening). All other articulator settings were kept constant. Resin specimens attached to the typodonts were scanned within 5 minutes of setting, then removed, and the articulated typodonts rescanned. Fixed dental prostheses (FDPs) #25‐30 were designed on the virtual articulator using identical parameters to the mechanical articulator. Dynamic virtual movements were used to sculpt the design, and a file of the design was saved. The files of both types of samples were aligned and overlaid. Interocclusal separation was measured in triplicate at the indentation created by the mesiolabioincisal point angle on the incisal edge of #8 and the mesiobucco‐occlusal point angle of #3. Trueness and precision of both types of articulators were calculated and compared using one‐way ANOVA, followed by the Tukey HSD test (α = 0.05). Results There was no statistically significant difference at altered pin openings in either trueness (F = 0.202, p = 0.37) or precision (F = 3.134, p = 0.09) for the majority of measurements. The only significant difference was in the precision between the 2 types of articulators at 5 mm incisal opening, and only at the anterior measurement point (F = 15.134, p = 0.0008); however, these differences were less than 100 μm. When the SCI was altered, there was no statistically significant difference (F = 3.624, p > 0.05) between the virtual and mechanical articulators in trueness for 5 of the 6 measurements obtained (F = 3.624, p = 0.07) or for all of the precision measurements (F = 3.529, p = 0.07). The one trueness measurement that was significantly different (F = 9.237, p = 0.006) occured at SCI of 10°, and it was less than 100 µm. Conclusions Dynamic movements on the virtual articulator were shown to be as true and precise as to the mechanical articulator. When there were deviations, these deviations were less than 100 µm and thus, these deviations may not be clinically relevant.

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Section: Discussionmentioning

confidence: 99%

Accuracy of Dynamic Virtual Articulation: Trueness and Precision

Hsu

Driscoll

Romberg

et al. 2019

Journal of Prosthodontics

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“…Kim et al [7] reported that SLM-fabricated Co-Cr alloy copings showed significantly larger marginal discrepancies than cast ones. In addition, Kocaağaoğlu et al [8] showed a significantly increased marginal discrepancy after the application of veneering ceramic in the Co-Cr alloy copings produced by SLM ( Figure 1). Therefore, at present, it cannot be ensured that dental SLM restorations have a good marginal fit both before and after ceramic veneering.…”

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confidence: 95%

“…It should also be noted that most dental metallic restorations produced by SLM need to be veneered with ceramic (porcelain) to match the color of the tooth for improved esthetic results [1]. The fracture of ceramic veneers is a common clinical problem that causes the premature failure of fixed partial dentures [8]. Therefore, a high bond strength between ceramic and metal in a ceramic-metal restoration is directly associated with the long-term clinical success of the restoration [1].…”

mentioning

confidence: 99%

“…Therefore, mechanical anisotropy should also be taken into consideration when a metal substructure for a metal-ceramic restoration is built. As stated previously, a possible change in the marginal fit of metal-ceramic restorations during the application of veneering ceramic onto an SLM substructure needs to be researched further by carefully examining the dimension and microstructure during the firing procedures [8].…”

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confidence: 99%

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Fabricating High-Quality 3D-Printed Alloys for Dental Applications

2017

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Featured Application: This article will help to find main points to be considered while applying selective laser melting technology in dentistry.Abstract: Metal additive manufacturing (AM), especially selective laser melting (SLM), has been receiving particular attention because metallic functional structures with complicated configurations can be effectively fabricated using the technique. However, there still exist some future challenges for the fabrication of high-quality SLM products for dental applications. First, the surface quality of SLM products should be further improved by standardizing the laser process parameters or by appropriately post-treating the surface. Second, it should be guaranteed that dental SLM restorations have good dimensional accuracy and, in particular, a good marginal fit. Third, a definitive standard regarding building and scanning strategies, which affect the anisotropy, should be established to optimize the mechanical properties and fatigue resistance of SLM dental structures. Fourth, the SLM substructure's bonding and support to veneering ceramic should be further studied to facilitate the use of esthetic dental restorations. Finally, the biocompatibility of SLM dental alloys should be carefully examined and improved to minimize the potential release of toxic metal ions from the alloys. Future research of SLM should focus on solving the above challenges, as well as on fabricating dental structures with "controlled" porosity.Keywords: additive manufacturing; anisotropy; dental alloy; selective laser melting Additive manufacturing (AM), also known as three-dimensional (3D) printing or rapid prototyping, is the process of joining materials to make 3D objects from digital data, usually layer upon layer [1,2]. Metal AM, especially selective laser melting (SLM), has been receiving particular attention because metallic functional structures with complicated configurations in various industrial, medical, and dental sectors can now be fabricated using this technique [1][2][3]. However, due to the complex nature of metal AM, there still exist many challenges for the successful fabrication of high-quality metallic products with favorable microstructures and properties [3]. In particular, several challenges need to be solved in order to apply the SLM technology widely in dental applications, replacing conventional techniques such as casting [1].It has been known that the SLM technique can produce 3D objects with minimal pre-processing and/or post-processing requirements [3]. In reality, however, the supporting structure created in the manufacturing stage must be manually removed after the final 3D product is completed [2,4].

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“…먼저 제작된 금속하부구조물 내면을 저점도의 실리콘 인상재 (Examixfine injection type, GC, Tokyo, Japan)로 채우고 금속 지대치에 위치시켰다. 수압으로 누르고, 5분간 경화시켰다 2,4. Light body silicone막 내부에 Regular body의 실리콘 인상재 (Examixfine regular type, GC, Tokyo, Japan)를 채우고 경화시 켰다.…”

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Comparative evaluation of marginal and internal fit of metal copings fabricated by various CAD/CAM methods

Jeong

Cho

Jung

et al. 2019

J Korean Acad Prosthodont

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Purpose:The purpose of the present study was to compare the accuracy of four different metal copings fabricated by CAD/CAM technology and to evaluate clinical effectiveness. Materials and methods: Composite resin tooth of the maxillary central incisor was prepared for a metal ceramic crown and duplicated metal die was fabricated. Then scan the metal die for 12 times to obtain STL files using a confocal microscopy type oral scanner. Metal copings with a thickness of 0.5 mm and a cement space of 50 μm were designed on a CAD program. The Co-Cr metal copings were fabricated by the following four methods: Wax pattern milling & Casting (WM), Resin pattern 3D Printing & casting (RP), Milling & Sintering (MS), Selective laser melting (SLM). Silicone replica technique was used to measure marginal and internal discrepancies. The data was statistically analyzed with One-way analysis of variance and appropriate post hoc test (Scheffe test) (α=.05). Results: Mean marginal discrepancy was significantly smaller in the Group WM (27.66 ± 9.85 µm) and Group MS (28.88 ± 10.13 µm) than in the Group RP (38.09 ± 11.14 µm). Mean cervical discrepancy was significantly smaller in the Group MS than in the Group RP. Mean axial discrepancy was significantly smaller in the Group WM and Group MS then in the Group RP and Group SLM. Mean incisal discrepancies was significantly smaller in the Group RP than in all other groups. Conclusion: The marginal and axial discrepancies of the Co-Cr coping fabricated by the Wax pattern milling and Milling/Sintering method were better than those of the other groups. The marginal, cervical and axial fit of Co-Cr copings in all groups are within a clinically acceptable range. (J Korean Acad Prosthodont 2019;57:211-8)

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In vitro evaluation of marginal, axial, and occlusal discrepancies in metal ceramic restorations produced with new technologies

Cited by 67 publications

References 37 publications

Accuracy of Dynamic Virtual Articulation: Trueness and Precision

Accuracy of Dynamic Virtual Articulation: Trueness and Precision

Fabricating High-Quality 3D-Printed Alloys for Dental Applications

Comparative evaluation of marginal and internal fit of metal copings fabricated by various CAD/CAM methods

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