Fit of cobalt–chromium implant frameworks before and after ceramic veneering in comparison with CNC‐milled titanium frameworks

Svanborg, Per; Stenport, Victoria Franke; Eliasson, Alf

doi:10.1002/cre2.9

Cited by 17 publications

(21 citation statements)

References 37 publications

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“…Results below 10 µm were also found in the literature for fixed prostheses prepared by CAD/CAM in zirconia, 12 titanium, and Co-Cr. 11 In the present study, after mechanical loading, the abutments in the TI, MM, and AM groups showed similar adaptation values, and all were within the same range as those reported in the literature for external hexagon implant abutments. 37,39 Metal abutments made by CAD/CAM systems using subtractive milling techniques appear to be highly accurate.…”

Section: Discussionsupporting

confidence: 89%

Scanning Electron Microscopy Analysis of the Adaptation of Single-Unit Screw-Retained Computer-Aided Design/Computer-Aided Manufacture Abutments After Mechanical Cycling

Markarian¹,

Galles²,

França³

2018

Int J Oral Maxillofac Implants

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Purpose: To measure the microgap between dental implants and custom abutments fabricated using different computer-aided design/computer-aided manufacture (CAD/CAM) methods before and after mechanical cycling. Materials and Methods: CAD software (Dental System, 3Shape) was used to design a custom abutment for a single-unit, screw-retained crown compatible with a 4.1-mm external hexagon dental implant. The resulting stereolithography file was sent for manufacturing using four CAD/CAM methods (n = 40): milling and sintering of zirconium dioxide (ZO group), cobalt-chromium (Co-Cr) sintered via selective laser melting (SLM group), fully sintered machined Co-Cr alloy (MM group), and machined and sintered agglutinated Co-Cr alloy powder (AM group). Prefabricated titanium abutments (TI group) were used as controls. Each abutment was placed on a dental implant measuring 4.1 × 11 mm (SA411, SIN) inserted into an aluminum block. Measurements were taken using scanning electron microscopy (SEM) (×4,000) on four regions of the implant-abutment interface (IAI) and at a relative distance of 90 degrees from each other. The specimens were mechanically aged (1 million cycles, 2 Hz, 100 N, 37°C) and the IAI width was measured again using the same approach. Data were analyzed using two-way analysis of variance, followed by the Tukey test. Results: After mechanical cycling, the best adaptation results were obtained from the TI (2.29 ± 1.13 µm), AM (3.58 ± 1.80 µm), and MM (1.89 ± 0.98 µm) groups. A significantly worse adaptation outcome was observed for the SLM (18.40 ± 20.78 µm) and ZO (10.42 ± 0.80 µm) groups. Mechanical cycling had a marked effect only on the AM specimens, which significantly increased the microgap at the IAI. Conclusion: Custom abutments fabricated using fully sintered machined Co-Cr alloy and machined and sintered agglutinated Co-Cr alloy powder demonstrated the best adaptation results at the IAI, similar to those obtained with commercial prefabricated titanium abutments after mechanical cycling. The adaptation of custom abutments made by means of SLM or milling and sintering of zirconium dioxide were worse both before and after mechanical cycling.

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Section: Discussionsupporting

confidence: 89%

Scanning Electron Microscopy Analysis of the Adaptation of Single-Unit Screw-Retained Computer-Aided Design/Computer-Aided Manufacture Abutments After Mechanical Cycling

Markarian¹,

Galles²,

França³

2018

Int J Oral Maxillofac Implants

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“…Furthermore, CAD/CAM frameworks retained by implants improved the palatal obturator stability and functional results for patients with partial maxillectomy [ 11 ]. Titanium and cobalt-chromium alloys represent standard materials for CAD/CAM frameworks, with good performance and similar fit [ 12 ], while polyetheretherketone (PEEK) is an inert, non-allergenic polymeric biomaterial, indicated as a substitute for metal alloys in assorted types of prostheses and orthoses, including craniofacial prostheses [ 13 , 14 ].…”

Section: Introductionmentioning

confidence: 99%

Stress distribution on different bar materials in implant-retained palatal obturator

et al. 2020

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Implant-retained custom-milled framework enhances the stability of palatal obturator prostheses. Therefore, to evaluate the mechanical response of implant-retained obturator prostheses with bar-clip attachment and milled bars, in three different materials under two load incidences were simulated. A maxilla model which Type IIb maxillary defect received five external hexagon implants (4.1 x 10 mm). An implant-supported palatal obturator prosthesis was simulated in three different materials: polyetheretherketone (PEEK), titanium (Ti:90%, Al:6%, V:4%) and Co-Cr (Co:60.6%, Cr:31.5%, Mo:6%) alloys. The model was imported into the analysis software and divided into a mesh composed of nodes and tetrahedral elements. Each material was assumed isotropic, elastic and homogeneous and all contacts were considered ideal. The bone was fixed and the load was applied in two different regions for each material: at the palatal face (cingulum area) of the central incisors (100 N magnitude at 45°); and at the occlusal surface of the first left molar (150 N magnitude normal to the surface). The microstrain and von-Mises stress were selected as criteria for analysis. The posterior load showed a higher strain concentration in the posterior peri-implant tissue, near the load application side for cortical and cancellous bone, regardless the simulated material. The anterior load showed a lower strain concentration with reduced magnitude and more implants involving in the load dissipation. The stress peak was calculated during posterior loading, which 77.7 MPa in the prosthetic screws and 2,686 με microstrain in the cortical bone. For bone tissue and bar, the material stiffness was inversely proportional to the calculated microstrain and stress. However, for the prosthetic screws and implants the PEEK showed higher stress concentration than the other materials. PEEK showed a promising behavior for the bone tissue and for the integrity of the bar and bar-clip attachments. However, the stress concentration in the prosthetic screws may represent an increase in failure risk. The use of Co-Cr alloy can reduce the stress in the prosthetic screw; however, it increases the bone strain; while the Titanium showed an intermediate behavior.

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“…(19) This result was in agreement with that of Tiossi et al (30) who compared titanium and Co-Cr frameworks in three-unit implant retained FDPs before and after simulated porcelain firings and reported insignificant differences. Controversy, Svanborg et al (20) found that ceramic veneering resulted in minor improvement of the fit for Co-Cr full arch implant supported frameworks, the difference in the results may be attributed to the difference in the restoration type as they used full arch Co-Cr and CNC milled Ti frameworks. On the other hand, Kaleli and Saraç (21) reported that marginal discrepancy increased after porcelain application for metal ceramic restorations with Co-Cr frameworks prepared by different methods.…”

Section: Discussionmentioning

confidence: 99%

“…(18) Several studies have reported that the porcelain firing stages affect the fit of the Co-Cr restorations. (11,(19)(20)(21) Another crucial factors for the long term success of implant supported metal ceramic restoration are their mechanical resistance and structural integrity in the oral cavity. (2) The mechanical response of the functionally loaded metal ceramic restoration is dependent on the mechanical properties of the supporting metal core which rely on material composition and production method.…”

Section: Introductionmentioning

confidence: 99%

Influence of Cobalt Chromium Framework Fabrication Techniques on Marginal Accuracy and Fracture Behavior of Implant-Supported Metal Ceramic Bridges

Sallam

2017

Egyptian Dental Journal

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Statement of problem: Marginal fit and structural integrity are keys for long term success of implant supported restorations. Little information is available regarding precision of marginal adaptation and fracture behavior of implant supported metal ceramic bridges with recently introduced milled Cobalt Chromium frameworks. Aim of the study: Evaluation of marginal accuracy (before and after porcelain application) and fracture resistance of implant supported metal ceramic bridges with Cobalt Chromium (Co-Cr) frameworks fabricated using the new computer aided designing /computer aided manufacturing (CAD/CAM, soft milling/post sintering) technique in comparison to the conventional casting technique. Materials & Methods: A total of 10 epoxy resin models were constructed into which two titanium dummy implants were inserted in each model and received straight titanium abutments. 10 Co-Cr cement retained frameworks were fabricated on the implant models, 5 with the new CAD/ CAM soft milling/ post sintering technique (group I) and the other 5 with the lost wax casting technique (group II). All frameworks were veneered with porcelain by the layering technique. Vertical marginal gap distance between the Co-Cr frameworks and the implant abutments was measured using a stereo microscope at 16 predetermined points/abutment before and after porcelain application. Then metal ceramic bridges were cemented onto their corresponding abutments with temporary resin cement. Samples were loaded compressively under static vertical load till fracture in a universal testing machine with a loadcell of 5 kN at a cross-head speed of 1 mm/min. The load required to fracture was recorded in Newton. Fracture modes of all samples were visually analyzed. Data were statistically analyzed using the repeated measures ANOVA test for vertical marginal gap distance results (P<0.05) and the students t-test for fracture resistance results (P < 0.05). Results: Framework fabrication techniques as well as porcelain application was statistically insignificantly affecting the vertical marginal gap distance as indicated by the repeated measures ANOVA test (P>0.05). Bridges with CAD/CAM fabricated frameworks recorded (1056)

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Fit of cobalt–chromium implant frameworks before and after ceramic veneering in comparison with CNC‐milled titanium frameworks

Cited by 17 publications

References 37 publications

Scanning Electron Microscopy Analysis of the Adaptation of Single-Unit Screw-Retained Computer-Aided Design/Computer-Aided Manufacture Abutments After Mechanical Cycling

Scanning Electron Microscopy Analysis of the Adaptation of Single-Unit Screw-Retained Computer-Aided Design/Computer-Aided Manufacture Abutments After Mechanical Cycling

Stress distribution on different bar materials in implant-retained palatal obturator

Influence of Cobalt Chromium Framework Fabrication Techniques on Marginal Accuracy and Fracture Behavior of Implant-Supported Metal Ceramic Bridges

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