Flexural strength of small connector designs of zirconia-based partial fixed dental prostheses

Hamza, Tamer; Attia, Mazen A.; El-Hossary, Mohamed Mahmoud Khalil; Mosleh, I; Shokry, Tamer E.; Wee, Alvin G.

doi:10.1016/j.prosdent.2015.06.022

Cited by 29 publications

(32 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The latter contributes to the propagation of the existing flaws created by the sharp milling or post‐milling disc separation, leading to fracture at relatively moderate loads. These findings are in agreement with previous studies, which concluded that three‐unit FDPs fail at lower load to fracture if they are shaped with a sharp connector design compared to round symmetrical connector designs …”

Section: Discussionsupporting

confidence: 93%

Load‐Bearing Capacity of Monolithic Zirconia Fixed Dental Prostheses Fabricated with Different Connector Designs and Embrasure Shaping Methods

Bakitian

Seweryniak

Papia

et al. 2018

Journal of Prosthodontics

View full text Add to dashboard Cite

Purpose To investigate the load‐bearing capacity and failure mode of monolithic zirconia fixed dental prostheses (FDPs) fabricated with different connector designs and embrasure shaping methods. Materials and Methods Seventy four‐unit zirconia FDPs (with two premolar pontics) were fabricated and divided into seven groups (n = 10) according to the different connector designs gained by using different embrasure shaping methods. The groups were as follows: monolithic FDPs fabricated with sharp embrasures, monolithic FDPs fabricated with blunt embrasures, monolithic FDPs fabricated with blunt embrasures and no occlusal embrasures, two groups of monolithic FDPs fabricated with blunt embrasures and interproximal separations made with diamond discs at the soft stage and at the fully sintered stage, and monolithic FDPs fabricated with blunt embrasures and interproximal separation accentuated by localized porcelain build‐up. A final group was used as a control group, where fully veneered traditional zirconia FDPs were fabricated with default milling settings. The FDPs were artificially aged and loaded to fracture. Load to fracture and failure modes were analyzed by one‐way ANOVA, Tukey's post hoc test, and Fisher exact test (α = 0.05). Results The FDPs fabricated with interproximal porcelain separation showed significantly the highest load to fracture (1038 N ± 82) of all groups (p < 0.001), with no significant difference compared to the FDPs with no occlusal embrasures (934 N ± 175; p ˃ 0.29). The FDPs fabricated with blunt embrasures showed significantly higher load to fracture (873 N ± 115) compared to the FDPs in the control group (689 N ± 75) and the FDPs with sharp embrasures (417 N ± 87; p < 0.001). There were no significant differences between the FDPs with sharp embrasures (417 N ± 87) and the FDPs with interproximal disc separations (467 N ± 94; p ˃ 0.23). Failure mode of the FDPs fabricated with sharp embrasures and interproximal disc separations differed significantly compared to the FDPs in the other groups (p < 0.001). Conclusions Sharp embrasures and interproximal separations made with diamond discs significantly decrease the load‐bearing capacity of monolithic zirconia FDPs compared to FDPs made with blunt embrasures. Blunt embrasures in combination with localized porcelain build‐up produce FDPs with high load‐bearing capacity in relation to loads that might be expected under clinical use.

show abstract

Section: Discussionsupporting

confidence: 93%

Load‐Bearing Capacity of Monolithic Zirconia Fixed Dental Prostheses Fabricated with Different Connector Designs and Embrasure Shaping Methods

Bakitian

Seweryniak

Papia

et al. 2018

Journal of Prosthodontics

View full text Add to dashboard Cite

show abstract

“…The present study compared the load to fracture of posterior FPDs under 2 conditions: no preloading and thermomechanical loading. Several authors have performed static load tests to study the load to fracture of ceramic materials and suggest that compressive testing is an adequate method . However, other authors recommend the use of artificial aging to reproduce oral environment conditions for in vitro studies of ceramic materials, as they may involve a decrease in fracture resistance.…”

Section: Discussionmentioning

confidence: 99%

“…Several authors have performed static load tests to study the load to fracture of ceramic materials and suggest that compressive testing is an adequate method. 1,9,27,28,31 However, other authors 3,10,12,19,[22][23][24]29,[32][33][34][35][36][37][38][39] recommend the use of artificial aging to reproduce oral environment conditions for in vitro studies of ceramic materials, as they may involve a decrease in fracture resistance. Nevertheless, fewer studies comparing static loading with some type of artificial aging have been reported, 7,19,23,24,34,35,[38][39][40] and the results are controversial.…”

Section: Discussionmentioning

confidence: 99%

Effect of Thermomechanical and Static Loading on the Load to Fracture of Metal‐Ceramic, Monolithic, and Veneered Zirconia Posterior Fixed Partial Dentures

López-Suárez

Tobar

Solá-Ruíz

et al. 2019

Journal of Prosthodontics

View full text Add to dashboard Cite

Purpose To evaluate the influence of static (not preloaded) and thermomechanical loading on the load to fracture of metal‐ceramic, monolithic and veneered zirconia computer‐aided design/computer‐aided manufacturing (CAD/CAM) posterior fixed partial dentures (FPDs). Materials and Methods One hundred standardized specimens with 2 abutments screwed onto a platform were prepared from stainless steel to receive a posterior 3‐unit FPD with an intermediate pontic. Specimens were randomly divided into 5 groups (n = 20): Metal‐ceramic (control group), Lava Zirconia system, Vita In‐Ceram YZ, IPS e.max ZirCAD, and Lava Plus. Half of the specimens of each group (n = 10) underwent no preloading, and the other half were subjected to thermomechanical loading in a masticatory simulator, and then all FPDs were loaded until fracture using a universal testing machine at a 1 mm/min crosshead speed. The load to fracture of the veneering ceramic and the load to fracture of framework (total fracture) were recorded for each specimen. Data were statistically analyzed using 2‐way ANOVA, Tukey's HSD post‐hoc test, Student's t test, and Weibull statistics, α = 0.05. Results Significant differences were recorded between the metal‐ceramic and veneered zirconia groups for the veneering ceramic load (p < 0.001; f = 36.62; f = 57.76) in no preloading and thermomechanical loading subgroups, respectively, but no differences were observed between the static and thermomechanical loading conditions. No differences were observed among the veneered zirconia groups. For the total load to fracture, significant differences were observed according to the material (p < 0.001; f = 500.8), between the metal‐ceramic and Lava Plus group and the other zirconia groups in no preloading subgroup, and between metal‐ceramic and the other groups (p < 0.001; f = 303.33) in thermomechanical loading subgroup. For the type of preloading, significant differences were observed (p = 0.02; f = 5.24) between the Lava Plus group and the other groups. Thermomechanical loading significantly decreased the fracture load of the Lava Plus group (p = 0.005). The Weibull statistics corroborated the results. Conclusions Monolithic zirconia restorations provided the highest load to fracture values among the zirconia groups tested; however, the results indicate that they must be used in the oral environment with caution, because their load to fracture was influenced by the aging simulation.

show abstract

“…The connector dimensions were 4x4 mm 2 with rounded broader radius of curvature (0.6mm) at the gingival area to enhance fracture resistance of the restoration according to multiple studies (30,31,38) .…”

Section: Discussionmentioning

confidence: 99%

“…Data were transferred to the computer connected to the milling machine to start designing. The fully anatomical IRFPD design was formed according to the manufacturer's directions and software recommendations including; 30 mm die spacer, modified ridge-lap pontic and 4x4 mm 2 connector dimensions with rounded 0.6mm radius of curvature at the gingival area (30,31) . Milling of wax patterns was then activated.…”

Section: Construction Of 20 Cad/cam Wax Patternsmentioning

confidence: 99%

Fracture Resistance and Retention of Metal-Free Inlay Retained Fixed Partial Dentures

et al. 2017

View full text Add to dashboard Cite

Statement of the problem: Conservative esthetic restorative dentistry has become an essential component in modern clinical practice. However, the inlay retained fixed partial dentures (IRFPDs) have a higher risk of fracture and dislodgement due to minimal preparations. Purpose: to compare fracture resistance and retention of Lithium disilicate (IPS e.max) and Polyetheretherketone (BioHPP) IRFPDs fabricated with heat-press technique and CAD/CAM system. Materials and Methods: Forty models, each including extracted mandibular 2 nd premolar and 2 nd molar embedded in an epoxy resin block with 10 mm intra-abutment distance representing missing mandibular 1 st molar were constructed. The premolar and molar of each model received standardized class II inlay preparations. The constructed models were randomly divided into four groups; Group (1): IPS e.max Press IRFPDs, Group (2): IPS e.max CAD IRFPDs, Group (3): BioHPP Granulates IRFPDs, and Group (4): breCAM.BioHPP IRFPDs. All IRFPDs were cemented using RelyX Ultimate adhesive resin cement. Samples were stored for 24 hours in distilled water at 37°C, and then thermocycled for 5000 cycles. Universal testing machine was used to measure fracture and dislodging loads. Samples were examined for determination of failure mode using a magnifying lens. Results: The statistically significant highest mean dislodging load value was obtained in IPS e.max Press IRFPDs, followed by IPS e.max CAD, with the least value recorded in breCAM.BioHPP. In contrast, breCAM.BioHPP IRFPDs revealed the statistically significant highest mean fracture load value, followed by BioHPP Granulates, while the least mean fracture value was recorded in IPS e.max Press. Most failure occurred in IPS e.max groups was connector fracture, while in BioHPP groups was plastic deformation. Conclusions: Retention and fracture resistance of metal-free inlayretained bridges are significantly affected by both; material type and construction method. BioHPP has significant advantages for dental applications because of higher fracture resistance and better stress distribution. The bond strength at IPS e.max/ resin cement interface is considered a reliable bond presenting better retention to IRFPDs. Being a brittle material, connector fracture is the predominant failure mode of IPS e.max IRFPDs; however, BioHPP has low elastic modulus showing plastic deformation as a predominant failure mode.

show abstract

Flexural strength of small connector designs of zirconia-based partial fixed dental prostheses

Cited by 29 publications

References 20 publications

Load‐Bearing Capacity of Monolithic Zirconia Fixed Dental Prostheses Fabricated with Different Connector Designs and Embrasure Shaping Methods

Load‐Bearing Capacity of Monolithic Zirconia Fixed Dental Prostheses Fabricated with Different Connector Designs and Embrasure Shaping Methods

Effect of Thermomechanical and Static Loading on the Load to Fracture of Metal‐Ceramic, Monolithic, and Veneered Zirconia Posterior Fixed Partial Dentures

Fracture Resistance and Retention of Metal-Free Inlay Retained Fixed Partial Dentures

Contact Info

Product

Resources

About