Fracture resistance of maxillary premolars restored with different endocrown designs and materials after artificial ageing

Ahmed, Mohamed A. A.; Kern, Matthias; Mourshed, Bilal; Wille, Sebastian; Chaar, Mohamed Sad

doi:10.2186/jpr.jpr_d_20_00082

Cited by 32 publications

(63 citation statements)

References 56 publications

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“…Another research implies our findings by Ahmed et al who reported that the design with circumferential ferrule preparation increased fracture values for the two different treating modalities (post, core, crown and endocrown) with two different ceramic materials (zirconia and lithium disilicate) [37] .…”

Section: Discussionsupporting

confidence: 86%

Efficacy of preparation design on fracture resistance of hybrid-ceramic endo-crown on premolars: An in vitro study

Magdy¹,

Mahallawi²,

Nabil³

2023

Int. J. Appl. Dent. Sci.

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The present study aims to evaluate the effect of different preparation designs on fracture resistance and failure mode of hybrid nanoceramic endocrown on premolars. Methodology: Fourteen endodontically treated maxillary premolars were prepared to receive a hybrid nanoceramic endocrown restorations and divided into 2 groups according to the preparation designs (butt joint and 2 mm ferrule). The endocrown restorations were cemented to the prepared teeth using dual cure adhesive resin cement. All specimens were subjected to a compressive force 5KN until fracture occurs by using universal testing machine. The maximum compressive force was recorded for all specimens, then failure mode of all samples were examined visually and photographically. All repairable samples were examined for extension of the cracks using scanning electron microscope. Results: Endocrowns with ferrule preparation recorded a highly statistically significant difference with the higher mean value of fracture resistance (1911.57 ± 341.29 N), compared to the endocrowns with butt joint which recorded the lower mean value of fracture resistance (1192.70±196.04 N). Regarding the failure mode; endocrowns with ferrule design showed a high percent of catastrophic failure while butt joint showed more repairable failure. Conclusion: Endocrowns with ferrule design showed a higher fracture resistance value but with a high percent of catastrophic failure mode compared to butt joint design that showed lower fracture resistance value with mostly repairable mode of failure.

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Section: Discussionsupporting

confidence: 86%

Efficacy of preparation design on fracture resistance of hybrid-ceramic endo-crown on premolars: An in vitro study

Magdy¹,

Mahallawi²,

Nabil³

2023

Int. J. Appl. Dent. Sci.

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“…4 , higher stresses were observed in the cervical margin area of the shoulder margin compared with the flat joint margin; this might significantly increase the risks of the debonding of the restoration. In addition, clinical studies have revealed some difficulties during the fabrication of endocrown with shoulder margin, owing to the limited milling area between the pulpal inlay and proximal axial ferrule walls [ 41 ]. As such, the butt joint margin presents better protection of the adhesive interface and restoration from detachment.…”

Section: Discussionmentioning

confidence: 99%

Influence of margin design and restorative material on the stress distribution of endocrowns: a 3D finite element analysis

et al. 2022

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Background This study aimed to evaluate the stress distributions in endocrown restorations as applied to endodontically treated teeth (ETT), according to the factors of “margin design” (four levels) and “restorative material” (six levels). Methods Four 3D-finite elements models were constructed for endocrown restored molars considering different margin designs. Model A was prepared with a flat butt joint margin and received an endocrown with a 2.0-mm occlusal thickness. Model B was prepared with a 20° bevel margin and received an endocrown with a 2.0-mm occlusal thickness. Model C was prepared with an axial reduction and 1-mm shoulder margin and received an endocrown with a 2.0-mm occlusal thickness. Model D was prepared with an anatomic margin and received an endocrown with a 2.0-mm occlusal thickness. The following endocrown materials were used: In-Ceram Zirconia (Zr), Vita Suprinity (VS), IPS Empress (IE), Grandio blocs (GR), VisCalor bulk (VS), and CopraPeek Light (CP). The Load application (600 N) was performed at the food bolus and tooth surface during the closing phase of the chewing cycle. The results for the endocrown and tooth remnants were determined according to the von Mises stress. The failure risk of the cement layer was also calculated based on the normal stress criterion. Results Model D (with an anatomic margin) showed the greatest stress concentrations, especially in the irregular and sharp angles of the restoration and tooth remnants. The stress concentrated on the dentin was significantly lower in Model B with a 20° bevel margin (20.86 MPa), i.e., 1.3 times lower than the other three margin designs (27.80 MPa). Restorative materials with higher elastic moduli present higher stress concentrations inside the endocrown and transmit less stress to the cement layer, resulting in lower bonding failure risks. In contrast, materials with an elastic modulus similar to that of dentin presented with a more homogeneous stress distribution on the whole structure. Conclusions An endocrown with a 20° bevel margin design could be a favorable preparation option for ETT. Composite resins (GR and VC) exhibit a more even stress distribution, and seem to be more promising materials for endocrown molars.

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“…16 Conducting thermal and dynamic mechanical loading prior to the fracture resistance test is considered clinically relevant as it might significantly reduce the fracture resistance of ceramic retorations. 17,18 Only one previous study 19 subjected lithium disilicate endocrowns to high thermomechanical cycling combining 5000 thermal cycles and a 1.2 million dynamic loading cycles imitating 5 years of clinical service. 20 However this latter study was performed on premolar teeth.…”

Section: Discussionmentioning

confidence: 99%

Effect of intra-chamber extension of lithium disilicate endocrowns on the fracture resistance and failure modes in endodontically treated molars (In-Vitro study)

Mankabady

Ibrahim

Halim

2022

Egyptian Dental Journal

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Statement of problem:Although endocrowns have proven their clinical success in many situations, the intra-chamber endocrown extension and the proportion between the clinical crown height and the radicular stump and their effects on their fracture resistance and mode of failure have not yet been verified.Purpose: Assess the effect of intra-chamber extension of lithium disilicate endocrowns on the fracture resistance and failure modes in endodontically treated molars after thermo-mechanical loading.Material and Methods: Forty extracted molar teeth were selected and divided into 5 groups (n=8) as follows: unprepared natural teeth (NAT; control); post and core supported crowns (PCC); teeth with 4 mm intra-chamber extension (EC4); 2 mm intra-chamber extension (EC2); 1 mm intra-chamber extension (EC1). Endocrowns were subjected to 5000 thermal cycles then 1,200,000 chewing cycles. Surviving specimens were vertically loaded in a universal testing machine until fracture. Data were analyzed by 1-way ANOVA, followed by pair-wise comparaisons with the Bonferroni post-hoc test (p ≤ 0.05). The mode of failure was determined by visual inspection.Results: Natural teeth had statistically significantly lower fracture resistance than groups with crowns (p= 0.002). However, there were no statistically significant differences between the crown groups with mean fracture resistance ranging from 2502.5 N to 2843.8 N. Endocrowns exhibited mainly unfavorable fracture failure. The amount of teeth destruction related to the group EC4 was less than that related to the group EC1. Conclusions:Endocrowns with greater intra-chamber extension provided insignificantly higher fracture resistance but more protection of underlying tooth structure than endocrowns with lesser extension.

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Fracture resistance of maxillary premolars restored with different endocrown designs and materials after artificial ageing

Cited by 32 publications

References 56 publications

Efficacy of preparation design on fracture resistance of hybrid-ceramic endo-crown on premolars: An in vitro study

Efficacy of preparation design on fracture resistance of hybrid-ceramic endo-crown on premolars: An in vitro study

Influence of margin design and restorative material on the stress distribution of endocrowns: a 3D finite element analysis

Effect of intra-chamber extension of lithium disilicate endocrowns on the fracture resistance and failure modes in endodontically treated molars (In-Vitro study)

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