scholarly journals Comparison of Retention and Fracture Load of Endocrowns Made from Zirconia and Zirconium Lithium Silicate After Aging: An in-Vitro Study

2021 ◽  
Author(s):  
Majid Sahebi ◽  
Safoura Ghodsi ◽  
Parsia Berahman ◽  
Amirhesam Amini ◽  
Somayeh Zeighami
Keyword(s):  
Retention Test ◽  
Failure Modes ◽  
In Vitro Study ◽  
Fracture Load ◽  
Resin Cement ◽  
Lithium Silicate ◽  
Compressive Test ◽  
Pull Out ◽  
Significant Difference

Abstract Background: This study aimed to compare retention and fracture load in endocrowns made from zirconium lithium silicate and translucent zirconia.Methods: Fifty-six intact human maxillary molars after being mounted in acrylic resin, were scanned to acquire biogeneric copies. Specimens underwent standard endodontic treatment and were prepared for endocrown up to 2 mm above the cementoenamel junction. The specimens were randomly divided into two groups of 28 and endocrowns were designed using biogeneric copies and milled from high-translucent zirconia disks (Zr) and zirconium lithium silicate blocks (ZLS). After cementation with dual cure resin cement, all the specimens underwent thermomechanical aging and pull-out retention test and compressive test were conducted (14 specimens were used for each test in each group, n=14) and failure modes in both tests were evaluated.Results: Independent samples t-test showed significant difference between the retention of Zr (271.5 N ±114.31) and ZLS (654.67 N ±223.17) groups (p value = 0.012). Compressive test results were also significantly different between Zr (7395.07 N ±1947.42) and ZLS (1618.3 N ±585) (p = 0.002). Failure mode of retention test was primarily adhesive failure at the cement-restoration interface in Zr group and cement-tooth interface in ZLS group. Failure modes of fracture test for Zr group were 7 non-restorable fractures and one restorable fracture while 6 specimens resisted compressive loads up to 8500 N without fracture. ZLS group showed 7 restorable and 7 non-restorable failures.Conclusions: Zr endocrowns showed significantly lower retention and higher fracture strength. Both materials seem to be suitable for fabrication of endocrown in clinical setup.

scholarly journals Fracture Resistance of Zirconia-Reinforced Lithium Silicate Ceramic Crowns Cemented with Conventional or Adhesive Systems: An In Vitro Study

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2012
Author(s):  
Gianmaria D’Addazio ◽  
Manlio Santilli ◽  
Marco Lorenzo Rollo ◽  
Paolo Cardelli ◽  
Imena Rexhepi ◽  
...  
Keyword(s):  
Mechanical Test ◽  
Testing Machine ◽  
In Vitro Study ◽  
Resin Cement ◽  
Human Tooth ◽  
Lithium Silicate ◽  
Significant Difference ◽  
Aesthetic Characteristics ◽  
Silicate Ceramic

In recent years, Zirconia-reinforced Lithium Silicate ceramic (ZLS), combining lithium-silicate and zirconia features, has shown to have excellent mechanical and aesthetic characteristics. Thus, the aim of this study was to compare the fracture strength of ZLS single crowns cemented with two different cementation techniques. Twenty crowns were realised and cemented on teeth replicas achieved from an extracted premolar human tooth. The samples were divided into two groups of 10 specimens each, Glass-ionomeric cement (GIC) group and Self-Adhesive Resin Cement (ARC) group. The mechanical test was performed using a universal testing machine. The specimens were then evaluated with a scanning electron microscope (SEM) to identify for all crowns and related abutments the pattern of fracture after the breaking point. The data obtained were statistically analysed. The mean fracture toughness values and standard deviations (±SD) were 2227 ± 382 N and 3712 ± 319 N respectively for GIC and ARC groups. In fact, t-test showed a statistically significant difference between the two groups (p < 0.001). Moreover, the SEM results demonstrated portions of abutments still attached to the crown fragments in the ARC group, whilst these were not present in the GIC group. Within the limitations of this study, these results suggest the use of adhesive cementation for ZLS crowns, which significantly increase the compressive strength of ZLS restorations compared to GIC.

scholarly journals In vitro Study of the Effect of Internal Relief Space on the Color of Ceramic Laminate Veneer

2021 ◽  
Vol 9 (D) ◽  
pp. 37-42
Author(s):  
Abd El Azeem Mostafa ◽  
Cherif A. Mohsen
Keyword(s):  
Computer Aided Design ◽  
Color Change ◽  
In Vitro Study ◽  
Resin Cement ◽  
Lithium Silicate ◽  
Standard Design ◽  
Significant Difference ◽  
Computer Aided ◽  
Cad Cam

BACKGROUND: Ceramic laminate veneer restoring is considered a challenging modality in solving various esthetic dental problems. AIM: The purpose of this study was to investigate the effect of digital internal relief space on the color of ceramic laminate veneer. MATERIALS AND METHODS: An acrylic central incisor model was prepared for ceramic laminate veneer with standard measures. The prepared acrylic resin dentotype model was scanned with intraoral computer-aided design/computer-aided manufacturing (CAD/CAM) optical scanner (CEREC Omnicam|Dentsply Sirona). The laminate veneer design was planned on the optically scanned preparation on CAD/CAM system software (CEREC software|Dentsply Sirona). Thirty ceramic laminate veneer specimens were machined from zirconia-reinforced lithium silicate (Celtra Duo blocks, Dentsply/Sirona) according to standard design by CAD/CAM system with the change of the digital internal relief space settings. The specimens were divided into three groups according to their digital internal relief settings (IRS) (20, 60, and 100 μm) (n = 10). Thirty epoxy dies were duplicated from the prepared acrylic model. The ceramic laminate veneer specimens were cemented to epoxy dies with total etch resin cement system according to the manufacture instructions. The color change (ΔE) of the cemented ceramic laminate veneer specimens was measured by spectrophotometer (Vita Easy shade, Ivoclar Vivadent AG, Schaan, Liechtenstein) using the CIELAB scale and L*, a*, b*. Each specimen was measured two times (before and after cementation). The value of color difference (ΔE) was calculated according to the formula: ΔE = [(L*2 - L*1)2 + (a*2 - a*1)2 + (b*2- b*1) 2]½. RESULTS: The highest mean value of ΔE was recorded in G100 group (1.91 ± 0.33), followed by G60 group (1.83 ± 0.09), with the least value recorded in G20 group (1.49 ± 0.49). Analysis of variance test revealed a statistically significant difference between groups (p = 0.024). CONCLUSION: The change of the digital IRS affects the color of ceramic laminate veneers.

scholarly journals Evaluation of Fracture Resistance of Reattached Vertical Fragments Bonded with Fiber-reinforced Composites: An in vitro Study

2013 ◽  
Vol 14 (4) ◽  
pp. 573-577 ◽  
Author(s):  
S Sujatha Gopal ◽  
B Shiva Kumar ◽  
P Spoorti ◽  
Jeetender Reddy ◽  
Jayaprakash Ittigi
Keyword(s):  
Fracture Resistance ◽  
In Vitro Study ◽  
Resin Cement ◽  
Vitro Study ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Polyethylene Fiber ◽  
Significant Difference

ABSTRACT Aim Aim of this in vitro study was to evaluate the resistance to fracture of vertically fractured and reattached fragments bonded with fiber-reinforced composites. Materials and methods Root canals of 45 teeth were prepared, and the teeth were intentionally fractured into two separate fragments. Control groups (n = 15 each) consisted unfractured teeth with instrumented and obturated. Fractured teeth were divided into three groups (n = 15) and were attached using (1) dual-cure resin cement (RelyX U100), (2) dual-cure resin cement and polyethylene fiber (Ribbond), (3) dual-cure resin cement and glass fibers (stick-net). Force was applied at a speed of 0.5 mm/min to the root until fracture. Results and statistical analysis Group 1 (RelyX U100 group) demonstrated lowest fracture resistance. Group 4 (control group) showed highest fracture resistance followed by group 2 (Ribbond group) and group 3 (Stick-Net groups). Statistically no significant difference was there between groups 2, 3 and 4. Conclusion Vertically fractured teeth can be treated by filling the root canal space with dual-cure adhesive resin cement or by adding polyethylene fiber or glass fiber to increase the fracture resistance of the reattached tooth fragments, an alternative to extraction. How to cite this article Kumar BS, Spoorti P, Reddy J, Bhandi S, Gopal SS, Ittigi J. Evaluation of Fracture Resistance of Reattached Vertical Fragments Bonded with Fiber-reinforced Composites: An in vitro Study. J Contemp Dent Pract 2013;14(4):573-577.

scholarly journals Biomechanics of a cemented short stem: a comparative in vitro study regarding primary stability and maximum fracture load

2021 ◽  
Author(s):  
Tobias Freitag ◽  
Karl Philipp Kutzner ◽  
Ralf Bieger ◽  
Heiko Reichel ◽  
Anita Ignatius ◽  
...  
Keyword(s):  
Bone Quality ◽  
Periprosthetic Fracture ◽  
In Vitro Study ◽  
Primary Stability ◽  
Fracture Load ◽  
Vitro Study ◽  
Short Stem ◽  
Significant Difference ◽  
Short Stems

AbstractPurposeIn total hip arthroplasty, uncemented short stems have been used more and more frequently in recent years. Especially for short and curved femoral implants, bone-preserving and soft tissue-sparing properties are postulated. However, indication is limited to sufficient bone quality. At present, there are no curved short stems available which are based on cemented fixation.MethodsIn this in vitro study, primary stability and maximum fracture load of a newly developed cemented short-stem implant was evaluated in comparison to an already well-established cemented conventional straight stem using six pairs of human cadaver femurs with minor bone quality. Primary stability, including reversible micromotion and irreversible migration, was assessed in a dynamic material-testing machine. Furthermore, a subsequent load-to-failure test revealed the periprosthetic fracture characteristics.ResultsReversible and irreversible micromotions showed no statistical difference between the two investigated stems. All short stems fractured under maximum load according to Vancouver type B3, whereas 4 out of 6 conventional stems suffered a periprosthetic fracture according to Vancouver type C. Mean fracture load of the short stems was 3062 N versus 3160 N for the conventional stems (p = 0.84).ConclusionPrimary stability of the cemented short stem was not negatively influenced compared to the cemented conventional stem and no significant difference in fracture load was observed. However, a clear difference in the fracture pattern has been identified.

scholarly journals Mechanical Pull-Out Test of a New Hybrid Fixture-Abutment Connection: An In Vitro Study

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1555
Author(s):  
Gianmaria D’addazio ◽  
Bruna Sinjari ◽  
Lorenzo Arcuri ◽  
Beatrice Femminella ◽  
Giovanna Murmura ◽  
...  
Keyword(s):  
Surface Modification ◽  
In Vitro Study ◽  
Mean Value ◽  
Vitro Study ◽  
Test Machine ◽  
Pull Out ◽  
Significant Difference ◽  
Implant Abutment ◽  
New Type

Implant abutment connection was described among the main causes of peri-implant bone resorption. The aim of this in vitro study was to test the coupling capacity, the surface modification of a new hybrid connection and the influence of repeated connection activations caused during the main clinical and laboratory phases. A total of 40 implant-abutment screw retained systems with 10°-conical and internal hexagon connection were tested. The connection was screwed, fixed to the universal test machine, removed the screw and a pull-out test was performed. Test was repeated five times in succession. Also Scanning Electron Microscopy (SEM) was used to detect microscopically surface modification. Analysis of variance and Tukey tests were used for the statistical analysis. Pull-out test reveals a mean value of 131.35 ± 16.52 Newton Centimeter (N·cm). For each single activation, results from first to fifth were: 113.9 ± 13.02, 126.1 ± 12.81, 138.11 ± 15.15, 138.8 ± 11.90 and 140 ± 12.99 N·cm. A statistically significant difference between the measurements and an increase in the removal force was shown. The collected data supports the use of this new type of connection, resulting in a very strong interface between implant and abutment. Also, repeated activation of connection can promote a better coupling of the implant-abutment interface.

scholarly journals Incorporation of Arginine to Commercial Orthodontic Light-Cured Resin Cements—Physical, Adhesive, and Antibacterial Properties

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4391
Author(s):  
Saulo Geraldeli ◽  
Lucas de Almeida Maia Carvalho ◽  
Isaac Jordão de Souza Araújo ◽  
Maurício Bottene Guarda ◽  
Marcelle M. Nascimento ◽  
...  
Keyword(s):  
Shear Bond Strength ◽  
Testing Machine ◽  
Antibacterial Properties ◽  
In Vitro Study ◽  
Resin Cement ◽  
Preventive Strategy ◽  
Resin Cements ◽  
Mean Values ◽  
Significant Difference

(1) Background: The amino acid arginine is now receiving great attention due to its potential anti-caries benefits. The purpose of this in vitro study was to evaluate the shear bond strength (SBS), ultimate tensile strength (UTS), and antimicrobial potential (CFU) of two arginine-containing orthodontic resin cements. (2) Methods: Forty bovine incisors were separated into four groups (n = 10): Orthocem, Orthocem + arginine (2.5 wt%), Transbond XT, and Transbond XT + arginine (2.5 wt%). The brackets were fixed to the flat surface of the enamel, and after 24 h the SBS was evaluated using the universal testing machine (Instron). For the UTS test, hourglass samples (n = 10) were made and tested in a mini-testing machine (OM-100, Odeme). For the antibacterial test (colony forming unit-CFU), six cement discs from each group were made and exposed to Streptococcus mutans UA159 biofilm for 7 days. The microbiological experiment was performed by serial and triplicate dilutions. The data from each test were statistically analyzed using a two-way ANOVA, followed by Tukey’s test (α = 0.05). (3) Results: The enamel SBS mean values of Transbond XT were statistically higher than those of Orthocem, both with and without arginine (p = 0.02033). There was no significant difference in the SBS mean values between the orthodontic resin cements, either with or without arginine (p = 0.29869). The UTS of the Transbond XT was statistically higher than the Orthocem, but the addition of arginine at 2.5 wt% did not influence the UTS for either resin cement. The Orthocem + arginine orthodontic resin cement was able to significantly reduce S. mutans growth, but no difference was observed for the Transbond XT (p = 0.03439). (4) Conclusion: The incorporation of arginine to commercial orthodontic resin cements may be an efficient preventive strategy to reduce bacterial growth without compromising their adhesive and mechanical properties.

scholarly journals Fracture Strength of Monolithic Zirconia Crowns with Modified Vertical Preparation: A Comparative In Vitro Study

2021 ◽  
Author(s):  
Marwah Ismael Abdulazeez ◽  
Manhal A. Majeed
Keyword(s):  
Fracture Strength ◽  
In Vitro Study ◽  
Fracture Load ◽  
Significant Difference ◽  
Zirconia Crowns ◽  
Group A ◽  
Monolithic Zirconia ◽  
Bonferroni Test ◽  
Group B

Abstract Objective The aim of this study was to evaluate the influence of different marginal designs (deep chamfer, vertical, and modified vertical with reverse shoulder) on the fracture strength and failure modes of monolithic zirconia crowns. Materials and Methods Thirty sound human maxillary first premolar teeth with comparable size were used in this study. The teeth were divided randomly into three groups according to the preparation design (n = 10): (1) group A: teeth prepared with a deep chamfer finish line; (2) group B: teeth prepared with vertical preparation; and (3) group C: teeth prepared with modified vertical preparation, where a reverse shoulder of 1 mm was placed on the buccal surface at the junction of middle and occlusal thirds. All samples were scanned by using an intraoral scanner (CEREC Omnicam, Sirona, Germany), and then the crowns were designed by using Sirona InLab 20.0 software and milled with a 5-axis machine. Each crown was then cemented on its respective tooth with self-adhesive resin cement by using a custom-made cementation device. A single load to failure test was used to assess the fracture load of each crown by using a computerized universal testing machine that automatically recorded the fracture load of each sample in Newton (N). Statistical Analysis The data were analyzed statistically by using one-way analysis of variance test and Bonferroni test at a level of significance of 0.05. Results The highest mean of fracture load was recorded by chamfer (2,969.8 N), which followed by modified vertical (2,899.3 N) and the lowest mean of fracture load was recorded by vertical (2,717.9 N). One-way ANOVA test revealed a significant difference among the three groups. Bonferroni test showed a significant difference between group A and group B, while a nonsignificant difference was revealed between group C with group A and group B. Conclusion Within the limitations of this in vitro study, the mean values of fracture strength of monolithic zirconia crowns of all groups were higher than the maximum occlusal forces in the premolar region. The modification of the vertical preparation with a reverse shoulder placed at the buccal surface improved the fracture strength up to the point that it was statistically nonsignificant with the chamfer group.

scholarly journals Retention of Cast Posts Cemented with Two Commonly Used Conventional and Two Resin Cements and the Mode of Root Fracture Following Their Removal

2021 ◽  
Author(s):  
Azadeh Hesarkhani ◽  
Farnoush Fotovat ◽  
Fatemeh Saneian ◽  
Hosein Akbari ◽  
Hanif Allahbakhshi
Keyword(s):  
Zinc Phosphate ◽  
Testing Machine ◽  
Resin Cement ◽  
Endodontically Treated Teeth ◽  
Root Fracture ◽  
Universal Testing Machine ◽  
Pull Out ◽  
Universal Testing ◽  
Significant Difference

Objectives: This study aimed to compare the retention of cast posts cemented with four types of cements and assess the mode of root fracture following their removal. Materials and Methods: In this in vitro, experimental study, 48 upper central incisors were randomly divided into 4 groups of 12, and were endodontically treated. The fabricated cast posts in each group were cemented with zinc phosphate (Masterdent), glass ionomer (GI; Meron), Meta resin cement, and Panavia SA resin cement. A device was customized for post removal by a universal testing machine similar to WAM X pliers. The retention of cemented posts was measured by the pull-out test in a universal testing machine. Next, the teeth were macroscopically and microscopically inspected regarding the occurrence and sites of catastrophic fracture, cracks, or craze lines. Quantitative and qualitative data were analyzed by ANOVA, and Chi-square test, respectively (P<0.05). Results: ANOVA showed a significant difference in the mean retention of cements (P<0.001). Panavia provided the highest retention (278.6±34.9 N) followed by zinc phosphate (221.9±28.88 N), GI (161.3±60.7 N), and Meta (140.4±66.54 N). There was no significant difference between the groups regarding the pattern of root fracture (P=0.39). However, site and extent of fractures were significantly different among the groups (P<0.05). Conclusion: The conventional cements provided optimal retention and caused less root damage after post removal. Thus, cements providing adequate retention and allowing easier post removal are recommended for use in endodontically treated teeth with a possibility of requiring retreatment.

scholarly journals Micro-shear bond strength of bioactive cement to translucent zirconia after thermocycyling: a comparative in-vitro study

2020 ◽  
Vol 23 (1) ◽  
Author(s):  
Menna Ahmed ElGendy ◽  
Ihab Mosleh ◽  
Hanaa Zaghloul
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
In Vitro Study ◽  
Resin Cement ◽  
Zirconia Ceramic ◽  
Control Group ◽  
Significant Difference ◽  
Before And After

Objective: the purpose of the study was to evaluate the micro-shear bond strength of different cements to translucent zirconia before and after thermocycling aging. Material and methods: Twelve translucent zirconia ceramic discs were used in the study. Specimens were sandblasted using 50 ‎μm aluminum oxide (Al2O3) particles. The specimens were divided into three groups (n = 4) according to the cement type: Panavia resin cement (control group), resin modified glass ionomer (RMGI), and Activa bioactive cement. Each group was further sub-divided into two equal subgroups (n = 2) according to whether the specimens were subjected to thermocycling or not. Thermocycling was performed in distilled water at 5000 cycles between 5 oC - 55 oC. The micro-shear bond strength test (μSBS) was measured using universal testing machine. Kruskal-Wallis test was used to compare between the three cements. Dunn’s test was used for pair-wise comparisons when Kruskal-Wallis test is significant. Mann-Whitney U test was used to compare between micro-shear bond strength before and after thermocycling P ≤ 0.05. Results: In non-aged subgroups, there was no significant difference between Panavia and Activa; both showed significantly the highest mean μSBS values (22.9 MPa, 31.3 MPa respectively). While, RMGI showed the lowest μSBS values (4.7 MPa).  In thermocycled subgroups, Panavia showed significantly the highest mean μSBS values (32.2 MPa). There was no significant difference between RMGI and Activa; both showed the lowest significant mean μSBS values (3.2 MPa and 8.7 MPa respectively). Conclusions: RMGI and Activa couldn’t be considered long-term reliable materials for cementing zirconia. However, Panavia provided the most durable bond to zirconia.KEYWORDSBioactive cement; Micro-shear bond strength; Resin cement; Translucent zirconia.

scholarly journals Effect of Various Veneering Techniques on Bond Strength and Colour Stability of Zirconia / Veneering Ceramic after Hydrothermal Aging

2021 ◽  
Vol 10 (39) ◽  
pp. 3474-3479
Author(s):  
Rafat Sasany ◽  
Duygu Sarac ◽  
Goknil Ergun Kunt
Keyword(s):  
Bond Strength ◽  
In Vitro Study ◽  
Resin Cement ◽  
Colour Stability ◽  
Hydrothermal Aging ◽  
Significant Difference ◽  
Before And After ◽  
Cad Cam ◽  
Ceramic Restorations

BACKGROUND The purpose of this in-vitro study was to compare the colour stability and bond strength of zirconia-based ceramic restorations after hydrothermal aging using conventional layering, heat-pressing, and multilayer veneering techniques. METHODS One hundred twenty specimens’ core (15 x 10 x 0.7) was fabricated from A2-shade zirconia CAD-CAM blocks (IPS e.max ZirCAD). Specimens were divided into 4 groups for veneering (N = 30): [(layering group (L), IPS e.max ceram), (heat – pressing group (P), IPS press), and multilayer group, IPS e max Cad for 2 different types of cement (cemented with RelyX U200 (M1) and PANAVIA SA (M2))]. Aging was performed for (5 - 55°C, 5000). Colour coordinates before and after aging were measured to calculate colour differences (ΔE00). The shear bond strength test was performed with a universal test unit. The data were analysed using the analysis of variance (ANOVA) and Tukey’s Honest Significant Difference test (alpha = 0.05). RESULTS Significant differences were found between the groups in bond strength (P < 0.001). Group M1 had the highest bond strength while Group L had the lowest bond strength. In terms of ΔE00 values, there were significant variations between the groups (P < 0.001). Group M1 had the highest colour stability, while Group M2 had the lowest colour stability. CONCLUSIONS The method of fabrication had an impact on the power of the bond between veneering ceramic and zirconia, as well as its colour stability. The restoration fabricated by a multilayer technique was cemented by resin cement (Rely X U200 Automix) which was found to be more resistant and colour stable. KEY WORDS Veneers, Heat-Press Technique, Bond Strength, Colour Different, Hydrothermal Aging.

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