Fracture Resistance of Implant Abutments Following Abutment Alterations by Milling the Margins: An In Vitro Study

2016 ◽  
Vol 42 (6) ◽  
pp. 464-468 ◽  
Author(s):  
Anuya Patankar ◽  
Mohit Kheur ◽  
Supriya Kheur ◽  
Tabrez Lakha ◽  
Murtuza Burhanpurwala

This in vitro study evaluated the effect of different levels of preparation of an implant abutment on its fracture resistance. The study evaluated abutments that incorporated a platform switch (Myriad Plus Abutments, Morse Taper Connection) and Standard abutments (BioHorizons Standard Abutment, BioHorizons Inc). Each abutment was connected to an appropriate implant and mounted in a self-cured resin base. Based on the abutment preparation depths, 3 groups were created for each abutment type: as manufactured, abutment prepared 1 mm apical to the original margin, and abutment prepared 1.5 mm to the original margin. All the abutments were prepared in a standardized manner to incorporate a 0.5 mm chamfer margin uniformly. All the abutments were torqued to 30 Ncm on their respective implants. They were then subjected to loading until failure in a universal testing machine. Abutments with no preparation showed the maximum resistance to fracture for both groups. As the preparation depth increased, the fracture resistance decreased. The fracture resistance of implant abutment junction decreases as the preparation depth increases.

2021 ◽  
Vol 9 (10) ◽  
pp. 115
Author(s):  
Amirali Zandinejad ◽  
Marta Revilla-León ◽  
Mohammad Mujtaba Methani ◽  
Leila Nasiry Khanlar ◽  
Dean Morton

(1) Background: This study compared the fracture resistance of additively manufactured monolithic zirconia and bi-layered alumina toughened zirconia crowns on implants. (2) Methods: Maxillary model with a dental implant replacing right second bicuspid was obtained. Custom abutments and full-contour crowns for additively manufactured monolithic zirconia and bi-layered alumina reinforced zirconia crowns (n = 10) were fabricated. The crowns were cemented to implant-supported zirconia abutments and the assembly fixed onto resin blocks. Fracture resistance was measured using a universal testing machine at a crosshead speed of 2 mm/min. A Kruskal–Wallis test was used to analyze the data. (3) Results: Although additively manufactured monolithic zirconia crowns demonstrated a higher mean fracture resistance than bi-layered alumina toughened zirconia crowns, statistical analysis revealed no significant difference in fracture resistance between the two groups. All specimens fractured at the implant–abutment interface. (4) Conclusions: Additively manufactured bi-layered alumina toughened zirconia crowns demonstrated similar fracture resistance to additively manufactured monolithic zirconia crowns when cemented to implant-supported zirconia abutments.


Children ◽  
2022 ◽  
Vol 9 (1) ◽  
pp. 77
Author(s):  
AlWaleed Abushanan ◽  
Rajashekhara B. Sharanesha ◽  
Bader Aljuaid ◽  
Tariq Alfaifi ◽  
Abdullah Aldurayhim

In this study, we evaluated the fracture resistance of three commercially available prefabricated primary zirconia crowns and their correlation with dimensional variance. Methods: a total of 42 zirconia crowns were selected from three companies, (1) NuSmile primary zirconia crowns, (2) Cheng Crowns zirconia, and (3) Sprig EZ crowns. The crowns were divided into two groups based on their location in the oral cavity and further divided into subgroups based on the brand. All of the samples were subjected to fracture tests using a universal testing machine. Results: the mean load observed was highest with Cheng Crowns zirconia anterior crowns (1355 ± 484) and the least load was seen with Sprig EZ anterior crowns with a mean load of 339 ± 94. The mean load observed was highest with Cheng Crowns zirconia posterior crowns (1990 ± 485) followed by NuSmile posterior crowns and the least load was seen with Sprig EZ posterior crowns with a mean load of 661 ± 184. Conclusion: the Cheng crowns showed the highest fracture resistance amongst all three groups. Overall, the zirconia crowns (anterior and posterior) tested showed optimum mechanical properties to withstand the masticatory forces.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zahraa Abdulaali Al-Ibraheemi ◽  
Huda Abbas Abdullah ◽  
Nada Abdlameer Jawad ◽  
Julfikar Haider

During restorative treatment, premolars restored with resin filling materials using the conventional incremental-fill technique take longer restoration time and undermine the integrity of the tooth. The aim of this study was to assess fracture resistance of premolars restored by various types of novel bulk-fill composite resin materials. Forty-eight (n = 48) freshly extracted sound maxillary first premolars were used in this in vitro study. The teeth were divided into six groups, each having 8 specimens. Group A (positive control) was allocated for the intact teeth. For specimens in Groups B to F, a large cavity (Class-II MOD) was prepared with a standardized dimension of cavity (3 mm depth on the pulpal floor, 4 mm at the gingival seat, and 3 mm cavity width). Group B represented prepared teeth without any restoration. Group C, Group D, Group E, and Group F were restored with Tetric EvoCeram® incremental-fill (conventional), Beautifil bulk-fill, Filtek posterior bulk-fill, and SonicFill 2 bulk-fill restorative materials, respectively. All samples were finished and polished with an enhanced finishing kit and stored in distilled water for a month before the fracture resistance testing. All the samples were exposed to the axial loading (the speed of crosshead was 1 mm/min) in a computer-controlled universal testing machine (LARYEE, China) via a steel bar (6 mm in diameter) and the maximum applied force in Newton was recorded as the fracture resistance. One-way analysis of variance (SPSS 21) was used to compare the fracture resistance within the groups, and Tukey’s post hoc test was used to determine the difference between the groups. The lowest value of fracture resistance was recorded for Group B, and the highest value was recorded for Group A followed by the values of Group D, Group C, Group F, and Group E. One-way ANOVA revealed a statistically significant difference between the groups ( P < 0.05 ). Nonsignificant difference was found between the premolars restored by bulk-fill and conventional composites. Among the bulk-fill restored specimens, Beautifil restorative demonstrated significantly higher fracture resistance in comparison with the other two bulk-fill restored specimen groups (SonicFill 2 and Filtek). Bulk-fill composite such as Beautifil could be an alternative option to conventional incremental-fill composite for premolar restoration.


2020 ◽  
Vol 8 (D) ◽  
pp. 198-202
Author(s):  
Fariborz Vafaee ◽  
Amirarsalan Hooshyarfard ◽  
Armaghan Shahbazi ◽  
Farnoush Fotovat ◽  
Masoumeh Khoshhal ◽  
...  

BACKGROUND: Metal-ceramics restorations were considered a preferable option for fabrication fixed partial dentures (FPDs) that have an acceptable durability, but they are not able to provide the same beauty as the entire ceramic material. Full-contour zirconia, such as Zolid, does not have problems with chipping of layered zirconia, along with translucency and staining capabilities. AIM: This study aimed to assess the fatigue fracture strength of three-unit implant-supported full-contour zirconia and metal-ceramics posterior FPDs. MATERIALS AND METHODS: In this in vitro study, 24 posterior three-unit implant-supported FPDs were fabricated of full-contour zirconia and metal-ceramics and were cemented on implant abutments. To simulate the oral environment, FPDs were subjected to 10,000 thermal cycles between 5 and 55°C for 30 s and were then transferred to a chewing simulator (100,000 cycles, 50 N, 0.5 Hz). Afterward, fatigue fracture strength was measured using a universal testing machine. Data were analyzed using an independent sample t-test. RESULTS: The obtained results showed that the mean and standard deviation of fatigue fracture strength was higher for the metal-ceramics group (2567.8 ± 689.7 N) compared to those for the full-coverage zirconia group (2108.6 ± 455.2 N). However, the difference was not statistically significant (p ˃ 0.05). CONCLUSIONS: Fracture resistance due to fatigue in the metal-ceramics group was not significantly different from full-coverage zirconia group. Full-coverage zirconia seems promising as a metal-ceramics material for the fabrication of posterior three-unit FPDs.


2014 ◽  
Vol 08 (04) ◽  
pp. 445-449
Author(s):  
Bahman Seraj ◽  
Sara Ehsani ◽  
Shirin Taravati ◽  
Sara Ghadimi ◽  
Mostafa Fatemi ◽  
...  

ABSTRACT Objective: The aim of this study was to comparatively assess the fracture resistance of the cementum-extended and conventional composite fillings with or without intracanal composite posts in severely damaged deciduous incisors. Materials and Methods: This in vitro study was performed on 60 extracted deciduous maxillary incisors that were randomly divided into four groups: Group 1: Composite filling (CF); Group 2: Composite filling with composite posts (CF + CP); Group 3: Composite filling extended 0.5 mm to cementum (ceCF); Group 4: Composite filling extended 0.5 mm to cementum with composite posts (ceCF + CP). The fracture resistance was assessed by exerting a progressively increasing load with a cross-head speed of 0.5 mm/min in a Universal Testing Machine. Statistical Analysis: Data were analyzed by SPSS-18 using one-way analysis of variance at ⍱ < 0.05. Results: The mean fracture resistance (MFR) values of the experimental groups were 410.57 ± 139.44 N, 564.44 ± 92.63 N, 507.5 ± 76.37 N and 601.08 ± 96.04 N. A significant difference was found between the MFR of Groups 1 and 2, Groups 1 and 4 and Groups 3 and 4 (P < 0.05). Conclusion: A superior outcome was achieved by intracanal composite posts in both conventional and cementum-extended composite fillings.


2017 ◽  
Vol 21 (1) ◽  
pp. 44-49
Author(s):  
Sasho Jovanovski ◽  
Julie Popovski ◽  
Alesh Dakskobler ◽  
Ljubo Marion ◽  
Peter Jevnikar

SummaryBackground: Prefabricated zirconia posts can contribute to increasing the fracture resistance of the endodontically treated teeth. Purpose. This in vitro study compared the fracture resistance of endodontically treated central maxillary incisors prepared with 2 mm ferrule length to the ones without ferrule.Material and methods: Twenty-four caries-free maxillary central incisors were divided into 2 groups of 12. In group A circumferential external dentin shoulders were prepared for 2 mm external dentin ferrule length. There was no ferrule preparation in Group B. Zirconia VALLPOST BO-S (Ø 1,6 mm), Ljubljana, Slovenia were used with retention forms in the coronary part. Core build-up was made of pressed ceramics (IPS e.max Press, Ivoclar, Liechtenstein). Crowns were manufactured from the same ceramic material (IPS e.max Press, Ivoclar). After root canal treatment and post space preparation, all posts were cemented with an adhesive resin cement (Multilink Automix, Ivoclar). The specimens were embedded in acrylic resin blocks (ProBase Polymer/Monomer, Ivoclar) and loaded at an angle of 45° to the long axis in an Instron Testing Machine 4301 (Instron Corp., USA) at a crosshead speed of 1 mm/min until fracture. Fracture patterns and loads were recorded. A significance level of p<0.05 was used for all comparisons. Two-way analysis of variance was used for statistical analysis. Failure patterns were analyzed with the optical microscope Stereo Discovery V.8 (Carl Zeiss, Germany) and compared using the chi-square nonparametric test.Results: The mean values (±SD) of fracture loads (N) for the Groups A and B were 664.63N (±49.14) and 519.36N (±71.65) recpectively. Significantly lower failure loads were recorded for the specimens in the group B. Failure patterns within the groups revealed non-catastrophic failure in 70% of the specimens for group A and 85% for group B.Conclusions: Within the limitations of this in vitro study, it can be concluded that zirconia VALLPOST BO-S (Ø 1,6 mm) with press-ceramic cores and crowns, can be used for restoration of endodontically treated teeth. The teeth prepared with 2 mm external dentin ferrule length were found to be more fracture resistant than teeth without ferrule.


Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1234
Author(s):  
António Sérgio Silva ◽  
Aurora Carvalho ◽  
Pedro Barreiros ◽  
Juliana de Sá ◽  
Carlos Aroso ◽  
...  

Thermal and self-curing acrylic resins are frequently and versatilely used in dental medicine since they are biocompatible, have no flavor or odor, have satisfactory thermal qualities and polishing capacity, and are easy and fast. Thus, given their widespread use, their fracture resistance behavior is especially important. In this research work, we comparatively analyzed the fracture resistance capacity of thermo and self-curing acrylic resins in vitro. Materials and Methods: Five prosthesis bases were created for each of the following acrylic resins: Lucitone®, ProBase®, and Megacryl®, which were submitted to different forces through the use of the CS® Dental Testing Machine, usually mobilized in the context of fatigue tests. To this end, a point was defined in the center of the anterior edge of the aforementioned acrylic resin bases, for which the peak tended until a fracture occurred. Thermosetting resins were, on average, more resistant to fracture than self-curable resins, although the difference was not statistically significant. The thermosetting resins of the Lucitone® and Probase® brands demonstrated behavior that was more resistant to fracture than the self-curing homologues, although the difference was not statistically significant. Thermosetting resins tended to be, on average, more resistant to fracture and exhibited the maximum values for impact strength, compressive strength, tensile strength, hardness, and dimensional accuracy than self-curing resins, regardless of brand.


Sign in / Sign up

Export Citation Format

Share Document