scholarly journals Fracture Resistance of CAD/CAM Versus Traditional Interim Fixed Dental Prostheses

2018 ◽  
Vol 55 (3) ◽  
pp. 361-363
Author(s):  
Daniel Alexandru Pop ◽  
R. Malaescu ◽  
Liviu Marsavina ◽  
Tiberiu Hosszu ◽  
Raul Rotar ◽  
...  
Keyword(s):  
Testing Machine ◽  
In Vitro Study ◽  
Maximum Load ◽  
Fracture Load ◽  
Digital Design ◽  
Computer Assisted ◽  
Dental Prostheses ◽  
Cad Cam ◽  
Fixed Dental Prostheses

The aim of this in vitro study is to compare the load-to-fracture performance of polymethyl methacrylates (PMMA) provisional restorations manufactured with a traditional laboratory technique in comparison to a computer-assisted design and computer-assisted manufacturing (CAD-CAM) technique. Five interim three-unit fixed dental prostheses were fabricated with the conventional indirect technique, on a standard typodont. The same model was scanned with an intraoral scanner and the digital design of identical fixed dental prostheses was made. Then other five interim three-unit fixed dental prostheses were milled from PMMA CAD/CAM blocks with an in office milling machine. All specimens were tested for flexural strength in a universal testing machine, and the maximum load to fracture was measured. For the conventional provisional restorations, the load to fracture was 121.16 � 24.6, in comparison to CAD/CAM interim restorations, for which the load to fracture was 728.88 � 228.7. Within the limitations of this study, one can conclude that CAD/CAM provisional restorations present a higher fracture load than the conventional manufactured interim restorations.

scholarly journals CAD/CAM Resin-Based Composites for Use in Long-Term Temporary Fixed Dental Prostheses

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3469
Author(s):  
Franziska Hensel ◽  
Andreas Koenig ◽  
Hans-Martin Doerfler ◽  
Florian Fuchs ◽  
Martin Rosentritt ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Chewing Simulation ◽  
Long Term Stability ◽  
Dental Prostheses ◽  
Alternative Materials ◽  
Cad Cam ◽  
Fixed Dental Prostheses ◽  
Additional Image

The aim of this in vitro study was to analyse the performance of CAD/CAM resin-based composites for the fabrication of long-term temporary fixed dental prostheses (FDP) and to compare it to other commercially available alternative materials regarding its long-term stability. Four CAD/CAM materials [Structur CAD (SC), VITA CAD-Temp (CT), Grandio disc (GD), and Lava Esthetic (LE)] and two direct RBCs [(Structur 3 (S3) and LuxaCrown (LC)] were used to fabricate three-unit FDPs. 10/20 FDPs were subjected to thermal cycling and mechanical loading by chewing simulation and 10/20 FDPs were stored in distilled water. Two FDPs of each material were forwarded to additional image diagnostics prior and after chewing simulation. Fracture loads were measured and data were statistically analysed. SC is suitable for use as a long-term temporary (two years) three-unit FDP. In comparison to CT, SC featured significantly higher breaking forces (SC > 800 N; CT < 600 N) and the surface wear of the antagonists was (significantly) lower and the abrasion of the FDP was similar. The high breaking forces (1100–1327 N) of GD and the small difference compared to LE regarding flexural strength showed that the material might be used for the fabrication of three-unit FDPs. With the exception of S3, all analysed direct or indirect materials are suitable for the fabrication of temporary FDPs.

scholarly journals Comparing the Maximum Load Capacity and Modes of Failure of Original Equipment Manufactured and Aftermarket Titanium Abutments in Internal Hexagonal Implants

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 556 ◽  
Author(s):  
Yutsen Chang ◽  
Yuling Wu ◽  
Hungshyong Chen ◽  
Minghsu Tsai ◽  
Chiachen Chang ◽  
...  
Keyword(s):  
Load Capacity ◽  
Dynamic Test ◽  
In Vitro Study ◽  
Maximum Load ◽  
Computer Assisted ◽  
Modes Of Failure ◽  
Computer Assisted Design ◽  
Cad Cam ◽  
Original Equipment Manufacturers

The purpose of this in vitro study is to compare the maximum load capacity and modes of failure under static loading in three types of titanium abutments (n = 3) with different processes or manufacturers. The Pre-Ti group consists of prefabricated titanium abutments from original equipment manufacturers (OEM), the CAD-Ti group consists of OEM titanium abutments fabricated with computer-assisted design/manufacturing (CAD/CAM) technique, and the AM-Ti group is CAD/CAM titanium abutment made by aftermarket manufacturers. A full zirconia crown was fabricated and cemented to each abutment. An all-electric dynamic test instrument was used to place loading on the zirconia crown with a crosshead speed set at 1 mm/min. The mean maximum load capacity of both OEM titanium abutments was significantly higher than the aftermarket titanium abutments. All these three types of implant–abutment complexes exhibited similar modes of failure, which included deformation of the abutment and implant, fracture of the abutment and retentive screw.

scholarly journals Fracture Load of CAD/CAM Fabricated Cantilever Implant-Supported Zirconia Framework: An In Vitro Study

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2259
Author(s):  
Ibraheem F. Alshiddi ◽  
Syed Rashid Habib ◽  
Muhammad Sohail Zafar ◽  
Salwa Bajunaid ◽  
Nawaf Labban ◽  
...  
Keyword(s):  
Testing Machine ◽  
In Vitro Study ◽  
Milling Process ◽  
Fracture Load ◽  
Vitro Study ◽  
Cross Sectional ◽  
Cantilever Length ◽  
Computer Aided ◽  
Cad Cam

The fracture resistance of computer-aided designing and computer-aided manufacturing CAD/CAM fabricated implant-supported cantilever zirconia frameworks (ISCZFs) is affected by the size/dimension and the micro cracks produced from diamond burs during the milling process. The present in vitro study investigated the fracture load for different cross-sectional dimensions of connector sites of implant-supported cantilever zirconia frameworks (ISCZFs) with different cantilever lengths (load point). A total of 48 ISCZFs (Cercon, Degudent; Dentsply, Deutschland, Germany) were fabricated by CAD/CAM and divided into four groups based on cantilever length and reinforcement of distal-abutment: Group A: 9 mm cantilever; Group B: 9 mm cantilever with reinforced distal-abutment; Group C: 12 mm cantilever; Group D: 12 mm cantilever with reinforced distal-abutment (n = 12). The ISCZFs were loaded using a universal testing machine for recording the fracture load. Descriptive statistics, ANOVA, and Tukey’s test were used for the statistical analysis (p < 0.05). Significant variations were found between the fracture loads of the four ISCZFs (p = 0.000); Group-C and B were found with the weakest and the strongest distal cantilever frameworks with fracture load of 670.39 ± 130.96 N and 1137.86 ± 127.85 N, respectively. The mean difference of the fracture load between groups A (810.49 + 137.579 N) and B (1137.86 ± 127.85 N) and between C (670.39 ± 130.96 N) and D (914.58 + 149.635 N) was statistically significant (p = 0.000). Significant variations in the fracture load between the ISCZFs with different cantilever lengths and thicknesses of the distal abutments were found. Increasing the thickness of the distal abutment only by 0.5 mm reinforces the distal abutments by significantly increasing the fracture load of the ISCZFs. Therefore, an increase in the thickness of the distal abutments is recommended in patients seeking implant-supported distal cantilever fixed prostheses.

Comparative Biomechanical Characteristics of Modified Side-to-Side Repair and Modified Pulvertaft Weaving Repair – In vitro Study

2019 ◽  
Vol 24 (01) ◽  
pp. 76-82
Author(s):  
Sudhir Kannan ◽  
Arijit I. Ghosh ◽  
Joseph J. Dias ◽  
Harvinder Pal Singh
Keyword(s):  
Tensile Stress ◽  
Testing Machine ◽  
In Vitro Study ◽  
Early Mobilization ◽  
Maximum Load ◽  
Mode Of Failure ◽  
Mechanical Basis ◽  
Anchor Points ◽  
Biomechanical Strength

Background: Strong surgical repair is the mechanical basis of early mobilization and prerequisite for biological healing following tendon grafting. Side to side and pulvertaft repairs were developed to meets these demands. However, these techniques have later been modified to improve the strength of repair but their characteristics have not been compared. Methods: We compared biomechanical strength of the modified side-to-side (SS) repair with the modified Pulvertaft (PT) repair technique in turkey tendons keeping overlap length, anchor points, type of suture, suture throw and amount of suture similar. Two investigators performed 34 repairs during one summer month to test the tensile strength of the repair using mechanical strength testing machine. Variables measured were maximum load, load to first failure, modulus, load at break, mode of failure, site of failure, tensile strain, tensile stress. The statistical comparison was carried by Levene’s test and T test for means. Results: The mean maximum load for modified SS repair was 50.3 (SD 13.7) N and modified PT repair was 46.9 (SD 16.4) N. The tensile stress at maximum load for SS and modified PT repair was 4.7 (SD 4) MPa and 4.2 (SD 3) MPa respectively. The suture cut through was the commonest mode of failure. Conclusions: We found no statistical difference between 2 repairs in load at which they started failing (p = 0.16), and maximum load repairs could withstand (p = 0.35). Our study uniquely compares two techniques under standard conditions, and contrary to existing evidence found no difference. However, in our opinion the number of anchor points may have a greater impact than number of weaves on the strength.

scholarly journals Does Printing Orientation Matter? In-Vitro Fracture Strength of Temporary Fixed Dental Prostheses after a 1-Year Simulation in the Artificial Mouth

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 259
Author(s):  
Julian Nold ◽  
Christian Wesemann ◽  
Laura Rieg ◽  
Lara Binder ◽  
Siegbert Witkowski ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Fracture Strength ◽  
Computer Aided Design ◽  
In Vitro Study ◽  
Bending Test ◽  
Dental Prostheses ◽  
Computer Aided ◽  
Subtractive Manufacturing ◽  
Fixed Dental Prostheses

Computer-aided design and computer-aided manufacturing (CAD–CAM) enable subtractive or additive fabrication of temporary fixed dental prostheses (FDPs). The present in-vitro study aimed to compare the fracture resistance of both milled and additive manufactured three-unit FDPs and bar-shaped, ISO-conform specimens. Polymethylmethacrylate was used for subtractive manufacturing and a light-curing resin for additive manufacturing. Three (bars) and four (FDPs) different printing orientations were evaluated. All bars (n = 32) were subjected to a three-point bending test after 24 h of water storage. Half of the 80 FDPs were dynamically loaded (250,000 cycles, 98 N) with simultaneous hydrothermal cycling. Non-aged (n = 40) and surviving FDPs (n = 11) were subjected to static loading until fracture. Regarding the bar-shaped specimens, the milled group showed the highest flexural strength (114 ± 10 MPa, p = 0.001), followed by the vertically printed group (97 ± 10 MPa, p < 0.007). Subtractive manufactured FDPs revealed the highest fracture strength (1060 ± 89 N) with all specimens surviving dynamic loading. During artificial aging, 29 of 32 printed specimens failed. The present findings indicate that both printing orientation and aging affect the strength of additive manufactured specimens. The used resin and settings cannot be recommended for additive manufacturing of long-term temporary three-unit FDPs.

scholarly journals Mathematical validation of measurement of root fracture resistance: an in vitro study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Rafat Bagheri ◽  
Abbas Abbaszadegan ◽  
Mohammad R. Nabavizadeh ◽  
Maryam Ferooz ◽  
Peter Parashos
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Maximum Load ◽  
Control Groups ◽  
Root Fracture ◽  
Root Canals ◽  
Gutta Percha ◽  
Root Fracture Resistance

Abstract Background The aim of this study was to develop a mathematically valid method of assessing fracture resistance of roots. The model developed used mesial roots of lower molars instrumented using stainless steel hand files (SS) and two rotary nickel-titanium (NiTi) systems. Methods Eighty human lower molars were selected and randomly divided into four groups (n = 20). After instrumentation, the root canals were obturated using thermoplasticized gutta percha. The roots were covered with a simulated periodontal ligament and mounted vertically in autopolymerizing acrylic in PVC tubes. Using a universal testing machine, the force to fracture (N) was applied and the maximum load (FL) was recorded. Remaining dentine volume was calculated and the fracture resistance (FR) was recorded. The data were analyzed using SPSS version 22 with P < .05. Results There were no significant differences among the instrumentation methods for FL but in FR the roots instrumented using rotary NiTi showed significantly lower values than control groups and SS files (P < 0.001). Conclusions Considering the effect of root length, volume of the root, and volume of the instrumented canal as well as the maximum failure load may be a more objective method of reporting fracture resistance of roots.

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