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 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 Comparing the Fracture Resistance and Modes of Failure in Different Types of CAD/CAM Zirconia Abutments with Internal Hexagonal Implants: An in Vitro Study

2021 ◽  
Author(s):  
Yu-Tsen Chang ◽  
Yu-Ling Wu ◽  
Hung-Shyong Chen ◽  
Ming-Hsu Tsai ◽  
Chia-Chen Chang ◽  
...  
Keyword(s):  
Fracture Resistance ◽  
Dynamic Test ◽  
In Vitro Study ◽  
Fracture Line ◽  
Horizontal Fracture ◽  
Modes Of Failure ◽  
Significant Difference ◽  
Cad Cam ◽  
Connection Design

Abstract 3 groups of zirconia abutments (n=3) made of different connection design or manufacturers were investigated (All-Zr, ASC-Zr and AM-Zr groups). All-electric dynamic test instrument was used to place static loading on specimen with a crosshead speed set at 1 mm/min. One-way analysis of variance (ANOVA) and post hoc Tukey tests (α=.05) were used for statistical evaluation. The mean fracture resistance was 258.21±68.60 N for All-Zr group, 360.55±29.66 N for ASC-Zr group, and 341.45±25.97 N for AM-Zr group. There was no significant difference in fracture resistance between the 3 groups (1-way ANOVA, P = 0.10). The modes of failure among the 3 types of abutments are different. The All-Zr group showed an oblique fracture line starting from the buccal aspect at the region of the implant platform. While in the ASC-Zr group and the AM-Zr group showed a relatively horizontal fracture line with greater distance from implant platform. The titanium inserts cannot significantly improve the fracture resistance of the zirconia abutment. However, they may alter the modes of failure, allowing buccal fracture surfaces of the zirconia abutments to be placed away from the implant platform, thereby protecting the implant-abutment connection.

scholarly journals Trueness of CAD/CAM digitization with a desktop scanner – an in vitro study

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
G. Joós-Kovács ◽  
B. Vecsei ◽  
Sz. Körmendi ◽  
V. A. Gyarmathy ◽  
J. Borbély ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Reference Data ◽  
In Vitro Study ◽  
Vitro Study ◽  
Computer Assisted ◽  
Surface Information ◽  
Virtual Models ◽  
Cad Cam ◽  
Aided Design

Abstract Background Desktop scanners are devices for digitization of conventional impressions or gypsum casts by indirect Computer-Aided Design/Computer-Assisted Manufacturing (CAD/CAM) in dentistry. The purpose of this in vitro study was: 1, to investigate whether virtual models produced by the extraoral scanner have the same trueness as sectioned casts; and 2, to assess if digitization with an extraoral scanner influences the surface information. Methods A polimethyl-methacrilic acid (PMMA) cast and a reference scanner (TwoCam 3D, SCAN technology A/S, Ringsted, Denmark; field of view 200 mm, resolution 0.1 mm ± 0.025 mm) were used to create the reference data in standard tessellation format (STL). According to the extraoral CAD/CAM digitization steps, impressions, mastercasts, and sectioned casts were made, and STL files were generated with the reference scanner. The pivotal point of the study was to digitalize these sectioned casts with the extraoral scanner (Straumann CARES Scan CS2 Visual 8.0 software, InstitutStraumann AG, Basel, Switzerland) and STL files were exported. Virtual caliper measurements were performed. Absolute deviations were compared using multilevel mixed-effects linear regression. Relative distortions were calculated with mean absolute errors and reference values. Results Differences were observed in measurements of tooth sizes. All four prepared teeth were affected. No relationship was observed in relative deviations. Absolute differences between all the indirect digitization steps considering arch distances were: impressions, − 0.004 mm; mastercasts, 0.136 mm; sectioned casts, − 0.028 mm; and extraoral scanner, − 0.089 mm. Prepared dies on the virtual casts (extraoral scanner) were closer to each other than those on the sectioned gypsum casts. Relative deviation calculations revealed no relationship with the position of the dies in the arch. Conclusion The trueness of the virtual models generated by the extraoral scanner system used in this study was different from the dimensions of the sectioned casts. The digitization of gypsum casts changes both the dimensions of dies and the distances between the dies. The virtual casts had smaller distances than any distances measured at previous steps. Either bigger dies or longer distances did not result in greater distortions. We cannot, however, generalize our results to all scanners available on the market, because they might give different results.

scholarly journals Influence of Intra-Oral Scanner (I.O.S.) on The Marginal Accuracy of CAD/CAM Single Crowns

2019 ◽  
Vol 16 (4) ◽  
pp. 544 ◽  
Author(s):  
Francesco Ferrini ◽  
Gianpaolo Sannino ◽  
Carlo Chiola ◽  
Paolo Capparé ◽  
Giorgio Gastaldi ◽  
...  
Keyword(s):  
Standard Deviation ◽  
In Vitro Study ◽  
Mean Value ◽  
Vitro Study ◽  
Computer Assisted ◽  
Marginal Gap ◽  
Significant Difference ◽  
Cad Cam ◽  
True Definition

The aim of this in vitro study was to compare the quality of digital workflows generated by different scanners (Intra-oral digital scanners (I.O.S.s)) focusing on marginal fit analysis. A customized chrome-cobalt (Cr-Co) implant abutment simulating a maxillary right first molar was fixed in hemi-maxillary stone model and scanned by eight different I.O.S.s: Omnicam® (Denstply Sirona, Verona, Italy) CS3500®, CS3600®, (Carestream Dental, Atlanta, GA, USA), True Definition Scanner® (3M, St. Paul, MN, USA), DWIO® (Dental Wings, Montreal, Quebec, Canada), PlanScan® (Planmeca Oy, Helsinki, Finland), 3D PROGRESS Plus® (MHT, Verona, Italy), TRIOS 3® (3Shape, Copenhagen, Denmark). Nine scans were performed by each tested I.O.S. and 72 copings were designed using a dental computer-assisted-design/computer-assisted-manufacturing (CAD/CAM) software (exocad GmbH, Darmstadt, Germany). According to CAD data, zirconium dioxide (ZrO2) copings were digitally milled (Roland DWX-50, Irvine, CA, USA). Scanning electron microscope (SEM) direct vision allowed for marginal gap measurements in eight points for each specimen. Descriptive analysis was performed using mean, standard deviation, and median, while the Kruskal–Wallis test was performed to determine whether the marginal discrepancies were significantly different between each group (significance level p < 0.05). The overall mean marginal gap value and standard deviation were 53.45 ± 30.52 μm. The minimum mean value (40.04 ± 18.90 μm) was recorded by PlanScan®, then 3D PROGRESS Plus® (40.20 ± 21.91 μm), True Definition Scanner® (40.82 ± 26.19 μm), CS3500® (54.82 ± 28.86 μm) CS3600® (59,67 ± 28.72 μm), Omnicam® (61.57 ± 38.59 μm), DWIO® (62.49 ± 31.54 μm), while the maximum mean value (67.95 ± 30.41 μm) was recorded by TRIOS 3®. The Kruskal–Wallis tests revealed a statistically significant difference (p-value < 0.5) in the mean marginal gaps between copings produced by 3D PROGRESS Plus®, PlanScan, True Definition Scanner, and the other evaluated I.O.S.s. The use of an I.O.S. for digital impressions may be a viable alternative to analog techniques. Although in this in vitro study PlanScan®, 3D PROGRESS Plus® and True Definition Scanner® may have showed the best performances, all I.O.S.s tested could provide clinically encouraging results especially in terms of marginal accuracy, since mean marginal gap values were all within the clinically acceptable threshold of 120 μm.

scholarly journals Accuracy Evaluation of Additively and Subtractively Fabricated Palatal Plate Orthodontic Appliances for Newborns and Infants–An In Vitro Study

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4103
Author(s):  
Maite Aretxabaleta ◽  
Alexey Unkovskiy ◽  
Bernd Koos ◽  
Sebastian Spintzyk ◽  
Alexander B. Xepapadeas
Keyword(s):  
Layer Thickness ◽  
In Vitro Study ◽  
Orthodontic Appliances ◽  
Accuracy Evaluation ◽  
Palatal Plate ◽  
Cad Cam ◽  
Subtractive Manufacturing ◽  
Palatal Stimulation ◽  
Manufacturing Time

Different approaches for digital workflows have already been presented for their use in palatal plates for newborns and infants. However, there is no evidence on the accuracy of CAD/CAM manufactured orthodontic appliances for this kind of application. This study evaluates trueness and precision provided by different CAM technologies and materials for these appliances. Samples of a standard palatal stimulation plate were manufactured using stereolithography (SLA), direct light processing (DLP) and subtractive manufacturing (SM). The effect of material (for SM) and layer thickness (for DLP) were also investigated. Specimens were digitized with a laboratory scanner (D2000, 3Shape) and analyzed with a 3D inspection software (Geomagic Control X, 3D systems). For quantitative analysis, differences between 3D datasets were measured using root mean square (RMS) error values for trueness and precision. For qualitative analysis, color maps were generated to detect locations of deviations within each sample. SM showed higher trueness and precision than AM technologies. Reducing layer thickness in DLP did not significantly increase accuracy, but prolonged manufacturing time. All materials and technologies met the clinically acceptable range and are appropriate for their use. DLP with 100 µm layer thickness showed the highest efficiency, obtaining high trueness and precision within the lowest manufacturing time.

scholarly journals Marginal and Internal Fit of Ceramic Prostheses Fabricated from Different Chairside CAD/CAM Systems: An In Vitro Study

2021 ◽  
Vol 11 (2) ◽  
pp. 857
Author(s):  
Keunbada Son ◽  
Kyu-Bok Lee
Keyword(s):  
Computer Aided Design ◽  
In Vitro Study ◽  
Vitro Study ◽  
Marginal Gap ◽  
Significant Difference ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Internal Fit ◽  
Cam Systems

The purpose of this in vitro study was to evaluate marginal and internal fits of ceramic crowns fabricated with chairside computer-aided design and manufacturing (CAD/CAM) systems. An experimental model based on ISO 12836:2015 was digitally scanned with different intraoral scanners (Omnicam (CEREC), EZIS PO (DDS), and CS3500 (Carestream)). Ceramic crowns were fabricated using the CAD/CAM process recommended by each system (CEREC, EZIS, and Carestream systems; N = 15). The 3-dimensional (3D) marginal and internal fit of each ceramic crown was measured using a 3D inspection software (Geomagic control X). Differences among the systems and various measurements were evaluated using the Kruskal–Wallis test. Statistically significant differences were validated using pairwise comparisons (α = 0.05). Occlusal gaps in the CEREC, EZIS, and Carestream groups were 113.0, 161.3, and 438.2 µm, respectively (p < 0.001). The axial gaps were 83.4, 78.0, and 107.9 µm, respectively. The marginal gaps were 77.8, 99.3, and 60.6 µm, respectively, and the whole gaps were 85.9, 107.3, and 214.0 µm, respectively. Significant differences were observed with the EZIS system compared with the other two systems in terms of the marginal gap sizes. The CEREC system showed no significant differences among the four measured regions. However, the EZIS and Carestream systems did show a statistically significant difference (p < 0.05). All three systems were judged to be capable of fabricating clinically acceptable prostheses, because the marginal gap, which is the most important factor in the marginal fit of prostheses, was recorded to be below 100 µm in all three systems.

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