scholarly journals Two Years after Loading Performance of Implant-Supported Overdenture with Metal Bar and Low-Profile Attachments: A Prospective Case Series Multicenter Clinical Study

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Marco Montanari ◽  
Marco Tallarico ◽  
Gabriele Vaccaro ◽  
Emiliano Ferrari ◽  
Roberto Scrascia ◽  
...  
Keyword(s):  
Survival Rate ◽  
Oral Health ◽  
Bone Loss ◽  
Computer Aided Design ◽  
Case Series ◽  
Chromium Alloy ◽  
Technical Complications ◽  
Low Profile ◽  
Computer Aided ◽  
Cad Cam

Background. Prosthetic rehabilitation of patients with atrophic arches can be very challenging. Purpose. The aim of the present prospective multicenter study was to report the two-year preliminary data on clinical and radiographic performance of implant-supported overdentures with a metal bar and low-profile attachments. Material and Methods. A computer-aided design/computer-aided manufacturing (CAD/CAM) titanium bar or a conventional cast metal bar was fabricated according to the anatomy of the ridge, prosthetic contours (teeth setup), and implant position. Three to six threadable OT Equator attachments (Rhein 83, Bologna, Italy) were placed along the implant bar. A cobalt-chromium alloy metal framework was fabricated and fitted onto the metal bar as a counterpart. Prosthetic survival rate, biologic and technical complications, peri-implant bone loss, changes in oral health impact profile index, bleeding on probing, and plaque index were reported. Results. Overall, 177 implants were placed (range three to six) to support 43 metal bars with 170 OT Equators (Rhein 83, range three to six). Eleven metal bars were fabricated using CAD/CAM technology, while the other 32 were conventionally produced using cast technique. All the participants were followed up for at least two years (mean 42.2 months, range 24–88 months) after prosthesis delivery. Two maxillary implants failed in one nonsmoking patient (1.1%). The 2-year prosthesis survival rate was 97.7%. Only three minor technical complications were reported. Two years after loading, the mean marginal bone loss was 0.22 ± 0.09 mm (95% CI: 0.16 to 0.26). Two years after loading, OHIP was 22.3 ± 7.1 (95% CI from 17.4 to 24.6). Compared to the baseline, the difference was statistically significant ( P ≤ 0.001 ). At the two-year follow-up session, successful periodontal parameters were experienced. Conclusions. Implant overdenture supported by a CAD/CAM titanium bar may be a reliable option for the treatment of the edentulous arch over a 2-year period. Oral health-related quality of life significantly improved in all treated participants.

Esthetic Considerations for Reconstructing Implant Emergence Profile Using Titanium and Zirconia Custom Implant Abutments: Fifty Case Series Report

2015 ◽  
Vol 41 (5) ◽  
pp. 554-561 ◽  
Author(s):  
Ahmad Kutkut ◽  
Osama Abu-Hammad ◽  
Richard Mitchell
Keyword(s):  
Computer Aided Design ◽  
Case Series ◽  
Casting Technique ◽  
Custom Implant ◽  
Implant Abutments ◽  
Computer Aided ◽  
Case Series Report ◽  
Cad Cam ◽  
Implant Dentistry ◽  
Implant Restoration

Titanium and zirconia custom implant abutments are now commonly used for esthetic implant dentistry. Custom implant abutments allow the clinician to improve an implant's emergence profile, to customize cervical margins in accordance with the anatomy of the natural root, and to compensate for poor implant angulation. All of these are essential for optimum esthetic outcomes. Computer-aided design/computer-aided machining (CAD/CAM) technology allows the clinician to design custom implant abutment configurations and create natural-looking superstructures that are in harmony with the adjacent dentition and soft tissue. The CAD/CAM technique provides precise fit, reduces the cost of the procedure, and eliminates dimensional inaccuracies inherent in the conventional waxing and casting technique. The aim of this report is to describe a simplified technique for reconstructing emergence profiles during implant restoration using milled titanium and zirconia custom implant abutments. The results of 50 consecutive cases are reported.

Frequency of Technical Complications in Fixed Implant Prosthesis: The Effect of Prosthesis Screw Emergence Correction by Computer-Aided Design/Computer-Aided Manufacturing

2018 ◽  
Vol 44 (6) ◽  
pp. 427-431 ◽  
Author(s):  
Eduardo Anitua ◽  
Carlos Flores ◽  
Laura Piñas ◽  
Mohammad Hamdan Alkhraisat
Keyword(s):  
Computer Aided Design ◽  
Test Group ◽  
Control Group ◽  
Computer Aided Manufacturing ◽  
Screw Channel ◽  
Technical Complications ◽  
Computer Aided ◽  
Cad Cam ◽  
Implant Prosthesis ◽  
Aided Design

Computer-aided design/computer-aided manufacturing (CAD-CAM) technology permits the angular correction of screw emergence into the prosthesis; however, there is lack of controlled clinical studies that assess the frequency of technical complications in angled screw channel restorations. This controlled clinical study was designed to assess technical incidences in angled screw channel restorations. Patients who underwent placement of implant prosthesis between November 2014 and December 2015 were screened. The patients were selected if they received a prosthesis with up to 30° correction of the prosthesis screw emergence and had at least 1 nonangulated prosthesis (screw retained). All prostheses were located completely/partially in the posterior region. The frequency of technical complications was the principal variable. A total of 52 patients with a mean age of 62 ± 10 years participated, with a total of 110 prostheses (55 in the test group and 55 in the control group). A total of 11 technical complications occurred (7 in the test group and 4 in the control group). These differences were not statistically significant. All prostheses in both groups survived the follow-up. The correction of the screw emergence into the prosthesis has not increased the risk of technical complications in CAD-CAM implant prostheses.

Structural Analysis of Product and Computer-Aided Assembly Planning in AssemBL Software Package

2018 ◽  
pp. 11-33
Author(s):  
A. N. Bozhko
Keyword(s):  
Computer Aided Design ◽  
State Of The Art ◽  
Graph Model ◽  
Design System ◽  
Assembly Planning ◽  
Complex Products ◽  
Assembly Sequences ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design

Computer-aided design of assembly processes (Computer aided assembly planning, CAAP) of complex products is an important and urgent problem of state-of-the-art information technologies. Intensive research on CAAP has been underway since the 1980s. Meanwhile, specialized design systems were created to provide synthesis of assembly plans and product decompositions into assembly units. Such systems as ASPE, RAPID, XAP / 1, FLAPS, Archimedes, PRELEIDES, HAP, etc. can be given, as an example. These experimental developments did not get widespread use in industry, since they are based on the models of products with limited adequacy and require an expert’s active involvement in preparing initial information. The design tools for the state-of-the-art full-featured CAD/CAM systems (Siemens NX, Dassault CATIA and PTC Creo Elements / Pro), which are designed to provide CAAP, mainly take into account the geometric constraints that the design imposes on design solutions. These systems often synthesize technologically incorrect assembly sequences in which known technological heuristics are violated, for example orderliness in accuracy, consistency with the system of dimension chains, etc.An AssemBL software application package has been developed for a structured analysis of products and a synthesis of assembly plans and decompositions. The AssemBL uses a hyper-graph model of a product that correctly describes coherent and sequential assembly operations and processes. In terms of the hyper-graph model, an assembly operation is described as shrinkage of edge, an assembly plan is a sequence of shrinkages that converts a hyper-graph into the point, and a decomposition of product into assembly units is a hyper-graph partition into sub-graphs.The AssemBL solves the problem of minimizing the number of direct checks for geometric solvability when assembling complex products. This task is posed as a plus-sum two-person game of bicoloured brushing of an ordered set. In the paradigm of this model, the brushing operation is to check a certain structured fragment for solvability by collision detection methods. A rational brushing strategy minimizes the number of such checks.The package is integrated into the Siemens NX 10.0 computer-aided design system. This solution allowed us to combine specialized AssemBL tools with a developed toolkit of one of the most powerful and popular integrated CAD/CAM /CAE systems.

scholarly journals Fracture Load of Metal, Zirconia and Polyetheretherketone Posterior CAD-CAM Milled Fixed Partial Denture Frameworks

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 959
Author(s):  
Verónica Rodríguez ◽  
Celia Tobar ◽  
Carlos López-Suárez ◽  
Jesús Peláez ◽  
María J. Suárez
Keyword(s):  
Computer Aided Design ◽  
Testing Machine ◽  
Fracture Load ◽  
Fracture Pattern ◽  
Bending Test ◽  
Weibull Statistics ◽  
Promising Alternative ◽  
Computer Aided ◽  
Cad Cam ◽  
Group 2

The aim of this study was to investigate the load to fracture and fracture pattern of prosthetic frameworks for tooth-supported fixed partial dentures (FPDs) fabricated with different subtractive computer-aided design and computer-aided manufacturing (CAD-CAM) materials. Materials and Methods: Thirty standardized specimens with two abutments were fabricated to receive three-unit posterior FDP frameworks with an intermediate pontic. Specimens were randomly divided into three groups (n = 10 each) according to the material: group 1 (MM)—milled metal; group 2 (L)—zirconia; and group 3 (P)—Polyetheretherketone (PEEK). The specimens were thermo-cycled and subjected to a three-point bending test until fracture using a universal testing machine (cross-head speed: 1 mm/min). Axial compressive loads were applied at the central fossa of the pontics. Data analysis was made using one-way analysis of variance, Tamhane post hoc test, and Weibull statistics (α = 0.05). Results: Significant differences were observed among the groups for the fracture load (p < 0.0001). MM frameworks showed the highest fracture load values. The PEEK group registered higher fracture load values than zirconia samples. The Weibull statistics corroborated these results. The fracture pattern was different among the groups. Conclusions: Milled metal provided the highest fracture load values, followed by PEEK, and zirconia. However, all tested groups demonstrated clinically acceptable fracture load values higher than 1000 N. PEEK might be considered a promising alternative for posterior FPDs.

scholarly journals Evaluation of the Feasibility of NaCaPO4-Blended Zirconia as a New CAD/CAM Material for Dental Restoration

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3819
Author(s):  
Ting-Hsun Lan ◽  
Yu-Feng Chen ◽  
Yen-Yun Wang ◽  
Mitch M. C. Chou
Keyword(s):  
Computer Aided Design ◽  
Optical Microscope ◽  
Dental Restoration ◽  
Numerical Control ◽  
Test Results ◽  
Cnc Machine ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design ◽  
Better Than

The computer-aided design/computer-aided manufacturing (CAD/CAM) fabrication technique has become one of the hottest topics in the dental field. This technology can be applied to fixed partial dentures, removable dentures, and implant prostheses. This study aimed to evaluate the feasibility of NaCaPO4-blended zirconia as a new CAD/CAM material. Eleven different proportional samples of zirconia and NaCaPO4 (xZyN) were prepared and characterized by X-ray diffractometry (XRD) and Vickers microhardness, and the milling property of these new samples was tested via a digital optical microscope. After calcination at 950 °C for 4 h, XRD results showed that the intensity of tetragonal ZrO2 gradually decreased with an increase in the content of NaCaPO4. Furthermore, with the increase in NaCaPO4 content, the sintering became more obvious, which improved the densification of the sintered body and reduced its porosity. Specimens went through milling by a computer numerical control (CNC) machine, and the marginal integrity revealed that being sintered at 1350 °C was better than being sintered at 950 °C. Moreover, 7Z3N showed better marginal fit than that of 6Z4N among thirty-six samples when sintered at 1350 °C (p < 0.05). The milling test results revealed that 7Z3N could be a new CAD/CAM material for dental restoration use in the future.

scholarly journals Characterisation of the Filler Fraction in CAD/CAM Resin-Based Composites

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1986
Author(s):  
Andreas Koenig ◽  
Julius Schmidtke ◽  
Leonie Schmohl ◽  
Sibylle Schneider-Feyrer ◽  
Martin Rosentritt ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Point Of View ◽  
Specific Information ◽  
Dental Resin ◽  
X Ray ◽  
Computer Aided ◽  
Cad Cam ◽  
Filler Fraction ◽  
The Individual ◽  
Aided Design

The performance of dental resin-based composites (RBCs) heavily depends on the characteristic properties of the individual filler fraction. As specific information regarding the properties of the filler fraction is often missing, the current study aims to characterize the filler fractions of several contemporary computer-aided design/computer-aided manufacturing (CAD/CAM) RBCs from a material science point of view. The filler fractions of seven commercially available CAD/CAM RBCs featuring different translucency variants were analysed using Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS), Micro-X-ray Computed Tomography (µXCT), Thermogravimetric Analysis (TG) and X-ray Diffractometry (XRD). All CAD/CAM RBCs investigated included midifill hybrid type filler fractions, and the size of the individual particles was clearly larger than the individual specifications of the manufacturer. The fillers in Shofu Block HC featured a sphericity of ≈0.8, while it was <0.7 in all other RBCs. All RBCs featured only X-ray amorphous phases. However, in Lava Ultimate, zircon crystals with low crystallinity were detected. In some CAD/CAM RBCs, inhomogeneities (X-ray opaque fillers or pores) with a size <80 µm were identified, but the effects were minor in relation to the total volume (<0.01 vol.%). The characteristic parameters of the filler fraction in RBCs are essential for the interpretation of the individual material’s mechanical and optical properties.

scholarly journals Influence of Sequential CAD/CAM Milling on the Fitting Accuracy of Titanium Three-Unit Fixed Dental Prostheses

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1401
Author(s):  
Doo-Bin Song ◽  
Man-So Han ◽  
Si-Chul Kim ◽  
Junyong Ahn ◽  
Yong-Woon Im ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Computer Aided Design ◽  
Dental Prostheses ◽  
Computer Aided ◽  
Cad Cam ◽  
Fixed Dental Prostheses ◽  
Gap Data ◽  
Aided Design ◽  
Fitting Accuracy

This study investigated the fitting accuracy of titanium alloy fixed dental prostheses (FDP) after sequential CAD/CAM (Computer Aided Design/Computer Aided Manufacturing) fabrication. A three-unit FDP model connecting mandibular second premolars and molars was prepared and scanned to fabricate titanium FDPs by CAD/CAM milling. A total of six FDPs were sequentially milled in one titanium alloy disk using a new set of burs every time (n = 4). The fitting accuracy of FDPs was mesiodistally evaluated by a silicone replica technique and the measurement was triplicated at four different locations: MO (marginal opening), MG (marginal gap), AG (axial gap), and OG (occlusal gap). Data were statistically analyzed using ANOVA and Tukey’s HSD test. The fitting accuracy of PMMA (polymethyl methacrylate) FDPs milled using the worn or new bur were evaluated by the same procedure (n = 6). The mean dimensions of titanium FDP for all measuring positions, except for AG, were significantly increased from the third milling. However, no difference was noted between the first FDP and the second FDP milled with the same set of burs. Severe edge chippings were observed in all milling burs. Detrimental effects of the worn burs on the fitting accuracy were demonstrated in the CAD/CAM-milled PMMA FDP. The results recommend proper changing frequency of cutting burs to achieve the quality of fit and predictable outcomes for dental CAD/CAM prostheses.

Surface Roughness of Two CAD/CAM Restorative Materials as Affected by Chewing Simulation v1

2022 ◽  
Author(s):  
eaeldwakhly not provided
Keyword(s):  
Surface Roughness ◽  
Computer Aided Design ◽  
Surface Characteristics ◽  
Ceramic Materials ◽  
Study Groups ◽  
Significance Level ◽  
Chewing Simulation ◽  
Computer Aided ◽  
Cad Cam ◽  
The Individual

This study was conducted to assess the surface characteristics in terms of roughness of two CAD/CAM (Computer-Aided-Design/Computer-Aided Manufacturing)restorative material spre and post chewing simulation exposure. Methods: Specimens were prepared from two CAD/CAM ceramic materials: Cerec Blocs C and IPS e-max ZirCAD. A total of 10 disks were prepared for each study group. 3D optical noncontact surface profiler was used to test the surface roughness (ContourGT, Bruker, Campbell, CA, USA). A silicone mold was used to fix the individual samples using a self-curing resin. Surface roughness (SR) was examined pre and post exposure to chewing simulation. 480,000 simulated chewing cycles were conducted to mimic roughly two years of intraoral clinical service. The results data was first tested for normality and equal variance (Levene’s test >0.05) then examined with paired and independent sample t-test at a significance level of (p < 0.05). Results:The two CAD-CAM materials tested exhibited increased surface roughness from baseline. The highest mean surface roughness was observed in Cerec blocs C group after chewing simulation (2.34 µm± 0.62 µm). Whereas the lowest surface roughness was observed in IPS e.max ZirCAD group before chewing simulation (0.42 µm± 0.16 µm). Both study groups exhibited significantly different surface roughness values (p< 0.05). There was a statistically higher surface roughness values after the chewing simulation in Cerec blocs C when compared to IPS e.max ZirCAD groups (p = 0.000).Conclusion:Even though both tested CAD/CAM materials differ in recorded surface roughness values, results were within clinically accepted values.

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