Comparison of digital and silicone impressions for single-tooth implants and two- and three-unit implants for a free-end edentulous saddle

Abstract Background The use of intraoral scanners (IOS) has facilitated the use of digital workflows for the fabrication of implant-supported prostheses not only for single missing teeth, but also for multiple missing teeth. However, the clinical application of IOS and computer-aided design/manufacturing (CAD/CAM) in implant-supported prosthodontics remains unclear. This study aimed to compare the accuracy of digital and silicone impressions for single-tooth implants for bounded edentulous spaces and two-unit and three-unit implant-supported fixed dental prostheses for free-end edentulous spaces. Methods This study enrolled 30 patients (n = 10 for each of the three groups) with an average age of 61.9 years. Conventional silicone-based and digital IOS-based impressions were made for all patients, and the implant superstructures were fabricated. We measured the scan-body misfit and compared the accuracy of the impressions for single-unit, two-unit, and three-unit implant prostheses with a bounded edentulous space by superimposing the standard triangulated language (STL) data obtained from IOS over the STL data of the plaster model used for final prosthesis fabrication. The scan bodies of the superimposed single-molar implant, two-unit implant prosthesis without teeth on the mesial side, two-unit implant prosthesis without teeth on the distal side, three-unit implant prosthesis without teeth on the mesial side, and three-unit implant prosthesis without teeth on the distal side were designated as A, B1, B2, C1, and C2, respectively. The misfit for each scan body was calculated and the accuracies were compared using the Tukey–Kramer method. Results The average scan-body misfit for conditions A, B1, B2, C1, and C2 was 40.5 ± 18.9, 45.4 ± 13.4, 56.5 ± 9.6, 50.7 ± 14.9, and 80.3 ± 12.4 μm, respectively. Significant differences were observed between the accuracies of A and B2, A and C2, and C1 and C2 (P < 0.001). Conclusions IOS and CAD/CAM can find clinical applications for implant-supported prostheses of up to three units for a bounded edentulous saddle. The use of IOS could render implant treatment easier, benefiting both the surgeons and patients. Prosthesis maladjustment may lead to peri-implantitis and prosthetic fracture. Therefore, further validation of the accuracy of IOS impressions is required in patients with multiple missing teeth in long-span implant prostheses.

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

Materials ◽

10.3390/ma14061401 ◽

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.

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Strategic Use of CAD-CAM Interim Restoration for the Recovery of the Vertical Dimension of Occlusion in the Posterior Partially Edentulous Jaw

Applied Sciences ◽

10.3390/app10217735 ◽

2020 ◽

Vol 10 (21) ◽

pp. 7735

Author(s):

Hai Yen Mai ◽

Jae-Min Seo ◽

Jae-Kwang Jung ◽

Du-Hyeong Lee

Keyword(s):

Case Report ◽

Computer Aided Design ◽

Vertical Dimension ◽

Posterior Region ◽

Occlusal Contact ◽

Dental Prostheses ◽

Computer Aided ◽

Cad Cam ◽

Fixed Dental Prostheses ◽

Aided Design

Occlusal contact loss occasionally occurs following the placement of implant-supported fixed dental prostheses in the posterior region. This complication is caused by the change in the vertical dimension of occlusion after the recovery of mastication. The change is probably related to the prosthesis sinking phenomenon and previous mandibular dislocation. The use of interim prostheses could help re-establish the vertical dimension of occlusion. The definitive prostheses can then be accurately fabricated using digital techniques in the newly established vertical dimension. In this case report, we introduce a protocol incorporating a computer-aided design and computer-aided manufacturing (CAD-CAM) interim prosthesis and digital techniques to minimize the occurrence of unexpected initial occlusal changes in the prosthetic treatment of implant-supported prostheses in the posterior region.

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Tooth-Colored CAD/CAM Materials for Application in 3-Unit Fixed Dental Prostheses in the Molar Area: An Illustrated Clinical Comparison

Materials ◽

10.3390/ma13245588 ◽

2020 ◽

Vol 13 (24) ◽

pp. 5588

Author(s):

Angelika Rauch ◽

Sebastian Hahnel ◽

Elena Günther ◽

Wolfgang Bidmon ◽

Oliver Schierz

Keyword(s):

Computer Aided Design ◽

Milling Time ◽

Composite Resin ◽

Dental Prostheses ◽

The Us ◽

Computer Aided ◽

Cad Cam ◽

Indirect Composite ◽

Fixed Dental Prostheses ◽

Aided Design

The aim of this study was to compare the clinical properties of tooth-colored computer-aided design/computer-aided manufacturing (CAD/CAM) materials for the fabrication of a 3-unit fixed dental prostheses (FDPs) in the same clinical scenario. A 53-year-old female patient was supplied with a 3-unit FDP to replace a second premolar in the upper jaw. Restorations were fabricated from 3 mol%, 4 mol%, and 5 mol% yttrium oxide zirconia, zirconia with translucency gradient, indirect composite resin, polyetheretherketone (PEEK), and polyetherketoneketone (PEKK). Milling time, weight, and radiopacity were investigated. Esthetics were examined following the US Public Health Service criteria (USPHS). The milling time for zirconia was twice as high as for the indirect composite resin, PEEK, or PEKK. The latter materials had a weight of 2 g each, while zirconia restorations yielded 5 g. Zirconia presented intense radiopacity. PEEK and PEKK required veneering and an opaquer was applied to the PEKK framework. All FDPs showed acceptable esthetics. PEEK and PEKK restorations were featured by a grayish shimmering. A variety of CAD/CAM materials are available to fabricate 3-unit FDPs with esthetically acceptable results. In the esthetic zone, PEEK and PEKK require veneering and an opaquer might be applied. Milling time, weight, and radiopacity were relatively high for zirconia FDPs.

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Effect of Fabrication Method on Fracture Strength of Provisional Implant-Supported Fixed Dental Prostheses

Prosthesis ◽

10.3390/prosthesis2040030 ◽

2020 ◽

Vol 2 (4) ◽

pp. 325-332

Author(s):

Kelly M. Suralik ◽

Jie Sun ◽

Chia-Yu Chen ◽

Sang J. Lee

Keyword(s):

Computer Aided Design ◽

Fracture Force ◽

Fixed Dental Prosthesis ◽

Computer Aided ◽

Cad Cam ◽

3D Printers ◽

Fixed Dental Prostheses ◽

3D Printed ◽

Aided Design ◽

Post Hoc

There has been an increase in utilizing 3D printers in dental restorations. The purpose of the study is to compare mechanical properties of 3D-printed prostheses to those of self-cured and/or computer-aided design-computer-aided manufacturing (CAD-CAM) restorations. A metal master typodont was prepared for the mandibular left sextant with implant analogs embedded at the first premolar and first molar positions with a missing second premolar. Three-unit provisional fixed dental prosthesis (FDP) was designed utilizing the 3Shape tooth library and forty-five uniform specimens were fabricated with different materials: self-cured poly(methyl methacrylate) (PMMA) (N = 15), milled PMMA CAD-CAM blocks (N = 15) and 3D-printed resin (N = 15). All specimens were tested using an Instron machine at a crosshead speed of 0.5 mm/min by an axial load on the occlusal surface of the second premolar pontic site. Statistical analysis was completed with Shapiro-Wilk, ANOVA and Tukey post-hoc tests. Mean fracture force was 300.61 N, 294.64 N and 408.49 N for self-cured PMMA, milled PMMA and 3D-printed resin, respectively. Mean force at FDP fracture of 3D-printed resin was significantly greater than the mean fracture force of either self-cured (p = 0.016, 95% CI [17.86, 197.91]) or milled (p = 0.010, 95% CI [23.83, 203.88]) PMMA.

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The Evolution of Dental Materials for Hybrid Prosthesis

The Open Dentistry Journal ◽

10.2174/1874210601408010085 ◽

2014 ◽

Vol 8 (1) ◽

pp. 85-94 ◽

Cited By ~ 7

Author(s):

Jorge Gonzalez

Keyword(s):

Computer Aided Design ◽

Adult Population ◽

Dental Materials ◽

Missing Teeth ◽

Dental Restorations ◽

Computer Aided ◽

Cad Cam ◽

Hybrid Prosthesis ◽

Aided Design ◽

Older Adult Population

Since the immemorial, the replacement of missing teeth has been a medical and cosmetic necessity for human kind. Nowadays, middle-aged population groups have experienced improved oral health, as compared to previous generations, and the percentage of edentulous adults can be expected to further decline. However, with the continued increase in the number of older adult population, it is anticipated that the need for some form of full-mouth restoration might increase from 53.8 million in 1991 to 61 million in 2020 [1]. Denture prosthetics has undergone many development stages since the first dentures were fabricated. The introduction of computer-aided design/computer aided manufacturing (CAD/CAM) has resulted in a more accurate manufacturing of prosthetic frameworks, greater accuracy of dental restorations, and in particular, implant supported prosthesis.

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Bending Fracture of Different Zirconia-Based Bioceramics for Dental Applications: A Comparative Study

Materials ◽

10.3390/ma14226887 ◽

2021 ◽

Vol 14 (22) ◽

pp. 6887

Author(s):

Peter Fischer ◽

Horia Mihail Barbu ◽

Caroline Adela Ingrid Fischer ◽

Mihaela Pantea ◽

Florin Baciu ◽

...

Keyword(s):

Grain Size ◽

Computer Aided Design ◽

Sem Analysis ◽

Structural Defects ◽

Dental Prostheses ◽

Computer Aided ◽

Cad Cam ◽

Fixed Dental Prostheses ◽

Aided Design ◽

Dental Applications

The fabrication of fixed dental prostheses using aesthetic materials has become routine in today’s dentistry. In the present study, three-unit full zirconia fixed prosthetic restorations obtained by computer-aided design/computer-aided manufacturing (CAD/CAM) technology were tested by bending trials. The prostheses were intended to replace the first mandibular left molar and were manufactured from four different types of zirconia bioceramics (KatanaTM Zirconia HTML and KatanaTM Zirconia STML/Kuraray Noritake Dental Inc.; NOVAZir® Fusion float® ml/NOVADENT/Dentaltechnik; and 3D PRO Zirconia/Bloomden Bioceramics). In total, sixteen samples were manufactured—four samples per zirconia material. Additionally, the morphology, grain size area distribution, and elemental composition were analyzed in parallelepiped samples made from the selected types of zirconia in three different areas, noted as the upper, middle, and lower areas. The scanning electron microscope (SEM) analysis highlighted that the grain size area varies with respect to the researched area and the type of material. Defects such as microcracks and pores were also noted to a smaller extent. In terms of grain size area, it was observed that most of the particles in all samples were under 0.5 μm2, while the chemical composition of the investigated materials did not vary significantly. The results obtained after performing the bending tests showed that a zirconia material with fewer structural defects and an increased percentage of grain size area under 0.5 µm2, ranging from ~44% in the upper area to ~74% in the lower area, exhibited enhanced mechanical behavior. Overall, the resulting values of all investigated parameters confirm that the tested materials are suitable for clinical use.

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

Journal of Oral Implantology ◽

10.1563/aaid-joi-d-17-00229 ◽

2018 ◽

Vol 44 (6) ◽

pp. 427-431 ◽

Cited By ~ 2

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.

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

Mechanical Engineering and Computer Science ◽

10.24108/0818.0001424 ◽

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.

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

Materials ◽

10.3390/ma14143819 ◽

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.

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

Materials ◽

10.3390/ma14081986 ◽

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.

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