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Josef Schweiger

Bio: Josef Schweiger is an academic researcher from Ludwig Maximilian University of Munich. The author has contributed to research in topics: Medicine & Ceramic. The author has an hindex of 14, co-authored 64 publications receiving 1474 citations.


Papers
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Journal ArticleDOI
TL;DR: An overview of CAD/CAM-technologies and systems available for dentistry today is given, which enable the access to new, almost defect-free, industrially prefabricated and controlled materials and an improvement in precision and planning, as well as an increase in efficiency.
Abstract: As in many other industries, production stages are increasingly becoming automated in dental technology. As the price of dental laboratory work has become a major factor in treatment planning and therapy, automation could enable more competitive production in high-wage areas like Western Europe and the USA. Advances in computer technology now enable cost-effective production of individual pieces. Dental restorations produced with computer assistance have become more common in recent years. Most dental companies have access to CAD/CAM procedures, either in the dental practice, the dental laboratory or in the form of production centres. The many benefits associated with CAD/CAM generated dental restorations include: the access to new, almost defect-free, industrially prefabricated and controlled materials; an increase in quality and reproducibility and also data storage commensurate with a standardised chain of production; an improvement in precision and planning, as well as an increase in efficiency. As a result of continual developments in computer hardware and software, new methods of production and new treatment concepts are to be expected, which will enable an additional reduction in costs. Dentists, who will be confronted with these techniques in the future, require certain basic knowledge if they are to benefit from these new procedures. This article gives an overview of CAD/CAM-technologies and systems available for dentistry today.

720 citations

Journal ArticleDOI
TL;DR: The new CAD/CAM-fabricated bilayered bilayering restorations (ST) were superior to the present techniques (VT and OT) in terms of fracture load and offer the possibility to produce cost-effective crowns and fixed partial dentures with a potential lower risk of chippings.

256 citations

Journal ArticleDOI
TL;DR: This in vitro study shows that intraoral scanning systems seem to show the same or even higher accuracy than the conventional impression with subsequent indirect digitalization with insufficient data about their accuracy for full-arch scans.
Abstract: Introducing a new approach to evaluate the accuracy of digital impression methods for full-arch scans, avoiding “best-fit alignment.” A lower jaw model with a straight metal bar between the second molars of both quadrants was directly digitized using an intraoral scanner (True Definition, TRD, n = 12) and indirectly digitized (D810, CON, n = 12) after impression and plaster cast. A dataset of the bar from a coordinate measuring machine served as reference (REF). Datasets obtained from test groups were analyzed using inspection software to determine the aberration of the bar length, the linear shift (in X-, Y-, Z-axis) and the angle deviation (α overall, α coronal, α horizontal) caused by the digitalization method. Mann–Whitney U and unpaired two-sample Student’s t test were implemented to detect differences. The level of significance was set at 5 %. Concerning the bar length, no significant differences were found between groups. In view of the linear shift, CON showed significantly higher values than TRD in Y-axis (p = 0.003) and in Z-axis (p = 0.040). Regarding the angle measurement, TRD showed significant smaller values than CON for α overall (p = 0.006) and for α coronal (p = 0.005). This in vitro study shows that intraoral scanning systems seem to show the same or even higher accuracy than the conventional impression with subsequent indirect digitalization. Intraoral scanners have proven excellent accuracy for single teeth or small spans. However, insufficient data is available about their accuracy for full-arch scans. The presented new approach seems to be suitable to precisely analyze differences in the accuracy of different digitalization methods without using best-fit alignment.

96 citations

Journal Article
TL;DR: Different clinical cases with minimally invasive indications for CAD/CAM-fabricated temporary restorations for the pretreatment of complex cases are presented.
Abstract: Complex rehabilitations represent a particular challenge for the restorative team, especially if the vertical dimension of occlusion (VDO) needs to be reconstructed or redefined. The use of provisional acrylic or composite materials allows clinicians to evaluate the treatment objective over a certain period of time and therefore generates a high predictability of the definitive rehabilitation in terms of esthetics and function. CAD/CAM technology enables the use of prefabricated polymer materials, which are fabricated under industrial conditions to form a highly homogeneous structure compared with those of direct fabrication. This increases long-term stability, biocompatibility, and resistance to wear. Furthermore, they offer more suitable CAD/CAM processing characteristics and can be used in thinner thicknesses than ceramic restorative materials. Also, based on the improved long-term stability, the transfer into the definitive restoration can be divided into multiple treatment steps. This article presents different clinical cases with minimally invasive indications for CAD/CAM-fabricated temporary restorations for the pretreatment of complex cases.

89 citations

Journal ArticleDOI
TL;DR: It is shown, based on factual information, to what extent 3D printing can be used in dental laboratories and dental practices at present and which expertise is needed for the digital additive manufacturing of dental restorations.
Abstract: Popular media now often present 3D printing as a widely employed technology for the production of dental prostheses. This article aims to show, based on factual information, to what extent 3D printing can be used in dental laboratories and dental practices at present. It attempts to present a rational evaluation of todays´ applications of 3D printing technology in the context of dental restorations. In addition, the article discusses future perspectives and examines the ongoing viability of traditional dental laboratory services and manufacturing processes. It also shows which expertise is needed for the digital additive manufacturing of dental restorations.

72 citations


Cited by
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Journal ArticleDOI
TL;DR: A comprehensive review of the 4D printing process is presented in this article, which summarizes the practical concepts and related tools that have a prominent role in this field and summarizes the unimportant aspects.

669 citations

Journal ArticleDOI
TL;DR: It is demonstrated that highly polished zirconia yielded lower antagonist wear compared with porcelains, and combined application of silica coating and/or silane coupler, and 10-methacryloyloxydecyl dihydrogen phosphate is currently one of the most reliable bonding systems for zirConia.

529 citations

Journal ArticleDOI
TL;DR: The new reference scanner is capable of measuring the precision and trueness of both digital and conventional complete-arch impressions, and the digital impression is less accurate and shows a different pattern of deviation than the conventional impression.
Abstract: STATEMENT OF PROBLEM: A new approach to both 3-dimensional (3D) trueness and precision is necessary to assess the accuracy of intraoral digital impressions and compare them to conventionally acquired impressions. PURPOSE: The purpose of this in vitro study was to evaluate whether a new reference scanner is capable of measuring conventional and digital intraoral complete-arch impressions for 3D accuracy. MATERIAL AND METHODS: A steel reference dentate model was fabricated and measured with a reference scanner (digital reference model). Conventional impressions were made from the reference model, poured with Type IV dental stone, scanned with the reference scanner, and exported as digital models. Additionally, digital impressions of the reference model were made and the digital models were exported. Precision was measured by superimposing the digital models within each group. Superimposing the digital models on the digital reference model assessed the trueness of each impression method. Statistical significance was assessed with an independent sample t test (α=.05). RESULTS: The reference scanner delivered high accuracy over the entire dental arch with a precision of 1.6 ±0.6 µm and a trueness of 5.3 ±1.1 µm. Conventional impressions showed significantly higher precision (12.5 ±2.5 µm) and trueness values (20.4 ±2.2 µm) with small deviations in the second molar region (P<.001). Digital impressions were significantly less accurate with a precision of 32.4 ±9.6 µm and a trueness of 58.6 ±15.8µm (P<.001). More systematic deviations of the digital models were visible across the entire dental arch. CONCLUSIONS: The new reference scanner is capable of measuring the precision and trueness of both digital and conventional complete-arch impressions. The digital impression is less accurate and shows a different pattern of deviation than the conventional impression.

464 citations

Journal ArticleDOI
TL;DR: Based on the limited number of short-term in vivo studies, zirconia appears to be suitable for the fabrication of single crowns, and fixed partial dentures and implant abutments providing strict protocols during the manufacturing and delivery process are adhered to.
Abstract: Zirconia is unique in its polymorphic crystalline makeup, reported to be sensitive to manufacturing and handling processes, and there is debate about which processing method is least harmful to the final product. Currently, zirconia restorations are manufactured by either soft or hard-milling processes, with the manufacturer of each claiming advantages over the other. Chipping of the veneering porcelain is reported as a common problem and has been labelled as its main clinical setback. The objective of this systematic review is to report on the clinical success of zirconia-based restorations fabricated by both milling processes, in regard to framework fractures and veneering porcelain chipping. A comprehensive review of the literature was completed for in vivo trials on zirconia restorations in MEDLINE and PubMed between 1950 and 2009. A manual hand search of relevant dental journals was also completed. Seventeen clinical trials involving zirconia-based restorations were found, 13 were conducted on fixed partial dentures, two on single crowns and two on zirconia implant abutments, of which 11 were based on soft-milled zirconia and six on hard-milled zirconia. Chipping of the veneering porcelain was a common occurrence, and framework fracture was only observed in soft-milled zirconia. Based on the limited number of short-term in vivo studies, zirconia appears to be suitable for the fabrication of single crowns, and fixed partial dentures and implant abutments providing strict protocols during the manufacturing and delivery process are adhered to. Further long-term prospective studies are necessary to establish the best manufacturing process for zirconia-based restorations.

439 citations

Journal ArticleDOI
TL;DR: The use of zirconia frameworks for long-span fixed partial dentures or for implant-supported restorations is currently under evaluation and further in vivo, long-term clinical studies will be needed to provide scientific evidence for drawing solid guidelines as discussed by the authors.

403 citations