A prospective clinical cohort study analyzing single-unit implant crowns after three years of loading: introduction of a novel Functional Implant Prosthodontic Score (FIPS)

Objectives The aim of this prospective clinical cohort study was to validate implant crowns with a novel Functional Implant Prosthodontic Score (FIPS). Material and methods Twenty patients were restored with cement-retained crowns on soft tissue level implants (Institut Straumann AG, Basel, Switzerland) in posterior sites and annually followed-up for 3 years. FIPS was applied for the objective outcome assessment including clinical and radiographic examinations. Five variables were defined for evaluation, resulting in a maximum score of 10 per implant restoration. The patients' level of satisfaction was recorded and correlated with FIPS. Results All implants and connected crowns revealed survival rates of 100% without any biological or technical complications after three years of loading. The mean total FIPS score was 7.8 ± 1.5, ranging from 6 to 10. The variable “bone” revealed the highest scores (2 ± 0; range: 2–2), followed by “occlusion” (1.9 ± 0.1; range: 1–2). Mean scores for “design” (1.2 ± 0.6; range: 0–2), “mucosa” (1.3 ± 0.7; range: 0–2), and “interproximal” (1.4 ± 0.4; range: 1–2) were more challenging to satisfy. The patients expressed a high level of functional satisfaction (84.1 ± 9.5; range: 68–100). A significant correlation was found between FIPS and the subjective patients' perception with a coefficient of 0.88 (P < 0.0001). Conclusions The findings of the clinical trial indicated the potential of FIPS as an objective and reliable instrument in assessing implant success. FIPS can be considered as a supportive tool to validate a satisfactory outcome as perceived by patients, to identify possible failure risks, and to compare follow-up observations

Die Fernröntgenfrontalaufnahme:Analyse von Indikation, Häufigkeit und Relation in der kieferorthopädischen Röntgendiagnostik für den Zeitraum von 1993 bis 2001

Die Studie setzt sich aus einer Literaturübersicht zur Fernröntgenfrontalaufnahme und einer statistischen Auswertung zur kieferorthopädischen Röntgendiagnostik zusammen. Orthopantomogramme und Fernröntgenseitenaufnahmen sind die häufigsten Aufnahmen in der Kieferorthopädie und werden in der Literatur als "Gold-Standard" bezeichnet. Mit spezieller Indikation werden Fernröntgenfrontalaufnahmen entsprechend weniger häufig angefertigt. Cranio-faciale und transversale Asymmetrien sind die Hauptindikationen zur Fernröntgenfrontalanalyse. Patienten mit einer Asymmetrie ohne Grundlage einer syndromalen Manifestation stellen mit über 50% an der Indikation die grösste Anzahl dar. Zusätzliche Indikationen sind die unilaterale mandibuläre Hyper- bzw. Hypoplasie sowie Störungen der Maxilla-Breiten-Entwicklung, gefolgt vom Komplex der cranio-facialen Syndrome. Insgesamt konnten 20715 Röntgenaufnahmen von 9283 Patienten in dem ausgewiesenen Zeitraum erfasst und statistisch analysiert werden

The complete digital workflow in fixed prosthodontics: a systematic review

Background The continuous development in dental processing ensures new opportunities in the field of fixed prosthodontics in a complete virtual environment without any physical model situations. The aim was to compare fully digitalized workflows to conventional and/or mixed analog-digital workflows for the treatment with tooth-borne or implant-supported fixed reconstructions. Methods A PICO strategy was executed using an electronic (MEDLINE, EMBASE, Google Scholar) plus manual search up to 2016–09-16 focusing on RCTs investigating complete digital workflows in fixed prosthodontics with regard to economics or esthetics or patient-centered outcomes with or without follow-up or survival/success rate analysis as well as complication assessment of at least 1 year under function. The search strategy was assembled from MeSH-Terms and unspecific free-text words: {((“Dental Prosthesis” [MeSH]) OR (“Crowns” [MeSH]) OR (“Dental Prosthesis, Implant-Supported” [MeSH])) OR ((crown) OR (fixed dental prosthesis) OR (fixed reconstruction) OR (dental bridge) OR (implant crown) OR (implant prosthesis) OR (implant restoration) OR (implant reconstruction))} AND {(“Computer-Aided Design” [MeSH]) OR ((digital workflow) OR (digital technology) OR (computerized dentistry) OR (intraoral scan) OR (digital impression) OR (scanbody) OR (virtual design) OR (digital design) OR (cad/cam) OR (rapid prototyping) OR (monolithic) OR (full-contour))} AND {(“Dental Technology” [MeSH) OR ((conventional workflow) OR (lost-wax-technique) OR (porcelain-fused-to-metal) OR (PFM) OR (implant impression) OR (hand-layering) OR (veneering) OR (framework))} AND {((“Study, Feasibility” [MeSH]) OR (“Survival” [MeSH]) OR (“Success” [MeSH]) OR (“Economics” [MeSH]) OR (“Costs, Cost Analysis” [MeSH]) OR (“Esthetics, Dental” [MeSH]) OR (“Patient Satisfaction” [MeSH])) OR ((feasibility) OR (efficiency) OR (patient-centered outcome))}. Assessment of risk of bias in selected studies was done at a ‘trial level’ including random sequence generation, allocation concealment, blinding, completeness of outcome data, selective reporting, and other bias using the Cochrane Collaboration tool. A judgment of risk of bias was assigned if one or more key domains had a high or unclear risk of bias. An official registration of the systematic review was not performed. Results The systematic search identified 67 titles, 32 abstracts thereof were screened, and subsequently, three full-texts included for data extraction. Analysed RCTs were heterogeneous without follow-up. One study demonstrated that fully digitally produced dental crowns revealed the feasibility of the process itself; however, the marginal precision was lower for lithium disilicate (LS2) restorations (113.8 μm) compared to conventional metal-ceramic (92.4 μm) and zirconium dioxide (ZrO2) crowns (68.5 μm) (p < 0.05). Another study showed that leucite-reinforced glass ceramic crowns were esthetically favoured by the patients (8/2 crowns) and clinicians (7/3 crowns) (p < 0.05). The third study investigated implant crowns. The complete digital workflow was more than twofold faster (75.3 min) in comparison to the mixed analog-digital workflow (156.6 min) (p < 0.05). No RCTs could be found investigating multi-unit fixed dental prostheses (FDP). Conclusions The number of RCTs testing complete digital workflows in fixed prosthodontics is low. Scientifically proven recommendations for clinical routine cannot be given at this time. Research with high-quality trials seems to be slower than the industrial progress of available digital applications. Future research with well-designed RCTs including follow-up observation is compellingly necessary in the field of complete digital processing

Accuracy of a chairside intraoral scanner compared with a laboratory scanner for the completely edentulous maxilla: An in vitro 3-dimensional comparative analysis

Statement of problem: Intraoral scanners are promising options for removable prosthodontics. However, analog aids, including occlusion rims, are still used, as a completely digital workflow is challenging and scientific evidence on the topic is scarce. Purpose: The purpose of this in vitro study was to assess and compare the trueness and precision of scans obtained from a reference typodont of a completely edentulous maxilla by using an intraoral scanner (TRIOS 3 Pod; 3Shape A/S) with scans obtained by using a laboratory scanner (DScan 3; EGS S.R.L.) from both Type IV stone casts and polysulfide impressions. Material and methods: The polyurethane resin reference typodont was replicated from a clinical cast and was scanned with a metrological machine to obtain a reference scan. Ten digital casts were obtained by applying standardized scanning strategies to the reference typodont with the intraoral scanner. A device was created to make 10 consistent polysulfide impressions, and a scan of each impression was made with the laboratory scanner and then digitally reversed to obtain 10 digital reversed casts. Ten Type IV stone casts were poured and then scanned with the laboratory scanner to obtain 10 digital extraoral scanner casts. The scans in standard tessellation language (STL) format were imported into a dedicated software program, and the trueness and precision were calculated in μm. In addition to descriptive statistics (confidence interval 95%), 1-way ANOVA followed by the Bonferroni test or the Kruskal-Wallis and the Dunn tests were used to analyze differences among groups (α=.05). Results: The trueness values (95% confidence interval) were digital intraoral scanner cast=48.7 (37.8-59.5), digital reversed cast=249.9 (121.3-378.5), and digital extraoral scanner cast=308.8 (186.6-430.9); significant differences were detected between digital intraoral scanner cast and digital reversed cast (P<.001) and between digital IOS casts and digital extraoral scanner cast (P<.001). The precision values (95% confidence interval) were digital intraoral scanner cast=46.7 (29.7-63.7), digital reversed cast=271.2 (94.6-447.8), and digital extraoral scanner cast=341.4 (175.5-507.3); significant differences were detected between digital intraoral scanner cast and digital reversed cast (P=.003) and between digital intraoral scanner cast and digital extraoral scanner cast (P=.001). Conclusions: Directly scanning a solid typodont of a completely edentulous maxilla with the intraoral scanner produced better trueness and precision than scanning the polysulfide impressions or the stone casts with a laboratory scanner

Comparison of different intraoral scanning techniques on the completely edentulous maxilla: An in vitro 3-dimensional comparative analysis

Statement of problem: Information about the accuracy of intraoral scanners for the edentulous maxilla is lacking. Purpose: The purpose of this in vitro study was to compare the accuracy of 3 different intraoral scanner techniques on a completely edentulous maxilla typodont. Material and methods: Two completely edentulous maxillary typodonts with (wrinkled typodont) and without (smooth typodont) palatal rugae were used as reference and were scanned by using an industrial metrological machine to obtain 2 digital reference scans in standard tessellation language (STL) format (dWT and dST). Three different scanning techniques were investigated: in the buccopalatal technique, the buccal vestibule was scanned with a longitudinal movement ending on the palatal vault with a posteroanterior direction; the S-shaped technique was based on an alternate palatobuccal and buccopalatal scan along the ridge; in the palatobuccal technique, the palate was scanned with a circular movement and then with a longitudinal one along the buccal vestibule. Consecutively, 6 types of scans were obtained (n=10), namely wrinkled typodont/buccopalatal technique, wrinkled typodont/S-shaped technique, wrinkled typodont/palatobuccal technique (wrinkled typodont), smooth typodont/buccopalatal technique, smooth typodont/S-shaped technique, and smooth typodont/palatobuccal technique (smooth typodont). Scans in STL format were imported into a dedicated software program, and trueness and precision were evaluated in μm. In addition to descriptive statistics (95% confidence interval), a 2-factor ANOVA on the data ranks, the Kruskal-Wallis, and the Dunn tests were performed to analyze differences among groups (α=.05). Results: Mean values for trueness (95% confidence interval) were wrinkled typodont/buccopalatal technique=48.7 (37.8-59.5); wrinkled typodont/S-shaped technique=65.9 (54.9-77.4); wrinkled typodont/palatobuccal technique=109.7 (96.1-123.4); smooth typodont/buccopalatal technique=48.1 (42.4-53.7); smooth typodont/S-shaped technique=56.4 (43.9-68.9); smooth typodont/palatobuccal technique=61.1 (53.3-69), with statistically significant differences for wrinkled typodont/buccopalatal technique versus wrinkled typodont/palatobuccal technique (P<.001), buccopalatal technique versus palatobuccal technique (P<.001), and wrinkled typodont versus smooth typodont (P=.002). Mean values for precision (95% confidence interval) were wrinkled typodont/buccopalatal technique=46.7 (29.7-63.7); wrinkled typodont/S-shaped technique=53.6 (37.6-69.7); wrinkled typodont/palatobuccal technique=90 (59.1-120.9); smooth typodont/buccopalatal technique=46 (39.7-52.3); smooth typodont/S-shaped technique=76 (55.5-96.6); smooth typodont/palatobuccal technique=52.9 (41.9-63.8); with statistically significant differences for buccopalatal technique versus palatobuccal technique (P=.032) and wrinkled typodont/buccopalatal technique versus wrinkled typodont/palatobuccal technique (P=.012). Conclusions: Smooth typodont scans showed better trueness than wrinkled typodont scans. Buccopalatal technique showed better mean values for trueness and precision than palatobuccal technique only in the wrinkled typodont scenario, while the other scanning approaches did not show significant differences in either tested configuration

Monolithic implant‐supported lithium disilicate (LS2) crowns in a complete digital workflow: A prospective clinical trial with a 2‐year follow‐up

Background: The technical development of digital processing allows the production of anatomically full‐contoured implant‐supported restorations. Purpose: The aim of this prospective clinical trial was to analyze the treatment concept of monolithic lithium disilicate (LS2) single‐unit restorations in a complete digital workflow. Material and Methods: Forty‐four patients were restored with 50 screw‐retained monolithic implant LS2 crowns bonded to pre‐fabricated titanium abutments on soft tissue level implants (Institut Straumann AG, Basel, Switzerland) in premolar and molar sites. All implant restorations were digitally designed after intraoral optical scanning (IOS) and CAD/CAM‐processing without physical model situations. Study participants were clinically and radiographically examined based on an annually performed follow‐up. The “Functional Implant Prosthodontic Score” (FIPS) was applied for objective outcome assessment after 2 years of loading. Five variables were defined for FIPS evaluation, resulting in a maximum score of 10 per implant restoration. Descriptive statistics were calculated for mean scores standard deviations, medians, and Q₂₅–Q₇₅. Results: All patients could be successfully treated within two clinical appointments. No clinical modifications were necessary for the seating of the monolithic crowns, neither for interproximal nor occlusal sites. The implant LS2 restorations demonstrated survival rates of 100% without any technical or biological complications after 2 years. The mean total FIPS score was 7.7 ± 1.0, ranging from 6 to 10. Conclusions: CAD/CAM‐produced monolithic implant crowns out of LS2 in a complete digital workflow seem to be a feasible treatment concept for the rehabilitation of single‐tooth gaps in posterior sites under mid‐term observation

Digital technology in fixed implant prosthodontics

Digital protocols are increasingly influencing prosthodontic treatment concepts. Implant-supported single-unit and short-span reconstructions will benefit mostly from the present digital trends. In these protocols, monolithic implant crowns connected to prefabricated titanium abutments, which are created based on data obtained from an intraoral scan followed by virtual design and production, without the need of a physical master cast, have to be considered in lieu of conventional manufacturing techniques for posterior implant restorations. No space for storage is needed in the complete digital workflow, and if a remake is required a replica of the original reconstruction can be produced quickly and inexpensively using rapid prototyping. The technological process is split into subtractive methods, such as milling or laser ablation, and additive processing, such as three-dimensional printing and selective laser melting. The dimensions of the supra-implant soft-tissue architecture can be calculated in advance of implant placement, according to the morphologic copy, and consequently are individualized for each patient. All these technologies have to be considered before implementing new digital dental workflows in daily routine. The correct indication and application are prerequisite and crucial for the success of the overall therapy, and, finally, for a satisfied patient. This includes a teamwork approach and equally affects the clinician, the dental assistant and the technician as well. The digitization process has the potential to change the entire dental profession. The major benefits will be reduced production costs, improvement in time efficiency and fulfilment of patients’ perceptions of a modernized treatment concept

Precision of maxillo-mandibular registration with intraoral scanners in vitro

Purpose: To compare the precision of maxillo-mandibular registration and resulting full arch occlusion produced by three intraoral scanners in vitro. Methods: Six dental models (groups A–F) were scanned five times with intraoral scanners (CEREC, TRIOS, PLANMECA), producing both full arch and two buccal maxillo-mandibular scans. Total surface area of contact points (defined as regions within 0.1 mm and all mesh penetrations) was measured, and the distances between four pairs of key points were compared, each two in the posterior and anterior. Results: Total surface area of contact points varied significantly among scanners across all groups. CEREC produced the smallest contact surface areas (5.7–25.3 mm2), while PLANMECA tended to produce the largest areas in each group (22.2–60.2 mm2). Precision of scanners, as measured by the 95% CI range, varied from 0.1–0.9 mm for posterior key points. For anterior key points the 95% CI range was smaller, particularly when multiple posterior teeth were still present (0.04–0.42 mm). With progressive loss of posterior units (groups D–F), differences in the anterior occlusion among scanners became significant in five out of six groups (D–F left canines and D, F right canines, p < 0.05). Conclusions: Maxillo-mandibular registrations from three intraoral scanners created significantly different surface areas of occlusal contact. Posterior occlusions revealed lower precision for all scanners than anterior. CEREC tended towards incorrect posterior open bites, whilst TRIOS was most consistent in reproducing occluding units

Measurement of Trace Water Vapor in a Carbon Dioxide Removal Assembly Product Stream

The International Space Station Carbon Dioxide Removal Assembly (CDRA) uses regenerable adsorption technology to remove carbon dioxide (COP) from cabin air. Product water vapor measurements from a CDRA test bed at the NASA Marshall Space Flight Center were made using a tunable infrared diode laser differential absorption spectrometer (TILDAS) provided by NASA Glenn Research Center. The TILDAS instrument exceeded all the test specifications, including sensitivity, dynamic range, time response, and unattended operation. During the COP desorption phase, water vapor concentrations as low as 5 ppmv were observed near the peak of CO2 evolution, rising to levels of approx. 40 ppmv at the end of a cycle. Periods of high water concentration (>100 ppmv) were detected and shown to be caused by an experimental artifact. Measured values of total water vapor evolved during a single desorption cycle were as low as 1 mg

Preparation, analysis, and application of coated glass targets for the Wendelstein 7-X laser blow-off system

Coated glass targets are a key component of the Wendelstein 7-X laser blow-off system that is used for impurity transport studies. The preparation and analysis of these glass targets as well as their performance is examined in this paper. The glass targets have a high laser damage threshold and are coated via physical vapor deposition with μm thick films. In addition, nm-thin layers of Ti are used as an interface layer for improved ablation efficiency and reduced coating stress. Hence, the metallic or ceramic coating has a lateral homogeneity within 2% and contaminants less than 5%, being optimal for laser ablation processing. With this method, a short (few ms) and well defined pulse of impurities with about 1017 particles can be injected close to the last closed flux surface of Wendelstein 7-X. In particular, a significant amount of atoms with a velocity of about 1 km/s enters the plasma within 1 ms. The atoms are followed by a negligible concentration of slower clusters and macro-particles. This qualifies the use of the targets and applied laser settings for impurity transport studies with the laser blow-off system in Wendelstein 7-X. © 2020 Author(s)