EditorialPubMed-ID: 32207455Seiten: 3-4, Sprache: Deutsch, Englisch
EditorialPubMed-ID: 32207456Seiten: 5-6, Sprache: Deutsch, Englisch
SciencePubMed-ID: 32207457Seiten: 11-16, Sprache: Deutsch, Englisch
Aim: The present study aimed to evaluate intraoral microsensors for the objective measurement of patient compliance during splint therapy and to comparatively analyze the duration of mandibular and maxillary splint application in patients with myofascial pain.
Materials and methods: Thirty-two patients with sole myofascial pain without limited opening (Research Diagnostic Criteria for Temporomandibular Disorders [RDC/TMD] Ia) were divided into two groups. To ensure patient comparability, all pressure-sensitive sites from the initial palpation were summarized as pain scores. The subjects in group 1 were treated with maxillary stabilization splints, and those in group 2 with mandibular stabilization splints. All splints were equipped with a microsensor without interfering static or dynamic occlusion. Wear pattern was recorded at three intervals of 30 days each. Following the observation period, the data were retrieved and statistically evaluated using multi-factor analysis of variance (ANOVA) and the Bland-Altman analysis.
Results: During the observation period, maxillary splints were applied in 44.4% and mandibular splints in 44.2% of the days. Regarding patient compliance, there was no significant difference between the maxillary and mandibular splints (P = 0.359). Patients with an increased pain score (P < 0.0001) and female patients (P = 0.013) wore their splints significantly more often. The wear time decreased over the observation period, whereas only the initial and terminal interval differed significantly across both the mandibular and maxillary splint groups (P < 0.0001).
Conclusion: The microsensor used in the present study was an effective and reliable tool for monitoring patient compliance in patients with temporomandibular disorders (TMD). This method also allows for the reliable recording of intraoral splint application prior to the required bite elevations. The two types of splints analyzed in the present study had no significant influence on compliance.
Schlagwörter: microsensor, splint therapy, compliance, myofascial pain, sensor-based monitoring, temporomandibular disorders
SciencePubMed-ID: 32207458Seiten: 17-26, Sprache: Deutsch, Englisch
When recording condylar movement paths with the aid of electronic measuring systems, it is often found that, especially in jaw opening and closing movements, excursive and incursive paths of movement are not congruent but run separately, independently of one another to a greater or lesser degree. The objective of the study was to investigate this phenomenon in the context of rotation vs translation behavior, also taking into consideration additional side-specific condylar movement patterns. For this purpose, the electronic movement records of habitual jaw opening of 259 participants of the associated project of the population-representative basic study SHIP 0 were evaluated. The condylar movement path (condylar tracing, ConTrac) at the arbitrary axis point, the excursion vs incursion behavior in the condylar tracing grid (ExInGrid), and the rotation vs translation behavior (RotTrans) were classified, and the translational condylar path and the maximum angle of rotation were determined metrically. Relationships between the parameters ConTrac, ExInGrid, and RotTrans were statistically analyzed using cross tabulations and Spearman's correlation coefficient. Only about 18% of ConTrac showed congruence of excursive and incursive movement path components, while 39% demonstrated noncongruent paths, and 43% showed further conspicuous features in the movement path. For the parameter ExInGrid, recognizable to highly pronounced loop formation patterns to a degree of 89% were observed in the condylar tracing grid. An average of 12.5 mm (min 2.1 mm, max 21.7 mm) was determined for the purely translational component of the condylar movement path, and 32.1 degrees (min 12 degrees, max 45 degrees) for the maximum angle of rotation. Concerning the rotation vs translation behavior, the linear basic pattern occurred at around 9%; the sigmoidal pattern at 28%; and the hysteretic, loopy or irregular pattern at 63%. The parameters RotTrans and ExInGrid showed a strong correlation, whereas the strength of the correlation for ConTrac and ExInGrid or RotTrans and ConTrac was evaluated as weak or very weak. The rotation vs translation behavior influences condylar movement paths in the positional relationship of excursive and incursive components. The visualization of several condylar movement paths in the form of a condylar tracing grid helps to capture complex rotational and translational motion components of the real condyles more effectively than the assessment of a single condylar movement path.
Schlagwörter: population-based values of mandibular function, condylar movement path, functional diagnostics, jaw tracking, rotation vs translation relationship
SciencePubMed-ID: 32207459Seiten: 27-37, Sprache: Deutsch, Englisch
Objective: The objective of this narrative review was to summarize the current status and future perspectives of additive manufacturing (AM) technologies with a particular emphasis on manufacturing zirconia-based materials. AM technologies include vat photopolymerization, material jetting, material extrusion, selective laser sintering (SLS), and selective laser melting (SLM) technologies based on either powder bed fusion (PBF) technologies or direct energy deposition, or sheet lamination based on binder jetting technologies.
Materials and methods: A comprehensive literature review was performed, specifically evaluating AM technologies assigned for processing zirconia. An electronic database search was performed using keywords and MeSH terms. The search was confined to full-text articles written in English and published in peer-reviewed journals between 1999 and 2018.
Results: A total of 62 articles were included in this review, of which 56 described the AM processes and 6 reported on AM applications in the field of dentistry. A broad diversity of literature exists regarding AM technologies for ceramic materials, which complicates the establishment of a classification system for the current AM technologies for zirconia. The variations in the composition of zirconia slurries or mixtures across different technologies often made it difficult to identify the proper nature of such information. Mechanical properties of printed zirconia materials utilizing different technologies were investigated through a wide range of tests. Overall, the review indicates that manufacturing zirconia using AM technologies could be achieved without issues, but mechanical properties appear to be poor compared with conventional manufacturing procedures.
Conclusions: The results of this review indicate the necessity for further potential improvement in AM technologies for manufacturing zirconia reconstructions along with advances in material composition before zirconia could be considered as a material for standard care.
Schlagwörter: 3D printing, additive manufacturing, dental ceramic, stereolithography, zirconia
SciencePubMed-ID: 32207460Seiten: 39-48, Sprache: Deutsch, Englisch
The Dental Motion Decoder system (DMS-System) is a medical device based on magnetic field technology that records mandible movements. The data can be used to program an articulator or can be directly processed over a computer-aided design (CAD) interface. The present study aimed to assess the reproducibility of this system in vitro and in vivo.
Material and methods: Protrusive and laterotrusive movements were simulated in vitro using an articulator (SAM SE) (Group M) and in vivo (Group P) on one test individual. Measurements were carried out in two ways: 1) Measurements were taken after initializing and referencing the system using the reference points (RPs) once, followed by 30 protrusive and laterotrusive movements (M1 and P1); and 2) Thirty individual measurements were recorded using the RPs before each measurement (M2 and P2). Values for the sagittal condylar path inclination angle (sCPIA) and the Bennett angle (BA) were exported and analyzed. The reproducibility of the system was evaluated using the standard deviations (SDs) of the measurement series (sCPIA and BA for M1, M2, P1, and P2).
Results: In vitro tests M1 (SD: sCPIA = 0.08 degrees; BA = 0.06 degrees) and M2 (SD: sCPIA = 0.26 degrees; BA = 0.11 degrees) showed significantly higher reproducibility (P < 0.001) compared with the in vivo measurements P1 (SD: sCPIA = 0.61 degrees; BA = 0.45 degrees) and P2 (SD: sCPIA = 1.4 degrees; BA = 0.65 degrees).
Conclusion: Within the limitations of the present study, the deviation in vitro, representing the reproducibility of the DMD-System, is smaller than the biologic variance observed in vivo. Therefore, reliable measurements under clinical conditions can be assumed.
Schlagwörter: axiography, digital workflow, virtual articulator, digital articulator, functional analysis, condylar path inclination angle
SciencePubMed-ID: 32207461Seiten: 49-56, Sprache: Deutsch, Englisch
Ziel: Evaluation eines geeigneten Modells für computer-aided design (CAD)/ computer-aided manufacturing (CAM)-in-vitro-Studien durch die Untersuchung häufig verwendeter Modellmaterialien hinsichtlich Eignung für Intraoralscanner und Dimensionsstabilität
Material und Methode: Nach Vorlage eines für eine zehngliedrige Brücke präparierten Typodont-Modells wurden je ein Modell aus Superhartgips Typ IV (DS), Kobalt-Chrom-Molybdän (CoCr), Epoxidharz (EPOX), Polyurethan (PU), Titan (TI) und Zirkonoxid (ZI) hergestellt. Mit einem Intraoralscanner wurden drei Scans je Modell erstellt. Um die Richtigkeit der Intraoralscans zu beurteilen, wurde der jeweils erste Scan mit dem zugehörigen Referenz-Datensatz verglichen. Der Referenz-Datensatz wurde mit Mikro-Computertomografie (Mikro-CT) generiert. Die Präzision wurde ermittelt, indem die Intraoralscans eines Modells miteinander verglichen wurden. Für die Untersuchung der Dimensionsstabilität wurden mit dem Mikro-CT dreidimensionale Datensätze über einen Zeitraum von sechs Wochen erstellt. Die Datensätze wurden mit einer Software analysiert, die die Abweichungen zwischen zwei Datensätzen unter Verwendung eines Best-fit-Algorithmus berechnet. Die Modelle wurden während der gesamten Studie unter konstanten Bedingungen gelagert.
Ergebnisse: Das Kriterium der Richtigkeit wird von Kobalt-Chrom-Molybdän, Epoxidharz, Polyurethan und dem Typodont-Modell erfüllt. Die Scans von Kobalt-Chrom-Molybdän und Zirkonoxid zeigen die beste Präzision. Polyurethan und das Typodont-Modell erfüllen das Kriterium der Dimensionsstabilität nicht, wohingegen Epoxidharz und Superhartgips für zehn Tage als dimensionsstabil erachtet werden können.
Schlussfolgerung: Das Kobalt-Chrom-Molybdän-Modell ist das einzige Modell, das alle Anforderungen für ein geeignetes Modell für CAD/CAM-in-vitro-Studien erfüllt. Die anderen untersuchten Materialien zeigen entweder mangelnde Dimensionsstabilität oder können nicht adäquat mit dem Intraoralscanner erfasst werden.
Schlagwörter: CAD/CAM, Genauigkeit, digitale Abformung, Modellmaterialien, in vitro, Intraoralscanner
ApplicationPubMed-ID: 32207462Seiten: 57-71, Sprache: Deutsch, Englisch
Aim: An orthodontic treatment is described that combines the use of clear aligners and computer-guided piezocision to overcome the drawbacks of traditional corticotomy in accelerating orthodontic tooth movement. The relapse at the 2-year follow-up was also evaluated.
Materials and methods: A 13-year-old male patient was selected and treated due to a molar Class II malocclusion with moderate dental crowding. Treatment time, oral health-related quality of life (OHRQoL), and periodontal indexes were assessed. To reduce the treatment time, computer-guided piezocision was utilized to perform flapless interproximal corticotomy cuts through the depth of the cortical bone. The orthodontic therapy using clear aligners began on the same day as the surgery.
Results: The overall duration of the therapy was 6 months. There was an improvement in the periodontal indexes at the end of the therapy. An aggravation of OHRQoL only occurred for 3 days after surgery. The 2-year follow-up evaluation showed a relapse of 0.2 mm on the maxillary left lateral incisor and 0.25 mm on the mandibular right lateral incisor.
Conclusion: The present case report describes the advantages of a combination of computer-guided piezocision and clear aligners to treat a Class II malocclusion with moderate crowding.
Schlagwörter: clear aligner appliance, CAD/CAM, accelerated tooth movement, orthodontics, piezocision, quality of life
ApplicationPubMed-ID: 32207463Seiten: 73-82, Sprache: Deutsch, Englisch
Background: Accurate implant placement in the bone is key to successful implant treatment. Once inserted, it can be difficult to correct the orientation of the implant axis, especially of a one-piece implant. Prosthetic-driven digital implant planning in combination with fully guided implant surgery can offer additional safety in such cases.
Case presentation: The patient presented with a wide, edentulous interdental space extending from sites 13 to 16, which was to be restored with three one-piece zirconia implants supporting a zirconia fixed partial denture comprizing a cantilever to the mesial aspect. Digital planning based on DICOM (Digital Imaging and Communications in Medicine) and intraoral surface data was performed to ensure optimal positioning. Guided implant placement was executed using a contra-angle handpiece with special attachments and a compatible, sleeveless drill guide. Impressions of the implants for the final restoration were acquired using an intraoral scanner. Reflection-related errors were compensated for by using the given digital abutment geometry. The DICOM and STL datasets were superimposed and used as the basis for fabricating a monolithic zirconia restoration through a subtractive milling process. The final restoration was adhesively cemented.
Conclusions: By using a prosthetic-driven implant planning strategy, it was possible to place the one-piece ceramic implants without an available implant manufacturer's guide-based solution. This was accomplished using a contra-angle surgical handpiece with special attachments and a compatible drill guide. This approach is particularly recommended for the placement of one-piece implants, which otherwise require irreversible abutment grinding for the adjustment of the implant axis orientation after placement. To increase the precision of the digital impressions of the implants, the ideal abutment geometry was imported and superimposed onto the scan data. The results demonstrate that the proposed method can dispense with the need for gingival retraction when acquiring impressions for implants of this type in the future.
Schlagwörter: ceramic implants, guided implant surgery, backward planning, intraoral scan, CAD/CAM, digital workflow,
ApplicationPubMed-ID: 32207464Seiten: 83-91, Sprache: Deutsch, Englisch
Aim: This article introduces a new milling unit (Cerec Primemill, Dentsply Sirona). Clinical cases show how this new milling unit functions to improve the overall workflow of single-visit chairside dentistry.
Materials and Methods: The unit has a touchscreen that guides the user through the process of setting up the manufacturing job. This process, along with the pretouch process, is completed prior to the procedure. In addition to the guided workflow, the milling unit has a new block scanner and a radio-frequency identification (RFID) reader for bur identification/monitoring. It also has new milling tools and manufacturing algorithms and uses a unique parallel milling strategy with zirconia and a novel grinding strategy with glass-ceramic.
Results: The optimized tool geometries and manufacturing algorithms along with new mechanical and electronic components allow for an improvement in quality and speed.
Schlagwörter: machining strategy, workflow, touch interface, color-coded cap