Spencerdonnelly5729
Creating wax-ups of missing teeth for backward-planning in implant surgery is a complex and time-consuming process. To facilitate implant-planning procedures, the automatic generation of a virtual wax-up would be useful. In this study, the reconstruction of missing teeth in partially edentulous patients was performed automatically using a newly developed software. The accuracy was investigated in order to test its clinical applicability.
This study presents a new method for creating an automatic virtual wax-up, which could serve as a basic tool in modern implant planning procedures. First, a statistical shape model (SSM) based on 76 lower and upper arch scans from dentally healthy individuals was generated. Then artificially generated tooth gaps were reconstructed. The accuracy of the workflow was calculated using a Leave-One Out cross validation (LOOCV) and was given as median deviation (mm). Scans of three clinical cases with partial edentulism were equally reconstructed using the SSM and compared to th, the presented method offers a fast and viable way for the approximate placement of missing crowns. This could be used in a digital planning workflow when implant position must be determined.
A first feasibility of creating virtual wax-26 ups using a SSM could be shown. Artificially generated tooth gaps could be reconstructed close to original with the proposed workflow. Dyes chemical In the clinical cases the SSM proposes an anatomical reconstruction, which does not yet consider prosthodontic aspects. To obtain clinical use contact to antagonist teeth must be considered and more training data must be implemented. However, the presented method offers a fast and viable way for the approximate placement of missing crowns. This could be used in a digital planning workflow when implant position must be determined.
The aim of this study was to present the different stages of prosthetic treatment planning involved in the design of an esthetic smile and improving masticatory function using CAD/CAM technology.
The patient underwent the following tests and procedures CBCT cone beam computed tomography (CS9300, Carestream, USA), intraoral scans and occlusal detection (CS3600, Carestream, USA), a portrait session (Nikon D610, Tokyo, Japan), a face scan (Bellus 3D FaceApp, iPhone XS, Apple ) and registration of individual TMJ angles and mandibular movements with a Zebris for Ceramill device (Amman Girrbach, Germany). All the data were transferred to a Ceramill Mind software (Amman Girrbach, Germany) where they were integrated. The face scan and photos were superimposed on the CBCT. Scans of the dental arches were combined with the CBCT. On this CBCT basis, position of the condyles in the articular fossae was determined.. A Virtual Artex CR articulator (Amann Girrbach, Germany) was attached to the 3D object. Individual TMJ angles and mandibular movements were then introduced.
A virtual patient was created in the Ceramil Mind software. The optimal shape and position of each tooth were designed into the programme The wax-up was printed using a 3D printer and a temporary mock-up and final restoration were made for the patient. In te same time, the aesthetics of the smile was improved and a harmonious central occlusion and articulation were obtained on virtual models and in in the patient's oral cavity.
The presented digital planning protocol allows to work out an optimal solution in complicated patient cases from a functional and aesthetic point of view.
The presented digital planning protocol allows to work out an optimal solution in complicated patient cases from a functional and aesthetic point of view.
To assess the clinical status of monolithic zirconia CAD/CAM endocrowns and crowns on post and core buildups in endodontically treated molars after 5 years of clinical service.
A total of 670 patients who received restorations for excessive defects at Ansteel Group Hospital from 2012 to 2015 were selected and randomly divided into two groups 334 patients in the endocrown group and 336 in the post and core crown group. All the treatments were performed using a digital CAD/CAM system. The prostheses restorations at 1, 3, and 5 years after treatment were evaluated using the USPHS (United States Public Health Service) criteria and satisfaction questionnaire. In addition, the time cost of tooth preparation was recorded by the clinicians.
Most of the patients in both groups reported grade A at the after-treatment follow-ups. Gingival health, food impaction, marginal accuracy, and general satisfaction at 3 and 5 years after treatment in the endocrown group rated higher (P < 0.05) than in the post and core crown group. There was no statistical difference in other indicators between the two groups at all observational after-treatment timepoints (P > 0.05). The time cost of tooth preparation in the post and core crown group was significantly higher than that in the endocrown group.
A CAD/CAM scanning system combined with a monolithic zirconia endocrown restoration was rated very positively by the participants. Endocrown restorations are a significantly superior choice compared with post and core crowns in clinical application. (Int J Comput Dent 2022;25(3)287-294; doi 10.3290/j.ijcd.b2599661).
A CAD/CAM scanning system combined with a monolithic zirconia endocrown restoration was rated very positively by the participants. Endocrown restorations are a significantly superior choice compared with post and core crowns in clinical application. (Int J Comput Dent 2022;25(3)287-294; doi 10.3290/j.ijcd.b2599661).
The present study aimed to determine the impact of different degrees of salivary contamination and variations in occlusal force during intraoral scanning of inlay/onlay cavities on the accuracy of fine structure reconstruction and occlusal records.
Digital data of inlay/onlay models, collected using an intraoral scanner, were divided into 40 groups according to the restoration type (onlay or inlay), salivary contamination level (none, completely dry; mild, moist but not visually completely apparent; moderate, half-filled cavity; severe, filled-up cavity), and simulated occlusal force (0, 2, 4, 6 or 8 kg). The acquired 120 datasets were used to measure the average interocclusal space and cavity buccolingual internal angle.
Salivary contamination and occlusal force did affect the occlusal contact (P < 0.001), but restoration type did not (P > 0.05). An interaction was found between inlay type and salivary contamination (P < 0.001), but not between occlusal force and salivary contamination (P >t salivary contamination is acceptable. (Int J Comput Dent 2022;25(3)257-265; doi 10.3290/j.ijcd.b2599691).
The present in vitro study aimed to evaluate the stress distribution patterns, resistance to fracture, and failure modes of endodontically treated molars restored with different cuspal coverage options.
Three-dimensional models of mandibular first molars with six kinds of typical cuspal coverage were generated T1 mesiobuccal cuspal coverage; T2 coverage of all buccal cusps; T3 mesiolingual cuspal coverage; T4 coverage of all lingual cusps; T5 mesiobuccal and mesiolingual cuspal coverage; T6 coverage of all cusps. All restorations were fabricated with zirconia-reinforced lithium silicate ceramic. The stress and its distributions under axial and oblique loading were analyzed by finite element analysis (FEA). Sixty human mandibular molar samples were randomly allocated into six groups (n = 10) to simulate the application of six types of restorations with different cuspal coverage, as in the FEA analysis, and were then subjected to a compressive test. All fractured specimens were subjected to fractography. Daarable effects to coverage of all cusps in endodontically treated molars, and both methods exhibited a more even stress distribution and fracture resistance and better mechanical performance in high occlusal areas than other types of cuspal coverage. (Int J Comput Dent 2022;25(3)267-276; doi 10.3290/j.ijcd.b2599709).
The purpose of the present study was to report early surgical template-related and postoperative complications of computer-guided implant placement and to evaluate its accuracy.
Data were collected retrospectively from records of patients who had undergone computer-guided implant surgery between 2016 and 2018. Incidence of early surgical template-related and postoperative complications was recorded. Accuracy of implant placement was evaluated by comparing the data from postoperative CBCT records with that from the preoperative virtual implant planning by using appropriate image registration software. Depth, coronal, apical, and angular deviations were measured.
A final number of 27 partially edentulous patients who received 52 implants with 31 static surgical templates were included in the study. All implants had been inserted in a fully guided manner using a flapless technique and following a one-stage approach. All implants were reported to have been successfully osseointegrated. Except for one templa
The aim of this prospective study is to evaluate the accuracy of 3-dimensional (3D) orthognathic surgical planning and CAD/CAM splints by comparing planned versus actual postoperative outcomes.
Ten patients scheduled for bimaxillary orthognathic surgery to correct a Skeletal III dentofacial deformity were recruited for this prospective "proof of concept" study. All subjects had cone beam computed tomography (CBCT) taken not more than 2 months preoperatively and within the 1-week postoperative period. The distance between 6 dental landmarks (midpoint of maxillary and mandibular incisors, mesio-buccal cusps of the first maxillary and mandibular molars) and 3 intersecting symmetry planes [Frankfurt horizontal plane (FHP), mid-sagittal plane (MSP) and coronal plane (CP)] were measured and the differences between the virtually simulated and actual post-operative models were computed. The threshold for accuracy was set at 2mm.
Differences between planned and actual outcomes were analyzed via Chi-square tests r-inferior direction, indicating a greater surgical error in achieving the desired vertical position of the maxilla-mandibular complex.
To present an image-processing measurement algorithm to evaluate the transfer accuracy of indirect bonding (IDB) trays, exemplified by a CAD/CAM-based IDB tray integrated into a digital orthodontic workflow.
Plaster casts of 24 patients with full dentition and different malocclusions were scanned with an intraoral scanner (Trios; 3Shape, Copenhagen, Denmark) to obtain digital models, which served for the virtual placement of orthodontic brackets in simulation software (OnyxCeph; Image Instruments, Chemnitz, Germany). The resulting STL files were sent to a dental laboratory (CA Digital; Hilden, Germany) for the production of INDIVIDUA IDB trays. These trays were used to transfer the brackets to the respective plaster casts. Finally, a second scan was performed to record the actual bracket positions. The transfer accuracy was then analyzed by a measurement algorithm scripted to automation, which calculated the deviations of the planned and real bracket positions with a local best-fit alignment, resulting in three linear and three angular measurements for each bracket.
