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Beijing Da Xue Xue Bao. Yi Xue Ban =... Feb 2024To compare the trueness of incisal guidance of implant-supported single crowns designed by patient-specific motion (PSM) with that designed by average-value virtual...
OBJECTIVE
To compare the trueness of incisal guidance of implant-supported single crowns designed by patient-specific motion (PSM) with that designed by average-value virtual articulator (AVA).
METHODS
The study had recruited 12 participants with complete dentition and stable incisal guidance. An intraoral scanner was used to scan digital casts and record two types of patient-specific motion (data only including protrusive movement, and data including protrusive movement and lateral protrusive movement). The lingual surfaces of the maxillary incisors which guided the protrusive movement was selected and elevated to create a reference cast. A maxillary central incisor of original casts was vir-tually extracted and implanted to generate a working cast. The Dental system software program was used to design implant-supported single crowns with the anatomical coping design method. The incisal guidance was designed by different methods. The incisal guidance in control group was designed by the average-value virtual articulator. The incisal guidance in experiment groups was designed by the patient-specific motion only including protrusive movement (PSM1) and with the patient-specific motion including protrusive movement and lateral protrusive movement (PSM2). The incisal guidance of prosthesis designed by these 3 methods were compared with the original incisal guidance in Geomagic Control 2015 (3DSystem, America). The measurements included: Average of positive values, ratio of positive area and maximum value reflecting supra-occlusion; average of negative values, ratio of negative area and minimum value reflecting over-correction; and root mean square reflecting overall deviation.
RESULTS
Statistical data were collected using the median (interquartile range) method. The average of positive values, ratio of positive area and average of negative values of the PSM2 group were smaller than those of the control group [8.0 (18.8) μm . 37.5 (47.5) μm; 0 . 7.2% (38.1%); -109.0 (63.8) μm .-66.5 (64.5) μm], and the ratio of negative area of PSM2 group was larger than those of the control group [52.9% (47.8%) . 17.3% (45.3%)], with significant differences ( all < 0.05). The ratio of positive area [0.1% (7.0%)] and average of negative values [-97.0 (61.5) μm] of PSM1 group, were smaller than those of the control group, and the ratio of negative area [40.7% (39.2%)] of the PSM1 group was larger than that of the control group, with significant differences ( < 0.05). The average of positive values [20.0 (42.0) μm] and ratio of positive area of PSM1 group was larger than that of the PSM2 group with significant differences ( < 0.05).
CONCLUSION
To establish the incisor guidance of implant-supported single crowns, compared with the average-value virtual articulator and the patient-specific motion only including protrusive movement, the patient-specific motion including protrusive movement and lateral protrusive movement is more conducive to reducing the protrusive interference of prosthesis and improving the occlusal fit.
Topics: Humans; Incisor; Software; Maxilla; Crowns; Movement; Computer-Aided Design
PubMed: 38318900
DOI: 10.19723/j.issn.1671-167X.2024.01.013 -
The International Journal of... Feb 2024To compare the static and dynamic occlusion of all-ceramic single crowns designed by mechanical and virtual articulators, by evalua6ng the accuracy of occlusal contacts...
PURPOSE
To compare the static and dynamic occlusion of all-ceramic single crowns designed by mechanical and virtual articulators, by evalua6ng the accuracy of occlusal contacts of prostheses designed by virtual articulators and the feasibility of clinical application of CAD/CAM virtual articulators.
MATERIALS AND METHODS
Nine subjects with an average age of 27 years who needed crown repair were recruited. After preparation of the all-ceramic crowns, two zirconia crowns were designed and fabricated through digital procedures and traditional methods. The intraoral scanner, Geomagic software, and T-Scan analyzer were used to analyze the occlusal contact points, areas, and the occlusal force percentage peak before the treatment and after the two crowns were temporarily fixed.
RESULTS
There was a significant difference in the number of occlusal contact points and areas between the mechanical group and control group (preoperation group), but there was no obvious difference between the virtual group and control group. The occlusal contact overlapping areas of the virtual-control group were significantly larger than those of the mechanical-control group. The occlusal force percentage peak of the tested teeth was slightly larger in the mechanical group than in the virtual group.
CONCLUSIONS
The posterior single crown designed by a virtual articulator restored the intercuspal occlusal better than one designed by a mechanical articulator, and it produced less dynamic occlusal interference. This finding suggests that virtual articulators can provide guidance for the design and adjustment of the occlusal surface of posterior single crown prostheses.
Topics: Humans; Adult; Dental Articulators; Crowns; Computer-Aided Design; Molar; Ceramics; Dental Prosthesis Design
PubMed: 38381992
DOI: 10.11607/ijp.8298 -
Zhonghua Kou Qiang Yi Xue Za Zhi =... Jan 2024To compare and evaluate the difference in maxillary dentition position using an anatomical facebow and jaw movement analyzer. From March to May 2023, 15 medical...
To compare and evaluate the difference in maxillary dentition position using an anatomical facebow and jaw movement analyzer. From March to May 2023, 15 medical interns from Yantai Stomatological Hospital were recruited, including 9 males and 6 females, aged 20-25 years. Digital models and plaster models of maxillary dentition were obtained from the 15 medical interns. The anatomical facebow group (AFB) and jaw movement analyzer group (JMA) were used to transfer the position of the maxillary dentition to the virtual articulator. The virtual occlusal articulator module of exocad denture design software was used to measure the inclination angle of the occlusal plane of the two groups, the distance between the mesio-incisal angle of the left maxillary central incisor and the lateral center point of the lateral condylar sphere of the virtual occlusal articulator, the distance between the mesial buccal cusp of the maxillary first molar and the lateral center point of the lateral condyle sphere of the virtual articulator. The same marks (mesial incisor point of left maxillary central incisor and mesial buccal cusp point of both maxillary first molars) were measured in two groups of maxillary dentition, and the root-mean-square error between 3 points was calculated. The occlusal plane inclination angle in AFB group (9.11°±3.85°) was significantly larger than that in JMA group (4.94°±2.69°) (=10.45, <0.001). There were significant differences between AFB and JMA groups. The distances from the mesial cusp of the left first molar to the lateral center of the left condylar, from the mesial cusp of the left maxillary central incisor to the lateral center of the left condylar[(91.75±3.05), (129.09±4.60) mm]were significantly smaller than those in the JMA group[(95.68±5.45), (132.41±5.64) mm](=-4.48, =0.001; =-4.21, =0.001). In both groups of models, the distance of the mesial cusp of the left maxillary central incisor was (8.81±2.56) mm, and the distance between mesial buccal cusp of maxillary left first molar was (7.56±2.49) mm, the distance between mesial buccal cusp of maxillary right first molar was (7.13±2.77) mm; the root mean square error was (7.93± 2.94) mm. Compared with 0, the difference was statistically significant (=10.45, <0.001). There were differences between the two methods (anatomical facebow and the jaw movement analyzer) for transferring the maxillary dentition position to the three-dimensional space position of the virtual articulator.
Topics: Male; Female; Humans; Dentition; Dental Occlusion; Incisor; Molar; Dentition, Permanent; Maxilla
PubMed: 38172065
DOI: 10.3760/cma.j.cn112144-20230904-00137 -
Journal of Pharmacy & Bioallied Sciences Feb 2024This research study aimed to evaluate and compare the capability of four various bite registration materials to reproduce precise interocclusal relationships in the...
BACKGROUND
This research study aimed to evaluate and compare the capability of four various bite registration materials to reproduce precise interocclusal relationships in the vertical dimension.
MATERIALS AND METHODS
Ideal maxillary and mandibular casts were mounted on the semi-adjustable articulator in maximum intercuspation after mock tooth preparation on 46, 47, and 48. Models were scanned by the Medit T500 Dental Lab Scanner, and initial reading was noted at the predetermined points. Ten interocclusal bite registrations were made using four materials (CADbite, Jet Bite, Ramitec, and Aluwax). The mandibular model was demounted and again remounted using the interocclusal records, and the final reading was noted after scanning.
RESULTS
Ramitec showed superior results when compared to polyvinyl bite registration material and Aluwax, but the differences between Ramitec, CADbite, and Jet Bite were nonsignificant.
CONCLUSIONS
Although all four materials are suitable for clinical use, elastomeric materials showed superior results. In that, polyether was found to be the best.
PubMed: 38595573
DOI: 10.4103/jpbs.jpbs_990_23 -
The Journal of Prosthetic Dentistry Jan 2024Although average values and facebow records have been incorporated into prosthetic dentistry with much success, little is known about how using 3D facial scans for...
STATEMENT OF PROBLEM
Although average values and facebow records have been incorporated into prosthetic dentistry with much success, little is known about how using 3D facial scans for mounting compare with traditional mounting methods.
PURPOSE
The purpose of this pilot clinical study was to determine differences in measurements among casts mounted virtually by using the average values of the Bonwill triangle and the Balkwill angle, casts mounted by using facebow records, and casts mounted from 3D facial scans.
MATERIAL AND METHODS
Intraoral digital scans were obtained from each participant (n=10) and 3D printed in resin. For the facebow preservation group (FPG), a facebow record was used to mount the resin casts on a semiadjustable articulator. A desktop scanner was used to digitize this mounting while preserving the facebow record. The average mounting group (AMG) consisted of intraoral digital scans that were mounted virtually by using the concepts of the Bonwill triangle and the Balkwill angle. For the facial scan group (FSG), the participants' digitized casts were superimposed on the facial scans by using a target system. The Bergstrom point and the glabella were used to mount these casts and their associated facial scans in the digital environment. This study used the FPG as the group to compare with the other mounting techniques because of its wide acceptance in restorative dentistry. These virtual mountings were completed in a computer-aided design software program, and the distance from right and left condylar elements to the incisal embrasure between mandibular central incisors, distance from left mandibular first molar to left condylar element and from right mandibular first molar to right condylar element, and anterior and posterior recordings at 0 mm, 3 mm, and 5 mm of vertical dimension increase were recorded. A Kruskal-Wallis 1-way analysis of variance was performed (α=.05). The Mann-Whitney U test was performed to evaluate differences in measured values among groups, and multiple comparisons were adjusted by using Bonferroni correction.
RESULTS
All anterior and posterior measurements to the condylar elements of the virtual articulator were found to be significantly different (P<.05). Both anterior and posterior condylar measurements between the FPG and the AMG were found to be significantly different (P<.05), while comparisons between the FPG and the FSG were found not to be significantly different (P>.05). All changes in vertical dimension were found not to be significantly different with respect to both anterior and posterior measurements (P>.05).
CONCLUSIONS
When used to virtually mount dental casts, 3D facial scanners performed similarly to traditional facebow records.
Topics: Humans; Jaw Relation Record; Models, Dental; Face; Computer-Aided Design; Dental Articulators
PubMed: 35382941
DOI: 10.1016/j.prosdent.2022.03.001 -
Journal of Esthetic and Restorative... Jan 2024Complete arch implant rehabilitation necessitates meticulous treatment planning and high-level collaboration between surgical and prosthetic dental teams. Emerging...
OBJECTIVE
Complete arch implant rehabilitation necessitates meticulous treatment planning and high-level collaboration between surgical and prosthetic dental teams. Emerging virtual technologies hold considerable promise in streamlining this process. The aim of this article is to extend recommendations to clinicians venturing into the virtual patient-assisted esthetic implant rehabilitation workflow.
OVERVIEW
This article summarizes recommendations for virtual patient-assisted esthetic implant rehabilitation in the following five aspects: three-dimensional data handling and superimposition, occlusion and virtual articulator integration in creating virtual patients, streamlined face- and prosthetic-driven surgical planning, reuse of presurgical data ("Copy & Paste"), and final impression for passive fitting of final restoration. To illustrate these principles, a case with complete-mouth implant rehabilitation completed within six visits using this virtual patient workflow is presented.
CONCLUSION
The virtual patient workflow serves as an invaluable tool to perform treatment planning, enhance efficiency, and ensure predictable outcomes in esthetic complete arch implant rehabilitation.
CLINICAL SIGNIFICANCE
Virtual workflows are increasingly prevalent in esthetic implant rehabilitation. Nevertheless, these workflows necessitate a distinct set of knowledge and tools divergent from conventional dentistry practices. This article offers guidelines and recommendations for dental clinicians who are new to this field.
Topics: Humans; Computer-Aided Design; Dental Prosthesis, Implant-Supported; Esthetics, Dental; Dental Implants; Workflow
PubMed: 37792734
DOI: 10.1111/jerd.13142 -
The Journal of Prosthetic Dentistry Apr 2024Maxillary and mandibular scans can be articulated in maximum intercuspal position (MIP) by using an artificial intelligence (AI) based program; however, the accuracy of...
STATEMENT OF PROBLEM
Maxillary and mandibular scans can be articulated in maximum intercuspal position (MIP) by using an artificial intelligence (AI) based program; however, the accuracy of the AI-based program locating the MIP relationship is unknown.
PURPOSE
The purpose of the present clinical study was to assess the accuracy of the MIP relationship located by using 4 intraoral scanners (IOSs) and an AI-based program.
MATERIAL AND METHODS
Conventional casts of a participant mounted on an articulator in MIP were digitized (T710). Four groups were created based on the IOS used to record a maxillary and mandibular scan of the participant: TRIOS4, iTero, i700, and PrimeScan. Each pair of nonarticulated scans were duplicated 20 times. Three subgroups were created: IOS, AI-articulated, and AI-IOS-corrected subgroups (n=10). In the IOS-subgroup, 10 duplicated scans were articulated in MIP by using a bilateral occlusal record. In the AI-articulated subgroup, the remaining 10 duplicated scans were articulated in MIP by using an AI-based program (BiteFinder). In the AI-IOS-corrected subgroup, the same AI-based program was used to correct the occlusal collisions of the articulated specimens obtained in the IOS-subgroup. A reverse engineering program (Geomagic Wrap) was used to calculate 36 interlandmark measurements on the digitized articulated casts (control) and each articulated specimen. Two-way ANOVA and pairwise multiple comparison Tukey tests were used to analyze trueness (α=.05). The Levene and pairwise multiple comparison Wilcoxon rank tests were used to analyze precision (α=.05).
RESULTS
Significant trueness discrepancies among the groups (P<.001) and subgroups (P<.001) were found, with a significant interaction group×subgroup (P<.001). The Levene test showed significant precision discrepancies among the groups (P<.001) and subgroups (P=.005). The TRIOS4 and iTero groups obtained better trueness and lower precision than the i700 and PrimeScan systems. Additionally, the AI-articulated subgroup showed worse trueness and precision than the IOS and AI-IOS-corrected subgroups. The AI-based program improved the MIP trueness of the scans articulated by using the iTero and PrimeScan systems but reduced the MIP trueness of the articulated scans obtained by using the TRIOS4 and i700.
CONCLUSIONS
The trueness and precision of the maxillomandibular relationship was impacted by the IOS system and program used to locate the MIP.
PubMed: 38604907
DOI: 10.1016/j.prosdent.2024.03.007 -
Journal of Oral Rehabilitation Mar 2024Occlusal interferences lead to changes in mandibular kinematics to compensate and improve function. However, the effects of different types of eccentric disturbance on... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Occlusal interferences lead to changes in mandibular kinematics to compensate and improve function. However, the effects of different types of eccentric disturbance on the comminution capacity are not known.
OBJECTIVE
To determine the immediate effect of eccentric occlusal interferences on masticatory performance.
METHODS
This crossover clinical trial included 12 healthy dentate subjects aged 25.2 ± 3.3 years who were randomly submitted to seven types of occlusal interference: unilateral and bilateral laterotrusive and mediotrusive, protrusive, dummy and control (no interference). The interference forms were planned in a semi-adjustable articulator, fabricated with composite resin and adhered to the mandibular first molars such that subjects' maximum intercuspation was maintained. Masticatory performance and the chewing rate during 20 cycles were evaluated during subjects' comminution of silicone test food under one interference condition per test day; the multiple sieve method was applied to the comminuted particles. The interference was removed upon test completion, and a 1-week washout period was applied between tests.
RESULTS
Comminuted median particle sizes were larger under unilateral (4.94 ± 0.41 mm) and bilateral (4.81 ± 0.49 mm) laterotrusive, bilateral mediotrusive (4.65 ± 0.50 mm) and protrusive (4.83 ± 0.54 mm) interferences (p < .05) than under the control (4.01 ± 0.52 mm) and dummy (4.18 ± 0.58 mm) conditions (p < .05). Only unilateral and bilateral laterotrusive interferences narrowed the comminuted particle size dispersion (p < .05). The chewing rate did not differ among conditions (p = .1944).
CONCLUSION
Artificial eccentric interferences had an immediate adverse effect on masticatory performance by resulting in larger comminuted particles.
CLINICAL TRIAL REGISTRATION
Brazilian Registry of Clinical Trials (RBR-8g5zfg8).
Topics: Humans; Dental Occlusion; Mandible; Mastication; Molar; Particle Size; Double-Blind Method
PubMed: 37964439
DOI: 10.1111/joor.13620 -
The Journal of Prosthetic Dentistry Jan 2024This clinical report describes a digital workflow for the rehabilitation of an 8-year-old patient diagnosed with ectodermal dysplasia. Based on the patient's digital...
This clinical report describes a digital workflow for the rehabilitation of an 8-year-old patient diagnosed with ectodermal dysplasia. Based on the patient's digital primary casts, small custom trays and an arch tracer were designed and 3-dimensionally printed. The mandibular custom tray and retention plate with a tracing screw were assembled with tracing plate, forming an individual assembled mini-arch tracer system to record the jaw relationship together with a conventional facebow and a digital articulator. In addition, composite resin injection guides were designed and fabricated to form the predesigned targeted shape of the abutment teeth and provide a buffer. By following this workflow, complete overdentures with good fit, occlusion, and acceptable esthetics were delivered.
PubMed: 38199946
DOI: 10.1016/j.prosdent.2023.11.036 -
The Journal of Prosthetic Dentistry Sep 2023This technique report presents a novel method of digitally replicating a treatment denture and converting it into a definitive denture. The procedure accurately...
This technique report presents a novel method of digitally replicating a treatment denture and converting it into a definitive denture. The procedure accurately duplicates the appearance of the mucosal surface and border of the treatment dentures, mounts the jaw relation on a virtual articulator to arrange artificial teeth, and optimizes the occlusion based on recorded mandibular motion tracks. This technique uses personalized jaw relation transfer and dynamic occlusal adjustment to establish balanced occlusion, which accomplishes the digital duplication of the treatment denture with high accuracy and minimal effort.
Topics: Denture, Complete; Occlusal Adjustment; Workflow; Denture Design; Dental Occlusion; Dental Articulators; Jaw Relation Record
PubMed: 34887077
DOI: 10.1016/j.prosdent.2021.09.014