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1.
Chinese Journal of Stomatology ; (12): 414-421, 2023.
Article in Chinese | WPRIM | ID: wpr-986088

ABSTRACT

Objective: To provide a new solution for the digital design of nasal prostheses, this study explores the three-dimensional (3D) facial morphology completion method for external nasal defects based on the non-rigid registration process of 3D face template. Methods: A total of 20 male patients with tooth defect and dentition defect who visited the Department of Prosthodontics, Peking University School and Hospital of Stomatology from June to December 2022 were selected, age 18-45 years old. The original 3D facial data of patients were collected, and the 3D facial data of the external nose defect was constructed in Geomagic Wrap 2021 software. Using the structured 3D face template data constructed in the previous research of the research group, the 3D face template was deformed and registered to the 3D facial data of external nose defect (based on the morphology of non-defective area) by non-rigid registration algorithm (MeshMonk program), and the personalized deformed data of the 3D face template was obtained, as the complemented facial 3D data. Based on the defect boundary of the 3D facial data of the external nose defect, the complemented external nose 3D data can be cut out from the complemented facial 3D data. Then the nasofacial angle and nasolabial angle of the complemented facial 3D data and the original 3D facial data was compared and analyzed, the ratio between the nose length and mid-face height, nose width and medial canthal distance of the complemented facial 3D data was measured, the edge fit between the edge curve of the complemented external nose 3D data and the defect edge curve of the 3D facial data of external nose defect was evaluated, and the morphological difference of the nose between the complemented external nose 3D data and the original 3D facial data was analyzed. Results: There was no significant statistically difference (t=-0.23, P=0.823; Z=-1.72, P=0.086) in the nasofacial angle (28.2°±2.9°, 28.4°±3.5° respectively) and nasolabial angle [95.4°(19.2°), 99.9°(9.5°) respectively] between the 20 original 3D facial data and the complemented facial 3D data. The value of the ratio of nose length to mid-face height in the complemented facial 3D data was 0.63±0.03, and the value of the ratio of nose width to medial canthal distance was 1.07±0.08. The curve deviation (root mean square value) between the edge curve of the complemented external nose 3D data and the defect edge curve of the 3D facial data of external nose defect was (0.37±0.09) mm, the maximum deviation was (1.14±0.32) mm, and the proportion of the curve deviation value within±1 mm was (97±3)%. The distance of corresponding nose landmarks between the complemented facial 3D data and the original 3D facial data were respectively, Nasion: [1.52(1.92)] mm; Pronasale: (3.27±1.21) mm; Subnasale: (1.99±1.09) mm; Right Alare: (2.64±1.34) mm; Left Alare: (2.42± 1.38) mm. Conclusions: The method of 3D facial morphology completion of external nose defect proposed in this study has good feasibility. The constructed complemented external nose 3D data has good facial coordination and edge fit, and the morphology is close to the nose morphology of the original 3D facial data.

2.
Journal of Peking University(Health Sciences) ; (6): 120-123, 2023.
Article in Chinese | WPRIM | ID: wpr-971283

ABSTRACT

OBJECTIVE@#To preliminarily explore the applicable scenarios of an intraoral camera to assist oral anatomical landmarks recognition, so as to improve the clinical diagnosis and treatment mode, cultivate the concept of caring for patients, strengthen doctor-patient communication, assist experts to teach, and improve the clinical diagnosis and efficacy rate.@*METHODS@#A new type of an intraoral camera was applied in the recognition of oral anatomy landmarks and four application scenarios were developed, namely: (1) clinical diagnosis and treatment scenarios, in which doctors used intraoral camera to conduct a comprehensive examination of patients in the mouth and take videos and photos; (2) doctor-patient communication scenarios, when the doctor told the patient about the treatment plan, the video or photo taken by the intraoral camera was displayed to the patient; (3) expert teaching scenarios, when the expert used an intraoral camera to teach in the patient's mouth, and the young doctor learned oral anatomical signs on the projection screen, with the study of theoretical lessons; (4) difficult case recording scenarios, in the process of clinical diagnosis and treatment, when encountering difficult cases, you could use intraoral camera to record and take photos for young doctors to discuss, and experts to comment and guide.@*RESULTS@#The application of intraoral camera could: (1) improve the clinical diagnosis and treatment mode and raise the clinical diagnosis and efficacy rate; (2) stimulate young doctors' interest in learning, use intraoral camera in assessments, and skillfully combine theoretical knowledge of anatomical landmarks with clinical practice, so as to improve the teaching effect; (3) cultivate, through self or mutual use, the concept of caring for patients and reinforce the importance of gentle operation; (4) strengthen doctor-patient communication. Doctors could communicate with patients more visually, so that the patients could better understand their own situation, and strengthen the patients' trust in the doctors.@*CONCLUSION@#Intraoral camera can assist oral clinical diagnosis and treatment, such as the recognition of oral anatomical landmarks. It plays a certain role in promoting the improvement of clinical diagnosis and treatment mode, stimulating learning interest, cultivating the concept of caring for patients, and enhancing doctor-patient communication.


Subject(s)
Humans , Physician-Patient Relations , Physicians , Communication , Mouth , Learning
3.
Journal of Peking University(Health Sciences) ; (6): 108-113, 2023.
Article in Chinese | WPRIM | ID: wpr-971281

ABSTRACT

OBJECTIVE@#To predict the learning curve of tooth preparation for all ceramic crowns of maxillary central incisors on phantom head simulators for graduate students participating in standardized dental resident training based on the modified Wright learning curve model, then to analyze and applicate the learning curve.@*METHODS@#Twelve graduate students participating in standardized dental resident training were selected to prepare the resin maxillary central incisors on phantom head simulators for all ceramic crowns 4 times. The results of preparation were evaluated by 3 prosthetic experts with at least 10 years' experience focusing on the reduction, contour, taper, shoulder, finish line, margin placement, adjacent tooth injury, and preparation time for tooth preparation. The learning rate of tooth preparation was calculated by scores of tooth preparation of 4 times. The learning curve of tooth preparation was predicted based on the modified Wright learning curve model. According to the criteria of standardized training skill examinations for dental residents in Beijing, 80 was taken as the qualified standard score. The minimum training times for tooth preparation to satisfy the qualified standard score (80) was calculated, to analyze the characteristics of learning curve and evaluate the effectiveness of tooth preparation.@*RESULTS@#The scores of 4 tooth preparation were 64.03±7.80, 71.40±6.13, 74.33±5.96, and 75.98±4.52, respectively. The learning rate was (106±4)%, which showed the learning curve an upward trend. There were no significant differences between the qualified standard score and the predicted scores of tooth preparation from the 5th preparation to the 13th preparation (P > 0.05). The predicted score of the 14th preparation was higher than the qualified standard score (P < 0.05).@*CONCLUSION@#The trend of the learning curve of tooth preparation for all ceramic crowns of maxillary central incisors on phantom head simulators for graduate students participating in standardized dental resident training is upward, which predicts the minimum training times higher than the qualified standard score is 14 times.


Subject(s)
Humans , Tooth Preparation, Prosthodontic/methods , Incisor , Learning Curve , Crowns , Tooth Preparation , Ceramics , Dental Porcelain , Dental Prosthesis Design
4.
Chinese Journal of Stomatology ; (12): 101-106, 2022.
Article in Chinese | WPRIM | ID: wpr-935836

ABSTRACT

In dental esthetic rehabilitation, patients pay great attention to the rehabilitative esthetic effect before teeth preparation, and this is also an important content of doctor-patient communication. Along with the development and combined application of intraoral scan, three-dimensional (3D) face scan, digital design, numerical control machining and 3D printing technology, digital technology is gradually applied to the virtual simulated design before irreversible operation in dental esthetic rehabilitation. Digital technology can be used in dentistry to simulate the esthetic outcome in advance, to assist communication among the dentists, patients and dental technicians, and to realize satisfactory outcome in the final restorations precisely, which, as a result, increases the clinical satisfaction. This review focuses on the application of digital virtual simulated design technology in dental esthetic rehabilitation, analyzes the current research development, deficiency and future prospects, so as to provide guidance for clinical diagnosis and treatment.


Subject(s)
Humans , Computer-Aided Design , Esthetics, Dental , Face , Printing, Three-Dimensional , Tooth Preparation
5.
Journal of Peking University(Health Sciences) ; (6): 193-199, 2022.
Article in Chinese | WPRIM | ID: wpr-936134

ABSTRACT

OBJECTIVE@#To automatically construct lips symmetry reference plane (SRP) based on posed smile, and to evaluate its advantages over conventional digital aesthetic design.@*METHODS@#Eighteen subjects' three-dimensional facial and dentition data were gathered in this study. The lips SRP of experimental groups were used with the standard weighted Procrustes analysis (WPA) algorithm and iterative closest point (ICP), respectively. A reference plane defined by experts based on regional ICP algorithm, served as the truth plane. The angle error values between the lips SRP of WPA algorithm in the experimental groups and the truth plane were evaluated in this study, and the lips SRP of ICP algorithm of the experimental groups was calculated in the same way. The lips SRP based on posed smile as a reference for aesthetic design and evaluate preliminary clinical application.@*RESULTS@#The average angle error between the lips SRP of WPA algorithm and the truth plane was 1.78°±1.24°, which was smaller than that between the lips SRP of ICP and the truth plane 7.41°±4.31°. There were significant differences in the angle errors among the groups (P < 0.05). In the aesthetic design of anterior teeth, automatically constructing the lips SRP of WPA algorithm based on posed smile and the original symmetry plane by re-ference compared with the prosthetic design, the subjects' scores on the lips SRP of WPA algorithm based on posed smile (8.48±0.57) were higher than those on the original symmetry plane (5.20±1.31).@*CONCLUSION@#Automatically constructing the lips SRP of WPA algorithm based on posed smile was more accurate than ICP algorithm, which was consistent with the truth plane. Moreover, it can provide an important reference for oral aesthetic diagnosis and aesthetic analysis of the restoration effect. In the aesthetic design of anterior teeth, automatically constructing the lips SRP of WPA algorithm based on posed smile can improve the patients' satisfaction in esthetic rehabilitation.


Subject(s)
Humans , Esthetics, Dental , Lip , Smiling , Tooth , Workflow
6.
Journal of Peking University(Health Sciences) ; (6): 406-412, 2021.
Article in Chinese | WPRIM | ID: wpr-942195

ABSTRACT

OBJECTIVE@#To compare the differences and indications of three evaluation methods for fitness evaluation of removable partial denture (RPD).@*METHODS@#A RPD was fabricated and seated on the stone cast of a partially edentulous mandible, and the spaces between RPD and stone cast were recorded with polyvinyl siloxane (PVS) impression material forming PVS replicas. Using cross sectional measurement, the average thicknesses of PVS replicas were measured under stereomicroscope with different numbers of selected measuring points in the denture base, major connector, occlusal rest of the RPD, and the average thicknesses of the PVS replicas measured with different numbers of measuring points were compared using one-way analysis of variance (ANOVA) and independent sample t test. Three kinds of method, including cross sectional measurement, three-dimensional analysis on the stone cast, and three-dimensional analysis on the polyether cast, were applied to measure the average thicknesses of the PVS replicas, and the average thicknesses of the PVS replicas measured by these three evaluation methods were compared with ANOVA.@*RESULTS@#For cross sectional measurement, statistically significant differences were found in the average thicknesses of the PVS replicas in the denture base and the major connector among the different numbers of measuring points (P < 0.05), but no differences were found in the average thicknesses of the PVS replicas in the occlusal rest (P>0.05). There were significant differences among the average thicknesses of the PVS replicas measured by these three evaluation methods in each component of the RPD (P < 0.01). The average thickness measured by three-dimensional analysis on the stone cast and three-dimensional analysis on polyether cast were smaller than that measured by cross sectional measurement (P < 0.05). And there were no differences between the average thicknesses of PVS replicas measured by three-dimensional analysis on stone cast and three-dimensional analysis on polyether cast (P>0.05).@*CONCLUSION@#For cross sectional measurement, the average thickness of the PVS replicas was influenced by the number of measuring points, and the measurement accuracy of cross sectional measurement was not reliable enough. Three-dimensional analysis on stone cast which is suitable for evaluation in vitro and three-dimensional analysis on polyether cast which is suitable for evaluation in vivo can evaluate the fitness of RPD more comprehensively and effectively than that of cross sectional measurement.


Subject(s)
Computer-Aided Design , Cross-Sectional Studies , Denture, Partial, Removable , Exercise , Research Design
7.
Journal of Peking University(Health Sciences) ; (6): 402-405, 2021.
Article in Chinese | WPRIM | ID: wpr-942194

ABSTRACT

OBJECTIVE@#To evaluate the effects of different edge compensation angles on the fracture strength of multilayer zirconia all-ceramic crowns and traditional uniform zirconia all-ceramic crowns.@*METHODS@#The resin tooth preparation specimen of the mandibular first molar with a knife-edge was fabricated. A 3D digital model of the specimen was obtained by scanning it with a 3D dental model scanner. The 3D digital model was imported into computer aided design (CAD) software, and three 3D digital models of the full crown with the same surface shape are designed with the edge compensation angles of 30°, 45° and 60°, respectively. Then, the designed 3D digital model is imported into computer aided manufacturing (CAM) software. Three kinds of multilayer and homogeneous zirconia all-porcelain crowns with different edge compensation angles were fabricated, 10 each for a total of 60. The fracture load of each crown was measured under the electronic universal testing machine.@*RESULTS@#Fracture load of multilayer and uniform zirconia all-ceramic crowns, (4 322.86±610.07) N and (5 914.12±596.80) N in the 30° group, (5 264.82±883.76) N and (5 220.83±563.38) N in the 45° group and (4 900.42±345.41) N and (5 050.22±560.24) N in the 60° group, respectively. The fracture load of multi-layer zirconia all-ceramic crowns in the 30° group was significantly lower than that of homogeneous zirconia all-ceramic crowns(P < 0.05); there was no statistical significance in 45° group and 60° group(P>0.05). In the multi-layer zirconia all-ceramic crowns: the fracture load of the 30° group was significantly lower than that of the 45° group (P < 0.05); there was no significant difference between the 30° group and the 60° group, the 45° group and the 60° group (P>0.05).In uniform zirconia full crown group: the 30° group was higher than the 45° group, the 30° group was higher than the 60° group (P < 0.05), and there was no significant difference between the 45° group and the 60° group (P>0.05).@*CONCLUSION@#The fracture loads of three kinds of uniform and multilayer zirconia all ceramic crowns with different edge compensation angles can meet the clinical requirements. A smaller edge compensation angle is recommended when using traditional zirconia all-ceramic crowns, while 45° is recommended when using multi-layer zirconia all-ceramic crowns.


Subject(s)
Ceramics , Computer-Aided Design , Crowns , Dental Porcelain , Dental Prosthesis Design , Dental Restoration Failure , Dental Stress Analysis , Flexural Strength , Materials Testing , Zirconium
8.
Journal of Peking University(Health Sciences) ; (6): 62-68, 2020.
Article in Chinese | WPRIM | ID: wpr-942142

ABSTRACT

OBJECTIVE@#To explore the preliminary application of "biocopy function" in digital technology of temporary crown in severe tooth attrition, so as to reduce the difficulty of final restoration adjustment in severe tooth wear cases, and save clinical time.@*METHODS@#Twelve patients aged between 40 and 65 years with severe tooth attrition were recruited in this study. The experimental group (6 cases, 3 females and 3 males) used the method of digital copy of temporary restoration shape when making the final restoration, and the control group (6 cases, 3 females and 3 males) used the traditional method to make the final restoration. The mean time of central occlusal adjustment and protrusive and lateral occlusal adjustment of each crown, the number of follow-up visits of the patients were recorded and statistically analyzed. The occlusal comfort of the first and the third months after wearing the prosthesis was evaluated by the patients, and the difference of the occlusal comfort of the final prosthesis made by the two methods was compared (the full score was 10 points). The occlusal adjustment time and occlusal comfort score were used as measurement data. Single sample t test was used. The number of follow-up visits was count data. Rank sum test was used for non-normal continuous variables.@*RESULTS@#The mean occlusal time of each crown adjustment in the experimental group was significantly lower than that in the control group (P < 0.01), and the median number of follow-up visits in the experimental group was lower than that in the control group (P < 0.01). The average occlusal comfort score of the experimental group was higher than that of the control group at the first time (P < 0.01). After three months of crown wearing, the median occlusal comfort score of the experimental group was higher than that of the control group (P < 0.05).@*CONCLUSION@#In the case of severe tooth attrition, it is feasible to use the "biocopy function" in the design software to design the final prosthesis, which is conducive to reduce the difficulty of adjustment and achieve predictable functional and aesthetic effects, which is of great significance to save clinical time and improve the accuracy of restoration.


Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Computer-Aided Design , Crowns , Tooth
9.
Journal of Peking University(Health Sciences) ; (6): 390-394, 2020.
Article in Chinese | WPRIM | ID: wpr-942017

ABSTRACT

Fabrication of conventional complete dentures involves a complex restoration method, requiring significant time and typically involving primary impressions, definitive impressions, jaw relation records, clinic try-in, and complete denture placement, which has been used for nearly a century without change. A novel digital system named Functionally Suitable Denture (FSD) was researched and developed so as to reduce clinical steps, operation difficulties and errors of complete denture restoration. It pioneered a unique diagnostic complete denture aided by computer aided design (CAD) & 3D printing, by which, the functional impression, jaw relation, and try-in (3 steps) were simplified to 1 step, thus the number of visits to the dentist was reduced by 2 times. Moreover, for the first time, it put forward a CAD software of template matching based on the expert design, which was an efficient and intelligent design scheme, and the excellent denture experts' experience and skills could be inherited and iterated. The system included the 3D scanner with appropriate accuracy and high efficiency, the CAD software, the special 3D printer and process software, and the innovative clinical operation process. The Patent Cooperation Treaty (PCT) patent international search report showed that all the 15 claims of the technology were of novelty, creativity and industrial utility. All the digital products were independently developed and made by Peking University School and Hospital of Stomatology, China. The design and manufacture process of denture prosthesis was fast, simple and accurate. At the same time, personalized functional and aesthetic matching of the patients after wearing prosthesis was realized. It effectively solved the global problems of "slow, difficult and inaccurate" of the traditional manual technology of complete denture, and brought good news to edentulous patients. Compared with the traditional complete denture treatment, FSD system has a wide range of applications for different types of edentulous patients, including those with severe resorption of the alveolar ridge or a high occlusal force. Furthermore, the low-cost of 3D printers, compared with expensive milling machines, may make the approach more accessible. This review describes that our research is related to the development of the FSD system, including multi-source data acquisition technology, three generations of complete denture design software, 3D printing systems of individual tray and complete denture pattern, the clinical and laboratory operation process of the FSD system.


Subject(s)
Humans , China , Computer-Aided Design , Creativity , Denture, Complete , Mouth, Edentulous
10.
Journal of Peking University(Health Sciences) ; (6): 187-192, 2020.
Article in Chinese | WPRIM | ID: wpr-941987

ABSTRACT

OBJECTIVE@#To explore the possibility of the Smile Lite MDP (Smile Lite Mobile Dental Photograph) portable dental photography system applying in anterior teeth aesthetic photography, and to provide the chance to simplify aesthetic photography process and facilitate communication among patients, dentists and dental technitians.@*METHODS@#The Smile Lite MDP photography system combined with the smartphone were used to photograph the front occlusal phase photos of anterior teeth. The photographic conditions including the color temperature parameter, the Smile Lite MDP light position and the intensity settings were explored. The best photographic conditions were chosen by blind evaluation within experienced dentists and technicians through the method of the visual analogue scale/score (VAS) evaluation, which went through statistical analysis to figure out the optimum photograghic conditions. Smile Lite MDP photography system was used to photograph the front occlusal phase photos of anterior teeth under the optimum parameter by different magnifications. The width/height ratio of the central incisor and the front width ratio of the upper anterior teeth in those photos were measured and calculated respectively. The accuracy of the anterior teeth photos taken by Smile Lite MDP photography system was analyzed based on the photographs taken by digital single lens reflex (DSLR) camera.@*RESULTS@#The optimum color temperature parameter of Smile Lite MDP portable camera system was 5 000 K, the optimum magnification was 4 times, the best light position was the side lights of Smile Lite MDP, the optimum intensity of lights was 2 grades. Photos taken by the optimum parameters won the highest score during the VAS evaluation and the result of statistical analysis had significant difference compared with other groups (P<0.05). When comparing the photos of the upper anterior teeth taken by the Smile Lite MDP portable photography system using 4 times magnification or by DSLR using the standard parameters, there was no significant difference neither in the width/hieght ratio of the central incisor nor in the front width ratio of the upper anterior teeth (P>0.05).@*CONCLUSION@#The Smile Lite MDP portable dental photography system applying in anterior teeth aesthetic analysis photography was capable to show the color and shape of anterior teeth in an accurate way by using the right photography parameters. Therefore, Smile Lite MDP portable dental photography system was considered to be a simple and easy photographic tool in clinical work.


Subject(s)
Humans , Esthetics , Esthetics, Dental , Incisor , Photography , Smiling
11.
Journal of Peking University(Health Sciences) ; (6): 349-355, 2019.
Article in Chinese | WPRIM | ID: wpr-941819

ABSTRACT

OBJECTIVE@#To design and fabricate edentulous custom trays by chair-side computer-aided design and 3-dimensional printing (CAD/3DP) system of independent research and development and to evaluate their clinical effects based on prosthodontists'satisfaction using the visual analogue scale (VAS).@*METHODS@#Fifteen edentulous patients were randomly recruited by three prosthodontists who passed the unified operating process training. The custom trays for each patient were fabricated using both chair-side CAD/3DP system of independent development and manually conventional method, and the final impressions were made by silicone impression materials (light body). The prosthodontist's satisfaction was surveyed by the three prosthodontists via the questionnaire based on visual analogue scales.@*RESULTS@#In the degree of the prosthodontist's satisfaction of final impressions, the average satisfactions of "try in" (the overall size, shape, convenience, etc.) on the 3DP custom tray made by independent development chair-side system and the manually conventional method were 9.18±0.19 and 8.23±0.22, respectively. The average satisfactions of the border line position (border extensions, frenal notch)were 8.91±0.40 and 7.96±0.23, respectively. The average satisfactions of the stability in border molding were 8.80±0.83 and 8.01±0.81, respectively. The average satisfactions of the quality of final impression (completeness, thickness of impression material, exposure of custom tray, shape of border) were 8.94±0.68 and 7.99±0.42, respectively. The average satisfactions of the difficulty of high quality impression (times of repetition, efficiency) were 9.20±0.37 and 7.88±0.22, respectively. The average satisfactions of the overall satisfaction were 9.11±0.49 and 7.95±0.15, respectively. There was significant difference in the satisfaction of "try in", border line position, stability in border molding, quality of final impression, difficulty of high quality impression, and overall satisfaction between the 3DP custom tray made by chair-side system of independent development and the manually conventional method (P<0.05).@*CONCLUSION@#In the degree of the prosthodontist's satisfaction of final impression, the 3DP custom tray made by chair-side system of independent development is higher than that of the conventional custom tray, and it meets the clinical requirements and can be popularized in clinical application.


Subject(s)
Humans , Computer-Aided Design , Dental Impression Materials , Dental Impression Technique , Mouth, Edentulous , Printing, Three-Dimensional
12.
Journal of Peking University(Health Sciences) ; (6): 335-339, 2019.
Article in Chinese | WPRIM | ID: wpr-941816

ABSTRACT

OBJECTIVE@#To explore a novel method for fabricating removable partial dentures (RPDs) using polyetheretherketone (PEEK) by computer-aided design and computer-aided manufacturing (CAD/CAM) technologies and to evaluate their fits for different assemblies in vitro.@*METHODS@#A standard stone cast of mandibular partial edentulous jaw was scanned using a lab scanner. Based on the digital cast, thirteen complete RPDs were designed combing dental CAD software and reverse engineering software, and then fabricated using PEEK by milling machine. Fits of assemblies were evaluated quantitatively by measuring the spaces between RPDs and casts. The gaps between RPDs and stone casts in different assemblies were duplicated using light-body silicone impression material and then measured using three-dimensional (3D) digital analysis methods in virtue of a dedicated software. Statistically, one-way analysis of variance (ANOVA) was used to compare the difference of gaps among assemblies in different shapes such as occlusal rest, denture base, and major connector. Paired-samples t test was used to compare the gaps difference for the similar shape assemblies in different areas.@*RESULTS@#One-piece PEEK RPDs were successfully designed and fabricated by CAD/CAM, and all the RPDs were well-seated on stone casts. The gaps between occlusal rests and casts [(84.3±23.6) μm] were significantly larger than those of denture bases [(32.5±27.8) μm] and major connectors [(49.9±47.0) μm], which meant that the fits of denture bases and major connectors were better than that of occlusal rests. However, the fits of all assemblies could be accepted clinically. For the similar shape assemblies in different areas, there were no significantly differences for gaps between distal extension denture bases [(25.1±55.3) μm] and non-extensive denture bases [(41.5±17.7) μm]. The gaps of occlusal rests adjacent and nonadjacent to the edentulous space were (86.1±29.8) μm and (80.8±42.1) μm respectively and there were no significantly difference between them either. These results implied that different locations had no apparent effect on the fits of assemblies.@*CONCLUSION@#With the computer-aided design and computer-aided manufacturing technology, PEEK can be used to fabricate one-piece removable partial dentures. And all assemblies of the one-piece PEEK RPDs showed satisfying fits in vitro, indicating a promising clinical application in the future.


Subject(s)
Benzophenones , Computer-Aided Design , Denture, Partial, Removable , Ketones , Polyethylene Glycols , Polymers
13.
Journal of Peking University(Health Sciences) ; (6): 105-110, 2019.
Article in Chinese | WPRIM | ID: wpr-941778

ABSTRACT

OBJECTIVE@#To establish a complete workflow of digital design and manufacturing occlusal splint for sleep bruxism, which can be preliminarily applied in clinical use, thus observe the clinical efficacy.@*METHODS@#Twenty-four patients with sleep bruxism were recruited in the study and randomly divided into two groups by using random number tables. Digital-occlusal-splint (experimental group) treatment plan and traditional-occlusal-splint (control-group) treatment plan were carried out for each group, respectively. For experimental group, digital models of patients' both dental arches and the occlusion relationship after elevation were captured using an intraoral scanner. The occlusal splint was carried out by computer aided design/computer aided manufacturing (CAD/CAM), including splint designing and milling. For control group, the traditional soft occlusal splint was fabricated by vacuum laminator. The two kinds of occlusal splints were tried in the patients from each group, and the occlusal contacts were tested respectively by T-scan analysis system, which recorded the changes of occlusal indicators in the two groups. The retention, appearance and occlusal comfort degree were evaluated by the two groups of patients. Mann-Whitney test was performed with IBM SPSS 20.0 software, and bilateral test was performed. P<0.05 was considered to be statistically significant.@*RESULTS@#The complete workflow of digital design and manufacturing occlusal splint was successfully established. During the clinical use, there was no statistical difference in the retention evaluation of two kinds of occlusal splints between the two groups of patients (Z=-0.538, P=0.590). The appearance score (Z=2.038, P=0.042) and the occlusal comfort score (Z=-2.579, P=0.010) of the experimental group were higher than those of the control group, with statistically significant differences. The T-scan analysis results showed that only the second molar on both sides of the traditional occlusal splint had occlusal contact in intercupsal position, while the digital occlusal splint had stable and bilaterally balanced contact between the maxillary and mandibular teeth. Furthermore, the occlusal force was uniformly distributed in the experimental group.@*CONCLUSION@#The complete workflow of digital occlusal splint improves the occlusal design, greatly simplifies and optimizes the traditional process of making occlusal splint. This new method is resource-saving and environmental-friendly, and it is able to serve patients more conveniently and efficiently.


Subject(s)
Humans , Dental Arch , Dental Occlusion , Occlusal Splints , Sleep Bruxism , Workflow
14.
Journal of Peking University(Health Sciences) ; (6): 78-84, 2018.
Article in Chinese | WPRIM | ID: wpr-691463

ABSTRACT

OBJECTIVE@#To develop a digital workflow of orthodontic-prosthodontic multidisciplinary treatment plan which can be applied in complicated anterior teeth esthetic rehabilitation, in order to enhance the efficiency of communication between dentists and patients, and improve the predictability of treatment outcome.@*METHODS@#Twenty patients with the potential needs of orthodontic-prosthodontic multidisciplinary treatment to solve their complicated esthetic problems in anterior teeth were recruited in this study. Digital models of patients' both dental arches and soft tissues were captured using intra oral scanner. Direct prosthodontic (DP) treatment plan and orthodontic-prosthodontic (OP) treatment plan were carried out for each patient. For DP treatment plans, digital wax-up models were directly designed on original digital models using prosthodontic design system. For OP treatment plans, virtual-setups were performed using orthodontic analyze system according to orthodontic and esthetic criteria and imported to prosthodontic design system to finalize the digital wax-up models. These two treatment plans were shown to the patients and demonstrated elaborately. Each patient rated two treatment plans using visual analogue scales and the medians of scores of two treatment plans were analyzed using signed Wilcoxon test. Having taken into consideration various related factors, including time, costs of treatment, each patient chose a specific treatment plan. For the patients chose DP treatment plans, digital wax-up models were exported and printed into resin diagnostic models which would be utilized in the prosthodontic treatment process. For the patients chose OP treatment plans, virtual-setups were used to fabricate aligners or indirect bonding templates and digital wax-up models were also exported and printed into resin diagnostic models for prosthodontic treatment after orthodontic treatment completed.@*RESULTS@#The medians of scores of DP treatment plan and OP treatment plan were calculated and analyzed by IBM SPSS 20. The median of scores of DP treatment plan was 8.4, the minimum value was 6.9 and the maximum value was 9.3. The median of scores of OP treatment plan was 9.0, the minimum value was 7.9 and the maximum value was 9.6. The median of scores of OP was significantly higher than that of DP (Z=-3.23, P<0.01). Finally, 12 patients chose OP treatment plans and 8 patients chose DP treatment plans.@*CONCLUSION@#For cases with complex esthetic problems in anterior teeth, a digital workflow can demonstrate final treatment outcome and help patients make suitable treatment decisions. In our study, the orthodontic-prosthodontic multidisciplinary treatment plan is feasible which can provide predictions of treatment outcome and improve esthetic outcome with patients' satisfaction.


Subject(s)
Humans , Dental Arch , Esthetics, Dental , Prosthodontics , Tooth
15.
International Journal of Oral Science ; (4): 114-118, 2012.
Article in English | WPRIM | ID: wpr-269641

ABSTRACT

The presence of a large palatal or maxillary defect after partial or total maxillectomy for tumor, trauma or congenital deformation poses a challenge to prosthodontists, particularly when the use of an implant cannot be considered. This case report described the use of an air valve in a hollow silicone obturator to manufacture an inflatable obturator that could be extended further into undercut area to retain itself. The inflatable obturator exhibited adequate retention, stability and border sealing, thereby improving the masticatory,pronunciation and swallowing functions of patients. It may be a suitable alternative treatment option to an implant-retained obturator.


Subject(s)
Humans , Male , Young Adult , Dental Impression Technique , Dental Prosthesis Design , Dental Prosthesis Retention , Denture Retention , Denture, Complete, Upper , Fibrous Dysplasia of Bone , Rehabilitation , General Surgery , Maxilla , General Surgery , Orthognathic Surgical Procedures , Methods , Rehabilitation , Palatal Obturators , Silicones , Treatment Outcome
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