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Objective@#To explore an accurate method to obtain an intraoral model of patients with specific limited mouth opening (microstomia) due to systemic scleroderma.@*Methods@#This study followed medical ethics, and informed consent has been obtained from patients. A case of Ken's Type I mandibular dentition defect scleroderma with limited mouth opening was addressed with digital technology as the leading method combined with the traditional impression method of segmental impression. Individual trays were made based on the patient's left and right mandibular dentition, and segmented molds were obtained. Simultaneously, intraoral scanning was performed to obtain the morphological data of both the soft and hard tissues of the upper and lower mandibles. After each part of the model was obtained, the mandibular model was scanned and digitally aligned to form the final denture model, and the final removable partial denture was designed and made by computer aided design/computer aided manufacturing (CAD/CAM) technology. At the same time, combined with the literature, the diagnosis and treatment of removable partial denture in patients with limited mouth opening were retrospectively analyzed.@*Results@#The denture was well retained and achieved a good repair effect. The patients expressed satisfaction with the mastication efficiency and other functions of the denture. The findings of the literature review show that the integration of digital technology with the traditional impression method, along with computer fitting, can accurately obtain the patient's oral model and facilitate successful follow-up repairs. However, when the anterior mandibular dentition of the patient is absent, the margin of error is increased in this procedure, which deserves further exploration.@*Conclusion@#Utilizing digital technology as the leading method, combined with the traditional impression method of segmental impression, for the repair of dental defects in patients with limited mouth opening, has proven to be effective. Thus, patients report a positive medical experience with high satisfaction, indicating that this approach is worthy of clinical promotion.
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@#Due to advances in digital technology, intraoral impressions have been increasingly used to fabricate implant restorations because of its simplicity, high efficiency, comfortableness and convenience. In clinical practice, the accuracy of intraoral impressions depends on various factors, including scanner technique, status of dentition and implants, auxiliary devices, materials and environment, which might influence its accuracy and limit its application. When applied to patients missing more teeth, its accuracy may be insufficient. It is suggested that intraoral impressions be used cautiously when there are multiple and far apart implants and that the scan body not be tightened excessively and that maintain appropriate environmental conditions. In this article, we have reviewed recent relevant literature and the factors affecting the accuracy of intraoral impressions for implant restoration.
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Objective @# To compare the tooth drift differences between different types of patients after orthodontic extraction for 1.5 months (45 days) without return to the clinic on time for some reasons.@*Methods@#This study has been reviewed and approved by the Ethics Committee, and informed consent has been obtained from patients. A total of 84 patients had bilateral premolars extracted but were not bonded the bracket for some reasons. The upper and lower jaw dental models were cast, scanned, and reconstructed in 3D. Patients were divided into 12 groups based on extraction positions (first premolar or second premolar), jaw types (maxilla or mandible) and vertical facial types (average angle, high angle, or low angle). Multivariate analysis of variance was used to analyze the changes in the following five indicators in different types of patients who were interrupted for 1.5 months after extraction: anterior tooth crowding, width between canines, width between first molars, tooth extraction space, and overbite of anterior teeth. @*Results @#The tooth extraction position, jaw type and vertical facial type had an effect on the reduction in tooth extraction space and anterior tooth crowding before and after the sudden emergent state (1.5 months after tooth extraction) (P<0.001), and the tooth extraction position and vertical facial type had an effect on the increase in anterior tooth overbite (P<0.001). The drift of bilateral adjacent teeth was greater in patients with first premolars extracted than in those with second premolars extracted (P<0.001), and the drift of bilateral adjacent teeth in the maxilla was larger than that of the mandible (P<0.001). The drift of bilateral adjacent teeth in patients with high angles was more obvious than that of patients with average angles and low angles (P<0.001). @* Conclusion@# For orthodontic patients who have maxillary tooth extraction, first premolar extraction, and even high angles in the vertical facial type, the bilateral adjacent teeth are easier to drift, orthodontic treatment should be carried out soon after extraction, and attention should be given to anchorage control.
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O objetivo deste estudo laboratorial foi avaliar a acurácia dos modelos digitais obtidos por duas técnicas de escaneamento (escâner intraoral - Itero 5d Element® - e escâner de bancada -Straumann ®) de um modelo experimental (Nacional Ossos ®) da arcada superior confeccionada em poliuretano e do modelo de gesso obtido desta arcada. Os pontos A 3mm acima do elemento 17; B 3mm acima do elemento 14; C 3mm acima do elemento 24; D 3mm acima do elemento 27; E cúspide mesiovestibular do elemento 16; F - ponto de contato mais incisal entre os elementos 11 e 21; G - Cúspide mesiovestibular do elemento 26 foram utilizados como referência para as medidas realizadas. As medidas foram realizadas em um software (Geomagic®) de simulação cirúrgica e analisadas quanto a validade e precisão das técnicas de escaneamento utilizadas em todos os grupos (1 a 5). O grupo 1 corresponde ao grupo padrão-ouro; o 2 ao grupo do escaneamento com escâner intraoral do modelo de poliuretano; o 3 ao escaneamento de bancada do modelo; o 4 ao escaneamento com escâner intraoral do modelo de gesso; e 5 ao escaneamento de bancada do modelo de gesso. Na análise da validação, todas as técnicas apresentaram-se válidas quando comparadas ao grupo controle com exceção da medida FG que apresentou diferenças estatisticamente significativas (p<0,05) entre os grupos 1 e 2. A precisão foi avaliada através do índice de correlação intraclasse (CCI) e todas as técnicas apresentaram-se altamente precisas com (CCI) próximo de 1. Desta forma, conclui-se que o escâner intraoral e o escâner de bancada utilizados neste estudo foram confiáveis quando comparados ao grupo controle e que os dois modelos de escâner utilizados se apresentaram com alta precisão (AU).
The objective of this experimental study was to evaluate the accuracy of digital models generated by two scanning techniques (intraoral scanner - Itero 5d Element® - and desktop scanner -Straumann ®) of an experimental model of the upper arch (Nacional Ossos ®) made of polyurethane and the plaster model obtained from this arch. Points A 3mm above element 17; B 3mm above element 14; C 3mm above element 24; D 3mm above element 27; E mesiobuccal cusp of element 16; F - most incisal point of contact between elements 11 and 21; G - Mesiobuccal cusp of element 26 were used as a reference for the measurements performed. The measurements were performed in a surgical simulation software (Geomagic ®) and analyzed for the validity and precision of the scanning techniques used in all groups (1 to 5). Group 1 corresponds to the gold standard group; 2 to the scanning group with intraoral scanner of the polyurethane model; 3 to the desktop scan of the model; 4 to intraoral scanner scanning of the plaster model; and 5 to the desktop scan of the plaster model. In the validation analysis, all techniques showed to be valid compared to the control group, except the FG measure, which showed statistically significant differences (p<0.05) between groups 1 and 2. Precision was assessed using the intraclass correlation(ICC) index, and all techniques were highly accurate with an ICC close to 1. Thus, it is concluded that the intraoral scanner and the bench scanner used in this study were reliable compared to the control group and that the two scanner models used presented themselves with high precision (AU).
Subject(s)
Imaging, Three-Dimensional/instrumentation , Models, Dental/trends , Orthognathic Surgery , Dimensional Measurement Accuracy , Statistics, Nonparametric , Clinical Laboratory TechniquesABSTRACT
Objective@#To explore the application effect of a four-dimensional smile design as the leading and facial streamline as the reference system in the aesthetic restoration of anterior teeth.@*Methods@# A case of scattered space in anterior teeth was treated with a four-dimensional smile design and digital aesthetic restoration with ultrathin porcelain veneer. The digital information of the patients was obtained through oral and facial scanning, and a four-dimensional smile design and prediction were carried out. After the treatment plan was jointly determined by doctors and patients, minimally invasive abutment preparation was carried out, and ultrathin porcelain veneer was made and bonded in place. After the operation, the esthetic degree and marginal fit were observed and reexamined one year after the repair.@* Results @#The edges of the ultrathin ceramic veneers were naturally tight, and the color was coordinated, with satisfying pink and white esthetics. The face was more harmonious and natural when smiling. One year after the restoration, the facial aesthetics were wonderful, the abutment teeth and periodontal tissues were healthy, and the patients were satisfied. The results of the literature review showed that the fitting of temporal facial scanning and intraoral scanning data can accurately predict four-dimensional smile aesthetics, simulate the real state of the dynamic smile and pronunciation process, and combine it with facial streamlines to design a natural and coordinated personalized smile for patients with asymmetric faces. However, for patients with occlusal changes, unstable occlusion or temporomandibular joint disorder, it is necessary to add data fitting, such as electronic facial arch and cone beam CT, to more accurately simulate postoperative mandibular movement.@*Conclusion@# With a four-dimensional smile design as the leading and facial streamline as the reference system, the whole process digital design assisted the restoration of asymmetric anterior teeth with ultrathin porcelain veneer and had a good effect. The postoperative smiling of patients is harmonious and beautiful, which is in line with the expected effect. Patient participation and satisfaction are high; thus, this method is worthy of clinical promotion.
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BACKGROUND: There is no mature computer-aided design and manufacturing system for the preparation of removable partial denture in China so far. There is no report involving large sample size. Most of the existing studies only investigated the wear effect of a few cases, and there is a need to accumulate and enrich clinical data. OBJECTIVE: To explore the application value of intraoral scanning and 3D printing in the manufacture of removable partial dentures for patients. METHODS: Sixty-three patients with Kennedy class I dentition defect who received treatment in the Shanghai Ninth People’s Hospital, Shanghai JiaoTong University School of Medicine, China were included in this study. These patients consisted of 29 males and 34 females and were aged 44-63 years. In the study group, 23 patients were treated with denture scaffolds by intraoral scanning and three-dimensional printing, while in the control group, 40 patients were treated with denture scaffolds by traditional impression. The wear effect was compared between two groups after repair. The masticatory efficiency was compared between two groups before and 6, 12 and 24 months after repair. At the last follow-up, patients' satisfaction and complications were compared between the study and control groups. This study was approved by Shanghai Ninth People’s Hospital, Shanghai JiaoTong University School of Medicine (approval No. TJBDYY-2014-13-R1) in March, 2014. RESULTS AND CONCLUSION: The fitness (96% vs. 70%), retention (83% vs. 58%) and stability index (83% vs. 53%) of the study group were significantly higher than those of the control group (all P 0.05). At 12 and 24 months after repair, the masticatory efficiency in the study group was significantly higher than that in the control group (P 0.05). These results suggest that intraoral scanning and 3D printing could obtain a more accurate stent model in the manufacture of partial dentures compared with traditional impression, thereby has a higher application value.
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Objective@# To explore the application of digital technology in the restoration of partial edentulous patients with microstomia. @*Methods@# A patient with microstomia was presented and seeking for the restoration of her full edentulous in the upper jaw and partial edentulous in the lower jaw (Kennedy Ⅲ). A digital intraoral scanning was used to obtain digital impressions of soft and hard tissues in the oral cavity. Computer aided design and 3D printing technology were used to design and fabricate the metal framework. @* Results @#The patient had no difficulty to wear or take off the dentures. The maxillary and mandibular dentures showed good retention, stability, mastication function and articulation. There was no tenderness in the one week and one month′s follow-up. And the chewing efficiency was satisfactory@*Conclusion@#This case report successfully designed and fabricated mandibular removable partial dentures for patients with microstomia through intraoral scanning and 3D printing technology. Thus, this work provides a new method and idea for treating partial edentulous dentition with microstomia
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Objetivo: O uso de scanners intraorais em Odontologia, visando à reprodutibilidade de dentes e arcadas dentárias, tem sido uma nova tendência na última década. As imagens obtidas são utilizadas principalmente em diagnóstico e planejamento de casos clínicos, mas podem também ser impressas, materializando-se em modelos e troqueis de acordo com a necessidade específica. Materiais e métodos: uma revisão de literatura foi conduzida, via PubMed e Google Acadêmico. Os artigos mais relevantes nas áreas relacionadas foram identificados. Dessa seleção, 30 artigos foram revisados e discutidos. Resultados: técnicas, equipamentos e marcas comerciais, com suas relativas vantagens e desvantagens, são apresentados à comunidade odontológica. Sob o ponto de vista técnico-científico, a acuidade e a precisão dos processos de escaneamento e impressão são as principais demandas e devem ser cuidadosamente testadas. Sob o ponto de vista clínico, a facilidade de cada operação, os requisitos necessários para que se realizem (por exemplo, uso de contraste), o tamanho e peso dos equipamentos (em especial da câmera intraoral), o processo de esterilização, o tempo de escaneamento e o conforto do paciente são os fatores mais relevantes. Do ponto de vista comercial, a disponibilidade dos equipamentos, seu preço e sua assistência técnica são as principais condições a serem consideradas pelos profissionais que pretendem aplicar o método de "moldagem virtual". Conclusão: os equipamentos avaliados apresentam claras vantagens e desvantagens, que precisam ser consideradas pelos compradores em potencial dessa tecnologia. Relevância clínica: este artigo visa informar profissionais da área de Odontologia sobre as principais características e limitações do escaneamento intraoral nas áreas de Ortodontia, Prótese, Implantodontia e Cirurgia Ortognática.(AU)
Introduction: the use of intraoral scanners for teeth and dental arches reproduction in dentistry has become a new trend in the last decade. The images acquired are used in diagnosis and treatment planning of clinical cases, but they can also be printed, materialized in dental casts and dies, depending on the specific needs. Materials and Methods: a review of the literature was conducted using PubMed and Google Scholars. Thirty articles were found to be the most relevant and selected to be included in this literature review. Results: techniques, equipment, and commercial brands, including their advantages and disadvantages, have been introduced to the dental community. From the technical-scientific point of view, the accuracy and precision of scanning and printing processes are the main demands, and must be carefully tested. From the clinical standpoint, easiness of operation, need of contrast agent (i.e, titanium dioxide powder), the size and weight of equipment wand, infection control, scanning time, and patient comfort are the most relevant factors. From the commercial point of view, equipment availability, price and available assistance are the main conditions to be considered by the professionals interested in the "virtual impression" method. Conclusion: apparatus es described in this literature review present clear advantages and disadvantages, which need to be taken into consideration by potential buyers of this technology. Clinical relevance: the article intents to inform dental professionals about the main features and limitations of the intraoral scanning in Orthodontics, Prosthodontics, Implantodontics and Oral Maxillofacial Surgery..(AU)
Subject(s)
Dentistry , Microscopy, Confocal , Tomography, Optical CoherenceABSTRACT
PURPOSE: The aim of this study is to evaluate the appropriate impression technique by analyzing the superimposition of 3D digital model for evaluating accuracy of conventional impression technique and digital impression. MATERIALS AND METHODS: Twenty-four patients who had no periodontitis or temporomandibular joint disease were selected for analysis. As a reference model, digital impressions with a digital impression system were performed. As a test models, for conventional impression dual-arch and full-arch, impression techniques utilizing addition type polyvinylsiloxane for fabrication of cast were applied. 3D laser scanner is used for scanning the cast. Each 3 pairs for 25 STL datasets were imported into the inspection software. The three-dimensional differences were illustrated in a color-coded map. For three-dimensional quantitative analysis, 4 specified contact locations(buccal and lingual cusps of second premolar and molar) were established. For twodimensional quantitative analysis, the sectioning from buccal cusp to lingual cusp of second premolar and molar were acquired depending on the tooth axis. RESULTS: In color-coded map, the biggest difference between intraoral scanning and dual-arch impression was seen (P.05).
Subject(s)
Humans , Axis, Cervical Vertebra , Bicuspid , Dataset , Molar , Periodontitis , Temporomandibular Joint Disorders , ToothABSTRACT
With the recent progress of digital technology, the computer guided surgery utilizing a guide template in the placement of implant has been actively performed, and the method employing the intraoral scanner at the implant prosthesis introduced. Fabrication method of the guide template can be largely classified into design-related rapid prototyping (RP) system and vector milling system, and each of the method has its own weakness in the clinical application despite of excellent accuracy. Thus, in this case study, a working model was fabricated by the wax RP technology using images acquired by CBCT and an intraoral scanner, and the metal bushing was picked up with orthodontic resin cast upon the wax model. Using this method, a surgical guide template was fabricated and used in surgery. From this, we could obtain a satisfactory outcome clinically in the implant placement and the fabrication of the final prostheses and thus report this case herein.
Subject(s)
Prostheses and ImplantsABSTRACT
OBJECTIVE: This study aimed to evaluate the accuracy and precision of polyurethane (PUT) dental arch models fabricated using a three-dimensional (3D) subtractive rapid prototyping (RP) method with an intraoral scanning technique by comparing linear measurements obtained from PUT models and conventional plaster models. METHODS: Ten plaster models were duplicated using a selected standard master model and conventional impression, and 10 PUT models were duplicated using the 3D subtractive RP technique with an oral scanner. Six linear measurements were evaluated in terms of x, y, and z-axes using a non-contact white light scanner. Accuracy was assessed using mean differences between two measurements, and precision was examined using four quantitative methods and the Bland-Altman graphical method. Repeatability was evaluated in terms of intra-examiner variability, and reproducibility was assessed in terms of inter-examiner and inter-method variability. RESULTS: The mean difference between plaster models and PUT models ranged from 0.07 mm to 0.33 mm. Relative measurement errors ranged from 2.2% to 7.6% and intraclass correlation coefficients ranged from 0.93 to 0.96, when comparing plaster models and PUT models. The Bland-Altman plot showed good agreement. CONCLUSIONS: The accuracy and precision of PUT dental models for evaluating the performance of oral scanner and subtractive RP technology was acceptable. Because of the recent improvements in block material and computerized numeric control milling machines, the subtractive RP method may be a good choice for dental arch models.