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1.
Int J Prosthodont ; 34(1): 27-36, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33570517

RESUMEN

PURPOSE: To investigate the effect of training on scanning accuracy of complete arch scans (CAS) performed by first-time users, with a distinction made between specific training (repeated performance of CAS) and nonspecific training (simple use of an intraoral optical scanner for a sextant scan in the context of a CAD/CAM teaching module). MATERIALS AND METHODS: A total of 36 students with no experience in intraoral scanning were randomized into three groups (n = 12 per group) according to the number of CAS sessions: three sessions (3S), two sessions (2S), and one session (1S). Each student had to perform 10 CAS per scanning session. Sessions were scheduled at T0, T1, and T2 for group 3S; at T0 and T2 for group 2S; and at T2 for group 1S. Before the final scanning session in each group (ie, the first scanning session in group 1S), the students completed a CAD/CAM teaching module, which included fabrication of a monolithic crown in a fully digital chairside workflow. RESULTS: In all groups, repeated CAS resulted in improved scanning accuracy. Participation in the CAD/CAM module had a positive effect on initial accuracy for CAS. Mean absolute deviations in cross-arch distance were 84 µm (T0), 68 µm (T1), and 63 µm (T2) for group 3S; 79 µm (T0) and 61 µm (T2) for group 2S; and 67 µm (T2) for group 1S. CONCLUSION: To perform CAS with the best possible accuracy, specific training is highly recommended. In addition, nonspecific training leads to an improvement in initial scanning accuracy.


Asunto(s)
Diseño Asistido por Computadora , Coronas , Técnica de Impresión Dental , Modelos Dentales , Humanos , Imagenología Tridimensional , Flujo de Trabajo
2.
Int J Prosthodont ; 34(1): 101-108, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33570525

RESUMEN

PURPOSE: To compare the accuracy of six intraoral scanners in two different partially edentulous maxillary models and to evaluate the effect of scanning sequence on accuracy. MATERIALS AND METHODS: Maxillary Kennedy Class I and Class IV situations were used as reference models. The reference datasets were obtained by scanning the models using a highly accurate industrial scanner (ATOS Core 80, GOM). The following six intraoral scanners were evaluated: Trios 3 (3Shape), iTero Element 2 (Align Technology), Emerald (Planmeca), CEREC Omnicam (Dentsply Sirona), CEREC Primescan (Dentsply Sirona), and Virtuo Vivo (Dental Wings). A total of 120 scans from both models were obtained using the six intraoral scanners and divided into two groups based on scanning sequence. Accuracy was evaluated by deviation analysis using 3D image processing software (Geomagic Studio 12, 3D Systems). Kruskal Wallis and Mann-Whitney U tests were performed (P ≤ .05) for statistical analysis. RESULTS: There were significant differences in the accuracy of digital impressions among intraoral scanners and scanning sequences. The trueness of the Trios scanner and the precision of the Trios, Primescan, and iTero scanners were significantly higher than for the other scanners. The Emerald had the lowest accuracy among the six intraoral scanners tested. Accuracy was affected by scanning sequence when using the Virtuo Vivo, Emerald, Primescan, and iTero. CONCLUSION: In Kennedy Class I and Class IV partially edentulous cases, it is useful to consider that the intraoral scanner used may affect the accuracy of the digital impression.


Asunto(s)
Técnica de Impresión Dental , Modelos Dentales , Diseño Asistido por Computadora , Arco Dental , Dentición , Imagenología Tridimensional
3.
Int J Prosthodont ; 34(1): 118-119, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33570527

RESUMEN

Intraoral scanners have been used to capture data for the design and subsequent manufacture of dental restorations and also for registering color clinical images. Scanners can capture datasets for future use and comparisons. This manuscript describes the potential of using software algorithms to superimpose 3D images captured at different times to calculate dimensional changes at the click of a button in various dental fields. 3D patient monitoring, with the advance of artificial intelligence and its built-in capacity for data analyses, will allow dentists and researchers to calculate volumetric changes and predict potentially adverse clinical outcomes.


Asunto(s)
Diseño Asistido por Computadora , Modelos Dentales , Inteligencia Artificial , Humanos , Imagenología Tridimensional , Monitoreo Fisiológico
4.
Niger J Clin Pract ; 24(1): 1-7, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33473018

RESUMEN

In the domain of orthodontics, plaster models are contemplated as one of the important tools for diagnosis and treatment planning. In Dentistry, technological advancement has developed in the section of diagnostic devices, for example, the utilization of a 3D intraoral scanner, which can convert plaster models into digital models. With in-office utilization of this system, orthodontists can more meticulously and precisely construct custom braces, clear aligners, and orthodontic appliances. The digital data can be stored as a stereolithography file; it eliminates the disadvantages encountered with the storage of plaster models like breakage, space required, and distortion of the plaster models. ITero®element is the intraoral laser scanner (ILS) which utilizes parallel confocal scanning technology which maximizes the accuracy of the scan. By utilizing the iTero scanner, the dental measurement can be performed in OrthoCADTM software which is highly accurate. The objective of the contemporary study is to review the literature of studies on in-vivo and ex-vivo scanning with the iTero system.


Asunto(s)
Imagenología Tridimensional , Ortodoncia , Diseño Asistido por Computadora , Técnica de Impresión Dental , Modelos Dentales , Humanos , Aparatos Ortodóncicos , Cintigrafía
5.
J Biol Regul Homeost Agents ; 35(1): 161-169, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33435664

RESUMEN

For dental impression of a prepared tooth, the goal is a void-free negative representation from which an accurate cast of a tooth and its surrounding tissue can be reproduced. This in-vitro study assessed and compared the reproduction accuracies of surface detail obtained with three different dental elastomeric impression materials: vinyl polysiloxane (VPS), vinyl polyether silicone (VPES), and polyether (PE). A stainless-steel model with two abutments was used, with impressions taken 10 times for each material, for 20 abutment impressions per group, using a two-phase, one-step technique (heavy body/light body). The impressions were removed and assessed for numbers of enclosed voids and open voids visible on the surface. The defect frequency was 95% for impressions with the VPS and VPES materials, and 30% for the PE material. No significant differences were seen for number of impressions with defects for VPS versus VPES. Significant differences were seen for VPS and VPES versus the PE material (P <.05). No significant differences were seen for the defect type distributions across these three impression materials. The PE impression material showed better accuracy for reproduction of surface detail of these dental impressions compared to the VPS and VPES impression materials.


Asunto(s)
Materiales de Impresión Dental , Técnica de Impresión Dental , Modelos Dentales , Ensayo de Materiales , Reproducibilidad de los Resultados , Propiedades de Superficie
6.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(6): 1112-1116, 2020 Dec 18.
Artículo en Chino | MEDLINE | ID: mdl-33331323

RESUMEN

OBJECTIVE: To assess the effect of disinfectant (Cavicide) with benzethon chloramine and isopropanol as main active ingredients disinfectant on dental impression accuracy. METHODS: The effect of Cavicide on three impression materials (alginate, polyether and vinylpolysiloxane) were assessed using a standard model. The standard model was digitized by an extraoral scanner (IScan D103i, Imetric). For each kind of impression materials, thirty impressions were taken following the manufactures' instruction in the same conditions. Subsequently, the impressions were randomly divided into three groups, with ten impressions in each group. After the impression taking was completed, the three groups underwent pure water rinse for 1 min (blank control, BC), 2% glutaraldehyde solution immersion disinfection for 30 min (glutaraldehyde, GD), and Cavicide solution spray disinfection for 5 min (Cavicide, CC), respectively. All the impressions were digitized by the extraoral scanner (IScan D103i, Imetric) after disinfection and exported to a dedicated three-dimensional analysis software (Geomagic Qualify 2014, Geomagic, USA). In the software, the digital models of the impressions were trimmed to teeth and then superimposed with the digitized standard model via best-fit alignment. Root mean square (RMS) was used to evaluate the deviations between the impression and the standard model. The deviation in the anterior and posterior regions was evaluated respectively. One-way ANOVA test and the LSD post-hoc test were used to compare the deviations between the three groups (P < 0.05). The color map of each superimposition was saved for visual analysis. RESULTS: For the polyether and vinylpolysiloxane materials, the difference between the three groups was not statistically significant (P=0.933, P=0.827). For the alginate material, the difference in posterior region between group GD and group BC, as well as group GD and group CC were statistically significant (GD vs. BC, P=0.001; GD vs. CC, P=0.002), while the difference between group BC and group CC was not statistically significant (P=0.854). The visual analysis showed an obvious deviation in the buccal-lingual direction in group GD. CONCLUSION: Disinfectant (Cavicide) with benzethon chloramine and isopropanol as main active ingredients using spray disinfection has no effect on the accuracy of the alginate, polyether and vinylpolysiloxane impressions.


Asunto(s)
Desinfectantes , 2-Propanol , Cloraminas , Materiales de Impresión Dental , Técnica de Impresión Dental , Modelos Dentales , Desinfección
7.
Am J Orthod Dentofacial Orthop ; 158(5): 759-766, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33131565

RESUMEN

INTRODUCTION: The use of digital models in orthodontics is becoming increasingly widespread. This study aimed to evaluate the accuracy and performance of digital intraoral scanning under 4 different intraoral environmental conditions. METHODS: Four digital models were acquired with TRIOS intraoral scanner (3Shape, Copenhagen, Denmark) for 50 subjects. A total of 200 digital models were divided into 4 groups as follows: daylight and saliva (group 1), daylight with saliva isolation (group 2), reflector light and saliva (group 3), and relatively dark oral environment and saliva (group 4). The 4 digital models were superimposed, and the edges of the models were trimmed to create common boundaries (Geomagic Control X; 3D Systems, Rock Hill, SC). Group 2 models were used as a reference and superimposed separately with the models of the other 3 groups. Deviations between corresponding models were compared as means of negative deviation, means of positive deviation, in total area, out total area, positively positioned areas, and negatively positioned areas. In addition, all groups were compared in terms of scanning time, the total number of images, and the mesiodistal width of teeth. RESULTS: Overlapping of group 1 with the reference model (group 2), a surface deviation of 13.1% (out total area) was observed. This analysis revealed that a 13% deviation was caused by the presence of saliva alone. This rate was 12.6% in group 3 and 15.5% in group 4, respectively. The values for means of negative deviation were -55 µ in group 1,-63 µ in group 3, and -68 µ in group 4. Means of positive deviation values were distributed among groups as follows: 68 µ in group 1, 69 µ in group 3, and 78 µ in group 4. The total number of images was observed, at least in group 4. CONCLUSIONS: The intraoral scanner performance was affected by different environmental conditions, and that caused variations on the surface of digital models. However, the performance of the intraoral scanner was independent of the scanning time and mesiodistal width of the teeth.


Asunto(s)
Técnica de Impresión Dental , Saliva , Diseño Asistido por Computadora , Modelos Dentales , Humanos , Imagenología Tridimensional
8.
Am J Orthod Dentofacial Orthop ; 158(5): e99-e109, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33131571

RESUMEN

INTRODUCTION: This research aimed to compare the estimation error of the root axis using 3-dimensional (3D) tooth models at the midtreatment stage between the whole-surface scan (WSS) and lingual-surface scan (LSS) methods. METHODS: The sample consisted of 208 teeth (26 each of central incisors, canines, second premolars, and first molars in the maxillary and mandibular dentition) from 13 patients whose pre- and midtreatment intraoral scan and cone-beam computed tomography (CBCT) were available. The 3D tooth models were constructed by merging the intraoral-scan crowns and the CBCT-scan roots obtained at the pretreatment stage. To estimate the root axis at the midtreatment stage, we superimposed the individual 3D tooth models onto the midtreatment intraoral scan obtained by the WSS and LSS methods. The midtreatment CBCT scan was used as the gold standard to determine the real root axis. The estimated root axis in terms of mesiodistal angulation and buccolingual inclination was measured in the WSS and LSS methods, and statistical analysis was performed. RESULTS: The estimation errors of the mesiodistal angulation and buccolingual inclination were <2.0° in both methods. The LSS method demonstrated a statistically larger but clinically insignificant estimation error than the WSS method in the mandibular canine (mesiodistal angulation, 1.95° vs 1.62°) and the total tested teeth (mesiodistal angulation, 1.40° vs 1.29°; buccolingual inclination, 1.51° vs 1.41°). CONCLUSIONS: Because the estimation errors of the root axis angle using the 3D tooth model by the WSS and LSS methods were within the clinically acceptable range, the root axis can be estimated by both methods.


Asunto(s)
Modelos Dentales , Raíz del Diente , Tomografía Computarizada de Haz Cónico , Humanos , Maxilar/diagnóstico por imagen , Corona del Diente/diagnóstico por imagen , Raíz del Diente/diagnóstico por imagen
9.
Am J Orthod Dentofacial Orthop ; 158(6): 807-815, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33012595

RESUMEN

INTRODUCTION: Maintenance of the intercanine and intermolar distances reduces the risk of relapse and increases the chance of stability; these values represent the limits of the arch, resulting from the muscular balance of each patient. The ideal would be to reproduce the patient's arch form individually. The Ricketts pentamorphic arch forms allow the clinician to choose among 5 shapes, the one that best fits the patient's arch form. The objective of this study was to evaluate the effect of orthodontic treatment without extraction according to the pentamorphic arch forms on mandibular arches of different forms. METHODS: Fifty patients were included in the study. For each patient, the pretreatment and end-of-treatment models were scanned by 3Shape Trios (3Shape, Copenhagen, Denmark) and transferred to the OrthoAnalyzer software (3Shape) version 2017-11.7.1.3 for measurements and superimpositions. The following measurements were made on the mandibular arches for both initial and final digital models: arch depth; intercanine distance, the distance between the first premolars, the distance between the second premolars, the distance between the first molars, and the distance between the second molars. Three superimpositions were made: superimposition between the initial arch and the corresponding form of the pentamorphic arch forms, superimposition between the final arch and the corresponding form of the pentamorphic arch forms, and superimposition between the initial arch and the final arch. The largest difference between the superimposed arches in each region was measured. RESULTS: This study showed that intercanine distance (P = 0.236), the distance between the first premolars (P = 0.074), and the distance between the first molars (P = 0.616) did not significantly change after orthodontic treatment. In contrast, the distance between the second molars (P = 0.028) and the arch depth (P <0.001) increased significantly after orthodontic treatment. The mean of the largest difference in the absolute value of all the superimpositions is significantly different from the theoretical value 0 (P <0.001), but clinically, this difference is significant only in certain premolars and molars regions. CONCLUSIONS: This study has shown that the pentamorphic arch forms maintained the arch shape in the sagittal and transverse directions, except for an expansion of the distance between the mandibular second molars.


Asunto(s)
Arco Dental , Modelos Dentales , Diente Premolar , Arco Dental/diagnóstico por imagen , Humanos , Mandíbula , Diente Molar , Programas Informáticos
10.
J Oral Sci ; 62(4): 439-443, 2020 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-32908080

RESUMEN

This study evaluated the effect of a modified tray design on the accuracy of implant impressions in comparison with the non-splinted and splinted impression techniques. Two titanium frameworks were produced to fit two parallel implants and two divergent implants with a 15o angle. According to the frameworks employed, two acrylic resin master models were fabricated. For each model, 10 impressions were taken with every technique. The maximum framework principal strain was calculated for every generated cast. For the parallel implant model, the strains of the non-splinted (118.4 µÎµ), splinted (89.0 µÎµ), and modified tray design impression (49.4 µÎµ) techniques were statistically similar (P = 0.16). For the divergent implant model, all the impression techniques showed a considerably higher strain than the parallel implant model. The splinted (287.0 µÎµ) and the modified (262.9 µÎµ) tray design impression techniques showed similar strains for the divergent implant model, which were significantly less than the strains for the non-splinted impression (518.0 µÎµ) technique (P < 0.05). Therefore, for two parallel implants, all the impression techniques exhibited similar accuracy. When angulation existed between the implants, the splinted and the modified tray design impression techniques were more accurate than the non-splinted impression technique.


Asunto(s)
Implantes Dentales , Técnica de Impresión Dental , Materiales de Impresión Dental , Modelos Dentales , Prótesis Dental de Soporte Implantado
11.
J Orofac Orthop ; 81(6): 427-439, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32897413

RESUMEN

PURPOSE: This study investigates the accuracy of abutment transfer with current impression materials and provides a concise overview, including other relevant factors, in order to enable clinicians to make an informed decision about the optimal impression for this treatment procedure. METHODS: In all, 96 impressions of a cadaver head with two orthodontic miniscrews in place were taken with four common impression materials by two observers and using two methods of application. After pouring with a standard type IV stone and abutment transfer, all models and the upper jaw (which had been separated from the head) were scanned in a standard model scanner (Zirkonzahn® [Zirkohnzahn GmbH, Gais, Italy] S600 ARTI) and evaluated using a computer-aided design (CAD) program (GOM-Inspect [Gesellschaft für optische Messtechnik m.b.H., Braunschweig, Germany]). The deviations were measured at six points per screw and statistically evaluated with SPSS® (IBM, Chicago, IL, USA). RESULTS: Optimal values were obtained with biphasic polyvinylsiloxane, while monophasic polyvinylsiloxane, alginate and polyether also resulted in acceptable accuracy. Observer experience showed no effect and the method of application had only a minor effect on accuracy. CONCLUSIONS: Within the limitations of this study, it seems that all impression materials are suitable for miniscrew abutment transfer, provided that methods of intraoral adaptation of the orthodontic appliance can be employed. If higher accuracy is needed or for clinicians with less experienced, a biphasic polyvinylsiloxane impression with the putty-wash technique should be used as this combination reduces setting time. The most cost-effective version, alginate, can be used if the consequences of greater deviations can be handled. Caution is advised with polyether if undercuts are present.


Asunto(s)
Técnica de Impresión Dental , Modelos Dentales , Materiales de Impresión Dental , Alemania , Italia
12.
Quintessence Int ; 51(9): 776-779, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32901238

RESUMEN

Virtual planning in digital dentistry enables easier communication between technicians, clinicians, and patients, and faster performance. Dental computer-aided design (CAD) software programs have been used for this purpose. One of the most crucial steps in virtual planning is mounting and articulating the maxillary and mandibular arch 3D models to simulate and evaluate the occlusion as a part of the virtual mock-up. The aim of this article was to describe a more cost-effective digital technique utilizing a scanned interocclusal record for articulating the cast models virtually. For this purpose, the open source Autodesk Meshmixer software program was used.


Asunto(s)
Modelos Dentales , Flujo de Trabajo , Diseño Asistido por Computadora , Humanos , Maxilar , Programas Informáticos
13.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(9): 647-653, 2020 Sep 09.
Artículo en Chino | MEDLINE | ID: mdl-32878400

RESUMEN

Objective: To prepare a three-dimensional (3D) printing donor tooth model and to observe its application in the peri-operative period. Methods: In part one, 192 cases (2017.9-2019.8) from Department of Oral & Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University ï¼»107 males and 85 females, age (34.2±10.7) yearsï¼½ which need autotransplantation of teeth (ATT) were collected. Whether the donor teeth can be completely extracted was predicted through clinical and imaging examination (first prediction). The second prediction was supplemented by the three-dimensional printing model of the donor teeth. Each of the prediction was compared with the actual results and the coincidence rate was calculated. In part two, 64 cases (2017.9-2019.8) from Department of Oral & Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University ï¼»28 males, 36 females, age (30.2±8.3) yearsï¼½ which need ATT were randomly divided into the model group and the donor group. The time of alveolar fossa preparation, time of donor tooth in vitro, times of trial implantation and time of pulptomy and root canal location were recorded respectively. Results: In part one, the coincidence rate between the second prediction and the actual results ï¼»97.4%(187/192)ï¼½ was significantly higher than that of the first prediction ï¼»93.2%(179/192)ï¼½ (P<0.05). In part two, the preparation time of the alveolar fossa in the maxillary and mandibular were (18.8±4.6) and (22.7±3.4) min, the time of the teeth in vitro were (3.0±0.6) and (2.1±0.6) min, the times of trial implantation were (1.3±0.8) and (1.0±0.9), and the time of pulpotomy and root canal location were (4.3±0.6) and (4.0±0.5) min. All values in the model groups were better than those in the donor group (P<0.05). Conclusions: The 3D printing model is accurate. It can be used in autogenous tooth transplantation to shorten the preparation time of alveolar fossa and time of donor tooth in vitro, and reduce the times of trial implantation of donor teeth, and to help to improve the prediction accuracy of complete extraction of donor teeth and the time of pulpotomy and root canal location.


Asunto(s)
Cirugía Asistida por Computador , Diente , Modelos Dentales , Femenino , Masculino , Impresión Tridimensional , Trasplante Autólogo
14.
Bull Tokyo Dent Coll ; 61(3): 169-178, 2020 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-32801261

RESUMEN

Victim identification following disasters is an important task for the dentist. Use of records of previous dental treatment proved effective in victim identification after the crash of Japan Airlines Flight 123 in 1985. This dental identification procedure can be problematic, however. In exceptional cases, the victim may have had very little or no prior treatment, making identification by this means impossible. The purpose of this study was to establish a new method of dental identification based on morphological comparison of the oral cavity, rather than on evidence of prior dental treatment. This new method involves superimposing 3-dimensional (3-D) models created by digital impression-taking devices, use of which is becoming increasingly widespread in present-day dental treatment. A total of 75 dental models were used to obtain 3-D models. These were then used in a total of 77 superimposition tests. The results demonstrated that the degree of similarity was 98.03-41.30%, and the degree of difference 0.17-29.69%. This indicated that differences among the dental models could be identified with 100% precision. Personal identification by superimposition of such 3-D models offers a useful tool that could compensate for the shortcomings of standard dental identification.


Asunto(s)
Técnica de Impresión Dental , Modelos Dentales , Diseño Asistido por Computadora , Imagenología Tridimensional , Japón
15.
PLoS One ; 15(7): e0236425, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32726330

RESUMEN

Craniofacial asymmetry, mandibular condylar modeling and temporomandibular joint disorders are common comorbidities of skeletally disproportionate malocclusions, but etiology of occurrence together is poorly understood. We compared asymmetry, condyle modeling stability and temporomandibular health in a cohort of 128 patients having orthodontics and orthognathic surgery to correct dentofacial deformity malocclusions. We also compared ACTN3 and ENPP1 genotypes for association to clinical conditions. Pre-surgical posterior-anterior cephalometric and panometric radiographic analyses; jaw pain and function questionnaire and clinical examination of TMD; and SNP-genotype analysis from saliva samples were compared to assess interrelationships. Almost half had asymmetries in need of surgical correction, which could be subdivided into four distinct morphological patterns. Asymmetric condyle modeling between sides was significantly greater in craniofacial asymmetry, but most commonly had an unanticipated pattern. Often, longer or larger condyles occurred on the shorter mandibular ramus side. Subjects with longer ramus but dimensionally smaller condyles were more likely to have self-reported TMD symptoms (p = 0.023) and significantly greater clinical diagnosis of TMD (p = 0 .000001), with masticatory myalgia most prominent. Genotyping found two significant genotype associations for ACTN3 rs1671064 (Q523R missense) p = 0.02; rs678397 (intronic SNP) p = 0.04 and one significant allele association rs1815739 (R577X nonsense) p = 0.00. Skeletal asymmetry, unusual condyle modeling and TMD are common and interrelated components of many dentofacial deformities. Imbalanced musculoskeletal functional adaptations and genetic or epigenetic influences contribute to the etiology, and require further investigation.


Asunto(s)
Actinina/genética , Deformidades Dentofaciales/genética , Predisposición Genética a la Enfermedad , Hidrolasas Diéster Fosfóricas/genética , Pirofosfatasas/genética , Trastornos de la Articulación Temporomandibular/genética , Adulto , Mentón/diagnóstico por imagen , Modelos Dentales , Deformidades Dentofaciales/diagnóstico por imagen , Deformidades Dentofaciales/patología , Deformidades Dentofaciales/cirugía , Cara/diagnóstico por imagen , Femenino , Estudios de Asociación Genética , Humanos , Maxilares/diagnóstico por imagen , Masculino , Maloclusión/diagnóstico por imagen , Maloclusión/genética , Maloclusión/patología , Maloclusión/cirugía , Cóndilo Mandibular/diagnóstico por imagen , Cóndilo Mandibular/patología , Cóndilo Mandibular/cirugía , Procedimientos Quirúrgicos Ortognáticos , Polimorfismo de Nucleótido Simple/genética , Trastornos de la Articulación Temporomandibular/diagnóstico por imagen , Trastornos de la Articulación Temporomandibular/patología , Trastornos de la Articulación Temporomandibular/cirugía
16.
Int J Prosthodont ; 33(4): 380-385, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32639697

RESUMEN

PURPOSE: To test the accuracies of different methods of digital vertical dimension augmentation (VDA) by comparison with a clinical situation. MATERIALS AND METHODS: Bite registrations with approximately 5 mm of VDA were made in the incisor regions of 10 subjects (mean VDA 4.5 mm). The conventional maxillary and mandibular stone casts in maximum intercuspation (MICP) and VDA bite registrations were digitized for all subjects using a laboratory scanner (control group). Lateral portraits were taken of all subjects to locate the position of the condylar axis. Four different digital VDA methods were compared to the control group: 100% rotation of the mandible referring to the lateral picture (100RL); 85% rotation and 15% translation referring to the lateral picture (85R15TL); 100% rotation in normal mounting mode of the Trios virtual articulator (100R); and jaw-motion analysis (JMA) equipment. The amount of VDA for each experimental group was compared to the control group. The augmented distances between the central incisors and the second molars were measured using 3D analyzing software. The ratio of the augmented distances between the posterior and anterior regions (P/A ratio) was calculated. One-way analysis of variance and multiple comparisons via least significant difference test were carried out to determine statistical significance. RESULTS: The P/A ratio of each group was as follows: Control = 0.61; 100RL = 0.55; 85R15TL = 0.61; 100R = 0.53; JMA = 0.52. Significant differences were observed for control vs JMA and for 85R15TL vs JMA (P < .05). The addition of translational movement was the primary factor for increasing the accuracy of digital VDA, with the lateral picture being a secondary factor. CONCLUSION: VDA using a virtual articulator with 100% rotation induces an error when compared to the clinical situation. When a clinician performs digital VDA, the setting of 85% rotation and 15% translation produces results closer to the real clinical condition.


Asunto(s)
Articuladores Dentales , Modelos Dentales , Registro de la Relación Maxilomandibular , Mandíbula , Proyectos Piloto , Dimensión Vertical
17.
Int J Prosthodont ; 33(4): 410-417, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32639701

RESUMEN

PURPOSE: To evaluate the dimensional accuracy of impressions made using a new fast-setting polyether material. MATERIALS AND METHODS: A metallic reference model with two crown preparations, one inlay preparation, and three stainless steel precision balls was digitized to create a digital reference model. Sixteen one-step impressions were made for each of the four study groups, differing in impression material (regular-setting polyether [RSP] vs fast-setting polyether [FSP]) and technique (monophase vs dualphase), for a total of 64 specimens. Plaster casts fabricated from these impressions were digitized using 3D scans. Global accuracy was studied by evaluating distance and angle deviations between the replica and the reference model. Local accuracy was described in terms of trueness and precision of the aligned individual abutment tooth surfaces. RESULTS: For all impression materials and techniques, the local accuracy at the abutment tooth level was excellent. For surfaces prepared for crowns, mean trueness was < 10 µm, and mean precision < 12 µm. Inlay surfaces were associated with higher inaccuracies (mean trueness < 21 µm and mean precision < 37 µm). The greatest global inaccuracies were generally measured for the cross-arch span, with mean distance changes between -55 µm and -94 µm. For all aspects of studied accuracy, impressions with FSP were at least comparable to those fabricated with RSP. CONCLUSION: Within the limitations of this study, all tested polyether materials would allow for clinically acceptable impression making. The new fast-setting material could be an alternative to regular-setting polyether materials, especially for single crowns and small fixed partial dentures.


Asunto(s)
Técnica de Impresión Dental , Modelos Dentales , Coronas , Materiales de Impresión Dental , Incrustaciones
18.
J Biol Regul Homeost Agents ; 34(3 Suppl. 1): 107-116, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32618168

RESUMEN

The aim of this study was to evaluate the shape and the average size of the maxillary and mandibular arch in an Italian adolescents' sample with correct occlusion, using the digital technology. The study sample was composed, after the use of an extra-oral scanner and after the application of inclusion and exclusion criteria, by the digitized dental casts of 79 Italian adolescents (39 females and 40 males), aged 14±1 years, with correct occlusion. On each model, both upper and lower, the reference points of the dental arches (FA), of the alveolar bone (WALA ridges) and of the incisal edge of the central incisors were identified. With these points, using a software, fourteen parameters were evaluated for each cast: basal and dental intermolar and inter-canine width, basal and dental molar and canine depth, basal and dental molar and canine ratio, overjet, overbite. Finally, the shape of the arches was assessed, dividing it into ovoid, triangular or square. Chi-square test and Student's T-test for each parameter were adopted with a p<0,05 significance level. The results showed that the ovoid form was the most frequent, followed by the triangular one for the upper arch and by the rectangular one for the lower arch. On the canine level, both upper and lower, both for dental and for basal references, the triangular shape showed the lowest width and ratio values and the highest depth values in comparison with the other two groups. The square one showed the opposite situation, and the ovoid one presented in the intermediate value. On the molar level the trend is quite similar to the canine one. The results obtained maybe suggest that on a significant percentage of the patients of the sample is expected to use a preformed ovoid arch wire, and the data found could be useful to study the adequacy of the arch wires currently on the market or to design new ones. .


Asunto(s)
Maloclusión de Angle Clase II , Diente , Adolescente , Arco Dental/diagnóstico por imagen , Modelos Dentales , Femenino , Humanos , Italia , Masculino , Mandíbula/diagnóstico por imagen , Maxilar/diagnóstico por imagen , Diente Molar
19.
J Prosthodont ; 29(8): 660-678, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32613641

RESUMEN

PURPOSE: To systematically review in vitro and clinical studies comparing quantitatively the 3D accuracy (global implant deviations) of digital vs conventional implant impressions for partially and completely edentulous patients. MATERIALS AND METHODS: Electronic and manual searches were conducted to identify in vitro and clinical studies, reporting on the 3D accuracy between digital and conventional implant impressions. Secondary outcomes were the effect of implant angulation, type of conventional impression technique, and type of intraoral scanner on the accuracy of implant impressions. RESULTS: The inclusion criteria were met by 9 in vitro studies and 1 clinical study reporting on completely edentulous impressions, while 6 in vitro and 2 clinical studies reported on partially edentulous impressions. Quantitative meta-analysis was performed for 5 completely edentulous and 6 partially edentulous studies. The studies exhibited high values for heterogeneity. A random effects model was conducted to estimate the effect size. Based on 5 in vitro studies on completely edentulous impressions, the mean 3D implant deviation between conventional and digital impressions was 8.20 µm (95% CI: -53.56, 37.15) and the digital impressions had nominally less deviation (p = 0.72). Based on 1 clinical and 5 in vitro studies on partially edentulous impressions, the mean 3D implant deviation between conventional and digital impressions was 52.31 µm (95% CI: 6.30, 98.33) and the conventional impressions had nominally less deviation (p = 0.03). Five in vitro and 2 clinical studies were not included in the quantitative analysis due to heterogeneity in the methodology. Implant angulation affected the accuracy in favor of the partially edentulous conventional impressions whereas the effect of different scanners was not statistically significant on the completely edentulous impressions (p = 0.82). CONCLUSIONS: Digital scans appear to have comparable 3D accuracy with conventional implant impressions based mainly on in vitro studies. However, clinical trials are recommended to investigate the clinical accuracy of digital scans and digitally fabricated interim or prototype prostheses, before digital implant scans can be recommended for routine clinical use.


Asunto(s)
Implantes Dentales , Boca Edéntula , Diseño Asistido por Computadora , Materiales de Impresión Dental , Técnica de Impresión Dental , Modelos Dentales , Humanos
20.
Acta Odontol Latinoam ; 33(1): 3-5, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32621592

RESUMEN

The aim of this study was to compare the accuracy and precision of 3D printers used to obtain models of fixed dental prostheses. A fixed dental prosthesis preparation was scanned and reproduced by four 3D printers: RapidShape P40, Asiga MAX, Varseo, and Photon. The impressions were scanned again, and the dataset was compared to the original dataset. Mean discrepancies (µm) were 52.97±20.48 (RapidShape P40), 68.27±43.53 (Asiga MAX), 62.22±56.21 (Varseo), and 80.03±28.67 (Photon). There was no difference (p=0.314) in accuracy; however, the precision differed (p=0.015) among the 3D printers. The printers had distinct precision but did not differ in accuracy.


Asunto(s)
Modelos Dentales , Prótesis Dental , Impresión Tridimensional/normas , Humanos
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