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1.
J Prosthodont Res ; 64(3): 319-325, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32423658

RESUMO

PURPOSE: The purpose of this study was to evaluate the effectiveness of both a resin primer containing methyl methacrylate (MMA) and a silanizing agent on bonding to indirect resin composite blocks, using two types of build-up hybrid resin composites. METHODS: SHOFU BLOCK HC (Shofu) specimens were blasted with alumina, after which one of two surface treatments was applied: CERA RESIN BOND (Shofu, the Silane group) or HC primer (Shofu, the MMA group). Resin composites made using either Solidex Hardura (SDH, Shofu) or Ceramage Duo (CMD, Shofu) were built up and micro-tensile bond strength (µTBS) values were measured after storage in water for either 24h or 6 months (n=24 per group). The fracture surfaces after µTBS measurements and the resin block/build-up resin interfaces were observed by scanning electron microscopy (SEM). RESULTS: The bond strength of the Silane/SDH group significantly decreased after 6 months (p<0.001), whereas in the MMA group there was no significant loss after 24h or 6 months (p=0.99). In the CMD group, the bond strength after 6 months was significantly lowered in both the Silane group (p<0.001) and the MMA group (p<0.001), but the latter still showed greater adhesion. SEM images demonstrated that the matrix resin was partially destroyed at the fracture surfaces of the MMA group and fracture surface unevenness was observed. CONCLUSIONS: A primer containing MMA produced stronger bonding to CAD/CAM resin even after long-term aging compared to a silane treatment.


Assuntos
Colagem Dentária , Cimentos de Resina , Resinas Compostas , Desenho Assistido por Computador , Teste de Materiais , Microscopia Eletrônica de Varredura , Silanos , Propriedades de Superfície , Resistência à Tração
2.
J Contemp Dent Pract ; 21(3): 249-252, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32434969

RESUMO

AIM: The purpose of this study was to survey all United States Air Force (USAF) general dentists regarding their experience with computer-aided design/computer-aided manufacturing (CAD/CAM) while in a dental school. Dental school graduation year and location was compared to the type and amount of CAD/CAM training and clinical experience during dental school to better understand the differences and influence of this technology. MATERIALS AND METHODS: A survey consisting of six questions was sent through e-mail to 546 general dentists in the AF Dental Corps in 2018 of which 306 replied (56% response rate). RESULTS: Dentists who graduated in 2005 or earlier and between 2006 and 2009 stated they did not receive CAD/CAM training in dental school, while more respondents in the group of graduation years 2014-2017 stated that they did receive training. About 11% of the respondents who graduated in 2014-2017 completed 6-10 restorations and 9% completed 11 or more restorations compared to the other year groups. More respondents who graduated from a dental school in the southwest and southeast regions of the United States reported completing more restorations compared to other school regions. CONCLUSION: Computer-aided design/computer-aided manufacturing is now becoming a prevalent curriculum in US dental schools, both as a core requirement and an elective. Its training platforms varied from lectures and literature reviews to preclinical laboratory. CLINICAL SIGNIFICANCE: More respondents in the groups of graduation years 2014-2017 had completed more CAD/CAM restorations compared to other year groups; however, most of the respondents did not feel their training was sufficient enough to use CAD/CAM technology independently.


Assuntos
Desenho Assistido por Computador , Planejamento de Prótese Dentária , Odontologia Militar , Odontólogos , Humanos , Faculdades de Odontologia , Inquéritos e Questionários , Estados Unidos
3.
J Adhes Dent ; 22(3): 275-283, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32435768

RESUMO

PURPOSE: To evaluate the effect of surface conditioning methods and aging on the repair bond strength between resin composite and nanoceramic CAD/CAM resin. MATERIALS AND METHODS: Twenty-four blocks of nanoceramic CAD/CAM resin (NCR) (Lava Ultimate, 3M Oral Care) (10 x 5 x 2 mm3) and resin composite (Filtek Z350, 3M Oral Care) (RC) were made, embedded in acrylic resin, polished (#600, #800, #1200) and randomly divided into 8 groups (n = 12 each) according to surface conditioning methods (air abrasion with 30-µm CoJet [CJ] or air abrasion with 50-µm Al2O3 [AB]) and aging prior to repair (without aging, 24 h in water at 37°C; with aging 6 months in water at 37°C). The blocks were air abraded (20 s, 2.5 bar, 10 mm) using a standardized device. A layer of adhesive resin (Scotchbond Universal) was applied (20 s) and photopolymerized for 20 s. RC cylinders (Ø = 2 mm; h = 2 mm) were then bonded to the NCR substrates using a Teflon matrix and photopolymerized for 40 s. All specimens were thermocycled (10,000 cycles, 5°C-55°C) and submitted to the shear bond test (50 kgf, 0.5 mm/min) to measure repair strength. Data (MPa) were analyzed using 3-way ANOVA and Tukey's test (α = 0.05). Failure analysis was performed using stereomicroscopy (20X). RESULTS: ANOVA revealed a significant effect of only the "material" factor (p = 0.00). The group NCR6mCJ presented bond strengths (29.37 ± 5.41) which were significantly higher than those of the NCR24hCJ (20.88 ± 5.74) and RC groups (p < 0.05). The group RC24hCJ (19.71 ± 4.21) presented the lowest shear bond strength (p < 0.05). Failure analysis revealed predominantly type B mixed failures (adhesive+cohesive in the substrate material) except for the groups NCR24hCJ and NCR6mAB, where mainly type C failure (adhesive+cohesive at the RC) was observed. CONCLUSION: Air abrasion with Al2O3 particles or silicatization with CoJet followed by adhesive resin application are effective surface conditioning methods for the repair of nanoceramic CAD/CAM resin with resin composite.


Assuntos
Abrasão Dental por Ar , Resinas Compostas , Resinas Acrílicas , Desenho Assistido por Computador , Propriedades de Superfície
4.
Int J Prosthodont ; 33(3): 272-276, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32320179

RESUMO

PURPOSE: To analyze the clinical behavior of screw-retained monolithic lithium disilicate (LDS) implant-supported single crowns (ISSCs) over a 1-year follow-up. MATERIALS AND METHODS: A total of 28 patients were restored with 45 screw-retained monolithic LDS (press-fabricated) ISSCs bonded to titanium bases in posterior sites. Modified United States Public Health Service criteria and Kaplan-Meier survival and success rates were evaluated. RESULTS: A total of 27 patients with 44 ISSCs were evaluated 12 months (mean ± standard deviation: 13.02 ± 2.28) after prosthesis delivery. No implant or crown failures occurred. The Kaplan-Meier survival and success rates were each 100% after 1 year. Minorly increased surface roughness was noted in the occlusal contact point areas of 9 ISSCs (20.5% Bravo rating). Marginal adaptation, color match, and anatomical form stayed favorable over time. CONCLUSION: Press-fabricated LDS monolithic screw-retained implant crowns appear to be a promising treatment option for posterior implants under short-term observation.


Assuntos
Desenho Assistido por Computador , Coroas , Parafusos Ósseos , Porcelana Dentária , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante , Falha de Restauração Dentária , Humanos , Dados Preliminares , Estudos Prospectivos
5.
Int J Prosthodont ; 33(3): 333-340, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32320188

RESUMO

This report presents a digital technique for the fabrication of a two-piece hollow bulb maxillary obturator prosthesis. The procedure described resulted in an accurate prosthesis while avoiding the discomfort associated with analog impressions. The manipulation of a routine postoperative CT scan in conjunction with a 3D printer allowed for the fabrication of a 3D-printed anatomical cast, from which the two-piece hollow bulb obturator was fabricated. The obturator prosthesis framework was digitally designed and milled from a modified PEEK material, resulting in a lightweight prosthesis with excellent biocompatibility. The clinical and laboratory steps involved are described.


Assuntos
Desenho Assistido por Computador , Prótese Maxilofacial , Planejamento de Prótese Dentária , Cetonas , Polietilenoglicóis , Impressão Tridimensional
6.
Int J Prosthodont ; 33(3): 341-346, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32320189

RESUMO

Children affected by dentinogenesis imperfecta (DI) require restorative techniques or prosthodontic management to minimize the functional and psychosocial impacts of the condition. In cases of excessive wear of the deciduous dentition and moderate cooperation from the child, removable complete overdenture prostheses are the most suitable treatment option. However, limited restorative space is a technical challenge for the placement of such prostheses. Advances in digital technologies can help assist in the fabrication of monolithic prostheses with reduced thickness. The present clinical report describes the management of a moderately cooperative 7-year-old patient suffering from DI with severe tooth wear, reduced restorative space, and a high smile line. The design and fabrication of complete overdentures were performed using a digital workflow. This innovative monochromatic monolithic approach combined with the use of gingiva-shade composite resin respected the available restorative space while obtaining a natural esthetic appearance. Such a strategy requires regular denture replacement according to the child's growth and loss of deciduous dentition. An additional aim is to obtain the cooperation needed for a future global fixed rehabilitation over time.


Assuntos
Dentinogênese Imperfeita , Revestimento de Dentadura , Criança , Resinas Compostas , Desenho Assistido por Computador , Humanos , Odontopediatria
7.
Int J Oral Maxillofac Surg ; 49(5): 673-677, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32265088

RESUMO

In the case of pandemic crisis situations, a crucial lack of protective material such as protective face masks for healthcare professionals can occur. A proof of concept (PoC) and prototype are presented, demonstrating a reusable custom-made three-dimensionally (3D) printed face mask based on materials and techniques (3D imaging and 3D printing) with global availability. The individualized 3D protective face mask consists of two 3D-printed reusable polyamide composite components (a face mask and a filter membrane support) and two disposable components (a head fixation band and a filter membrane). Computer-aided design (CAD) was used to produce the reusable components of the 3D face mask based on individual facial scans, which were acquired using a new-generation smartphone with two cameras and a face scanning application. 3D modelling can easily be done by CAD designers worldwide with free download software. The disposable non-woven melt-blown filter membrane is globally available from industrial manufacturers producing FFP2/3 protective masks for painting, construction, agriculture, and the textile industry. Easily available Velcro fasteners were used as a disposable head fixation band. A cleaning and disinfection protocol is proposed. Leakage and virological testing of the reusable components of the 3D face mask, following one or several disinfection cycles, has not yet been performed and is essential prior to its use in real-life situations. This PoC should allow the reader to consider making and/or virologically testing the described custom-made 3D-printed face masks worldwide. The surface tessellation language (STL) format of the original virtual templates of the two reusable components described in this paper can be downloaded free of charge using the hyperlink (Supplementary Material online).


Assuntos
Máscaras , Pandemias , Desenho Assistido por Computador , Impressão Tridimensional
8.
Artigo em Inglês | MEDLINE | ID: mdl-32233198

RESUMO

A technology called Trace Registration (TR) has been introduced to allow dynamic navigation of implant placement without the need for a thermoplastic stent. This study was undertaken in order to validate the accuracy of the TR protocol for dynamically guided implant surgery. A retrospective, observational, in vivo study was performed using dynamic navigation via the TR protocol. The preoperative cone beam computed tomography (CBCT) plan was superimposed and registered (aligned) with the postoperative CBCT scan to assess accuracy parameters. A total of 136 implants were placed in 59 partially edentulous arches. Mean deviation between the planned and actual position for all implants was 0.67 mm at the coronal level (entry point), 0.9 mm at the apical level, and 0.55 mm in depth, with an angle discrepancy of 2.50 degrees. Tracing 5 to 6 teeth tended to improve accuracy results compared to tracing 3 to 4 teeth. TR is as accurate as traditional registration and statically guided methods for implant surgery.


Assuntos
Implantes Dentários , Boca Edêntula , Cirurgia Assistida por Computador , Desenho Assistido por Computador , Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endo-Óssea , Humanos , Imageamento Tridimensional , Estudos Retrospectivos
9.
Braz Oral Res ; 34: e035, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32321053

RESUMO

Although fiber-reinforced composites are commonly used in dental practice, whether fiber-reinforced crowns and fixed partial dentures can be used as definitive prostheses remains to be determined. This study used scanning electron microscopy to evaluate the load-bearing capacity of non-reinforced and fiber-reinforced composite (FRC) molar crowns prepared by computer-aided design/computer-aided manufacturing (CAD/CAM). The crowns were fabricated from three empirical FRC blocks, one empirical composite block, and one commercial ceramic block. The FRC resin was prepared by mixing BaO silicate particles, E-glass fiber, and dimethacrylate resin. Specimens were divided into five groups (n = 10), differing in the amounts of filler, resin, and fiber. Crowns were statically loaded until fracture. One-way analysis of variance and Tukey's post hoc multiple comparison tests were used for statistical analyses. The groups showed significant differences in load-bearing capacity; empirical bidirectional FRC resin blocks had the highest capacity, while commercial ceramic blocks had the lowest capacity. Molar crowns formed from FRC resin blocks had higher load-bearing capacity compared to non-reinforced composite resin and ceramic blocks. These results show that fiber reinforcement increased the load-bearing capacity of molar crowns.


Assuntos
Resinas Compostas/química , Desenho Assistido por Computador , Coroas , Suporte de Carga , Análise de Variância , Cerâmica/química , Planejamento de Prótese Dentária , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Dente Molar , Valores de Referência , Reprodutibilidade dos Testes , Propriedades de Superfície
10.
Ned Tijdschr Tandheelkd ; 127(3): 171-176, 2020 Mar.
Artigo em Holandês | MEDLINE | ID: mdl-32343277

RESUMO

3D virtual planning optimises the predictability of orthognathic surgery. The planning is based on a cone beam computed tomography-scan of the patient as well as a plaster model, and is transferred to the patient by a 3D printed occlusal splint. In 3D printing the build angle influences, among other things, the accuracy (in earlier research, proven in dental crowns), manufacturing time and capacity. In this research, using 10 plaster models, 3 different build angles (0°, 30° and 90°) are compared. The fit of the splints was tested by 2 physicians using plaster models. According to this small sample, the fit does not depend on the build angle. When considering the manufacturing time and capacity, there is a preference for the 90º oriëntation, because it increases the manufacturing capacity and decreases the manufacturing time per splint.


Assuntos
Placas Oclusais , Procedimentos Cirúrgicos Ortognáticos , Desenho Assistido por Computador , Coroas , Humanos , Imageamento Tridimensional , Impressão Tridimensional
11.
Am J Dent ; 33(2): 59-63, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32259408

RESUMO

PURPOSE: To evaluate Streptococcus mutans biofilm formation over different restorative dental materials. METHODS: Using a bioreactor over 72 hours, four commercially available ceramics were evaluated: IPS E-max Press, IPS E-max CAD, Lava Ultimate CAD-CAM, Vita Enamic and two resin composites (SR Nexco Paste and Brilliant NG). The results were evaluated using atomic force microscopy and confocal microscopy, the biofilm was stained and the arbitrary fluorescence units (AFU) quantified. RESULTS: The results showed that IPS E-max CAD had the lowest roughness values (4.29±1.79 nm), while the highest values were observed for Vita Enamic discs ( (77.13±17.35 nm). Analysis of S. mutans biofilm formation by AFU revealed lower values for IPS E-max CAD (6.77±1.67 nm); the highest values were found for Lava Ultimate (79.99±22.23 nm). Regarding the composite groups, SR Nexco Paste showed roughness values of 15.07±2.77 nm and lower arbitrary fluorescence units of 30.92±12.01 nm than Brilliant NT. There was a correlation between the surface roughness of ceramics and composite with S. mutans biofilm formation. CLINICAL SIGNIFICANCE: The adhesion of oral bacteria to restorative dental materials plays a key role in the success of dental treatment; the surface roughness influences the S. mutans biofilm formation.


Assuntos
Materiais Dentários , Streptococcus mutans , Biofilmes , Cerâmica , Desenho Assistido por Computador , Porcelana Dentária , Teste de Materiais , Propriedades de Superfície
12.
Stomatologiia (Mosk) ; 99(1): 43-48, 2020.
Artigo em Russo | MEDLINE | ID: mdl-32125301

RESUMO

AIM: The identification of personality based on dental status of the remains of presumably Evgenii Sergeevich Botkin physician-in-ordinary of the family of the Nicholas II. We examined the scull #2 (presumably attributed to Tsar's family physician-in-ordinary E.S. Botkin) fragments of edentulous maxilla and mandible in particular, 2 stereolithographic resin models of full dentures belonged to Botkin E.S. We utilized the following examination methods: Visual evaluation (odontoscopy, morphoscopy) Anthropometric analysis (odontometric and morphometric) 3D digital scanning of the studied objects Manual and digital superimposition of their contours Digital scanning was performed with the use of optical scanner device Neway Scanway 2017 12 REV C and also with NobelProcera 2G scanner. Outline superimposition was performed with Nobel Procera Software v3.1, Exocad 2.2, Romexis ver. 4.5.1. CBCT of the objects was acquired on Planmeca Promax 3D Mid. Results of the current investigation prove the congruency and conformity of the dentures to the bony remains of the jaws and with high probability confirm the assumption of the appurtenance of the examined copy of the denture to the dentoalveolar system of the described scull #2 and the object itself - identified as the scull of the physician-in-ordinary to the last Russian Royal family Evgenii Sergeevich Botkin.


Assuntos
Prótese Total , Prótese Parcial , Desenho Assistido por Computador , Mandíbula , Maxila , Federação Russa
13.
J Dent Educ ; 84(3): 358-366, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32176344

RESUMO

The aim of this study was to evaluate teeth prepared for computer-aided design/computer-aided manufacturing (CAD/CAM) restorations by senior dental students using recently developed rubrics. The rubrics used evaluation criteria based on four factors: retention or resistance form; marginal or internal adaption or manufacturing process; biology, esthetics, or durability of restorative material; and intraoral scanner impression. In academic year 2018-19, four faculty members used the rubrics to assess 111 first maxillary right premolars (tooth no. 4) prepared for lithium disilicate crowns and 223 second maxillary right premolars (tooth no. 5) and first maxillary right molars (tooth no. 3) prepared for monolithic zirconia partial fixed dental prostheses. The preparations had been performed on typodont teeth. The most common errors identified for tooth preparations were in the finish line quality (136 errors in 223 prostheses), a criterion that is crucial for quality CAD/CAM restorations. To prevent poorly fit CAD/CAM restoration preparations that result from an unacceptable finish line quality, students need to understand the rationale used to develop detailed rubrics and adhere to the defined critera.


Assuntos
Adaptação Marginal Dentária , Planejamento de Prótese Dentária , Desenho Assistido por Computador , Coroas , Porcelana Dentária , Humanos , Estudantes de Odontologia
14.
J Dent Educ ; 84(3): 329-335, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32176349

RESUMO

The aims of this study were to determine the convergence angles of posterior teeth prepared by dental students at the University of Toronto for lithium disilicate glass-ceramic (LDGC) CAD/CAM crowns and to investigate their effect on loss of retention rate. A total of 280 preparations for posterior monolithic LDGC CAD/CAM crowns were performed on 270 patients (169 women and 101 men). Crowns were cemented with RelyX Unicem and Calibra Universal resin cements. Mesial, distal, and angle of convergence were measured on the bitewing radiographs. Cemented crowns were followed for up to six years. Data were analyzed for tooth type and location and for operator experience. The results showed the majority of convergence angles were greater than the recommended guidelines but fell within a clinically acceptable range (20 to 24 degrees). However, angles of convergence for mandibular molar preparations were highest (28.06±5.50 degrees), while maxillary premolars exhibited the lowest values (24.72±6.59 degrees). No significant difference was found between the results of dental students and foreign-trained dentists. Over a six-year observation period, only two crowns lost retention. The findings of this study indicated that ideal taper angles were impractical and difficult to achieve in clinical education settings.


Assuntos
Coroas , Estudantes de Odontologia , Cerâmica , Desenho Assistido por Computador , Porcelana Dentária , Planejamento de Prótese Dentária , Feminino , Humanos , Masculino , Teste de Materiais
15.
Quintessence Int ; 51(4): 268-273, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32128525

RESUMO

OBJECTIVE: The objective of the present study was to assess the effect of monolithic and bilayer restorations considering heat-pressed and milled/CAD/CAM reinforced lithium disilicate ceramic veneers, on the flexural strength after cementation. METHOD AND MATERIALS: Thirty-five specimens were divided into five groups (n = 7), according to the restorative solution: 2-mm thickness composite resin (CR2); heat-pressed monolithic ceramic 0.6 mm (HPM), CAD/CAM monolithic ceramics 0.6 mm (CCM); heat-pressed monolithic ceramic 0.4 mm + 0.2 mm glass-ceramic (HPB); CAD/CAM monolithic ceramic 0.4 mm + 0.2 glass-ceramic (CCB). Specimens were cemented on composite resin bars and submitted to a three-point bending test on a Universal Testing Machine, until fracture. Fractured samples were analyzed under stereomicroscope and SEM. Flexural strength data were analyzed by one-way ANOVA and Tukey test. RESULTS: The control group showed the highest flexural strength results (119.57 ± 19.49 MPa), with values similar to groups HPM (98 ± 25.62 MPa) and CCM (96.14 ± 20.60 MPa). Groups HPB and CCB showed lower values when compared with the other groups. Fracture started from the base on monolithic groups and from ceramic on bilayer groups. CONCLUSION: Both ceramic systems (CAD/CAM and heat-pressed) have similar fracture strength, although bilayer restorations present lower strength when compared with monolithic ceramics.


Assuntos
Porcelana Dentária , Resistência à Flexão , Cerâmica , Resinas Compostas , Desenho Assistido por Computador , Análise do Estresse Dentário , Teste de Materiais , Propriedades de Superfície
16.
Quintessence Int ; 51(4): 304-308, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32128526

RESUMO

This paper describes an alternative computer-aided design/computer-aided manufacturing (CAD/CAM) technique for the creation of a combined prosthetic restoration with orthodontic appliance (PROA). This concept allows the use of orthodontic appliances such as brackets, attachments, or any other type of appliance over different types of prosthetic restorations. The PROA concept aims to mitigate problems associated with performing restorative treatment when orthodontic treatment is necessary. This proposed concept provides the clinicians with proper control and planning of the interdisciplinary treatment that will lead to the final tooth shape, form, and proportions while performing orthodontic tooth movements.


Assuntos
Desenho de Aparelho Ortodôntico , Aparelhos Ortodônticos , Desenho Assistido por Computador , Técnicas de Movimentação Dentária
17.
Swiss Dent J ; 130(3): 229-235, 2020 Mar 09.
Artigo em Alemão | MEDLINE | ID: mdl-32162856

RESUMO

This case report presents the treatment of a partially edentulous patient with a clasp-retained removable dental prosthesis (RDP) using both, digital and conventional workflows. Differences were demonstrated in impression taking, bite registration, manufacturing of models, prosthetic set-up, framework design and production; the technical steps for the finish of the RDPs were identical and (currently) still dependent on manual skills. The digitally 3D-printed framework were favored by the patient and the dentist due to the precise fit. The number of manual steps will be continuously reduced applying digital technologies for the treatment with RDPs, resulting in shortened clinical and technical work time and higher precision of the final prosthetic restoration. In addition, the use of intraoral scanners is more patient-friendly than classic impressions with elastomers. Technological advancements are required to eliminate today's limitations and enable a complete digital workflow, even without any physical models. Removable Dental Prosthesis 2.0: yes ­ but not yet completely from A to Z.


Assuntos
Prótese Parcial Removível , Boca Edêntula , Desenho Assistido por Computador , Técnica de Moldagem Odontológica , Planejamento de Prótese Dentária , Humanos , Fluxo de Trabalho
18.
Biomed Khim ; 66(1): 30-41, 2020 Jan.
Artigo em Russo | MEDLINE | ID: mdl-32116224

RESUMO

New drug discovery is based on the analysis of public information about the mechanisms of the disease, molecular targets, and ligands, which interaction with the target could lead to the normalization of the pathological process. The available data on diseases, drugs, pharmacological effects, molecular targets, and drug-like substances, taking into account the combinatorics of the associative relations between them, correspond to the Big Data. To analyze such data, the application of computer-aided drug design methods is necessary. An overview of the studies in this area performed by the Laboratory for Structure-Function Based Drug Design of IBMC is presented. We have developed the approaches to identifying promising pharmacological targets, predicting several thousand types of biological activity based on the structural formula of the compound, analyzing protein-ligand interactions based on assessing local similarity of amino acid sequences, identifying likely molecular mechanisms of side effects of drugs, calculating the integral toxicity of drugs taking into account their metabolism, have been developed in the human body, predicting sustainable and sensitive options strains and evaluating the effectiveness of combinations of antiretroviral drugs in patients, taking into account the molecular genetic characteristics of the clinical isolates of HIV-1. Our computer programs are implemented as the web-services freely available on the Internet, which are used by thousands of researchers from many countries of the world to select the most promising substances for the synthesis and determine the priority areas for experimental testing of their biological activity.


Assuntos
Desenho Assistido por Computador , Desenho de Fármacos , Preparações Farmacêuticas/química , Descoberta de Drogas , Humanos , Ligantes , Software
19.
Int J Comput Dent ; 23(1): 49-56, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32207461

RESUMO

AIM: Evaluation of appropriate models for computer-aided design/computer-aided manufacturing (CAD/CAM) in vitro studies by investigation of different model materials regarding suitability for intraoral scanners and dimensional stability. MATERIALS AND METHODS: A typodont model was prepared to accommodate a 10-unit prosthesis. The model was duplicated using six different materials: class IV die stone (DS), cobalt-chrome molybdenum (CoCrMo), epoxy resin (EPOX), polyurethane (PU), titanium (TI), and zirconia (ZI). An intraoral scanner was used to obtain three scans of each model. Reference datasets were generated using micro-computed tomography (micro-CT). The first scan was compared with the corresponding reference micro-CT dataset to assess its trueness. The precision was measured by comparing all scans within one test group. For the evaluation of dimensional stability, micro-CT was used to generate three-dimensional (3D) datasets of the models at different time intervals over a 6-week period. The models were kept under constant conditions during the study. All datasets were analyzed with software that determined the deviation of two datasets by alignment using a best-fit algorithm. RESULTS: The criterion of trueness was fulfilled by CoCrMo, EPOX, PU, and the typodont model. Scans of CoCrMo and ZI showed the best precision. PU and the typodont model did not meet the requirement of dimensional stability, whereas EPOX and gypsum were stable only for a period of 10 days. CONCLUSION: The CoCrMo model was the only one that met all the criteria for an appropriate model for CAD/CAM in vitro studies. The other investigated materials either lacked dimensional stability or could not be scanned accurately and reproducibly.


Assuntos
Desenho Assistido por Computador , Adaptação Marginal Dentária , Ligas de Cromo , Técnica de Moldagem Odontológica , Modelos Dentários , Humanos , Imageamento Tridimensional , Titânio , Microtomografia por Raio-X
20.
Int J Comput Dent ; 23(1): 73-82, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32207463

RESUMO

BACKGROUND: Accurate implant placement in the bone is key to successful implant treatment. Once inserted, it can be difficult to correct the orientation of the implant axis, especially of a one-piece implant. Prosthetic-driven digital implant planning in combination with fully guided implant surgery can offer additional safety in such cases. CASE PRESENTATION: The patient presented with a wide, edentulous interdental space extending from sites 13 to 16, which was to be restored with three one-piece zirconia implants supporting a zirconia fixed partial denture comprizing a cantilever to the mesial aspect. Digital planning based on DICOM (Digital Imaging and Communications in Medicine) and intraoral surface data was performed to ensure optimal positioning. Guided implant placement was executed using a contra-angle handpiece with special attachments and a compatible, sleeveless drill guide. Impressions of the implants for the final restoration were acquired using an intraoral scanner. Reflection-related errors were compensated for by using the given digital abutment geometry. The DICOM and STL datasets were superimposed and used as the basis for fabricating a monolithic zirconia restoration through a subtractive milling process. The final restoration was adhesively cemented. CONCLUSIONS: By using a prosthetic-driven implant planning strategy, it was possible to place the one-piece ceramic implants without an available implant manufacturer's guide-based solution. This was accomplished using a contra-angle surgical handpiece with special attachments and a compatible drill guide. This approach is particularly recommended for the placement of one-piece implants, which otherwise require irreversible abutment grinding for the adjustment of the implant axis orientation after placement. To increase the precision of the digital impressions of the implants, the ideal abutment geometry was imported and superimposed onto the scan data. The results demonstrate that the proposed method can dispense with the need for gingival retraction when acquiring impressions for implants of this type in the future.


Assuntos
Implantes Dentários , Fluxo de Trabalho , Cerâmica , Desenho Assistido por Computador , Prótese Parcial Fixa , Humanos
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