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1.
Head Face Med ; 16(1): 31, 2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-33243266

RESUMO

BACKGROUND: A new distraction osteogenesis assembly system comprising a fully customized CAD/CAM-based fixation unit and ready-made distraction unit was developed. The aim of this study was to introduce our new distraction system and to evaluate its accuracy level in a sampled mandibular distraction osteogenesis. METHODS: Our system consists of a fully customized CAD/CAM-based fixation plate unit with two plates for each moving and anchoring part, and a ready-made distraction unit with attachment slots for fixation plates. The experimental distractions were performed on 3D-printed mandibles for one control and two experimental groups (N = 10 for each group). All groups had reference bars on the chin region and teeth to measure distraction accuracy. The control group had the classical ready-made distraction system, and experimental groups 1 and 2 were fitted with our new distraction assembly using a different distractor-positioning guide design. All distracted experimental mandibles were scanned by CT imaging, then superimposed on a 3D simulation to get their discrepancy levels. RESULTS: The measured 3D distances between the reference landmarks of the surgical simulations and the experimental surgeries for the three groups were significantly different (p < 0.0001) by statistical analysis. The errors were greater in the control group (with a total average of 19.18 ± 3.73 mm in 3D distance between the simulated and actual reference points) than those in the two experimental groups (with an average of 3.68 ± 1.41 mm for group 1 and 3.07 ± 1.39 mm for group 2). The customized distraction assembly with 3D-printed bone plate units in group 1 and 2, however, did not show any significant differences between simulated and actual distances (p > 0.999). CONCLUSION: Our newly-developed distraction assembly system with CAD/CAM plate for the distraction osteogenesis of the mandible produced a greater level of accuracy than that of a conventional distraction device. The system appears to address existing shortcomings of conventional distraction devices, including inaccuracy in vector-controlled movement of the system. However, it also needs to be further developed to address the requirements and anatomical characteristics of specific regions.


Assuntos
Osteogênese por Distração , Placas Ósseas , Desenho Assistido por Computador , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Osteogênese
2.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(11): 864-870, 2020 Nov 09.
Artigo em Chinês | MEDLINE | ID: mdl-33171560

RESUMO

Objective: To evaluate long-term clinical outcome of implant-supported fixed prosthesis with the guidance of computer-aided design/computer-aided manufacturing (CAD/CAM) surgical template in old patients. Methods: Fifteen 50-67(58.6±5.3) year-old patients (11 males and 4 females) who received the digital implant surgery with the guidance of CAD/CAM surgical template and implant-supported fixed prosthesis in Department of Oral Implantology, Yantai Stomatological Hospital Affiliated to Binzhou Medical College from August, 2013 to Janurary, 2016 were included. There are 15 edentulous maxillas, 8 edentulous mandibles on which 145 implants were placed in total. After the placement of implant, the accuracy of CAD/CAM surgical template was assessed by comparing the post-operative 3-dimensional location of implant with the pre-operative design. The 5-year survival rate of implant and prosthesis was recorded, and marginal bone loss around implants and the development of complication were evaluated by radiological and clinical examination respectively. Results: The result on accuracy of CAD/CAM surgical template showed that deviations in neck and apex of implants were (0.78±0.59) and (1.38±0.63) mm respectively, depth deviation was (0.65±0.35) mm and angle deviation was 4.12°±2.77°. The 5-year cumulative survival rate of implants was 98.6%(143/145). In all 145 implants, the prevalence of implant-related biological complication was 4.1%(6/145). The prosthesis-related mechanical complication rate was 57%(13/23). After 5-year function, mean peri-implant bone loss was (0.69±0.35) mm. Conclusions: This 5-year follow-up retrospective study showed that implant-supported fixed prosthesis with the guidance of CAD/CAM surgical template in middle aged and elderly patients could achieve good long-term clinical outcome and patient satisfaction.


Assuntos
Implantes Dentários , Arcada Edêntula , Cirurgia Assistida por Computador , Idoso , Desenho Assistido por Computador , Implantação Dentária Endo-Óssea , Prótese Dentária Fixada por Implante , Feminino , Humanos , Arcada Edêntula/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
3.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(11): 902-907, 2020 Nov 09.
Artigo em Chinês | MEDLINE | ID: mdl-33171566

RESUMO

Objective: To evaluate the influence of the sleeve lengths and implant lengths on accuracy of static computer-assisted implant surgery (sCAIS). Methods: Twenty-eight models of bilateral mandibular single tooth loss were included. Fifty-five implants were placed under the guidance of sCAIS (Straumann Bone Level 4.1 mm×10 mm). According to the height of metal sleeve of static guide plate, 55 implants were divided into 11 groups (free hand group, 1 mm group, 2 mm group, 3 mm group, 4 mm group, 5 mm group, 6 mm group, 7 mm group, 8 mm group, 9 mm group, 10 mm group), with 5 implants in each group. Eight research models were included. Group with 5 mm sleeve guides were used to place implants of different length, (Straumann Bone Level width 4.1 mm, height was 8 mm, 10 mm and 14 mm), 5 implants in each group. Eighteen patients with mandibular single tooth loss were included in the Department of Oral Implantology, Tianjin Stomatological Hospital from October 2018 to June 2019. There were 10 males and 8 females, 18-46(33.7±7.9) years old. A total of 18 implants were implanted and divided into 3 groups (free hand group, 3 mm group and 5 mm group) with 6 implants in each group. Digital software was used to compare the implant positions before and after implantation. Non-parametric Kruskal-Wallis test or one-way ANOVA were used to analyze the results. Results: There was no significant difference in implant vertical deviation between different sleeve height groups (1-10 mm) and free hand group, but the neck deviation in free hand group[(1.04±0.13) mm] was significantly higher than that in different sleeve height groups (1-10 mm) (P<0.05). The tip deviations of free hand group, 1 mm group and 2 mm group [(1.32±0.43), (0.83±0.10) and (0.78±0.11) mm, respectively] was significantly higher than that of 10 mm group [(0.31±0.14) mm](P<0.05). The angle deviation of free hand group and 1 mm group (3.99°±0.85° and 2.59°±0.69°), respectively] was significantly higher than that of 10 mm group (0.61°±0.03°) (P<0.05). The tip deviations of implants in the 14 mm group [(0.83±0.22) mm] was significantly higher than that in the 8 mm and 10 mm groups [(0.44±0.07) and (0.49±0.06) mm, respectively]. Clinical studies showed that there was no significant difference in neck deviation, tip deviation and angle deviation between 3 mm group and 5 mm group (P>0.05), but deviations were significantly lower than those in free hand group (P<0.05). Conclusions: The length of the sleeves has significant influence on the accuracy of the surgical guide. There was no significant difference in accuracy of the implant guide with 3 mm or 5 mm metal sleeves. The vitro study has some limitations and needs further systematic research.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Perda de Dente , Adolescente , Adulto , Desenho Assistido por Computador , Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endo-Óssea , Feminino , Humanos , Imageamento Tridimensional , Masculino , Mandíbula/cirurgia , Pessoa de Meia-Idade , Adulto Jovem
4.
Am J Orthod Dentofacial Orthop ; 158(5): 759-766, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33131565

RESUMO

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.


Assuntos
Técnica de Moldagem Odontológica , Saliva , Desenho Assistido por Computador , Modelos Dentários , Humanos , Imageamento Tridimensional
5.
Orthod Fr ; 91(1-2): 93-99, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33146138

RESUMO

Our relationship to digital technologies will be a determining factor in building our identity as 21st century orthodontists. The digital workflow used in orthodontics can be summarized in four successive phases: diagnosis, treatment planning, computer Aid Manufacturing, therapeutic follow-up. According to Professor Stanislas Dehaene, cognitive neuroscience has identified four criteria on which learning success depends. Attention, active engagement, feedback and consolidation. Our article demonstrates that a good organization of the digital workflow, thought upstream and coherent, allows the practitioner to strengthen his learning from each treated clinical case by potentiating the four criteria of learning. This design which is a real challenge is part of an increase strategy.


Assuntos
Desenho Assistido por Computador , Planejamento de Prótese Dentária , Fluxo de Trabalho
6.
Swiss Dent J ; 130(11): 887-892, 2020 11 09.
Artigo em Alemão | MEDLINE | ID: mdl-33161691

RESUMO

The aim of this case report was to introduce the clinical use of a prosthetic soft tissue level implant and a completely digitized workflow for the production of an individualized suprastructure fixated on prosthetic implants for orthodontic anchorage rein­forcement. A prosthetic soft tissue level implant was placed in the palatal region for orthodontic anchorage reinforcement. Based on an intraoral optical scan taken after implant osseointegration, the orthodontic suprastructure was manufactured entirely by means of computer­aided design and manufacturing (CAD/CAM). The individualized suprastructure was subsequently loaded in direct manner. The prosthetic implant was then re­moved in a non­invasive manner, similar to palatal implants.The analysis included clinical and laboratory fabrication steps. The placement of prosthetic implant in the palatal region proved to be a painless, easy and fast procedure, and provided absolute anchorage during the entire intended orthodontic treatment. Its non­invasive removal did not cause any adverse patient reactions. The digitally constructed suprastructure did not require any chairside adaptation at delivery and was suc­cessfully used for the intended orthodontic treatment.The reported case presents the successful placement, loading and removal of a prosthetic soft tissue level implant for ortho­dontic anchorage use in the palatal region. The described digital and model­free workflow provides a feasible and streamlined treatment modality for the fabrication of individualized ortho­dontic suprastructures by means of CAD/CAM for the use as or­thodontic anchorage reinforcement. This proof of principle should be substantiated with further larger­scaled investigations.


Assuntos
Implantes Dentários , Desenho Assistido por Computador , Humanos , Osseointegração , Fluxo de Trabalho
7.
Indian J Dent Res ; 31(4): 537-545, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33107453

RESUMO

Purpose of the Study: To comparatively evaluate the wear resistance of two different posterior indirect restorative materials against human enamel. Materials and Methods: Two different posterior indirect restorative materials of ten in each Group-I (Monolithic zirconia) (n = 10) and Group-II (Cast cobalt chromium) (n = 10) were formed into disc and used as a substrate for the wear test. Freshly extracted mandibular first premolars were used as a pin (antagonist) (n = 20). Pin-on-disc wear testing machine was used to simulate the masticatory parameters and evaluation of the wear parameters was done after 1,20,000 cycles, with load of 40N for specific duration. Data related to wear testing procedure were tabulated and evaluated. Results were statistically analyzed using Mann-Whitney test and Wilcoxon signed rank test. Results: Mean surface roughness value (Ra value) obtained for Group-I disc test samples showed no statistical significance (P value < 0.05). Mean wear rate value of test disc samples was statistically significant between Group-I and Group-II (P value < 0.05). Mean surface roughness value was statistically significant between Groups-I and II before and after wear test (P value < 0.05). Conclusion: From the results obtained, it was found that the Group-I (Monolithic zirconia) exhibited higher wear resistance than Group-II (cast cobalt chromium) and causes less wear to the opposing enamel antagonist.


Assuntos
Ligas de Cromo , Porcelana Dentária , Desenho Assistido por Computador , Esmalte Dentário , Humanos , Teste de Materiais , Propriedades de Superfície , Zircônio
8.
Sci Rep ; 10(1): 17806, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-33082473

RESUMO

SARS-CoV-2 is a newly emergent coronavirus, which has adversely impacted human health and has led to the COVID-19 pandemic. There is an unmet need to develop therapies against SARS-CoV-2 due to its severity and lack of treatment options. A promising approach to combat COVID-19 is through the neutralization of SARS-CoV-2 by therapeutic antibodies. Previously, we described a strategy to rapidly identify and generate llama nanobodies (VHH) from naïve and synthetic humanized VHH phage libraries that specifically bind the S1 SARS-CoV-2 spike protein, and block the interaction with the human ACE2 receptor. In this study we used computer-aided design to construct multi-specific VHH antibodies fused to human IgG1 Fc domains based on the epitope predictions for leading VHHs. The resulting tri-specific VHH-Fc antibodies show more potent S1 binding, S1/ACE2 blocking, and SARS-CoV-2 pseudovirus neutralization than the bi-specific VHH-Fcs or combination of individual monoclonal VHH-Fcs. Furthermore, protein stability analysis of the VHH-Fcs shows favorable developability features, which enable them to be quickly and successfully developed into therapeutics against COVID-19.


Assuntos
Betacoronavirus/metabolismo , Anticorpos de Domínio Único/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Sequência de Aminoácidos , Reações Antígeno-Anticorpo , Betacoronavirus/isolamento & purificação , Sítios de Ligação , Linhagem Celular , Desenho Assistido por Computador , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Epitopos/química , Epitopos/imunologia , Humanos , Fragmentos Fc das Imunoglobulinas/genética , Fragmentos Fc das Imunoglobulinas/metabolismo , Simulação de Acoplamento Molecular , Mutagênese Sítio-Dirigida , Testes de Neutralização , Pandemias , Biblioteca de Peptídeos , Peptidil Dipeptidase A/química , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Estabilidade Proteica , Anticorpos de Domínio Único/genética , Anticorpos de Domínio Único/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo
9.
Int J Esthet Dent ; 15(4): 374-389, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33089255

RESUMO

This article describes a novel concept for treatment planning and execution in the digital era. The aim of the presented workflow was to design, plan, communicate, perform, fabricate, deliver, and maintain a smile makeover restoration entirely through digital technology. The interdisciplinary treatment plan is described from the planning through the diagnostic mock-up to the final restoration. In digital designing, the dental morphology and tooth shape seen by the clinician and technician are interpreted by the computer as a 3D geometric mathematic model. Controlling the geometry provides freedom for the clinician to develop a restorative digital plan that can be followed throughout the patient's treatment. Moreover, new ceramic materials used with computer-assisted techniques have considerably broadened the choices for dental teams and have enhanced the results that can be achieved.


Assuntos
Dente , Fluxo de Trabalho , Cerâmica , Desenho Assistido por Computador , Humanos , Sorriso
10.
Int J Esthet Dent ; 15(4): 402-426, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33089257

RESUMO

This article outlines the prosthetic concepts in the management of implants in the esthetic zone with a view to achieving optimal long-term esthetics and stability. The emphasis is on the understanding and application of the biologic factors and dental technology that influence treatment outcomes. The authors examine the exciting new world of digitalization of dental procedures that has transformed esthetic dentistry, dental technology, and surgery. The digital workflow makes it possible to attain excellence in many kinds of dental restorations, providing high quality while maintaining a very natural-looking appearance. The newest developments in the field of digital systems allow for greater predictability and precision of results as well as more accuracy, which in turn allows for better design quality. The duration of dental treatment and dental technology has also been reduced due to digitalization. Transitioning from an analog to a digital workflow requires a paradigm shift. The techniques to improve the daily workflow in practice and in the dental laboratory integrate advanced CAD/CAM technologies, combining 3D-printed models and high-end esthetic dental restorations in ceramics. An interdisciplinary approach, detailed in this article, is key to optimal case management.


Assuntos
Dente , Fluxo de Trabalho , Desenho Assistido por Computador , Planejamento de Prótese Dentária , Estética
11.
Shanghai Kou Qiang Yi Xue ; 29(4): 445-448, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-33089300

RESUMO

PURPOSE: The aim of this study was to assess and compare patient satisfaction and time required between silicon rubber impression and intraoral scanning impression. METHODS: Six undergraduates participated in this study. silicon rubber impression and intraoral scanning impression were taken, the time required to obtain the impressions and the scores of visual analog scale(VAS) were recorded. SPSS 23.0 software package was used for statistical analysis. RESULTS: The time and patients satisfaction of silicon rubber impression were better than intraoral scanning impressions, and there were significant differences between the two groups(P<0.05). CONCLUSIONS: Using silicon rubber impression, the patient experience is better. To use intraoral scanning impression technology, dentists should be more skilled. With the role-playing method,dental interns can learn the operation key points and precautions of different impression-taking methods even better.


Assuntos
Borracha , Silício , Desenho Assistido por Computador , Técnica de Moldagem Odontológica , Humanos , Cintilografia
12.
Compend Contin Educ Dent ; 41(9): e5-e9, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33001661

RESUMO

This article describes the case of a partially edentulous patient who had undergone template-guided implant placement and was treated using a triple digital scanning protocol that allowed for CAD/CAM prosthodontic rehabilitation in a complete digital workflow. At the impression appointment, the provisional implant-supported screw-retained prosthesis was digitally scanned both intraorally (first scan) and, after removal, extraorally (second scan). After the second scan, scan bodies were placed intraorally and an implant-level digital impression was taken (third scan). The three standard tessellation language (STL) files derived from the three digital scans were imported in a CAD software and superimposed into one file that contained all of the information from the implant 3D position, prosthesis contours, and transmucosal part of the peri-implant soft tissues. The superimposition of the three STL files led to one master file to serve as a blueprint for the definitive prosthesis. The definitive monolithic zirconia prosthesis was CAM copy-milled, externally stained, and inserted. The patient was satisfied with both the esthetic and functional outcome and the minimally invasive, time-efficient, two-visit restorative protocol. In summary, this case report illustrates a technique for a complete digital workflow in an implant rehabilitation for the replacement of multiple missing teeth in the esthetic zone in two visits.


Assuntos
Implantes Dentários , Fluxo de Trabalho , Desenho Assistido por Computador , Prótese Dentária Fixada por Implante , Estética Dentária , Humanos
13.
Am J Dent ; 33(5): 243-247, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33017526

RESUMO

PURPOSE: Concurrently with the growing interest in CAD-CAM systems, several new materials of different chemical nature have become available. As an alternative to ceramics, numerous polymer-based materials have recently been proposed for permanent prosthetic restorations. Aim of this study was to test the CAD-CAM polymer-based materials available on the market, comparing mean flexural strength, Weibull characteristic strength and Weibull modulus. METHODS: Seven types of polymer-based blocks were tested: Lava Ultimate, 3M; Brilliant Crios, Coltene; Cerasmart, GC; Block HC, Shofu; Katana Avencia, Noritake; Grandio Blocs, Voco; Tetric CAD, and Ivoclar-Vivadent. Specimens were cut out from blocks, finished, polished, and tested in a three-point bending test apparatus until failure (n=30). Flexural strength, Weibull characteristic strength, and Weibull modulus were calculated. Flexural strength data were statistically analyzed. ANOVA on Ranks was applied, followed by the Dunn's test for post hoc comparisons (P= 0.05). RESULTS: Flexural strength values (MPa) were measured (mean±standard deviation). Different letters in parentheses label statistically significant differences: Grandio Blocs 266±24(a), Brilliant Crios 259±21(ab); Tetric CAD 254±15(ab); Katana Avencia 241±29(bc); Cerasmart 221±24(cd); Lava Ultimate 196±23(de); Block HC 139±10(e). All the tested materials had flexural strengths greater than 100 MPa, thereby satisfying the requirements of ISO standards for polymer-based materials. For all the tested materials the Weibull characteristic strength was greater than 100 MPa. Weibull modulus ranged between 21.20 (Tetric CAD) and 9.09 (Katana Avencia). CLINICAL SIGNIFICANCE: Even though all the CAD-CAM polymer-based materials marketed in blocks tested in the present study satisfy the requirements of ISO standard for polymer-based materials, their flexural resistance differs significantly. The data presented in the study may be helpful to clinicians for selecting the most appropriate materials for each clinical case.


Assuntos
Resistência à Flexão , Polímeros , Desenho Assistido por Computador , Materiais Dentários , Teste de Materiais
14.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(5): 964-970, 2020 Oct 18.
Artigo em Chinês | MEDLINE | ID: mdl-33047738

RESUMO

OBJECTIVE: To evaluate the digital workflow coupling conic retention for the immediate restoration of adjacent posterior implants. METHODS: The patients with adjacent teeth missing in the posterior jaw seeking for implant restoration in the Department of Implantology, Peking University School and Hospital of Stomatology from March, 2017 to February, 2018 were recruited. After implant placement and commercial conic retention coping delivery, the patient had an intraoral scan for digital impression, and the computer-assisted design/computer-assisted manufacturing (CAD/CAM) technology was used for the fabrication of the immediate splinted prosthesis, which was made of polymethyl methacrylate (PMMA) and loaded immediately after delivery. Six months later, all the temporary prostheses were replaced by the permanent ones made of monolithic zirconia with CAD/CAM technology as well. The parallel periapical films were taken for the temporary and permanent prostheses post-delivery. The clinical effect of this workflow was evaluated by indices including the survival rates of implants and prostheses, the change of marginal bone level, and the implant-related and prosthesis-related complications; before the final restoration, the Visual Analogue Score (VAS) was used to evaluate the satisfaction of the patients. RESULTS: Ten patients (4 males and 6 females, 55.5 years old for average) were recruited. Totally 34 implants were placed; 14 prostheses were fabricated, temporary and permanent, respectively. After an observation period from 4 to 14 months, the survival rate for implants and prostheses were both 100%; the marginal bone level of the implants were (1.06±0.97) mm and (0.96±0.82) mm, immediate post-operation and 6 months later, respectively. The difference was not statistically significant (P>0.05). Neither implant- nor prostheses- related complications were observed. And the VAS of the patients' satisfaction was 87.2. CONCLUSION: For the adjacent posterior implants, the immediate prostheses manufactured by digital workflow, coupling conic retention, were clinically feasible and patient-satisfactory.


Assuntos
Desenho Assistido por Computador , Fluxo de Trabalho , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Próteses e Implantes , Implantação de Prótese
15.
J Esthet Restor Dent ; 32(7): 726-733, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32886852

RESUMO

OBJECTIVE: To evaluate the microtensile bond strength of four dental computer-aided design/computer-aided manufactured (CAD/CAM) ceramics after application of four different surface treatments. MATERIALS AND METHODS: Four dental CAD/CAM ceramics were tested: feldspathic ceramic (VITABLOCKS-Mark II), polymer-infiltrated ceramic network (VITA ENAMIC), zirconia-reinforced lithium silicate (VITA SUPRINITY), and yttria-stabilized zirconia (VITA YZ T). Four surface treatments were applied: no treatment, 5% hydrofluoric acid-etching, airborne particle abrasion, and tribochemical silica coating. The ceramic blocks were repaired with nanohybrid composite (Tetric N-Collection). Sixteen test groups of 12 specimens were prepared. After thermocycling, microtensile bond testing was performed. The microtensile strengths values were statistically analyzed using two-way analysis of variance and Tukey's post-hoc test. RESULTS: Repaired feldspathic and resin polymer-infiltrated ceramic network ceramics demonstrated superior microtensile bond strengths compared to zirconia-reinforced lithium silicate and yttria-stabilized zirconia. Etched feldspathic and polymer-infiltrated ceramic network ceramics had higher bond strength than the untreated groups. Surface treatments did not affect the bond strength of zirconia-reinforced lithium silicate and yttria-stabilized zirconia with the exception of etching, which reduced the bond strength of yttria-stabilized zirconia. CONCLUSION: Feldspathic ceramic and polymer-infiltrated ceramic network were repaired with dental composite after surface etching with hydrofluoric acid. Repair of zirconia-reinforced lithium silicate and yttria-stabilized zirconia did not demonstrate promising results. CLINICAL SIGNIFICANCE: Repair of feldspathic ceramic and polymer-infiltrated ceramic network restorations may be a cost-effective means to promote the longevity of dental restorations. However, zirconia and zirconia-reinforced lithium disilicate restorations do not offer such an option.


Assuntos
Colagem Dentária , Cerâmica , Desenho Assistido por Computador , Porcelana Dentária , Análise do Estresse Dentário , Teste de Materiais , Cimentos de Resina , Propriedades de Superfície , Zircônio
16.
Oper Dent ; 45(6): 664-676, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32997740

RESUMO

CLINICAL RELEVANCE: When a resin nanoceramic inlay is cemented using self-adhesive cement, a universal dentin adhesive can be applied to the prepared cavity. The application of the adhesive before self-adhesive cement placement provides similar or better interfacial adaptation than without the adhesive. SUMMARY: Purpose: The first objective of this study was to determine whether the luting material used for computer-aided design and computer-aided manufacture resin nanoceramic inlays affected interfacial adaptation. The second objective was to investigate whether application of a universal dentin adhesive before cementation affected interfacial adaptation. The final objective was to compare the inlay-side and dentin-side interfaces in the cement space.Methods and Materials: Seventy-four class I cavities were prepared on extracted human third molars. Cavities were optically scanned, and resin nanoceramic inlays were milled using Lava Ultimate blocks (3M ESPE). For the control groups, the fabricated inlays were cemented using Panavia V5 (Kuraray Noritake) or FujiCem 2 (GC). For the experimental groups, the teeth were randomly divided into groups I and II. Group I contained four subgroups using different luting materials; in all subgroups, the inlays were cemented and dual cured without pretreatment. Group II contained six subgroups in which inlays were cemented and dual cured after application of a universal dentin adhesive. After thermocycling, interfacial adaptation was measured using swept-source optical coherence tomography (SS-OCT) imaging and statistically compared among groups.Results: Interfacial adaptation was different depending on the luting material used (p<0.05). After application of a universal adhesive, some subgroups showed improved interfacial adaptation (p<0.05). In the comparison of inlay-side and dentin-side interfaces, no difference was found in interfacial adaptation (p>0.05).Conclusions: Interfacial adaptation for resin nanoceramic inlays differed with luting material. For some self-adhesive cements, application of a universal adhesive before cementation improved interfacial adaptation.


Assuntos
Restaurações Intracoronárias , Tomografia de Coerência Óptica , Resinas Compostas , Desenho Assistido por Computador , Preparo da Cavidade Dentária , Porcelana Dentária , Humanos , Teste de Materiais , Cimentos de Resina
17.
Artigo em Inglês | MEDLINE | ID: mdl-32926002

RESUMO

Preoperative planning and implant placement can be optimized using implant planning software followed by the creation of an individual surgical guide. Alongside clinical advantages of using guided surgery, a variability in the accuracy of implant position has been reported. This variability is even more substantial in fully edentulous patients and attributed to errors from intrinsic and extrinsic sources. The aim of this paper is to discuss the potential process errors and present two digital data registration protocols to be implemented in fully edentulous patients. The suggested protocols are aimed to improve accuracy of data acquisition, data superimposition on planning software, and therefore treatment outcome as well.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Desenho Assistido por Computador , Implantação Dentária Endo-Óssea , Prótese Dentária Fixada por Implante , Humanos , Resultado do Tratamento
18.
Quintessence Int ; 51(9): 776-779, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32901238

RESUMO

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.


Assuntos
Modelos Dentários , Fluxo de Trabalho , Desenho Assistido por Computador , Humanos , Maxila , Software
19.
J Oral Sci ; 62(4): 420-422, 2020 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-32908079

RESUMO

This study compared the mechanical properties and molecular distribution of a polymethyl methacrylate (PMMA) block (Dry) with specimens that were fabricated by a conventional method and cured in a wet environment (Control). Two specimen types were fabricated with heat-curing denture base resin. Dry specimens were polymerized at high pressure and in a dry system, while Control specimens were polymerized with a heat-curing method, in accordance with the manufacturer's recommended procedures. Specimens from each group were evaluated for three-point bending, water sorption and solubility, and color change, and by gel permeation chromatography (GPC). Mean values for the flexural strengths and moduli of the Dry specimens were significantly higher than those of the Control specimens (P > 0.05). Water sorption and discoloration values of the Dry group were significantly lower than those of the Control group. Mean weight-average molecular weights of the Dry group were higher than those of the Control group. As compared with the conventional method, the present method of fabricating PMMA blocks under high pressure yields superior mechanical properties for the denture base.


Assuntos
Desenho Assistido por Computador , Polimetil Metacrilato , Bases de Dentadura , Dentaduras , Teste de Materiais , Estresse Mecânico , Propriedades de Superfície
20.
Nan Fang Yi Ke Da Xue Xue Bao ; 40(8): 1220-1224, 2020 Aug 30.
Artigo em Chinês | MEDLINE | ID: mdl-32895187

RESUMO

Orthopedic 3D printed surgical navigational template is an instrument that is prepared by 3D reconstruction based on preoperative radiological data of the patient using computer-aided design (CAD) and 3D printing techniques. The 3D printed navigational template allows accurate intra-operative assessment of the relative spatial distance, angular relationship, direction and depth. The application of 3D printed navigational template technique in orthopedics surgeries achieves the conversion of preoperative planning from 2/3D graphics to 3D models, and provides a new method for individualized and precise treatment. Herein we review the evolution, clinical application, and basic classification of 3D printed navigation template technique, analyze its advantages and disadvantages, and discuss the current problems and the future development of this technique.


Assuntos
Procedimentos Ortopédicos , Desenho Assistido por Computador , Humanos , Impressão Tridimensional
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