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1.
Braz. j. oral sci ; 21: e224265, jan.-dez. 2022. tab
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1354719

RESUMO

Aim: This study assessed the color and translucency stability of a polymer infiltrated ceramic network (PICN) and compared it with a resin composite (RC) and a feldspathic ceramic (FEL). Methods: Disc-shaped samples of a PICN (Vita Enamic), a feldspathic ceramic (Vitablocks Mark II), and a resin composite (Brava block) were prepared from CAD/CAM blocks. PICN and RC surfaces were finished with a sequence of polishing discs and diamond paste. FEL samples received a glaze layer. The samples were subjected to 30-min immersions in red wine twice a day for 30 days. CIEL*a*b* coordinates were assessed with a spectrophotometer at baseline and after 15 and 30 days of immersion. Color alteration (ΔE00) and translucency parameter (TP00) were calculated with CIEDE2000. Average roughness was measured before the staining procedures. Color difference and translucency data were analyzed with repeated-measures ANOVA and Tukey's tests. Roughness was analyzed with the Kruskal-Wallis test. Results: Roughness was similar among the experimental groups. All materials had their color alteration significantly increased from 15 to 30 days of staining. PICN reached an intermediate ΔE00 between FEL and RC at 15 days. PICN revealed a color alteration as high as the composite after 30 days. No statistical difference was observed regarding translucency. Conclusion: PICN was not as color stable as the feldspathic ceramic at the end of the study. Its color alteration was comparable to the resin composite when exposed to red wine. However, the translucency of the tested materials was stable throughout the 30-day staining


Assuntos
Propriedades de Superfície , Teste de Materiais , Cerâmica , Desenho Assistido por Computador , Cor , Resinas Compostas
2.
Braz. j. oral sci ; 21: e228852, jan.-dez. 2022. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1392917

RESUMO

Aim: To evaluate the occlusal and internal marginal adaptation of inlay restorations made of different materials, using CAD-CAM. Methods: Preparations were made for MOD inlays of one-third intercuspal width and 4 mm depth in 30 third human molars. The teeth were restored using CAD-CAM materials (n=10) of nanoceramic resin (Lava Ultimate), polymer-infiltrated ceramic network (VITA ENAMIC), or lithium disilicate glass-ceramic (IPS e.max CAD). The specimens were cemented with dual resin cement and sectioned at the center of the restoration, after which the two halves were evaluated, and photographed The occlusal and internal discrepancy (µm) was determined at five points: cavosurface angle of the occlusal-facial wall (CA-O); center of the facial wall (FW); faciopulpal angle (FPA); center of the pulpal wall (PW); and center of the lingual wall (LW). The data were submitted to the Kruskal-Wallis and the Dunn tests (α=0.05). Results: No difference was observed among the materials regarding the occlusal discrepancy at the CA-O, FPA, or PW internal points. The e.max CAD measurement at FW showed larger internal discrepancy than that of Lava (p=0.02). The internal discrepancy at LW was greater for e.max CAD than VITA ENAMIC (p=0.02). Conclusion: Lithium disilicate glass-ceramic presented greater internal discrepancy in relation to the surrounding walls of the inlay preparations


Assuntos
Cerâmica , Desenho Assistido por Computador , Adaptação Marginal Dentária , Materiais Dentários , Restaurações Intracoronárias
3.
Biomed Res Int ; 2022: 6254551, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36072474

RESUMO

Teeth loosening are caused by insufficient supporting tissue, inflammation of periodontal tissue, or occlusal trauma, which is one of the main clinical symptoms of periodontitis. A digital technique for fabricating resin-bonded splinting fixed partial dentures (S-FPDs) is presented. It restores the missing mandible anterior teeth and splints the adjacent periodontally mobile teeth of the patient at the same time. The S-FPDs is designed and fabricated by computer-aided design and computer-aided manufacturing (CAD/CAM) technology with flexible PMMA material. The workflow is straightforward, convenient, and accurate. Meanwhile, the restoration can meet the esthetic requirements and help with the stability of adjacent loosening natural teeth spontaneously. It could be considered a medium-term provisional restorative treatment option, but further controlled investigations still be needed.


Assuntos
Prótese Adesiva , Perda de Dente , Desenho Assistido por Computador , Planejamento de Dentadura , Humanos , Mandíbula , Contenções Periodontais
4.
J Mech Behav Biomed Mater ; 134: 105417, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36049370

RESUMO

OBJECTIVES: To evaluate the effect of in-lab simulation of CAD/CAM grinding and intaglio surface treatments on the surface characteristics (topography and roughness) and fatigue behavior of adhesively luted 4YSZ simplified restorations. METHODS: Ceramic discs (Ø = 10 mm, thickness = 1 mm) were randomly allocated into 6 groups considering: "In-lab simulation of CAD/CAM grinding" (ground or polished) and "intaglio surface treatments": Ctrl (without surface treatment), AlOx (aluminum oxide air abrasion) or GLZ (glaze spray application). The surface roughness of all samples was measured, the treated discs received a ceramic primer, were luted with resin cement onto a dentin analogue material (woven glass-reinforced epoxy resin) and tested under a cyclic fatigue test (step-stress approach, n = 15; 1.4 Hz, 10,000 cycles/step, step-size of 100N starting at 200N until failure). A complementary analysis was performed to corroborate the findings in the fatigue test that the glaze fill defects increase the mechanical properties of the ceramic. To do so, bars (n= 10; 1.0 × 1.0 × 12 mm; considering the groups: N-ID: non-indented; ID: indented; ID-GLZ: indented plus glaze spray application) were indented in a vickers hardness tester to produce a crack pattern, treated with glaze or not, and then submitted to flexural strength tests (FS). Fractographic and topographic analysis were performed. RESULTS: In-lab simulation of CAD/CAM grinding decreased the fatigue failure load of the 4YSZ ceramic when comparing polished and ground groups, regardless of surface treatment. GLZ induced better fatigue performance compared to the air abrasion, regardless of the grinding condition (ground or polished surface). The results of the flexural strength test corroborated the findings in the fatigue test, as the ID-GLZ group presented superior FS than the ID group, however both had inferior FS than N-ID. There is an inverse association between roughness and fatigue failure load, as the higher the surface roughness, the lower the fatigue failure load. Failures in the fatigue and flexural strength tests started from the face subjected to tensile stresses. CONCLUSION: In-lab simulation of CAD/CAM grinding had a detrimental effect on the fatigue behavior of 4YSZ and glaze spray induced better 4YSZ performance compared to the air abrasion. The intaglio surface treatments differently influenced the 4YSZ fatigue performance, however, only glaze spray can reverse the damage caused by the grinding.


Assuntos
Cerâmica , Desenho Assistido por Computador , Porcelana Dentária , Análise do Estresse Dentário , Teste de Materiais , Propriedades de Superfície , Suporte de Carga , Zircônio
5.
Am J Orthod Dentofacial Orthop ; 162(3): 403-409, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36049869

RESUMO

INTRODUCTION: Presurgical infant orthopedics was introduced as an interceptive approach for treating cleft lip and/or palate (CLP). This study aimed to evaluate the intraoral digital impression technique as a viable alternative to conventional impression in infants with unilateral CLP. METHODS: Trios 3-Shape scanner (3Shape, Copenhagen, Denmark) was used for intraoral scanning of the infants' maxillary arches to provide a direct digital scan (DDS). In addition, conventional impressions of the same patients were taken in a hospital setting, and the resultant stone models were digitized using the same scanner to create an indirect digital scan (IDS). Both scans (DDS and IDS) were exported in stereolithography format, and the resultant stereolithography files were imported into computer-assisted-design software (Exocad DentalCAD; exocad GmbH, Darmstadt, Germany) for 3-dimensional surface model superimposition. Differences between the 2 surfaces were quantified in millimeters and visually displayed by a color map. RESULTS: Three-dimensional surface model superimposition of the DDS and IDS scans showed an excellent agreement between both approaches, in which differences ranged from 0.01 mm to 0.1 mm CONCLUSIONS: Intraoral direct digital impression in infants with unilateral CLP is a safe, accurate, and time-efficient technique, which can be a viable alternative to conventional impression. This will aid in overcoming the challenges and complications that are frequently associated with using conventional impressions in infants with unilateral CLP, thus reducing the burden of care not only on the patients' families but also on the care providers.


Assuntos
Fenda Labial , Fissura Palatina , Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Desenho Assistido por Computador , Técnica de Moldagem Odontológica , Humanos , Imageamento Tridimensional/métodos , Lactente , Modelos Dentários
6.
Sci Rep ; 12(1): 14864, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36050386

RESUMO

In the manufacturing industry, all things related to a product manufactured are generated and managed with a three-dimensional (3D) computer-aided design (CAD) system. CAD models created in a 3D CAD system are represented as geometric and topological information for exchange between different CAD systems. Although 3D CAD models are easy to use for product design, it is not suitable for direct use in manufacturing since information on machining features is absent. This study proposes a novel deep learning model to recognize machining features from a 3D CAD model and detect feature areas using gradient-weighted class activation mapping (Grad-CAM). To train the deep learning networks, we construct a dataset consisting of single and multi-feature. Our networks comprised of 12 layers classified the machining features with high accuracy of 98.81% on generated datasets. In addition, we estimated the area of the machining feature by applying Grad-CAM to the trained model. The deep learning model for machining feature recognition can be utilized in various fields such as 3D model simplification, computer-aided engineering, mechanical part retrieval, and assembly component identification.


Assuntos
Desenho Assistido por Computador , Redes Neurais de Computação
7.
Molecules ; 27(17)2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36080477

RESUMO

The Rat Sarcoma (RAS) family (NRAS, HRAS, and KRAS) is endowed with GTPase activity to regulate various signaling pathways in ubiquitous animal cells. As proto-oncogenes, RAS mutations can maintain activation, leading to the growth and proliferation of abnormal cells and the development of a variety of human cancers. For the fight against tumors, the discovery of RAS-targeted drugs is of high significance. On the one hand, the structural properties of the RAS protein make it difficult to find inhibitors specifically targeted to it. On the other hand, targeting other molecules in the RAS signaling pathway often leads to severe tissue toxicities due to the lack of disease specificity. However, computer-aided drug design (CADD) can help solve the above problems. As an interdisciplinary approach that combines computational biology with medicinal chemistry, CADD has brought a variety of advances and numerous benefits to drug design, such as the rapid identification of new targets and discovery of new drugs. Based on an overview of RAS features and the history of inhibitor discovery, this review provides insight into the application of mainstream CADD methods to RAS drug design.


Assuntos
Desenho Assistido por Computador , Neoplasias , Animais , Biologia Computacional , Desenho de Fármacos , Humanos , Neoplasias/patologia , Proteínas/química
8.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 57(9): 895-898, 2022 Sep 09.
Artigo em Chinês | MEDLINE | ID: mdl-36097934

RESUMO

Based on evidence-based clinical and material researches, the Society of Prosthodontics, Chinese Stomatological Association organized a panel of experts to write a recommended application guideline via in-depth discussion and literature reviewing. This guideline formulates the standardized operation procedures for the clinical usage of chairside computer aided design and computer aided manufacturing (CAD/CAM) rehabilitation with resin-ceramic composites, aiming at guiding and specifying this clinical technique. This guideline will help to improve the quality, the clinical efficacy, and the long-term success rate of chairside CAD/CAM rehabilitation with resin-ceramic composites via standardizing this restoration technique. At the same time, this guideline will contribute to the clinical promotion of this technique.


Assuntos
Desenho Assistido por Computador , Planejamento de Prótese Dentária , Cerâmica , Resinas Compostas , Prostodontia
9.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 57(9): 927-931, 2022 Sep 09.
Artigo em Chinês | MEDLINE | ID: mdl-36097939

RESUMO

Objective: To compare the accuracy and retention of denture bases fabricated by injection molding, milling, and three-dimensional (3D) printing fabricating, in order to provide some references for clinical practice. Methods: A maxillary edentulous jaw model made was used to duplicated 10 working casts. The casts were numbered and scanned. The wax pattern was designed by digital ways and conventional methods and then the denture bases were fabricated by injection molding, milling, and 3D printing. The tissue surface of experimental denture base was obtained using a dental laboratory scanner. The deviation between the tissue surface of the fabricated denture bases and the working model was evaluated. A digital force gauge was used to measure the traction force. Results: The milling group [(0.076±0.026) mm] was more accurate than the 3D printing group [(0.117±0.041) mm] (P<0.05) and the injection group [(0.120± 0.025) mm] (P<0.05). The accuracy of 3D printing group and that of injection group were not statistically significant (P>0.05). The milling group [(9.55±2.44) N] demonstrated greater retentive force than 3D printing group [(5.19±0.06) N] and injection molding group [(1.52±0.52) N] (P<0.05). Conclusions: The denture base fabricated by milling was more accurate and showed the greatest retentive force than the other groups. And 3D printing group showed better retentive force than the injection molding group. Both digital manufacturing methods can meet the requirements of clinical application.


Assuntos
Bases de Dentadura , Arcada Edêntula , Desenho Assistido por Computador , Humanos , Maxila , Impressão Tridimensional
10.
Shanghai Kou Qiang Yi Xue ; 31(2): 221-224, 2022 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-36110085

RESUMO

PURPOSE: To evaluate the teaching effect of making custom trays via CAD in dental postgraduates. METHODS: Twenty-seven dental postgraduates from first to third grade at the School and Hospital of Stomatology, Tongji University, Shanghai were given an informed consent to explain and request participation in the study. First, a lecture about the theory and process of fabricating custom tray via traditional hand-made method and CAD technique was given, then the students fabricated custom trays via the two methods and completed an online survey. The working time, margin extension and students' preference were analyzed with SPSS 22.0 software package. RESULTS: The working time was shorter, the margin extension was superior, and students' preference was higher via CAD than traditional method, the difference was significant(P<0.05). CONCLUSIONS: CAD is more conducive to enhance students' understanding of custom tray manufacturing process and relevant theoretical knowledge. It is recommended to integrate digital technology into dental curriculum.


Assuntos
Desenho Assistido por Computador , Técnica de Moldagem Odontológica , China , Humanos , Estudantes
11.
Chin J Dent Res ; 25(3): 215-222, 2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36102891

RESUMO

OBJECTIVE: To evaluate the accuracy of 10 intraoral scanners for single-crown and three-unit preparation models. METHODS: A maxillary partially edentulous model was fabricated. A dental cast scanner was used to obtain standard tessellation language (STL) data. Ten intraoral scanners, namely Trios 2 (TR2; 3Shape, Copenhagen, Denmark), True Definition (TD; 3M, Saint Paul, MN, USA), CEREC AC Omnicam (OM; Dentsply Sirona, Charlotte, NC, USA), Organical Scan Oral (OS; R+K, Berlin, Germany), PlanScan (PS; Planmeca, Helsinki, Finland), DWIOP (DW; Dental Wings, Montreal, Canada), Xianlin (XL; Hangzhou Xianlin, Hangzhou, China), DL-100 (DL; Guangzhou Longcheng, Guangzhou, China), Trios 3 (TR3; 3Shape) and i500 (MD; MEDIT, Seoul, South Korea) were used to obtain stereolithography data as test groups. Trueness, precision and surface accuracy were evaluated by deviation analysis using 3D image processing software. One tooth with a three-unit preparation for each test group was registered with the reference scan data, and the absolute distance from another tooth was calculated as the absolute accuracy. The data were analysed using a Mann-Whitney U test and Dunn-Bonferroni test (α = 0.05). RESULTS: The best trueness, precision and surface accuracy of scanning single crown preparation were recorded with TD (trueness 2.9 µm and precision 1.9 µm) and XL (surface accuracy 20.3 ± 2.9 µm). The best trueness, precision, surface accuracy and absolute accuracy of three-unit preparations were recorded with TD (2.6 µm), XL (1.9 µm), OM (27.1 ± 5.2 µm) and TR3 (79.2 ± 19.6 µm), respectively. There was no statistically significant difference in trueness between single- and multiple-unit preparations for any of the intraoral scanners (P > 0.05). A statistically significant difference in the surface accuracy between single and multiple preparations was found for TR2, TD, OM, DW, XL, DL and MD (P < 0.05). CONCLUSION: The trueness and precision of intraoral scanners for scanning three-unit preparations were nearly the same as those for single-crown preparations; however, with the exception of OS, PS and TR3, the surface accuracy of single-crown preparations was significantly better than that for three-unit preparations.


Assuntos
Técnica de Moldagem Odontológica , Dente , Desenho Assistido por Computador , Coroas , Dentaduras
12.
Sensors (Basel) ; 22(16)2022 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-36015823

RESUMO

Distributed optical fiber sensing technology has been widely applied in the areas of infrastructure health monitoring, national defense security, etc. The long-range high-spatial-resolution Brillouin optical correlation domain analysis (BOCDA) has extensive development and application prospects. In this paper, long-range BOCDAs are introduced and summarized. Several creative methods underpinning measurement range enlargement, including the interval enhancement of the adjacent correlation peak (CP), improvements in the signal-to-noise ratio, and the concurrent interrogation of multiple CPs, are discussed and experimentally verified, respectively. The main drawbacks in the present BOCDA schemes and avenues for future research and development have also been prospected.


Assuntos
Tecnologia de Fibra Óptica , Refratometria , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Transdutores
13.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 39(4): 841-847, 2022 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-36008349

RESUMO

With the development of computer and digital technology, the application of computer-aided technology has become a new trend in the field of oral implant. Computer-guided oral implant surgery has the advantages of being safer and more accurate than traditional implant surgery, and it can truly realize the concept of restoration-oriented implant. However, computer-guided oral implant surgery has various steps which cause deviations accumulation, so that some clinicians remain sceptical about the accuracy of the technology. Currently, due to the lack of a quantitative system for evaluating the accuracy of computer-guided oral implantation, the implant deviation in each step is still inconclusively in the stage of research and debate. The purpose of this paper is to summarize the advantages and disadvantages, research progress, accuracy and influencing factors of computer-guided oral implantation, aiming to provide a reference for improving implant accuracy and guiding clinical design and surgery.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Desenho Assistido por Computador , Computadores , Tomografia Computadorizada de Feixe Cônico , Imageamento Tridimensional , Planejamento de Assistência ao Paciente
14.
J Long Term Eff Med Implants ; 32(4): 39-45, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36017926

RESUMO

Implant design and biomaterial composition are contributing factors in stress distribution throughout the implant body and the surrounding bone. The aim of this study was to evaluate the pattern of stress distribution using four different implant systems based on finite element analysis. This study was conducted using a cone beam computed tomography scan and four implant systems (ITI, SPI, 3i, and IDCAM); mandibular and implant models were constructed by a computer-aided design software (CATIA). Stress distribution under axial, mesio-distal, and combination static loading was assessed using finite element analysis in ABAQUS. The maximum von Mises stress value in dental implants was recorded for IDCAMs and IDCAMm implants considering all types of loading directions; however, these implant models showed the least stress distribution in the surrounding bone. The maximum stress occurred using combination followed by axial and mesio-distal loading. The stress distribution was concentrated, in all designs, at the level of the most coronal portion of the cortical bone. Within the limitations of the present study, it could be assumed that implant design may affect the distribution of stress in the implant body, and it could be used as a strategy to reduce stress concentration in the surrounding bone.


Assuntos
Implantes Dentários , Mandíbula , Fenômenos Biomecânicos , Simulação por Computador , Desenho Assistido por Computador , Planejamento de Prótese Dentária , Análise de Elementos Finitos , Humanos , Mandíbula/diagnóstico por imagem , Próteses e Implantes , Estresse Mecânico
15.
Am J Dent ; 35(4): 167-171, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35986930

RESUMO

PURPOSE: To evaluate the fracture strength of polyetheretherketone (PEEK) single crowns veneered with different materials produced by computer-aided design (CAD)-computer-aided manufacture (CAM) after aging. METHODS: 60 stainless-steel master dies were prepared with a 1 mm-wide deep chamfer. Sixty PEEK frameworks were produced with a CAD-CAM system for the right maxillary first molar tooth on the dies. PEEK frameworks were divided into six groups (n= 10) according to veneering materials (five CAD-CAM materials and a resin composite). Group ZR: monolithic zirconia (Upcera ST-Color); Group EC: lithium disilicate glass-ceramic (IPS e.max CAD); Group LU: resin nano-ceramic (Lava Ultimate); Group VM: feldspathic ceramic (Vitablocs Mark II); Group VS: zirconia-reinforced lithium silicate glass-ceramic (VITA Suprinity); and Group CR: indirect resin composite (Gradia). All samples were subjected to a fracture strength test in a universal test device after thermo-mechanical aging and then the results were analyzed statistically using one-way ANOVA and Tukey's post hoc test. In addition, post-fracture analyses of all samples were performed with a stereomicroscope. RESULTS: The differences in fracture strength values of different veneer materials in single crowns with a PEEK framework were statistically significant (P< 0.05). Fracture strength was highest in Group ZR (1665 N), followed by Groups LU (1440 N), EC (1249 N), CR (918 N), VS (754 N), and VM (655 N). CLINICAL SIGNIFICANCE: PEEK frameworks may have the potential to be used with many veneer materials of different content and properties in fixed partial prostheses.


Assuntos
Implantes Dentários , Resistência à Flexão , Benzofenonas , Cerâmica , Desenho Assistido por Computador , Coroas , Porcelana Dentária , Falha de Restauração Dentária , Análise do Estresse Dentário , Teste de Materiais , Polímeros , Zircônio
16.
Dent Mater ; 38(9): 1532-1546, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35914965

RESUMO

OBJECTIVES: The aim of this study was to investigate the influence of hybrid CAD/CAM-blocks on immortalized human gingival keratinocytes (HGK). METHODS: Samples of two different hybrid CAD/CAM materials [Lava™ Ultimate (3 M); VITA Enamic® (VITA Zahnfabrik)], a composite material [ceram.x® universal (Dentsply Sirona)] and a CAD/CAM ceramic [VITABLOCS® (VITA Zahnfabrik)] were stored in cell culture medium for 72 h to prepare eluates according to ISO-10993-12:2012. HGK were exposed to eluates for 6, 24 and 48 h. Cell monitoring was performed by RTCA iCELLigence™ system. The morphological changes were evaluated using phase contrast imaging. Specific biomarkers of apoptosis and terminal differentiation (Caspase-3, Involucrin) were analyzed semi quantitatively by indirect immunofluorescence (IIF). Protein levels and activation of MAP kinases ERK1/2 (p44/42) were quantified by Western blot. Data were statistically analyzed by unpaired t-test (p < 0.05). RESULTS: Regarding Vita Enamic® and Lava™ Ultimate, results of RTCA iCELLigence™ and Western blots showed no statistically significant differences (p > 0.05) compared to the negative control (HGK in native keratinocyte growth medium). No aberrant expression of Caspase-3 and Involucrin was detected in cells incubated with Vita® Enamic eluates Cells incubated with Lava™ Ultimate showed a higher expression of Involucrin after 24 h of incubation compared to the negative control. Statistically significant differences (p < 0.01) were found between cells incubated with ceram.x® universal and the negative control in RTCA iCELLigence™ assay and in quantitative measurements of Western blots after 6 h against phospho-p44/42 (p = 0.044). Increased expression of Caspase-3 and Involucrin were detected by IIF in cells after incubation with eluates of ceram.x® universal. SIGNIFICANCE: The present data show no significant effect of hybrid materials on analyzed functions of cell behavior. A cytotoxic influence of ceram.x® universal eluates was observed in HGK in terms of a strong modulation of proliferation, morphology and protein expression.


Assuntos
Cerâmica , Desenho Assistido por Computador , Caspase 3/farmacologia , Gengiva , Humanos , Queratinócitos , Teste de Materiais
17.
Med Sci Monit ; 28: e937331, 2022 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-35978528

RESUMO

BACKGROUND We aimed to investigate the clinical effects of resin nanoceramic (RNC) computer-aided design/computer-aided manufacture (CAD/CAM) partial crowns on posterior teeth after root canal treatment over a 3-year period. MATERIAL AND METHODS A total of 132 posterior teeth restored with CAD/CAM partial crowns were placed in 128 patients. The observation group (n=66) was restored with RNC restorations, while the control group received lithium disilicate-based glass ceramic (LDGC) CAD restorations. Using Federation dentaire internationale (FDI) World Dental Federation clinical criteria, 2 calibrated evaluators examined the performance of the restorations at baseline, 6, 12, 18, 24, and 36 months. The Kaplan-Meier method and the log-rank test were adopted to analyze the survival rate. The influence of potential risk factors on the main pattern of failure was studied by univariate Cox regression analysis (alpha=0.05). RESULTS At the 3-year followup, the survival rate of the partial crowns was 83.1% in the RNC group, and 93.5% in the LDGC group (P=0.061). Failures were caused by debonding (66.7%), restoration fracture (26.6%), and tooth fracture (6.7%). No significant differences were found between the 2 materials at 36 months, except for the parameters of "surface luster" (P=0.002) and "occlusal contour and wear" (P=0.009). The RNC group was significantly more likely to debond than the LDGC group (hazard ratio=9.22 [1.17,72.74], P=0.01). CONCLUSIONS RNC CAD/CAM-fabricated partial crowns are a potential clinical alternative for endodontically treated posterior teeth, with a survival rate of 83.1% at the 3-year followup. The main pattern of failure was debonding, which might be influenced by surface pretreatment of the RNC material.


Assuntos
Desenho Assistido por Computador , Coroas , Cerâmica/química , Cerâmica/uso terapêutico , Computadores , Porcelana Dentária , Planejamento de Prótese Dentária , Humanos , Teste de Materiais , Tratamento do Canal Radicular
18.
J Mech Behav Biomed Mater ; 134: 105390, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35917636

RESUMO

PURPOSE: To evaluate the effect of simulated brushing and chemical disinfection on the surface roughness and color stability of CAD-CAM denture base materials and to compare with those of a heat-cured denture base material. MATERIAL AND METHODS: Disk-shaped specimens (Ø 10mm × 2 mm) were prepared from 3 CAD-CAM denture base resins (AvaDent, Ava; Merz M-PM, Merz; Polident d.o.o, Poli) and a heat-cured polymethylmethacrylate resin (Promolux, Conv) (n = 30). After polishing, baseline surface roughness (Ra) and color coordinates were measured. The measurements were repeated after 20000 cycles of simulated brushing, and the specimens were divided into 3 groups according to disinfection protocol (distilled water, 1% sodium hypochlorite (NaOCl), and effervescent tablet) (n = 10). After 9 cleaning cycles over a period of 20 days, Ra and color coordinates were remeasured. Color differences (ΔE00) were calculated by using CIEDE2000 formula. One-way analysis of variance (ANOVA) and pairwise t-tests were used to analyze Ra and ΔE00 data, while repeated measures ANOVA test was used to compare baseline, after brush, and after disinfection Ra values (α = 0.05). RESULTS: Brushing did not affect the Ra values of tested materials (P ≥ .08). Both before and after brushing, Merz and Conv had higher Ra values than Poli and Ava (P < .001). Among disinfectants, effervescent tablet led to the lowest Ra for Merz (P = .003) and the highest Ra for Poli (P ≤ .039). Only NaOCl resulted in significant differences among the Ra of materials (P < .001), as Merz and Conv had higher Ra values than Poli (P ≤ .002). Repeated measures ANOVA revealed that effervescent tablet disinfection of Merz led to lower Ra values than those of baseline and after brushing (P ≤ .042). After brushing, Ava and Conv had higher ΔE00 values compared with Merz and Poli (P ≤ .015). When compared with other disinfection protocols, effervescent tablet led to higher ΔE00 values for Merz and Poli (P < .001). Significant differences were observed among materials when NaOCl was used; Conv had higher ΔE00 values than Ava and Merz (P = .004). CONCLUSIONS: Brushing did not increase the surface roughness of materials. Disinfection protocol's effect on the surface roughness varied. The effect of brushing on the color of materials varied; color of Ava and Conv was affected from brushing more than the other materials. Color stability of materials varied depending on the disinfection protocol. Effervescent tablet caused higher color change with Merz and Poli compared with other disinfectants. NaOCl led to small color change for Poli, Ava, and Merz materials.


Assuntos
Bases de Dentadura , Desinfetantes , Cor , Desenho Assistido por Computador , Desinfecção/métodos , Teste de Materiais , Propriedades de Superfície
19.
Artigo em Inglês | MEDLINE | ID: mdl-36044687

RESUMO

Conventional approaches to full-arch implant dentistry require a verified master model created by luting together impression jigs. This process involves numerous steps and is sometimes prone to errors that require subsequent correction. A novel approach involving an extraoral scanning technique using an Imetric 4D Imaging system demonstrates an alternative for same-day delivery of printed full-arch prosthetics. Advantages include the ability to offer a same-day provisional restoration without needing to verify an analog master cast.


Assuntos
Implantes Dentários , Técnica de Moldagem Odontológica , Desenho Assistido por Computador , Prótese Dentária Fixada por Implante , Humanos
20.
Science ; 377(6609): 975-981, 2022 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-36007025

RESUMO

Biomaterials display microstructures that are geometrically irregular and functionally efficient. Understanding the role of irregularity in determining material properties offers a new path to engineer materials with superior functionalities, such as imperfection insensitivity, enhanced impact absorption, and stress redirection. We uncover fundamental, probabilistic structure-property relationships using a growth-inspired program that evokes the formation of stochastic architectures in natural systems. This virtual growth program imposes a set of local rules on a limited number of basic elements. It generates materials that exhibit a large variation in functional properties starting from very limited initial resources, which echoes the diversity of biological systems. We identify basic rules to control mechanical properties by independently varying the microstructure's topology and geometry in a general, graph-based representation of irregular materials.


Assuntos
Materiais Biocompatíveis , Desenho Assistido por Computador , Engenharia , Materiais Biocompatíveis/química , Engenharia/métodos
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