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1.
J Prosthodont ; 33(2): 157-163, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36740784

RESUMO

PURPOSE: To evaluate the effect of immersion in disinfecting solutions on the color stability of denture base resins and artificial teeth obtained by 3D printing. MATERIALS AND METHODS: Forty discs (15 × 3 mm) were obtained for each group: Lucitone 550 and Cosmos Denture 3D (denture base resins), Duralay and Cosmos TEMP 3D (artificial teeth resins). The discs were immersed in disinfectant solutions: Corega Tabs, 2% chlorhexidine digluconate, 0.25% sodium hypochlorite, and distilled water. Color measurements were obtained with a spectrophotometer before immersion in disinfectants and after the simulated periods of 6 and 12 months. Data (ΔE00 ) were submitted to mixed three-way ANOVA and Bonferroni post-test. RESULTS: For denture base resins, Cosmos Denture 3D showed greater color change regardless of the solution and immersion time. The immersion time of 6 months influenced the color change of the denture base resins regardless of the disinfectant solution. For the artificial teeth resins, the immersion time of 12 months showed a significant color change when compared to 6 months. Cosmos TEMP 3D showed greater color change for all solutions, except for 0.25% sodium hypochlorite. Duralay resin showed greater color change in 2% chlorhexidine, regardless of immersion time. CONCLUSIONS: For denture base resins, the immersion time significantly changed the color regardless of the solution. For artificial teeth resins, Cosmos TEMP 3D showed greater color changes in all solutions when compared to Duralay, except for 0.25% sodium hypochlorite. Chlorhexidine digluconate significantly changed the color of Duralay.


Assuntos
Clorexidina/análogos & derivados , Desinfetantes , Metilmetacrilatos , Dente Artificial , Hipoclorito de Sódio , Bases de Dentadura , Imersão , Teste de Materiais , Impressão Tridimensional , Propriedades de Superfície , Cor
2.
BMC Oral Health ; 23(1): 976, 2023 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-38062423

RESUMO

BACKGROUND: The COVID-19 pandemic led to concerns about the potential airborne transmission of the virus during dental procedures, but evidence of actual transmission in clinical settings was lacking. This study aimed to observe the behavior of dental sprays generated from dental rotary handpieces and to evaluate the effectiveness of high-volume evacuators (HVEs) using laser light sheets and water-sensitive papers. METHODS: A dental manikin and jaw model were mounted in a dental treatment unit. Mock cutting procedures were performed on an artificial tooth on the maxillary left central incisor using an air turbine, a contra-angle electric micromotor (EM), and a 1:5 speed-up contra-angle EM (×5EM). Intraoral vacuum and extraoral vacuum (EOV) were used to verify the effectiveness of the HVEs. The dynamics and dispersal range of the dental sprays were visualized using a laser light sheet. In addition, environmental surface pollution was monitored three-dimensionally using water-sensitive papers. RESULTS: Although the HVEs were effective in both the tests, the use of EOV alone increased vertical dispersal and pollution. CONCLUSIONS: The use of various types of HVEs to reduce the exposure of operators and assistants to dental sprays when using dental rotary cutting instruments is beneficial. The study findings will be helpful in the event of a future pandemic caused by an emerging or re-emerging infectious disease.


Assuntos
Equipamentos Odontológicos de Alta Rotação , Pandemias , Humanos , Dente Artificial , Água
3.
Int J Prosthodont ; 36(6): 769-776, 2023 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-38109398

RESUMO

PURPOSE: To identify the most effective protocol for bonding denture bases and artificial teeth made with different computer-aided design and manufacturing (CAD/CAM) materials (milled and 3D-printed) and conventional heat-polymerized resins. MATERIALS AND METHODS: This review was performed according to the Preferred Reporting Items for Systematic and Meta-Analysis (PRISMA) criteria and registered in the International Prospective Registry of Systematic Reviews PROSPERO (CRD42021276084). An electronic search was performed independently by two examiners in PubMed/MEDLINE, Cochrane Library, Scopus, Web of Science, ProQuest, and OpenGrey databases for articles published up to and including December 2021. RESULTS: The electronic search returned 806 articles, and after duplicates were removed, 589 articles remained. Four articles met the eligibility criteria to be included in this study. After evaluating the different combinations of denture base materials and artificial teeth, it was found that IvoBase CAD Bond (Ivoclar Vivadent) was effective for bonding CAD/CAM denture bases to prefabricated acrylic resin teeth, which showed no differences compared to the heat-polymerized resin denture base bonded to prefabricated acrylic resin teeth (χ2: 68.56; I2: 96%; P < .001). CONCLUSIONS: The IvoBase CAD Bond bonding system can be used for the fabrication of CAD/CAM denture bases with prefabricated acrylic resin teeth.


Assuntos
Colagem Dentária , Dente Artificial , Resinas Acrílicas , Desenho Assistido por Computador , Bases de Dentadura , Teste de Materiais , Propriedades de Superfície
4.
Stomatologiia (Mosk) ; 102(5): 50-55, 2023.
Artigo em Russo | MEDLINE | ID: mdl-37937923

RESUMO

OBJECTIVE: To develop a protocol for setting artificial teeth in a complete removable denture without landmarks on the bite ridges. MATERIAL AND METHODS: Based on the analysis of the literature of various areas of dentistry and the clinical experience of doctors corresponding to each of the disciplines of the specialty, a protocol for setting teeth in a full prosthesis was developed and its theoretical justification was given. RESULTS: Using the method proposed by us, 324 prostheses were made for 162 patients with complete secondary adentia of two jaws. A clinical study and comparison with the generally accepted method of manufacturing prostheses using wax rollers was carried out. The method proposed by us showed greater efficiency based on a comparison of the results of functional tests after prosthetics. CONCLUSION: The described method is part of the concept of manufacturing a functional prosthesis, is used in removable prosthetics, but can also be used in non-removable prosthetics, allows highly accurate, in accordance with individual anatomical parameters and features, to restore the occlusion of the patient during the reconstruction of the dentition, taking into account individual anatomical and functional parameters.


Assuntos
Prótese Total , Prótese Parcial Removível , Humanos , Prótese Parcial , Dente Artificial
5.
J Adhes Dent ; 25(1): 195-210, 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37843502

RESUMO

PURPOSE: Newly developed non-invasive methods for replace a missing tooth and closing single-tooth gaps in the poster- ior region using resin composite are presented. MATERIALS AND METHODS: Four different non-invasive methods and the technical procedures, materials and instruments used are presented in a case series. These include the direct intraoral insertion of composite (with and without individual shaping aids) and indirect restorations, which are fabricated conventionally or digitally and bonded. RESULTS: The case series showed that all four methods can be used to replace single missing teeth in the posterior region, meeting current clinical requirements. Particular attention was paid to the design of the pontics, the dimension of the connector area, firm proximal contacts to the adjacent teeth, hygiene, and appearance of the non-prep bridges (NPBs). The advantages and disadvantages for both the direct and indirect techniques illustrated in this case series were com- pared in detail. CONCLUSIONS: Several direct and indirect non-invasive methods for single-tooth replacement are available today. Although the evidence is still limited, there is a potential for frugal dental interventions with NPBs. Further experimental and clinical studies are necessary to demonstrate that they reliably meet quality requirements (including sufficient survival rates), satisfy the criteria of cost-effectiveness (compared to treatment alternatives) and that there is a demand from the population.


Assuntos
Resinas Compostas , Prótese Parcial , Dente Artificial
6.
Eur J Dent Educ ; 27(2): 306-314, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35411993

RESUMO

INTRODUCTION: Research is lacking in the use of artificial teeth for post-core techniques in undergraduate fixed prosthodontics pre-clinical education. The aim of this study was to compare the reasons for selection and explore the direct student experiences with artificial teeth used in two pre-clinical fixed prosthodontics post-core technique teaching programs conducted in consecutive years. MATERIALS AND METHODS: Fourth year undergraduate dental students who had completed the fixed prosthodontics pre-clinical program were invited to complete an anonymous online surveys. Information was requested on the use and direct student experiences with artificial and natural teeth for post-core techniques. Quantitative data was summarised and qualitative data was clustered into topics. The reasons for selection and use of artificial and natural teeth were compared within and between the two programs. RESULTS: 36% of 70 respondents in 2020 chose to use one or more artificial teeth for the post-core exercises in the pre-clinical program compared with 94% of 77 respondents in 2021 (p < .05). The use was driven by difficulty in sourcing appropriate natural teeth. Respondents reported "ease of use" as the dominant positive user experience with the main negatives being "unrealistic simulation of natural teeth" and "different surface texture/feel when cutting." CONCLUSION: Artificial teeth were reported to provide an appropriate and realistic simulation experience compared with extracted natural teeth and were easier to source. Students focussed on the practicalities of sourcing artificial teeth, associated costs and ease of use ahead of conceivable educational benefits. Cost limited the more widespread use of artificial teeth.


Assuntos
Prostodontia , Dente Artificial , Humanos , Prostodontia/educação , Educação em Odontologia/métodos , Estudantes , Inquéritos e Questionários , Ensino , Currículo
7.
J Prosthet Dent ; 130(6): 811-815, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35131092

RESUMO

A novel design of removable partial dentures (RPDs) is described wherein custom abutments are incorporated into the RPD framework. The artificial teeth and custom abutments are designed by using a computer-aided design (CAD) software program. Subsequently, the RPD framework is designed and merged to the custom abutments in the CAD software program to form a single unit. This modified framework is additively manufactured in metal by using a 3D printer. Thereafter, the framework is adapted to the definitive cast and scanned by using a laboratory scanner. The scanned file is imported into the CAD software program, and the artificial teeth are redesigned. After fabricating each artificial tooth from a polymethylmethacrylate disk and artificial tooth and denture-base assemblies from a wax disk, the RPD is injection molded. This RPD design and fabrication workflow enables a top-down approach by prioritizing the shape and arrangement of the artificial teeth and facilitates their replacement.


Assuntos
Prótese Parcial Removível , Tecnologia Digital , Desenho Assistido por Computador , Software , Dente Artificial , Dente Suporte
8.
J Prosthodont ; 32(S1): 3-10, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35609138

RESUMO

PURPOSE: The aim of this study was to evaluate the bond strength between two types of artificial teeth with a 3D-printed denture base resin using different bonding agents. MATERIALS AND METHODS: Two types of artificial teeth were evaluated: 3D-printed (Cosmos TEMP) and prefabricated polymethylmethacrylate (Biotone) bonded to cylinders (2.5 mm in height and 5 mm in diameter) of 3D-printed denture bases (Cosmos Denture designing by Meshmixer and printed by Flashforge Hunter DLP Resin 3D Printer). Two combinations between denture base and artificial teeth were eveluated: Cosmos Denture - Biotone, n = 30, and Cosmos Denture - Cosmos TEMP, n = 30. For each combination, the specimens were randomly distributed according to the bonding agent: (1) autopolymerized acrylic resin-Duralay, n = 10; (2) 3D-printed resin Cosmos TEMP, n = 10; and (3) methylmethacrylate monomer (MMA) + 3D-printed resin Cosmos TEMP, n = 10, totaling 60 specimens. The application of MMA was done conditioning the tooth surface for 180 seconds; the other agents were applied on the same surface. The virtual design of the 3D-printed resin teeth was obtained by scanning the first maxillary molar of the prefabricated teeth as the same protocol of cylinders. The control group (n = 10) was a conventional heat-polymerized denture base resin (Lucitone 550) bonded to the prefabricated resin teeth (Biotone). The shear bond tests were performed by applying a perpendicular force to the artificial tooth - denture base resin, through a chisel at 1 mm/min until failure. Two-way ANOVA and Bonferroni post hoc tests (α = 0.05) were used for multiple comparisons. RESULTS: For the Biotone tooth, the bond strength was significantly higher using MMA + Cosmos TEMP (10.04 MPa), and similar to the control (11.84 MPa, p = 0.484). For the 3D-printed tooth (Cosmos TEMP), the bond strength using the agents Cosmos TEMP (9.57 MPa) and MMA + Cosmos TEMP (12.72 MPa) were similar to the control (11.84 MPa, p = 0.169 and p = 1, respectively), but different from each other (p = 0.016). CONCLUSIONS: From the results, it is recommended to use: MMA + Cosmos TEMP bonding agent for the Biotone tooth; and Cosmos TEMP or MMA + Cosmos TEMP bonding agents for the Cosmos TEMP tooth, both attached to the 3D-printed denture resin Cosmos Denture.


Assuntos
Colagem Dentária , Bases de Dentadura , Colagem Dentária/métodos , Dente Artificial , Polimetil Metacrilato/química , Metilmetacrilato , Impressão Tridimensional , Teste de Materiais , Propriedades de Superfície , Resistência ao Cisalhamento
10.
J Prosthet Dent ; 129(1): 18-23, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34112523

RESUMO

This article describes a technique for making complete-arch implant-supported fixed prostheses by using intraoral scanning and computer-aided design and computer-aided manufacturing (CAD-CAM) technology for the fabrication of a metal substructure and conventional processing for the prosthesis base. For this, a device was designed to accurately capture the position of multiple implants and the associated digitalized surgical guide, and the metal substructure was planned and milled directly in cobalt-chromium. The color of the gingiva and artificial teeth was selected by using the intraoral scanner software program, and the prosthesis base was processed conventionally. The straightforward methods used to fabricate the prostheses eliminated possible errors associated with conventional substructure casting and occlusal registration.


Assuntos
Implantes Dentários , Planejamento de Prótese Dentária , Planejamento de Prótese Dentária/métodos , Fluxo de Trabalho , Prótese Dentária Fixada por Implante/métodos , Desenho Assistido por Computador , Dente Artificial
11.
Int Dent J ; 73(1): 87-92, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36372591

RESUMO

PURPOSE: This study aimed to assess the 3-body wear of prefabricated and 3D-printed artificial denture teeth. MATERIALS AND METHODS: Four groups of artificial teeth were used; 3D-printed polymethylmethacrylate (PMMA) teeth (PR) and 3 prefabricated commercially available denture teeth: PMMA (Gnathostar, GN), PMMA (SR Orthotyp PE, SR), and Nanohybrid composite (SR Phonares NHC, PH). The 3-body wear test was performed using a steatite ceramic antagonist in a chewing simulator with 750,000 cycles, temperature 23 ± 2 ˚C, and force of 50 N. The abrasive medium was composed of ground millet seeds and white rice mixed with distilled water. The teeth were 3D-scanned before and after the wear test. The 3D images were assessed for teeth wear by measuring the volumetric (3D wear) and the vertical (2D wear) substance loss. The one-way analysis of variance followed by Tukey post hoc test was used to statistically obtain the data analysis. RESULTS: Maximum 3D wear was observed in the PR (51.05 ± 4.53 mm³), followed by GN (20.22 ± 6.29 mm³) and SR (12.12 ± 6.29 mm³) artificial teeth. Minimum wear occurred in the PH teeth (6.24 ± 0.87 mm³). The analytical differences amongst the groups were statistically significant (P < .05) except between PH and SR teeth. For 2D wear measurement, the maximum was seen in the GN teeth (6.29 ± 1.64 mm), followed by PR (5.04 ± 0.83 mm) and then SR (4.53 ± 0.87 mm). The PH teeth (3.09 ± 0.68 mm) again showed minimum wear. Statistically, amongst the groups, the major observable differences (P < .05) were between PH and GN, PH and PR, and SR and GN. CONCLUSIONS: Composite resin teeth had a greater wear resistance than acrylic resin teeth and 3D-printed resin teeth, both of which were comparable. Due to the advancement of digital workflows, manufacturers should devote effort to enhancing 3D-printed teeth.


Assuntos
Polimetil Metacrilato , Dente Artificial , Humanos , Polimetil Metacrilato/química , Resinas Acrílicas/química , Resinas Compostas/química , Impressão Tridimensional , Teste de Materiais , Propriedades de Superfície
12.
Braz. dent. sci ; 26(3): 1-6, 2023. ilus, tab
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1509829

RESUMO

Objective: Teeth play a crucial role in masticatory efficiency and esthetic harmony making rehabilitation of partially edentulous patients a challenge because of the limitations of conventional removable partial dentures. As a therapeutic alternative, thermoplastic polymers are used in current dental practice either for practical processing purposes or aesthetics. However, it is recognized that the bond between acrylic resin artificial teeth and thermoplastic polymers has no chemical interaction, and depends on retentive features added to the teeth. This study analyzed the efficacy of two retentive forms of features through compressive strength test and as a secondary outcome, fracture and displacement resistance test. Material and Methods: Three groups of samples each with 14 sets of acrylic teeth were compared when two retentive features, single hole and groove retention, and a control group with teeth without any specific form. The experimental unit consisted of six maxillary anterior teeth, positioned in a linear pattern into a polypropylene block, where each tooth was submitted to a static load until its removal, on a universal testing machine. Results: Those specimens with a groove retention presented larger resistance to displacement when compared to the other groups (p <0.05). This was emphasized by the fracture of the tooth tested, with part of the cervical portion remaining embed in the base, and not its displacement as with (or without) the retentive feature. Conclusion: In this study, the type of retention influenced significantly to a better retention considering teeth and thermoplastic polymer base. The data in this study indicates that a groove placed on the artificial tooth offers significantly better retention efficacy to the point where the displacement was only possible after its fracture (AU)


Objetivo: Os dentes são um fator essencial na eficiência mastigatória. A harmonia estética e a reabilitação dos indivíduos parcialmente dentados tornam-se um desafio, frente às limitações das próteses parciais removíveis convencionais. Como uma alternativa terapêutica, os polímeros termoplásticos são utilizados na odontologia contemporânea, tanto para o seu processamento prático como seu apelo estético. Entretanto, pouco se sabe a respeito da união entre a resina acrílica de dentes artificiais e resinas termoplásticas, assim como a influência dos mecanismos de retenção, uma vez que não há interação química entre eles. O objetivo deste estudo foi analisar duas formas de retenção de dentes de resina acrílica a bases de prótese de material termoplástico, por força compressiva e como desfecho secundário, teste de resistência a fratura e deslocamento dos dentes artificiais. Material e Métodos: O presente estudo analisou dois tipos diferentes de retenções: uma cavidade com único ponto e uma canaleta de mesial a distal; e como grupo controle, dentes colocados sem qualquer recurso específico. A unidade experimental consistiu de seis dentes superiores anteriores, posicionados em linha em um bloco de polipropileno. Em cada dente artificial foi aplicada força até a sua remoção, em uma máquina universal de ensaios. Resultados: Os resultados mostraram que a retenção com canaleta apresentou maior força de deslocamento, quando comparado com os outros grupos (p <0,05). Tal fato foi evidenciado pelo teste de fratura e deslocamento, no qual parte da porção cervical do dente artificial permaneceu unida à base, não ocorrendo o deslocamento com (ou sem) a retenção. Conclusão: Neste estudo, o tipo de retenção influenciou de forma significante a retenção de dentes artificiais de resina acrílica a bases de prótese termoplásticas. Os dados deste estudo indicam que a confecção da retenção em canaleta nos dentes artificiais oferece significante aumento na eficiência da retenção, ao ponto em que o deslocamento do dente ocorreu somente após sua fratura (AU).


Assuntos
Polipropilenos , Dente Artificial , Resinas Acrílicas , Dentaduras
13.
Rev. odontol. UNESP (Online) ; 52: e20220035, 2023. tab, ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1515463

RESUMO

Introduction: The coronal opening is essential, during endodontic treatment, for direct access to the root canals. Usually, in the anterior teeth, endodontic access is achieved on the palatal/lingual surface, more specifically in the cingulum region. However, the lack of observation for dental positioning can lead to some accidents and complications, such as buccal perforations, causing esthetic damage and compromising the treatment. Objective: To evaluate the applicability of a new approach for performing coronal opening in anterior teeth, regarding the wear caused on the tooth crown, and to evaluate the ease of performing the new technique to minimize the risk of perforation. Material and method: Ten students (n=10) from the Improvement in Endodontics program participated in the present study. Twenty artificial teeth were used, which were upper, central incisors. Each participant performed two coronal openings. First, with no guidance (Group A - Conventional Technique) and afterward, a new opening, but with guidance with the spherical diamond tip placed parallel to the long axis of the tooth (Group B - Modified Technique). Result: The results showed that 90% of the participants considered the Modified Technique as having lower risk of accidents, as well as being easier for locating the pulp chamber. There was a statistical difference both in the measurement of the total area of wear and in the width, while there was no statistical difference in the height. Conclusion: Preliminary data collected with the survey were satisfactory for the Modified Technique. Statistically, it showed a favorable difference in relation to the area of wear and the width. However, in height there was no statistical difference.


Introdução: A abertura coronária é fundamental durante o tratamento endodôntico para um acesso direto aos canais radiculares. Em geral, em dentes anteriores, o acesso endodôntico é realizado na face palatina/lingual, mais especificamente em região de cíngulo. Entretanto, a falta de observação do posicionamento dentário pode levar a alguns acidentes e complicações, como as perfurações por vestibular, ocasionando dano estético e comprometendo o tratamento. Objetivo: Avaliar a aplicabilidade de uma nova abordagem de realização da abertura coronária em dentes anteriores, quanto ao desgaste ocasionado na coroa dentária, e avaliar a facilidade de execução da nova técnica para minimizar os riscos de perfurações. Material e método: Dez alunos (n=10) do curso de Aperfeiçoamento em Endodontia participaram do estudo. Foram utilizados vinte dentes artificiais, sendo eles incisivos centrais superiores. Cada participante realizou duas aberturas coronárias. Primeiramente sem nenhuma orientação (Grupo A - Técnica Convencional) e após, uma nova abertura, porém com orientação, com a ponta diamantada esférica posicionada paralelamente ao longo eixo do dente (Grupo B - Técnica Modificada). Resultado: Os resultados demonstraram que 90% dos participantes consideraram a Técnica Modificada como a de menor risco de acidentes e, ainda, de mais fácil localização da câmara pulpar. Houve diferença estatística tanto para a medida da área total de desgaste quanto para a largura, enquanto na altura não houve diferença estatística. Conclusão: Os dados preliminares coletados pelo questionário se mostraram satisfatórios para a Técnica Modificada. Estatisticamente, apresentou diferença favorável em relação à área de desgaste e largura, já em altura não houve diferença estatística.


Assuntos
Dente Artificial , Inquéritos e Questionários , Coroa do Dente , Cavidade Pulpar , Endodontia , Incisivo , Interpretação Estatística de Dados
14.
Am J Dent ; 35(6): 284-290, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36508183

RESUMO

PURPOSE: To evaluate and compare in vitro and in vivo color parameters of hybrid ceramic, resin nanoceramic, and artificial acrylic resin teeth. METHODS: For the in vitro stages, 120 specimens (2 mm) were prepared from Vita Enamic (VE), Lava Ultimate (LU), CeraSmart (CS), and acrylic teeth (IV), and immersed in coffee, red wine, and distilled water for 24, 72, and 144 hours. For the in vivo stage, 16 individuals received a complete denture that had upper premolars made of VE, LU, CS blocks, and IV. The color was measured at 1, 3, and 6 months. Color difference (ΔE00), translucency (TP), and contrast ratio (CR) were obtained using a spectrophotometer. Shapiro Wilk, one-way ANOVA, and repeated measures ANOVA were used for statistical analysis. RESULTS: ΔE00 of VE and LU were higher than CS and IV (P< 0.05). ΔTP of VE and LU were lower than CS and IV (P< 0.05). ΔTP of CS was higher in red wine compared to coffee. ΔCR of CS and IV were increased with prolonged immersion (P< 0.001). ΔE00 and ΔCR were similarly affected in coffee and red wine. All discolorations were higher than clinical acceptability (ΔE00> 1.77). For in vivo stages, ΔE00 of VE and LU increased over time (P< 0.01). No difference was detected between in vivo and in vitro ΔE00 of CS (P> 0.05). ΔE00 of VE, LU, and IV was higher in in vitro stages. LU and VE showed lower color stability; their use in esthetic regions is questionable. The prolonged immersion increased discoloration. Coffee and red wine had a similar effect on discoloration and opalescence. Discoloration in laboratory conditions did not correspond to the clinical discoloration according to the new method presented in this study. CLINICAL SIGNIFICANCE: The use of CAD-CAM blocks for endocrowns is rising; however, Lava Ultimate and Vita Enamic showed lower color stability, thus, their use in esthetic regions is questionable. This is the first study that investigates the discoloration of CAD-CAM blocks in clinical use. Discoloration in laboratory conditions did not correspond to the clinical discoloration.


Assuntos
Cerâmica , Desenho Assistido por Computador , Humanos , Teste de Materiais , Propriedades de Superfície , Cor , Dente Artificial
15.
Dent Mater ; 38(12): 1956-1962, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36424204

RESUMO

OBJECTIVES: To characterize a resin-based polymer used for 3D printing (3D) provisional restorations and artificial teeth by evaluating relevant material's properties (flexural strength (σf), elastic modulus (E), water sorption (Wsp) and solubility (Wsl)) and biocompatibility, and comparing to a bis-acryl composite resin (BA) and a heat-cured acrylic resin (AR). METHODS: Structures were fabricated from 3D, BA and AR. Bar-shaped specimens (n = 30) were submitted to three-point flexure (in 37ºC water and constant displacement rate: 1 ± 0.3 mm/min) until fracture to calculate σf and E. Additional specimens (n = 30) were aged in 37ºC distilled water for six months before testing for σf. Disc-shaped specimens (n = 5) were dried in desiccators and oven until weight stability was reached, then they were immersed in distilled water for seven days, weighed and submitted to the drying process to obtain Wsp and Wsl. SRB and MTT assays were used to evaluate biocompatibility. Data were statistically analyzed using Kruskal Wallis, Student-Newman-Keuls (α = .05), and Weibull distribution. ANOVA and Tukey (α = .05) were used to evaluate the biocompatibility data. RESULTS: 3D structures showed higher σf than AR after aging. The BA showed the lowest values for σf and E, at baseline and after aging. All materials showed Wsp and Wsl values within the recommended standard values. AR structures showed lower cell viability (71.9%) than 3D (92.9%) and BA (90.8%) when using the SRB test. No difference was found when using MTT (p > .05). SIGNIFICANCE: The evaluated polymer-based 3D printing material showed adequate biomechanical behavior for using as a provisional restoration and artificial teeth.


Assuntos
Polímeros , Dente Artificial , Humanos , Idoso , Impressão Tridimensional , Resinas Acrílicas , Água
16.
Clin Oral Investig ; 26(12): 7149-7155, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35982349

RESUMO

OBJECTIVES: To investigate whether artificial CAD/CAM processed (computer-aided design/manufacturing) teeth could be a feasible option for the production of dental in vitro models for biomechanical testing. MATERIAL AND METHODS: Disks (n = 10 per group) made from two different CAD/CAM-materials, one fiber-reinforced composite (FRC; Trinia, Bicon) and one polymethylmethacrylate-based resin (PMMA; Telio CAD, Ivoclar Vivadent), as well as bovine teeth (n = 10), were tested for their shear bond strength (SBS) and scored according to the adhesive remnant index (ARI). In addition, CAD/CAM-manufactured lower incisor teeth were tested for their ultimate load (Fu). RESULTS: With regard to SBS, both PMMA (17.4 ± 2.2 MPa) and FRC (18.0 ± 2.4 MPa) disks showed no significant difference (p = 0.968) compared to bovine disks (18.0 ± 5.4 MPa). However, the samples differed with regard to their failure mode (PMMA: ARI 4, delamination failure; FRC: ARI 0 and bovine: ARI 1.6, both adhesive failure). With regard to Fu, FRC-based teeth could withstand significantly higher loads (708 ± 126 N) than PMMA-based teeth (345 ± 109 N) (p < 0.01). CONCLUSION: Unlike PMMA-based teeth, teeth made from FRC showed sufficiently high fracture resistance and comparable SBS. Thus, FRC teeth could be a promising alternative for the production of dental in vitro models for orthodontic testing. CLINICAL RELEVANCE: CAD/CAM-processed teeth made from FRC enable the use of standardized geometry and constant material properties. Using FRC teeth in dental in vitro studies has therefore the potential to identify differences between various treatment options with rather small sample sizes, while remaining close to the clinical situation.


Assuntos
Colagem Dentária , Dente Artificial , Bovinos , Animais , Polimetil Metacrilato/química , Teste de Materiais , Resinas Compostas/química , Desenho Assistido por Computador , Resistência ao Cisalhamento , Propriedades de Superfície , Análise do Estresse Dentário
17.
Stomatologiia (Mosk) ; 101(3): 61-69, 2022.
Artigo em Russo | MEDLINE | ID: mdl-35640181

RESUMO

THE AIM THE STUDY: The purpose of the work is to perform automated alignment of two-dimensional archival photographs of the first prosthesis and a digital model of the complete removable prosthesis by superposition in order to determine or deny their possible belonging to one user. MATERIALS END METHODS: The superposition was carried out in the Exocad program (DentalCAD 3.0 Galway) using the standard 2D-3D alignment algorithm of the «SmileDesign¼ module; in the same program. In addition, Keynote and Fusion 360, and Autodesk programs were used. Statistical measurements were carried out at the statistically significant level of p<0.05. RESULTS: A comparison of four different-angle and different-scale photographic images of a removable denture of the upper jaw teeth with a three-dimensional copy of the same version of the prosthesis of the life physician of the royal family E.S. Botkin was made. When superimposing a digital three-dimensional model and a two-dimensional photograph of the original prosthesis with marked anthropometric points (n=51), 21 of them coincided or touched each other (41.2%). Another 26 points were located side by side (distance up to 1.5 mm) (50.9%) and 4 did not coincide (distance >1.5 mm, but no more than 3.5-4 mm) (7.8%). When the reference points were combined, the contours, the configuration of the relief and the peripheral boundaries of all three objects mostly coincided. The linear longitudinal and transverse dimensions of the bases of the prostheses also mostly coincided. The exception was the distal border of the bases, and the level of the cutting edges of the anterior artificial teeth, where complete coincidence was not observed, due to differences in the degree of erasability. CONCLUSION: Comparison of the original prosthesis from Ipatiev's house and its stereolithographic model was a test for the accuracy of the matching method used. The stereotype of the compared images is proved and the consistency of the possibility of computer combination of three-dimensional and two-dimensional objects is confirmed. The use of traditional methods of forensic identification and evaluation of the results by methods of mathematical statistics allowed us to conclude that the two different complete removable dentures of the upper jaw depicted in the photographs belong to one user.


Assuntos
Prótese Total , Odontologia Legal , Prótese Parcial , Humanos , Dente Artificial
18.
Dent Med Probl ; 59(2): 249-253, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35584297

RESUMO

BACKGROUND: Correct color assessment and the selection of the color of the prosthetic restoration are important aspects of prosthetic treatment, which significantly affect the success of the treatment. OBJECTIVES: The aim of this study was to compare 2 commercial devices used for tooth color selection. MATERIAL AND METHODS: The color of maxillary right central incisors and right canines was assessed in a group 100 patients aged 22-40 years (25.11 ±3.24 years), using the Easyshade® spectrophotometer and the ShadeStar® colorimeter. Two visual shade guides were used as references for the tests - VITA VITAPAN® Classical and VITA 3D­Master. The 2 instruments and the 2 visual shade guides were assessed in terms of agreement in tooth color selection. RESULTS: There were statistically significant differences between the 2 instruments in terms of agreement in tooth color selection as well as between the 2 shade guides. The VITA VITAPAN Classical shade guide was shown to be more accurate in tooth color selection than VITA 3D­Master. There was agreement between the Easyshade spectrophotometer and ShadeStar colorimeter measurements for incisors in 49% of cases with the VITA VITAPAN Classical shade guide and in 22% of cases with VITA 3D­Master. In the comparative analysis of the Easyshade and ShadeStar devices with regard to the measurements performed on canines there was 52% agreement for the VITA VITAPAN Classical shade guide and 32% agreement for VITA 3D­Master. CONCLUSIONS: The VITA VITAPAN Classical system demonstrated superior agreement in shade selection as compared to the VITA 3D­Master system. A low degree of agreement between the optical devices used in the selection of the color of artificial teeth may indicate optical differences between devices from different manufacturers.


Assuntos
Dispositivos Ópticos , Pigmentação em Prótese , Cor , Percepção de Cores , Incisivo , Dente Artificial
19.
Dent Mater J ; 41(4): 573-579, 2022 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-35418549

RESUMO

This study aimed to evaluate the effect of retention hole designs in artificial teeth on failure resistance of the connection with a thermoplastic denture base resin. Artificial teeth with the following retention hole designs were attached to polyester and polyamide resins: no hole, vertical hole, horizontal hole, and vertical and horizontal holes. An artificial tooth with no hole attached to polymethyl methacrylate was prepared as the control. The load was applied until connection failure occurred between the artificial tooth and resin, and failure resistance was detected. Although the control showed the highest resistance, the artificial tooth with vertical and horizontal holes showed higher resistance than those with other retention hole designs in both thermoplastic resins. Providing vertical and horizontal retention holes in artificial teeth may be effective in improving failure resistance of the connection with thermoplastic resins.


Assuntos
Resinas Acrílicas , Dente Artificial , Bases de Dentadura , Teste de Materiais , Nylons , Polimetil Metacrilato
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