Papers by Alfredo Mesquita
Dental Materials, Jul 1, 2023
ImplantNews, 2006
página 1 de 1, 1 / 1, LILACS, seleciona. para imprimir. Fotocópia. experimental, Documentos relac... more página 1 de 1, 1 / 1, LILACS, seleciona. para imprimir. Fotocópia. experimental, Documentos relacionados. Id: 461727. Autor: Mesquita, Alfredto Mikail Melo; Souza, Rodrigo Othávio de Assunção e; Vasconcelos, Diego Klee de; RAvelar, ander Pereira; Bottino, Marco Antônio. ...
Journal of Functional Biomaterials, Feb 26, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
A manutencao das restauracoes implantossuportadas depende do equilibrio e da manutencao da homeos... more A manutencao das restauracoes implantossuportadas depende do equilibrio e da manutencao da homeostasia dos tecidos peri-implantares, sendo assim, dependente de uma oclusao ajustada a cada situacao. Conceitos oclusais, assim como relacionados a restauracoes unitarias, serao discutidos e apresentados por meio de casos clinicos.(AU)
Rev. paul. …, 1991
Base de dados : LILACS. Pesquisa : 94832 [Identificador único]. Referências encontradas : 1 [refi... more Base de dados : LILACS. Pesquisa : 94832 [Identificador único]. Referências encontradas : 1 [refinar]. Mostrando: 1 .. 1 no formato [Detalhado]. página 1 de 1, 1 / 1, LILACS, seleciona. para imprimir. Fotocópia. Vieira, José Gilberto H. experimental, Documentos relacionados. Id: ...
PubMed, Jun 1, 2016
The first choice for anterior rehabilitation has been metal-free materials due to their successfu... more The first choice for anterior rehabilitation has been metal-free materials due to their successful aesthetic results. However, the definitive clinical work accuracy may be affected by the lack of clinicians' expertise and familiarization with the latest techniques, as well as recurrent laboratory procedures. This manuscript presents a clinical experience with zirconia ceramic for anterior crowns and zirconia CAD/CAM abutments, including both clinical and laboratory steps after the implant installation. The 'emergence profile' and the 'double scanning' techniques obtained by the waxing technique appear to be a very promising procedure for aesthetic improvement of the single-implant zirconia restoration in anterior teeth.
Journal of Dental Education, Jul 30, 2020
Context: Students can have some issues in the comprehension and execution of coronal preparations... more Context: Students can have some issues in the comprehension and execution of coronal preparations in fixed partial prosthesis (FPP). Some issues pertain to the amount of reduction, the inclination, and the positioning, all of which are important for the execution of an ideal preparation while respecting the required biomechanical principles. Objective: The present study's aim was to evaluate the main problems experienced by graduation students regarding coronal preparation in FPP and to suggest teaching skills to help students and professors.
Scientific Reports, Oct 12, 2022
This study evaluated the bacterial infiltration and the detorque of indexed and non-indexed abutm... more This study evaluated the bacterial infiltration and the detorque of indexed and non-indexed abutments of Morse taper implants (MTI) after mechanical cycling (MC). 40 MTI were distributed into four groups: IIA (indexed implant abutments); NIIA (non-indexed implant abutments); IIAMC (indexed implant abutments submitted to MC); NIIAMC (non-indexed implant abutments submitted to MC), which were carried out under one million 5 Hz frequency and 3 Bar pressure. After mechanical cycling, all groups were immersed in a bacterial solution in Brain Heart Infusion Agar. After detorque, the bacteria infiltration was evaluated by counting the colony-forming units. For the bacterial infiltration, analysis was applied to the Kruskal-Wallis test (p = 0.0176) followed by Dunn's test. For the detorque analysis, the two-way repeated-measures ANOVA was applied, followed by the Tukey's test (p < 0.0001). Bacteria infiltration was highly observed in NIIA (p = 0.0027) and were absent in IIAMC and NIIAMC. The detorque values for IIA (19.96Ncm ± 0.19Ncm), NIIA (19.90Ncm ± 0.83Ncm), and NIIAMC (19.51Ncm ± 0,69Ncm) were similar and remained close to the initial value, while IIAMC (55.2Ncm ± 2.36Ncm) showed an extremely significant torque value increase (p < 0.0001). The mechanical cycling resulted in mechanical sealing of the implant-abutment interface, preventing bacterial infiltration in the indexed and non-indexed specimens, and increasing the detorque strength in the group of indexed abutments. Oral rehabilitation with dental implants requires more than just osseointegration success. The peri-implant tissues should also be in harmony with the existing dentition to achieve better functional and aesthetic rehabilitation 1. Regardless of the prosthetic platform, the implant-abutment interface is located below the gingival margin, where microbial infiltrations might occur, which can lead to bone loss through the inflammatory process, thus compromising not only the peri-implant tissues but also the osseointegration process 1-4. The long-term aesthetic and functional success of a prosthetic restoration supported by osseointegrated implants are causally related to the precision of the implant abutments adjustment 5. The preload applied on the abutment screw is a key mechanical factor to be taken into account, as it directly interferes with the stability of these components, creating a compressive tension of the screw/prosthetic abutment, abutment/implant, and prosthetic abutment/implant thread interfaces. The applied torque magnitude is causally related to the applied preload force and is limited by the screw resistance and by bone-implant interface resistance 6. The internal conical connection, designed for the Morse taper implant, shows a cone shape at the implantabutment interface, where there is great mechanical retention between the connectors, being characterized by high contact pressure and resistance to friction between the internal implant surface and abutment, aiming to
Odonto, Jun 30, 2007
RESUMO O objetivo deste trabalho foi avaliar a resistência à tração entre resinas de uso direto d... more RESUMO O objetivo deste trabalho foi avaliar a resistência à tração entre resinas de uso direto de três diferentes marcas comerciais, simulando reparos, utilizando ou não adesivo nesta interface. Para tanto foram confeccionadas 60 bases cônicas em resina composta (TPH) apresentando as seguintes dimensões: 5mm de comprimento, com uma base maior de 5mm e uma base menor de 3mm de diâmetro. Essas bases foram divididas aleatoriamente em 6 grupos. Sob estas bases foram aplicadas, com auxílio de uma matriz bi-partida de teflon, três resinas: TPH (Dentsply), InTen-S (Ivoclar), Filtek Supreme (3M-ESPE), com ou sem a utilização de um adesivo dentinário (Single Bond-3M-ESPE), de maneira a obter amostras na forma de ampulheta. Após armazenamento destas amostras durante 7 dias à 37° C, estas foram submetidas ao ensaio de tração em uma máquina de ensaios universal com velocidade de 1,0 mm/ min e célula de carga de 500Kgf a qual carregou a amostra até que ocorresse sua fratura. Os dados obtidos (MPa) foram submetidos à Análise de Variância (ANOVA), e ao o teste de Tukey (5%). As médias e desvios padrão foram obtidos dos grupos sem e com adesivo, respectivamente: G1-TPH
PubMed, Sep 16, 2010
Aim: This study compared the bond strength durability of a feldspathic veneering ceramic to glass... more Aim: This study compared the bond strength durability of a feldspathic veneering ceramic to glass-infiltrated reinforced ceramics in dry and aged conditions. Methods: Disc shaped (thickness: 4 mm, diameter: 4 mm) of glass-infiltrated alumina (In-Ceram Alumina) and glass-infiltrated alumina reinforced by zirconia (In-Ceram Zirconia) core ceramic specimens (N=48, N=12 per groups) were constructed according to the manufacturers' recommendations. Veneering ceramic (VITA VM7) was fired onto the core ceramics using a mold. The core-veneering ceramic assemblies were randomly divided into two conditions and tested either immediately after specimen preparation (Dry) or following 30000 thermocycling (5-55 ºC±1; dwell time: 30 seconds). Shear bond strength test was performed in a universal testing machine (cross-head speed: 1 mm/min). Failure modes were analyzed using optical microscope (x20). The bond strength data (MPa) were analyzed using ANOVA (α=0.05). Results: Thermocycling did not decrease the bond strength results for both In-Ceram Alumina (30.6±8.2 MPa; P=0.2053) and In-Ceram zirconia (32.6±9 MPa; P=0.3987) core ceramic-feldspathic veneering ceramic combinations when compared to non-aged conditions (28.1±6.4 MPa, 29.7±7.3 MPa, respectively). There were also no significant differences between adhesion of the veneering ceramic to either In-Ceram Alumina or In-Ceram Zirconia ceramics (P=0.3289). Failure types were predominantly a mixture of adhesive failure between the veneering and the core ceramic together with cohesive fracture of the veneering ceramic. Conclusion: Long-term thermocycling aging conditions did not impair the adhesion of the veneering ceramic to the glass-infiltrated alumina core ceramics tested.
Journal of Prosthodontics, Oct 5, 2015
PURPOSE In testing adhesion using shear bond test, a combination of shear and tensile forces occu... more PURPOSE In testing adhesion using shear bond test, a combination of shear and tensile forces occur at the interface, resulting in complex stresses. The jig designs used for this kind of test show variations in published studies, complicating direct comparison between studies. This study evaluated the effect of different jig designs on metal-ceramic bond strength and assessed the stress distribution at the interface using finite element analysis (FEA). MATERIALS AND METHODS Metal-ceramic (Metal: Ni-Cr, Wiron 99, Bego; Ceramic: Vita Omega 900, Vita) specimens (N = 36) (diameter: 4 mm, veneer thickness: 4 mm; base diameter: 5 mm, thickness: 1 mm) were fabricated and randomly divided into three groups (n = 12 per group) to be tested using one of the following jig designs: (a) chisel (CH) (ISO 11405), (b) steel strip (SS), (c) piston (PI). Metal-ceramic interfaces were loaded under shear until debonding in a universal testing machine (0.5 mm/min). Failure types were evaluated using scanning electron microscopy (SEM). FEA was used to study the stress distribution using different jigs. Metal-ceramic bond strength data (MPa) were analyzed using ANOVA and Tukey's tests (= 0.05). RESULTS The jig type significantly affected the bond results (p = 0.0001). PI type of jig presented the highest results (MPa) (p < 0.05) (58.2 ± 14.8), followed by CH (38.7 ± 7.6) and SS jig type (23.3 ± 4.2) (p < 0.05). Failure types were exclusively a combination of cohesive failure in the opaque ceramic and adhesive interface failure. FEA analysis indicated that the SS jig presented slightly more stress formation than with the CH jig. The PI jig presented small stress concentration with more homogeneous force distribution compared to the CH jig where the stress concentrated in the area where the force was applied. CONCLUSION Metal-ceramic bond strength was affected by the jig design. Accordingly, the results of in vitro studies on metal-ceramic adhesion should be evaluated with caution. CLINICAL SIGNIFICANCE When adhesion of ceramic materials to metals is evaluated in in vitro studies, it should be noted that the loading jig type affects the results. Clinical observations should report on the location and type of ceramic fractures in metal-ceramic reconstructions so that the most relevant test method can be identified.
Clinical, Cosmetic and Investigational Dentistry, Dec 1, 2019
Purpose To evaluate the survival rate in restored teeth with three different types of retainers p... more Purpose To evaluate the survival rate in restored teeth with three different types of retainers prior to the fixing of crowns with zirconia through this retrospective clinical study. It is unclear how the type of post and core rehabilitation, and type of resin cement affect the longevity of teeth restored with crowns. Methods In a private clinic, a total of 101 retainers installed by the same professional between June 2008 and January 2018, with an average time of 58.2 months (4.8 years), were analyzed regarding the following factors: survival, cement and failure type. Three types of retainers were used according to the indications found in the literature: filling with Z250 light-cured composite resin, 22 elements; fiberglass post with Z250 light-cured composite resin, 45 elements; and cast metallic core in silver-tin alloy, 34 elements. The retainers were cemented with chemically cured cement, U100, U200, or Panavia F. Results Data were subjected to Kaplan-Meier analysis (p=0.495). Although the study presented several limitations, no significant differences were observed in the success rates between the types of intra-radicular retainers and the type of cement. The success rates were as follows: metal core, 97.1%; fiberglass post, 95.6%; and filling, 100%. On average, failures occurred at 48.4 months. Conclusion In view of the results, it is possible to conclude that the different retainers evaluated have similar survival rates.
Journal of Prosthetic Dentistry, Oct 1, 2014
STATEMENT OF PROBLEM An imprecise fit between frameworks and supporting dental implants in loaded... more STATEMENT OF PROBLEM An imprecise fit between frameworks and supporting dental implants in loaded protocols increases the strain transferred to the periimplant bone, which may impair healing or generate microgaps. PURPOSE The purpose of this study was to investigate the microstrain between premachined 1-piece screw-retained frameworks (group STF) and screw-retained frameworks fabricated by cementing titanium cylinders to the prefabricated framework (group CTF). This procedure was developed to correct the misfit between frameworks and loaded implants. MATERIAL AND METHODS Four internal hexagon cylindrical implants were placed 10 mm apart in a polyurethane block by using the surgical guides of the corresponding implant system. Previously fabricated titanium frameworks (n=10) were divided into 2 groups. In group STF, prefabricated machined frameworks were used (n=5), and, in group CTF, the frameworks were fabricated by using a passive fit procedure, which was developed to correct the misfit between the cast titanium frameworks and supporting dental implants (n=5). Both groups were screw-retained under torque control (10 Ncm). Six strain gauges were placed on the upper surface of the polyurethane block, and 3 strain measurements were recorded for each framework. Data were analyzed with the Student t test (=.05). RESULTS The mean microstrain values between the framework and the implants were significantly higher for group STF (2517 m) than for group CTF (844 m) (P<.05). CONCLUSIONS Complete-arch implant frameworks designed for load application and fabricated by using the passive fit procedure decreased the strain between the frameworks and implants more than 1 piece prefabricated machined frameworks.
Medicina-lithuania, Jan 14, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Journal of Prosthodontics, Dec 17, 2020
Conventional techniques described in the literature for the manufacture of ocular prostheses are ... more Conventional techniques described in the literature for the manufacture of ocular prostheses are time-consuming since they involve manual work. The use of technologies could improve this laborious process, providing better aesthetic outcomes. This technique describes how to manufacture the ocular portion of an orbital prosthesis using a smartphone camera, color calibration with a tooth shade guide, and digital printing. This method allows obtaining customized ocular prosthesis by using a photograph of the patient's eye, thus eliminating the need for hand-painting and manual work, reducing fabrication time.
A utilizacao do CAD/CAM para o tratamento de edentulismo unitario e multiplo na regiao anterior t... more A utilizacao do CAD/CAM para o tratamento de edentulismo unitario e multiplo na regiao anterior tem aumentado consideravelmente devido a aplicacao de materiais cerâmicos esteticos e personalizacao dos pilares proteticos, melhorando o perfil de emergencia e a estetica branca final. Nesse contexto, serao abordados os conceitos e as definicoes para o emprego dessa tecnologia, assim como sua aplicabilidade na clinica diaria. (AU)
The Open Dentistry Journal, Dec 23, 2020
Introduction: The Acquired Immune Deficiency Syndrome (AIDS) is a condition that manifests itself... more Introduction: The Acquired Immune Deficiency Syndrome (AIDS) is a condition that manifests itself after the infection of the human organism by the Human Immunodeficiency Virus (HIV). In 1996, the Highly Active Antiretroviral Therapy (HAART) was introduced, with the aim of slowing down the immunodeficiency and restoring the immunity of these patients, extending their life expectancy. Consequently, the need for rehabilitating dental treatments arose, aiming to improve oral health, self-esteem and the quality of life of these patients. This current study was designed to assess vertical dimensional changes in the peri-implant bone level around the placement of dental implants in AIDS patients using HAART.
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Papers by Alfredo Mesquita