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The rehabilitation of patients with dental implant-supported restorations is an ideal treatment option in contemporary dentistry. The aim of this review was to compile and to demonstrate the mechanical response during loading condition, on the stress distributions of implant-supported prostheses. The findings show that the majority of stresses were concentrated in the cervical region of the implant/abutment interface and that they can be affected by several clinical parameters and loading conditions. Finally, the final prosthetic design should combine superior mechanical response, long-term survival rate and allow patient satisfaction.

Submitted by Dario Adolfi (spaziolabcadcam@gmail.com) on 2021-01-13T14:41:02Z No. of bitstreams: 1 tese doutorado Dario Adolfi .pdf: 3321413 bytes, checksum: 9db36e53549ab4207f5e1eb17d94fecc (MD5) Approved for entry into archive by Silvana Alvarez null (silvana@ict.unesp.br) on 2021-01-13T17:45:44Z (GMT) No. of bitstreams: 1 adolfi_d_dr_sjc.pdf: 3321413 bytes, checksum: 9db36e53549ab4207f5e1eb17d94fecc (MD5) Made available in DSpace on 2021-01-13T17:45:44Z (GMT). No. of bitstreams: 1 adolfi_d_dr_sjc.pdf: 3321413 bytes, checksum: 9db36e53549ab4207f5e1eb17d94fecc (MD5) Previous issue date: 2020-10-09 Este estudo avaliou a eficiência da pré-carga antes e após fadiga, desajuste vertical, carga para fratura e a concentração de tensões em restaurações de zircônia cimentadas ou acopladas a uma base de titânio (TB). Para isto, quarenta implantes foram incluídos em cilindros de polióxido de metileno (POM-Delrin-Dupont) e separados em dois grupos: restauração de zircônia cimentada em um TB ou acoplada em um TB experimental. Os corpos de prova tiveram o torque e o desajuste vertical avaliados antes e após a fadiga cíclica (200 N / 2 Hz / 2 x 106 ciclos / 37 °C). A carga até a fratura foi calculada em uma máquina universal de ensaios (1 mm / min, 1000 kgf) e as falhas foram avaliadas por estereomicroscopia e microscopia eletrônica de varredura. Modelos tridimensionais foram criados baseados na geometria dos espécimes laboratoriais e a concentração de tensão calculada pelo método dos elementos finitos. Os dados dos testes in vitro foram submetidos à análise de variância dois fatores e teste de Tukey (α = 0,5). As restaurações cimentadas apresentaram menor perda de torque (19,79 N.cm), menor desajuste vertical (3,77 μm), menor concentração de tensão na restauração (88,2 MPa) e maior carga de fratura (451,3 N) do que as restaurações acopladas (15,95 N.cm, 10,51 μm, 99,8 MPa e 390,8 N, respectivamente). Conclusão: A presença de uma camada de cimento entre a restauração e a base de titânio reduziu a suscetibilidade ao afrouxamento do parafuso do pilar, melhorou a resistência à carga compressiva e reduziu a concentração de tensão na restauração. The goal of this study was to evaluate the torque and vertical misfit before and after fatigue, the load to failure and the stress concentration of zirconia restorations cemented or notched to a titanium base (TB). Forty implants were included in Acetal Polyoxymethylene (POM-Delrin-Dupont) cylinders and divided in two groups: zirconia restoration cemented on a TB and zirconia restoration notched on an experimental TB. The specimens had their torque loosening and vertical misfit evaluated before and after cyclic fatigue (200 N / 2 Hz/ 2 x 106 cycles /37 °C). Load to failure was calculated in an universal testing machine (1 mm/min, 1000 kgf) and failures were evaluated by optical microscopy and scanning electron microscopy. Three-dimensional models were created based in the in vitro geometries and the stress concentration calculated using the finite element method. Data from the in vitro tests were submitted to two-way analysis of variance and Tukey test (α = 0.5). The cemented restorations presented less torque loosening (19.79 N.cm), lower vertical misfit (3.77 μm), lower stress concentration in the restoration (88.2 MPa) and higher fracture load (451.3 N) than notched restorations (15.95 N.cm, 10.51 μm, 99.8 MPa and 390.8 N, respectively). Conclusion: The presence of a cement layer between restoration and titanium base reduced the susceptibility to abutment screw loosening, improved the resistance to compressive load and reduced the stress concentration in the restoration.

Dario Adolfi,1 João Paulo Mendes Tribst,1 Maurício Adolfi,2 Amanda Maria de Oliveira Dal Piva,1 Guilherme de Siqueira Ferreira Anzaloni Saavedra,1 Marco Antonio Bottino1 1Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), Institute of Science and Technology, São José dos Campos, São Paulo, Brazil; 2Private Practice, São Paulo, BrazilCorrespondence: João Paulo Mendes Tribst Eng. Francisco José Longo, nº 777. Jardim São Dimas, São José dos Campos 12245-000, SP, BrazilTel +55 12 3947 9032Fax +55 12 3947 9010Email joao.tribst@gmail.comAbstract: The hybrid abutment emerged as an alternative to maintain a stable and favorable volume of peri-implant tissue; it is composed of a mesostructure in ceramic and a metallic connection, which can be machined according to the peri-implant emergence profile. This case report presented the clinical steps for a dental implant with immediate provisional restoration, followed by the installation of implant-supported all-ceramic crowns with zirconia abutment and platform switching. A 40-year-old male patient was rehabilitated with an implant-supported ceramic crown in the region of element 11 and a ceramic veneer was cemented on the upper right central incisor. To do so, an atraumatic extraction of the upper left central incisor was performed followed by implant placement and immediate loading. In this case, a zirconia hybrid abutment was used with a metallic link in the cervical region with a concave platform switching base. This association of clinical steps enabled improving the aesthetics in the anterior dental region.Keywords: dental implants, soft tissue, esthetic, adhesive