Comparison of the marginal fit of different all-ceramic and metal-ceramic crown systems: an in vitro study

2010 ◽  
Vol 3 (2) ◽  
pp. 106-110 ◽  
Author(s):  
R. Polansky ◽  
A. Heschl ◽  
G. Arnetzl ◽  
M. Haas ◽  
W. Wegscheider

2019 ◽  
Vol 28 (9) ◽  
pp. 1037-1043 ◽  
Author(s):  
Ibrahim Salim Duqum ◽  
Christian Brenes ◽  
Gustavo Mendonca ◽  
Thiago Almedia Prado Naves Carneiro ◽  
Lyndon F. Cooper


2014 ◽  
Vol 39 (3) ◽  
pp. 308-316 ◽  
Author(s):  
P Tidehag ◽  
K Ottosson ◽  
G Sjögren

SUMMARY The present in vitro study concerns determination of the pre-cementation gap width of all-ceramic crowns made using an in-office digital-impression technique and subsequent computer-aided design/computer-aided manufacturing (CAD/CAM) production. Two chairside video camera systems were used: the Lava Oral scanner and Cadent's iTero scanner. Digital scans were made of a first molar typodont tooth that was suitably prepared for an all-ceramic crown. The digital impressions were sent via the Internet to commercial dental laboratories, where the crowns were made. Also, an impression of the typodont tooth was made, poured, and scanned in order to evaluate the pre-cementation gap of crowns produced from scanning stone dies. These methods and systems were evaluated by creating replicas of the intermediate space using an addition-cured silicone, and the gap widths were determined using a measuring microscope. Hot-pressed leucite-reinforced glass-ceramic crowns were selected as a reference. The mean value for the marginal measuring points of the control was 170 μm, and the values for all the evaluated crowns ranged from 107 to 128 μm. Corresponding figures for the internal measuring points were 141-210 μm and 115-237 μm, respectively. Based on the findings in the present study, an in-office digital-impression technique can be used to fabricate CAD/CAM ceramic single crowns with a marginal and internal accuracy that is on the same level as that of a conventional hot-pressed glass-ceramic crown. In the present study, however, slight differences could be seen between the two types of ceramic crowns studied with respect to the internal fit obtained.



2018 ◽  
Vol 38 (3) ◽  
pp. e41-e48
Author(s):  
Saniye Halıcı ◽  
Canan Hekimoğlu ◽  
Orkun Ersoy


Author(s):  
Sílvia Fontes Do Amaral Pereira

O objetivo do presente estudo in vitro foi verificar, através de teste de cisalhamento, a resistência de união da liga Wironia®light, à base de níquel-cromo sem berílio, sujeita a diferentes tratamentos de superfície, às cerâmicas Vita VM13 e Noritake. Foram confeccionados oitenta espécimes cilíndricos metálicos, com o auxílio de uma matriz de aço, nas dimensões de 4 mm de diâmetro por 4 mm de altura. Os espécimes foram divididos em oito grupos (n=10), de acordo com o tipo de tratamento superficial aplicado à liga metálica e com o tipo de cerâmica testada. Estes foram avaliados de acordo com os critérios de resistência ao cisalhamento e, com o auxílio de microscopia óptica, foi avaliada a área de cerâmica remanescente aderida ao metal após a fratura. Os corpos-de-prova do G6 (fabricados em Cerâmica Noritake com jateamento-26,401 ± 11,637 MPa) apresentaram maior resistência ao cisalhamento (p> 0,05) enquanto que os menores valores foram registrados no G4 (Cerâmica Vita com utilização de broca-13,440 ± 7,766 MPa). G6 (19425,4 μm2) apresentou a maior área de cerâmica aderida ao metal (p> 0,05) enquanto que o G4 (2310,2 μm2) apresentou a menor área. Concluiu-se que G6 obteve os valores mais altos de resistência ao cisalhamento e de remanescente cerâmico aderido à superfície metálica enquanto que o G4 obteve os valores mais baixos. Descritores: Restaurações metalo-cerâmicas; ligas de níquel-cromo;porcelana dentária.



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