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Introdução: O Cimento de Ionômero de Vidro (CIV) é de grande aplicabilidade no controle da doença cárie e no Tratamento Restaurador Atraumático. Objetivos: Avaliar o efeito da adição de liga de prata na resistência à compressão (RC) e à tração diametral (RTD) de CIVs. Métodos: Utilizando duas diferentes matrizes de nylon, foram confeccionados 34 corpos de prova em forma de cilindro para cada grupo, sendo 17 com 4mm de diâmetro e 6mm de altura para o teste de RC e 17 com 4mm de diâmetro e 2mm de altura para RTD. O grupo G1 foi constituído de Maxxion R®, o G8-Riva Silver® e G9-Riva Self Cure®. Os grupos G2 e G7 foram compostos de Maxxion R®+Velvalloy® em diferentes proporções do composto de prata: G2-16.6%, G3-22.0%, G4-28.5%, G5-53.3%, G6- 60.4% e G7-69.3%. Os corpos de prova foram submetidos aos testes mecânicos em máquina de ensaio universal (EMIC-DL-2000), a uma velocidade de 1,0mm/min. Os dados foram submetidos ao tratamento estatístico usando os testes ANOVA One-Way e Duncan (p

Effect of insertion technique in the mechanical resistance of two High viscosity glass ionomer cements

Background To minimize misfit between prosthesis and implant, the welding of the implant fixed partial denture (IFPD) framework is recommended and autopolymerized acrylic resin (AR) is the material of choice for the indexing process. As for any prosthetic device that comes into contact with saliva and blood in the oral cavity, IFPD indexed with AR must be disinfected before sending to the laboratory. However, disinfection procedures are often neglected for fear of shrinkage or distortion caused by a dimensional change of the acrylic resin. Peracetic acid is a high-level disinfectant agent at low concentrations and immersion time, with no reported toxic residues, and it is not inactivated in the presence of organic matter when compared to other disinfectants. This study aimed to evaluate the influence of 0.2% peracetic acid disinfectant solution after different storage media and times on the horizontal dimension of IFPD frameworks indexed with AR. Material and methods IFPD frameworks were indexed with two AR: group 1 Duralay and group 2 Pattern Resin LS. Each group was further divided into five subgroups according to disinfection procedure and storage medium: no disinfection and dry storage, no disinfection and water storage, 0.2% peracetic acid disinfection and water storage, 0.2% peracetic acid disinfection and peracetic acid storage, and 0.2% peracetic acid disinfection and dry storage. The horizontal dimension of the specimens and an average was established for analysis. Measurements were performed at four different storage times (hours): T0, T24, T48, T168. Results No statistical differences were found when T0 was compared to T168 for Pattern resin groups submitted to disinfection and storage in water (group 2b, p = 1.000) or peracetic acid solution (group 2c, p = 0.352). For Duralay groups, the use of peracetic acid solution did not affect the horizontal dimension of the specimens when T0 was compared to T168 only with water as a storage medium (group 1b, p = 1.000). Additionally, T0 did not differ from T24 for groups 1c (p = 0.553), 2b (p = 1.000), 2d (p = 0.234), and 2e (p = 1.000) and from T48 for groups 1d (p = 0.118) and 2b (p = 1.000). Conclusion Within the studied conditions, the use of 0.2% peracetic acid can be safely used as a disinfectant solution regarding dimensional stability of AR-indexed IFPD until 7 days of storage. Horizontal discrepancies are dependent on acrylic resin type, time, and medium of storage.

Made available in DSpace on 2019-09-20T14:08:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2019 PURPOSE. To evaluate the polishing effect on roughness and color change of pressed and layering ceramics after immersion in coffee solution. MATERIALS AND METHODS. 88 ceramic discs (1.0 mm x 10.0 mm) were manufactured - 44 nano-fluorapatite layering ceramics (IPS e.max Ceram. Group C) and 44 pressed lithium disilicate ceramic discs (IPS e. max Press - Group P). Each group was divided into 4 subgroups according to surface treatments: (G) Glaze, (S) Shofu polishing system (Shofu Inc.), (E) Edenta AG polishing System, (KG) 30-pm diamond granulation tip. Surface roughness (Ra) and color change (Delta E) measurings after the surface treatments were performed, before and 12 days after the immersion in coffee solution. A sample's qualitative analysis was conducted with a scanning electron microscopy (SEM). Data were statistically-treated with oneway-ANOVA and Duncan's tests, apart from paired t-test and Pearson's correlation test (alpha=5%). RESULTS. The decrescent order, both for surface roughness (Ra) and Delta E for both ceramics were: KG > E > S > G (P

OBJECTIVES: The purpose of this in vitro study was to evaluate misfit alterations at the implant/abutment interface of external and internal connection implant systems when subjected to cyclic loading. MATERIAL AND METHODS: Standard metal crowns were fabricated for 5 groups (n=10) of implant/abutment assemblies: Group 1, external hexagon implant and UCLA cast-on premachined abutment; Group 2, internal hexagon implant and premachined abutment; Group 3, internal octagon implant and prefabricated abutment; Group 4, external hexagon implant and UCLA cast-on premachined abutment; and Group 5, external hexagon implant and Ceraone abutment. For groups 1, 2, 3 and 5, the crowns were cemented on the abutments and in group 4 crowns were screwed directly on the implant. The specimens were subjected to 500,000 cycles at 19.1 Hz of frequency and non-axial load of 133 N in a MTS 810 machine. The vertical misfit (μm) at the implant/abutment interface was evaluated before (B) and after (A) application of the cyclic loading. Data were analyzed statistically by using two-away ANOVA and Tukey's post-hoc test (p

No presente estudo in vitro, avaliou-se a quantidade de torque gerada pelos torquímetros: Nobelpharma de 20 e 32 N/cm (Nobel Biocare / Sweden) (1A e 1B), Torque Driver 3I de 20 e 32 N/cm (Implant Innovations / USA) (2A e 2B), Torque-Lock em 20 30 N/cm (Intra-Lock / USA) (3A e 3B) e Dyna de 20 e 30 N/cm (Dyna Torq / USA) (4A e 4B), em dez parafusos UCLA titânio (3I implants innovations REF UNIH / USA T). Mediu-se a quantidade de torque necessária para o afrouxamento do parafuso após o torque com cada torquímetro, utilizando-se um medidor analógico de torque (TOHNICHI BTG60CN / JAPAN). Os resultados mostraram diferenças estatisticamente significantes nos torquímetros 1A e 2A com os torquímetros 3A e 4A. Houve também diferenças estatisticamente significantes entre os torquímetros 1B e 2 B, assim como entre os torquímetros 3B e 4B. Alem disso, encontraram-se diferenças no torque produzido e o torque programado nos torquímetros 3A e 3B, e 4A e 4B, concluindo-se que os torquímetros eletrônico Nobelpharma e 3I de 20 e 32 N/cm geram a quantidade de torque para a qual são programados enquanto que os torquímetros Torque Lock e Dyna de 20 e 30 N/cm não geram a quantidade de torque para o qual são programados.

The bond strength of composite resin cores to the smooth surface of prefabricated zirconia-based ceramic posts is problematic because it might not be sufficient to ensure stability of the post-and-core system. It is also not clear whether any alteration of the post surface to provide additional mechanical or chemical retention would compromise flexural strength of the posts.This study tested the effect of a tribochemical treatment on the bond strength (BS) between zirconia-based ceramic posts and composite resin and on the flexural strength (FS) of the posts.For the BS test, 2 groups of specimens (n = 10) were prepared as follows: In the experimental (E) group, zirconia-based ceramic posts (Cosmopost), 21 mm long and 1.7 mm in diameter, were treated with a tribochemical silica coating and silanization system (Rocatec). For the control (C) group, zirconia-based ceramic posts were used as supplied by the manufacturer. For the 2 groups, posts were centered and vertically positioned in a metal mold, and composite resin (Tetric Ceram) was polymerized around the posts to form rings (6 mm diameter x 4 mm height). All specimens were positioned in a universal testing machine, and a load was applied axially on the protruding heads of posts in a shear push-out mode test until bond failure (MPa). Fracture mode was assessed as cohesive, cohesive/adhesive, or adhesive. Following this, the FS of the posts was measured in MPa using a 3-point bending test. Data were recorded and statistically analyzed using the Student t test for both tests (alpha = .01).Mean fracture load values +/- SDs for the BS test were 28.1 +/- 2.3 MPa and 8.9 +/- 3.97 MPa for the E and C groups, respectively. The mean FS values were 1544.9 +/- 214.1 MPa and 844.8 +/- 50.8 MPa for the E and C groups, respectively. The tribochemically treated posts exhibited significantly higher values for both bond strength to composite resin and resistance to fracture when compared to posts in the control group (P.001). Fracture analysis showed 100% cohesive/adhesive fractures for group E specimens and 100% adhesive fractures for group C specimens.The use of a tribochemical silica coating process and silanization on zirconia-based ceramic posts increased both the bond strength to composite resin as well as the fracture strength of posts.

INTRODUCTION: Esthetic post and core systems were recently introduced. There are few reports regarding their behavior under cyclic loading. OBJECTIVES: This study compared the effect of cyclic loading on survival rate, residual strength and mode of fracture of endodontically treated teeth restored with esthetic and direct metallic post systems subjected to mechanical cyclic loading. MATERIALS AND METHODS: Thirty canines were endodontically treated, decoronated and prepared for metal free ceramic crowns, leaving 1.5 mm of dentin for ferrule effect. They were distributed in 3 groups and restored as follows: group 1 with zirconia posts (Cosmopost) and glass-ceramic cores (IPS Empress Cosmopost); group 2 with fiber reinforced composite posts (FibreKor) and group 3 with titanium posts (AZthec Anchor). Direct resin composite (Build It FR Resin Composite) was used as core in groups 2 and 3. All specimens were restored with all ceramic crowns (IPS Empress 2). A resin cement/adhesive system (Cement It/Bond It Primer A+B) was used to lute the posts to root canals and metal free porcelain crowns to the teeth preparation. Specimens were subjected to mechanical load of 250 N for 500,000x at a frequency of 1.7 Hz and then to static load until failure in a universal testing machine. Data were analyzed using One-way ANOVA and Fischer Exact tests alpha=0.05. RESULTS: All groups had 100% survival rate after cyclic loading; fracture strength values (SD) in N were: group 1 = 886.5(170.6), group 2 = 762.2(113.6) and group 3 = 768.9(72.9); there was no difference among groups (p=0.08); the percentage of mode of favorable fracture found was: group 1 = 60%, group 2 = 90% and group 3 = 50%; there was no correlation between the mode of failure and post and core system used (P=0.142). CONCLUSIONS: Esthetic post and core systems showed statistically equivalent fracture strength values, mode of failure and survival rate compared to conventional direct metallic post and resin composite core system after cyclic loading. INTRODUÇÃO: Os sistemas de núcleos intra-radiculares estéticos foram recentemente introduzidos no mercado. Não existem muitos trabalhos na literatura comparando seu comportamento em relação aos sistemas de pinos metálicos convencionais quando submetidos à testes com carga cíclica. OBJETIVOS: este estudo comparou a taxa de sobrevivência, resistência à fratura e modo de fratura de dentes tratados endodonticamente reconstruídos com sistemas de núcleos intra-radiculares metálicos convencionais e estéticos, restaurados com coroas de porcelana pura e submetidos à carga cíclica. MATERIAIS E MÉTODOS: trinta caninos tiveram as coroas removidas 1,5mm acima da junção cemento-esmalte e preparados para coroa de porcelana pura deixando 1,5mm de dentina acima do término do preparo. Os dentes foram distribuídos em 3 grupos de 10. O grupo 1 foi restaurado com pinos de cerâmica de zircônia e núcleos de preenchimento em cerâmica vítrea termo-injetada. O grupo 2 foi restaurado com pinos de resina composta reforçada por fibra de vidro e o grupo 3 com pinos de titânio. Nos grupos 2 e 3 foi usada resina composta reforçada com fibra de vidro como material para núcleo de preenchimento; os dentes foram restaurados com coroas totais e tanto os pinos quanto as coroas de porcelana foram cimentados com um sistema de cimentação resinosa de polimerização dupla. Os espécimes foram incluídos em resina acrílica e submetidos à uma carga de 250N por 500,000 ciclos, numa freqüência de 1,7Hz sendo em seguida submetidos à carga estática em uma máqina de testes universal até a falha. Os dados foram analisados estatisticamente com os testes ANOVA a 1 critério e Exato de Fischer (alfa=.05). RESULTADOS: a taxa de sobrevivência foi de 100%; os valores de resistência à fratura em N (DP) foram: grupo 1 = 886,50(170,6), grupo 2 = 762,2(113,6) e grupo 3 = 768,9(72,9). Não houve diferença estatística de resistência à fratura entre os grupos (P=0.08). O percentual de modo de fratura favorável encontrado foi: grupo 1 = 60%; grupo 2 = 90% e grupo 3 = 50%. Não houve correlação entre o tipo de pino e modo de fratura (P=0.142). CONCLUSÃO: dentes restaurados com sistemas de núcleos intra-radiculares estéticos e coroas totais de porcelana tiveram as mesmas taxas de sobrevivência, valores de resistência à fratura e modo de fratura que os metálicos convencionais diretos após aplicação de carga cíclica.

Foram comparadas as resistências adesivas ao cisalhamento presente entres os componentes de três diferentes sistemas de núcleos intra-radiculares. Foram utilizados pinos de cerâmica à base de dióxido de zircônia ( Cosmopost ), e pinos de titânio ( Tenax ). Os preenchimentos testados foram a resina composta fotopolimerizável ( Tetric Ceram ) e porcelana vítrea fundível ( IPS Empress Post ). Foram confeccionados 30 espécimes divididos em 03 grupos: 10 espécimes de pinos de cerâmica à base de zircônia, aos quais foi fundida porcelana vítrea; 10 espécimes de pinos de cerâmica à base de zircônia e resina composta fotopolimerizável; e 10 espécimes de pinos de titânio e resina composta fotopolimerizável, todos, de acordo com o fabricante. Os espécimes do grupo 1 necessitaram ser ajustados, por desgaste, à base de prova. Todos foram submetidos a uma força de cisalhamento em uma máquina de ensaios universal Kratos, até fratura. A análise estatística, assim como observações macroscópicas permitiu-nos concluir que: 1- A resistência encontrada entre os componentes dos corpos de prova do grupo Pino de Zircônia X Cerâmica IPS Empress Post apresentou resultados estatisticamente não significantes em relação ao grupo em que foi usado Pinos de Titânio X Resina composta. 2- Os resultados dos sistemas do grupo 1 - Pino de Zircônia X Cerâmica IPS Empress Post - e 3 - Pinos de Titânio X Resina Composta demonstraram diferença estatisticamente significante em relação ao grupo 2, em que foi empregado o sistema dos Pinos de Zircônia X Resina Composta. The purpose of the present study was to evaluate shear bond strength in three different posts and core systems. Thirty standardized cylindrical cores with 4mm height and 6mm diameter were prepared surrounding the posts in a special prefabricated device. They were divided in three groups. Group 1 was composed of 10 zirconia posts ( Cosmopost – Ivoclar ), which were placed in a special device. Cylinders were waxed surrounding them. The patterns were then invested and glass-ceramic ( Empress Cosmo – Ivoclar ) was heat-pressed in a EP500 furnace ( Ivoclar ). Group 2 consisting of 10 zirconia posts ( Cosmopost – Ivoclar ) adapted in the device and composite ( Tetric Ceram – Ivoclar ) was inserted and then light activated. Group 3 consisting of titanium posts ( Tenax – Whaledent ) was adapted in the same device as group 1 and 2. The same composite was inserted and also light activated. Specimens were tested for shear bond strength in a Kratos universal test machine. Results showed no statistical differences between groups 1 and 3 but significant difference between group 2 and the others. According to above results, it was concluded that systems used in groups 1 and 3 are the most reliable in clinical applications.