Effects of argon plasma and aging on the mechanical properties and phase transformation of 3Y-TZP zirconia.

To evaluate the flexural strength (FS) and flexural modulus (FM) of a commercial 3Y-TZ0P ceramic after artificial aging and either without or with two application times of non-thermal plasma treatments (NTP). In addition, changes in crystalline phase transformation and surface nano-topography after NTP application, during different aging periods, were evaluated. Ninety 3Y-TZP bars (45x4x3 mm) were made for FS and FM testing, and assigned to nine groups (n=10): no NTP/no aging (Control); no NTP/4h aging; no NTP/30h aging; 10s NTP/no aging; 10s NTP/4h aging; 10s NTP/30h aging; 60s NTP/no aging; 60s NTP/4h aging and 60s NTP/30h aging. Artificial accelerated aging was simulated using an autoclave (134º C at 2 bar) for up to 30h. FS and FM were assessed using a universal testing machine and data analyzed using a ANOVA and Tukey test (α=0.05). The volume change in zirconia monoclinic phase (MPV) was evaluated using X-ray diffraction and surface nano-topography was assessed using atomic force microscopy (baseline until 30h-aging). NTP application did not influence the FS and FM of zirconia. Compared to the Control (no NTP/no aging), the FS of zirconia samples treated for 30 hours in autoclave ("no NTP/30h aging" group) increased. Artificial aging for 30 hours significantly increased the FM of zirconia, regardless of NTP application. MPV tended to increase following the increase in aging time, which might result in the surface irregularities observed at 30h-aging. NTP did not alter the zirconia properties tested, but 30h-aging can change the zirconia FS, FM and MPV.

Effects of argon plasma and aging on the mechanical properties and phase transformation of 3Y-TZP zirconia

Abstract To evaluate the flexural strength (FS) and flexural modulus (FM) of a commercial 3Y-TZ0P ceramic after artificial aging and either without or with two application times of non-thermal plasma treatments (NTP). In addition, changes in crystalline phase transformation and surface nano-topography after NTP application, during different aging periods, were evaluated. Ninety 3Y-TZP bars (45x4x3 mm) were made for FS and FM testing, and assigned to nine groups (n=10): no NTP/no aging (Control); no NTP/4h aging; no NTP/30h aging; 10s NTP/no aging; 10s NTP/4h aging; 10s NTP/30h aging; 60s NTP/no aging; 60s NTP/4h aging and 60s NTP/30h aging. Artificial accelerated aging was simulated using an autoclave (134º C at 2 bar) for up to 30h. FS and FM were assessed using a universal testing machine and data analyzed using a ANOVA and Tukey test (α=0.05). The volume change in zirconia monoclinic phase (MPV) was evaluated using X-ray diffraction and surface nano-topography was assessed using atomic force microscopy (baseline until 30h-aging). NTP application did not influence the FS and FM of zirconia. Compared to the Control (no NTP/no aging), the FS of zirconia samples treated for 30 hours in autoclave ("no NTP/30h aging" group) increased. Artificial aging for 30 hours significantly increased the FM of zirconia, regardless of NTP application. MPV tended to increase following the increase in aging time, which might result in the surface irregularities observed at 30h-aging. NTP did not alter the zirconia properties tested, but 30h-aging can change the zirconia FS, FM and MPV.

Resumo Avaliar a resistência à flexão (FS) e o módulo de flexão (FM) de uma cerâmica comercial 3Y-TZP após envelhecimento artificial, e com ou sem dois tempos de aplicação de plasma não térmico (NTP). Além disso, a transformação de fase cristalina e a nano-topografia de superfície após a aplicação de NTP, durante diferentes períodos de envelhecimento, foram avaliadas. Noventa barras 3Y-TZP (45x4x3 mm) foram feitas para testes de FS e FM, e distribuídas em nove grupos (n=10): sem NTP/sem envelhecimento (Controle); sem NTP/4h de envelhecimento; sem NTP/30h de envelhecimento; 10sNTP/sem envelhecimento; 10sNTP/4h; 10sNTP/30h; 60sNTP/sem envelhecimento; 60sNTP/4h e 60sNTP/30h. O envelhecimento artificial acelerado foi simulado em autoclave (134º C a 2 bar) por até 30 horas. FS e FM foram avaliados em máquina de ensaio universal e os dados analisados ​​pela ANOVA e teste de Tukey (α = 0,05). A mudança de volume da fase monoclínica de zircônia (MPV) foi avaliada usando difração de raios-X e nano-topografia de superfície foi avaliada utilizando microscopia de força atômica (baseline até 30h). A aplicação do NTP não influenciou a FS e FM da zircônia. Comparado ao Controle ("sem NTP/sem envelhecimento"), a FS das amostras de zircônia tratadas por 30 horas em autoclave ("sem NTP/30h de envelhecimento") aumentou. O envelhecimento artificial por 30 horas aumentou significativamente a FM da zircônia, independente do tempo de aplicação do NTP. O MPV tendeu a aumentar em função do aumento do tempo de envelhecimento para todos os grupos, que pode ter resultado nas irregularidades superficiais observadas com 30 horas de envelhecimento. O NTP não afetou as propriedades da zircônia testadas, mas o envelhecimento por 30 horas pode alterar a FS, FM e MPV da zircônia.

Effect of argon plasma on repair bond strength using nanofilled and microhybrid composites.

OBJECTIVES: To evaluate the effect of atmospheric pressure plasma (PLA), sandblasting (SAN), silanization (SIL) and hydrophobic bonding resin (HBR) on the micro-shear bond strength (MSBS) of fresh nanofilled (NF) or microhybrid (MH) composites to water-aged nanofilled composite. MATERIALS AND METHODS: NF plates were fabricated and stored in distilled water for 4 months. The aged plates were assigned to the groups (n = 6): 1- untreated; 2- SAN + SIL + HBR; 3- HBR; 4- PLA + HBR; 5- SAN + HBR; 6- SAN + PLA + HBR; and 7- PLA. Two fresh composite cylinders were constructed on each plate with NF or MH composites and tested after 24 h or 1 year of water-storage, using the MSBS testing. Data were analyzed by three-way ANOVA and Tukey test (α = 0.05). RESULTS: NF yielded better outcomes than MH at 24 h, which was not observed at 1 year. HBR showed the highest MSBS results, while untreated and PLA groups yielded the lowest one. MSBS reduced for all groups after 1 year. CONCLUSIONS: Only HBR can obtain good MSBS results, while PLA alone was not beneficial. After 1 year, a reduction in repair MSBS was observed and the type of composite did not influence the results. CLINICAL RELEVANCE: The repair technique can be simplified with the use of only an adhesive and macromechanical retentions in the old composite, regardless the type of fresh composite.

Effect of aluminum oxide sandblasting, plasma application and their combination on the bond strength of resin cement to zirconia ceramics / Efeito do jateamento de óxido de alumínio, aplicação de plasma e sua combinação na resistência de união do cimento resinoso à zircônia

Objective: to evaluate the effect of aluminum oxide sandblasting (AOS), argon plasma application (APL) and their combination (AOS+APL) on the shear bond strength (SBS) of dual-cure resin cement (Panavia F 2.0, Kuraray Noritake) to two zirconia-based ceramics (Lava, 3M ESPE and Katana, Kuraray Noritake). Material and Methods: One hundred twenty zirconia plates (13 mm in length X 5 mm in width X 1 mm in thickness) were prepared and treated according to the following treatments: 1- AOS, 2- APL,3- AOS+APL and 4- no treatment (control). After treatments, resin cement cylinders (1.4 mm in diameter x 1 mm in height) bonded to zirconia surface were obtained by filling up the silicon matrix. The shear bond test was performed following storage of the samples for 24 hours and one year. Bond strength values were recorded in MPa and the data were analyzed by three-way ANOVA and Tukey post-hoc test (preset alpha of 0.05). Results: In general, AOS and AOS +APL showed the higher SBS. After one-year storage, SBS of the resin cement to the Katana zirconia did not reduce, regardless of the zirconia surface treatment. Conclusion: AOS alone was able to increase the SBS of the resin cement to both zirconia ceramics compared to control and SBS remained stable after one year depending on type of zirconia ceramic. (AU)

Objetivo: avaliar o efeito do jateamento de óxido de alumínio (AOS), aplicação de plasma de argônio (APL) e sua combinação (AOS + APL) na resistência ao cisalhamento (SBS) do cimento resinoso dual (Panavia F 2.0, Kuraray Noritake) a duas cerâmicas à base de zircônia (Lava, 3M ESPE e Katana, Kuraray Noritake). Material e Métodos: Cento e vinte placas de zircônia (13 mm de comprimento X 5 mm de largura X 1 mm de espessura) foram preparadas e tratadas de acordo com os seguintes tratamentos: 1- AOS, 2- APL, 3- AOS + APL e 4 - sem tratamento (controle). Após realizados os tratamentos, com a utilização de uma matriz de silicone (1,4 mm de diâmetro x 1 mm de altura) foram confeccionados cílindros de cimento resinoso na superfície da zircônia. O teste de cisalhamento foi realizado após o armazenamento das amostras por 24 horas e um ano. Os valores de resistência de união foram registrados em MPa e os dados foram analisados por ANOVA de três fatores e teste post-hoc de Tukey (alfa de 0,05). Resultados: Em geral, AOS e AOS + APL apresentaram a maior SBS. Após um ano de armazenamento, o SBS do cimento resinoso para a zircônia Katana não reduziu, independentemente do tratamento da superfície da zircônia. Conclusão: AOS isoladamente foi capaz de aumentar a SBS do cimento resinoso para ambas as zircônias em comparação com o controle e a SBS permaneceu estável após um ano, dependendo do tipo de zircônia. (AU)

Effect of cleaning agent, primer application and their combination on the bond strength of a resin cement to two yttrium-tetragonal zirconia polycrystal zirconia ceramics.

OBJECTIVE: The objective of this study is to evaluate the effect of a cleaning agent and priming on the bond strength (BS) of a resin cement (RC) to zirconia ceramics after 24 h and 1 year of water-storage. MATERIALS AND METHODS: Fifty-six Katana and 56 ZirCAD zirconia ceramic plates were prepared and each zirconia brand was divided into four groups (n = 14): (1) untreated; (2) treated with Ivoclean cleaning agent; (3) treated with Monobond Plus coupling agent; (4) treated with Ivoclean + Monobond Plus. Cleaning and coupling agents were applied to zirconia following the manufacturers' instructions. The RC was manipulated, inserted into tubes (0.75 mm diameter/1 mm height) that were positioned on the zirconia surfaces and light activated. Specimens were tested after 24 h and 1 year of water storage. A shear load was applied to the base of the RC cylinders (until failure. Data were analyzed by three-way ANOVA and Tukey tests (α = 5%). RESULTS: No significant difference in BS was noted between zirconia ceramics, except when the combination of cleaning and coupling agents was used. This combination increased the BS for Katana zirconia. One year of water storage leads to a decrease in BS for all experimental groups. CONCLUSION: The combination of cleaning agent and priming can yield higher BS for Katana at 24 h. BS to zirconia ceramics reduced approximately 50% after 1 year.