Effect of 0.2% peracetic acid disinfection on the horizontal dimension of implant framework indexed with two autopolymerized acrylic resins.

BackgroundTo 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 methodsIFPD 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.ResultsNo 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).ConclusionWithin 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

Efeito da carga cíclica na resistência de dentes tratados endodonticamente restaurados com pinos dentários convencionais e estéticos

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

Influence of test parameters on in vitro fracture resistance of post-endodontic restorations: a structured review

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75093/1/j.1365-2842.2009.01940.x.pd

Fracture strength and fractographic analysis of zirconia copings treated with four experimental silane primers

This study evaluated and compared the effect of new four experimental silane coupling agents on the fracture strength of zirconia copings. The findings were supported with fractographic and finite element analyses. All together 125 zirconia copings with a ?wall thickness of 0.6mm were fabricated on identical nickel-chromium master dies and then divided randomly into five groups (n=25). Four test groups were prepared according the experimental silane primer (labeled: OIWA1, OIWA2, OIWA3 and OIWA4) ?and one control group without silanization. The silane monomers used were: ?3-methacryloxypropyltrimethoxysilane (in OIWA1), ?3-acryloxypropyltrimethoxysilane (in OIWA2), ?3-?isocyanatopropyltriethoxysilane (in OIWA3) and styrylethyltrimethoxysilane (in OIWA4). Tribochemical sandblasting (silica-coating) treatment was performed to the inner surface of the copings in the ?test groups. All the specimens were silanized at the inner surfaces of the zirconia copings. Self-?adhesive universal resin cement was used to cement the copings to ?the underlying master die. Zirconia copings were vertically loaded on the ?cusp ?area until the first crack failure was occurred using Precision Universal Tester ?at a ?constant crosshead speed of 1mm/min. Then, the machine ?was manually controlled to cause more failure ?to further determine the texture of fracture. Three dimensional finite element analysis and fractography were performed to support the fracture strength findings. Based on the finite element analysis results, zirconia silanized with ?3-acryloyloxypropyltrimethoxysilane showed the highest fracture strength with a mean of ?963.75?N (SD 4.5N), while zirconia copings silanized with ?3-methacryloyloxypropyltrimethoxysilane showed a mean fracture strength value of ?925.65N (SD 2.4N). Styrylethyltrimethoxysilane-silanised zirconia showed mean fracture strength of 895.95N (SD 3.5N). Adding silane coupling agents to the resin-zirconia interface increased the fracture strengths significantly (ANOVA, p<0.05). Silanization with four new experimental silane primers in vitro produced significantly ?greater fracture strength than the control group not treated with the test silane.

Avaliação da resistência ao cisalhamento de três sistemas de núcleos intra-radiculares

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

Efeito de cargas cíclicas na resistência à fratura de dentes tratados endodonticamente reconstruídos com pinos pré-fabricados estéticos e metálicos restaurados com coroas de porcelana pura.

Foram avaliados, in vitro, o efeito da aplicação de carga cíclica na resistência à fratura, a resistência à fratura, modo de fratura e associação entre as dimensões MD e VL com resistência à fratura de dentes reconstruídos com sistemas de pinos pré-fabricados metálicos convencionais e estéticos, restaurados com coroas de porcelana pura, submetidos à fadiga térmica e mecânica através de teste à compressão com carga estática. Sessenta caninos íntegros tiveram suas coroas amputadas 1,5mm acima da junção cementoesmalte e preparados para coroa de porcelana pura. Os dente foram distribuídos em 6 grupos de 10 dentes. Os grupos 1 e 2 foram restaurados com pinos pré-fabricados de cerâmica de zircônia Cosmopost (Ivoclar-Vivadent) e núcleo de preenchimento em cerâmica vítrea termo-injetada IPS Empress Cosmo Post (Ivoclar-Vivadent). Os grupos 3 e 4 foram restaurados com pinos pré-fabricados de resina composta reforçada por fibra de vidro FibreKor (Jeneric Pentron) e os grupos 5 e 6 com pinos de titânio AZthec Anchor Titanium (Dentatus). Nos grupos 3, 4, 5 e 6 foi usada resina composta reforçada com fibra de vidro Build It FR Fiber Reinforced Core (Jeneric Pentron) como material para núcleo de preenchimento; os dentes foram restaurados com coroas totais IPS Empress 2 (Ivoclar-Vivadent); tanto os pinos quanto as coroas de porcelana foram cimentados com o sistema resinoso de polimerização dupla Cement It / Bond It Primer A + B (Jeneric Pentron). Os espécimes foram submetidos à ciclagem térmica por 300X, em temperaturas de 5°C e 55°C e incluídos em resina acrílica em blocos de alumínio. Os grupos 2, 4 e 6 foram submetidos à uma carga cíclica de 250N por 500,000X, a uma freqüência de 1,7Hz. Os 6 grupos foram submetidos à carga estática em uma máquina de testes universal até falha dos sistemas. Após a carga estática os espécimes foram avaliados quanto ao modo de fratura e classificados em 02 tipos: Supra-crestal (SC) - quando a fratura se localizou até 1mm abaixo da linha de inclusão dos espécimes na resina acrílica ou Infra-crestal (IC) - quando a linha de fratura se localizou 1,1mm ou mais, abaixo da linha de inclusão dos espécimes na resina acrílica. Os dados foram analisados estatisticamente com os testes ANOVA a 2 critérios, Tukey, Correlação de Pearson, Q Quadrado (&#967;2) e Exato de Fischer. Na análise da resistência à fratura, o valor do grupo 1 (1165,5±211,95N) foi maior do que o grupo 2 (886,50±170,62N); o do grupo 3 (1041,50±231,20N) foi maior do que o do grupo 4 (762,20±113,63N) e o do grupo 5 (768,90±72,95N) foi maior do que o do grupo 6 (985,40±99,89N) (p<0.05). O valor do grupo de pinos de zircônia foi significantemente maior do que os grupos de pinos de resina composta reforçados por fibras de vidro e titânio (p<0.05), que foram iguais entre si (p=0,146) independente da aplicação da carga cíclica (p<0,05). A carga cíclica diminuiu significantemente a resistência dos dentes restaurados (p<0,05). Houve fraca, porém significante relação entre a dimensão MD e resistência à fratura dos espécimes (r=0,260 e p=0,044). Na análise do modo de fratura, o grupo 1 apresentou 30% de fraturas SC e 70% IC; o grupo 2 apresentou 60% de fraturas SC e 40% IC; o grupo 3 apresentou 60% de fraturas SC e 40% IC; no grupo 4 houve 90% de fraturas SC e 10% de IC; no grupo 5 houve 40% de fraturas SC e 60% de IC enquanto no grupo 6, 50% de fraturas SC e 50% IC. Não houve correlação entre o tipo de pino e modo de fratura (&#967;2=0,484 e p=0,885), independente do uso de carga cíclica. Em conclusão, os dentes restaurados com pinos de zircônia e núcleos de preenchimento de porcelana vítrea apresentaram os melhores valores de resistência à fratura, independente da aplicação de carga cíclica, entre os grupos testados; o tratamento com carga cíclica reduziu significantemente a resistência em todos os grupos testados. Não houve diferença de resistência à fratura entre os grupos restaurados com resina composta reforçado por fibra de vidro e titânio, independente da aplicação da carga cíclica. Não houve correlação entre o tipo de pino e o modo de fratura, e, quanto maior a dimensão MD dos espécimes, maior a força necessária para levá-los à fratura.This study compared the effect of cyclic load, survival rate, residual strength, the mode of fracture and relationship between MD and BL dimensions and strength of endodontically treated teeth restored with three esthetic post systems subjected to thermal and mechanical cyclic load. Sixty canines were selected for the study. They were endodontically treated with guta percha points and calcium hydroxide cement (Sealapex Kerr), decoronated 1.5mm above the cementum enamel junction and prepared for metal free ceramic crowns (1.0mm in BL and 0.8mm in MD direction and rounded shoulder), leaving a remaining dentin amount of 1.5mm high as ferrule effect. After BL, MD dimensions were obtained, they were distributed in 6 groups according to the stratified method. Groups 1 and 2 were restored with 1.7mm in diameter zirconia posts (Cosmopost Ivoclar Vivadent) and heat pressed glass-ceramic cores (IPS Empress Cosmo Ivoclar Vivadent); groups 3 and 4 were restored with 1.5mm in diameter fiber reinforced composite posts (FibreKor Jeneric Pentron) and group 5 and 6 were restored with 1.65mm in diameter titanium posts (AZthec Anchor Dentatus). Direct resin composite (Build It FR Jeneric Pentron) were used as cores for the 4 latest groups. All specimens were restored with all ceramic crowns (Empress 2 Ivoclar). In all groups, 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. Twenty-four hours after cementing the crowns, the specimens were subjected to 300x thermal cycles with temperature ranging from 5°C to 55°C with 30sec of dwell time. Specimens were then embedded in resin acrylic, mounted in aluminum blocks. Groups 2, 4 and 6 were subjected 500.000x to a mechanical load of 250N in a frequency of 1.7Hz. All specimens were set in an Instron machine and subjected to static load until failure. Data were recorded and analyzed using Two-way ANOVA,Tukey, Pearson Correlation, Chi Square and Exact Fischer tests. Group 1 (1165.7±210.95N) was higher than group 2 (886.50±170.62N); group 3 (1041.50±231.20N) was higher than group 4 (762.20±113.63N) and group 5 (985.40±99.89N) was higher than group 6 (768,90±72.95 N). Zirconia group values were higher than all the other groups (p<0.05); there was no statistically difference between fiber reinforced composite and titanium group even after the cyclic loading (p=0.146); cyclic loading reduced significantly the fracture strength of all groups (p<0.00); there was no correlation between type of posts and decrease in fracture strength (p=0.778); there were a weak but significant correlation between MD specimens dimension and load to failure (r=0.260 e p=0.044); there was no correlation between the mode of failure and type of posts (&#967;2=4.484 e p=0.885). It was concluded that: 1-Teeth restored with zirconia posts and glass-ceramic cores showed the highest strength to fracture, regardless the cyclic loading application; 2- The cyclic loading treatment lowered the fracture strength of all groups tested; 3- Fiber reinforced composite posts group values were not significantly different from titanium posts regardless the cyclic loading application; 4- Larger MD dimension may favor an increase in the fracture strength of teeth restored with pre-fabricated post systems

Effect of cyclic loading on fracture strength of endodontically treated teeth restored with conventional and esthetic 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

Influence of polishing systems on roughness and color change of two dental ceramics

Made available in DSpace on 2019-09-20T14:08:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2019PURPOSE. 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<.05). With exception for PG and CG subgroups, which did not present statistical difference between them, all other pressed ceramics subgroups presented smaller Ra values and greater Delta E values than the layering ceramics subgroups (P<.05). CONCLUSION. Although mechanical polishing systems presented intermediate Ra values, their colors were considered clinically acceptable. There is a strong correlation between the surface roughness and the color change of tested ceramics.[Maciel, Lucas Campagnaro; da Silva Concilio, Lais Regiane] Univ Taubate UNITAU, Dent Sch, Taubate, SP, Brazil[Bettcher Silva, Carlos Frederico] Sch Higher Educ Sao Francisco Assis ESFA, Dent Sch, Santa Teresa, ES, Brazil[de Jesus, Ricardo Huver] Univ Veiga de Almeida, Dent Sch, Rio de Janeiro, RJ, Brazil[Kano, Stefania Carvalho; Xible, Anuar Antonio] Fed Univ Espirito Santo UFES, Dent Sch, Vitoria, ES, Brazi