INIBIÇÃO DA COLONIZAÇÃO DE STAPHYLOCOCCUS E CANDIDA APÓS A ADIÇÃO DE AGENTES ANTIMICROBIANOS EM CONDICIONADOR TECIDUAL

Esse estudo teve por objetivo avaliar a efetividade a longo prazo da incorporação de agentes antimicrobianos em um condicionador tecidual (Softone-Bosworth Co, IL, EUA) na inibição de colonização bacteriana (Staphylococcus aureus-Sa) e fúngica (Candida albicans-Ca). As doses dos agentes incorporados ao pó do material (6 g) foram: sem adição de droga-controle (G1); nistatina-500.000 U (G2) e 1.000.000 U (G3); miconazol-125 mg (G4) e 250 mg (G5); cetoconazol-100mg (G6) e 200mg (G7); diacetato de clorexidina a 5% (G8) e diacetato de clorexidina a 10% (G9). As amostras (n=144) (10 x 1 mm) foram colocadas em placas de ágar Mannitol Salt para Sa e de ágar Sabourand para Ca previamente semeadas, as quais foram incubadas a 37ºC por 14 dias para a mensuração diária dos halos de inibição. Os dados foram submetidos à ANOVA e teste de Tukey (α=0,05). Para Ca, as maiores médias de halos de inibição foram obtidas para G7 (22,2 mm) e G6 (20,2 mm) e as menores para G2 (12,2 mm) (P<0,05). Houve inibição fúngica por 14 dias nos grupos G4, G5, G6 e G7 (13,8-20,6; 15,8-22,8; 16,4-23 e 19,2-25,4 mm, respectivamente). G3 (10,4-17 mm) apresentou inibição de Ca por 13 dias; G9 (10,8-17,2 mm) e G2 (10,4-16 mm) por 12 dias e G8 (11-16,8 mm) por 11 dias. Para Sa, as maiores médias de halos de inibição foram obtidas para G8 (19,2 mm) e G9 (13,6 mm) e as menores para G2 (10,2 mm) (P<0,05). No G8, houve inibição de Sa por 14 dias (1,8-9,0 mm) e no G9 por 12 dias (10,8-17,2 mm). O Sa foi inibido por 2 dias nos grupos G3, G4, G5, G6 e G7 (12,2-13,8; 12-13,8; 12,6-13,6; 12,8-13,6; 13,6-14,2 mm, respectivamente) e por 1 dia no G2 (12,6 mm). Não houve inibição de Ca e Sa no G1. Quando incorporados ao condicionador tecidual, a clorexidina e o cetoconazol foram, a longo prazo, os agentes antimicrobianos mais efetivos na inibição de Sa e Ca, respectivamente

EFEITO DA ADIÇÃO DE AGENTES ANTIMICROBIANO/ANTIFÚNGICO SOBRE DUREZA E RUGOSIDADE SUPERFICIAL DE CONDICIONADOR TECIDUAL

O objetivo desse estudo foi determinar o efeito da incorporação de antifúngicos (nistatina- N, miconazol- M ou cetoconazol- K) ou de agente antimicrobiano (diacetato de clorexidina-C) sobre propriedades físicas de um condicionador de tecido (Softone-S). Foi avaliado o padrão de incorporação destas drogas no material S por MEV/EDS. Os grupos avaliados foram: G1 = controle (sem adição de droga); G2 = N-500.000 U; G3 = N-1.000.000 U; G4 = M-125 mg; G5 = M-250 mg; G6 = K-100 mg; G7 = K-200 mg; G8 = C-5% e G9 = C-10% em relação à quantidade total (6 g) de S. As quantidades das drogas (em pó) foram misturadas ao pó de S, sendo o líquido de S posteriormente adicionado à mistura. Amostras (n = 5) foram plastificadas à temperatura ambiente por 10 min. As leituras de dureza (Shore A) e rugosidade (Ra) foram realizadas após imersão das amostras em água destilada a 37°C por 24 h, 7 e 14 dias. Os resultados foram analisados pela análise de variância (2-ANOVA)/ Tukey (α = 0,05). Após todos os períodos avaliados (24 h, 7 e 14 dias), a dureza dos grupos experimentais foi superior (P 0,05) à do G1 (5,83 µm). Após 14 dias, a rugosidade do G5, G8 e G9 foi superior (P < 0,05) (7,93; 9,63 e 10,29 µm, respectivamente) à do G1 (6,92 µm). O material modificado demonstrou morfologia favorável, por meio de MEV/EDS, para liberação intra-bucal das drogas avaliadas. Foram observadas alterações nas propriedades físicas do material modificado, entretantodeve-se avaliar se são clinicamente significantes

Influência de tratamentos superficiais e termociclagem na resistência da união resina/metal

Este estudo teve como objetivo avaliar a efetividade de quatro condicionadores de metal (Metal Photo Primer, MPP; Cesead II Opaque Primer, OP; Targis Link, TL e Siloc, S) aplicados sobre diferentes superfícies das ligas de Ni-Cr, Co-Cr e do metal Ti Cp. Após o polimento metalográfico e jateamento com Al2O3, foram obtidos três grupos experimentais para cada metal : Grupo polimento (P) - controle; Grupo (J50), jateado com Al2O3 de 250 um. A esses grupos foram aplicados os condicionadores e as resinas opaca e de revestimento estético (Artglass). Decorridos 24 horas de armazenamento em água a 37ºC, cada grupo foi dividido em dois grupos e submetidos aos ensaios mecânicos de cisalhamento (0,5 mm/min.), um antes e outro após 500 ciclos térmicos (60ºC e 4ºC). As superfícies fraturadas foram analisadas e o padrão de falhas determinado. Adicionalmente foram feitas análises de MEV e EDS. Seguem os resultados para cada metal: Liga de Ni-Cr: para os Grupos P e J50, não foram observadas diferenças (p>0,05) nos valores médios de tensão de cisalhamento entre os condicionadores OP e TL e entre MPP e S, sendo maiores as médias dos dois primeiros. Não foram encontradas diferenças (p>0,05) entre as médias de tensão para os condicionadores do Grupo J250. No entanto, esses valores foram superiores aos do Grupo J50. Após a termociclagem, as médias para os condicionadores OP, S e TL não apresentaram aumento significante (p>0,05), enquanto a média para o MPP aumentou (p0,05) nos valores médios de tensão entre os condicionadores OP e TL e entre MPP e S, sendo superiores as médias dos dois primeiros. As médias de tensão para o Grupo J250 foram estatisticamente maiores às do Grupo J50,...The purpose of the study was to evaluated the effect of three adhesive primers (Metal Photo Primer, MPP; Cesead II Opaque Primer, OP; Targis Link, TL) and a bonding system (Siloc, S) on the shear bond strength between a prosthetic composite material (Artglass) to Ni-Cr alloy (Wiron 99), Co-Cr alloy (Wironit), and CP Ti (Tritan). Disk patterns were cast of the 3 alloys. All the disk surfaces were abraded with No. 80, 320, and 600 SiC paper, respectively and three different surface treatment were applied: No. 600 SiC polishing, P; 50 mm Al2O3 sandblasting, S50; 250 mm Al2O3 sandblasting, S250. The composites (Artglass opaque and dentin) were applied using a cylindrical stainless steel split according to manufacturer's instructions then light polymerized. Specimens without primer and bonding system were also prepared as control. The specimens were stored in water a 37oC for 24 h and then shear bond strengths were determined both before and after immersed alternately in water baths at 4oC and 60oC for 15 seconds each for up to 500 thermal cycles before shear mode testing at a crosshead speed of 0.5 mm/min. Data were statistically analyzed using 3-way ANOVA and 1-way ANOVA, followed by Tukey multiple range intervals calculated at the 0.05 significance level. Fractured interfaces were analyzed by use of light microscopy and SEM. Results: Ni-Cr alloy: The bond strength of the P-OP/J50-OP group and P-TL/J50- TL group were statistically comparable (p>0,05) and exhibited greater strength than the P-MPP/J50-MPP group and P-S/J50-S (p0,05), and these group showed the greater strength than the J50 group (p0,05) were found among the three primers (OP, S, TL) and the bond strength of MPP increased...(Complete abstract, click electronic access below)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Adhesive bonding of resin composite to various titanium surfaces using different metal conditioners and a surface modification system

Objective: This study evaluated the effect of three metal conditioners on the shear bond strength (SBS) of a prosthetic composite material to cpTi grade I having three surface treatments. Material and Methods: One hundred sixty eight rivet-shaped specimens (8.0x2.0 mm) were cast and subjected to polishing (P) or sandblasting with either 50 mm (50SB) or 250 mm (250SB) Al2O3. The metal conditioners Metal Photo Primer (MPP), Cesead II Opaque Primer (OP), Targis Link (TL), and one surface modification system Siloc (S), were applied to the specimen surfaces, which were covered with four 1-mm thick layers of resin composite. The resin layers were exposed to curing light for 90 s separately. Seven specimens from each experimental group were stored in water at 37ºC for 24 h while the other 7 specimens were subjected to 5,000 thermal cycles consisting of water baths at 4ºC and 60ºC (n=7). All specimens were subjected to SBS test (0.5 mm/min) until failure occurred, and further 28 specimens were analyzed using scanning electron microscope (SEM) and X-ray energy-dispersive spectroscopy (EDS). Data were analyzed by 3-way ANOVA followed by post-hoc Tukey's test (α=0.05). Results: On 50SB surfaces, OP groups showed higher SBS means than MPP (

Adhesive bonding of resin composite to various titanium surfaces using diferente metal conditioners and a surface modification system

Objective: This study evaluated the effect of three metal conditioners on the shear bond strength (SBS) of a prosthetic composite material to cpTi grade I having three surface treatments. Material and Methods: One hundred sixty eight rivet-shaped specimens (8.0x2.0 mm) were cast and subjected to polishing (P) or sandblasting with either 50 mu m (50SB) or 250 mu m (2505B) Al2O3. The metal conditioners Metal Photo Primer (MPP), Cesead II Opaque Primer (OP), Targis Link (TL), and one surface modification system Siloc (S), were applied to the specimen surfaces, which were covered with four 1-mm thick layers of resin composite. The resin layers were exposed to curing light for 90 s separately. Seven specimens from each experimental group were stored in water at 37 degrees C for 24 h while the other 7 specimens were subjected to 5,000 thermal cycles consisting of water baths at 4 degrees C and 60 degrees C (n=7). All specimens were subjected to SBS test (0.5 mm/min) until failure occurred, and further 28 specimens were analyzed using scanning electron microscope (SEM) and X-ray energy-dispersive spectroscopy (EDS). Data were analyzed by 3-way ANOVA followed by post-hoc Tukey's test (alpha=0.05). Results: On 50SB surfaces, OP groups showed higher SBS means than MPP (P<0.05), while no significant difference was found among OP, 5, and TL groups. On 2505B surfaces, OP and TL groups exhibited higher SBS than MPP and S (P<0.05). No significant difference in SBS was found between OP and TL groups nor between MPP and S groups. The use of conditioners on 250SB surfaces resulted in higher SBS means than the use of the same products on 50SB surfaces (P<0.05). Conclusion: Sandblasting associated with the use of metal conditioners improves SBS of resin composites to cpTi.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Effect of potentially chromogenic beverages on shear bond strength of acrylic denture teeth to heat-polymerized denture base resins

Background: Detachment of denture acrylic resin artificial teeth from denture base resin is one of the most common problems presented by denture wearers. Purpose: This study investigated the shear bond strength (SBS) and fracture type of bonding interface of two commercial acrylic teeth (Vipi Dent Plus e Biolux) to two denture base resins (Vipi Cril e Lucitone 550) after immersion in potentially chromogenic beverages (coffee, cola soft drink, and red wine) or control solution (distilled water). Materials and Methods: Maxillary central incisor acrylic teeth were placed at 45° to denture base resin and submitted to short polymerization cycle according to manufacturers. Specimens were divided according to the combination tooth/resin/solution (n = 8) and submitted to bond strength tests in a universal testing machine MTS-810 (0.5 mm/min). Subsequently, fracture area was analyzed by stereomicroscope at a magnification of ×10 and categorized into adhesive, cohesive, or mixed failure. Results: The bond strength of teeth/denture base resins interface was not significantly affected by tested solutions (P > 0.087), except for Biolux teeth immersed in coffee (P < 0.01). In all conditions, the Vipi Dent Plus teeth showed higher bond strength to Lucitone and Vipi Cril resins when compared to Biolux teeth (P < 0.003). All specimens' failure modes were cohesive. Conclusions: The SBS of acrylic teeth to denture base resins was not generally influenced by immersion in the tested staining beverages

Adhesive Bonding of Resin Composite to Various Ni-Cr Alloy Surfaces Using Different Metal Conditioners and a Surface Modification System

Purpose: This study evaluated the effect of three metal conditioners [Metal Photo Primer (R) (MPP), Cesead II Opaque Primer (R) (OP), Targis Link (R) (TL)], and one surface modification system [Siloc (R) (S)] on the shear bond strength (SBS) of a prosthetic composite material to Ni-Cr alloy.Materials and Methods: Rivet-shaped specimens were cast, and three surface treatments were evaluated: Polishing (P); sandblasting with either 50 mu m (50SB) or 250 mu m (250SB) Al(2)O(3). All products were applied to half of the specimens, while the other half remained without the materials. Veneering resin composite (8-mm diameter, 2-mm thick) was applied and light-exposed for 90 seconds in a laboratory light-curing unit. The specimens were stored in water at 37 degrees C for 24 hours, and half were subjected to 500 thermal cycles consisting of water baths at 4 degrees C and 60 degrees C. All specimens were submitted to SBS test (0.5 mm/min) until failure. Failure patterns were determined using optical and scanning electron microscope (SEM) analysis. Data were analyzed by ANOVA and post hoc Tukey's test (preset alpha of 5%).Results: The SBS values of OP and TL groups were higher than those of MPP and S within the 50SB treatment (p 0.05). The SBS values of MPP, OP, and S from the 250SB group were higher than those from 50SB (p < 0.05). No significant difference in SBS was noted among most groups with conditioners after thermocycling. The only exception was observed for MPP, which showed an increase in SBS after thermocycling (p < 0.05). Differences in SBS were noted among the groups with conditioners (p < 0.05), and no significant difference in SBS was noted between TL and OP groups, which showed the highest values among all within the P group. No significant difference was noted between MPP and S. Debonded surfaces showed adhesive failures predominantly located between metal surface and opaque resin.Conclusions: The OP and TL conditioners and surface sandblasting with 250 mu m Al(2)O(3) promoted the highest SBS between resin and the Ni-Cr metal surface.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP