Effect of endodontic sealers on push-out bond strength of CAD-CAM or prefabricated fiber glass posts.

This study aimed to evaluate the effect of endodontic sealer (ES) on bond strength (BS) of prefabricated or milled-CAD-CAM (computer-aided design and computer-aided manufacturing) glass-fiber-posts (GFP). Canals of 90 single-rooted teeth were prepared for filling by the single-cone technique with gutta-percha and one of the following ES: AH Plus (epoxy resin), Endofill (zinc-oxide and eugenol), and Bio-C Sealer (calcium-silicate). After post-space preparation, tooth-specimens were equally divided in half according to type of GFP to be used. In the half to receive milled-CAD-CAM posts, tooth specimens were molded with acrylic resin to obtain replicas. These were scanned to enable the laboratory to produce the milled-CAD-CAM GFPs (Fiber CAD Lab, Angelus) by the subtractive technique. The other half of samples received prefabricated GFPs (Exacto, Angelus) (n=15). The GFPs were cemented with dual-cure resin cement (Panavia F2.0, Kuraray). Each root was sectioned into two slices per root region (cervical, middle, apical) that were subjected to the push-out BS test, in a universal testing machine. Failure mode (FM) was classified by scores. The BS data were submitted to generalized linear model analyses, while FM was analyzed using the chi-square test (a=0.05). BS showed no significant difference among the three ES (p > 0.05). BS was significantly higher for prefabricated (mean 10.84 MPa) versus milled-CAD-CAM GFPs (mean 6.94 MPa) (p <0.0001), irrespective of ES. The majority showed mixed failures. It could be concluded that type of ES did not affect BS of GFPs to dentin, and prefabricated-GFPs had higher bond-strength than customized-milled-CAD-CAM GFPs.

Effect of endodontic sealers on push-out bond strength of CAD-CAM or prefabricated fiber glass posts

Abstract This study aimed to evaluate the effect of endodontic sealer (ES) on bond strength (BS) of prefabricated or milled-CAD-CAM (computer-aided design and computer-aided manufacturing) glass-fiber-posts (GFP). Canals of 90 single-rooted teeth were prepared for filling by the single-cone technique with gutta-percha and one of the following ES: AH Plus (epoxy resin), Endofill (zinc-oxide and eugenol), and Bio-C Sealer (calcium-silicate). After post-space preparation, tooth-specimens were equally divided in half according to type of GFP to be used. In the half to receive milled-CAD-CAM posts, tooth specimens were molded with acrylic resin to obtain replicas. These were scanned to enable the laboratory to produce the milled-CAD-CAM GFPs (Fiber CAD Lab, Angelus) by the subtractive technique. The other half of samples received prefabricated GFPs (Exacto, Angelus) (n=15). The GFPs were cemented with dual-cure resin cement (Panavia F2.0, Kuraray). Each root was sectioned into two slices per root region (cervical, middle, apical) that were subjected to the push-out BS test, in a universal testing machine. Failure mode (FM) was classified by scores. The BS data were submitted to generalized linear model analyses, while FM was analyzed using the chi-square test (a=0.05). BS showed no significant difference among the three ES (p > 0.05). BS was significantly higher for prefabricated (mean 10.84 MPa) versus milled-CAD-CAM GFPs (mean 6.94 MPa) (p <0.0001), irrespective of ES. The majority showed mixed failures. It could be concluded that type of ES did not affect BS of GFPs to dentin, and prefabricated-GFPs had higher bond-strength than customized-milled-CAD-CAM GFPs.

Degradabilidade ruminal da cana-de-açúcar integral tratada com diferentes níveis de hidróxido de sódio / Degradability of integral sugar cane treated with different sodium hidroxide levels

O experimento foi realizado utilizando-se quatro bovinos fistulados no rúmen. Durante o experimento, osanimais receberam uma dieta à base de silagem de milho e cana-de-açúcar picada e tratada com 2% deNaOH. Foram avaliados quatro tratamentos à base de cana-de-açúcar com diferentes níveis de NaOH (0,2, 4 e 6%) incubados no rúmen usando-se sacos de náilon. Determinou-se o desaparecimento da matériaseca (MS), matéria orgânica (MO), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA),celulose (CEL) e hemicelulose (HEM) em 0; 6; 12; 24; 48; 72; 96 e 144 horas de incubações no rúmen. Asdegradabilidades potencial (DP) e efetiva (DE) foram determinadas segundo o modelo proposto porOrskov & McDonald (1979) a uma taxa de passagem de 5%/h. Dentro dos tempos de incubação, houvemaior desaparecimento de MS, MO, FDN, FDA, CEL e HEM. para o tratamento com 6% de NaOH.Observou-se maior (P<0,05) DP e DE, respectivamente, para MS (62,01% e 49,39%), MO (62,98% e49,10%), FDN (57,61% e 34,75%), FDA (55,67% e 35,25%), CEL (64,89% e 36,73%) e HEM (61,44% e35,72%), da cana-de-açúcar tratada com 6% de NaOH. Pode-se concluir que o tratamento químico dacana-de-açúcar com 6% de NaOH promoveu maior degradabilidade potencial e efetiva da MS, MO e dafração fibrosa. Os valores de DP e DE da fração fibrosa da cana de açúcar tratada com 6% de NaOH,justificam a utilização deste tratamento nas condições em que estas foram utilizadas.

The experiment was carried out being used four bovine cannulated at rumen. Corn silage and chopped sugar cane, treated with 2% NaOH were furnished to the animals during the experiment. Four treatments consisting of sugar cane treated with 0, 2, 4 and 6% NaOH were evaluated by ruminal incubation usingnylon bags. Dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose (CELL) and hemicellulose (HEM) disappearance were evaluated in 0, 6, 12, 24, 48, 72, 96 and 144 hours of ruminal incubation. Potencial degradability (PD) and effective degradability (ED) were determinated using the model suggested by Orskov & Mc Donald (1979), accepting a passage rate of potassium permanganate; conditioned fruits, in groups of 5, in carton boxes with cover, covered internally or no with low density polyethylene film addictived with potassium permanganate. The fruits were stored under storage room at 24,4 ¨¬C, 70 % RH. The evaluated variables were: loss of fresh mass, appearance, firmness of the pulp, soluble solids, titratable acidity and ascorbic acid. It were verified that the best treatments of modified atmosphere were individual packaging of the mango fruits in plastictrays, covered with plastic film of polivinila chloride (PVC) of 14 ¥ìm, without and with sachet of potassiumpermanganate. The potassium permanganate, in the form used in this study (sachet and impregnated inplastic film), did not interfere in the results obtained for the conservation of the fruits.

Consumo médio e digestibilidade do feno de capim Coast cross (Cynodon dactylon (L. ) pers. ) e feijão guandu (Cajanus cajan (L. )Millsp) em carneiros submetidos a dois regimes alimentares / Coast cross (Cynodon dactylon (L. ) pers. ) hay and pigeon pea (Cajanus cajan (L. ) millsp) digestibility and nutrients average intake by sheep under two feeding systems

O experimento foi realizado com os objetivos de determinar o consumo médio diário (CMD), o coeficientede digestibilidade aparente (CDA) dos nutrientes do feno de capim Coast cross e feijão guandu e avaliaro balanço de nitrogênio (BN) em ovinos. Foram utilizados dez ovinos machos, castrados, com pesomédio de 27,50 kg, alojados em gaiolas para metabolismo, em delineamento inteiramente casualizado comdois tratamentos (T1 = 80% de feno de Coast cross + 20% de guandu e T2 = 60% de feno de Coast cross+ 40% de guandu) e cinco repetições por tratamento. Os tratamentos foram avaliados sob dois regimesalimentares (consumo voluntário e restrito). Os animais recebendo ração do T2 apresentaram maior CMD(g/kg PV0,75) (P<0,05) de matéria seca (MS), proteína bruta (PB), fibra bruta (FB), matéria orgânica (MO)e extrato não nitrogenado (ENN), do que aqueles animais recebendo ração do T1. O CDA da FB da raçãoT2 foi maior (P<0,05) do que o da ração T1. O BN dos animais que receberam 40% de guandu (13,15g N/dia) foi superior aos daqueles que receberam 20% desta leguminosa (10,29g N/dia). Conclui-se que ofeijão guandu pode ser utilizado como fonte protéica na alimentação de ruminantes, possibilitando CDAda MS próximo de 52% para animais em regime de consumo voluntário, e 81% para animais em regime deconsumo restrito. O aumento na porcentagem de feijão guandu nas dietas de ovinos alimentados comfeno de Coast-cross pode resultar em melhoria no CDA da FB da dieta, bem como no balanço denitrogênio dos animais.

This experiment was carried out with the objectives of determining the daily average intake (DAI), apparent digestibility coefficient (ADC) of coast cross hay and pigeon pea nutrients and to evaluate the nitrogen balance in sheep. Ten wethers with average weight of 27.50 kg, alloted to suitable cages, were used. A completely randomized design with two treatments (T1= 80% coast cross hay + 20% pigeon pea and T2= 60% coast cross hay + 40% pigeon pea) and five replicates, was used. The treatments were evaluated under two feeding systems (voluntary and restrict). Animals receiving ration of T2 presented higher DAI (g/kg PV 0.75) (P<0.05) of dry matter (DM), crude protein (CB), crude fiber (CF), organic matter (OM) and nitrogen free extract (NFE), than animals receiving ration of T1. ADC of CF of the T2 were higher (P<0.05) than the ration T1. The nitrogen balance (BN) of animals that received 40% of pigeon pea (13.15g N/dia) was superior to the those receiving 20% of this leguminous (10.29g N/dia). It can be concluded that the pigeon pea can be used as protein source in the ruminant feeding, making possible ADC for DM close to 52% for animals in voluntary intake and 81% for animals in restricted intake. The increase in the percentage of pigeon pea in the sheep diets fed with Coast-cross hay can result in improvement of diet CF digestibility, as well as, in animals nitrogen balance.

Degrabilidade ruminal dos fenos de aveia (Avena sativum L.) Coast cross (Cynodon dactilon L.), e grama Esmeralda (Joysia japonica) petelizado ou não. / Ruminal degradability of oat (Avena sativum L. ), Coast cross (Cynodon dactilon L. ) and Esmeralda grass (Joysia japonica) hay pellet or not

O objetivo deste trabalho foi avaliar a degradabilidade ruminal da matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA) do feno de aveia (FA), feno de coast cross (FCC), feno de grama Esmeralda peletizado (FEP) e feno de grama Esmeralda (FE). Foi utilizada a técnica in situ com quatro bovinos machos, castrados, fistulados no rúmen, distribuídos em um delineamento experimental em quadrado latino 4x4. O material foi incubado no rúmen nos tempos de 0, 6, 24, 48, 72 e 144 horas. Não houve diferença entre os fenos na taxa de degradação (c, h) para a PB, FDN e FDA. Para a MS, o FA e FEP apresentaram maior taxa de degradação. Houve diferença na degradabilidade efetiva (DE) da MS dos fenos sendo os valores observados: FA, 48, 74; FEP, 42, 44; FE, 35, 13; FCC, 30, 24. Conclui-se que o feno de aveia obteve maiores valores para a fração solúvel e maior degradabilidade efetiva para todos os nutrientes avaliados e a peletização da grama Esmeralda promoveu maior DE e MS e da fibra, sem alterar a DE da PB.

The objective of this work was to evaluate the ruminal degradability of dry matter (DM), crude protein(CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of the oat hay (OH), Coast cross hay(CCH), pellet Esmeralda grass hay (PEH) and Esmeralda grass hay (EH). The in situ technique was used,with four bovines, castrated, rumen fistulated, distributed in an Latin square 4x4 experimental design.The material was incubated in the rumen in the times 0, 6, 24, 48, 72 and 144 hours. There was no difference between hays on the degradation rate (c, %/h) for the CP, NDF and ADF. For the DM, the OHand PEH presented higher degradation rate. There was difference on the effective degradability (ED, %)of the hays, and the observed values were: OH, 48.74%; PEH, 42.44%; EH, 35.13%; CCH, 30.24%. It canbe concluded that oat hay presented the highest values for the soluble fraction and for the ED of allnutrients evaluated. The pellet process of the Esmeralda grass resulted in higher ED of the DM and ofthe fiber, with no alteration on the CP ED