Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Oper Dent ; 49(1): 34-42, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38180470

RESUMO

This non-controlled clinical study evaluated the masking effect of an infiltrant resin on mild molar incisor hypomineralization (MIH) lesions. Thirty MIH-affected anterior teeth with creamy/ white opacities from 12 children aged 6-15 years received the application of an infiltrant resin (Icon- DMG). Standard photographs were taken before (T1), immediately after (T2), and 1 week after (T3) resin infiltration. Two calibrated examiners qualitatively analyzed the color match using the Fédération Dentaire Internationale (FDI) scale. The binomial distribution test analyzed the scores of the color match at T1 with T2 and T3, and McNemar's test analyzed the scores of the color match between T2 and T3 (α=0.05). There was a significant increase in color match between T1 and T2 (p=0.0005), between T1 and T3 (p=0.0005), and between T2 and T3 (p=0.0019). It was concluded that infiltrant resin was effective in improving the esthetic appearance of creamy/white opacities on MIH-affected anterior teeth.


Assuntos
Hipomineralização Molar , Resinas Sintéticas , Criança , Humanos
2.
Oper Dent ; 47(4): 449-460, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35917252

RESUMO

The aim of this laboratory study was to evaluate the pull-out force of a prefabricated fiberglass post (PP), relined fiberglass post (RP), or milled fiberglass post (MP) luted with Multilink N (MN), RelyX Unicem 2 (RXU2) or RelyX Ultimate (RU) to enlarged root canals. The thickness of the resin cements and the presence of voids in the resin cement film were observed. The root canals of 90 bovine incisors were enlarged, endodontically treated, and randomly divided into 9 groups (n=10) according to the post type and resin cement. The specimens were scanned using micro-CT to analyze the thickness of the resin cement and the presence of voids. The specimens were submitted to mechanical cyclic loading (500,000 cycles at 50 N load) and subjected to pull-out force testing. Two-way ANOVA and Tukey's test analyzed the pull-out force and resin cement thickness data. Kruskal-Wallis and Bonferroni tests analyzed the void scores. The interaction between factors (post × resin cement) was significant (p=0.0001) for the pull-out force. Higher pull-out forces were obtained for RP and MP compared to PP. The post factor was significant (p=0.0001) for resin cement thickness, which was higher for PP (1054 µm), followed by MP (301 µm) and RP (194 µm). More void formation occurred for PP, being less for RP, differing significantly among the posts. Post customization (RP and MP) decreased resin cement thickness and void formation, favoring a higher pull-out force. Resin cements requiring an adhesive application (MN and RU) favored higher pull-out force than self-adhesive resin cement (RXU2).


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Animais , Bovinos , Cavidade Pulpar , Vidro , Teste de Materiais , Cimentos de Resina/uso terapêutico
3.
Oper Dent ; 45(2): 209-218, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31774724

RESUMO

The aim was to evaluate, in vitro, quantitatively and qualitatively, the effect of pH cycling and simulated toothbrushing on surface roughness (Ra) and bacterial adhesion (Cn) of bulk-fill composite resins. Thirty specimens of each composite resin, 5 mm wide and 4 mm high, were obtained: group 1 (control): Filtek Z250 (Z250); group 2: Filtek Bulk-Fill (FTK); group 3: Tetric N-Ceram Bulk-Fill (TTC); and group 4: Aura Bulk-Fill (AUR). After 24 hours, the specimens were polished and then alternated with demineralization/remineralization solutions for 15 cycles of 24 hours each at 37°C. Then the specimens were submitted to simulated toothbrushing. The Ra and Cn measurements were quantitatively analyzed in three stages: after polishing (Ra0 and Cn0), after pH cycling (Ra1 and Cn1), and after simulated toothbrushing (Ra2 and Cn2). The Ra values were submitted to two-way analysis of variance, followed by the Tukey test (α=0.05). The Kruskal-Wallis test, followed by multiple comparisons, was applied for Cn analysis. Surface topography and bacterial adhesion were observed by scanning electron microscopy (SEM). Z250, FTK, and TTC showed no significant change in Ra regardless of the treatment performed; AUR obtained increased Ra at Ra2 (p<0.05). FTK differed from the others at Cn0 and Cn1 (p<0.05). At Cn2, there was no difference among the composite resins. SEM images showed the exposure of fillers and microcavities at Ra1 and Ra2. There was greater bacterial adhesion at Cn1 for Z250 and FTK. It was concluded that the pH cycling caused surface degradation of all composite resins, which was potentiated by simulated toothbrushing. However, only AUR presented an increased Ra. Bacterial adhesion occurred on all composite resins after pH cycling; however, after simulated toothbrushing, adhesion of dispersed bacteria was similar for all the composite resin groups.


Assuntos
Aderência Bacteriana , Escovação Dentária , Resinas Compostas , Polimento Dentário , Concentração de Íons de Hidrogênio , Teste de Materiais , Propriedades de Superfície
4.
Oper Dent ; 43(5): 539-548, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29513638

RESUMO

The aim was to evaluate, in vitro, the influence of different computer-aided design/computer-aided manufacturing (CAD/CAM) materials (IPS e.max CAD, Vita Enamic, and Lava Ultimate) and thicknesses (0.6 mm and 1.5 mm) on the fracture resistance of occlusal veneers. Sixty human third molars were prepared to simulate advanced erosion of the occlusal surface, and the teeth were randomly divided into six experimental groups (n=10) according to the material and thickness used to build the veneers. Ten sound teeth formed the control group. The veneers were adhesively luted and submitted to mechanical cyclic loading (1 million cycles at 200-N load). The fracture resistance test was performed in a universal testing machine. The failures were classified as "reparable" and "irreparable." According to two-way analysis of variance and the Tukey test, the interaction (material × thickness) was significant ( p=0.013). The highest fracture resistance was obtained for IPS e.max CAD at a 1.5-mm thickness (4995 N) and was significantly higher compared to the other experimental groups ( p<0.05). The lowest fracture resistance was obtained for Vita Enamic at 0.6 mm (2973 N), although this resistance was not significantly different from those for IPS e.max CAD at 0.6 mm (3067 N), Lava Ultimate at 0.6 mm (3384 N), Vita Enamic at 1.5 mm (3540 N), and Lava Ultimate at 1.5 mm (3584 N) ( p>0.05). The experimental groups did not differ significantly from the sound teeth (3991 N) ( p>0.05). The failures were predominantly repairable. The occlusal veneers of IPS e.max CAD, Vita Enamic, and Lava Ultimate, with thicknesses of 0.6 mm and 1.5 mm, obtained fracture resistances similar to those associated with sound teeth.


Assuntos
Cerâmica/uso terapêutico , Desenho Assistido por Computador , Porcelana Dentária/uso terapêutico , Planejamento de Prótese Dentária/métodos , Facetas Dentárias , Falha de Restauração Dentária , Análise do Estresse Dentário , Humanos , Técnicas In Vitro , Dente Molar/cirurgia
5.
Arq. bras. med. vet. zootec ; 65(6): 1609-1615, Dec. 2013. tab
Artigo em Português | LILACS | ID: lil-696838

RESUMO

O objetivo deste estudo foi buscar associação entre a taxa de prenhez após inseminação e natalidade com marcadores moleculares ligados aos genes do receptor para IGF-1, LHβ, Leptina e receptores do FSH e LH. Utilizaram-se 249 vacas adultas Aberdeen Angus, das quais 199 foram submetidas a protocolos distintos para a IATF, seguida pelo repasse com touros, e 50 vacas formaram o grupo controle representado pelo acasalamento com touros. Foram avaliados o escore de condição corporal (ECC) e o escore de condição ovariana (ECO) ao início da estação reprodutiva. O ECC influenciou a taxa de natalidade, respectivamente de 55,6%, 75,8% e 82,4% (P<0,05) para os animais com ECC menor que 2,5, entre 2,5 a 2,9, e maior ou igual a 3,0, por ocasião da estação reprodutiva. Os marcadores relacionados ao gene do receptor para o IGF-1 (AFZ-1 e HEL5) mostraram associação com a taxa de natalidade. Vacas homozigóticas para o marcador AFZ-1 apresentaram 84,4% de natalidade em comparação às heterozigóticas, com 71,5% (P<0,05). A presença do alelo*161 para o marcador HEL5 foi negativa sobre a natalidade, respectivamente de 33,3% e 76,5% para vacas com e sem esse alelo (P<0,05). Esses resultados demonstram uma importante associação entre os marcadores envolvidos com o receptor para o IGF-1 e desempenho reprodutivo de vacas Angus.


The association between the reproductive performance, expressed by pregnancy rate at fixed timed artificial insemination and birth rate in the subsequent season in beef cows, and molecular markers linked to genes for IGF-1 receptor, LHβ, leptin, and FSH and LH receptors were evaluated. Data from 249 Aberdeen Angus adult cows were used in this study. One hundred and ninety-nine cows were subjected to four different protocols for FTAI, followed by clean-up bulls and 50 cows formed the control group, matted only with bulls for 90 days during the mating season. Body condition score (BCS) and ovarian condition score (OCE) were evaluated at the beginning of the breeding season. The birth rate in the following year was 75.5%, with no treatments influence. The BCS has influenced the birth rate, respectively 55.6%, 75.8% and 82.4% (P<0.05) for animals with BCS less than 2.5; 2.5 to 2.9; and greater than or equal to 3.0, at the beginning of the breeding season. The markers related to IGF-1 receptor gene (AFZ-1 and HEL5) were associated with the birth rate in beef cows. Cows homozygous for AFZ-1 marker showed 84.4% of birth rate, while heterozygous cows showed 71.5% (P <0.05). The presence of allele *161 to the HEL5 marker was negative on birth rate. Cows with this allele had only 33.3% of birth rate, while cows without this allele had 76.5% of birth rate (P <0.05). These results demonstrate a significant association between the markers involved with the IGF-1 receptor and reproductive performance of Aberdeen Angus beef cows.


Assuntos
Animais , Bovinos , Coeficiente de Natalidade , Fator de Crescimento Insulin-Like I/análise , Fertilidade/fisiologia , Bovinos
6.
Arq. bras. med. vet. zootec ; 64(2): 295-304, abr. 2012. tab
Artigo em Português | LILACS | ID: lil-622480

RESUMO

Compararam-se efeitos de diferentes protocolos para a IATF com o acasalamento natural (Controle) sobre o desempenho reprodutivo de 249 vacas Aberdeen Angus, distribuídas em cinco grupos: Controle (n=50); Crestar 2º uso (n=64); OvSynch (n=65); Primer 1ºuso (n=35) e Primer 2º uso (n=35). A IATF dos animais dos grupos Crestar 2º uso, OvSynch, e Primer 1º uso foi realizada 27 dias após o início da estação do grupo controle e a IATF do grupo Primer 2º uso ocorreu 38 dias após o início da estação do grupo-controle. A partir de sete dias após a IATF, os animais foram submetidos ao repasse por touros até o término da estação de acasalamento, que foi de 91 dias para o grupo-controle, 64 dias para os grupos Crestar 2º uso, OvSynch e Primer 1º uso e de 53 dias para o grupo Primer 2º uso. A taxa de gestação ao final da estação de acasalamento não se diferenciou entre os grupos (P>0,05), sendo de 85,9%; 83,1%; 82,9%; 88,6% e 80,0%, respectivamente, para Crestar 2º uso; OvSynch; Primer 1º uso; Primer 2º uso e Controle. A taxa de parição resultante da IATF foi de 23,4%; 29,2%; 48,6% e 62,9% para os grupos Crestar 2º uso, OvSynch, Primer 1º uso, Primer 2º uso, respectivamente, com diferença significativa (P<0,05) entre Crestar e Primer 1º e 2º uso. OvSynch não se diferenciou de Crestar e Primer 1º uso. Primer 1º uso não se diferenciou de Primer 2º uso. A perda gestacional, do diagnóstico de gestação ao nascimento, foi de 10,5%. O intervalo de partos estimado (IEP) não apresentou diferenças, com média de 478 dias. O escore de condição corporal (ECC) de fêmeas gestantes ao final da estação reprodutiva foi diferente do de fêmeas não gestantes (controle), mas não dos demais grupos, possivelmente pela influência do tratamento em induzir a ciclicidade dos animais com ECC inferior. O atraso da realização da IATF após 27 ou 38 dias do início da estação de acasalamento não afetou a taxa de gestação final e o IEP dos animais, quando comparado ao acasalamento por touros.


The effects of different FTAI protocols were compared to the natural mating of bulls on the reproductive performance of 249 Aberdeen Angus cows. Five groups were formed: Control (n=50); Crestar 2nd use (n=64); OvSynch (n=65); Primer 1st use (n=35) and Primer 2nd use (n=35). The FTAI of the animals in the Crestar 2nd use, OvSynch and Primer 1st use groups was accomplished 27 days after the beginning of the mating season for the control group and the FTAI in the Primer 2nd use group happened 38 days after the beginning of the mating season of the control group. From seven days after the FTAI cows were exposed to bulls until the end of the mating season. The mating season was of 91 days for the control group, 64 days for the Crestar 2nd use, OvSynch and Primer 1st use groups and 53 days for the Primer 2nd use group. The pregnancy rate at the end of the mating season didn't differ among the groups (P>0.05), being 85.9; 83.1; 82.9; 88.6 and 80.0% respectively, for Crestar 2nd use, OvSynch, Primer 1st use, Primer 2nd use and Control. The birth rate resulting from FTAI was 23.4; 29.2; 48.6 and 62.9% for the Crestar 2nd use, OvSynch, Primer 1st use, Primer 2nd use groups, with significant difference (P<0.05) among Crestar and Primer 1st and 2nd use. OvSynch didn't differ in Crestar and Primer 1st use. Primer 1st use didn't differ from Primer 2nd use. The average reproductive losses between the gestation diagnosis and the birth were10.5%. The estimated calving interval (CI) didn't present differences among the animal groups, with an average of 478 days. The body condition score (BCS) of pregnant cows at the end of the reproductive station differed from BCS of empty cows in the control group, but it didn't differ in the other groups, possibly due to the hormonal treatment influence in inducing the oestrus and ovulation in animals with lower BCS. The delay of the accomplishment of FTAI after 27 or 38 days of the beginning of the mating season didn't affect the final pregnancy rate and CI of the cows, when compared to natural mating.

7.
Arq. bras. med. vet. zootec ; 60(2): 414-418, abr. 2008. tab
Artigo em Português | LILACS | ID: lil-484669

RESUMO

Avaliou-se o desempenho reprodutivo de novilhas de corte acasaladas aos 14 meses (14M), aos 24 meses (24 M) e de vacas multíparas (V), totalizando 4.012 animais. As perdas reprodutivas (PR) foram de 19,3 por cento, 11,6 por cento e 7,6 por cento para 14M, 24M e V, respectivamente, sendo que 14M diferiu de V (P<0,01). A ocorrência de distocia foi de 20,7 por cento, 5,1 por cento e 0,8 por cento para as categorias 14M, 24M e V, respectivamente, sendo que 14M diferiu de V (P<0,01). Ocorreu maior mortalidade causada por distocia entre os animais do grupo 14M que entre os do grupo V (P<0,01), 7,4 por cento e 0,4 por cento, respectivamente. A reconcepção foi maior nos animais de 14M (85,3 por cento) e V (81,1 por cento), comparada à dos de 24M (70,7 por cento) (P<0,01). A categoria que teve maior concentração de parição no primeiro período, 52,3 por cento (até 19/09), foi a de 24M (P<0,01). Animais acasalados mais jovens tendem a apresentar maiores perdas reprodutivas e ocorrências de distocia.


Reproductive performances of beef heifers mated at 14 months of age (14M), at 24 months of age (24M) and pluriparous cows (C), based on data from 4.012 animals were evaluated. The reproductive disorders were 19.3 percent, 11.6 percent and 7.6 percent, respectively, at 14M, 24M and for C; 14M was different from C (P<0.01). The occurrence of dystocia was 20.7 percent, 5.1 percent and 0.8 percent for the 14M, 24M and C, respectively. The 14M group was different from C (P<0.01). The mortality caused by dystocia was higher for 14M group 7.4 percent than for the C group 0.4 percent (P<0.01), respectively. The reconception rate was higher for the 14M (85.3 percent) and V (81.1 percent) than for the 24M group (70.7 percent) (P<0.01). The category which concentrated the parturition in the first period (until 09/19) (52.3 percent) was the 24M. Animals mated earlier tended to show high reproductive disorders and incidence of dystocia.


Assuntos
Animais , Ligação do Par , Bovinos , Distocia , Mortalidade , Reprodução
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...