ABSTRACT
This work aims to evaluate the effects of feldspar substitution by basalt on porcelain tile composition with respect to its porosity, flexural strength, and pyroplastic deformation. Three ceramic formulations with different amounts of feldspar substituted with basalt, 50% (C1), 75% (C2), and 100% (C3), were evaluated at three different temperatures, 1200, 1220, and 1240 °C. Specifically, the effect of replacing feldspar with basalt on the pyroplastic deformation of ceramic bodies was analysed using optical fleximetry. The porosity of C1 at 1200 °C was 19.3 ± 2.9%, while that of composition C3 was 22.2 ± 0.7% at 1240 °C. The flexural strength was strongly influenced by the temperature. For C1 at 1200 and 1240 °C, flexural strengths of 11.1 ± 0.6 and 22.2 ± 1.9 MPa, respectively, were obtained. Regarding fleximetry, thermal deformation decreased with an increase in the amount of feldspar substituted with basalt. It was observed that C2 and C3 deformed less at high temperatures than the other combinations of compositions and temperature, probably owing to the lower amount of residual glass phase present during cooling. Compositions with higher substitution amounts of basalt (i.e., C2 and C3) exhibited more stable thermal behaviour than C0.
ABSTRACT
OBJETIVO: Determinar a confiabilidade intra e interexaminadores e correlacionar os valores de amplitudes de movimentos (ADM) cervical obtidas por fleximetria e goniometria em crianças. MÉTODOS: Participaram deste estudo 106 crianças saudáveis, 49 meninos (8,91±2,09 anos) e 57 meninas (9,14±1,46 anos), com idades entre seis e 14 anos, assintomáticas para disfunção cervical. Dois examinadores previamente treinados e dois auxiliares avaliaram a ADM cervical. Os examinadores coletaram as medidas por fleximetria e goniometria (confiabilidade interexaminadores) e repetiram as avaliações, após uma semana (confiabilidade intra-examinador). Todas as medidas foram registradas três vezes por cada examinador e o valor médio foi considerado para análise estatística. O coeficiente de correlação intraclasse (ICC 2,1 e 2,2) foi utilizado para verificação das confiabilidades e o coeficiente de correlação de Pearson (p<0,05) foi utilizado para verificação da correlação entre as medidas obtidas por ambas as técnicas. RESULTADOS: Foram observadas confiabilidades intra-examinador moderado e excelente para a fleximetria e moderada para a goniometria. As confiabilidades interexaminadores foram moderada e excelente para a fleximetria e pobre e moderada para a goniometria. Foi verificada correlação significativa e pobre entre todas as medidas de ADM cervical obtida pelas técnicas estudadas, exceto para o movimento de rotação à esquerda. CONCLUSÕES: A correlação pobre entre as mensurações de ADM cervical obtidas por fleximetria e goniometria demonstram que as técnicas não apresentam medidas intercambiáveis e, como a fleximetria apresentou maiores níveis de confiabilidade para avaliação da ADM cervical em crianças, seu uso é recomendado em relação à goniometria.
OBJECTIVE: To determine the intra and interrater reliability of fleximetry and goniometry in children and correlate the cervical spine range of motion (ROM) values obtained from these methods. METHODS: One hundred six children participated in this study: 49 males (8.91±2.09 years) and 57 females (9.14±1.46 years). Their ages ranged from six to 14 years and symptom-free to cervical dysfunction. Two previously trained raters and two assistants assessed neck ROM. The measurements were made using fleximetry and goniometry (interrater reliability) and repeated them one week later (intrarater reliability). All measurements were made three times by each rater and the mean value was used for statistical analysis. Intraclass correlation coefficients (ICC 2.1 and 2.2) were used to investigate reliability and Pearson's correlation coefficient (p<0.05) was used to investigate the correlation between measurements obtained from the two techniques. RESULTS: Moderate and excellent levels for intrarater reliability were observed for fleximetry and moderate reliability for goniometry. The interrater reliability was moderate and excellent for fleximetry and poor and moderate for goniometry. Significantly poor correlation was found among all neck ROM measurements obtained using both techniques, except for rotation to the left. CONCLUSIONS: The poor correlation between neck ROM measurements obtained from fleximetry and goniometry demonstrated that these techniques do not present interchangeable measurements. Since fleximetry presented higher reliability levels for assessments of neck ROM among children, the use of fleximetry rather than goniometry is recommended.