RESUMEN
PURPOSE: This study was conducted to evaluate clinical validity of a zirconia full-coverage crown by comparing zirconia's wear capacity over antagonistic teeth with that of feldspathic dental porcelain. MATERIALS AND METHODS: The subject groups were divided into three groups: the polished feldspathic dental porcelain group (Group 1), the polished zirconia group (Group 2), and the polished zirconia with glazing group (Group 3). Twenty specimens were prepared from each group. Each procedure such as plasticity, condensation, and glazing was conducted according to the manufacturer's manual. A wear test was conducted with 240,000 chewing cycles using a dual-axis chewing simulator. The degree of wear of the antagonistic teeth was calculated by measuring the volume loss using a three-dimensional profiling system and ANSUR 3D software. The statistical significance of the measured degree of wear was tested with a significant level of 5% using one-way ANOVA and the Tukey test. RESULTS: The degrees of wear of the antagonistic teeth were 0.119 +/- 0.059 mm3 in Group 1, 0.078 +/- 0.063 mm3 in Group 3, and 0.031 +/- 0.033 mm3 in Group 2. Statistical significance was found between Group 1 and Groups 2 and between Group 2 and 3, whereas no statistical significance was found between Group 1 and Group 3. CONCLUSION: Despite the limitations of this study on the evaluation of antagonistic teeth wear, the degree of antagonistic tooth wear was less in zirconia than feldspathic dental porcelain, representing that the zirconia may be more beneficial in terms of antagonistic tooth wear.
Asunto(s)
Análisis de Varianza , Cerámica , Coronas , Porcelana Dental , Masticación , Plásticos , Diente , Desgaste de los Dientes , CirconioRESUMEN
The purpose of this study was to describe the differences in three phenomenological research methods used to understand the experience of families of patients with cancer and so provide as guideline to novices first attempting qualitative research. The subjects were 3 family members - spouse, daughter, daughter-in-law -of cancer patients at S-hospital. Unstructured deep interviews were carried out and taped for further analyzed. Interviews were analyzed using three phenomenological methods ; Giorgi's, Colazzi's, and Van Kaam's. The results are as follows: The experience of family the analyzed using Giorgi's method showed different characteristics according to the family members' role. According to Colaizzi's method, they experienced burden, a willingness to care, role conflict, thanks to family and significant others, and ambivalence about treatment. Using Van Kaam's methodology, two categories were identified ; change of family function and burden. Themes in change of family function were positive attitude(9), role conflict(6), negative attitude(5), active attitude(2), and passive attitude(2) ; Themes in burden were emotional burden, physical burden, and economic burden. The result from using Giorgi's method were centered or individual characteristics and these results constituteds situational structured description and a general structured description. From Colaizzi's method the focus was on the common experience of all fo the subjects. In Van Kaam's method, subthemes (13), themes(8), and categories(2) were identified. So researchers should choose the qualitative method according to their research goals and methodological characteristics.