fa Effects of extreme cooling methods on mechanical properties and shear bond strength of bilayered porcelain/3Y-TZP specimens ترمیمی Cosmetic and Restorative Dentistry پژوهشي Research <p> <strong>Objectives </strong></p><p> This study investigated the effect of extreme cooling methods on the flexural strength, reliability and shear bond strength of veneer porcelain for zirconia. </p><p> <strong>Methods</strong> </p><p> Vita VM9 porcelain was sintered on zirconia bar specimens and cooled by one of the following methods: inside a switched-off furnace (slow), at room temperature (normal) or immediately by compressed air (fast). Three-point flexural strength tests (FS) were performed on specimens with porcelain under tension (PT, n=30) and zirconia under tension (ZT, n=30). Shear bond strength tests (SBS, n=15) were performed on cylindrical blocks of porcelain, which were applied on zirconia plates. Data were submitted to one-way ANOVA and Tukey's post hoc tests (p<0.05). Weibull analysis was performed on the PT and ZT configurations. </p><p> <strong>Results</strong></p><p>  One-way ANOVA for the PT configuration was significant, and Tukey's test revealed that fast cooling leads to significantly higher values (p<0.01) than the other cooling methods. One-way ANOVA for the ZT configuration was not significant (p=0.06). Weibull analysis showed that normal cooling had slightly higher reliability for both the PT and ZT configurations. Statistical tests showed that slow cooling decreased the SBS value (p<0.01) and showed less adhesive fracture modes than the other cooling methods.</p><p> <strong> Clinical Significance</strong></p><p>  Slow cooling seems to affect the veneer resistance and adhesion to the zirconia core however, the reliability of fast cooling was slightly lower than that of the other methods. </p><hr><p></p><p> <strong>Source: </strong>Journal of Dentistry</p><p> <a href="http://www.jodjournal.com/article/S0300-5712(13)00023-7/abstract" target="_blank"><font color="#0000ff">Full Text</font></a></p> Dental ceramic, Zirconia, Bilayer ceramic, Cooling, Residual stress 0 0 http://idai.ir/browse.php?a_code=A-10-32-2139&slc_lang=fa&sid=1 Antonio A. Almeida-Júnior 100319475328460010034 100319475328460010034 No UNESP – Univ Estadual Paulista, Faculdade de Odontologia de Araraquara, R. Humaitá, 1680 Sala 415, Centro. Araraquara, SP 14801-903, Brazil Diogo Longhini 100319475328460010035 100319475328460010035 No UNESP – Univ Estadual Paulista, Faculdade de Odontologia de Araraquara, R. Humaitá, 1680 Sala 415, Centro. Araraquara, SP 14801-903, Brazil Natália B. Domingues 100319475328460010036 100319475328460010036 No UNESP – Univ Estadual Paulista, Faculdade de Odontologia de Araraquara, R. Humaitá, 1680 Sala 415, Centro. Araraquara, SP 14801-903, Brazil Claudinei Santos 100319475328460010037 100319475328460010037 No Universidade do Estado do Rio de Janeiro – Faculdade de Tecnologia de Resende, Etr Resende-Riachuelo, S/N, Morada da Colina, Resende, RJ 27523-000, Brazil Gelson L. Adabo 100319475328460010038 100319475328460010038 Yes UNESP – Univ Estadual Paulista, Faculdade de Odontologia de Araraquara, R. Humaitá, 1680 Sala 415, Centro. Araraquara, SP 14801-903, Brazil