Comparison of casting precision of two kinds of commercially available gypsum-bonded investment with different setting and thermal expansion characteristics / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate expansion characteristics of two kinds of commercial investment (Cristo balite Micro II and Cristo Quick), and their effects on cast accuracy of a dental Ag-Pd casting alloy.</p><p><b>METHODS</b>Two kinds of investment were mixed at the ratio of 1:3. The setting and thermal expansion curves of the investment were recorded according to the requirements of ISO7490 and expansion rate calculated, respectively. Plate-like wax-patterns with pre-marked points were invested in casting rings (lined with ceramic fiber liners with thickness of 0.45 mm). Castwell M.C dental alloy were melted with gas flame and cast with a centrifugal casting machine. The differences between the castings and the wax patterns at corresponding points were calculated to represent the dimensional changes of the investment.</p><p><b>RESULTS</b>The setting, thermal and total expansion rates were 0.68, 1.18, 1.86 for Cristo balite Micro II, and 0.94, 1.03, 1.97 for Cristo Quick. The setting and thermal expansion rates were statistically significant between two kinds of investment (P < 0.05), while not for the total expansion rates (P > 0.05). Effect of different investment on the precision of castings was not statistically significant (P > 0.05).</p><p><b>CONCLUSION</b>Within the scope of this study, gypsum-bonded investment with similar total expansion rates but different expansion characteristics has no effect on the casting precision of Ag-Pd dental alloys.</p>

Effects of immunotherapy with infantile recurrent respiratory tract infection by Chinese materia medica / 中国中药杂志

<p><b>OBJECTIVE</b>To explore the effect of Chinese materia medica on immune intervention of infantile recurrent respiratory tract infection.</p><p><b>METHOD</b>Thirty-one children of recurrent respiratory tract infection were randomly divided into two groups: therapy group was treated with oral Chinese materia medica (b. i. d), control group was only treated with oral carboxymethyl liquor (< 4 years, 3 mL; 4-7 years, 5 mL; > 7 years, 7 mL, t. i. d). The change of IL-12,TNF-alpha, IL-6, IL-13, IL-6 and IL-4 in different time were observed and analyzes.</p><p><b>RESULT</b>Compared with the control group, the level of IL-12 and IL-2 was significantly increased after treatment of oral Chinese materia medica (P < 0.01), however, the level of TNF-alpha, IL-13, IL-4, and IL-6 was decreased after treatment (P < 0.01). During one years follow-up study, the frequency of respiratory infection every year of therapy group was significantly decreased than that of control group.</p><p><b>CONCLUSION</b>Chinese materia medica could prevent infantile recurrent respiratory tract infection effectively, increase humoral immunity function and ensure normal growth in children.</p>