Effect of mixing method on the working time and setting time of alginate impression materials / 实用口腔医学杂志

Working time of normal setting impression materials was 71 (hand mixing,30 s),66 (Alghamix,20 s) and 53 (Algimax-Ⅱ,8 s) seconds respectively.Working time of fast setting impression materials was 56 (hand mixing,30 s) and 51 (Alghamix 20 s) seconds respectively.Setting time of normal setting impression materials was 163 (hand mixing,30 s),160(Alghamix 20 s) and 124(Algimax-Ⅱ,8 s)seconds respectively.Setting time of fast setting impression materials were 131 (hand mixing,30 s) and121 (Alghamix 20 s) seconds.The working and setting time of normal setting impression materials mixed by hand mixing(30 s) and auto-mixing (Alghamix 20 s;Algimax-Ⅱ,8 s) and fast setting impression materials mixed by hand mixing(30 s) and with auto-mixing using Alghamix (20 s) may satisfly clinical requirement.

Ranula – threefold habituation.

Intraoral swellings present as a diagnostic challenge to the clinician, the most bourgeois being mucocele & ranula. An intraoral ranula has been defined as a retention cyst due to ductal obstruction & fluid retention of the sublingual salivary gland on the floor of the mouth. The name “ranula” has been derived from the latin word “Rana” meaning “Frog.” We hereby report a case of triennial recurrent ranula located in the floor of mouth, treated successfully by surgical excision by injecting an irreversible impression material to delineate the cystic lining of the lesion, after which the patient recovered unvariedly.

Empirical study of alginate impression materials by customized proportioning system

PURPOSE: Alginate mixers available in the market do not have the automatic proportioning unit. In this study, an automatic proportioning unit for the alginate mixer and controller software were designed and produced for a new automatic proportioning unit. With this device, it was ensured that proportioning operation could arrange weight-based alginate impression materials. MATERIALS AND METHODS: The variation of coefficient in the tested groups was compared with the manual proportioning. Compression tension and tear tests were conducted to determine the mechanical properties of alginate impression materials. The experimental data were statistically analyzed using one way ANOVA and Tukey test at the 0.05 level of significance. RESULTS: No statistically significant differences in modulus of elastisity (P>0.3), tensional/compresional strength (P>0.3), resilience (P>0.2), strain in failure (P>0.4), and tear energy (P>0.7) of alginate impression materials were seen. However, a decrease in the standard deviation of tested groups was observed when the customized machine was used. To verify the efficiency of the system, powder and powder/water mixing were weighed and significant decrease was observed. CONCLUSION: It was possible to obtain more mechanically stable alginate impression materials by using the custom-made proportioning unit.

Study on modified method of making oral impression while patients wearing fixed appliances / 重庆医科大学学报

Objective:To modify the method of making oral impression and improve the successful rate.Methods:Rubber band was used to fill in the brackets before making oral impression.Two kinds of ways,the modified and the traditional,were used for each patient.Then the successful rate was compared between two groups.Results:There is statistically significant difference in the successful rate between the traditional group and the modified group ( P