Dimensional Stability and Detail Reproduction of PVS Manipulated with T-mixer Tip

Objectives: The aim of this study was to evaluate the dimensional stability, detail reproduction and residual weight difference of different polyvinyl siloxanes manipulated with MIXPAC T-Mixer™ mixing tip compared to the conventional mixing tip.

Methods: Six different silicones were used: Virtual® Monophase and Light Body, Express™ XT Regular and Light Body and Panasil^® initial contact Regular and Light. The silicones were mixed with 2 different mixing tips: conventional and MIXPAC T-Mixer™ (n=10). The samples were fabricated using a metallic matrix according to the specification #19 of ANSI/ADA and ISO 4823:2015. The dimensional stability was calculated based on the measurement of lines extension of the metallic matrix reproduced in the impression. Details reproduction was evaluated through analysis of continuity and reproducibility of those lines. The analysis were done immediate, 7 and 14 days later. The residual weight difference was obtained by the difference of the initial (before mixing) and final weight (after manipulation and complete polymerization) of both mixing tips. Data were submitted to statistical analysis (α= 0.05).

Results: The results showed lower residual weight using MIXPAC T-Mixer^TM compared to the conventional tip. The amount of residual material into MIXPAC T-Mixer^TM tip was 24% (Virtual Monophase) and 30% (Panasil Light) lower than into conventional tip. Similar dimensional alteration of silicones was found for both MIXPAC T-Mixer^TM and conventional tips, except for Virtual Light at immediate analysis that presented lower immediate dimensional alteration compared to the 7-day and 14-day analysis and Panasil Light showed higher values of dimensional alteration compared to the other materials, especially when mixed with MIXPAC T-Mixer^TM tip at 14-day analysis.

Conclusions: The MIXPAC T-Mixer^TM tip provided lower residual weight of materials compared to conventional tip and the light impression materials presented lower dimensional alteration when mixed with T-Mixer^TM tip compared to conventional tip. Poor detail reproduction was found after 14 days.