A Change in Shore A Hardness of Two Tissue Conditioners

Tissue conditioning materials lose their softness during use in the oral environment due to the combination of several factors, which include loss of alcohol and plasticizer, and absorption of water. Objective: to compare the Shore A hardness value of ViscogelTM with the experimental tissue conditioner material, following their immersion in different immersion fluids and at different powder liquid ratio. Methods: two tissue conditioning materials were prepared at two different powder liquid ratios, 1.36:1 and 1.9:1. Six samples were made for each material at each powder liquid ratios. The samples were stored in distilled water, artificial saliva or olive oil. The H17 Wallace Shore A Hardness Tester was used to measure the Shore A hardness value. It was measured at the interval of 0 hour, 16 hours, 24 hours, 2 days, 3 days, 7 days, 10 days, 2 weeks, 3 weeks, 4 weeks and 5 weeks after the completion of gelation. Univariate analysis of variance was performed for these data. Results: The highest value of Shore A hardness was noted in ViscogelTM which has a powder liquid ratio of 1.9:1 and immersed in olive oil (45.96). The lowest value of Shore A hardness was noted in the experimental material which has a powder liquid ratio of 1.36:1 and immersed in artificial saliva (14.00). Immersion in olive oil shows the highest changes in Shore A hardness value after five weeks; an increase of 18.21. There were significant influences of the powder liquid ratios, immersion fluids and the type of tissue conditioner materials on the hardness value at the end of 5 week observation period. Conclusions: it had been shown that the experimental tissue conditioner material was softer than the ViscogelTM and has minimal changes in Shore A hardness value following five weeks immersion in distilled water, artificial saliva and olive oil.