IADR Abstract Archives
Effect of Rigid Rod Polymer on Water-sorption of Denture Polymer
Objectives: Rigid rod polymers (RRP) are based on long stiff molecules (eg. polyphenolene), which can be in denture base polymer used as reinforcing fillers comparable to fiber fillers. This study evaluated the effect of rigid rod polymer fller on the water-sorption and solubility of denture base polymer.
Methods: Bar shaped test specimen (65x10x3 mm3) were fabricated according to ISO 1567 standard from autopolymerised PMMA based denture resin Palapress (Heraus-Kulzer). Specimens for test groups (n=6/group) were made of autopolymerising resin by mixing PMMA filler and particulate fillers of RRP (Parmax, 1240, Mississippi PolymerTechnologies Inc., USA) in ratios of 10 wt%, 20 wt%, 30wt%. An additional test group consisted of specimens made fully of RRP (100wt% RRP) with compression-molded manufacturing method. Control specimens (0wt% RRP) were made of denture base resin as such. The water-sorption of the test specimens was measured after 1, 2, 5, 7, 14, 21, 30, 37 and 44 days of water storage at 37°C. Specimens were dehydrated in the oven at 120ºC for 43 hours to calculate sorption and solubility.
Results: ANOVA revealed significant differences between the groups (p<0.001) in water sorption.
|
% |
Water sorption (wt%) |
Solubility (wt%) |
|
0 % |
2.30 (0.03)a |
0.68(0.04) a |
|
10 % |
2.22 (0.04)a |
0.54(0.14) a |
|
20 % |
2.08 (0.01)b |
0.60(0.04) a |
|
30 % |
2.00 (0.01)b |
0.60(0.01) a |
|
100 % |
0.94 (0.09)c |
0.08(0.06) b |
Superscript letter indicates homogenous subsets (Tukey).
Conclusions: Addition of RRP fillers decreased the water sorption of denture base, whereas solubility was not affected by RRP filler. Specimens made of 100% RRP revealed high hydrophobicity and neglible solubility.