Maxillofacial Prosthetics Reinforced with Polyhedral Silsesquioxanes (POSS)

Objectives: The goal is to improve the properties of maxillofacial polymers using polyhedral silsesquioxane POSS nanofillers. Methods: The control sample was made by mixing Part A and Part B (1:1, wt/wt) Factor II A-2000 with Factor II Thixo followed by heat curing. POSS modified samples of 0.5, 1, 2 and 5% were formulated as per the following example: Part A was loaded with a vinyl functionalized POSS (1%, w/w), Part B was loaded with a silane functionalized POSS (1%, w/w); modified Part A was mixed with modified Part B in equal weights to form the maxillofacial polymer loaded with 1% POSS. Trouser and tensile samples were evaluated on a universal testing machine with strain rates of 250 and 500 mm/min respectively. The data was analyzed using ANVOA followed by a Tuckey's test (p=0.05). Results: For POSS loading of 0, 0.5, 1, 2, and 5% the load at failure for the tensile test was 167.2, 178.7, 178.7,198.8 and 206.8 newtons and extension at failure was 169.9, 181.7, 183.1, 200.3 and 211.0 (mm) respectively. The load at failure for the trousers test was 47.9, 47.2, 50.0, 35.7 and 29.3 and the extension at failure was 146.2, 173.7, 194.5, 185.3 and 161.6 (mm). Both tests found an effect of the POSS on the mechanical properties. The corresponding analysis for mean extension yielded an overall significant difference (p = .039) and a specific significant difference (.01 < p < .05) between concentration levels 0% and 5%. The data for mean peak load indicated an overall significant difference (p = .033) but no significant differences for pairwise comparisons were detected. Conclusions: POSS has the ability to improve the mechanical properties of maxillofacial polymers. Larger sample sizes are needed to detect specific differences between the samples.