Effect of the simulated Indian and Mediterranean climates on the Shore A hardness of maxillofacial silicone

PURPOSE: The purpose of this study was to assess and compare the effect of the simulated Indian and Mediterranean climates on the Shore A hardness of a commercially available nonpigmented room temperature vulcanizing maxillofacial silicone. MATERIALS AND METHODS: Sixty specimens were fabricated from A-2000 silicone material (Factor II), using a stainless steel mold of dimension 20 mm × 2 mm. The initial Shore A hardness was noted using a digital durometer. Thirty samples were subjected to the simulated Mediterranean climate (Group I), and the remaining thirty samples were subjected to the Indian tropical climate (Group II) in an accelerated weather chamber to simulate 1 year of clinical use. Final Shore A hardness was noted. A one-way ANOVA and Bonferroni post hoc tests were performed for the Shore A hardness at P < 0.05. RESULTS: The mean initial Shore A hardness for both the groups was 24.9833. After accelerated weathering, Group I showed mean Shore A hardness of 33.0000 whereas Group II showed mean Shore A hardness of 38.0000. CONCLUSIONS: The Shore A hardness of Factor II, before and after accelerated artificial weathering, was statistically significant at 0.05 level (P < 0.05). The change in Shore A hardness was greater in the simulated tropical climate group (Group II) as compared to the simulated Mediterranean climate group (Group I) but within clinical limits.