Influences of TiO2 and SiO2 nanofillers on the hardness and surface roughness of maxillofacial silicone elastomers after two years of outdoor tropical weathering: An in vitro study - Mohammed Mousa; Belal Elmarhoumy; Mahmoud Salloum; Abdalwhab Zwiri; Mohammed Sghaireen; Thamir Bahattab; Ahmed Almutairi; Njoud Almuzaini; Johari Abdullah (PLoS ONE, 2026)