\documentclass{scrartcl}
\usepackage[T1]{fontenc}
\renewcommand{\rmdefault}{aett}
\catcode96=13
\def``{{\usefont{OT1}{cmss}{m}{n}\symbol{92}}}
\catcode39=13
\def''{{\usefont{OT1}{cmss}{m}{n}\symbol{125}}}
\begin{document}
        ``This is my example sentence.''
\end{document}

