Superscript bug

When there is a superscripted character in the text I'm pulling from a database, the Helevitica font I'm trying to use isn't respected. I believe it uses the Times New Roman font instead. Snippet below:

Table table = new Table();
            table.DefaultCellTextState.Font = FontRepository.FindFont("Helvetica");
            table.DefaultCellTextState.FontSize = 7;
            row = table.Rows.Add();
            row.DefaultCellPadding = new MarginInfo();
            row.DefaultCellPadding.Top = 6;
            row.DefaultCellPadding.Bottom = 6;
            row.DefaultCellBorder = border;
            row.IsRowBroken = false;

            row.Cells.Add(Db.getColumn<string>(dataRow, "description"));