i.confluence-wiki {
    background: url('../images/icon_small.png') no-repeat center;
}

.confluence-wiki i {
    background-repeat: no-repeat;
    background-position: center;
    background-size: 18px;
    width: 18px;
    height: 18px;
    display: inline-block;
    font-size: 1px;
    position: relative;
    right: -12px;
}