New to Java

In my IM application I have two threads: one is for receiving and second for sending messages. Both threads use an object which is queue. Receiving thread always scan the queue checking for new messages. To avoid 100% CPU load I use sleep(100) method:

class RecvThread extends Thread {
    /* Only this method is displayed, but has more methods */
    public void run() {
        while (fRunThread) { /* fRunThread declared as boolean */
            try {
                sleep(100);
                synchronized (pq) {
                    packet = pq.pull();
                }
                if (null == packet) {
                    continue;
                }
                notifyPacketHandlers(packet);
            } catch (InterruptedException ex) {
            }
        }
    }
}

Later I found yield() method. Will that yield() method work same like sleep(100) in my case? I.e. if I will use the code

class RecvThread extends Thread {
    /* Only this method is displayed, but has more methods */
    public void run() {
        while (fRunThread) { /* fRunThread declared as boolean */
            yield();
            synchronized (pq) {
                packet = pq.pull();
            }
            if (null == packet) {
                continue;
            }
            notifyPacketHandlers(packet);
        }
    }
}

will it work same like the previous?
Thank you.