A retainer is a device to keep your teeth from changing position, it does not help to correct a bite or close a gap. Depending on your x-rays, photos, and facial charting you may or may not need braces. Some patients can use just a bite-block, while some needs to do braces even after biting on a bite-block.
You can remove the mesiodens and have your teeth aligned, but for how long you need to wear the braces depend on your cephalometric film result and charting. There are cases where you can close the gap with braces faster by rotating or removing and replanting a tooth.
If opt for extraction, then time and cost for orthodontic will be shorter and cheaper. If opt for non-extraction, then the time and cost for the treatment will be longer and more expensive; a head gear will be needed. Have a doctor look at tooth #30 before doing any ortho. treatment.
The price for Zoom in-office whitening varies between individual offices as well as by location. You may even find advertised prices ranging from $99 to $600 but take precaution when selecting where to go and do not base your selection solely on price. Finding an office that you can trust and feel comfortable with for any type of procedure is very important. You can ask for referrals from family, friends and co-workers, or even visit the prospective offices and ask questions you may have prior to deciding where to complete treatment so as to achieve the most pain-free and satisfactory experience that is worth the price you pay.
Zoom Teeth Whitening is fairly painless but I have heard and read of many painful experiences which disheartens me and affects many dentists and offices that do uphold high quality and standards when conducting the procedure.