Good article by Drs. Centeno and Freeman. Dr. Freeman is hosting Ask the Doctor this month.
http://www.regenexx.com/wp-content/uploads/2011/01/Glass-Magazine-Repairing-Life-Jan-2011.pdf
http://www.regenexx.com/wp-content/uploads/2011/01/Glass-Magazine-Repairing-Life-Jan-2011.pdf