Northridge Dentist. Dr. Kevin Gropp provides Gum Disease, gum disease treatment, periodontal disease, treatment for gum disease, gingivitis to patients suffering from gum disease, receding gums, tooth loss, bleeding gums, sore gums, sensitive gums in Northridge, Reseda, North Hills, Granada Hills. Northridge Dentist providing Gum Disease in Northridge, California.