Are dry mouth toothpaste/mouthwashes like biotene / bioxtra safe for long term use even after having a dry mouth? any possible harm to salivary gland?

Contin. biotene: Biotene is safe to use long term so keep using it if it is solving your dry mouth problem. Should not cause any problems to salivary glands, but if your mouth is dry, then there may already be problem with gland. Often decreased salivation is a side effect of another medication you are taking.

Biotene safety: As a product manufactured and distributed under the auspices of the fda, biotene and its related products must meet minimal safety requirements set by that agency. "dry mouth" is a common malady, is often multifactorial in its etiology, and often there are concomitant diseases which contribute to the severity of the problem. See your dentist for a complete evaluation of your situation.