Dental: besides gum grafting and using sensitive type toothpaste could composite resin placed on teeth decrease its sensitivity?

Probably not: Composite resins have been associated with increased not decreased dental sensitivity. Read this for sensitive teeth strategies: http://www.livescience.com/44377-sensitive-teeth.html

Of course: A properly placed composite filling will last for years and will decrease tooth sensitivity by pre-sealing of dentine with a resin-bonding agent.