What is the difference between Methamphetamine and the prescribed ADHD medication Adderal Amphetamines?

1) What are the long term affects of Methamphetamine versus those of ADHD Amphetamine?

2) Will prescription Amphetamines cause de-calcification of bones or teeth?

3) Would Methamphetamine have less destructive long term physical affects if it were pharmaceutical grade opposed to street-grade?
I am curious because I have a prescription of Adderall.

: http://alcoholdrugstreatment.info/what-is-the-difference-between-methamphetamine-and-the-prescribed-adhd-medication-adderal-amphetamines