Whitney Houston's Final Doctor Visits For Teeth Whitening, Sore Throat

Whitney Houston made three visits to the doctor in the week prior to her death, but the trips had NO illicit purpose -- she had a sore throat and got her teeth whitened.

Both family and law enforcement sources tell TMZ ... Whitney was recording the title track to "Sparkle" and got a sore throat ... so she went to a doctor to get it checked out. We're told the doctor gave Whitney an Rx for Amoxicillin.

Whitney was also scheduled to film a commercial for her sister-in-law's candle line, so she went to a dentist twice to get her teeth whitened and cleaned.

And law enforcement sources have reiterated to TMZ ... Whitney was NOT doctor shopping for prescriptions and they believe none of the doctors crossed the line in their treatment of her.

As we first reported, Beverly Hills cops retrieved 6 medication bottles in Whitney's room, including Xanax and Amoxicillin. She also had Midol and ibuprofen.

And as we reported, it is increasingly looking like Whitney mixed Xanax and alcohol before getting in the tub, and that she may have died from a reaction to the drugs ... not from drowning.