Olivia Garden iDetangle Hair Brush - Dual-Curve Shape, Adjusts Tension by Hair Type

Q: Does hair dryer melt the bristles?

No, the hair dryer doesn’t melt the bristles. I have 3. I love this brush.

Q: which of the three options is the most advisable to buy to use in curly hair?

My wife's hair is VERY thick and curly and she did best with the Thick version...the black model.

Q: Is there some kind of guarantee? - the body of our brush broke on both sides after only 3 months.

I’m here looking for another brush now for the same reason. I have had 2 break the same way on both sides, so it flops around I cannot use the handle. Very frustrating because I like the brush. I have very fine hair It has never broken a brush in 44 years, now 2 in a year. I got mine from Ulta.