Demand for curly and wavy hair swings with the fashion pendulum. Rearranging naturally straight or wavy hair to be more wavy or curly became very popular about twenty years ago and shows no sighn of abating. The specific shape of your hairs is determined by two types of linkages of the protein molecules in them; strong sulfur bonds and weaker hydrogen bonds. In general, temporary setting procedures, such as the simple use of water to style your hair, hair setting preparation, and even electric rollers depend largely upon affecting the weaker hydrogen bonds. These bonds are first disrupted and then realigned to make the desired straight or curly hair.
Longer lasting changes achieved with permanent waving preparations work by breaking and rearranging the longer sulfur bonds. Setting lotions, which generally contain some kind gum placed in rollers. These ingredients coat your hair and lock out moisture in order to keep the set longer. For the quick sets, electric rollers can give a fair good, if temporary set. The heat of rollers breaks the weaker hydrogen bonds in your hair. Hot-mist rollers are generally better than straight electric rollers because the mist restores some of the moisture to the hair that plain heat normally takes away.
Too frequent use of electric rollers, however, can leave your hair dry and brittle, particularly if you have tinted or bleached hair. Home use of electric curling irons, while safe, may cause problems. In general, curling irons are hotter than electric curler. If the heat is too low to break the protein bonds in your hair, curling will be unsatisfactory. On the other hand, if the heat generated is too high, your hair may become excessively dry, brittle, or even burned. I usually do not recommend curling irons for these reasons.