Final answer:
Conditioning hair immediately before a permanent wave treatment can interfere with the chemical process by affecting how the hair absorbs and reacts to the chemicals, potentially resulting in a weaker or less defined wave.
Step-by-step explanation:
Conditioning immediately prior to performing a permanent wave service can potentially affect the outcome due to the way treatments interact with the hair's structure. The process of creating temporary and permanent waves involves manipulating the hydrogen and disulfide bonds within hair strands. For a temporary wave, water molecules enter the keratin strands and disrupt hydrogen bonds when the hair gets wet. As it dries and new hydrogen bonds form, the hair can maintain the new shape temporarily.
However, in the case of a permanent wave, the hair undergoes a chemical change. A reducing agent, usually ammonium thioglycolate, breaks the disulfide bonds. This allows the hair to be reshaped and then, with the application of an oxidizer, for those bonds to reform and lock in the new shape. If conditioning occurs right before this service, it may impact the ability of the hair to properly absorb and react to the chemical treatment, potentially leading to a less defined or weaker wave.