I need to dye my hair after having SMP as it is very grey. Can I use a non chemical dye?

SMP into scar tissue can work very well. Pigment can take to scar tissue differently to virgin skin. It may take more sessions to build up a solid foundation for the pigment. Possibly the pigment will not be as stable. It is important to ind an experienced SMP technician in scar repairs. 

Natural affects such as sunlight, high exposure over time including chlorinated swimming pools. But also the quality of the pigment used and how it is applied to your skin. As well as your natural skin characteristics including if the pigment is being placed in to scar tissue. 

It is best to ask your surgeon about post operative care as each doctor has their unique regimen.  Laser cap should not be an issue.