Do not over brush
The main cause for losing enamel is over brushing. Also strong toothpaste could affect the enamel.
For shiny tooth
Apply clove oil thrice a week every day, on all teeth and leave it for some time. Then gargle it with warm water.
Also you can scrub your teeth thrice a week with banana skin, this will make your teeth stronger and shiny.
Turmeric can be used as a tooth powder.
Use nutmeg or clove. Press it under the tooth for some time. Do not gargle or drink cold water.
Asafetida powder mix with lime juice is also beneficial applied in affected areas.