Is bicarbonate (sodium bicarbonate) of soda corrosive to tooth enamel?

Abrasive? : It is abrasive, which is why it is often used in whitening toothpastes.

The carbonation...: Is not harmful to the teeth as far as i know. However, some people do not like the carbonation in soda, so they will swish. I call them coke swishers. This action can lead to rapid decay and breakdown of the mandibular first molars as the coke is swished right above these teeth. To make it worse, these are the first permanent teeth to come into a child's mouth.

Not really.: It will "polish" more than corrode. Microscopically, may show some "grinding" but not significant as to worry about it.

Bicarbonate (sodium bicarbonate) of soda: Bicarbonate (sodium bicarbonate) of soda is basically baking soda which is abrasive and can be harmful to enamel if used too regularly and or too vigorously, although it is in some "whitening" toothpastes it really does little to whiten the enamel rather is a good polishing agent to remove stain and make your teeth appear whiter or brighter because they are not as dirty.