It depends. There is no scientific evidence that the traditional polishing with rubber cup on a dental handpiece and polishing paste has any therapeutic value. In fact, numerous reports have shown that plaque left on the teeth is not a barrier to fluoride uptake; and there is no difference in rate of tooth decay between patients who receive a rubber cup polish and those who don't. Also, polishing with rubber cup or brush and paste is somewhat abrasive and may remove the outer, most fluoride rich layer of enamel, which is the most protective against cavities. Polishing with a rubber cup and paste is helpful to remove stain, if it exists. Scaling with a hand instrument is more gentle on the enamel and also removes calculus (if it is present) and some stain.
This has been the policy of the American Academy of Pediatric Dentistry since 1986: