Plaque is a sticky film of bacteria that forms on the teeth. Brushing and flossing everyday help to get rid of plaque. If not removed, it will get hard to form Tartar. If plaque/calculus (also known as Tartar) remains on the teeth, it leads to inflammation in the gums which is called Gingivitis .If gingivitis is left untreated, inflammation from gums goes to the bone surrounding the tooth leading to Periodontitis. Scaling and polishing is a procedure to remove plaque/tartar/stains from the teeth.