Please advise what is better: cetylpyridinium chloride or sodium fluoride?

Better for what?: They are different compounds with different applicability. Cetylpyridinium chloride is a cationic quaternary ammonium compound used in some types of mouthwashes, toothpastes, lozenges, throat sprays, breath sprays, and nasal sprays. It is an antiseptic that kills bacteria and other microorganisms. Sodium Fluoride is used to make the surface of a tooth less soluble in acid.

Totally different: Cetylpyridinium chloride is an antiseptic, it kills bacteria. Fluoride is a mineral that makes teeth more resistant to acid when it is incorporated into the tooth enamel and also makes it harder for the bacteria to stick to the teeth. You can't say one is better then the other because they are totally different products that are used for totally different things.