Abstract: The invention provides a pretreatment method and primer that is applied directly to the hard tissue. The invention has particular utility for adhering to or coating sclerotic dentin and cervical enamel or for adhering to or coating hard tissue in a high humidity environment. The primer enables formation of extremely strong bonds to dentin. The method comprises the steps of:(a) applying to the hard tissue adhesively effective amounts of an acid and a water-dispersible film former comprising a polymer and(b) hardening the film former.Primer compositions are provided for use in this method, comprising a mixture of an acid and a film former comprising a polymer prior to hardening, the mixture being in the form of a film atop the hard tissue.