Polymer Induced Liquid Precursor (PILP) in Adults in With Dentin Caries

The goal of this clinical trial is to learn if polymer-induced liquid precursor (PILP) can be used safely to treat dentin caries (cavities) in adults. The main question it aims to answer is: Is PILP (conditioner or liner) safe in adult teeth with dental caries? Researchers will compare PILP to a placebo (a look-alike substance that contains no drug) to see if PILP safely treats cavities in teeth. Participants will: 1) Have PILP or placebo applied to their tooth prior to the placement of a filling in the tooth, 2) Complete two telephone calls within three months of filling placement and 3) Visit the clinic at three months and six months after the placement of the filling.