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.

The proposed study is a first-in-human safety evaluation of Polymer-Induced Liquid Precursor (PILP)-releasing dental materials for the treatment of deep carious lesions in adult posterior teeth.

The study will enroll adult patients diagnosed with carious lesions involving the dentin. Participants will be randomly assigned to one of three intervention groups. The primary objective is to assess the safety of PILP application, with a hypothesis that PILP can be safely used without causing adverse events to the tooth or patient.

Participants will undergo a series of visits starting with a comprehensive screening and consent process, followed by the assigned dental procedure involving caries removal and restoration. Follow-up evaluations will occur at 48 hours, 1 month, 3 months, and 6 months post-procedure to monitor for any symptoms or adverse outcomes.

Inclusion Criteria:

1. Stated willingness to comply with all study procedures and availability for the duration of the study

2. Male or female, aged 18 to sixty-four

3. In good general health as evidenced by medical history (ASA 1 or 2)

4. With at least one posterior tooth with caries to dentin

   1. The tooth must have a pulpal diagnosis of pulpal health (no irreversible pulpitis or periapical radiolucency)
   2. The tooth should have no existing restorations
   3. The caries should be a Class I or class V single surface lesion
   4. The tooth should be planned for restoration with intra-coronal restoration (composite or RMGI restoration)
   5. The tooth should be deemed as needing a restoration based on ICDAS (International Caries Detection and Assessment System)

Exclusion Criteria: Known allergic reactions to components of the study device