# Cytotoxicity of ammonia‐ and water‐based silver fluoride treatments

## TL;DR

This study examines how ammonia- and water-based silver fluoride treatments affect cell viability through dentin and directly, finding that water-based treatments are less toxic.

## Contribution

The study introduces a novel evaluation of silver fluoride treatments' cytotoxicity using dentin-barrier and direct exposure methods.

## Key findings

- Water-based silver fluoride (SF) showed the highest cell viability in the dentin-barrier test.
- Ammonia-based silver fluoride (SDF) and SF exhibited no cytotoxicity at low dilutions in direct tests.
- Adding potassium iodide increased cytotoxicity in both treatment types.

## Abstract

This study aims to investigate the trans‐dentinal and direct cell viability of ammonia‐ and water‐based silver fluoride treatments. Deep dentin discs were prepared, balanced for permeability and autoclaved. Three‐dimensional cultures of odontoblast‐like cells were transferred to the pulpal aspect of the dentin slices inside perfusion split chambers designed for dentin‐barrier cytotoxicity test, following ISO 7405. An experimental resin‐based glass ionomer cement and a polyvinylsiloxane impression material served as positive and negative controls, respectively. The experimental treatments included: (i) ammonia‐based silver fluoride = SDF, (ii) SDF + potassium iodide = KI, (iii) water‐based silver fluoride = SF, and (iv) SF + KI. Treatments were applied to the occlusal surface of dentin discs and cell viability (%) was assessed after 24 h using the methylthiazolium (MTT) assay. The cytotoxicity of dilutions (10−3, 10−4, and 10−5) were evaluated with direct exposure, using the same cell line following ISO 10993‐5. SF treatment revealed the highest cell viability among the treatment groups for the dentin‐barrier test. In direct cytotoxicity test, SDF and SF treatments exhibited no cytotoxicity at 10−4 and 10−5 dilutions. The addition of KI increased cytotoxicity. Ammonia‐ and water‐based silver fluoride treatments, particularly in deep cavities, should be applied with caution.