- 37% phosphoric acid etch benzalkonium chloride (bac) provides residual enhanced anti-microbial action. - It also provides mmp Inhibition (activated by acid etching dentine) – this preserves your bond absence of a silica thickener allows etchant to be rinsed away leaving tooth surface free of residue, not affecting bond. - Etch-37 with bac: 37% semi-gel phosphoric acid: 4 syringes (5g ea.), 60 disposable tips. **For further product information, please contact Chat Support**