Universal / Multi-mode Adhesives In Descriptive Review: Innovative Or Traditional Systems?

INTRODUCTION: Recently appeared on the market simplified adhesive systems (AS) designated as Universal (UAS) or "Multi-Mode" adhesives. OBJECTIVE: Descriptive review of UAS regarding labelling (composition, solvent, acidity) advantages over Etch&Rinse (ER) and Self-Etch (SE) systems and performance evidences. METHODS: Literature search in MEDLINE/PubMed, Science Direct was conducted, between the years 2010-2015, with the keywords: "Dentin/Enamel bonding agents", "self-etch adhesives," "etch&rinse adhesives", "universal adhesives", "multimode adhesives", "simplified adhesives". Fifty articles were identified. Methodology included publications of meta-analysis, narrative/systematic review, in-vitro and clinical trials. RESULTS: Seventeen publications were selected: one meta-analyse, one systematic review, 13 in vitro and two clinical trials. UAS labelling/pH/solvent were registered: Scotchbond Universal (3M/ESPE); Futurabond U (Voco); Clearfil Universal Bond (Kuraray); XenoSelect (Dentsply); All-Bond Universal (Bisco); G-Bond Plus (GC); Adhese Universal (Ivoclar Vivadent); Peak Universal Bond (Ultradent). In most, the solvent is ethanol with or without water; classified as mild (pH≈2) ultra mild (pH> 2.5) in acidity. Main advantage associated with versatility of instructions for use (ER and/or SE). UAS effectiveness appears to depend on the chemical composition; more research is needed to determine their clinical performance. CONCLUSIONS: UAS do not greatly differ from traditional ER/SE systems; Chemical interaction is a crucial characteristic of UAS to enhance durability of dentin-resin interfaces. Similar performance to some SE, but less than some ER adhesives especially in enamel. CLINICAL IMPLICATIONS: UAS although versatile in application do not match technological innovation when compared to traditional ER and SE. AS innovation requires bio-protective and bio-promoter effects in the enamel and dentin. Keywords: Dentin/Enamel bonding agents, self etch adhesives, etch & rinse adhesives, multimode adhesives, universal adhesives, simplified adhesives