Bisgma-free orthodontic adhesives

Abstract

Three adhesives formulated with Trimethylolpropane Trimethacrylate (TMPTMA) that do not contain BisGMA were developed, whereby the mutagenic and teratogenic risk by the release of bisphenol A is eliminated, and presented a better performance compared to the three commercial adhesives prepared with BisGMA (Adhesive A, Adhesive C and Adhesive B). The invention provides an adhesive used in one-step and provides a system which is formed by a primer and a slurry. The adhesives of the invention were compared with two commercial controls. They were physically characterized by assessing: hardening time, adhesion stress, elastic modulus, sorption and solubility at different pHs (6.8 and 7.7); by the obtained values premature detachments, white lesions below the appliance and microfiltration are avoided; its fluidity, film thickness were evaluated and were compared with those obtained from the three commercial adhesives. Storage stability and thermogravimetric analysis were assessed. The prepared adhesives with TMPTMA are photopolymerizables, thereby providing enough time to the operator to place the appliance in proper position, it is easy to handle, capable of supporting orthodontic biomechanics, has low elastic modulus, enables transitions of heavy arches reducing the risk of involuntary detachment of the appliances, have low viscosity, penetrates on both the brace retentions as those made with acid etching on enamel surface. Presenting adhesion to both the base of the attachments as well as to the enamel, its film thickness is minimal and does not alter the prescription system. When the appliance is removed at the end of the treatment, it does not cause structural damage to the enamel because the adhesive remains on the enamel and can be removed easily with a rotary instrument.