Influence of a nonrinse conditioner on the bond strength of brackets bonded with a resin adhesive system.

The objective of this study was to compare the effect of a nonrinse conditioner (NRC) and the conventional acid-etch technique on the shear bond strength and the adhesive remnant on the tooth after debonding brackets bonded with the resin orthodontic adhesive system Transbond XT. A total of 40 human premolars were divided into group I, phosphoric Acid/Transbond XT (n = 25) and group II, NRC/ Transbond XT (n = 15). Shear bond strength was measured with a universal test machine with a crosshead speed of 1 mm/min. The adhesive remnant was quantified using image analysis equipment. Scanning electron microscope (SEM) observations were also carried out to observe enamel surfaces treated with each product. No significant differences were observed in the bond strengths of the two groups evaluated. The amount of adhesive remnant on the tooth after debonding was significantly less when conditioning the enamel with NRC compared with phosphoric acid. SEM observations showed that the NRC produced a more conservative etch pattern than phosphoric acid.