There was insufficient evidence to assess the effect of bonding modality on demineralization rates .
CONCLUSIONS There is weak evidence indicating higher odds of failure with self-etch primer than acid etch over 12 months in orthodontic patients , and there is strong evidence that a self-etch primer is likely to result in a modest time savings ( 8 minutes for full bonding ) compared with acid etch
INTRODUCTION The use of self-etch primers has increased steadily because of their time savings and greater simplicity ; however , overall benefits and potential disadvantages and harms have not been assessed systematic ally .
In this study , we review ed r and omized controlled trials to assess the risk of attachment failure , bonding time , and demineralization adjacent to attachments between 1-stage ( self-etch ) and 2-stage ( acid etch ) bonding in orthodontic patients over a minimum follow-up period of 12 months .
Six and 12 months' evaluation of a self-etching primer versus two-stage etch and prime for orthodontic bonding: a randomized clinical trial.
The aim of the study was to compare the mean clinical chair-side time required for bracket bonding and the mean bond failure rate at 6 and 12 months of stainless steel brackets with a micro-etched base bonded with a light-cured composite using a self-etching primer ( SEP ) or a two-stage etch and prime system .  Fifty-one subjects who required upper and /or lower pre-adjusted edgewise fixed appliances were recruited in a single centre r and omized clinical trial . The trial was a single-blind design , involving a within-patient comparison of the two bonding systems with each patient r and omly allocated the two bonding systems for each side of the mouth ( all teeth except molars ) . The two bonding techniques used were st and ardized throughout the trial and all bracket bonding was performed by a single operator . Bonding time was recorded using a digital timer . The bond failure rate of a strictly paired sample was recorded at 6 and 12 months for each patient . The mean bracket bonding time per patient with the SEP was significantly less than that with the two-stage bonding system ( mean difference 24.9 seconds ; 95 per cent confidence interval 22.1 - 27.7 seconds ; paired t-test P < 0.001 ) . The overall bond failure rates at 6 and 12 months with the SEP were 0.8 and 1.6 per cent , respectively , and for the two-stage etch and prime 1.1 and 3.1 per cent , respectively . At 6 months , the mean bond failure rate per patient with the SEP was 0.81 per cent and with the two-stage bonding system 0.96 per cent ( P = 0.87 ; Wilcoxon signed rank test ) . At 12 months , the mean bond failure rate with the SEP per patient was 1.54 per cent and with the two-stage bonding system 2.78 per cent ( P = 0.33 ; Wilcoxon signed rank test ) . The mean bracket bonding time with the SEP per patient was significantly shorter than that of the two-stage bonding system ( P < 0.001 ) . The difference between the overall bond failure rate and the mean bond failure rate per patient for the two bonding systems was not statistically nor clinical ly significant at 6 and 12 months ( P = 1.00 and P = 0.125 , respectively ; McNemar 's test )
There was insufficient evidence to assess the effect of bonding modality on demineralization rates .
CONCLUSIONS There is weak evidence indicating higher odds of failure with self-etch primer than acid etch over 12 months in orthodontic patients , and there is strong evidence that a self-etch primer is likely to result in a modest time savings ( 8 minutes for full bonding ) compared with acid etch
INTRODUCTION The use of self-etch primers has increased steadily because of their time savings and greater simplicity ; however , overall benefits and potential disadvantages and harms have not been assessed systematic ally .
In this study , we review ed r and omized controlled trials to assess the risk of attachment failure , bonding time , and demineralization adjacent to attachments between 1-stage ( self-etch ) and 2-stage ( acid etch ) bonding in orthodontic patients over a minimum follow-up period of 12 months .