Orthodontic bracket failure with and without primer during six months of fixed appliance treatment

To compare orthodontic bracket failure rates with and without primer in patients undergoing fixed appliances treatment. This split-mouth randomized controlled trial was conducted on 42 participants. Diagonal quadrants were randomly assigned to either the primer (control) or non-primer (experimental) group. Allocation was concealed in opaque envelopes and revealed at the time of intervention. Both genders, aged 12-30 years, and visiting for the management of malocclusion were included. Patients with dental anomalies, caries, or restorations were excluded. The direct bonding technique was used for the placement of conventional metallic brackets. Participants were followed up for six months, with monthly visits, and bracket failure within each group was recorded. Generalized estimating equation logistic regression was used to account for clustering of multiple attachments within participants and to estimate odds ratios. A total of 42 participants contributing 840 orthodontic attachments were analyzed over six months. Mean age was 17.81 ± 4.09 years, and 52.4% were female. Monthly attachment failure rates were low in both groups, ranging from 3.8% to 4.3% in the primer group and 3.6% to 6.0% in the non-primer group, with no significant unadjusted differences at any month. In multivariable generalized estimating equation analysis, bonding method was not significantly associated with attachment failure (non-primer vs primer: OR = 1.24, 95% CI = 0.72-2.13; p = 0.435). Male participants (OR = 2.31, 95% CI = 1.28-4.18; p = 0.005) and those aged ≤ 17 years (OR = 2.18, 95% CI = 1.22-3.91; p = 0.008) had significantly higher odds of failure. Failure risk declined modestly over time (OR = 0.95, 95% CI = 0.92-0.99; p = 0.028). No significant interaction effects were observed. Over a six-month follow-up period, omission of primer did not significantly increase orthodontic bracket failure rates. Male participants and younger patients showed a higher risk of bracket failure, irrespective of bonding method.