Does microetching enamel reduce bracket failure when indirect bonding mandibular posterior teeth?

AIM: To determine if microetching the mandibular premolars and first molars prior to acid-etching reduced bracket failures during the first six months of orthodontic treatment. METHODS: Sixty four patients with 384 mandibular first molar and premolar brackets were used in a split-mouth study design. In each patient the teeth on one side were acid-etched and the contralateral teeth were microetched prior to acid-etching. The microetched side was alternated in successive patients. The brackets were indirect bonded to the teeth on both sides. First time bracket failures were recorded over a 6-month period. RESULTS: Two brackets (1 per cent) came loose on the microetched enamel side and four brackets (2.1 per cent) failed on the conventionally acid-etched side. This difference was not clinically or statistically significant (p = 0.41). CONCLUSION: The addition of microetching prior to acid-etching does not result in fewer bracket failures during the first six months of treatment.

Self-ligating brackets: present and future.

Recently, there has been a resurgence in the use of self-ligating (SL) brackets, which were introduced in the early 20th century. From a synthesis of both in-vitro and in-vivo evidence-based literature, we present general concepts, principles, and axioms. The references to "active" and "passive" SL brackets are explained and juxtaposed in relation to their perceived advantages and disadvantages. We also present new concepts in regard to the future of SL brackets: combination bracket system, hybrid system, and selective use of SL brackets.

Self-ligating vs conventional twin brackets during en-masse space closure with sliding mechanics.

INTRODUCTION: The aim of this study was to compare the rate of en-masse space closure with sliding mechanics between passive self-ligating SmartClip brackets (3M Unitek, Monrovia, Calif) and conventional twin brackets ligated with stainless steel ligatures. METHODS: Nineteen patients including 20 arches participated in this prospective trial with 0.018-in slot brackets. All patients had first premolar extractions in at least 1 arch, with the second premolar and the first molar distal to the extraction site bonded with SmartClip brackets on 1 side and conventional twin brackets on the other. The sides were alternated with each consecutive patient. Space closure was achieved on 0.016 x 0.022-in stainless steel wires with nickel-titanium coil springs activated 6 to 9 mm. The patients were recalled every 5 weeks until 1 side had closed. The distances from the mesial aspect of the canine bracket to the distal aspect of the first molar bracket were recorded before and after space closure, and an average rate of space closure per month was calculated. RESULTS: Thirteen patients completed the trial (14 arches); the median rates of tooth movement for the SmartClip bracket side (1.1 mm per month) and the conventional twin bracket side (1.2 mm per month) were not significantly different (P = .86). CONCLUSIONS: There was no significant difference in the rate of en-masse space closure between passive SmartClip brackets and conventional twin brackets tied with stainless steel ligatures.

A clinical trial of Damon 2 vs conventional twin brackets during initial alignment.

The objective of this study was to compare the effectiveness and comfort of Damon 2 brackets and conventional twin brackets during initial alignment. Sixty consecutive patients participated in a split mouth design. One side of the lower arch was bonded with the Damon 2 bracket and the other with a conventional twin bracket. The sides were alternated with each consecutive patient. The irregularity index (II) was measured for each half of the arch at baseline, at 10 weeks at the first archwire change, and at another 10 weeks at the second archwire change. Any difference in discomfort was assessed within the first few days of archwire placement and again at the first archwire change. Comfort on the lips, preferred look, and bracket failure rates were also recorded. The twin bracket was more uncomfortable with the initial archwire (P = .04). However, at 10 weeks, substantially more patients reported discomfort with the Damon 2 bracket when engaging the archwire (P = .004). At both archwire changes at 10 and 20 weeks (P = .001), the conventional bracket had achieved a lower II than the Damon 2 bracket by 0.2 mm, which is not clinically significant. Patients preferred the look of the twin bracket over the Damon 2 (P < .0005) and more Damon 2 brackets debonded during the study (P < .0005). The Damon 2 bracket was no better during initial alignment than a conventional bracket. Initially, the Damon 2 bracket was less painful, but it was substantially more painful when placing the second archwire and had a higher bracket failure rate.

SmartClip versus conventional twin brackets for initial alignment: is there a difference?

OBJECTIVE: To compare the effectiveness of SmartClip brackets and conventional twin brackets for initial alignment of the lower arch. METHODS: Fifty-eight patients participated in this prospective trial. The patients were assigned alternately to either a group treated with SmartClip MBT prescription brackets or a group treated with conventional MBT twin brackets. Lower anterior irregularity was measured at the start of treatment, 10 weeks later at the first archwire change and 20 weeks after the start of treatment at the second archwire change. RESULTS: There was no difference in irregularity at the start of treatment. At 10 weeks subjects treated with conventional brackets had a lower irregularity index than subjects treated with SmartClip brackets (Mean difference: 0.7 mm; p = 0.005). After 20 weeks there were no statistically significant differences in irregularity between the two groups (Mean difference: 0 mm; p = 0.82). CONCLUSION: The SmartClip bracket was no more effective at reducing irregularity during the initial stage of treatment than a conventional twin bracket ligated with elastomeric modules or stainless steel ligatures.

A comparison of two indirect bonding adhesives.

The aim of this study was to compare and evaluate the clinical failure rates of the chemically cured composite bonding resin Maximum Cure (MC) and the flowable light-cured resin Filtek Flow (FF) when used in an indirect bonding technique. A total of 112 consecutive patients satisfying the selection criteria were assigned to alternating groups in a split-mouth study design. In Group 1, the maxillary right and mandibular left quadrants were indirectly bonded using MC adhesive, whereas the contralateral quadrants were bonded using FF adhesive. In Group 2, the sides bonded were opposite to those in Group 1. One patient was lost from group 1, so the adjacent patient from group 2 was excluded. Over a six-month observation period, all loose brackets were recorded and the data compared with a Wilcoxon signed ranks test. Of the 2468 brackets placed, 36 with the MC adhesive came loose (2.9% failure rate) compared with 30 in the FF group (2.4% failure rate, P = .95). In the maxillary arch, 12 brackets from the MC quadrants came loose vs 24 in the FF (P = .02). In the mandibular arch, 24 brackets from the MC quadrants came loose during the six-month observation period compared with six from the FF quadrants (P = .03). These results suggest that both adhesives examined in this study (MC and FF) were suitable for the indirect bonding of brackets. The failure rates were low for both adhesives, so either could be recommended for clinical use, the choice being dictated more by operator preference.