An Evaluation of Smart Clip Self-Ligating Bracket System : Comparison of Treatment Outcome and Patient Response between Self-ligating and Conventional Pre-adjusted Edgewise Appliance

Introduction: A number of studies have been undertaken to evaluate the friction characteristics of self-ligating brackets, however there have been only few studies which have actually evaluated the clinical efficiency of these self-ligating brackets. Objective: To evaluate the clinical efficiency of Smart Clip self-ligating bracket in terms of treatment time, number of appointments, ABO score, and patient perception by comparing it with a pre-adjusted edgewise appliance system (MBT). Materials & Method: A prospective in vivo study in which twelve patients were bonded with Smart Clip self-ligating appliance and twelve patients were bonded with conventional pre adjusted edgewise appliance (MBT). The record of number of visits was maintained for each visit. At the end of treatment all 24 patients were asked to fill a questionnaire consisting of 10 questions. Post-treatment OPG and study models of all cases were evaluated for ABO score. Result: Average treatment time with Smart Clip self-ligating bracket was 4.5 months shorter than conventional pre-adjusted edgewise bracket. Mean number of appointments with Smart-Clip self-ligating brackets were 6.5 less than conventional pre-adjusted edgewise bracket. There was no significant difference in the quality of treatment with both groups having similar ABO scores. Patient perception to treatment in both the groups was also similar, except that patients with Smart Clip appliance system experienced more pain during wire insertion. Smart Clip group patients had greater difficulty in maintaining oral hygiene. Conclusion: Smart Clip bracket system is efficient in reducing the treatment time, but the quality of orthodontic treatment is similar to conventional pre-adjusted edgewise system. Patient perception for both the brackets is similar.


MATERIALS AND METHOD
This was a prospective in vivo study conducted at the Department of Orthodontics, College of Dental Sciences, Davangere, India.
The patients included in the study were selected randomly from the OPD.Patients undergoing first premolar extractions were allotted randomly to both groups.Materials used for the study were treatment records of all 24 patients, post-treatment study models and OPG, ABO scale, viewer box.All 24 patients were bonded in the duration of four months.The records of number of visits were maintained on each visit of the patient.
At the end of treatment all the 24 patients were asked to fill a questionnaire.Post-treatment OPG and study models of all cases were evaluated for ABO score.After the completion of the treatment, patients were given oral instructions together Bhatia V, Kalha AS, Nanda SB: An Evaluation of Smart Clip Self-Ligating Bracket System: Comparison of Treatment Outcome and Patient Response between Self-ligating and Conventional Pre-adjusted Edgewise Appliance with an explanation on how to complete the questionnaire.The questionnaire consisted of 10 questions.The question no. 1 to 6 evaluated a visual analogue scale, whereas question no.7 to 10 were objective questions, in which the patient had to mark any one option.For groupwise comparisons unpaired t-test or Mann-Whitney tests were used wherever appropriate.
Categorical data were analyzed by Fisher's exact test and p-value was kept at 0.05 for statistical significance.

RESULT
Average treatment time to complete treatment with Smart Clip self-ligating brackets was 14 months whereas that with MBT appliance system was 18.5 months (Table I, Graph 1.
The mean number of appointments required to complete to complete treatment as compared to conventional pre-adjusted edgewise brackets.In another study 24 Damon self-ligating brackets required on an average 4.6 fewer appointments than the conventional edgewise brackets.
In this study, the mean ABO score deduction for Smart Clip self-ligating brackets was 17.2, whereas that of MBT appliance was 19.5.The mean difference in ABO score of two groups was 2.3, which was not statistically significant (p=0.32).This means that finish in both the groups was similar.
In another study 27

CONCLUSION
It can be concluded that though Smart Clip bracket system are efficient in reducing the treatment time.The quality of orthodontic treatment is similar to conventional pre-adjusted edgewise system.Patient perceptions for both the brackets are similar.

Orthodontic
Journal of Nepal, Vol. 4, No. 2, December 2014 ABO score was compared between Damon self-ligating brackets and conventional pre-adjusted edgewise brackets.The mean difference between the two groups was 5.31 and was statistically significant.The questionnaire results show that both Smart Clip and MBT group patients had similar perceptions about their treatment.The only significant difference was for question 3 and 5, where the patients in Smart Clip group felt severe pain during the placement of the wire compared to MBT group.This may be due to the presence of NiTi clips in Smart Clip which offers resistance to the placement of the wire.Also the patient in the Smart Clip group had a greater difficulty in maintaining oral hygiene compared to MBT group; which may be due to the increased size of Smart Clip brackets compared to MBT brackets.The reason for reduced treatment time with Smart Clip self-ligating bracket can be due to the passive ligation of the system 42 .The arch wire is "passively" held in the bracket by means of the programmed nickel-titanium clip.Studies have been undertaken to determine the benefits of selfligating brackets.Excellent research has been accomplished by Thorstenson and Kusy. 28Their findings indicate that not only do self-ligating brackets have a performance edge over mini-twin brackets during leveling and alignment, but additionally retain an advantage during sliding mechanics in an experimental basis.Yeh et al 36 in the in vitro study found that Smart Clip had a greater critical angle compared to Damon brackets and Synergy brackets, when coupled with a 0.016 x 0.022" NiTi archwire.Though Smart Clip had a greater critical angle they found no difference in all types of brackets in the binding conditions of second order intrusions.They also found that because the Smart Clip brackets had the greatest clearance of the tested brackets, the clip design resulted in the greatest bracket width (smallest interbracket distance), which decreased archwire flexibility and impeded the frictional resistance values.Lastly, increased pain experienced by patients during wire insertion when using the Smart Clip appliance demonstrates the need for further research involving the engagement forces of the Smart Clip bracket.

Table 1 : Descriptive statistics for differences in treatment time, number of appointments and ABO score based on bracket types Measurement Smart Clip MBT Smart Clip vs. MBT Mean ± SD Median Range Mean ± SD Median Range Mean difference t-value p-value
t: unpaired t-test, *Significant, NS: Not significant

Table 3 : Descriptive statistics for differences in patient responses bases in bracket types
Bhatia V, Kalha AS, Nanda SB: An Evaluation of Smart Clip Self-Ligating Bracket System: Comparison of Treatment Outcome and Patient Response between Self-ligating and Conventional Pre-adjusted Edgewise Appliance OJN treatment with Smart Clip self-ligating brackets was 14.7, whereas that with MBT appliance system was 21.2 (TableI, Graph 2).The mean ABO score for Smart Clip self-ligating brackets was 17.2 whereas that of MBT appliance system was * Fisher's exact test self-ligating brackets.Another study 24 reported a mean reduction in treatment time of 2.8 months with Damon selfligating bracket as compared to conventional pre-adjusted edgewise bracket.In another study 34 the author compared the effectiveness of Smart Clip brackets and conventional twin brackets for initial alignment of lower arch.The author did not find any statistical significant difference in irregularity between the two groups.The authors concluded that Smart Clip was not effective at reducing irregularity during the initial stage of treatment than a conventional twin bracket.