Periodontal Parameters Alterations with Use of Conventional Bracket and Self-ligating Brackets

Introduction: Different bracket systems are available in the market claiming to have some advantage over the other. Conventional brackets and the self-ligating brackets are the most common. Though both the systems work basically similarly, the difference between the two system is principally in the ligating technique. The advantage of conventional brackets claimed are faster tooth movements and improved oral health of the patient. Materials & Method: A total number of 20 patients were shorted from the waiting list meeting the selection criteria. With the help of random number generator, two groups with 10 subjects each were created for conventional brackets (0.022 Slot MBT brackets) and self-ligating brackets (0.022 Slot DAMON prescription) respectively. The patients were blinded regarding the selection of the brackets. The brackets were bonded according to the random number allocation. After the bonding, the periodontal parameters i.e. gingival index (GI), plaque Index (PI) were measured again at an interval of 60 (T1) and 120 days (T2). Periodontal indices were calculated by summing the mean score of each examined tooth and dividing by the number of the evaluated teeth. Data collection was done with the help of a periodontal probe. All the records were taken by the same periodontist to avoid inter-examiner variability. To reassure that there is no any intra-examiner variation for periodontal status, the same periodontist re-measured the periodontal parameters again of 10 individuals selected randomly after 7 days from the initial measurements. To examine the intra-examination variability, Dahlberg’s formula was used between the two readings taken at a span of 7 days of the same subjects. The mean value of Plaque index and Gingival index was checked for normal distribution applying KolmogorovSmirnov test. One-way ANOVA test was applied for comparison between and within groups for plaque index and Gingival index during three different period in Conventional brackets and Self-ligating brackets. Post hoc Bonferroni test was applied for multiple comparison. Independent t-test was applied for comparison between conventional brackets and self-ligating brackets to compare the plaque index and gingival index. All data were test were analyzed at P<0.05. Result: There was no any significant difference between T0 and T1 and between T1 and T2 in both the conventional brackets and self-ligating brackets. However, there was statistical difference between the time period from T0 to T2. There was also no any significant difference between conventional bracket and self-ligating brackets in terms of plaque index and gingival index. Conclusion: There are no advantages of self-ligating brackets over conventional brackets in terms of periodontal status.


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Orthodontic Journal of Nepal, Vol. 9 No. 2, July-December 2019 the cause of microbial harvesting. [9][10][11] Active forces are applied with the help of brackets on the tooth leading to its desired movements. Many bracket systems are available and the most common are the conventional brackets and the self-ligating brackets. Though both the system work on the same principle, the principle difference is the ligating system. Different system of orthodontic treatment has been advocated claiming to be superior for oral hygiene control than the rest. 8,12,13 Most commonly, conventional brackets are used as it is relatively cheaper than the self-ligating bracket.
However, since ligature ties or modules are not needed in self-ligating brackets, it is claimed that bacterial harvest is less in the self-ligating brackets compared to conventional brackets. 14,15 The self-ligating brackets claim to be more oral hygiene friendly as it does not have any external ligating system. However, in conventional brackets, either modules or the ligature ties must be used to activate the force into the bracket which is supposed to be a nidus for bacterial accumulation. However, there are some studies that claim that self-ligating brackets harvest more bacteria in comparison to conventional brackets. 16 Many studies have compared the plaque index, gingival index, gingival bleeding index and gingival crevicular fluid volume in two separate groups of patients with conventional and self-ligating brackets.
The study has shown mixed results. 11,[16][17][18] In Nepal including the orthodontic unit of Dental Department of National Academy of Medical Sciences (NAMS), the most common brackets used are the conventional brackets and generally modules and ligature ties are used for activation of force to the teeth rather than the locking slots of the self-ligating brackets. The main advantage of conventional bracket is the cheaper price. Though previous studies have shown mixed results regarding its effect on periodontal parameters, no any studies have done in the context of Nepalese patients. 2,3,9,16 All the previous studies are done in the western world and on different bracket system which may not be relevant to our context here in Nepal because of the paying capacity of the patient, the oral hygiene habits of the patients and the limited budget to our hospital.
This study aims to find out if there is any difference in the alteration of periodontal parameters (Gingival Index and Plaque Index) with conventional brackets and the self -ligating brackets.

MATERIALS AND METHOD
The sample of this study included subjects with Bajracharya  type was kept on a sealed envelope and was opened for the respective patients once they have accepted to be enrolled in the experiment. Approval from the Ethical committee was taken from the university and consent were taken from the patients as well as their parents (if minor) before the subjects were enrolled in the research.
All the patients were given oral hygiene instructions one month before the start of the orthodontic treatment.

Oral hygiene instructions included proper technique
for tooth brushing and the use of interdental brushes.
Re-enforcement of the oral hygiene instructions were given throughout the treatment process. All the patients were restricted for using any mouthwashes throughout the treatment. All the subjects were evaluated for the periodontal parameters by a periodontist before orthodontic procedures and those parameters were taken as control.   (Table 3). All data were test were analyzed at P < 0.05.

RESULT
Dahlberg's formula used to compare intra-examiner variability was found to be in the range of 0.4 to 0.6 between the two readings taken at a span of 7 days of the same subjects. Kolmogorov-Smirnov test for normality distribution was found to be insignificant.
Reject for treatment = 0 Allocation for conventional bracket n=10 Failed to continue treatment n=0 Analyzed n=10 Allocation for Self-ligating bracket n=10    It was interesting to find that PI and GI were not statistically significant within 2 months period in both conventional brackets and self-ligating brackets. But when compared in relation to 4 months, the readings are statistically significant within the group for both conventional brackets and self-ligating brackets (Table 3) However, it was found to be insignificant between the groups (self-ligating and conventional brackets) in both 2 months and 4m months period. (Table 4)

DISCUSSION
The most common method for orthodontic treatment is Similarly, though the measurement for GI was found to be increased between T1 and T2 in both the groups, it was also not statistically significant. However, the measured value was found to be significant when compared with T0 and T1 in both the groups that is at a span of 120 days from the time from bonding the brackets. When the gingival index was compared between CB and SLB brackets at both T1 and T2, it was found to be statistically insignificant.
Plaque Index: Similar to the gingival index, the PI was also found to be increased between T0 and T1 in both CB and SLB though the increased measurement was not found to be statistically significant. Likewise, there is an increment in the measurement between T1 and T2 in both the groups, but it was not found to be statistically

CONCLUSION
There are no any differences between gingival index and plaque index between self-ligating brackets and conventional brackets. The self-ligating brackets have no any advantages over conventional brackets in terms of periodontal status of the patient.