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Regrowth of plaque when using Orthodontic Brackets

Claudet PC, Alió JJ, Iglesias C, Ramírez EM.

Objective: Test the efficacy of JAL 90458 on the regrowth of plaque in patients with orthodontic braces.

Materials and Method: A total of 16 subjects (11 women and 5 men) between the ages of 12 and 39 took part in this study. The study was conducted under clinical trial conditions, double blind, parallel and randomized in balanced groups using a plaque regrowth design. The subjects had a professional teeth-cleaning and were instructed to not use any kind of oral hygiene measures for the next four days, using only the gel that had been assigned to them. We took into account the following parameters: the Quigley – Hein plaque index, modified by Turesky (QHPI-T), Plaque – Bracket Index (PIb) and the Bleeding on Probing Index (BOP). Analysis of the data was done using a Student's t-test, Fisher's exact test and Pearson's correlation coefficient.

Results: Statistically significant differences between the JAL 90458 group and the control gel group were obtained in the QHPI-T (2.52±0.57 vs 1.78±0.79, p<0.05), as well as in the PIb (2.04±0.73 vs 1.27±0.59, p<0.05), and BOP ( 1.24±0.20 vs 0.48±0.24, p<0.05). There was a high correlation between the PIb and the QHPI-T (r=0.94, p<0.01). The linear regression equation to predict the value of the QHPI-T using the PIb was: QHPI-T = 0.568 + 0.956 * PIb. Dry mouth was the most frequent side-effect without significant differences between both groups.

Conclusion: The application of JAL 90458 in patients with orthodontic braces was shown to be effective in the regrowth of bacterial plaque.

Key words: JAL 90458, plaque regrowth, orthodontic braces, clinical trials.

Orthodontic braces alter the oral environment and impede the adequate control of bacterial plaque resulting in caries, gingivitis and decalcification of tooth enamel; therefore, preventive measures should be taken.1,2

The potential value of antimicrobial agents in the control of plaque and gingivitis is well established. A number of antimicrobial agents have been studied and have shown varying degrees of antimicrobial activity,3,4 as well as the appearance of side-effects due to long-term use.5 JAL 90458 (the product under study) is a gel that reduces friction produced by the contact between the bracket and the archwire. Its ingredients include triclosan, zinc citrate and allantoine and can be an option to prevent these side-effects.6,7

Triclosan, one of the components of JAL 90458, has anti-plaque, anti-gingivitis and anti-calcification properties8-12 without local or systemic side-effects and it does not alter the oral microbial ecology.8 Zinc citrate improves the clinical efficacy of JAL 90458 by increasing substantivity of triclosan6,8,9 and allantoine regenerates gingival tissue.

The adequate formulation of these active ingredients in toothpaste and mouthwash, or other presentations such as sprays, oral strips, varnishes or gels, is extremely important to improve their effectiveness.2,8,13 As a gel, JAL 90458 allows for better adhesion to the tooth and soft tissue which increases its efficacy.

The composition of JAL 90458 allows it to be used as an aide to control plaque during orthodontic treatment with braces.

The main objective of this study was to assess the efficacy of JAL 90458 on plaque regrowth compared to a control gel. As far as we know, randomized clinical trials with triclosan in gel form have not been carried out on a sample population of this type. Secondary objectives included assessing the effect of JAL 90458 on the reduction of bleeding on probing and determining if there was a correlation between the Quigley – Hein plaque index, modified by Turesky (QHPI-T)14 and the Plaque – Bracket Index (PIb).15 If a high correlation (r>8) were to be found between the variables, a linear regression equation would be established. Another objective was to assess the frequency of the side-effects of each gel.

Material and Method

The study included 16 patients (11 women and 5 men) between the ages of 12 and 39 undergoing orthodontic treatment at the Orthodontics Department of the Instituto Europeo de Posgrado (IEP).

All of the patients were wearing orthodontic braces with brackets on incisors, canines and premolars and had Roth prescription .018" or .022" slot bands on the first molars for at least 6 months. The subjects were in good health with no history of medical conditions or medication that could compromise the results of the study. In addition to having good oral health, the subjects had at least 20 permanent teeth. Those patients were excluded if they had a history of multiple allergies, were pregnant or breastfeeding. Before starting, this study was approved by the Clinical Research Ethics Committee of San Carlos Clinical Hospital (CEHCSC) in Madrid.

The study was conducted under clinical trial conditions, double blind, parallel and randomized in balanced groups using a 4-day classic plaque regrowth design.16,17 The examination and selection of volunteers was done by only one especially trained examiner, who then proceeded to register the data in the Case Report Form (CRF). This examiner also registered all the visits in the trial. (Chart 1)

Before starting the experimental stage, the researcher assessed the medical condition of the subject. If the subjects fulfilled the selection criteria, they were told about the objectives of the study and were asked to volunteer to take part in the study. After signing the informed consent form, the subjects were included in the study. The researcher then assigned a code number to each subject, which was given according to the order in which they agreed to take part in the study. Each subject was also assigned the first free random number from the randomization list.

In visit 1 (Day 15), the subject received an examination of soft and hard tissues. The same dental hygienist cleaned their teeth and taught them the Bass Tooth Brushing Technique.18 They also received an oral hygiene kit which contained a standard toothbrush (Vitis® Access medium, DENTAID, Cerdanyola, Spain) and a conventional toothpaste (Colgate® Cavity Protection Toothpaste, Colgate-Palmolive Co., New York, United States). The subjects were instructed to brush their teeth thoroughly in the two weeks prior to the experimental stage and to not use any kind of mouthwash.

In visit 2 (Day 1), 15 days after visit 1, the selection criteria were confirmed by examining the patient's oral cavity and the Bleeding on Probing Index (BOP) was recorded. Their teeth were cleaned and they were given the assigned gel. The subjects were to follow their normal diet but the assigned gel was the only oral hygiene measure allowed during the experimental period. The subjects were instructed to apply the assigned gel on the vestibular and palatal/lingual gingival margin, as well as on the body and around the brackets, three times a day for four days following these indications: 3ml for 3 minutes after breakfast, lunch and dinner. Subjects had to wait at least 30 minutes after applying the assigned gel before eating.

In visit 3 (Day 5), after the last application of the gel in the morning, the last visit took place. After assessing the BOP, we calculated the QHPI-T and PIb. In order to assess the appearance of side-effects, the subjects were asked if they had had any tingling sensation, a change in perception of taste, a dry mouth and/or burning sensation. At the end of the study, following the oral exam, the patients had their teeth cleaned.

Chart 1. Outline of the clinical Trial.

The following formulations were used in the study: Experimental antifriction gel (JAL 90458) which contains triclosan (0.30g), zinc citrate (0.05g), allantoine (n/e) sodium fluoride (0.124 p/p) and the control gel (Pierrot® Fluoride Gel), which contains sodium monofluorophosphate (0.04p/p) and sodium fluoride (0.01p/p). These gels were distributed in identical syringes each stamped with a code. The subjects received twelve syringes each with 3ml of gel. In order to verify the degree of cooperation, each patient had to attend all of his/her visits. On Visit 3, the patient had to bring all the used syringes.

The plaque index was assessed on Day 5 according to the QHPI-T criteria.14 Six places around each tooth were recorded – mesiobuccal, medio-buccal, distobuccal, mesiolingual/palatal, medio-lingual/palatal and distolingual/palatal. The PIb was assessed on Day 5 on and around the brackets according to the criteria designed by Trimpeneers.15 The plaque score was done after the using pigmentation with Phloxine B (4%) (Plac Control®, DENTAID, Cerdanyola, Spain).

The BOP15 was assessed on Days 1 and 5 in the six places around each tooth. The probing was done with a UNC 15 periodontal probe (Hu-Friedy). When the probe could not be inserted along the long axis of the tooth, no score was given. This occurred mainly on the buccal surfaces where the brackets interfered with the probing.

Statistical Analysis

The data analysis was done using SPSS version 16. The data satisfied the criteria for normality.19 The average values of the clinical parameters were compared between the groups using a Student's t-test for independent samples.20 The level of significance was set at α = 0.05. The comparisons between the groups regarding side-effects were done using Fisher's exact test.21 Pearson's correlation coefficient between the QHPI-T and PIb was calculated. The high correlation (r>8) found between these variables allowed the linear regression equation to be established.22

Results

The study started with 18 patients. In the course of the study two patients were excluded because they did not go to their appointments. Of the remaining 16 patients, 5 were men and 11 were women. No significant differences were found between JAL 90458 and the control gel regarding the variables of age or sex.

All of the patients, both in the JAL 90458 group as well as in the control group, started with a QHPI-T equal to 0 before they were assigned the gel. Both groups increased their levels of plaque during the experimental period. The QHPI-T increase in the experimental group was less than in the control group. Statistically significant differences were found in favor of JAL 90458 (p<0.05). (Chart 2)

*: Statistically significant (p<0.05, Student's t-test)

The control group registered the highest PIb score. The differences between the two groups were statistically significant (p<0.05). (Chart 3)

*: Statistically significant (p<0.05, Student's t-test)

A high correlation was found between the QHPI-T and the PIb (r=0.94, p<0.01). This allowed us to establish the linear regression equation to predict the QHPI-T value from the PIb: QHPI-T = 0.568 + 0.956 * PIb. (Chart 4)

Dispersion Graph and Determination of the Linear Regression Equation.

We used the BOP to assess the gingival condition. The experimental group had the lowest BOP score. The differences found were statistically significant and favorable to JAL 90458. (Chart 5)

*: Non-significant (Student's t-test). Ɨ: Statistically significant ( p<0.001, Student's t-test)

Xerostomia was the most frequently described side effect, but these differences were not statistically significant between the groups.

Discussion

The accumulation of plaque in patients undergoing orthodontic treatment is common due to the difficulty of monitoring one's oral hygiene when the mouth is full of bands, arches, brackets and ligatures.23 Consequently, the mechanical control of plaque must be complemented with chemical control, professional cleaning and dietary advice.1,5

The results of this study show that JAL 90458 was significantly better than the control gel at controlling the regrowth of plaque. There are no other studies with which to compare these results.

There are a number of studies on the regrowth of plaque in patients which assess the efficacy of various mouthwashes, such as chlorhexidine,24,25,26,27 essential oils,4 benzamide hydrochloride – cetylpyridinium,28 cetylpyridinium,28,29 tin fluoride,24,29 polyhexamethlene biguanide,30 and the bisphenolic agent, triclosan. 4,24,25,26,27,32,31 The action of chlorhexidine according to these studies is better than the other agents, but its side effects, such as tooth stains and/or dysgeusia, have encouraged the development of alternative agents.9,10 Triclosan along with other substances that increase its substantivity, such as PVMMA or zinc citrate, have been shown to be effective in preventing the neoformation of bacterial plaque.9,16,32

There are other middle- and long-term studies on patients undergoing orthodontic treatment or not2,5,23 which analyze the use of different antiseptic agents23 in different formulations, such as mouthwashes5 and toothpastes,8,9,33,34 as aids to the mechanical procedures of oral hygiene. These studies have shown a significant reduction in the periodontal clinical parameters.

The PIb described by Trimpeneers15 was used to assess the efficacy of JAL 90458 against plaque on patients undergoing orthodontic treatment. As far as we know, there have been no other studies describing the regrowth of plaque that use this index and, therefore, we do not have anything to compare it to.

To determine if there was a linear association between the QHPI-T and PIb variables we used Pearson's correlation coefficient. A very high correlation coefficient was found. Therefore, we produced the linear regression equation to predict the QHPI-T from the PIb in case it was needed.

Supragingival plaque is a risk factor for the development of gingivitis. Since our study is on plaque regrowth, the direct effect of these agents on gingival tissue cannot be predicted. However, gingival health was determined using the BOP index. The results of this study show that JAL 90458 was significantly more effective than the control gel at lowering BOP; this was due to its anti-inflammatory34 and anti-microbial properties. 8,9,11

The side-effects described in this study were paresthesia, altering taste sensation, a burning sensation and xerostomia. No clinically relevant side-effects were found. The most common side effect was xerostomia, but no statistically significant differences between the two groups were found.

We are not aware of any previous studies on the possible long-term negative side effects of JAL 90458 on patients undergoing orthodontic treatment; however, it is one of the safest, best tolerated, effective chemotherapeutic agents available at this time.25,26,27,31,32,33,34

Conclusion

In conclusion, the topical application of JAL 90458 on patients with orthodontic braces was shown to be more effective on plaque regrowth than the control gel.

There was a significant reduction in the BOP index in favor of JAL 90458. Furthermore, we found a high correlation between the QHPI-T and the PIb. The regression equation to predict the value of QHPI-T from the PIb was as follows: QHPI-T = 0.568 + 0.956 * PIb.

A low incidence of side-effects was found. Xerostomia was the most common side-effect in both groups but there were no statistically significant differences between the two groups. More clinical trials are needed to confirm these results.