Comparison of two commercial dentifrices in the reduction of gingivitis and plaque : A pilot study

Objetivos: Clorexidina e triclosan são os agentes químicos mais utilizados em odontologia. No entanto, a combinação desses produtos nunca foi testada. Nós levantamos a hipótese de que a adição de clorexidina a um dentifrício contendo triclosan pode oferecer benefícios adicionais na redução de placa e gengivite. Assim, o objetivo deste estudo foi comparar um dentífrico comercial contendo 0,05% de clorhexidina e 0,3% de triclosan, com creme dental convencional contendo 0,3% de triclosan, no tratamento de gengivite e redução da placa. Material e Métodos: trinta voluntários foram distribuídos aleatoriamente para receber um dentifrício contendo 0,05% de clorexidina e 0,3% de triclosan ou um dentifrício contendo basicamente 0,3% de triclosan. Os indivíduos receberam avaliação clínica de índice gengival (IG) e índice de placa (IP) nos tempos 0, 30 e 60 dias. Resultados: após 60 dias, ambos os tratamentos levaram a uma melhora significativa no IG e IP. Não houve diferença significativa entre os grupos no que se refere à mudança no IG e IP (p> 0,05). Conclusão: A combinação de 0,05% de Clorexidina com 0,3% de triclosan não ofereceu benefícios adicionais para a redução de inflamação gengival e o controle da placa quando comparado com um dentifrício contendo 0,3% de triclosan. ABsTRACT


INTRoDuCTIoN
G ingivitis is characterized by a reversible periodontal inflammation associated with biofilm [1].Epidemiological studies have shown a high prevalence of this condition, involving over half of the US population [2].Daily mechanical control by tooth brushing and dental flossing has been shown to be effective in the treatment and prevention of gingivitis.However, achieving an adequate plaque control is difficult for most people [3].Mechanical control alone reduces dental plaque to 30-50% only [4].The result is a high prevalence of dental plaque, dental calculus and gingival bleeding, as shown in epidemiological studies [5].In this context, the development of new and diverse dentifrice compositions is important in order to optimize the effectiveness of plaque control.Several agents have been studied for their plaque-inhibitory action such as triclosan, sodium fluoride and chlorhexidine [3,4,6,7].
Chlorhexidine (CHX) is an antiseptic with a broad antimicrobial action, including a wide range of Gram-positive and Gram-negative bacteria.Its dental plaque inhibition properties were first investigated by Schroeder [8], and it was confirmed as later by as an effective agent in preventing gingival inflammation and reduction of plaque by Löe and Schiott [9].Since then, it has played a central role in research, being used in many vehicles such as gels, varnishes, chips, chewing gums, dentifrices and mouthwashes [10][11][12].In dental practice, mouthwash is the most used form, though clinical studies has shown that CHX in dentifrices can also offer further benefits to oral health with less tooth discoloration [13].Moreover, a meta-analysis performed in 2014 showed that CHX dentifrices provide a significant benefit on the treatment of gingivitis and plaque inhibition [14].Besides that, when used for long periods, CHX has shown to produce local side effects such as tooth staining and taste disturbance [15,16].
The addition of CHX to a triclosan dentifrice formulation may offer additional benefits in the reduction of plaque and gingivitis.However, so far, no study has compared the combination of these two substances with a triclosan dentifrice.
Thus, the aim of this randomized clinical trial was to compare a commercial dentifrice containing chlorhexidine plus triclosan with a conventional toothpaste containing triclosan, in the treatment of gingivitis and plaque reduction.

Trial Design and participants
This was a randomized, double-blind, two-arm parallel-group controlled trial.Participants were selected among those seeking dental treatment at UNESP -São Paulo State University (São José dos Campos, Brazil).The inclusion criteria were: 1. Patients with at least twenty-four teeth in mouth, 2. 18-35 years old.Exclusion criteria were: 1. smoking, 2. Presence of braces or other orthodontic appliances, 3. use of antibiotics 6 months prior to the study and 4. Patients with periodontitis, oral cancers and caries lesions.
All subjects received intraoral examination and answered a questionnaire comprising questions regarding medical and dental history.The subjects who fulfilled the inclusion criteria were invited to participate in the study.All individuals who agreed to participate were informed about the nature, potential risks and benefits of the study and signed a term of free informed consent.The study was approved by the Ethics Committee of UNESP-Institute of Science and Technology, under the protocol 41294914.7.0000.0077.

Interventions and procedures
One of the investigators (W.D.K.) was responsible for participant's enrollment and assignment to interventions.The study coordinator (E.S.R) used a computer-generated sequence to randomly assign the subjects to the following two groups: i) CHX/triclosan: Dentifrice produced by Pharmakin, containing chlorhexidine digluconate 0,05%, triclosan 0.30 %, zinc lactate 0.50 % and sodium Fluoride ppm and ii) Triclosan: (sodium Fluoride 1450 ppm, Triclosan 0,3% and copolymer (Colgate Total 12®, Colgate Palmolive Co.).Both dentifrices were packaged into identical tubes containing the number to which the participants were assigned.
Initially, all subjects received prophylaxis oral hygiene instructions.The subjects were instructed to use the same toothbrush, dental floss (Kinextra soft, Espanha) and not to use any oral antiseptic solution during the study period.Moreover, the subjects were instructed to use the same amount of the assigned dentifrice during the toothbrushing, which was performed during two minutes, three times a day, during the study period.

Outcomes and blinding
The primary outcome variable was mean GI reduction (baseline -60 days).Secondary outcome variables were mean PI and tooth staining after 60 days and PI reduction (baseline -60 days).
The following clinical parameters were evaluated at baseline, 30 and 60 days: Gingival index (GI) [25], Plaque index (PI) [26] and Tooth staining (absent/present).Further, the subjects were asked about any adverse effect of the toothpaste during the study.
A single examiner (HVB) performed all clinical examinations.The examiner did not know which dentifrice each participant received.Participants and personnel providing treatment were not aware about the content of their assigned dentifrice.

Statistical analyses
Mean clinical parameters were computed for each subject and then for each group.Intragroup and intergroup mean differences in GI and PI were evaluated by ANOVA.Student's T-test was used to compare intergroup mean difference as regards age.Fisher´s exact test was used to evaluate association between group and tooth staining or gender.

Subject retention, compliance and adverse effects
Thirty subjects were selected for the study.All participants remained until the end of the follow-up period.Flow chart of the study design is presented in Figure 1.Table 1 depicts clinical and demographic information of the patients.No significant differences were found between the two groups as regards age, gender and baseline clinical parameters (p>0.05).All subjects reported having followed the instructions during the 60 days of the study.
Two individuals from the CHX/triclosan group presented tooth discoloration.The other subjects did not report any side effects associated with the substances used.
Braz Dent Sci 2017 Oct/Dec;20(4)  The significant difference between baseline, 30 and 60 days was assessed using repeated ANOVA and Student t-test.Fisher's T-test was used for categorical variables.
The significance of differences between baseline, 30 and 60 days was * Indicate significant differences between time points.

Clinical outcomes
No statistically significant differences were observed between groups for age, gender, GI, PI and tooth discoloration at baseline, 30 and 60 days (p > 0.05).After 60 days, both treatments led to a significant improvement in GI and PI.
Table 2 shows the changes in mean GI and PI between baseline and 60 days.There was no difference between groups as regards change in GI and PI.

DIsCussIoN
The results of this randomized clinical trial showed that both dentifrices led to a significant improvement in clinical parameters, although no significant difference between the two groups were found.After 60 days, the clinical improvements observed in both groups were more compatible with studies that investigated the effect of a daily toothbrushing with a triclosan dentifrice [23,28,29] than studies with CHX [30][31][32].In this study, the incorporation of 0.05% chlorhexidine in a dentifrice containing 0.3% triclosan (CHX/triclosan group) did not offer further benefits to gingival inflammation and plaque control in comparison with a dentifrice containing 0.3% triclosan (Triclosan group).
The GI reduction of 0.25 and 0.22 observed in the CHX/triclosan and Triclosan groups, respectively, are in agreement with other trials which assessed the effects of a dentifrice containing triclosan in these clinical parameters [27][28][29].Moreover, in a metaanalysis performed by Hioe & van der Weijden [23], the authors found an IG reduction of 0.24 and 0.48 in PI, favoring triclosan.The results of this meta-analysis are similar to those of the present study.
CHX is the most effective anti-plaque and anti-gingivitis chemical agent in dentistry [14].When associated to dentifrices, it has been successfully tested and used in order to enhance mechanical plaque control [14].However, in this present trial, the association of 0.05% CHX with 0.3% triclosan did not result in additional benefits to gingival inflammation and plaque control in comparison with a dentifrice containing 0.3% triclosan.
An important issue to be considered is the low-dose 0.05% CHX used in the CHX/triclosan group.The dose-dependent anti-plaque effects of CHX have been shown in vivo studies [33].Hoffmann [34] assessed the clinical effects of rinsing with a low-dose 0.06% CHX in comparison with a commercially available 0.1% CHX.At the end of the trial, the authors suggested a minimum concentration of 0.1% CHX if a further decrease in GI is desired.Furthermore, there are no comparative studies regarding the triclosan when associated with other substances such as CHX, in gingival parameters.Thus, there is no evidence that this association might enhance the anti-gingivitis and anti-plaque effect.Mendes [35] assessed the effects of rinsing 0.05% chlorhexidine, 0.15% triclosan and 0.18% zinc pidolate on bad breath.At the end of the study, authors demonstrated a significant effect on this outcome, however, no major comparisons can be made since the vehicle and outcome assessed were different from the present study.
When CHX is used for long periods, tooth discoloration is the side effect most expected.At 60 days, only two individuals from the CHX/ triclosan group presented tooth staining.This fact might be explained by the low-dose 0.05% CHX used in the CHX/triclosan group.Moreover, there is evidence that the dose-dependent antiplaque effect can be applicable in regards to tooth discoloration [14,36].Therefore, a slight tooth staining was expected in this study.
Since this trial has limitations, the results of the present study might be interpreted with caution.An important issue that must be considered is that the GI and PI of the subjects at baseline were low, which may not represent the majority of the population.In addition, the short-term follow-up period of 60 days and the small sample size (n=15) might have interfered in the results.Thus, the results presented here suggests that the combination of 0.05% CHX with 0.3% triclosan did not offer further benefits to gingivitis reduction and plaque control when compared with a dentifrice containing 0.3% triclosan.Nevertheless, more studies are needed to corroborate these findings.

CoNClusIoN
The combination of 0.05% CHX with 0.3% triclosan did not offer further benefits to gingival inflammation and plaque control when compared with a dentifrice containing 0.3% triclosan.

Figure 1 -
Figure 1 -Flow chart of the study design.

Table 1 -
Demographic characteristics and mean ± SD clinical parameters at baseline, 30 and

Table 2 -
Mean and SD GI and PI reduction between baseline and 60days.