Comparative Evaluation of 0.1% Octenidine Mouthwash with 0.2% Chlorhexidine Mouthwash in Prevention of Plaque and Gingivitis –A Clinicomicrobiological Study

Introduction

Plaque is found to be the primary etiological agent in gingival inflammation and has also been associated with the initiation and progression of periodontal diseases. The amount of plaque has been directly linked to the severity of gingival inflammation. The mainstay of primary and secondary prevention of periodontal diseases is to control dental plaque.^1,2

Mechanical means like tooth brushing and interdental cleaning aids are primary in plaque control. But it is often poorly carried out by most individuals as its effectiveness mainly depends on the technique and skill of the individual. When mechanical plaque control is compromised, then chemical procedure remains the next best choice. Hence, mouthwashes could be a valuable component of oral hygiene regimens.^3-5

There are vast varieties of antiseptic mouthrinses available in the market but the most effective and preferred anti-plaque agent till today is chlorhexidine gluconate.⁶ However, it has side effects like unpleasant taste, hypogeusia, tooth staining and mucosal erosions etc.^7,8 Hence, there is a need for newer alternative agents to overcome these disadvantages.

Octenidine hydrochloride (OCT), a bispyridinamine is one such novel agent that was developed in the 1980s. Since 1995, it has been licensed as an antiseptic agent in 20 European countries. Octenidine dihydrochloride is an antiseptic with two active cation centers in its molecule which do not interact with each other as a long aliphatic hydrocarbon chain separates them. This makes octenidine toxicologically safe as 4-chloraniline cannot be liberated.^9-12

Due to prolonged bacterial anti-adhesive activity, OCT appears to be more effective than chlorhexidine (CHX). There is also data showing the beneficial effects of mouth rinse containing 0.1% OCT against plaque accumulation and gingivitis.¹³

Most importantly, OCT has a high affinity for cardiolipin which is specific to bacterial cell membranes, which makes it lethal only to bacterial cells and not to human tissue and epithelium.¹⁴

Regardless of these beneficial effects, still the literature regarding the use of Octenidine as a mouthwash on plaque control is found to be very limited. Hence, this clinicomicrobiological study was undertaken to evaluate the effects of 0.1% Octenidine mouthwash compared to 0.2% chlorhexidine mouthwash in the prevention of plaque and gingivitis.

Materials and Methods

Study population

A total of 69 subjects of both the sexes visiting the Outpatient Department of Periodontics were considered for the study. The study was conducted from April 2019 to November 2019. The research protocol was reviewed and approved by the Institutional Ethical Committee. (IEC 97/2019)

Eligibility criteria

Inclusion criteria: Subjects aged between 20-50 years, with moderate to severe gingivitis and having at least 20 erupted teeth.

Exclusion criteria: Subjects with history of any systemic diseases, pregnant and lactating females, history of any antiseptics and antibiotic therapy in the past three months, history of oral prophylaxis in the past six months, subjects using orthodontic and prosthodontics appliances, subjects with mouth breathing habits, subjects with harmful habits like tobacco chewing, smoking, and alcohol consumption.

Clinical diagnostic procedure and informed consent

A detailed medical and dental history was recorded using a case chart. An informed consent was obtained from each patient prior to the treatment procedure, explaining intended treatment, the possible outcomes, complications and follow-up period needed.

Randomization and blinding

Sample size calculation considering 20.4% prevelence of chronic gingivitis in Karnataka with 80% power was done and the required sample size was calculated with the formulaN

= Z2 *P (1-P)/d2

Considering 10% attrition rate, total sample size considered was 68. Since the study has three groups, sample size was calculated with 23 subjects in each group.

Subjects were randomly assigned (Lottery method) into one of the three groups:

Group A- Scaling

Group B - Scaling + 0.2% chlorhexidine (HEXIDINE mouthwash, ICPA)

Group C- Scaling + 0.1% Octenidine (Orahex Pro mouthwash, Abbott Healthcare Pvt. Ltd, Thane, India.)

Blinding

The mouthwashes were dispensed in similar clear bottles. The investigator performing the clinical examination and the study participants were blinded to the treatment allocation.

Clinical periodontal assessments

At baseline, subjects were assessed for plaque and gingival inflammation by recording Plaque index (Turesky-Gilmore-Glickman modification of the Quigley Hein, 1970) and Gingival index (Loe And Silness 1963).

Treatment procedure

After removing the supragingival plaque, the area was isolated and subgingival plaque samples were taken using sterile Gracey curette (Hu-Friedy’s). The pooled samples for each patient was sent for microbiological analysis. Following this, thorough scaling was carried out for all the selected study subjects. In addition to scaling, subjects in Group B (0.2% CHX), and Group C (0.1% OCT) were assigned to use respective mouthwash for a period of 21days. Subjects were instructed to rinse with 10 ml of mouthwash for 1 minute twice daily, 30 minutes after brushing. All the participants were instructed to follow Modified Bass method of brushing and were provided with a uniform brand of toothpaste and brush.

Parameters were recorded for plaque, gingival index and total anaerobic colony count was calculated at baseline, on 14th day, and 21st day. Subjective and objective criteria were assessed on the 14th day and 21st day. 15 The subjective criteria and the objective criteria recorded were as follows:

Subjective criteria:(i) Taste acceptability: 0- acceptable; 1- unacceptable; (ii) Burning sensation: 0 – absent; 1- present; (iii) Dryness/Soreness: 0- absent; 1- present.

Objective criteria: (i) Ulcer formation: 0- absent; 1- present; (ii) Staining of teeth: 0- absent; 1- present; (iii) Allergy: 0- absent; 1- present.

Microbiological evaluation

Immediately upon obtaining the plaque sample, it was transferred to Robertson cooked meat medium. Subsequently, it was sealed with a cotton plug followed by labelling with a unique number for each sample. Samples were cultured within 24 hours after sample collection. After vortexing the samples, 10µl of the sample was streaked into blood agar and incubated in an anaerobic cabinet at 37°C for 72 hours. After 72 hours, the culture plates were removed and examined for the presence of colonies. The colonies were subsequently counted and expressed as colony-forming units per millilitre (CFUs/mL).

Statistical analysis

Statistical analysis was performed using R software program version 3.6. ANOVA was used to compare the parameters of more than two groups. Parameters between two groups were compared using ‘t’ test and within the group comparisons were made using repeated measures of ANOVA. Statistical significance was set at a p value of < 0.05.

Results

A total of 69 subjects were assessed for statistical evaluation for this clinicomicrobiological study with 23 subjects in each group.

All the parameters significantly decreased (p<0.05) from baseline to 21 days in all the three groups. The mean difference between the groups from baseline to 21st day were statistically highly significant (p<0.00001). Among the groups, Octenidine (OCT) group showed better results. The highest percentage change in all the parameters at 21st day was also noticed in subjects using 0.1% OCT. (Table 1 & Table 2; Figure 1 & Figure 2). Bacterial colony forming units (CFU/mL) on culture media reduced from baseline to 21st day, among all the three groups (Figure 3).

On comparison between scaling and subjects using different mouthwashes, scaling reduced plaque and improved gingival status, but greater improvement in parameters was observed with adjunctive use of chlorhexidine mouthwash or Octenidine mouthwash and the difference was statistically significant (p<0.05) at 21st day of evaluation period. (Table 3 & Table 4)

On comparison between group B (0.2% CHX) and group C (0.1% OCT), although better mean reduction in all the parameters was seen for Group C (0.1% OCT mouthwash), except the plaque index (p<0.05), none of the other parameters between Group B (0.2% CHX mouthwash) and Group C (0.1% OCT mouthwash) showed statistically significant difference (Table 5).

Mean ± SD- Mean± Standard deviation, * statistically significant p<0.05, * highly significant- p< 0 .00001 Subjective findings and objective findings Based on the observations made from subjective and objective criteria, (Table 6, Table 7) Octenidine mouthwash was better acceptable in taste compared to chlorhexidine mouthwash and had no noticeable side effects other than mild staining. All the subjects using 0.2% CHX mouthwash reported staining. No other side effects were noticed for either of the mouthwashes.

Discussion

The present study aimed to compare the efficacy of mouthwash containing 0.1% Octenidine with the gold standard 0.2% chlorhexidine mouthwash. Octenidine dihydrochloride is a positively charged compound that exerts its antibactericidal action by binding to the negatively charged bacterial cell membranes, as well as to all the soft and hard tissue surfaces of the oral cavity. It has both lipophilic and hydrophilic properties, allowing it to be embedded in the phospholipid bilayer, disrupting the regular distribution of phospholipids and attacking the enzyme systems, resulting in damage to the cell wall and leakage of cytoplasmic contents with disruption of the mitochondrial function. It shows a broad antimicrobial activity against Gram-positive and Gram-negative bacteria, chlamydiae, and fungi, which is mainly concentration and time dependent.^14,16 Despite these advantages, the literature regarding Octenidine mouthwash was found to be lacking. To the best of our knowledge, no studies have been carried out, comparing the clinical and microbiological effectiveness of Octenidine mouthwash to chlorhexidine mouthwash in chronic gingivitis patients.

A concentration of 0.1% Octenidine was selected for the present study as this was found to be the most effective concentration in reducing salivary bacterial count with minimal side effects.¹⁷

The results of the present study did not show significant differences in any of the parameters between the groups at baseline, but there was a statistically significant decrease (p<0.05) in plaque index, gingival index and total anaerobic bacterial count from baseline to 21^st day between the groups. Among all the groups, subjects using 0.1% OCT mouthwash showed the highest reduction in all the measured parameters at 21^st day, i.e., mean plaque reduction of 87.45% and 98.18% reduction of gingival inflammation when compared to 0.2% chlorhexidine and scaling.

The results of the present study are in accordance with the findings of previous study where rinsing with 0.1% Octenidine showed reduced plaque, gingivitis and bleeding sites compared to the control group.¹⁸ Similarly, several other studies have also reported favourable results with Octenidine mouth rinse compared to chlorhexidine in reducing dental plaque and gingival inflammation.^5,13,19 Sedlock and Bailey also established the therapeutic superiority of Octenidine over chlorhexidine.²⁰

In the present study, Octenidine showed excellent antibacterial activity as it significantly (p<0.05) reduced the mean anaerobic bacterial count from 5.88±0.42 CFU/mL at baseline to 4.25±0.37 CFU/mL at the end of 21 days. OCT mouthwash (0.1%) was also more effective in reducing plaque compared to 0.2% CHX mouthwash. These results may be due to a more persistent antimicrobial effect of Octenidine compared to chlorhexidine. ²¹

In present study, although 0.1% Octenidine mouthwash was found to be more effective in reducing plaque, gingival inflammation and total bacterial count when compared to the other two groups, except for significant reduction in plaque, there was no statistically significant difference between 0.1% Octenidine mouthwash and 0.2% chlorhexidine mouthwash (p>0.05) for other tested parameters at any given point of time. This result is consistent with that reported by Welk A et al. which showed comparable antibacterial efficacy of 0.1% Octenidine to that of 0.12% chlorhexidine.²²

Mouthwashes have shown to reduce plaque biofilm and also have a breath-freshening effect.²³ In the present study, it was noteworthy that the adjunctive use of mouthwashes after scaling had a beneficial effect on all the tested parameters when compared to subjects in the control group who received only scaling.

The compliance of any medications by patients largely depends upon their taste, colour, odour and appearance.²⁴ The major drawback with many of the commonly available mouthwashes is their staining, unpleasant taste and hypogeusia. Hence in the present study, an effort was made to assess these effects by the subjective and objective changes over a period of 14 days and 21days. On evaluation, it has been observed that the taste of OCT was more appealing to subjects initially as compared to CHX mouthwash. However, prolonged sensation post rinsing was reported by subjects in both the groups and was more pronounced in subjects using 0.1% CHX mouthwash. Previous data also reported an appealing taste with OCT mouthwash similar to that found in our study.²⁴

Hypogeusia with chlorhexidine mouthwash is very well documented,8 but to our surprise subjects using Octenidine mouthwash also reported transient hypogeusia lasting for few hours after its initial use. Consistent with the previous literature,²⁵ staining of teeth was observed in all the subjects of our study on using chlorhexidine mouthwash. Surprisingly, few subjects using 0.1% OCT also exhibited mild staining at 21 days of evaluation period. These side effects of Octenidine may be attributed to its longer adhesion to tooth surface and more persistent duration of action.^13,21

The results of the present study suggest pronounced and persistent antibacterial properties of Octenidine for controlling plaque and gingivitis. Therefore, Octenidine mouthwash could certainly be a promising candidate in oral antiseptic therapy.

However, in our study 0.1% OCT mouthwash could have been compared with 0.12% chlorhexidine mouthwash for more accurate results. Another important limitation was the shorter duration of the study and narrow assessment scale used for testing the subjective and objective criteria.

Moreover, a crossover design with a wash off period would have been more favourable in ascertaining the obtained results.

Conclusion

Based on the findings of the present study, it can be validated that mouthwashes when used as an adjunctive to scaling have positive benefits in patients with severe gingivitis. Although mouthwash formulation containing 0.1% OCT had some milder side effects, it had pronounced effect in reducing plaque and gingivitis compared to 0.2% CHX. Hence, it can be a promising alternative to chlorhexidine mouthwash in prevention of plaque and gingivitis.

But more long term randomised trials must be undertaken in future to confirm Octenidine’s relative safety, biocompatibility and absence of unfavourable cosmetic and organoleptic properties.

Footnotes

†Orahex Pro mouthwash, Abbott Healthcare Pvt.Ltd, Thane, India.

Conflict of Interest

None.