INTRODUCTION

The placement of fixed orthodontic appliances generally hinders good oral hygiene, and the appliance components can cause alterations in the oral microflora by reducing pH, increasing affinity of bacteria to the metallic surface because of electrostatic reactions, and causing retention areas for microorganisms. Thus, they lead to plaque accumulation around the bracket base.1–3

Increased levels of Streptococcus mutans and Lactobacillus species have been reported to be detected in the oral cavity after bonding orthodontic attachments, and several studies have reported that there is a positive correlation between dental caries and the degree of infection with S mutans and lactobacilli.4–6 These microorganisms are known to cause alterations in its microenvironment that can be responsible for the enamel decalcification and smooth surface caries during orthodontic treatment.7 An increase in the S mutans level will also result in an imbalance between demineralization and remineralization of dental hard tissue, which leads to the acute inflammation of gingiva,8 so the reduction of cariogenic bacteria from the oral cavity is a crucial step for the prevention and treatment of caries during orthodontic treatment.

Practicing satisfactory oral hygiene, such as adequate tooth brushing, mouth rinsing, gum chewing, dental flossing, and using sustained-release varnishes, plays a vital role in maintaining healthy teeth throughout orthodontic treatment.9–11 The effective control of dental plaque and thereby of dental diseases of microbial etiology by mechanical means is dependent on patient compliance and appears to be limited to the failure of the patient to reach certain plaque-infected sites that are hindered by the brackets and wires. Hence, a great need arises for the development of antibacterial and antiadhesive chemotherapeutic agents to assist in the control of infections associated with dental plaque.

Octenidine dihydrochloride (OCT) has been shown to be effective in controlling bacterial plaque formation.1213 In the study of Rosin et al,14 the plaque regrowth and bacterial counts were evaluated at the end of the fifth day. The antibacterial and antiplaque effect of polyhexamethylene biguanide hydrochloride, chlorhexidine gluconate (CHX), and Listerine mouth rinses were evaluated after the tooth cleaning was ceased.14 They reported that while the reduction of bacterial growth on teeth surfaces with 0.12% biguanide hydrochloride was significantly greater compared with the placebo or Listerine, chlorhexidine was more effective than biguanide hydrochloride after 5 days. In addition, chlorhexidine was significantly more effective in reducing bacterial counts on mucosa than biguanidine and Listerine after 5 days. Arweiler et al15 assessed the bacterial vitality between 24 and 96 hours for two commercial 0.2% chlorhexidine solutions and compared them with a negative control. The results after 96 hours suggested that 0.2% alcohol-containing solution showed superiority in inhibiting plaque regrowth and reducing bacterial vitality compared with the solution with antidiscoloration system.

In our previously published study, we detected the MIC activities of OCT, polyvinylpyrrolidone-iodine complex (PVP-I), and CHX for S mutans and Lactobacillus species. Our results yielded that OCT had a significantly greater inhibitory effect on the studied bacteria than 0.2% CHX and 7.5% PVP-I from 15 minutes to 120 minutes following the application (P < .01).16 In the present study, we aimed to determine the reduction effects of these mouth rinses, during their 5 days of usage time, on the cariogenic bacteria that cause acute gingivitis, smooth surface caries, and white spot lesions during orthodontic treatment, which leads to tooth and periodontal damage at the end of the treatment.

MATERIALS AND METHODS

The study group consisted of 18 patients (5 male, 13 female; 12 to 16 years old) selected from patients assigned for orthodontic treatment at the Department of Orthodontics, Süleyman Demirel University, Isparta, Turkey. The research project was approved by the Local Ethics Committee of Medical Faculty of Süleyman Demirel University. Written informed consent was obtained from each subject on a voluntary basis, with the option that the participants could withdraw for any reason at any time. All subjects were selected from the individuals who had good oral hygiene and whose plaque and bleeding scores were not different in the beginning (Table 1). All patients underwent full-bonded edgewise treatment with metal brackets on their anterior teeth and premolars and bands on their molars. None of the subjects received antibiotics or topical antiseptics during the previous 30 days or had systemic disease which would have altered the amount or composition of the plaque or saliva. There was no known hypersensitivity to any of the used mouth-rinsing antibacterial solutions.

Table 1.  Plaque and Bleeding İndex Results Before Saliva Collec tion

View Fullscreen

The study began the day after bonding the brackets and bands and lasted 2 months by 2-week intervals. The experiment was done on the same patient for each mouth rinse solution separated by 2 consecutive two week intervals. Measures of plaque and papilla bleeding indexes were determined according to Sillness and Löe17 at the beginning of each phase. The plaque and bleeding scores of all subjects were brought to zero with a thorough dental prophylaxis at baseline for each mouth-rinsing solution. Thus, a week interval was given to each patient for dental prophylaxis until the trial of the next mouth-rinsing solution. The solutions used for the experiments were OCT (Octenisept, Schülke & Mayr GmbH, Norderstedt, Germany), 0.2% CHX (Klorhex, Drogsan, Ankara, Turkey), 7.5% PVP-I (Batticon, Adeka, Samsun, Turkey), and physiologic saline (PS).

The volunteers were asked to collect 2–3 mL of unstimulated saliva in the morning as a baseline sample and at 15 minutes after swishing the mouth. They were also instructed to use 15 mL of the mouth rinse for 30 seconds once a day each morning for 5 days. The saliva collection was repeated on the second, third, and fifth day. The volunteers were asked to brush their teeth after dinner without toothpaste the day before sample collection and refrain from eating in the morning and brushing during the course of the experiment until the end of the fifth day. They were asked not to have breakfast before giving saliva each morning. All samples were carried to the Microbiology Laboratory of the Medical Faculty under sterile conditions in half an hour's time and stored at +4°C until they were processed on the same day. Mitis Salivarius agar (Difco Laboratories, Sparks, Md) supplemented with 15% sucrose and bacitracin (0.2 U per mL of medium) for S mutans, and Rogosa agar (Oxoid, Basingstoke, Hampshire, England) for Lactobacillus species were used as selective mediums. Total viable counts of all cultivable facultative anaerobic bacteria were incubated onto Trypticase soy agar enriched with 5% (v/v) sheep blood. Microbiologic procedures were established according to Dogan et al.16 Results were presented as colony-forming units (CFU)/mL.

RESULTS

The minimum, maximum, and median CFU of total bacteria, Lactobacillus species and S mutans in the saliva of subjects before mouth rinsing (T0), on 15 minutes after swishing the mouth, and on the second, third, and fifth days during treatment with antiseptics are presented in Table 2. OCT had a significantly stronger impact on the microbial burden of the oral cavity than the other mouth-rinsing solutions from the beginning of the study until the fifth day (P < .01). The antiseptic efficacy of CHX 0.2% on S mutans, Lactobacillus species, and total flora was very similar to the efficacy observed with 7.5% PVP-I mouth solution from the beginning of the antiseptic treatment until the fifth day (Table 2).

Table 2.  The Minimum, Maximum, and Median CFU (log10) of Total Bacteria, Lactobacillus Species and Streptoccocus mutans in the Saliva of Subjects During Treatment With Different Antiseptics

View Fullscreen

CFU-time graphics of total bacteria, Lactobacillus species, and S mutans are presented in Figures 1, 2, and 3. Bacterial count changes detected with different mouth rinses for each time period are presented in Table 3. In addition, a comparison of the antibacterial effect of different mouth rinse solutions for each time is given in Table 4. There was no significant difference between bacterial counts detected in the saliva of subjects before mouth rinsing. We have not detected significant difference between antibacterial effects of CHX and PVP-I for any time period. On the other hand, OCT displayed significantly more antibacterial effect on all time periods except for time period T1 for S mutans.

View Figure

• Download as Powerpoint
• Download Figure

View Figure

• Download as Powerpoint
• Download Figure

View Figure

• Download as Powerpoint
• Download Figure

Table 3.  Bacterial Count Changes Detected With Different Mouth Rinses^a for Each Time Period*

View Fullscreen

Table 4.  Comparison of the Antibacterial Effect of Different Mouth Rinse Solutions for Each Time Period^a

View Fullscreen

DISCUSSION

The accumulation of supragingival dental plaque on tooth surfaces is the major etiological component in the development of caries and periodontal disease. Numerous reports have documented that the flora change from primarily Gram-positive to Gram-negative bacteria in conditions leading to gingivitis.1819 When mechanical plaque control is hampered, the chemical procedure remains the next best choice. Even though several other studies have tested the effects of CHX20–22 and PVP-I,23 there are only a few studies that tested OCT24–28 to evaluate its contribution to oral hygiene by determining its effects on the number of total and cariogenic bacteria during its usage time.

In this study, S mutans was reduced significantly with CHX (P < .05) on T1 and T2 time periods and began to increase on time period T3. Significant reduction in S mutans levels was similar to the results of studies in which CHX varnish1029–32 and mouth rinse20–23 were used, but the increase in S mutans count on the third day opens the lasting antibacterial effect of CHX to debate.

Decker et al33 reported that among all antiseptic formulations (Olaflur, CHX) the application of OCT had the strongest impact in terms of lethal effect on the attached bacteria. In particular, the drastic log₁₀ reduction of CFU values in the range of 8 belonging to the antibacterial effect of OCT resembles the findings of our previous study.16 In our study, OCT was found to be efficacious and compared favorably with CHX and PVP-I in its antibacterial effect in saliva. This effect was seen on the third and fifth days as well. These results were also consistent with those of Kramer et al28 who reported that OCT and cetylpyridinium chloride were significantly more effective than other mouth-rinsing solutions including Corsodyl (which contains chlorhexidine gluconate) in their immediate value. These researchers reported that the only drawback of OCT use was its bitter taste. Beiswanger et al13 also have reported that the group rinsing with 0.1% OCT, had significantly lower levels of plaque, less gingivitis, and fewer bleeding sites when compared with the control group.

Slee and O'Connor34 found comparably favorable effects of OCT compared with CHX on S mutans, Streptococcus sanguis, Actinomyces viscosus, and Actinomyces naeslundii with respect to overall antiplaque potency in vitro, whereas Samet et al35 found that the kinetics of OCT in killing Staphylococcus aureus depended on its concentration but was independent of bacterial genotype. Sedlock and Bailey36 also established the therapeutic superiority of this antiseptic agent to CHX. In the 4-week follow-up study of Sari and Birinci,22 it was reported that S mutans and lactobacilli levels increased significantly after bonding the fixed appliances; however, even a low concentration of 0.2% CHX mouth rinse significantly reduced S mutans levels. They suggested that 0.2% CHX mouth rinse could successfully be used to decrease S mutans levels in combination with tooth brushing and flossing. In our study, we evaluated the antibacterial effect of CHX according to Rosin et al14 and Arweiler et al15 without tooth brushing and determined that OCT was found to be efficacious and compared favorably with CHX and PVP-I in its antibacterial effect in saliva during the 5 days of usage. Lactobacillus species decreased significantly by the usage of the three different antibacterial mouth-rinsing solutions. S mutans levels were significantly decreased by OCT and PVP-I until the fifth day but began to increase during CHX usage in the third day. Thus, we can suggest that while OCT can be selected alone for the immediate eradication of acute gingival inflammation, CHX might be more efficient in combination with mechanical plaque removal, such as tooth brushing, in controlling chronic inflammation related to the increment of S mutans and lactobacilli levels in orthodontically treated patients with fixed appliances, and for the prevention of enamel decalcification and white spot lesions.

CONCLUSIONS

• During 5 days of usage, OCT was the most effective mouth rinse among the tested rinses as evidenced by a substantial reduction of total salivary and cariogenic bacterial counts (P < .01).

• Although we can suggest that patients can use OCT mouth rinse once a day during orthodontic treatment, recommendation of OCT for long-term use in orthodontic patients is not justified because some unanswered questions still remain.