The effect of mouthrinses containing zinc and triclosan on plaque accumulation and development of gingivitis in a 3-week clinical test

Incorporation of zinc into cetylpyridinium chloride mouthwash affects the composition of multispecies biofilms

This study evaluated the effect of a mouthwash containing 0.075% cetylpyridinium chloride and 0.28% zinc lactate (CPC + Zn) in a multispecies biofilm model. A 7-days 33-species biofilm, formed on Calgary device, was 1-min treated with: 0.12% chlorhexidine (CHX), culture medium (negative control), 0.075% cetylpyridinium chloride (CPC) or CPC + Zn, 2x/day, from day 3 until day 6. The metabolic activity and the microbial composition were evaluated by colorimetric method and checkerboard DNA-DNA hybridization, respectively. The three antimicrobials (CPC, CPC + Zn and CHX) reduced metabolic activity, total biofilm count and several species counts, including Porphyromonas gingivalis, Fusobacterium nucleatum, Parvimonas micra, Campylobacter gracilis and Streptococcus mutans. However, only CPC + Zn reduced counts of the pathogen Prevotella intermedia and did not interfere with the levels of some beneficial species in relation to the negative control. The treatment of multispecies subgingival biofilm with CPC + Zn was effective in controlling periodontal pathogens and favored the colonization of health-associated bacterial species.

Effectiveness of a mouthrinse containing active ingredients in addition to chlorhexidine and triclosan compared with chlorhexidine and triclosan rinses on plaque, gingivitis, supragingival calculus and extrinsic staining

OBJECTIVES

To assess the effectiveness of three different mouthrinses--chlorhexidine, triclosan + sodium fluoride and chlorhexidine + triclosan + sodium fluoride + zinc chloride--on plaque, calculus, gingivitis and stains and to evaluate the occurrence of adverse effects with these three treatments.

METHODS

Forty-eight healthy subjects participated in a double-blind, randomized, parallel experiment and were randomly allocated to any one of the three experimental mouthrinses: group A (0.2% chlorhexidine (CHX) gluconate), group B (0.03% triclosan + 0.025% sodium fluoride (NaF) + 12% ethyl alcohol) or group C (0.2% CHX + 0.3% triclosan + 0.3% NaF + 0.09% Zn chloride (ZnCl(2)). All the subjects were assessed for gingivitis, plaque, supragingival calculus and extrinsic stains at baseline and at the end of the 21-day experimental period.

RESULTS

There was a significant difference (P = 0.046) in the effectiveness for the prevention of gingivitis and plaque, with subjects of group A and group C presenting least and highest gingival and plaque scores, respectively. Significant differences (P = 0.03) were observed for the accumulation of supragingival calculus where the deposition of calculus in group A was nearly double that of the group B, and group B was most effective in the prevention of supragingival calculus. Highest deposition of extrinsic stains was in the group A followed by group C and group B. There was no significant difference between the three treatments for adverse events' occurrence.

CONCLUSIONS

CHX mouthrinse was most effective in controlling plaque and gingivitis but caused greatest deposition of extrinsic stains. Supragingival calculus deposition was least in triclosan + NaF group followed by CHX + triclosan + NaF + ZnCl(2) and CHX. More than half of the subjects reported adverse events during the experimental phase.

Substantivity of zinc salts used as rinsing solutions and their effect on the inhibition of Streptococcus mutans

The antimicrobial efficacy of zinc (Zn) salts (sulfate and acetate) against Streptococcus mutans (S. mutans) present in the oral cavity was tested in this study. The substantivity of Zn salts was assessed by determining the concentration of Zn in whole, unstimulated saliva and by measuring the magnitude of suppression of salivary S. mutans, 2h after rinsing. The concentration of Zn was measured by atomic absorption spectrometry (AAS) with electrothermal atomization (ET AAS) in saliva sampled before (basal) and 24h after mouth rinsing with different concentrations of Zn (0.1%, 0.5% and 1%) administrated as sulfate and acetate. The estimation of Zn levels in samples collected 30, 60, 90 and 120 min after rinsing was carried out by AAS with flame atomization (FAAS). Immediately after rinsing, the concentration of Zn in saliva sharply increased with respect to the baseline values (0.055+/-0.017 mg/L), followed by a sustained decrease, probably due to clearance of salivary flow or swallowing during sampling. A significant reduction (>87%) in the total mean S. mutans counts was found 2h after rinsing either with sulfate or acetate solutions, as evidence of the high substantivity and effectiveness of the Zn salts tested. A statistically significant inverse relationship (p<0.001 and the Pearson correlation coefficients between -34% and -50%) was found between Zn levels and the respective pH values measured in the samples collected 60 and 120 min after rinsing, sustaining the theory of bacterial glycolysis inhibition.

Influence of alcohol in mouthwashes containing triclosan and zinc: an experimental gingivitis study

OBJECTIVES

An experimental gingivitis model was used to analyse the influence of alcohol in mouthwashes containing 0.15% triclosan and zinc chloride on the formation of supragingival plaque, the development of gingivitis and the appearance of adverse events.

MATERIAL AND METHODS

Using a double-blind crossover design, 30 subjects underwent two consecutive experimental phases with two 0.15% triclosan and zinc chloride mouthwashes, differentiated mainly by their excipient (hydroalcoholic or aqueous). In each phase, the subjects discontinued all oral hygiene measures and were treated solely with the randomly assigned experimental mouthwash for 21 days. Each experimental phase was preceded by a 14-day washout period in which, after receiving a complete oral prophylaxis, the subjects were instructed to perform thorough oral hygiene procedures. Gingivitis and plaque levels were assessed at the start and end of both the experimental phases.

RESULTS

The evolution of the gingivitis and plaque indices showed no statistically significant differences between both treatments. The mean gingival index increased from 0.30 to 0.38 with the non-alcoholic mouthwash and from 0.32 to 0.42 with the hydroalcoholic mouthwash. The respective changes in plaque index were from 0.88 to 1.93 and from 0.94 to 1.92. The hydroalcoholic mouthwash produced a larger number of fresh symptoms (p=0.033), oral itching being the most reported.

CONCLUSIONS

Alcohol does not influence the effectiveness of a 0.15% triclosan and zinc chloride mouthwash against gingivitis development and supragingival plaque formation. The absence of alcohol significantly decreases the incidence of adverse events produced by the mouthwash.

The oral environment: the challenge for antimicrobials in oral care products

For any antibacterial/ anti-plaque system from an oral care product to be effective, it must firstly be delivered and retained at relevant sites in the oral cavity and secondly, remain active within the chosen formulation to successfully target the biofilm cells within dental plaque. This must include inhibition of the growth and metabolism of relevant organisms associated with disease. This review will concentrate on understanding the environmental conditions in which such oral care products must work and summarise the activity within the oral cavity of the main antibacterial and anti-plaque agents in common oral care products, namely chlorhexidine, essential oils, metal salts and Triclosan. Routes to further enhance the activity of these products, together with the use of relatively novel formats such as confectionery products to provide added consumer oral health benefits will be considered.

Antibacterial agents in the control of supragingival plaque--a review

This review considers the main agents which have been used as antibacterial agents in mouthwashes and other vehicles to inhibit the growth of supragingival plaque. The agents discussed are bisguanide antiseptics, quaternary ammonium compounds, phenolic antiseptics, hexetidine, povidone iodine, triclosan, delmopinol, salifluor, metal ions, sanguinarine, propolis and oxygenating agents. The plaque inhibitory, anti-plaque and anti-gingivitis properties of these agents are considered along with their substantivity, safety and possible clinical usefulness. Clinical trials of these agents that have been published are also reported. The possible clinical uses of antiseptic mouthwashes are finally considered along with some advice about assessing manufacturers claims. Throughout this review the terms plaque inhibitory, anti-plaque and anti-gingivitis have been used according to the clarification of terminology suggested by the European Federation of Periodontology at its second workshop. This defines a plaque inhibitory effect as one reducing plaque to levels insufficient to prevent the development of gingivitis; an anti-plaque effect as one which produces a prolonged and profound reduction in plaque sufficient to prevent the development of gingivitis; and anti-gingivitis as an anti-inflammatory effect on the gingival health not necessarily mediated through an effect on plaque.

The effect of mouthrinses containing zinc and triclosan on plaque accumulation, development of gingivitis and formation of calculus in a 28-week clinical test

Experimental mouthrinses containing 0.4% zinc sulphate and 0.15% triclosan, which differed in base formulations were compared to a commercially available non-active control mouthrinse. Following baseline clinical examinations for plaque, gingival bleeding and calculus, the volunteers were provided with a dental prophylaxis and given oral hygiene instruction, stratified into 3 groups and given 1 of 3 mouthrinses. Further clinical assessments were performed after 4, 16 and 28 weeks. Salivary mutans streptococci were also monitored during the study. At 4 weeks, plaque and calculus scores in all groups were low compared to baseline. During the remainder of the study, these improvements were not maintained and both plaque and calculus levels increased in all groups. Plaque was significantly lower (P < 0.05) than in the control at all time points. Calculus was significantly lower (P < 0.05) than in the control at all time points. Calculus was significantly lower at week 28 for experimental mouthrinse group 2. Gingival bleeding also decreased in the initial 4 weeks but increased thereafter in the control group. In contrast, gingival bleeding was significantly (P < 0.05) lower in the two experimental groups than in the control group. No significant changes in mutans streptococci were observed.