In this study the clinical effects of 6 commercially available mouthrinses on the development of plaque and gingivitis and on the tooth surface free energy were evaluated in vivo. The following rinses were used: Hibident ® (containing 0-2% chlorhexidine), Prodent ® (containing 005% sodium fluoride) Meridol ® (containing 125 ppm aminefluoride, 125 ppm stannous fluoride), Merocet ® (containing 0.05% cetylpyridinium chloride), Veadent ® (containing 0.03% sanguinarine) and Listerine ® (containing several phenolic compounds). Sixty test persons were selected and requested to employ the same, non-fluoridated toothpaste over 14 days. At days 0 and 14, the plaque index (PI), gingival index (GI), planimetric plaque index (PP) and the tooth surface free energy were assessed. After this preparatory phase, all oral hygiene was stopped for 6 days and only a rinse twice a day (30 s, 10 ml was used). After this period, the above parameters were measured again. In addition, the microbial composition of the plaque was determined at the beginning (day 0) and the end of the study (day 20). Hibident ® (incorporated in this study as a positive control) demonstrated the lowest PI after 6 days use, whereas Meridol ® demonstrated the lowest GI. PI and GI scores were highest after the use of Prodent ® (incorporated as a negative control). None of the products were able to alter the tooth surface free energy markedly or to cause great shifts in microbial composition of the plaque. Since in this study, 6 products were evaluated in an identical way, the results provide a rigorous basis for comparing their clinical efficacies.

In vitro adsorption of chlorhexidine from a commercially available chlorhexidine-containing (0.12%) mouthrinse (Peridex) on both ground and polished and on saliva-coated enamel was studied by X-ray photoelectron spectroscopy and contact angle measurements. Furthermore, adsorption of salivary constituents was studied on chlorhexidine-treated enamel. Changes in the elemental surface composition obtained by X-ray photoelectron spectroscopy clearly demonstrated adsorption of chlorhexidine from the mouthrinse as indicated by increased N and C signals which were in all cases accompanied by a higher enamel surface free energy, estimated from the contact angle data. In addition, it was found that salivary constituents adsorb less to chlorhexidine-treated enamel than to ground and polished enamel and, moreover, that adsorbed salivary constituents were desorbed by chlorhexidine. In vivo, the effect of a 3-week use of chlorhexidine was compared with the use of a placebo and habitual oral hygiene of 10 volunteers by means of clinical contact angle measurements. Also in vivo adsorption of chlorhexidine yielded elevated surface free energies with respect to habitual oral hygiene or a placebo. Thus in vivo, the well-known favourable effects of the bactericidal properties of chlorhexidine completely overrule the unfavourable effects of high enamel surface free energies.

In this paper, the stationary charging voltage of human dental enamel samples due to photoelectron ejection in an x-ray photoelectron spectrometer is related to the amount of material adsorbed from commercially available mouthrinses and the adsorbed layer thickness. A clear relationship was observed between the charging voltage versus the C/Ca elemental surface concentration ratio, taken as a measure of the amount of adsorbed material. Consequently, a similar relationship was found between charging versus adsorbed layer thickness.

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In this study the bacterial growth inhibiting effects of six commercially available mouthrinses (Hibidenta, Prodent@, Meroceta, Listerinea, Veadenta and Mendola) were determined. Hibidenta was used as a positive control. Five strains were tested (Streptococcus mutans C67, Streptococcus sanguis CH3, Veillonella alcalescens V 1, Lactobacillus acidophilus JP and Actinomyces viscosus C74), as representatives of the supragingival human microflora. The Maximal Inhibiting Dilution (MID) was measured in batch cultures for each product and strain. With respect to the positive control, Hibiden@ (containing 0.2 per cent chlorhexidine), the most effective product was MeridoP (containing 125 ppm aminefluoride 297 and 125 ppm stannous fluoride) followed by Meroceta (containing 0.05 per cent cetylpyridinium chloride), Veadenta (containing 0.03 per cent sanguinarine), Listerinea (containing phenolic compounds) and Prodento (containing 0.5 per cent sodium fluoride). Although all products have been separately reported to yield a plaque reduction in vivo, this study provides a firm basis for a comparison between products, as they were all evaluated in a similar way.