The effect of toothpaste on the propensity of chlorhexidine and cetyl pyridinium chloride to produce staining in vitro: a possible predictor of inactivation

Spectrophotometric Analysis of Dental Enamel Staining to Antiseptic and Dietary Agents: In Vitro Study

Results

The mouthwash containing titanium dioxide (TiO₂) nanoparticles produced the greater enamel discoloration compared to that of chlorhexidine. Brushing had little effect on removal of stains induced by all mouthwashes except for dietary solutions (lemon with sodium bicarbonate and olive with laurel) and distilled water (control).

Conclusion

The results from this study show that mouthwashes containing TiO₂ nanoparticles and other antiseptic mouthwashes cause change in color of the teeth and lead to poor esthetic appearance when compared to dietary and control solutions. Thus, future in vivo studies have to be conducted to confirm these findings as in vitro studies may not provide a reliable simulation of the clinical situations.

An in vitro analysis model for investigating the staining effect of various chlorhexidine-based mouthwashes

Background

There are different mouthwashes containing chlorhexidine in different concentrations, as well as various excipients. Chlorhexidine induce stains or discoloration in teeth and mucous membranes. The aim of this work was to design a model to reproduce in vitro staining associated with the use of different mouthwashes containing chlorhexidine.

Material and Methods

We used as substrates of natural teeth and elephant ivory slices. Different incubation baths were conducted over 21 days in culture dishes at 37°C. At the beginning of experiment before incubation (D0) and after 21 days (D21) of incubation with different mouthwashes, pictures of substrates were taken in a standardized manner and an image analysis software was used to analyse and quantify the staining under the various conditions by using the 3 main colours (Red, Green, Blue, RGB).

Results

The results of this work demonstrate a very good reproducibility of the protocol, and secondly, a different expression statistically significant of the primary blue colour. We suggest that for a given concentration of chlorhexidine, the staining effects may vary depending on the excipients used.

Conclusions

This replicable model, easy to implement over a relatively short duration, can be used for evaluation of existing mouthwashes, and to test the excipients anti discoloration proposed by manufacturers.

Key words:In vitro, chlorhexidine, mouthwashes, dental stain, tooth discoloration.

The staining effect of different mouthwashes containing nanoparticles on dental enamel

Background

This study aimed to evaluate the effects of several mouthwashes containing nanoparticles on discoloration of dental enamel, and compare the results with that of 0.2% chlorhexidine (CHX).

Material and Methods

Sixty intact premolars were randomly assigned to six groups. A spectrophotometer was used to measure the color of the teeth (T1) according to the CIELAB system. The specimens in groups 1 to 4 were then immersed in colloidal solutions containing nanoTiO2 (Group 1), nanoZnO (Group 2), nanoAg (Group 3) and nanoCuO (Group 4). In groups 5 and 6, a 0.2% CHX mouthwash and distilled water were used as positive and negative controls, respectively. After 24 hours of immersion, color determination was repeated (T2). The third color assessment was accomplished after brushing (T3). The L, a, and b values were recorded and the color change (?E) between different stages was calculated.

Results

ANOVA revealed significant between-group differences in the color change between T1 and T2 stages, as well as between T1 and T3 time points (p<0.05), whereas the color change between T2 and T3 was not significantly different among the study groups (p=0.09). ?ET1-T3 was significantly lower in the specimens immersed in distilled water or CHX as compared to the nanoparticle-containing mouthwashes (p<0.05). The highest ?E value pertained to the specimens immersed in nanoZnO-containing solution. The TiO2 nanoparticles caused the lowest staining among the tested nanoparticles.

Conclusions

The mouthwashes containing nanoparticles produced comparable or even greater enamel discoloration compared to CHX. Brushing had little effect on removal of induced stains.

Key words:Nanoparticle, mouthrinse, mouthwash, staining, enamel, discoloration, chlorhexidine.

Long-term efficacy of a 0.07% cetylpyridinium chloride mouth rinse in relation to plaque and gingivitis: a 6-month randomized, vehicle-controlled clinical trial

OBJECTIVE

To evaluate the effectiveness of 0.07% cetylpyridinium chloride (CPC) mouth rinse for reduction of gingival inflammation and inhibition of plaque compared to a vehicle control (VC) mouth rinse over a 6-month period.

MATERIALS & METHODS

Participants (n = 62) used their randomly assigned product as adjunct to toothbrushing. Bleeding, plaque and staining scores were assessed at baseline, 3 and 6 months. Plaque and saliva samples were taken at each assessment monitoring possible shifts in the composition of the microbiota.

RESULTS

A significant difference (P = 0.002) in favour of the CPC mouth rinse, with respect to plaque scores, was found. Bleeding scores at 6 months were not significantly different (P = 0.089). However, when correcting for baseline values, a tendency towards a significant difference in bleeding scores at end trail was observed in favour of the CPC mouth rinse (P = 0.061). Regarding staining at 3 and 6 months, a small but significant difference (8.6% and 10.4%, respectively) (P < 0.0001) was observed with lower scores for the VC group. There was a significant reduction in total anaerobic count in the CPC group at 6 months (P < 0.05). The ratio of aerobes/anaerobes was markedly increased at 3 months, especially in the CPC group. No further differences were observed between groups at 6 months.

CONCLUSIONS

The use of 0.07% CPC mouth rinse was significantly more effective in reducing plaque scores than the vehicle control. Bleeding scores were not different at 6 months. The test product was well accepted and did not cause any serious clinical side effects or negatively affected the microbiota.

Efficacy of a new mouth rinse formulation based on 0.07% cetylpyridinium chloride in the control of plaque and gingivitis: a 6-month randomized clinical trial

AIM

To assess the efficacy of a 0.07% cetylpyridinium chloride (CPC) mouth rinse in the control of plaque and gingival inflammation during a 6-month period.

MATERIAL AND METHODS

Adult subjects with moderate gingivitis were selected [≥40% bleeding on marginal probing (BOMP)]. After retrieving microbiological samples and evaluating the clinical parameters (plaque, BOMP and stain indexes), a professional prophylaxis was performed and subjects were randomly assigned to the test (CPC mouth rinse) or to the placebo group. Subjects were re-assessed after 3 and 6 months.

RESULTS

A total of 67 patients (35 test, 32 placebo) were included in the analysis. At 6 months, intra-group significant plaque reductions were observed in the test group (0.691, p < 0.001), but not in the placebo (0.181, p = 0.653). At 6 months, the mean BOMP values were lower in the test group (p = 0.052). Changes between baseline and 6 months were significantly higher in the test group both for plaque (p = 0.002) and BOMP (p = 0.037) when compared with the placebo. A microbiological impact was observed in the test group, especially for Prevotella intermedia.

CONCLUSION

The evaluated 0.07% CPC-based mouth rinse, used three times per day adjunctively to mechanical tooth cleaning, prevents plaque accumulation and gingival inflammation, as compared to the placebo, for at least 6 months.

Action of food preservatives on 14-days dental biofilm formation, biofilm vitality and biofilm-derived enamel demineralisation in situ

AIMS

The aims of this double-blind, controlled, crossover study were to assess the influence of food preservatives on in situ dental biofilm growth and vitality, and to evaluate their influence on the ability of dental biofilm to demineralize underlying enamel over a period of 14 days.

MATERIALS AND METHODS

Twenty volunteers wore appliances with six specimens each of bovine enamel to build up intra-oral biofilms. During four test cycles of 14 days, the subjects had to place the appliance in one of the assigned controls or active solutions twice a day for a minute: negative control 0.9 % saline, 0.1 % benzoate (BA), 0.1 % sorbate (SA) and 0.2 % chlorhexidine (CHX positive control). After 14 days, the biofilms on two of the slabs were stained to visualize vital and dead bacteria to assess biofilm thickness (BT) and bacterial vitality (BV). Further, slabs were taken to determine mineral loss (ML), by quantitative light-induced laser fluorescence (QLF) and transversal microradiography (TMR), moreover the lesion depths (LD).

RESULTS

Nineteen subjects completed all test cycles. Use of SA, BA and CHX resulted in a significantly reduced BV compared to NaCl (p < 0.001). Only CHX exerted a statistically significant retardation in BT as compared to saline. Differences between SA and BA were not significant (p > 0.05) for both parameters. TMR analysis revealed the highest LD values in the NaCl group (43.6 ± 44.2 μm) and the lowest with CHX (11.7 ± 39.4 μm), while SA (22.9 ± 45.2 μm) and BA (21.4 ± 38.5 μm) lay in between. Similarly for ML, the highest mean values of 128.1 ± 207.3 vol% μm were assessed for NaCl, the lowest for CHX (-16.8 ± 284.2 vol% μm), while SA and BA led to values of 83.2 ± 150.9 and 98.4 ± 191.2 vol% μm, respectively. With QLF for both controls, NaCl (-33.8 ± 101.3 mm(2) %) and CHX (-16.9 ± 69.9 mm(2) %), negative values were recorded reflecting a diminution of fluorescence, while positive values were found with SA (33.9 ± 158.2 mm(2) %) and BA (24.8 ± 118.0 mm(2) %) depicting a fluorescence gain. These differences were non-significant (p > 0.05).

CONCLUSION

The biofilm model permited the assessment of undisturbed oral biofilm formation influenced by antibacterial components under clinical conditions for a period of 14 days. An effect of BA and SA on the demineralization of enamel could be demonstrated by TMR and QLF, but these new findings have to be seen as a trend. As part of our daily diet, these preservatives exert an impact on the metabolism of the dental biofilm, and therefore may even influence demineralization processes of the underlying dental enamel in situ.

The impact of a simple, low-cost oral care protocol on ventilator-associated pneumonia rates in a surgical intensive care unit

OBJECTIVE

The purpose of this study was to determine the effects of a simple low-cost oral care protocol on ventilator-associated pneumonia rates in a surgical intensive care unit.

DESIGN

Preintervention and postintervention observational study.

SETTING

Twenty-four bed surgical/trauma/burn intensive care units in an urban university hospital.

PATIENTS

All mechanically ventilated patients that were admitted to the intensive care unit between June 1, 2004 and May 31, 2005.

INTERVENTIONS

An oral care protocol to assist in prevention of bacterial growth of plaque by cleaning the patients' teeth with sodium monoflurophosphate 0.7% paste and brush, rinsing with tap water, and subsequent application of a 0.12% chlorhexidine gluconate chemical solution done twice daily at 12-hour intervals.

MEASUREMENTS AND MAIN RESULTS

During the preintervention period from June 1, 2003 to May 31, 2004, there were 24 infections in 4606 ventilator days (rate = 5.2 infections per 1000 ventilator days). After the institution of the oral care protocol, there were 10 infections in 4158 ventilator days, resulting in a lower rate of 2.4 infections per 1000 ventilator days. This 46% reduction in ventilator-associated pneumonia was statistically significant (P = .04). Staff compliance with the oral care protocol during the 12-month period was also monitored biweekly and averaged 81%. The total cost of the oral care protocol was US$2187.49. There were 14 fewer cases of ventilator-associated pneumonia, which led to a decrease in cost of US$140 000 to US$560 000 based on the estimated cost per ventilator-associated pneumonia infection of US$10 000 to US$40 000. There was an overall reduction in ventilator-associated pneumonia without a change to the gram-negative or gram-positive microorganism profile.

CONCLUSIONS

The implementation of a simple, low-cost oral care protocol in the surgical intensive care unit led to a significantly decreased risk of acquiring ventilator-associated pneumonia.

Short-term side effects of 0.2% alcohol-free chlorhexidine mouthrinse used as an adjunct to non-surgical periodontal treatment: a double-blind clinical study

BACKGROUND

The aims of this clinical study were to evaluate the short-term subjective (by means of questionnaire) and objective (by means of clinical examination) side effects of 0.2% chlorhexidine (CHX) mouthrinse without alcohol used as an adjunct to non-surgical periodontal treatment and to elucidate the relationship between the subjective and objective evaluations.

METHODS

This was a randomized, double-blind, placebo-controlled clinical trial with two groups: 1) the test group, rinsing with the test product (0.2% CHX without alcohol) twice per day for 1 week, and 2) the control (placebo) group, rinsing with a placebo solution twice per day for 1 week. Following the start of rinsing, patients were subjectively and objectively evaluated for the presence and severity of side effects (pain, burning sensation, pruritus, dryness of mouth, taste disturbance, mucosal irritations, and discoloration of tooth and tongue surfaces) at days 1, 3, and 7 of the rinsing period. The presence of subjective and objective side effects of the groups was compared via use of chi2 and Fisher exact tests. Analysis of the subjective and objective side effects within the evaluation periods was done by McNemar test. Spearman correlation analysis was used to assess the relationships between the subjective and objective side effects.

RESULTS

None of the patients in either group complained of dryness of the mouth. The most commonly reported side effect was the change in color of the labial and buccal mucosa, particularly of the gingiva, after day 3 of rinsing. There were significant (r=0.308 to 0.835; P<0.05) correlations between the discolorations of tongue and tooth surfaces reported by the patients and clinically detected at all evaluation periods. There was a significant and positive relationship between the subjective side effects and the soft tissue irritations when the duration of rinsing increased.

CONCLUSION

Within the limits of this clinical evaluation, rinsing with 0.2% alcohol-free CHX for 1 week caused more irritation to oral mucosa, greater burning sensation, and increased altered taste perception compared to the placebo rinse.

Formulation ingredients for toothpastes and mouthwashes

In order to achieve the multi-claim products required for the dental care category, it is necessary for the formulator to use a variety of different ingredients. This places a number of demands on the development process. Innovations in the areas of pharmaceutical technology have contributed to the formulation of the products having superior efficacy as well as other attributes that may contribute to clinical response and patient acceptability. Improved clinical efficacy and tolerability, along with conditioning signals, should encourage patient compliance with oral hygiene further complementing professional efforts directed at disease prevention. The most effective way of preventing the development of dental disease is in controlling the production of dental plaque. It is formed by microbial action. The removal of plaque from the teeth and related areas is essential for the maintenance of a healthy mouth. In this paper we have presented the main components of toothpastes and mouthwashes. For the active ingredients, their supposed effect as therapeutic agents is also explained.

Development of methods to enhance extrinsic tooth discoloration for comparison of toothpastes. 2. Two-product clinical study

BACKGROUND

Extrinsic staining of teeth is considered to be unsightly and a number of 'whitening' toothpastes have been formulated to inhibit or remove such tooth discoloration. The aim of this study was to compare the stain prevention of two toothpastes.

METHOD

The study was a single-blind, randomised, placebo-controlled, crossover design, balanced for residual effects involving 24 healthy dentate volunteers. The treatments were as follows: (1) a whitening toothpaste product, (2) an experimental toothpaste formulation and (3) water. For each 4-day rinse period, subjects were rendered stain free on the teeth and tongue. Approximately on the hour from 09:00 to 16:00 hours, subjects rinsed with chlorhexidine mouth rinse for 1 min followed by warm black tea for 1 min. The treatment interventions were at 09:00 and 16:00 hours and before the chlorhexidine rinse. The toothpastes were rinsed as 3 g/10 ml water slurries and water as a 10 ml rinse each for 2 min. On day 5, subjects were scored for tooth and tongue stain intensity and area, and the product of these was calculated. The washout period was at least 9 days.

RESULTS

Treatment differences for the teeth were highly significant but not for the tongue. Paired contrasts for tooth stain intensity, area and product were mostly all significantly in favour of reduced staining by the experimental formulation compared with water and the whitening product. There were no significant differences between water and the whitening product.

CONCLUSIONS

Using a forced dietary staining method, the data support a tooth stain-inhibitory/-removal action for the experimental formulation, but not the whitening product.

Effect of toothpaste on the plaque inhibitory properties of a cetylpyridinium chloride mouth rinse

BACKGROUND AND AIMS

Cetylpyridinium chloride (CPC) mouth rinses have moderate plaque inhibitory activity when used alone but rarely have shown adjunctive benefits to tooth brushing with toothpaste. Several explanations for this apparent anomaly can be proferred, including loss of antiseptic activity due to interactions with toothpaste ingredients. The aim of this study was to measure the effect of toothpaste on the plaque inhibitory properties of a CPC mouth rinse using paired rinses of CPC, toothpaste slurry (TP) and water (W).

METHODS

The study was a single blind, randomised, seven-treatment, cross over design balanced for residual effects, involving 21 healthy, dentate subjects. The paired rinses were: W-CPC, CPC-W, TP-CPC, CPC-TP, W-TP, TP-W and W-W. Rinsing with solutions or slurries was done for 60 s twice per day. On day 1, subjects were rendered plaque free, suspended tooth cleaning and commenced the allocated rinse regimen. On day 5, plaque was scored by index. A 2(1/2) day wash out of normal oral hygiene was allowed between each regimen.

RESULTS

The order from lowest to highest plaque scores was as follows: W-CPC = CPC-W < CPC-TP < TP-CPC < or = W-TP < TP-W < W-W. Several differences in pairs of treatments were statistically significant, the most relevant of which were significantly less plaque with W-CPC compared to TP-CPC, TP-W and W-TP, and significantly more plaque with W-W compared to all other regimens except TP-W.

CONCLUSIONS

Toothpaste, whilst possessing some plaque inhibitory activity, when used immediately before a CPC mouth rinse adversely affected the plaque inhibitory action of this antiseptic. This in part may explain the reported lack of adjunctive benefits of CPC rinses to normal oral hygiene practices and supports the suggestion, made for chlorhexidine rinses, that their use should follow toothpaste by at least 60 min.

The propensity of individual saliva to cause extrinsic staining in vitro--a developmental method

OBJECTIVES

To detect any differences in the propensity of individual saliva to cause in vitro staining by chlorhexidine and tea.

METHODS

Unstimulated human saliva was collected on a daily basis and used to coat optically clear Perspex specimens. Specimens were subjected to the original chlorhexidine/tea staining model described by Prayitno and Addy (Journal of Periodontal Research 1979;14:397-402), and cycles repeated until a maximum optical density of two was reached.

RESULTS

Stain development increased incrementally with increasing cycles. Differences in chlorhexidine/tea staining between subjects were obvious by cycle 3 where the lowest 'stainer' had 56% less stain than the highest 'stainer'. Highly significant differences between subjects were seen during staining cycles 3-6, but not at cycles 7 and 8.

CONCLUSIONS

In vitro stain formation using saliva from different individuals occurred at differing rates when all other variables were standardised. The properties of saliva accounting for this are still unknown, and warrant further study.