A comparison of delmopinol and chlorhexidine on plaque regrowth over a 4-day period and salivary bacterial counts

Delmopinol - adsorption to and absorption through the oral mucosa

OBJECTIVES

To investigate the surface chemical changes in dynamic interactions of delmopinol on salivary films on oral mucosa in healthy participants after rinsing with an unbuffered water solution of delmopinol, and to examine the oral tissue disposition of delmopinol in rats after local administration.

MATERIAL AND METHODS

The contact angle technique was used to monitor the interaction of delmopinol with the salivary film coating the upper labial mucosa of 10 healthy participants through a 4 h period. The tissue disposition of ¹⁴C-labelled delmopinol was examined in rats by autoradiography.

RESULTS

Rinsing with delmopinol increased the polarity of the saliva coated mucosa during the time of observation. The binding of delmopinol was verified in the autoradiograms showing that radioactivity remained in the rat oral mucosa after 24 h. Delmopinol was however not irreversibly bound.

CONCLUSIONS

The findings indicate that delmopinol interacts with the salivary film of the upper labial mucosa and affects its polarity. It appears that delmopinol assists in the maintenance of the hydrophilicity of the mucosal pellicle and thereby also reinforcing hydration of the mucosa. The rat autoradiograms, showed that radioactivity remains in the oral mucosa after 24 h, but diffuses through the mucosal membranes into the systemic circulation.

Determining the antibacterial substantivity of Triphala mouthwash and comparing it with 0.2% chlorhexidine gluconate after a single oral rinse: A crossover clinical trial

Context:

Triphala has been extensively used in dentistry as a mouthwash because of its antiplaque and antigingivitis properties.

Aim:

The present study is designed to determine the duration of its antibacterial substantivity after a single oral rinse and to compare it with the substantivity of 0.2% chlorhexidine gluconate (CHX).

Materials and Methods:

In this clinical crossover trial, unstimulated saliva from 30 individuals was collected 2 h after routine oral hygiene procedures but not rinsing (pre-sample) with randomly selected mouthwash, (10% Triphala mouthwash, 0.2% CHX, and normal saline) and 5 min after rinsing (postsample). A washout period of 1 week was kept between two rinses. The sampling was repeated after every 2 h for 12 h (post 1, post 2, post 3, post 4, post 5, and post 6) and was checked for microbial count.

Statistical Analysis Used:

Friedman test, Kruskal–Wallis test, and post hoc analysis were used to assess the effect of different mouthrinses on colony forming units at different times.

Results:

Ten percent Triphala showed statistically significant results when the antibacterial effect at post, post 1 and post 2 were compared to pre-assessment count (P < 0.05). After which the effect was at par with normal saline (P > 0.05). The results for CHX were statistically significant at all times when compared to pre-assessment count (P < 0.05) and it showed the maximum substantivity of 7 h.

Conclusion:

After a single rinse with no eating and drinking restrictions over the day, 10% Triphala mouthwash had an antibacterial effect for 3–4 h. It can be used three times daily for its maximum antibacterial effect.

A clinical and microbiological study on the enantiomers of delmopinol

Objective The clinical part of this study aimed to investigate whether the racemate of delmopinol [(±)-delmopinol] is equivalent to its two enantiomers [(+)-delmopinol and (-)-delmopinol] with respect to efficiency and to determine and compare their pharmacokinetic properties. The purpose of the pre-clinical part was to elucidate possible differences in antimicrobial efficiency. Materials and methods The compounds were tested clinically in a double-blind, randomized, cross-over study comprising three treatment periods of 4 days each. The antimicrobial efficacy of the enantiomers was compared in vitro with respect to planktonic and biofilm bacteria of different species. Results No statistically significant differences in prevention of plaque formation were observed. Except for a somewhat higher systemic exposure in terms of AUC and Cmax indicated for (-)-delmopinol compared to (+)-delmopinol, the pharmacokinetic properties were similar. The most common adverse event was a transient anaesthetic feeling in the mouth. This event was reported with the same frequency for all three test solutions. The enantiomers showed similar antimicrobial effects on planktonic bacteria and their biofilms. Conclusions The enantiomers were found to be equally effective with respect to inhibition of plaque development and only minor differences were observed with respect to their pharmacokinetic properties. No differences could be observed in the adverse events reports. There is, therefore, no reason to use one of the enantiomers of delmopinol instead of the racemate. This was further supported by the antimicrobial tests. It is suggested that the combined action of cationic and neutral delmopinol is important for its effect on biofilms.

Antibacterial and antiplaque efficacy of a commercially available octenidine-containing mouthrinse

OBJECTIVES

The purpose of this clinical study was to determine the antibacterial and antiplaque efficacy of a recently introduced octenidine-containing mouthrinse (Octenidol®) in comparison with established antiseptic mouthrinses.

MATERIALS AND METHODS

In a 4-day plaque-regrowth study employing a four-replicate cross-over design, a 0.1 % octenidine mouthrinse (Octenidol®/OCT-MR) was compared with a 0.12 % chlorhexidine mouthrinse (Paroex®/CHX-MR), an essential oil mouthrinse (Listerine®/EO-MR), and a placebo mouthrinse/P-MR. Plaque regrowth was assessed with a modified Quigley-Hein plaque index. The antibacterial effect was assessed by taking bacterial counts from the tooth surface and oral mucosa after professional tooth cleaning and after first rinsing with the allocated mouthrinse on days 1 and 5. Sixteen volunteers suspended tooth cleaning and rinsed twice daily with the allocated mouthrinse for 4 days.

RESULTS

All tested antiseptic mouthrinses were significantly more effective than the placebo mouthrinse in inhibiting plaque, but no significant differences were observed between OCT-MR and CHX-MR, OCT-MR and EO-MR, and CHX-MR and EO-MR. After 4 days, comparable bacterial count levels were found on both the tooth surface and mucosa applying OCT-MR and CHX-MR, which were significantly lower than that of EO-MR and P-MR.

CONCLUSION

Octenidol® and Paroex® showed comparable antibacterial and antiplaque efficacy in the human oral cavity.

CLINICAL RELEVANCE

The recently introduced octenidine-containing mouthrinse Octenidol® may become a suitable alternative to 0.12 % chlorhexidine-containing mouthrinses such as Paroex®.

Comparing the efficacy of hyper-pure chlorine-dioxide with other oral antiseptics on oral pathogen microorganisms and biofilm in vitro

This study examines the antibacterial properties of sodium hypochlorite (NaOCl), chlorhexidine gluconate (CHX), Listerine®, and high purity chlorine dioxide (Solumium, ClO2) on selected common oral pathogen microorganisms and on dental biofilm in vitro. Antimicrobial activity of oral antiseptics was compared to the gold standard phenol. We investigated Streptococcus mutans, Lactobacillus acidophilus, Enterococcus faecalis, Veillonella alcalescens, Eikenella corrodens, Actinobacillus actinomycetemcomitans and Candida albicans as some important representatives of the oral pathogens. Furthermore, we collected dental plaque from the upper first molars of healthy young students. Massive biofilm was formed in vitro and its reduction was measured after treating it with mouthrinses: CHX, Listerine® or hyper pure ClO2. Their biofilm disrupting effect was measured after dissolving the crystal violet stain from biofilm by photometer. The results have showed that hyper pure ClO2 solution is more effective than other currently used disinfectants in case of aerobic bacteria and Candida yeast. In case of anaerobes its efficiency is similar to CHX solution. The biofilm dissolving effect of hyper pure ClO2 is significantly stronger compared to CHX and Listerine® after 5 min treatment. In conclusion, hyper pure ClO2 has a potent disinfectant efficacy on oral pathogenic microorganisms and a powerful biofilm dissolving effect compared to the current antiseptics, therefore high purity ClO2 may be a new promising preventive and therapeutic adjuvant in home oral care and in dental or oral surgery practice.

In situ chlorhexidine substantivity on saliva and plaque-like biofilm: influence of circadian rhythm

BACKGROUND

The aim of the present study is to assess in situ substantivity of a single mouthrinse with 0.2% chlorhexidine (CHX) on saliva and on undisturbed de novo plaque-like biofilm (PL-biofilm), differentiating between two times of application: 1) CHX mouthrinse in the morning; and 2) CHX mouthrinse at night.

METHODS

The study participants were 10 healthy volunteers who wore an individualized splint with glass disks for 48 hours to boost the growth of PL-biofilm. Saliva samples were collected, and two disks were removed from each volunteer's splint at 8, 10, and 12 hours after performing a mouthrinse with 0.2% CHX at 7:00 am (M-0.2% CHX-diurnal) and 1:00 am (M-0.2% CHX-nocturnal). The saliva and plaque samples were analyzed by epifluorescence and confocal laser scanning microscopy, respectively, using a green fluorescent nucleic acid stain/propidium iodide staining.

RESULTS

With M-0.2% CHX-diurnal, the frequency of vital bacteria in saliva was significantly higher than in the PL-biofilm at 8, 10, and 12 hours after mouthrinse. After M-0.2% CHX-nocturnal, the frequency of vital bacteria in saliva was significantly lower than in the PL-biofilm at 8 hours and higher than in the PL-biofilm at 12 hours after mouthrinse.

CONCLUSION

These results support the more active physiologic dynamics of the salivary flora and the possible reservoir function associated with the structure of undisturbed de novo PL-biofilm.

In vivo substantivity of 0.12% and 0.2% chlorhexidine mouthrinses on salivary bacteria

The in vivo antimicrobial activity of 0.12% and 0.2% chlorhexidine (CHX) on the salivary flora up to 7 h after its application, using epifluorescence microscopy with the SYTO 9/propidium iodide dual staining, was evaluated. Fifteen volunteers performed a single mouthrinse with sterile water (SM-water), a single mouthrinse with 0.12% CHX (0.12% SM-CHX) and a single and double mouthrinse with 0.2% CHX (0.2% SM-CHX and 0.2% DM-CHX). Samples of saliva were taken at 30 s, and 1, 3, 5, and 7 h after each application. In comparison with SM-water, 0.2% CHX (SM and DM) showed a significant antibacterial effect up to 7 h after the mouthrinse, whereas this effect only persisted up to 5 h after the 0.12% SM-CHX mouthrinse. On comparing the two concentrations of CHX, significantly higher percentages of bacterial vitality were observed in all the saliva samples after the use of 0.12% CHX than after 0.2% CHX. On comparison of the 0.2% SM-CHX and 0.2% DM-CHX, significantly higher percentages of live bacteria were observed in the saliva samples taken at 1, 3, 5, and 7 h after the single mouthrinse compared with the double mouthrinse. The 0.2% CHX mouthrinse had the greatest antimicrobial activity on the salivary flora up to 7 h after its application, with a progressive recovery in bacterial vitality. The differences observed with respect to the 0.12% CHX mouthrinse demonstrate the influence of the concentration on its immediate antimicrobial activity and substantivity.

Evaluation of chlorhexidine substantivity on salivary flora by epifluorescence microscopy

OBJECTIVE

To evaluate the in vivo antimicrobial activity of chlorhexidine (CHX) in saliva 7 h after its application using an epifluorescence microscopy technique.

SUBJECTS AND METHODS

Fifteen volunteers performed a single mouthrinse with sterile water (SM-water) and with 0.2% CHX (SM-0.2% CHX). Saliva samples were taken at 30 s and 1, 3, 5 and 7 h after each application. The bacterial suspension was mixed with the SYTO 9/propidium iodide staining and observed using an Olympus BX51 microscope. The mean percentage of viable bacteria was calculated for each sample.

RESULTS

In comparison with baseline values, the frequency of viable bacteria decreased significantly at 30 s after the SM-0.2% CHX (P < 0.001) and presented significant antibacterial activity up to 7 h after the mouthrinse (P < 0.001). In comparison with SM-water, the prevalence of viable bacteria was significantly lower at 30 s after the SM-0.2% CHX (P < 0.001) and showed a significant antibacterial effect up to 7 h after the mouthrinse (P < 0.001).

CONCLUSIONS

Epifluorescence microscopy permits evaluating the antimicrobial activity of CHX on the salivary flora in real-time. Fluorescence assays could be particularly useful to analyse simultaneously the effect of antimicrobials that alter the cytoplasmic membrane integrity on different oral ecosystems.

Meta-analyses of studies of 0.2% delmopinol mouth rinse as an adjunct to gingival health and plaque control measures

BACKGROUND

Delmopinol is a third-generation anti-plaque agent used as a mouthwash to reduce plaque and alleviate gingivitis.

OBJECTIVE

To create an overview of the anti-plaque efficacy of 0.2% delmopinol as an adjunct to normal oral hygiene measures by meta-analysis of completed clinical trials.

MATERIALS AND METHODS

Eight double-blind, parallel-group studies were identified. Study durations ranged from 8 to 24 weeks. Five studies (n=913) involved supervised rinsing; three studies (n=467) involved unsupervised rinsing. These sets of trials were analysed separately and in combination. Efficacy outcomes comprised modified plaque index, modified gingival index (MGI) and gingival bleeding on probing (BOP).

RESULTS

Delmopinol 0.2% was superior to placebo for the reduction of plaque scores in both sets of studies. Effects on MGI and BOP were also better with delmopinol 0.2% than with placebo. In most instances, 95% confidence intervals were wholly in favour of delmopinol. Pooled analysis of all eight studies confirmed statistically significant effects of delmopinol 0.2% compared with placebo (p<0.00001). Delmopinol met the efficacy criteria of the American Dental Association in studies of extended duration.

CONCLUSION

Delmopinol 0.2% mouthwash is effective as an adjunct measure for reducing plaque burden and indices of gingivitis, whether or not it is used under supervision.

How to select the right mouthrinses in periodontal prevention and therapy. Part I. Test systems and clinical investigations

The use of mouthrinses is increasing, especially as adjuncts to the daily mechanical oral hygiene. Different test systems may and can be used to test their antibacterial and clinical effects: bacteriology in vitro, substantivity in vivo, 4-day plaque re-growth, experimental gingivitis and long-term use. The plaque re-growth investigations of a few days are not only of limited use but may also be dangerous because often too extensive conclusions have been drawn from their design. The 'gold standard' test is the experimental gingivitis model to reveal the antiplaque as well as the antigingivitis effects of any mouthrinse preparation during 3 weeks. The last kind of investigations are of several months' duration, where the substances are used as supplements to mechanical oral hygiene measures.

Effect of two antimicrobial agents on early in situ biofilm formation

OBJECTIVES

The aim of this observer-blind, controlled, three-cell cross-over study was to evaluate the influence of an amine fluoride/stannous fluoride (Meridol, 250 ppm; ASF) and a chlorhexidine mouthrinse (CHX; Chlorhexamed forte, 0.2%) compared with water on in situ biofilm growth.

MATERIAL AND METHODS

After a professional toothcleaning seven volunteers had to wear a special acrylic appliance, in which six specimens each were inserted to allow the build-up of intra-oral biofilms. The volunteers had to rinse twice daily for 1 min. with 10 ml of the allocated mouthrinse. After 48 h of wearing, the specimens with the adhering biofilms were removed from the splints and stained with two fluorescent dyes, which selectively stain vital bacteria green and dead bacteria red. Under the confocal laser scanning microscope biofilm thickness (BT) was evaluated. To examine bacterial vitality (BV%) the biofilms were scanned (1 microm sections) and digital images were made. An image analysis program was used to calculate the mean BV as well as the BV of the single sections. After a wash-out period of 14 days a new test cycle was started.

RESULTS

The use of CHX and ASF resulted in a BT of 8.4+/-4.4 mum and 15.7+/-9.9 compared with 76.7+/-29.4 mum using water. The mean vitality (in %) was reduced from 66.1+/-20.4 to 23.3+/-11.6 and 23.9+/-12.4 using CHX and ASF, respectively. Both active solutions reduced BT and BV significantly compared with water (p<0.001). Differences between the two active solutions were not significant (p>0.05).

CONCLUSION

Both mouthrinses showed antibacterial and plaque-reducing properties against the in situ biofilm. The study design enables the examination of an undisturbed oral biofilm and for the first time shows the influence of antibacterial components applied under clinical conditions regarding biofilm formation.

Effect of various chlorhexidine regimens on salivary bacteria and de novo plaque formation

AIM

The aim of the present experiment was to study the effect of different chlorhexidine regimens on the number of bacteria in saliva, and on de novo plaque formation.

MATERIAL AND METHODS

Ten subjects with gingivitis, but no signs of destructive periodontitis, were recruited. Following a screening examination, the volunteers were given oral hygiene instruction, meticulous scaling and professional mechanical tooth cleaning (PTC). The PTC was repeated once every 3 days during a 2-week period to establish healthy gingival conditions. The study was designed as a double-blind cross-over clinical trial including three phases. Each experimental phase comprised one preparatory period of 7 days and one plaque accumulation period (no oral hygiene measures) of 4 days. During all preparatory periods, the volunteers (i) performed mechanical tooth cleaning using a toothbrush and dentifrice and (ii) were, in addition, given two sessions of PTC. The final PTC was delivered after bacterial sampling had been made on Day 0. Preparatory period A: the participants continued the self-performed plaque control regimen that employed only mechanical means. Preparatory period B: the participants were in addition instructed to rinse and gargle, twice daily, with a 0.2% chlorhexidine mouthrinse. Preparatory period C: in addition to the above, the participants were instructed to brush the dorsum of the tongue for 60 s, twice daily, with a 1.0% chlorhexidine gel. Following each plaque accumulation period, there was a 10-day washout interval. The presence and amount of dental plaque (QHI) was scored after 1, 2 and 4 days of no oral hygiene. Samples of saliva were obtained on Day 0 and after 1 and 2 days. The samples were placed on Brucella agar plates and incubated (anaerobically) for 5 days. The total number of colony-forming units was determined and used to estimate the density of bacteria in saliva.

RESULTS

In period A, the mean QHI increased from 1.0 (Day 1) to 1.4 (Day 2) and 2.1 (Day 4). The corresponding scores for periods B and C were 0.5, 0.8, 1.6 and 0.3, 0.8, 1.2, respectively. At all re-examination intervals more plaque formed during period A than during periods B and C. Further, during period C, less plaque formed than that during period B. Saliva samples from Day 0 in period A contained a larger number of TVC than the baseline samples in periods B and C. There was no significant difference in TVC among the groups on Day 2.

CONCLUSION

The daily use of chlorhexidine as an adjunct to mechanical tooth cleaning markedly reduced the number of microorganisms that could be detected in saliva. The number of salivary bacteria may have influenced the amount of plaque that formed during an early phase of no oral hygiene.

Substantivity of toothpaste slurries and their effect on reestablishment of the dental biofilm

OBJECTIVES

Toothpastes are good vehicles for antibacterial substances to exert a prolonged effect. This effect depends on the substantivity and ability to interfere with plaque metabolism and/or vitality. It was the purpose of this clinical, randomized 2 x 4 cell crossover study to evaluate and to compare the antibacterial effects of two toothpastes (Colgate Total(R), COL and Parodontax(R), PAR) applied as slurries on established plaque over 24 h (Part I) and their effect on 4-day plaque regrowth (Part II). Chlorhexamed(R) (0.1%; CHX) and water served as positive and negative controls.

MATERIAL AND METHODS

After professional toothcleaning eight students were asked to refrain from all mechanical hygiene measures for the next 72 h. After 48 h plaque was sampled and vitality of the plaque flora examined (baseline, VF0%). The subjects then rinsed for 1 min with 15 mL of one of the test or control solutions. Every second hour up to 14 h and 24 h after rinsing, plaque sampling and staining was performed to assess plaque vitality (VF2-24, Part I). In Part II, the classical 4-day plaque regrowth design was used with two rinses (1 min) a day as the only oral hygiene measure. Vitality values were assessed on day 1 and day 4 (VF1, VF2). At day 4, teeth were stained to assess the whole mouth plaque index (PlI) and to evaluate the percentage of plaque area (PA) of the anterior teeth.

RESULTS

Compared to placebo, all active rinses reduced plaque vitality significantly over a period of 24 h (Part I). PAR, COL and CHX revealed reductions of 18-31%, 28-50% and 19-50%, respectively. In Part II, similar reductions of all parameters were found for all active rinses (PAR 12-30%, COL 34-51%, CHX 40-64%).

CONCLUSIONS

Colgate Total has shown a significant action on plaque regrowth and a high substantivity during 24 h, while Parodontax revealed a more moderate but still significant effect.

The effect of a polyhexamethylene biguanide mouthrinse compared to an essential oil rinse and a chlorhexidine rinse on bacterial counts and 4-day plaque regrowth

OBJECTIVES

For various clinical applications, polyhexamethylene biguanide hydrochloride (PHMB) has been used for many years as an antiseptic in medicine. Recently, a 0.04% PHMB mouthwash was shown to inhibit plaque regrowth and to reduce oral bacterial counts. In this study, a 0.12% PHMB mouthrinse (A) was compared with a negative control placebo rinse (10% ethanol, flavour) (B), a positive control 0.12% chlorhexidine rinse (C), and a commercially available mouthrinse containing essential oils (Listerine) (D).

MATERIALS AND METHODS

The study was a double-blind, randomised 4-replicate 4 x 4 Latin square cross-over design in which plaque regrowth was measured. The in vivo antibacterial effect was assessed by taking bacterial counts from the tooth surface and mucosa 4 h after the first rinse with the preparations on day 1 and prior to the clinical examination on day 5. 16 volunteers participated and, on day 1 of each study period, were rendered plaque-free, ceased toothcleaning, and rinsed 2x daily with the allocated mouthrinse. On day 5, plaque was scored and smears were collected according to the protocol. Washout periods were 9 days. Data were analysed using ANOVA with Bonferroni HSD adjustment for multiple comparisons (significance level alpha=0.05).

RESULTS

The 0.12% PHMB mouthrinse (A) was significantly more effective in inhibiting plaque than the placebo (B) but no significant differences could be observed between A and 0.12% chlorhexidine (C), or between A and Listerine (D). Bacterial count reductions on the tooth surface with PHMB (A) were significantly greater compared to the placebo (B) after 4 h and significantly greater compared to B and D after 5 days. Chlorhexidine (C) was more effective than A after 5 days. On the mucosa, chlorhexidine (C) was significantly more effective in reducing bacterial counts than the other 3 treatments at both time points investigated. PHMB (A) was significantly more effective in reducing bacterial counts than the placebo (B) after 4 h and after 5 days, and than D after 4 h.

CONCLUSION

Consistent with a previous study, a PHMB mouthrinse was shown to inhibit plaque recolonisation and to reduce oral bacterial counts, indicating that PHMB may find applications in the prevention of plaque-associated diseases.

Preventive strategies and supportive treatment

There is a preponderance of evidence in the literature that periodontal and other oral diseases, such as caries, can be treated and controlled by thorough mechanical plaque removal by the patient, the use of antimicrobial agents and antibiotics when necessary, and participation with the therapist in a well monitored, long-range program of supportive periodontal therapy. Recent evidence suggests that the control and prevention of oral disease, especially periodontitis, is especially important for patients with various systemic conditions that can be impacted by oral infections. It is far better for patients and therapists to practice primary and even secondary prevention with effective plaque control and regular, consistent supportive periodontal therapy, than having to rely on tertiary prevention for disease that has progressed to a level that requires costly treatment, is time-consuming and carries a greater risk of morbidity.

Studies on the effect of polyvinyl pyrrolidone on the activity of chlorhexidine mouthrinses: plaque and stain

BACKGROUND, AIMS

Polyvinyl pyrrolidone (PVP) was shown in vitro to reduce chlorhexidine induced, dietary staining without affecting the uptake of the antiseptic to the test substrate. The aim of these studies in vivo was to determine whether PVP affected plaque and dietary staining by a low concentration chlorhexidine rinse.

METHODS

The plaque and stain studies used a double blind, randomised 6, treatment crossover design involving healthy subjects with a high standard of oral hygiene and gingival health. The rinse formulations under test were: (A) aqueous alcohol (placebo control), (B) 0.03% chlorhexidine, (C) 0.06% chlorhexidine, (D) 0.06% chlorhexidine+1.2% PVP, (E) 0.06% chlorhexidine+5% PVP, (F) 0.06% chlorhexidine+10% PVP. In the plaque study, on day 1 of each period, subjects were rendered plaque free and then rinsed with 15 ml of the test rinse for 60 s. No further tooth cleaning was performed and subjects returned 24 h later for plaque scoring by area. In the stain study, on day 1 of each period, the tongue and teeth of each subject were rendered stain free. Subjects then rinsed under supervision for 60 s with 15 ml of the allocated rinse 8 x a day between 09:00 h and 17:00 h for 3 days. Immediately after each rinse with the test formulation, subjects rinsed for 120 s with 15 ml of warm black tea. Subjects were requested to also drink at least 5 cups of tea or coffee per day. On day 4, stain was scored by area and intensity from designated teeth and dorsum of the tongue. Washout periods were at least 7 days in both studies.

RESULTS

Plaque areas were greatest with placebo and least with 0.06% chlorhexidine. Plaque scores increased with increasing concentrations of PVP in the 0.06% chlorhexidine rinse and were significantly higher than 0.06% chlorhexidine without PVP rinse. Tooth stain areas were comparable for placebo, 0.03% and 0.06% chlorhexidine rinses, but significantly reduced with the PVP/chlorhexidine rinses compared to the 0.06% chlorhexidine rinse. Tooth stain intensity was significantly increased with 0.06% chlorhexidine rinses compared to placebo and chlorhexidine/PVP rinses. Tongue stain area and intensity were significantly reduced with 5% and 10% PVP/chlorhexidine rinses compared to 0.06% chlorhexidine rinse.

CONCLUSION

PVP, at the concentrations tested, reduced the stain propensity of a 0.06% chlorhexidine rinse but at the expense of some loss of plaque inhibition.

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.

Pharmacokinetics of 14C-delmopinol in the healthy male volunteer

1. The absorption and excretion of delmopinol, an inhibitor of plaque formation and gingivitis, were studied in healthy male volunteers. Each subject received a single dose of a 10-ml aqueous solution of 14C-delmopinol at 2 mg/ml as a 1-min mouth rinse (the intended route of administration; n=6) or as an oral dose (n=6). 2. After mouth rinsing, 72% of the dose was expectorated. The retained portion of the dose was rapidly absorbed and eliminated. Of the dose, 25% was recovered in the urine. Renal excretion was predominant also after oral administration with 92% of the dose excreted in the urine. The total recovery of 14C-activity after 6 days was 99% (rinsing) and 95% (oral) with the bulk, 20% (rinsing) and 80% (oral), of the dose excreted already within 8 h. 3. Peak plasma levels of 14C-labelled compounds were attained at 1.5 h after rinsing and 0.5 h after oral administration; total concentrations were approximately 200 and 3000nmol/l, respectively. For parent delmopinol, peak plasma levels of 49 nmol/l (rinsing) and 8 nmol/l (oral) occurred after 1.5 and 1.3 h, respectively. After rinsing, the concentration of delmopinol declined with a half-life of 2.4 h. The plasma level of 14C-labelled compounds declined multiphasically. In the terminal elimination phase (after 72 h) remaining radioactivity, < 2% of dose (rinse) and < 5% of dose (oral), decreased with a half-life of approximately 130 and 160 h, respectively. 4. Results indicate a very low bioavailability (1-3%) due to extensive first-pass metabolism of delmopinol after oral administration. A high plasma clearance (> 60 l/h) and a large volume of distribution (> 200 l) were also indicated. 5. The results of rapid and almost complete recovery in the urine support that delmopinol can safely be used in the treatment of patients with plaque or gingivitis.

6-month use of 0.2% delmopinol hydrochloride in comparison with 0.2% chlorhexidine digluconate and placebo. (I). Effect on plaque formation and gingivitis

A double-blind, randomised, 6-month clinical trial with parallel group design in 149 patients with gingivitis was conducted to study the efficacy and safety of delmopinol hydrochloride 2 mg/ml (0.2% w/v, Decapinol Mouthwash) used for partly supervised mouthrinsing in comparison with chlorhexidine digluconate 2 mg/ml (0.2% w/v, Hibitane Dental, ICI Pharmaceuticals, UK) and placebo as an addition to normal oral hygiene. Assessments of efficacy were performed using the plaque index and bleeding on probing (BOP). Delmopinol showed 22% lower plaque index scores than placebo after 3 months (p<0.01) and 13% lower scores after 6 months. The corresponding figures for chlorhexidine were 38% (p<0.001) and 38% (p<0.001) after 3 and 6 months, respectively. Bleeding on probing was reduced for delmopinol in comparison with placebo by 11% after 3 months and by 18% (p<0.05) after 6 months. For chlorhexidine the corresponding figures were 18% (p<0.01) and 22% (p<0.01) after 3 and 6 months, respectively. While chlorhexidine showed greater plaque reduction than delmopinol (p<0.01 at 6 months), no statistically significant difference was reached between these two solutions regarding BOP. Both active solutions showed an increased amount of dental calculus in comparison with placebo. A transient anaesthetic sensation in the oral mucosa and taste affection were commonly reported adverse events in both the delmopinol and the chlorhexidine groups. The number of patients withdrawn from treatment due to adverse events or lack of cooperation was 7 in the chlorhexidine group, 4 in the placebo group and 1 in the delmopinol group. The results showed that rinsing with either 0.2% delmopinol hydrochloride or 0.2% chlorhexidine digluconate twice daily for 60 secs for 6 months results in less plaque formation and gingivitis than rinsing with placebo. Mouthrinsing with the 0.2% delmopinol hydrochloride solution was well accepted in this study.

Plaque formation and gingivitis after supervised mouthrinsing with 0.2% delmopinol hydrochloride, 0.2% chlorhexidine digluconate and placebo for 6 months

OBJECTIVES AND METHODS

A double-blind, randomized, 6-month clinical trial with parallel group design in 162 patients with gingivitis divided into three rinsing groups was conducted in order to study the efficacy and safety of a flavoured solution of delmopinol hydrochloride 2 mg ml-1 (0.2% w/v, Decapinol Mouthwash) used for supervised mouthrinsing in one rinsing group, in comparison with chlorhexidine digluconate 2 mg ml-1 (0.2% w/v, Hibitane Dental) in a second rinsing group, and placebo in the third group. The criteria of the Plaque Index (PI) were used to assess plaque formation. Bleeding on probing (BOP) to the bottom of the pocket with a standard pressure was used as the primary gingivitis assessment. The occurrence of supragingival dental calculus and extrinsic tooth staining were also assessed. In addition, patients were asked to report adverse events at each visit.

RESULTS

Delmopinol and chlorhexidine exhibited lower scores of the mean PI and the BOP percentage than placebo, both at the 3-month and 6-month examinations. Furthermore, both active solutions showed a higher extent of staining of the teeth than placebo during these two observation periods. Rinsing with chlorhexidine resulted in more dental calculus than placebo after 6 months. Chlorhexidine showed lower scores for plaque formation and gingivitis development but higher scores of supragingival dental calculus (after 6 months) and tooth staining than did delmopinol. Both active solutions were reported by the patients--approximately to the same extent but more frequently than placebo--to induce taste alterations and a transient anaesthetic sensation of the oral mucosa. However, subjective staining of the teeth and tongue was reported by 16% of the delmopinol patients, but by 86% of the patients rinsing with chlorhexidine for 6 months. Furthermore, 24% of the patients in the chlorhexidine group, 9% in the delmopinol group and 4% in the placebo group wished to withdraw from treatment.

CONCLUSIONS

The results from this clinical trial indicate that supervised rinsing with 0.2% delmopinol hydrochloride or with 0.2% chlorhexidine digluconate twice daily for 60 s as a supplement to normal mechanical oral hygiene procedures resulted in less plaque formation and gingivitis than rinsing with placebo. Although chlorhexidine was more effective than delmopinol regarding plaque formation and gingivitis, it was considered by the patients as less tolerable.

The comparative effect of acidified sodium chlorite and chlorhexidine mouthrinses on plaque regrowth and salivary bacterial counts

Acidified sodium chlorite (ASC) is recognised as a highly potent, broad spectrum antimicrobial system that has been successfully developed for uses in veterinary, food processing and medical device fields. The current studies aimed to investigate the persistence of antimicrobial action and plaque inhibitory properties of 3 ASC mouthrinses by comparison with positive control, chlorhexidine 0.12%, and placebo control, water, rinses. Both studies were randomised, double-blind, cross-over 5-cell designs balanced for carryover. The 1st study involved 15 healthy subjects who immediately before and at 30, 60, 180, 300 and 420 min after rinsing provided 2 ml saliva samples. The samples were immediately processed for total anaerobic bacterial counts recorded after 96 h incubation. Washout periods were a minimum of 3 days. The second study involved 20 healthy subjects who on day 1 of each study were rendered plaque free, suspended normal oral hygiene methods and commenced rinsing twice daily with the allocated rinse. On day 5, plaque was scored by index and area after disclosing with erythrosin. Washout periods were 2 1/2 days. The 3 ASC and chlorhexidine rinses produced similar reductions in salivary bacterial counts which remained significantly below the placebo control to 7 h. There were no significant differences between ASC and chlorhexidine rinses except at 30 and 60 min when significantly greater reductions were produced by 2 ASC rinses compared to the chlorhexidine rinse. Plaque indices and areas were considerably and significantly lower with the ASC and chlorhexidine rinses compared to the placebo rinse. There were no significant differences between plaque scores for the 3 ASC rinses and the chlorhexidine rinse, although for 2 ASC rinses plaque scores were lower than for the chlorhexidine rinse. The results indicate that the 3 ASC rinses have equivalent plaque inhibitory action to chlorhexidine as a rinse. Similar to chlorhexidine, the plaque inhibitory action of the rinses appears to be derived from a persistence of antimicrobial action in the mouth.

Effect of delmopinol hydrochloride mouthrinse on plaque formation and gingivitis in "rapid" and "slow" plaque formers

The aim of the present study was to investigate differences in the plaque and gingivitis inhibiting effect of delmopinol rinsing between "rapid" and "slow" plaque formers. 23 subjects (12 "rapid" and 11 "slow" plaque formers) were selected from 71 healthy young adults. The selection was based on the plaque index on the buccal surfaces of all premolars and 1st molars after 3-days without plaque control. The 23 subjects were randomly assigned into 3 groups with different mouthrinses, i.e., 0.1% delmopinol, 0.2% delmopinol, and placebo. The study was double-blind with parallel design between the "rapid" and "slow" plaque formers and cross-over design between 2 active periods and a placebo period. Each rinsing period lasted for 5 days. During the 3 test periods, the subjects refrained from all oral hygiene and rinsed 2x daily with either one of the 3 solutions. Gingival crevicular fluid (GCF) was collected from buccal surfaces of upper canines and premolars and bleeding on probing (BOP) recorded at 6 sites around each tooth before and after each test period. Plaque assessment, including plaque index (PI) and standardized color slides for planimetric analyses obtained from the canines and premolars, were only recorded after each test period. Results showed that the mean PI and planimetry values for both the "rapid" and "slow" plaque formers were lower than the placebo, for either the 0.1% or the 0.2% delmopinol mouthrinse. The differences between the" rapid" and "slow" plaque formers were not statistically significant. There was a small reduction in BOP in both groups for the delmopinol periods, as against a slight increase in the placebo period; the difference between the placebo group and the 2 groups of plaque formers was not statistically significant (p>0.6 for both 0.1% and 0.2% delmopinol). Results suggested that both 0.1% and 0.2% delmopinol reduce plaque formation and gingivitis to a similar extent in subjects with extreme rates of plaque formation.

An evaluation of an antiadhesive copolymer agent on plaque inhibition by chlorhexidine

The high molecular weight copolymer M239144 has proven antiadhesive action in vitro but clinically lacked effect, even when combined with chlorhexidine. This latter result was thought to arise from inactivation of chlorhexidine by the copolymer. The aim of this study was to determine whether improved activity might arise if the copolymer and chlorhexidine were applied sequentially rather than combined. The study was a double-blind, randomised crossover design balanced for carryover using a 24-h plaque regrowth method. 2 groups of 25 subjects from a zero plaque baseline rinsed 1x with 15 ml volumes of the allocated paired rinses for 60 s. Subjects abstained from toothcleaning for 24 h and were scored for plaque by area. The paired regimens were: 1. placebo: placebo; 2. placebo: 0.03% chlorhexidine; 3. 1% co-polymer and 0.03% chlorhexidine; 4. placebo: 1% co-polymer; 5. placebo: 0.12% chlorhexidine. Plaque regrowth was greatest with regimen 1 and least with regimen 5. However, regimens 3 and 4 were not significantly different from regimen 1, whereas regimen 2 was significantly more effective than regimen 3. The results indicate that the copolymer alone is ineffective, and even delivered sequentially, inactivates chlorhexidine.

Effect of local application of delmopinol hydrochloride on developing and early established supragingival plaque in humans

The aim of the study was to investigate the effect of delmopinol hydrochloride on the development of dental plaque and on newly established plaque. In addition, the influence of this compound on the composition of the microbiota colonizing the gingival mucous membrane was studied. 14 healthy male volunteers took part. After a 3 week pre-experimental period of intense oral hygiene, the participants refrained from all oral hygiene for 14 days. The buccal surfaces of cuspids and bicuspids on one side of the jaws were treated with a 1% aqueous solution of delmopinol hydrochloride (applied with a paint brush) 2 x a day for 7 days, while the contralateral side received placebo solution. On day 7, the application procedures were changed in that the test compound was applied on the teeth previously treated with placebo and vice versa. Plaque development was assessed clinically and by photo-based planimetric determination. The clinical recordings revealed that 89.3% of the placebo-treated surfaces displayed visible plaque on day 7, compared to 6.0% of the delmopinol hydrochloride treated surfaces. Delmopinol hydrochloride treatment of the previously placebo-treated surfaces resulted in a decrease in the number of surfaces with visible plaque from 89.3% on day 7 to 6% on day 14. These results were confirmed by the planimetric data. No significant change in the composition of the mucosal flora was observed during the experimental period. The present results indicate that delmopinol hydrochloride markedly reduces the formation of dental plaque on a clean tooth surface exposed to conditions which favour bacterial colonization. Furthermore, the substance appears to possess plaque-dissolving properties.

A 6-month home-usage trial of 0.1% and 0.2% delmopinol mouthwashes (I). Effects on plaque, gingivitis, supragingival calculus and tooth staining

Delmopinol is a morpholinoethanol derivative which, in mouthrinses used in the absence of normal oral hygiene, has been shown effective in the inhibition of plaque and gingivitis. The aim of this study was to determine the adjunctive oral hygiene benefits and safety of delmopinol rinses when used alongside normal toothcleaning. This 6-month home use study was a placebo-controlled, double-blind, randomised parallel design evaluating 0.1% and 0.2% delmopinol rinses and structured to conform with the ADA Council of Dental Therapeutics guidelines. A total of 450 dentate male and female subjects were recruited who had no relevant medical or pharmacotherapy histories determined from a full medical examination, including haematological and biochemical tests. Subjects had moderate levels of plaque and gingivitis. At baseline, 3 and 6 months subjects were scored for plaque, gingivitis, tooth stain and supragingival calculus, with plaque sampled for microbiological analysis. Additionally, oral mucosal examinations were performed and subjects questioned for adverse symptoms. Baseline special tests were repeated at the end of the study. After baseline examinations, the subjects received a professional prophylaxis, provided with the allocated mouthwash and instructed to use 10-ml volumes for 60 s 2 x daily and where appropriate after toothbrushing and meals. Demographic features of the 3 groups were similar and losses to trial were small. Adverse signs and symptoms included transitory numbness of the tongue, tooth and tongue staining, taste disturbance and rarely mucosal soreness and erosion. All local side-effects were less commonly reported at 6 compared to 3 months and only 6 subjects were withdrawn because of adverse event. No systemic effects attributable to the agent were observed and no significant shifts in haematological or biochemical parameters occurred. All groups showed considerable improvements in oral hygiene and gingival health with some significant differences in favour of 0.2% delmopinol compared to placebo for gingivitis and more particularly plaque. Staining was also significantly increased in the delmopinol groups but not calculus. In the present study, a considerable Hawthorne effect occurred, which must in part explain why only a modestly significant effect was achieved.

The effect of a commercially available triclosan-containing toothpaste compared to a sodium-fluoride-containing toothpaste and a chlorhexidine rinse on 4-day plaque regrowth

Many compounds could be added to toothpaste to assist plaque inhibition, but ionic interactions can cause formulation difficulties. Moreover, the actual chemical action of a plaque inhibitory agent added to a toothpaste is difficult to assess when the product is used in the conventional manner, i.e., in addition to toothbrushing. The non-ionic antimicrobial triclosan has been incorporated in toothpastes and shown to have variable plaque inhibitory activity both alone and in conjunction with certain polymers or metal ions. Little is known of the efficacy of triclosan toothpastes compared to conventional fluoride toothpastes. The aim of this study was to compare a commercially available toothpaste containing 0.3% triclosan/co-polymer with a sodium fluoride toothpaste for chemical plaque inhibitory effects over a 4-day period. The study was designed to stratify the relative efficacy plaque inhibitory action of the products, comparisons were made with a positive control, chlorhexidine rinse and a negative control, saline. The study design was a randomised single blind crossover design balanced for first-order carryover. A total of 18 healthy, dentate volunteers participated in the study. On day 1 of each period the volunteers suspended toothcleaning and rinsed 2 x daily with the allocated mouthrinse or toothpaste slurry. On day 5, the plaque on the teeth was disclosed and scored by index and area. Increasing plaque scores were in the order chlorhexidine, triclosan toothpaste, fluoride toothpaste, and saline. Chlorhexidine was significantly more effective than all the other agents tested, and both toothpaste preparations were significantly better than the saline rinse. There was no significant difference between the two toothpaste rinses. Consistent with other studies the triclosan toothpaste offers only moderate plaque inhibitory properties when compared to a conventional toothpaste.

The efficacy of Decapinol mouthwash 2 mg/mL in preventing gingivitis

In vitro studies and early clinical trials have shown promising results for Delmopinol HCl solution as an effective mouth rinse for reducing experimentally induced gingivitis in the absence of mechanical plaque control. The efficacy of Decapinol mouthwash 2 mg/mL (Delmopinol HCl) in preventing gingivitis in a double-blind, randomized clinical study with parallel group design was studied. Forty-seven healthy young adults were randomly assigned to the Delmopinol or placebo groups. After an initial period of four weeks of intensive oral hygiene including bi-weekly professional cleaning of the teeth and oral hygiene instruction, all subjects achieved a low degree of gingivitis or a plaque score close to zero. At baseline, Bleeding on Probing, Modified Gingival Index and Plaque Index were recorded and the teeth were professionally cleaned. All forms of plaque control were then suspended and subjects were supervised in a one-minute rinsing of Decapinol mouthwash 2 mg/mL or placebo twice daily. Measurements of efficacy variables were then repeated after two and three weeks treatment and adverse events were recorded. After the study period of three weeks all previous plaque control measures were resumed. At week four, all subjects were reassessed for the resolution of gingival inflammation and where residual gingival inflammation persisted, appropriate treatment was given. Only mild and short-lasting adverse events were noted for the use of Delmopinol in the study period. However, for all teeth sites measured, significant differences between Delmopinol and placebo groups were found in Bleeding on Probing (p < 0.05) and Plaque Index (p < 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)

A 6-month home-usage trial of 0.1% and 0.2% delmopinol mouthwashes (II). Effects on the plaque microflora

The effects of 0.1% and 0.2% delmopinol mouthwashes on supragingival plaque flora were investigated in a 6-month home-use study. 141 subjects were studied from whom plaque was collected at baseline, 12, 24, and 36 weeks. Overall, there were no consistent effects on microscopic or total counts. However, there was a significant reduction in the proportion of dextran-producing streptococci in the active groups compared to the control group throughout treatment. There was no colonisation by Candida or Gram-negative aerobic bacilli in the active groups nor was there any decrease in susceptibility to delmopinol. Delmopinol appears to mediate its anti-plaque effect without causing a major shift in bacterial populations, although dextran-producing bacteria appear to be affected, which may have relevance to this agent's mode of action.

Plaque formation and gingivitis after mouthrinsing with 0.2% delmopinol hydrochloride, 0.2% chlorhexidine digluconate and placebo for 4 weeks, following an initial professional tooth cleaning

A double-blind, randomised, 4-week clinical trial with parallel group design in 57 patients with gingivitis was conducted for studying the antibacterial efficacy and safety of a delmopinol HCl aqueous solution 2 mg/ml (0.2% w/v), which was used for unsupervised mouth-rinsing and compared with placebo and chlorhexidine digluconate 2 mg/ml (0.2% w/v, Hibitane Dental, ICI Pharmaceuticals, UK). The plaque index and plaque wet weight were used to measure plaque formation, and gingival fluid flow and bleeding on probing to measure gingivitis. According to the reduction from baseline, chlorhexidine showed a significantly better effect on plaque formation than the placebo after 4 weeks treatment for both plaque measurements. Delmopinol exhibited significantly lower plaque index scores than placebo. The difference between chlorhexidine and delmopinol was not statistically significant for any of the plaque measurements. For gingivitis, no statistically significant differences were obtained between the effects of delmopinol, chlorhexidine and placebo. A transient anaesthetic sensation in the oral mucosa was experienced more clearly by the patients in the delmopinol group than by those using chlorhexidine or placebo rinses. Rinsing with chlorhexidine resulted in more staining of the teeth and tongue than did delmopinol and placebo. The placebo solution tasted better than the 2 active solutions. The results showed that rinsing with either delmopinol HCl aqueous solution 2 mg/ml or chlorhexidine digluconate 2 mg/ml 2x daily for 60 as a supplement to normal oral hygiene, following an initial professional tooth cleaning, leads to a lower plaque formation than rinsing with placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of plaque and gingivitis after mouthrinsing with 0.2% delmopinol hydrochloride

A double-blind, randomized, 2-wk experimental gingivitis clinical trial with cross-over design in 14 dental students was conducted in order to study the efficacy and safety of delmopinol hydrochloride solution (2 mg/ml), used with no other oral hygiene procedures, in comparison with placebo. Plaque formation was measured by the Quigley & Hein Plaque Index and gingivitis was assessed by bleeding on probing according to Mühlemann & Son. Rinsing with delmopinol resulted in lower plaque scores compared to placebo. The development of gingivitis was weak during the 2-wk test periods, and thus no conclusive results were obtained. As in previous studies, the most frequent adverse event when rinsing with delmopinol was a transient anaesthetic sensation in the oral mucosa. The results showed that rinsing with delmopinol hydrochloride solution (2 mg/ml) for 60 s twice daily with no other oral hygiene procedures led to less plaque formation than rinsing with placebo. This study also showed good tolerance and acceptability of mouthrinsing with delmopinol.

Delmopinol interactions with cell walls of gram-negative and gram-positive oral bacteria

The main purpose of the present study was to investigate the influence of delmopinol hydrochloride on the cell surface morphology of gram-negative and gram-positive bacterial cells by using transmission electron microscopy. A second purpose was to evaluate the extraction of cell wall material caused by delmopinol and the binding of radiolabelled delmopinol to the various strains. Fresh isolates and type strains of gram-negative rods associated with periodontal disease, Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans, and strains of the gram-positive streptococci Streptococcus sanguis, Streptococcus mutans and Streptococcus salivarius, were exposed to 3.2 mM (0.1%) or 6.4 mM (0.2%) delmopinol hydrochloride from 1 to 90 min. For electron microscopy the cells were fixed and negatively contrast-stained. Treatment with 6.4 mM delmopinol for 1 min resulted in marked ultrastructural changes of cell wall components and the outer cell membrane of the 3 gram-negative species compared with control cells, whereas the gram-positive streptococci treated with delmopinol showed little or no morphologic alteration as compared with untreated cells. The result from the electron microscopy was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of proteins released from bacterial cells treated as for electron microscopy. More material was extracted from the gram-negative rods than from the gram-positive cocci. Significantly more delmopinol bound to the gram-negative rods than to the streptococci. It appears that the amphiphilic properties of delmopinol make gram-negative rods more vulnerable to delmopinol than gram-positive streptococci.

Pharmacological control of periodontal disease. I. Antiplaque agents

Inhibition of the development of dental plaque remains one of the primary aims of periodontal care. Many patients, however, are unable to master completely the mechanical methods of plaque control and for this reason, considerable research efforts have been directed towards the development and use of chemical agents to inhibit the growth of plaque. This first of two articles, therefore, examines the pharmacological properties and efficacy of commercially available antiplaque agents. We have also summarized the findings of some of the major clinical trials that have provided the scientific basis for the introduction of these agents for the management of gingival inflammation.

Effect of chlorhexidine and toothbrushing on the presence of bacteria on gingival and buccal epithelial cells

Swabs of buccal and gingival epithelial cells from healthy young adult donors were washed in physiological saline solution, smeared on glass slides and stained with acridine orange. The presence of bacteria attached onto epithelial cells was examined under a fluorescence microscope. Four hours after a chlorhexidine rinse, the number of cells with > 50 attached bacteria had almost completely vanished. The degree of bacterial colonization seemed to re-establish at a level exceeding the baseline. One week after chlorhexidine treatment the degree of colonization was still over the control level. Toothbrushing with a conventional toothpaste reduced immediately the number of cells with > 50 bacteria. The colonization had re-established to the pre-washing levels at the buccal sites at 1 h and at the gingival sites at 4 h after toothbrushing. A method for the evaluating of the antimicrobial power of oral hygiene products is presented.

Mouthrinses

Mouthrinses have been used for centuries for medicinal and cosmetic purposes, but it is only in recent years that the rationale behind the use of the ingredients has been subject to scientific research and clinical trials. Although Listerine held its position for many years in the vanguard of the anti-plaque agents, the advent of mouthrinses containing chlorhexidine was a major breakthrough in the research for a chemical means to prevent disease. Since that time, and especially in the past ten years, the number of formulations that claim to have anti-plaque, anti-calculus, and anti-caries activity has increased, and much emphasis has been placed on such substances as an adjunct to, or indeed to replace, conventional toothbrushing techniques. This review covers the literature on mouthrinses over the past five years, concentrating more on the anti-plaque, anti-gingivitis, and anti-calculus formulations. In the first section, the methods of conducting clinical trials of mouthrinses are discussed, and a plea is made for a greater degree of standardization of methodology with agreed acceptable levels of clinical benefit. Trials of established mouthrinses are considered, and the advantages and disadvantages of several newer formulations discussed. From the review, it appears that chlorhexidine has no equal in its effects on reduction of plaque and gingivitis, but major drawbacks lie in the taste and stain-producing problems. The pre-brushing rinse, Plax, does not have unqualified success in all trials, though the more recent European formulation may have promise. Newer rinses which inhibit bacterial adhesion to tooth surfaces also appear promising, and it is suggested that more work on combinations of active ingredients is necessary.

Short-term effect of topical application of delmopinol on salivary microbiology, plaque, and gingivitis

The aim of this study was to test a possible dose-response effect of topical application of delmopinol HCl on the salivary microbiology, the healing of a pre-established experimental gingivitis, plaque development, and supragingival plaque composition. Forty-eight healthy subjects were enrolled in an oral hygiene program for 2 wk to upgrade their oral health. After professional tooth cleaning, they abstained from all oral hygiene, but applied 2 ml of a placebo with a soft paintbrush onto their teeth twice daily for 2 wk. At the end of this period, the subjects received tooth cleaning and were then assigned to three treatment groups of 16 individuals each. They applied 2 ml of 0.1%, 0.5%, and 1% delmopinol HCl, respectively, twice daily for the next 2 wk and refrained from all other oral hygiene procedures. At the end of the placebo and delmopinol HCl treatment periods, (1) saliva samples were obtained and cultivated on a series of media, (2) the degree of gingivitis was measured with gingival crevicular fluid (GCF) and gingivitis index (GI), (3) the stainable buccal plaque extension was analyzed planimetrically, and (4) the bacterial morphotypes of plaque adjacent to the gingival margin were analyzed. No changes in the salivary microbiologic counts were detected. The amounts of GCF and GI were reduced in all delmopinol groups, as compared with placebo. Mean plaque extension was reduced by 16% for the 0.1%, 56% for the 0.5%, and 58% for the 1% delmopinol group. Cocci appeared to predominate in bacterial dental plaque when 0.5% and 1% delmopinol were used.(ABSTRACT TRUNCATED AT 250 WORDS)

Annual review of selected dental literature: report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The annual review of selected dental literature this year cites 384 published papers and reports. This year's review contains more editorial comment than reviews of years passed. New data on the biological responses to materials is emphasized in several sections. Observations on new compounds able to prevent plaque formation are presented. Clinically relevant advances in knowledge concerning the etching of different tooth structures are reported along with the effect of etching procedures on the dental pulp. Evaluation of periodontal diseases in all age groups is a topic. Limitations of current diagnostic techniques in periodontal disease, temporomandibular disorders, and implant therapy are included. There are new views on the use of dental amalgam. The future use of dental mercury is predicted. Interest in new ceramic systems is indicated as the demand for esthetics continues. Clinical information is emphasized over scientific information throughout this year's review.

Scanning electron microscopic observations of early plaque formation in vivo on enamel specimens treated with delmopinol

The aim of this double blind, cross-over, scanning electron microscopic (SEM) study was to compare the effect of topical application of 0.5% delmopinol HCl (aqueous solution) with placebo on early supragingival plaque formation on enamel specimens attached to a maxillary premolar. 3 subjects underwent 2x (placebo and delmopinol treatment, respectively) 7 treatment periods (1/2, 1, 2, 8, 24 hours; 3, 7 days) of undisturbed dental plaque accumulation, during which 2 ml of placebo and delmopinol HCl 0.5%, respectively, were applied topically to all teeth 2x daily. At the end of each period, the specimen was retrieved and processed for SEM. For the specimens obtained after 24 h or less, the number of visible micro-organisms was estimated. For the 3- and 7-day specimens, the area covered by plaque was calculated planimetrically. Large inter-individual differences were observed in the number of bacteria attaching during the first 24 h, with apparently no major differences between delmopinol and placebo. 1 subject showed a bacterial colonization predominated by curved rods throughout the first 8 h. Compared to placebo, the area of the specimens covered by plaque was reduced after 3 and 7 days of delmopinol use, with coccoid cells as the predominant morphotype. Plaque maturity, characterized by the appearance of corncob formations and high numbers of different morphotypes, was not observed on the delmopinol specimens, in contrast to the placebo specimens. The study shows that topical application of 0.5% delmopinol HCl delays and interferes with dental plaque maturation.