The effect of chlorhexidine mouthrinses on the human oral flora

Clinical effects of pulsed oral irrigation with 0.2% chlorhexidine digluconate in patients with adult periodontitis

The aim of this study was to investigate the effects of using 0.2% Chlorhexidine digluconate in an pulsated jet irrigator by patients as part of their daily dental home-care measures. After initial assessment, 16 patients diagnosed as having adult periodontitis received scaling and polishing together with advice on the subgingival use of a pulsated jet oral irrigator with which they were supplied. 8 patients having 293 active sites with probing depths equal to or in excess of 4 mm used 0.2% chlorhexidine digluconate (CHX) in the oral irrigator, 2 x daily for 56 days. The other group of 8 patients with 253 active sites over 4 mm used a placebo as the irrigating solution. A modified dichotomous plaque index (MPI), gingival bleeding index (GBI) and probing pocket depths (PPD) were assessed on days 0, 28 and 56. Within-group comparisons showed that the CHX regime reduced MPI, GBI and PPD significantly but that the placebo group (PG) only achieved a significant reduction in the PPD. Between-group comparisons showed that the use of 0.2% CHX as an irrigant was significantly more effective than the placebo solution at reducing all the clinical parameters studied. The patients found the oral irrigator easy and pleasant to use, although all the CHX group developed staining to a varying extent. This double blind study demonstrated that 0.2% CHX used 2 x daily in an oral irrigator was effective at reducing plaque deposition, periodontal inflammation and probing pocket depths. The effects of using lower concentrations of chlorhexidine digluconate in this regime need to be investigated.

The effect of a chlorhexidine rinse on the incidence of alveolar osteitis following the surgical removal of impacted mandibular third molars

A prospective randomized double-blind placebo-controlled study was conducted with 139 patients (278 bilaterally impacted mandibular third molars) to determine the effect of a perioperative 0.12% chlorhexidine gluconate rinse on the incidence of alveolar osteitis following surgical removal of impacted mandibular third molars. A statistically significant 60% reduction in the incidence of alveolar osteitis was obtained in the chlorhexidine group compared with the placebo group. In most subgroups analyzed, chlorhexidine was associated with at least a 50% reduction in alveolar osteitis compared with control groups.

Therapeutic effects of daily or weekly chlorhexidine rinsing on oral health of a geriatric population

The effects of a chlorhexidine rinse on salivary Streptococcus mutans, Lactobacillus, and Candida albicans counts and on periodontal conditions (gingival index, plaque index, pocket depths) were studied in 42 elderly subjects. Under supervision, they rinsed either daily or weekly for 6 weeks with a 0.12% chlorhexidine solution (Peridex). Saliva samples were taken for chemical and microbiologic examinations, and periodontal conditions were assessed at baseline, week 6, and 6 weeks after final rinse. Significantly lower S. mutans counts were found at week 6 for both rinsing groups (p less than 0.001). Lactobacillus and Candida counts were also generally lower at week 6, with the clearest improvement among persons with the highest counts of bacteria and yeast. Periodontal conditions were improved at week 6 (p less than 0.001) in both groups. Such improvements were not maintained 6 weeks after the rinsing regimen was completed. At baseline poor oral conditions were noticed, which placed most of the subjects at risk for tooth decay and periodontal disease. Without any other dental procedures but daily or weekly supervised rinsing, oral conditions were improved and this risk was reduced. Daily rinsing was not superior to weekly rinsing with 0.12% chlorhexidine.

Effects of chlorhexidine spray on plaque and gingival health in institutionalized persons with mental retardation

In this study, eight institutionalized males received a 0.12% chlorhexidine gluconate spray twice daily. A second group of eight males received a placebo spray in the same manner. The results indicated that pump-administered chlorhexidine spray can effectively reduce plaque and gingivitis in patients with mental retardation who are unable to brush their own teeth.

The use of an oxidising mouthwash to reduce staining associated with chlorhexidine. Studies in vitro and in vivo

Discolouration of the teeth, tongue and dental restorative materials associated with the use of cationic antiseptics is still the limiting factor in long-term usage of antiplaque agents such as chlorhexidine. Oxidising agents have been used successfully to remove dental stain in animals, but products and regimens have not been evaluated in humans. These pilot studies in vitro and in vivo assessed a long-established oxidising mouthwash, based on peroxyborate, for stain removal from teeth and acrylic. The laboratory studies measured chlorhexidine tea stain removal from tooth and acrylic specimens. The oxidising agent markedly reduced staining on specimens. In a short-term clinical experiment, dental staining was forced over a 2 1/2-day period by reciprocal chlorhexidine and tea rinsing. 5 rinses with the oxidising mouthwash during the next 1 1/2 days dramatically reduced staining compared with water after rinses. Additionally, a single rinse with peroxyborate following the 5 water after rinses, again considerably reduced the residual staining. Effects on tongue staining were less impressive. Both experimental models produced findings consistent with those from the animal model. The results suggest proprietary oxidising mouthwashes could have a place in the control of dental stain associated with the use of chlorhexidine. Further studies to evaluate such products in a more conventional chlorhexidine regimen are indicated.

The efficacy of chlorhexidine gel in reduction of Streptococcus mutans and Lactobacillus species in patients treated with radiation therapy

Xerostomia may develop in patients with cancer who receive radiotherapy that includes the salivary glands in the field. These patients are at high risk of rampant dental caries. Streptococcus mutans and Lactobacillus species have been associated with dental caries. Quantitative counts of these organisms demonstrated high caries risk due to streptococci in 66% and due to lactobacilli in 100% of patients studied. Use of chlorhexidine rinse was shown to reduce S. mutans counts 1.1 logs and lactobacilli 1.1 logs. The use of chlorhexidine gel resulted in a reduction of S. mutans 1.2 logs and lactobacilli 2.2 logs. In the subjects using the rinse, caries risk due to streptococci was reduced to low levels in 44% and due to lactobacilli in only one subject, with reduction to moderate risk in one third and no change in risk in the remaining patients. The use of chlorhexidine gel was found to reduce the caries risk associated with streptococci to low levels in all patients, and the risk associated with lactobacilli to low and moderate risk in two thirds of patients.

The effect of some chlorhexidine-containing mouthrinses on salivary bacterial counts

A number of chlorhexidine mouthwashes are available commercially which differ in formulation and regimen of use. As a comparative measure of antimicrobial persistence, this study evaluated the effect of 4 chlorhexidine mouthwash formulations on salivary bacterial counts after a single rinse. The study was a randomised single-examiner blind 5-way crossover investigation employing a panel of 10 young healthy human volunteers. The 0.12% and 0.2% commercial formulations when rinsed according to the respective manufacturers instructions produced similar large and prolonged reductions in salivary bacterial counts during the 7-h period. A 0.1% formulation also commercially available produced minimal effects on salivary bacterial counts and was little different to the saline rinse. A reformulated 0.1% rinse, not commercially available at the time of the study, produced significant salivary bacterial count reductions over the 7-h period albeit to a lesser degree of magnitude than to the 0.2% and 0.12% rinses. The results were consistent with comparative plaque inhibitory studies of the formulations and suggest that the method is a quick and simple way of screening products for antimicrobial and antiplaque potential.

Effects of a chlorhexidine gluconate oral rinse on the incidence of alveolar osteitis in mandibular third molar surgery

Alveolar osteitis (dry socket) continues to be a frequent sequela of third molar surgery. Chlorhexidine 0.12% used as an oral rinse has been reported to reduce the incidence of dry socket. This study compares the effectiveness of 0.12% chlorhexidine used as a preoperative rinse and immediate postextraction irrigant with 1) similarly used 0.05% cetylpyridium, preoperative chlorhexidine rinse and postextraction saline irrigation, and 2) only postextraction irrigation with normal saline in the reduction of alveolar osteitis in mandibular third molar extractions. The results indicate that chlorhexidine and cetylpyridium were no more effective in the reduction of alveolar osteitis than postextraction irrigation with normal saline.

Comparative antiplaque activity of sanguinarine and chlorhexidine in man

This clinical investigation examined the effect of a sanguinarine extract on bacterial plaque growth in man. Three different mouthrinses were examined: (i) Veadent containing 0.03% sanguinarine and 0.2% zinc chloride (test rinse); (ii) a vehicle solution containing all the excipients of Veadent except the 0.03% sanguinarine (control rinse); (iii) Hibident a 0.2% chlorhexidine digluconate formulation (positive control rinse). The trial in which 12 dental students participated, was designed as a single-blind, cross-over study. During 3 experimental periods of 18 days, the participants refrained from mechanical oral hygiene and rinsed twice a day with one of the above mentioned solutions. Between experimental phases, a wash-out period of 11 days was instituted. In each subject, 4 teeth were randomly selected for assessment. Clinical evaluations were performed at days 1 (0, 4, 8, 12 hours), 2, 4, 11 and 18. The plaque on the buccal surfaces of the selected teeth was disclosed with neutral red 0.05% and colour slides taken. The % of the tooth surface covered with plaque was calculated planimetrically from these colour slides. The present results show an excellent anti-plaque effect with Hibident, a very small effect with Veadent and a negligible effect with the vehicle solution without the sanguinarine. These findings would suggest that the Veadent mouthrinse would have at most only a limited role as a plaque inhibitor.

Chlorhexidine prophylaxis for chemotherapy- and radiotherapy-induced stomatitis: a randomized double-blind trial

Patients receiving cytotoxic antineoplastic therapy often have treatment-associated stomatitis. A 0.12% chlorhexidine digluconate mouthrinse was evaluated (15 ml, three times a day) in a prospective, double-blind randomized trial as prophylaxis against cytotoxic therapy-induced damage to oral soft tissues. Seventy subjects, forty inpatients receiving high-dose chemotherapy and thirty outpatients receiving high-dose head and neck radiation therapy, were evaluated. Chlorhexidine mouthrinse significantly reduced the incidence of oral mucositis in the chemotherapy group on day 14 (p less than 0.02) and at 1 week follow-up on day 28 (p less than 0.002). Mucositis in the patients undergoing chemotherapy who received chlorhexidine also resolved more rapidly. Mucositis severity was significantly less compared to the control chemotherapy group on day 14 (p less than 0.03), day 21 (p less than 0.04), and on 1 week follow-up (p less than 0.02). Concomitant trends in the reduction in oral streptococci and yeast were noted in the chemotherapy group receiving chlorhexidine mouthrinse. Although no differences were observed in oral mucositis between the control and chlorhexidine groups of patients undergoing high-dose radiotherapy, similar reductions of oral microflora to those seen in the chemotherapy population were also noted for patients undergoing radiation therapy who received chlorhexidine. Although generally not significant, some increase in gram-negative bacilli was noted in the chlorhexidine-treated patients in both the chemotherapy and radiotherapy groups, but there was no correlation with increased systemic infection. Prophylactic chlorhexidine mouthrinse reduces oral mucositis and microbial burden in patients with cancer undergoing intensive chemotherapy.

Chlorhexidine rinse in prevention of dental caries in patients following radiation therapy

Patients who receive cancer radiotherapy, which compromises salivary gland function, may develop xerostomia. These patients are at increased risk to develop rampant dental caries. Streptococcus mutans and species of lactobacillus have been associated with dental caries. Quantitative counts of these organisms demonstrated high caries risk in 85% of patients studied. The use of chlorhexidine rinse to reduce the counts of S. mutans and lactobacillus was studied. A modest reduction in S. mutans was seen, but little effect was demonstrated on lactobacillus counts. Caries activity was shown to be related to lactobacillus count.

Direct measurement of the bactericidal effect of chlorhexidine on human dental plaque

The purpose of the present study was to determine by means of a fluorescence test the ratio between vital and dead bacteria in dental plaque before and after 0.1% chlorhexidine rinses. Plaque was stained by fluoresceindiacetate (FDA), which gave a green color to the living micro-organisms, and by ethidiumbromide (EB), which introduced a red color into the nucleic acids of the dead bacteria. 1-, 2- and 3-day-old undisturbed plaque harbored 80 to 85% living micro-organisms. 1 h after chlorhexidine use, this % was reduced to a plateau of 19 to 34% of vital bacteria present in the sampled plaque. Between 6 and 8 h later, this % rose towards its original value. This study has shown that FDA/EB staining provides a method for direct measurement of bacteria vitality in dental plaque and, as such, can be of great value for testing the efficacy of various antiplaque agents.

Effect of chlorhexidine rinsing on the oropharyngeal ecology in patients with head and neck cancer who have irradiation mucositis

Oral flora is thought to contribute to irradiation mucositis in patients with head and neck cancer. Neglect of oral hygienic care may also contribute to mucositis. The purpose of this prospective, randomized, placebo-controlled, double-blind study was to evaluate the effect of chlorhexidine 0.1% mouthrinses on oral flora and irradiation mucositis. This study included 30 patients with head and neck cancer who had comparable irradiation portals. One group (N = 15) rinsed four times daily with chlorhexidine 0.1%, the other group (N = 15) with a placebo. The oral flora was cultured (oral washing technique) twice before and three times per week during the period of radiotherapy. On the same days, the severity of mucositis was determined. The colonization index of viridans streptococci was significantly reduced only after 5 weeks of chlorhexidine 0.1% treatment. The colonization patterns of Candida species, Streptococcus faecalis, staphylococci, and Enterobacteriaceae, Pseudomonadaceae, and Acinetobacter species were not influenced by 5 weeks of use of chlorhexidine rinses when compared with the placebo. No differences were seen between the two study groups in the development and severity of mucositis. In conclusion, suppression of oral flora and a lowering of the severity of mucositis by means of disinfecting mouthrinses were not successful.

The effect of chlorhexidine irrigation on the incidence of dry socket: a pilot study

A pilot study was conducted to measure the reported incidence of dry socket following pre-operative irrigation and mouthrinsing with either 0.2% (w/v) chlorhexidine gluconate or normal saline or with no irrigation (control). Three hundred and twenty-four patients presenting for the single extraction of a lower premolar or molar under local anaesthesia were divided into three equal groups; no irrigation, irrigation with saline and irrigation with a 0.2% (w/v) chlorhexidine gluconate solution. After administration of the local anaesthetic agent, 10 ml of the test solutions were applied to the gingival crevice using a blunted needle. The solutions were retained in the patients mouth for 2 min following irrigation. Pre-operative irrigation of the gingival crevice and mouthrinsing with 0.2% (w/v) chlorhexidine gluconate significantly reduced the number of dry sockets. There was no significant reduction in the number of dry socket cases following irrigation and rinsing with normal saline. The irrigation technique, using 0.2% (w/v) chlorhexidine gluconate is safe, inexpensive, easy to apply and can be recommended for routine use in dental practice, to reduce the incidence of dry socket.

Mouthrinses in "experimental gingivitis" studies

The experimental gingivitis study design is a frequently used clinical model for the evaluation of the effects of antimicrobial agents on developing plaque and gingivitis. In individuals who at the start of the experiment have clean teeth and healthy gingivae and who use a mouthrinse containing the test agent as the only tooth cleaning measure during a period of 14-21 days, the anti-plaque and anti-gingivitis potential of the agent can be properly evaluated. The present paper describes different designs of experimental gingivitis studies for the evaluation of chemotherapeutic agents used to control supragingival plaque formation. Findings reported in the literature with respect to the effects obtained by various antimicrobial compounds are also reported.

The mechanism of action of chlorhexidine. A study of plaque growth on enamel inserts in vivo

Controversy exists concerning the mode of action of chlorhexidine in plaque inhibition. This study attempted to determine whether an oral reservoir of chlorhexidine was necessary for plaque inhibition. Plaque growth on enamel under the influence of topically applied or rinsed chlorhexidine was closely monitored by clinical scoring, bacterial culturing and scanning electron microscopy. Thus, 3 subjects wore removable acrylic appliances containing enamel inserts. In the first regimen, inserts on one side of the appliances were exposed to 0.2% chlorhexidine and on the other, water for 1 min twice a day for 14 days. In the second regimen, subjects rinsed with 0.2% chlorhexidine for 1 min twice a day for 14 days with the appliances in situ. Results demonstrated that plaque growth assessed by the 3 study methods was very small on chlorhexidine-treated inserts by comparison with water-treated specimens. Importantly, inserts treated with chlorhexidine topically or by rinsing could not be distinguished by any method of evaluation. It is concluded that chlorhexidine achieves plaque inhibition as a result of an immediate bactericidal action during the time of application and a prolonged bacteriostatic action as a result of adsorption to the pellicle coated enamel surface. Consistent with other clinical studies, it is apparent that a progressively desorbing oral reservoir of antiseptic is not the mechanism by which chlorhexidine achieves plaque inhibition on teeth.

Antimicrobial agents in the prevention and treatment of periodontal diseases

It has been estimated that there are more than 400 diseases affecting the oral cavity. In terms of prevalence, however, the major public health problems are caries and periodontal disease. Although these two destructive entities are completely different in many respects, they share a common denominator: the initial lesions are brought about by an aggregate of bacteria known as plaque. This article discusses chemical control of plaque in the treatment of gingivitis and antimicrobial control of subgingival plaque in the treatment of periodontitis. The authors address the use of antibiotics in the treatment of localized juvenile periodontitis, the ideal properties of antiplaque agents, and adjunctive subgingival application of antimicrobial agents.

The antibacterial effect of toothpastes on the salivary flora

Both past and presently available toothpastes contain potential antimicrobial agents which could have a beneficial effect in the prevention of plaque and gingivitis. If these preparations were to be effective clinically, some effect on salivary bacteria would also be expected. This cross-over study measured salivary bacterial counts and the presence or absence of residual antibacterial activity in saliva following tooth brushing with 7 commercially available toothpastes, and moreover, compared their effect with that produced by a chlorhexidine gel. Generally, all toothpaste products produced a reduction in aerobic, anaerobic and streptococcal counts with a hexetidine containing toothpaste producing the largest and longest lasting reduction. In contrast, an enzyme containing toothpaste and an amine fluoride toothpaste, had little effect on bacterial counts. The chlorhexidine gel produced the largest reduction in salivary counts, which was evident for at least 5 h following brushing. Residual antibacterial activity in saliva was only evident immediately following brushing with the hexetidine toothpaste, but for the chlorhexidine gel, was present up to 90 min following brushing. The findings of this study have illustrated the limited antibacterial activity of presently available toothpastes on the salivary flora compared to chlorhexidine, and as such, would tend to question the relative benefit of toothpaste in preventing periodontal disease through an antimicrobial effect.

Therapeutic use of chlorhexidine in bone marrow transplant patients: case studies

Patients undergoing cytotoxic chemotherapy and radiation therapy often experience severe oral complications during and after treatment despite supervised oral hygiene and conventional antimicrobial regimens. The antimicrobial compound chlorhexidine is an effective topical prophylactic agent against oral mucositis and candidiasis. Oral mucositis developed in four patients who underwent bone marrow transplantation; the condition was severe enough to prompt use of chlorhexidine. In each case, there was clinical resolution of mucositis and a concomitant decrease in the oral microbial burden 1 week after chlorhexidine use began. This strongly suggests that, in addition to its value in protecting these severely immunocompromised patients from oral infection, chlorhexidine also offers a therapeutic benefit in the resolution of existing oral infections and of mucositis.

Chlorhexidine for prophylaxis against oral infections and associated complications in patients receiving bone marrow transplants

Intensive chemoradiotherapy damages the mucosal barrier of the mouth and throat and is often associated with severe oral inflammation and infection. This study examined the use of a 0.12% chlorhexidine gluconate mouthrinse for prophylaxis against oral complications in patients receiving bone marrow transplants. Use of chlorhexidine mouthrinse produced reductions in oral soft tissue disease and oral microbial burden, including a significant decrease in oral mucositis and Candida infections. The advantage for patients undergoing intensive antineoplastic therapy, and potentially for other immunocompromised patients susceptible to oral infections, was studied.

Antimicrobial properties of 2 aliphatic amines and chlorhexidine in vitro and in saliva

The surfactants tetradecylamine, hexadecylamine and chlorhexidine have been compared with regard to their ability to inhibit microbial growth. Antibacterial activity was assessed by tube dilution methods. Tetradecylamine and chlorhexidine were similar in antibacterial activity, being effective at low concentrations against most organisms tested. Hexadecylamine also inhibited growth but at higher concentrations. Viable counts of salivary organisms were monitored in volunteers over 48 h after one rinse with the agents. The initial reduction in numbers of total viable salivary bacteria and streptococci by tetradecylamine and of streptococci by hexadecylamine had disappeared 3 h after a single mouth rinse, but the reduction in numbers of all salivary bacteria by chlorhexidine was more prolonged.

Oral implantation of Streptococcus mutans in man with and without prior chlorhexidine mouthrinses

Oral implantation of streptomycin resistant S. mutans was enhanced when chlorhexidine mouthrinses were applied before implantation. The difference in recovery of implanted bacteria between implantations with and without prior chlorhexidine mouthrinses was significant 9 days (P less than 0.05), 15 days (P less than 0.05) and 28 days (P less than 0.01) after implantation. After 28 days implanted bacteria were no longer detected in any of the 20 test subjects when chlorhexidine was not used prior to implantation, but persisted in 11 subjects when chlorhexidine was used.

Chlorhexidine. An adjunct to periodontal therapy

Chlorhexidine is an effective antimicrobial agent. Its application can enhance periodontal therapy. The pharmacology of chlorhexidine and suggestions for its use are outlined. In addition, its potential for inducing cancer and bacterial resistance are discussed.

A review of the literature on use of chlorhexidine in dentistry

In addition to its plaque-inhibiting effect, chlorhexidine possesses other properties beneficial for use in dentistry. These effects are outlined, and specific recommendations are given regarding chlorhexidine's use by general practitioners. The side effects of long-term use, such as staining, and the availability of chlorhexidine also are discussed.

Oral complications of acute leukemia: prophylactic impact of a chlorhexidine mouth rinse regimen

The prophylactic value of twice-daily mouth rinses with a solution of 0.1% chlorhexidine gluconate in minimizing oral complications during remission-induction chemotherapy was tested in sixteen patients with acute myeloblastic leukemia. The study design was double blind with a placebo control. Standardized measurement indices were employed to assess the dental plaque levels and the degree of gingivitis and mucositis during remission-induction. The treatment group demonstrated superior oral health on the basis of each of these measurement parameters. A moderate increase in tooth staining was observed in the treatment group. The results also suggested the potential value of chlorhexidine mouth rinses in the prophylaxis of oral candidiasis in the myelosuppressed patient.

Oral colonization and susceptibility testing of Pseudomonas aeruginosa oral isolates from cystic fibrosis patients

Microbial samples from the oral cavities of cystic fibrosis (C.F.) patients and 20 age-matched normal control subjects were characterized. Mucoid variant Pseudomonas aeruginosa was isolated from the tongue, buccal mucosa, and saliva of C.F. patients only. Analysis of the data suggests that the oral cavity is a potential reservoir for this organism. Aspiration and cross-contamination from this reservoir may be important in perpetuating chronic pulmonary infection in C.F. patients. Susceptibility testing was performed on 20 mucoid variant P. aeruginosa oral isolates obtained from the patients according to standardized broth dilution procedures. The in vitro antimicrobial effects of sodium fluoride, stannous fluoride, and chlorhexidine were measured. Analysis of the data suggests that clinically safe and achievable levels of chlorhexidine and stannous fluoride may be antimicrobial.

Current status of periodontal dressings

A comprehensive review of periodontal dressings is presented. The rationale for the application of dressings, their advantages and disadvantages are described. Tissue reactions to dressings and the therapeutic and adverse effects of antimicrobial agents used in dressings are discussed. The present status and value of a surgical dressing is critically assessed in view of recent studies which indicate that the routine use of dressings in postsurgical care may be either unnecessary or undesirable.

Chemotherapy and periodontal disease--a review

Periodontal diseases are common, inflammatory infections of the mouth of microbiological etiology. Therapy traditionally focuses on professional tooth cleaning and debridement. Recent research has investigated the efficacy of antibiotic therapy, as well as the use of various other agents. Although protocols still are being developed, pharmacists can expect increasing use of these medications by dentists in the future.

Dental bacterial plaque

The literature on the subject of dental bacterial plaque is extensive. In spite of considerable research, the mode of its formation together with the variability in bacterial content requires further clarification. Mechanical methods of plaque control are effective but limited in a population sense. Of the numerous chemotherapeutic agents in plaque control, chlorhexidin appears the most effective.

Effect of a new anti-plaque agent (CK-0569A) on developing plaque and gingivitis in man

This study investigated the effect of 1,4-bis[3-(n-hexylcarbamylguanidine)propyl]piperazine dimethanesulfonic acid salt (CK-0569A), used as a mouthrinse, on the development of plaque and gingivitis in humans. Fourteen dental students participated in a double-blind cross-over study. At the start of each of the two 14-day periods of mouthrinsing (one period with CK-0569A and one period with a placebo solution) the participants were examined for the presence of plaque (P1I) and gingivitis (GI). In addition, supragingival plaque samples were obtained and analyzed by darkfield microscopy. Clinical examination of plaque and gingivitis was repeated 4, 7 and 14 days after the start of the no-toothbrushing periods. Bacterial samples were obtained after 7 and 14 days of trial. The results demonstrated that a mouthrinse containing CK-0569A prevented the colonization of motile + curved rods and spirochetes in developing plaque. Furthermore, rinsing twice daily with 0.1% solution CK-0569A significantly reduced the amount of dental plaque formed and retarded the development of gingivitis.

Plaque control with chlorhexidine and D-301, a quaternary ammonium compound

Eighteen female dental hygiene students took part in a double-blind, crossover clinical trial of equimolar (2.2 mmol) rinsing solutions of D-301, a quaternary ammonium compound and chlorhexidine digluconate, Rinsings were partly supervised, test periods were 7 days (5 days without oral hygiene) with a 1-week interval. Plaque formation was significantly reduced by both test solutions versus the control; on not precleaned tooth surfaces plaque formation was equally inhibited by the chlorhexidine and D-301 mouthrinses. On precleaned surfaces D-301 significantly inhibited plaque formation compared with the control rinse, but was less effective than chlorhexidine. There was no significant change in the PBI, a measure of gingival inflammation, during any of the test period. Staining of teeth and tongue was judged as equal after chlorhexidine and D-301 use. Reports of taste and gastric disturbances were minimal but more frequent during the D-301 test period.

The effect of single morning and evening rinses of chlorhexidine on the development of tooth staining and plaque accumulation. A blind cross-over trial

A dietary aetiology for tooth staining associated with the use of chlorhexidine has been postulated. The time related activity of chlorhexidine would therefore suggest that evening rinsing would result in less staining than morning rinsing. This study measured tooth and tongue staining and plaque accumulation in a group of 18 volunteers, rinsing once at night or once in the morning with chlorhexidine in a blind cross-over design. Beverage intake during two 10-day periods was prescribed. Significantly more tooth staining, but not tongue staining, was seen with morning rinsing. Plaque accumulation showed a trend to more plaque with morning rinsing, which was not significant. The findings would be consistent with a dietary aetiology for tooth staining. However, these results emphasise the considerable duration of activity of chlorhexidine on surfaces in the oral cavity and the theory of progressive desorption of chlorhexidine from the tooth surface is questioned.

A comparison of cord gingival displacement with the gingitage technique

Fifteen young adult dogs were divided into three groups representing 0, 7- and 21-day healing periods. Randomly selected cuspid teeth were used to compare cord gingival displacement and gingitage techniques for subgingival tooth preparation and impression making. Clinical and histologic measurements were used as a basis for comparison. Results indicate that (1) the experimental teeth were clinically healthy at the beginning of the experiment, (2) clinical health of the gingival tissues was controlled throughout the course of the experiment, and (3) within this experimental setting, there was no significant difference between the cord gingival displacement technique and the gingitage technique.

The inhibitory effect of chlorhexidine digluconate on dental plaque formation. A scanning and transmission electron microscope study

The purpose of this study was to determine the effect of chlorhexidine digluconate mouthrinses on the development of dental plaque in man. The dental plaques were formed on strips of triacetylcellulose film (TAC), which were attached to the lingual surfaces of the mandibular incisors by silk suture thread on 20 human volunteers. Differences in the degree of plaque formation on TAC films after 2, 4 and 24 hours were observed in placebo vs. chlorhexidine treated samples using both scanning and transmission electron microscopy. It was found that (1) solutions containing chlorhexidine digluconate and lactic aluminum have an inhibitory effect of the development of dental plaque on the TAC film as evaluated by electron microscopy, (2) the TAC film was a convenient model for the study of early dental plaque formation by electron microscopy, (3) the three types of pellicle reported by Tryggve Lie (1977) were also observed, (4) the method enabled evaluation of the bacterial accumulation of TAC films. After 2 hours, there was no visible difference in the bacterial accumulations on placebo or chlorhexidine treated films. After 4 and 24 hours considerable differences were observed.

Comparison of the in vivo and in vitro antibacterial properties of antiseptic mouthrinses containing chlorhexidine, alexidine, cetyl pyridinium chloride and hexetidine. Relevance to mode of action

A study was carried out to compare the antibacterial properties of four cationic antiseptics, three of which are available as commercial mouthrinse preparations. Minimum inhibitory concentrations for alexidine, cetyl pyridinium chloride, chlorhexidine gluconate and hexetidine against a range of standard test organisms, were determined by tube dilution. Similar values for Oxford staphylococcus were then obtained in Dubos medium to which protein as yeast, or food extract, or serum was added in doubling dilutions to 16%. Salivary bacterial counts after a single rinse with the antiseptics or water throughout the day were measured in 10 subjects together with the duration of any residual antiseptic activity in the saliva. All antiseptics were effective at low concentrations against the organisms tested but the minimum inhibitory concentration values for hexetidine were the highest. Food extract and serum markedly increased the minimum inhibitory concentration values of all antiseptics, although alexidine and hexetidine were the least affected in percentage terms. The activity of a 1% povidone iodine preparation, used for comparison, was almost completely vitiated. An immediate significant fall in salivary bacterial counts was produced by the cationic antiseptics. Return to pre-rinse levels was seen for hexetidine after 90 min, cetyl pyridinium chloride after 3 hours, alexidine after 5 hours and chlorhexidine gluconate after 7 hours. Residual salivary antibacterial activity remained to 90 min for cetyl pyridinium chloride, to 3 hours for hexetidine and alexidine and to 5 hours for chlorhexidine gluconate. The antibacterial properties measured, in particular the duration of effect in vivo, may be relevant to the anti-plaque activity of cationic antiseptics.

Comparison of the bisbiguanide antiseptics alexidine and chlorhexidine. I. Effect on plaque accumulation and salivary bacteria

A blind crossover trial was carried out to compare the effects of a 0.2% chlorhexidine gluconate mouthrinse and a 0.035% alexidine mouthrinse on plaque accumulation and salivary bacteria in a group of volunteers. The subjects refrained from all forms of oral hygiene during two 10-day periods and rinsed twice a day with the mouthwash randomly allocated to the respective period. Prerinse, day 4 and day 10 total salivary aerobic and anaerobic bacterial counts were determined during each period. Plaque scores were recorded at the end of each 10-day period. Significantly more plaque accumulated in subjects rinsing with alexidine when compared with chlorhexidine. Significant and comparable reductions in salivary bacterial counts were observed with both chlorhexidine and alexidine on day 4 and day 10 when compared with pre-rinse counts. Although at the concentrations used alexidine was less effective than chlorhexidine, it may be of value as a short-term adjunct to oral hygiene.

Chemical inhibition of plaque

Attempts to control plaque by chemical means using enzymes, antibiotics and antiseptics are reviewed. Enzymes such as mucinase, dehydrated pancreas, enzymes of fungal origin, dextranase and mutanase showed limited clinical success despite promising in vitro and animal studies. Side effects from the use of enzymes were observed. Many antibiotics have been used in attempts to control plaque and several have been successful. However, problems exist from the long-term use of such drugs which precludes their routine use as agents for controlling plaque. The biguanide chlorhexidine is the most widely used and investigated method of chemical plaque control. Many studies have been demonstrated that it will successfully control plaque. No toxic side effects have been reported from its long-term use but local side effects such as staining of the teeth do occur. The quaternary ammonium compounds have at present no advantages over the biguanides and require more frequent usage to achieve the same degree of plaque control as chlorhexidine.

Effect of blood group active micro-organisms on the ABO grouping of human whole saliva

Three saliva samples with false positive ABO grouping results were assayed for blood group active organisms, using a variety of selective media to isolate representative strains from the salivary microflora. Eight out of 40, 8 out of 40 and 4 out of 30 strains from the three samples, respectively, showed blood group activity, which correlated well with the false positive specificities of the saliva samples. In all cases the false reaction only lasted a few days. Investigation of one of these samples before and after the appearance of the false positive activity yielded only one out of 40 blood group active organisms, using the same methods. Similar investigation of two "normal" saliva samples found none out of 40 and one out of 40 blood group active organisms, respectively. It is concluded that occasional false positive ABO grouping reactions of saliva samples are probably caused by the presence of unusually high numbers of blood group active micro-organisms, due to disturbances in the ecological balance of the salivary microflora.

Influence of oral hygiene measures on the development of alveolitis sicca dolorosa after surgical removal of mandibular third molars

This study was carried out in order to investigate the prophylactic effect of plaque control on the development of alveolitis sicca dolorosa (ASD). Sixty patients took part in the investigation. The patients in the test group had their teeth polished 5 days preoperatively and then used a 0.2% aqueous solution of chlorhexidine digluconate as a mouth rinse twice a day before the operation and during the postoperative week. No special oral hygiene measures were taken in the control group. Compared with the control group, the patients in the test group had significantly less plaque on their teeth on the day of operation (P less than or equal to 0.001). One patient in the test group developed ASD, while there were five cases of ASD in the control group. The results indicated that plaque control may be a possible way to decrease the incidence of ASD.