Activity of amine-stannous fluoride combination and chlorhexidine against some aerobic and anaerobic oral bacteria

Efficacy of Experimental Mouth Rinses on Caries-Related Biofilms in vitro

This study assessed the efficacy of tin and Polyethylenglycol (PEG-3) tallow aminopropylamine in different concentrations on Streptococcus mutans (S. mutans) biofilms to establish a new screening process for different antimicrobial agents and to gain more information on the antibacterial effects of these agents on cariogenic biofilms. Isothermal microcalorimetry (IMC) was used to determine differences in two growth parameters: lag time and growth rate; additionally, reduction in active biofilms was calculated. Experimental mouth rinses with 400 and 800 ppm tin derived from stannous fluoride (SnF₂) revealed results (43.4 and 49.9% active biofilm reduction, respectively) similar to meridol mouth rinse (400 ppm tin combined with 1,567 ppm PEG-3 tallow aminopropylamine; 55.3% active biofilm reduction) (p > 0.05), while no growth of S. mutans biofilms was detected during 72 h for samples treated with an experimental rinse containing 1,600 ppm tin (100% active biofilm reduction). Only the highest concentration (12,536 ppm) of rinses containing PEG-3 tallow aminopropylamine derived from amine fluoride (AmF) revealed comparable results to meridol (57.5% reduction in active biofilm). Lower concentrations of PEG-3 tallow aminopropylamine showed reductions of 16.9% for 3,134 ppm and 33.5% for 6,268 ppm. Maximum growth rate was significantly lower for all the samples containing SnF₂ than for the samples containing control biofilms (p < 0.05); no differences were found between the control and all the PEG-3 tallow aminopropylamine (p > 0.05). The growth parameters showed high reproducibility rates within the treated groups of biofilms and for the controls; thus, the screening method provided reliable results.

Increase in Cariogenic Bacteria after Initial Periodontal Therapy

This study examined the hypothesis of an intra-oral shift, during initial periodontal therapy, from a periopathogenic to a cariogenic flora. Seventy-one patients with periodontitis were randomly allocated to one of the following treatment strategies: (1) scaling and root planing, quadrant by quadrant, at two-week intervals (NC); (2) full-mouth scaling and root planing within 24 hrs (FRP); or (3) full-mouth disinfection within 24 hrs, including antiseptics [chlorhexidine (CHX) or amine fluoride/stannous fluoride (F) for 2 mos, or CHX for 2 mos followed by F for 6 mos (CHX+F)]. At baseline and after 2, 4, and 8 mos, bacterial samples were taken from supra- and subgingival plaque, saliva, and tongue. The detection frequencies and relative proportions of Streptococcus mutans increased in the NC and FRP groups, but decreased in the F group. In the CHX group, these species disappeared temporarily, but they disappeared for the entire 8 mos in the CHX+F group. These observations were similar for all sample locations. The periopathogens decreased in all groups. This finding confirms the abovementioned hypothesis and indicates a need for caries prophylactic regimens.

Microbiota-based Signature of Gingivitis Treatments: A Randomized Study

Plaque-induced gingivitis can be alleviated by various treatment regimens. To probe the impacts of various anti-gingivitis treatments on plaque microflora, here a double blinded, randomized controlled trial of 91 adults with moderate gingivitis was designed with two anti-gingivitis regimens: the brush-alone treatment and the brush-plus-rinse treatment. In the later group, more reduction in both Plaque Index (TMQHI) and Gingival Index (mean MGI) at Day 3, Day 11 and Day 27 was evident, and more dramatic changes were found between baseline and other time points for both supragingival plaque microbiota structure and salivary metabonomic profiles. A comparison of plaque microbiota changes was also performed between these two treatments and a third dataset where 50 subjects received regimen of dental scaling. Only Actinobaculum, TM7 and Leptotrichia were consistently reduced by all the three treatments, whereas the different microbial signatures of the three treatments during gingivitis relieve indicate distinct mechanisms of action. Our study suggests that microbiota based signatures can serve as a valuable approach for understanding and potentially comparing the modes of action for clinical treatments and oral-care products in the future.

Development of resistance of mutans streptococci and Porphyromonas gingivalis to chlorhexidine digluconate and amine fluoride/stannous fluoride-containing mouthrinses, in vitro

OBJECTIVE

The aim if this study was to determine the minimal inhibitory concentrations of chlorhexidine digluconate and an amine fluoride/stannous fluoride-containing mouthrinse against Porphyromonas gingivalis and mutans streptococci during an experimental long-term subinhibitory exposition.

MATERIAL AND METHODS

Five P. gingivalis strains and four mutans streptococci were subcultivated for 20-30 passages in subinhibitory concentrations of chlorhexidine digluconate or an amine fluoride/stannous fluoride-containing mouthrinse.

RESULTS

Pre-passaging minimal inhibitory concentrations for chlorhexidine ranged from 0.5 to 2 mg/l for mutans streptococci and from 2 to 4 mg/l for the P. gingivalis isolates. For the amine fluoride/stannous fluoride-containing mouthrinse minimal inhibitory values from 0.125 to 0.25% for the mutans streptococci and from 0.063 to 0.125% for the P. gingivalis isolates were determined. Two- to fourfold increased minimal inhibitory concentrations against chlorhexidine were detected for two of the five P. gingivalis isolates, whereas no increase in minimal inhibitory concentrations was found for the mutans streptococci after repeated passaging through subinhibitory concentrations. Repeated exposure to subinhibitory concentrations of the amine fluoride/stannous fluoride-containing mouthrinse did not alter the minimally inhibitory concentrations of the bacterial isolates tested.

CONCLUSION

Chlorhexidine and the amine fluoride/stannous fluoride-containing mouthrinse are effective inhibitory agents against the oral bacterial isolates tested. No general development of resistance against chlorhexidine or the amine fluoride/stannous fluoride-containing mouthrinse was detected. However, some strains showed potential to develop resistance against chlorhexidine after prolonged exposure.

CLINICAL RELEVANCE

The use of chlorhexidine should be limited to short periods of time. The amine fluoride/stannous fluoride-containing mouthrinse appears to have the potential to be used on a long-term basis.

In vitro antimicrobial and anticancer potential of hinokitiol against oral pathogens and oral cancer cell lines

Hinokitiol is a natural component isolated from Chamacyparis taiwanensis. It has anti-microbial activity, and has been used in oral care products. The minimal inhibitory concentration (MIC) and minimal microbicidal concentration (MMC) of hinokitiol against MRSA, Aggregatibacter actinomycetemcomitans, Streptococcus mutans, and Candida albicans were determined by the agar and broth dilution method (MIC: 40-110μM; MMC: 50-130μM); the paradoxical inhibition phenomenon (PIP) was observed in A. actinomycetemcomitans and S. mutans. The PIP can be described as microbial growth occurring in the presence of both high and low concentrations of a compound, between which microbial growth is inhibited. The PIP was confirmed using a kinetic microplate and inhibition zone methods. The PIP was also observed in MRSA. The low autolysin activity somehow correlated to the PIP positive. The cell diameter was increased in all the pathogens, and the transition was inhibited in C. albicans following hinokitiol treatment. Hinokitiol is also a potential anticancer drug. The 200μM of hinokitiol has significant antimicrobial and cytotoxic activities against oral pathogens and oral squamous cell carcinoma cell lines, respectively, and lower cytotoxic effects for normal human oral keratinocytes, indicating that hinokitiol displays a high potential for safe and effective applications in oral health care.

Clinical and microbiologic results 12 months after scaling and root planing with different irrigation solutions in patients with moderate chronic periodontitis: a pilot randomized trial

BACKGROUND

The aim of this study is to determine in a randomized trial the impact on treatment outcome after 12 months of different subgingival irrigation solutions during scaling and root planing (SRP).

METHODS

Fifty-one adult volunteers with generalized chronic periodontitis were treated by full-mouth SRP using 0.9% sodium chloride, 0.12% chlorhexidine digluconate, or 7.5% povidone-iodine for subgingival irrigation during SRP. Before SRP and after 3 and 12 months, probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were recorded. Subgingival plaque samples were analyzed for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola.

RESULTS

PD, CAL, and BOP were significantly improved in all groups after 12 months (P <0.001 to P = 0.044). No significant differences were seen among the groups for all sites and sites with 4 to 6 mm PD at baseline. The povidone-iodine group had the highest clinical improvements. The counts of A. actinomycetemcomitans and P. gingivalis were significantly reduced after 12 months (P = 0.045 and P = 0.002) using povidone-iodine. Significant differences between the groups were seen after 3 months for A. actinomycetemcomitans and P. gingivalis, and after 12 months for T. forsythia.

CONCLUSIONS

No differences were seen among the groups in the clinical results after 12 months. Regarding the microbiologic results, a slight benefit seemed to derive from the use of povidone-iodine.

Effect of amine fluoride-stannous fluoride preparations on oral yeasts in the elderly: a randomised placebo-controlled trial

OBJECTIVES

Oral yeast infections are an emerging problem among medically compromised and frail elderly. Antifungal drug resistance is also increasing because of an increase in non-albicans Candida strains in these populations. We therefore set out to study, in the randomised-controlled trial setting if the use of a topical amine fluoride-stannous fluoride combination (AmF-SnF2) could control oral Candida growth in the elderly. The hypothesis was based on earlier findings showing that in vitro this combination had antifungal efficacy.

METHODS

A total of 194 nursing home residents were randomised to receive either the test mouth rinse and toothpaste or a placebo twice daily for 8 months. Of these, 136 completed the trial. Saliva samples were taken using the oral rinse method, cultivated and the strain level identified with routine microbial methods. Compliance and use of preparations was assessed by a nurse.

RESULTS

Significantly at the end of the trial, less mucosal lesions were observed in the test group in comparison to controls. Total bacterial count decreased in both the groups during the trial. Candida albicans was the most prevalent strain detected both at baseline and 8 months later. Only a few subjects carried non-albicans strains. The AmF-SnF2 did not significantly affect mean oral Candida counts, but median Candida counts were reduced in the AmF-SnF2 group while an increase was seen in the placebo group. However, the differences observed were not statistically significant. Compliance among the regular elderly users slightly increased during the trial for both the groups.

CONCLUSION

The number of subjects with high Candida counts decreased in the AmF-SnF2 group. Hence, the fluoride combination might be useful as a support therapy for oral candidiasis. Prevalence of non-albicans Candida strains was low in this population.

Effects of fluorides on Candida albicans

AIMS

To assess whether a short exposure of Candida albicans to commonly used fluorides would affect growth, cell surface hydrophobicity, and adherence to buccal epithelial cells.

METHODS

Candida albicans ATCC 90028 and 11 clinical isolates were used. Minimal inhibitory concentrations (MICs) of sodium fluoride (NaF) and of an amine fluoride / stannous fluoride combination (AmF / SnF2) were determined. Yeasts were exposed to MICs of tested agents for 1 h. Subsequently, their growth was recorded spectrophotometrically. Their cell surface hydrophobicity was assessed with n-hexadecane. Adherence to buccal epithelial cells was determined microscopically. Phosphate buffered saline (PBS) and chlorhexidine digluconate (CHX) served as controls. All results were analyzed by one-way ANOVA.

RESULTS

MICs of AmF / SnF(2) and CHX varied between 1 and 4 microg ml(-1), whereas those of NaF were 15 000 microg ml(-1). Statistically significant growth inhibition was detected after AmF / SnF(2) (OD(24 h) +/- SD 0.457 +/- 0.059) and CHX (0.175 +/- 0.065) in comparison with PBS (0.925 +/- 0.087) and NaF (0.813 +/- 0.081). All strains demonstrated uniform behavior. Only minor changes in cell surface hydrophobicity and adherence to buccal epithelial cells (BEC) were detected.

CONCLUSION

Growth inhibition of AmF / SnF(2) was comparable with that of CHX whereas NaF had a weaker effect. Exposure to the fluorides did not seem to alter the cell surface hydrophobicity nor adherence to BEC.

In vitro antifungal effect of amine fluoride-stannous fluoride combination on oral Candida species

OBJECTIVE

The combination of amine fluoride and stannous fluoride (AmF/SnF2) was, by chance, found to be antifungal in a clinical trial. This study investigated its effect on pathogenic Candida species with the hypothesis that the antifungal action on different species is variable.

MATERIALS AND METHODS

Growth inhibition effect of Meridol mouth rinse which contains 250 ppm AmF/SnF2 was evaluated on 43 reference and clinical strains of Candida albicans, C. dubliniensis, C. glabrata, C. guilliermondii, C. krusei, C. parapsilosis, and C. tropicalis. Meridol base solution without AmF/SnF2 was used as a negative control.

RESULTS

Undiluted Meridolmouth rinse killed most study strains within a few minutes. In ascending order, C. parapsilosis, C. tropicalis, C. albicans, C. glabrata, C. krusei and C. dubliniensis showed higher resistance against AmF/SnF2 than C. guilliermondii.

CONCLUSION

AmF/SnF2 could be used as a potent adjunct to antifungal therapy for oral yeasts. Although different Candida species demonstrated variable sensitivity the most prevalent oral yeast C. albicans appeared sensitive to the AmF/SnF2 combination.

Does professional preventive care benefit from additional subgingival irrigation?

The effect of an oral irrigator (Water Pik, Intersante) with a subgingival tip (Pik Pocket Subgingival Tip, Intersante) in the reduction of gingivitis was investigated in a single-blind three-group study involving 45 volunteers (age 46.2+/-10.2). All volunteers (inclusion criteria: gingivitis or a superficial periodontitis) were examined and underwent professional tooth cleaning at the first appointment. They were then randomly distributed in three groups: one group used the irrigator with the subgingival tip once daily with just tap water, in addition to their regular oral hygiene; another group also used an herbal-based mouth rinse (Parodontax, GlaxoSmithkline) in the water of the irrigator; a third group did not use an irrigator or any irrigant and therefore served as control. All groups received professional oral care education at each appointment. The investigation period was 3 months. At baseline and after 4, 8, and 12 weeks, the plaque index (PI, scores 0-5), gingival index (GI, scores 0-3), bleeding index (BI scores 0-5), and sulcus fluid flow rate (SFFR, Periotron 6000) at the Ramfjord teeth were scored. At baseline and after 3 months, the probing depth (millimeters) was measured at six surfaces of all teeth. A significant reduction in BI, PI, GI, probing depth, and SFFR was observed within 3 months. With all volunteers, however, there was no statistically significant difference ( p>/=0.05, Wilcoxon-test, SAS 6.04) between the three groups at any time. The additional use of the Water Pik irrigator with the Pik Pocket subgingival irrigation device with or without an herbal mouth rinse showed no clinical benefit over professional education in oral hygiene alone.

One-year compliance and effects of amine and stannous fluoride on some salivary biochemical constituents and oral microbes in institutionalized elderly

Due to old age and poor general health, the institutionalized elderly have often not been used as research subjects for the investigation of oral health protocols. Because the number of elderly is increasing, they are an important target group for the development of oral hygiene aids. This trial was designed to investigate whether the institutionalized elderly could successfully use an amine-fluoride- and stannous-fluoride-containing mouthwash and toothpaste during a 12-month period. A dental hygienist visited the subjects weekly, instructed them, and recorded their self-reported compliance. Plaque and saliva samples were taken at three-month intervals. Some salivary biochemical constituents reflecting mucosal integrity were analyzed. The carrier status of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, Prevotella intermedia, and Prevotella nigrescens was studied by the polymerase chain-reaction method, and acidogenic bacteria and yeasts by dip-slide methods (Orion Diagnostica, Espoo, Finland). Of those 98 subjects originally included, 44 elderly (30 women and 14 men; mean age, 81.7 +/- 5.9 yrs) completed the trial. Their observations were positive or very positive regarding the use of mouthwash and toothpaste. The number of residents with P. gingivalis decreased statistically significantly throughout the trial, while the carrier status of the other periodontal bacteria and mutans streptococci remained on the same level. The number of subjects with high counts (> or = 10(5) cfu/mL) of yeasts decreased during the study: 26.2% at baseline, 9.1% one year later, respectively. Biochemical analyses of salivary immunoglobulins showed no effect on IgA and IgM levels, but IgG reduced significantly. Albumin and other salivary protein concentrations were found to have a decreasing tendency. Thus, the overall effect of the protocol was beneficial with regard to subjects' oral health as measured in this study. The residents were pleased to participate, but the number of drop-outs was very high, confirming the expected difficulties with the utilization of a group of frail elderly as research subjects.

Influence of growth mode and sucrose on susceptibility of Streptococcus sanguis to amine fluorides and amine fluoride-inorganic fluoride combinations

This study evaluated the susceptibility to amine fluorides (AmFs) of planktonic and biofilm cultures of Streptococcus sanguis grown with and without sucrose. Cultures were incubated with AmFs (250 mg of fluoride liter-1) for 1 min. The susceptibility of biofilms was less than that of the planktonic form and was further decreased by growth in the presence of sucrose.

Comparative study of plaque and gingivitis prevention by AmF/SnF2 and NaF. A clinical and microbiological 9-month study

This comparative clinical 9-month study was designed to examine the efficacy of amine/stannous fluoride (AmF/SnF2) (Meridol) and sodium fluoride (NaF). 150 probands with chronic gingivitis or early signs of periodontitis were divided into 3 randomised groups. Group 1 was given a NaF toothpaste and an NaF mouthrinse, group 2 AmF/SnF2 toothpaste and mouthrinse, and group 3 AmF/SnF2 toothpaste and NaF mouthrinse. The probands were examined at intervals (0, 1, 3 and 9 months) under conditions of a clinical double-blind study. The parameters recorded were the plaque index (PlI), the approximal plaque index (API), the gingival index (GI) and the mod. sulcus bleeding index (SBI). The probing depths (PD) were also measured. The composition of the supragingival plaque was evaluated by dark-field microscopy. A highly significant reduction in all clinical parameters was recorded in all 3 groups in the course of the study. The most pronounced reduction in PlI, API, SBI and PD was recorded in group 2. In the group comparison, however, no significant differences were recorded. Microbiological examination revealed a highly significant increase in cocci and a decrease in rods in all 3 groups. There was also a significant reduction in spirochetes, filaments and fusiforms in groups 2 and 3. In group 1, there was a significant fall only in fusiforms and small spirochetes. Overall, no significant difference in clinical parameters was recorded in the group comparison. However, the use of AmF/SnF2 toothpaste and mouthrinse (group 2) and, to a lesser degree, the combined use of AmF/SnF2 toothpaste and NaF mouthrinse display a favorable microbiological effect. The results from the present double-blind study reveal a reduction in gingival inflammation and supragingival plaque accumulation with a positive change in plaque flora in all groups. The reduction in potentially gingivopathogenic bacteria was slightly higher in the amine/stannous fluoride group.

Plaque bacteria counts and vitality during chlorhexidine, meridol and listerine mouthrinses

The aim of this double-blind study was to enumerate the total number of living and dead bacteria on defined tooth areas during the application of antibacterial mouthrinses. After prophylaxis, 40 students refrained from all oral hygiene measures for 3 d, during which they rinsed with a phenolic compound (Listerine), an amine fluoride/stannous fluoride solution (Meridol), 0.2% chlorhexidine (CHX) or a control solution (0.02% quinine-hydrochloride). The plaque index (P1I) was recorded at the start and the end of the investigation. Total bacterial counts (BC) and colony-forming units (CFU) of 1d-, 2d- and 3d-old dentogingival plaque were determined. The plating efficiency (PE) was calculated as a percentage of CFU/BC and the portion of vital microflora estimated by a vital fluorescence technique (VF). All groups started with a P1I approximating 0.1. On day 3, the P1I values were 1.21 in the control group and 0.51, 0.37 and 0.14 after Listerine, Meridol and CHX use, respectively. A tremendous variation existed between the numbers of viable bacteria found per mm2 on the enamel surface and day 3 (CHX: 0.2; Meridol: 300; Listerine; 6x10(4); control: 2x10(6)), while higher total numbers of bacteria were concomitantly present (CHX and Meridol: 1-2x10(4); Listerine: 2x10(5); control: 2x10(6)). Both vitality parameters PE and VF reached 92% in the control group at day 3, but only 7% after CHX use. With Meridol and Listerine, the corresponding PE values were 3% and 43%, respectively, while the VF values reached 48% and 54%. The PII, BC, CFU and PE values of the CHX and the Meridol groups differed significantly from those of the control group. In contrast, Listerine showed no difference as compared to the control rinse. Due to the strong antibacterial action of CHX and Meridol during their use, almost only dead or non-proliferating bacteria were found on the tooth surfaces. Thus, only a thin plaque could develop. As a clinical consequence, both substances showed retardation of plaque development as reflected by significantly reduced plaque indices.

Chlorhexidine susceptibilities of mutans streptococcal serotypes and ribotypes

The susceptibilities of 379 clinical mutans streptococcal isolates to chlorhexidine (CHX) were tested by agar dilution according to the standards of the National Committee for Clinical Laboratory Standards. Isolates were obtained from saliva samples of 34 young mothers who had high or moderate salivary levels of mutans streptococci at baseline. Samples were collected on three occasions, before childbirth, when each child was 6 months old, and 1 year later. Of these isolates, 50% were inhibited at 1 microgram of CHX per ml, 90% were inhibited at 2.0 micrograms/ml, and all were inhibited at 4.0 micrograms/ml. The MICs for Streptococcus mutans isolates (serotypes c, e, and f) were lower than those for Streptococcus sobrinus isolates (serotypes d and g). In some subjects, the MICs for isolates of the same serotype were different. This phenomenon was studied by ribotyping isolates (n = 45) from selected subjects (n = 7). It was found that if there were intraindividual differences in the MICs for isolates of the same serotype, then the ribotypes of these isolates were different. In order to decrease the mutans streptococcal infection risk for children, 24 mothers (test group) brushed their teeth periodically with a gel that contained 0.3% CHX digluconate and 0.2% NaF, pH 5.8, between the second and third sampling occasions. The gel was used twice a day for the first 10 days of each month. Development of resistant strains during CHX-NaF gel use was not detected. The serotype distribution of isolates from the test group after 1 year of periodic CHX-NaF gel use did not differ from that at baseline. Periodic CHX-NaF gel brushing did not lead to lower salivary mutans streptococcal counts.

One-year trial of the effect of rinsing with an amine fluoride-stannous-fluoride-containing mouthwash on gingival index scores and salivary microbial counts in lymphoma patients receiving cytostatic drugs

This double-blind study was undertaken to evaluate the effect of twice-daily use of a mouthwash containing 0.025% of fluoride as amine fluoride-stannous fluoride (AmF + SnF) or 0.05% of fluoride as sodium fluoride (NaF) on visible plaque index (VPI) and gingival bleeding index (GBI) and on some salivary micro-organisms in patients suffering from non-Hodgkin or Hodgkin lymphomas. 79 patients were allocated at random to the two mouthwash groups. Mouthwashing began at the start of cancer chemotherapy. Results relating to 45 patients who completed a 1-year rinsing protocol showed a significant decrease in VPI and GBI in the AmF + SnF group. An increase was found in the NaF group. Mean values for stimulated salivary secretion rates and buffering capacities mostly did not differ significantly from baseline values during the study. In both groups, mutans streptococci counts decreased significantly after the study began and remained low in the AmF + SnF group. No corresponding effect was seen in relation to lactobacilli and yeast counts. In the NaF group, lactobacilli counts increased significantly over a year. Significantly more patients reported adverse or unpleasant effects in the AmF + SnF group (52%) than in the NaF group (6%), although both solutions had the same colour and taste. However, all patients continued with rinsing.

In vitro susceptibility of Streptococcus mutans to chlorhexidine and six other antimicrobial agents

The susceptibility of Streptococcus mutans to chlorhexidine and to six commonly used, systemic antibacterial agents (amoxicillin, cefuroxime, penicillin, sulfamethoxazole-trimethoprim, tetracycline, and erythromycin) was studied for 424 clinical isolates from 116 children and students. The MIC of chlorhexidine for all isolates was < or = 1 micrograms/ml. No resistance to the other antimicrobial agents was detected. Although widely exposed to various antimicrobial agents, S. mutans has remained susceptible to common antimicrobial agents, most importantly to chlorhexidine.

Comparative antibacterial effects of chlorhexidine and stannous fluoride-amine fluoride containing dental gels against salivary mutans streptococci

Forty-five young adults were divided into three groups of equal size and given a professional toothcleaning (3 times during 1 wk) with dental gels containing either chlorhexidine (CHX, 1%), or a SnF2-amine fluoride (AmF) combination (F- content 1.20%). The control group received toothcleaning with a placebo gel. The study was done double blind. The number of salivary mutans streptococci was monitored for 11 wk after the gel treatment using both mitis-salivarius-bacitracin agar plates and the chairside method based on the adhesion of mutans streptococci on plastic strips (Dentocult-SM Strip mutans). Professional toothcleaning with a CHX gel was clearly most effective (P less than 0.001) but the baseline levels of streptococci returned in 11 wk. SnF2-AmF gel also reduced significantly (P less than 0.001) mutans streptococci but recolonization occurred already in 7 wk. Placebo gel, i.e. professional toothcleaning as such, did not show any statistically significant effect on the numbers of salivary mutans streptococci. None of the treatments affected the levels of lactobacilli or the total aerobic flora in saliva samples. Professional toothcleaning with a CHX gel, or with a SnF2-AmF gel, can be regarded as an alternative to the commonly used, but more patience demanding, application of gel in mouth trays at home for individuals with high caries activity.

Effect of antiseptic mouthwashes on some clinical and microbiological findings in the mouths of lymphoma patients receiving cytostatic drugs

51 patients suffering from Hodgkin's disease or non-Hodgkin's lymphoma participated in this double-blind, cross-over study in which 2 antiseptic mouthwashes were tested for their effects on various periodontal index scores and salivary microbial counts. All patients were receiving combination cytostatic treatment based on methotrexate and doxorubicin. The patients (49 +/- 14 years old, 28 men, 23 women) were allotted at random to 2 groups. One rinsed with a 0.12% chlorhexidine gluconate (CHX) solution, the other with a 0.025% amine-stannous fluoride (AmF + SnF) solution 2x daily for 2 weeks. Both groups then continued rinsing with a 0.05% sodium fluoride (F) solution for 2 weeks, before switching over to AmF + SnF or CHX, respectively. All solutions had been prepared in such a way that they had the same colour and taste. Visible plaque index and gingival bleeding index scores were significantly reduced after periods of rinsing with CHX solution (P less than 0.001) and AmF + SnF solution (P less than 0.05). Microbiological cultivations of saliva specimens revealed significant reductions in mutans streptococci immediately after commencing rinsing, while lactobacilli and yeast counts were not affected.

Antibacterial activity of dental gels containing combinations of amine fluoride, stannous fluoride, and chlorhexidine against cariogenic bacteria

The in vitro susceptibility of Streptococcus mutans, S. sobrinus and Lactobacillus casei to dental gels containing various combinations of amine fluoride (AmF 297), stannous fluoride (SnF2), and chlorhexidine (CHX) was studied. The combination of AmF-SnF2 with a total fluoride content of 1.2% was the most effective against mutans streptococci but not against L. casei. At notably lower total fluoride concentration (0.4%), AmF as such or combined with SnF2, was significantly less effective against mutans streptococci than CHX or CHX-AmF-SnF2 combinations. CHX-AmF combination was a slightly more potent inhibitor of streptococcal growth than CHX-NaF. With L. casei the differences between various gels were small but CHX alone seemed to be the most effective. Of the studied agents, CHX seemed to be the most potent individual chemotherapeutic compound whose activity against S. mutans could be enhanced by combining it with AmF. However, clinical experiments are required to test the in vivo antibacterial efficacy of CHX-AmF and AmF-SnF2 combinations which were most effective in our in vitro experiments.