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1 Effect of Rinsing with Toothpaste Slurries and Water Solutions with a High Fluoride Concentration (5000 ppm) on de novo Plaque Formation Anna Nordström 1 , Chrysostomos Mystikos 2 , Per Ramberg 2 , Dowen Birkhed 1 Departments of Cariology 1 and Periodontology 2 , Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Sweden ______________________________________________________________ Short title: Toothpaste with 5000 ppm F and Plaque Formation Address: Dowen Birkhed, Department of Cariology, Institute of Odontology, Box 450, SE-405 30 Göteborg, Sweden. E-mail: [email protected]

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Effect of Rinsing with Toothpaste Slurries and Water Solutions with a

High Fluoride Concentration (5000 ppm) on de novo Plaque

Formation

Anna Nordström1, Chrysostomos Mystikos2, Per Ramberg2, Dowen Birkhed1

Departments of Cariology1 and Periodontology2, Institute of Odontology, Sahlgrenska

Academy, University of Gothenburg, Sweden

______________________________________________________________

Short title: Toothpaste with 5000 ppm F and Plaque Formation

Address: Dowen Birkhed, Department of Cariology, Institute of Odontology, Box 450,

SE-405 30 Göteborg, Sweden. E-mail: [email protected]

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Nordström A, Mystikos C, Ramberg P, Birkhed D. Effect of Rinsing with Toothpaste Slurries

and Water Solutions with a High Fluoride Concentration (5000 ppm) on de novo Plaque

Formation. Eur J Oral Sci

The aim of this study was to evaluate the effect of rinsing with toothpaste slurries and water

solutions with a high fluoride concentration on de novo plaque formation. 16 subjects rinsed 3

times/day for 4 d with the following dentifrice slurries: 5000, 1500 and 500 ppm F, while 12

subjects rinsed with water solutions: 5000, 1500, 500, 0 ppm F and 1.5% SLS (sodium lauryl

sulphate). Plaque was scored (QHI index) after each 4-d period. Plaque samples for F analysis

were collected. Significantly (P < 0.5) less plaque was scored for the dentifrice slurry with

5000 ppm F (buccal and all surfaces) and for 1.5% SLS (buccal surfaces). The differences in

plaque scores between dentifrice with 5000 and 1500 ppm F were 19% for all surfaces and

33% for buccal surfaces. The difference between the water solutions with 1.5% SLS and 1500

ppm F for buccal surfaces was 23%; the corresponding difference for 5000 ppm F was 17%

(P < 0.05). The dentifrice slurry with 5000 ppm F accumulated 56% more F in plaque (P <

0.05). The combination of high levels of F and SLS in dentifrice reduces de novo plaque

formation and increases the accumulation of F in plaque after 4 d.

Key words: Dental plaque, Dentifrice slurry, Fluoride, Plaque formation

Dowen Birkhed, Department of Cariology, Institute of Odontology, Box 450, SE-405 30

Göteborg , Sweden. Telefax: +45 31 82 57 33. E-mail: [email protected]

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The plaque-inhibiting effect of several antimicrobial substances, such as triclosan, essential

oils and chlorhexidine, has been reported (1-3). Fluoride (F), especially in toothpaste, is

widely used as a highly effective anti-caries agent. The daily supply of a low concentration of

F in saliva and plaque favours the remineralisation of enamel surface lesions (4). Fluoride in

the oral cavity may interact with the bacterial metabolism and its acid production and further

slow down the caries process (5). Moreover, F reduces the acid tolerance of the bacteria and

thereby decreases the cariogenicity of dental plaque (6). BAYSAN et al. (7) found significantly

lower plaque scores after 3 and 6 months in a group using a dentifrice with 5000 ppm F,

compared with a dentifrice with 1100 ppm F. According to LYNCH et al. (8), the level of F in

a 1500 ppm toothpaste is insufficient to interfere with bacterial growth and metabolism.

However, the anti-plaque effect of dentifrice slurries with a higher F concentration has so far

not been thoroughly investigated. The aim of the present investigation was therefore to study

the effect of daily rinsing with dentifrice slurries and water solutions with a high

concentration of F (5000 ppm) on de novo plaque formation during a 4-d period of no

mechanical cleaning. The accumulation of F in plaque was also studied.

Material and Methods

Two test series, here called I and II, were carried out with a randomised, cross-over design.

Series I was single blind with 3 cells and Series II was double blind with 5 cells. Sixteen

healthy dental students, aged 21-43 (mean age 27 yr), were recruited to Series I. Twelve of

these 16 subjects also participated in Series II (mean age 24 yr). Each volunteer had to fulfil

the following inclusion criteria: (i) good general health, (ii) no sign of destructive periodontal

disease, (iii) a minimum of 24 teeth with no extensive restorations and no teeth with exposed

root surfaces of > 1 mm, (iv) no antibiotic treatment during 3 months prior to the start of the

trial, (v) no regular medication with anti-inflammatory compounds, (vi) no use of tobacco

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products and (vii) no use of antiseptics. All subjects received a verbal and written description

of the study design and signed informed consent forms. This design, studying 4-d de novo

plaque formation, has previously been approved by the ethical review board at the University

of Gothenburg.

All 16 subjects were considered to be “heavy plaque formers” and were selected from 30

subjects during a 4-wk screening period, preceding the start of the trial. The definition of

heavy plaque formers was based on the criteria specified by MAGNUSSON et al. (9), who

evaluated the rate of plaque formation after 16-20 h of no oral hygiene. During a 2-wk

preparatory period, each subject received a series of thorough dental prophylaxis, including

scaling and professional mechanical tooth cleaning, (PMTC) (10), in order to establish

healthy gingival conditions. The teeth were professionally cleaned with a hand-piece and a

rubber cup, using RDA 170 polish paste (CCS AB, Borlänge, Sweden) and flossed. In

addition, the subjects were given instruction in proper oral hygiene measures and were told to

use an F-free dentifrice, prior to and between each experimental period. The PMTC was

repeated during a 2-wk preparatory period when indicated.

Series I (toothpaste slurries)

On a given day (Day 0), dental plaque was disclosed with erythrosine (Diaplac®, LIC AB,

Enköping, Sweden) and all the participants received PMTC. They were asked to refrain from

tooth brushing and proximal cleaning but to rinse with 1 ml of the assigned toothpaste slurry,

3 times/day, for 2 min and for 4 d (in the morning after breakfast, after lunch and in the

evening, just before bedtime). 1 ml of the dentifrice slurry was corresponding to the amount

of 1 g toothpaste used for ordinary tooth brushing. The rinsing procedure was carried out with

active movements of the lips and cheeks in order to enforce penetration of the slurry into

proximal sites. The subjects were instructed not to rinse with water after expectorating the

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slurry and not to eat or drink for 2 h. The following three Duraphat (Colgate-Palmolive AB,

Danderyd, Sweden) dentifrice slurries were used in random order: (1) dentifrice, 5000 ppm F,

(2) dentifrice plus water (dilution 1:2), 1500 ppm F and (3) dentifrice plus water (dilution

1:9), 500 ppm F. Each subject was provided with the slurries in 12 disposable syringes of 1

ml and was instructed to mix them for 10 s before application in the mouth. Plaque sampling

and plaque scoring were performed at the end of each experimental 4-d period. The test

periods were separated by a 3-d wash-out period using F-free toothpaste.

Series II (water solutions)

Series II was carried out 6 months later and comprised 12 of the 16 subjects who participated

in Series I. The dentifrice slurries were changed to water solutions with F, in order to show

the effect of sodium lauryl sulphate (SLS) in the dentifrice on plaque formation. The

experiment was similar to Series I, except that no plaque sampling was carried out. The

following five water solutions were used in random order: 1) 5000 ppm F, 2) 1500 ppm F, 3)

500 ppm F, 4) 0 ppm F and 5) 1.5% SLS and 0 ppm F.

Plaque registration (Series I & II)

Plaque was registered at the end of the 4-d period in two quadrants, by one of the authors

(C.M.). After disclosing with erythrosine (Diaplac®, LIC AB, Enköping, Sweden), plaque

was scored at six sites (mesiobuccal, buccal, distobuccal, mesiolingual, lingual and

distolingual) on all the teeth, according to the criteria specified in the Turesky modification of

the Quigley & Hein Index (QHI) (11, 12). Plaque sampling in Series I was performed prior to

the disclosure procedure in order to avoid any possible interaction with and influence of

erythrosine.

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Plaque sampling (Series I)

Plaque was collected 2 h after the last rinsing procedure, from all tooth surfaces in the 1st and

3rd quadrants in 8 subjects and in the 2nd and 4th quadrants in the remaining 8 subjects.

Proximal plaque was collected from all proximal sites, except the lower anterior region, using

extra–wide, waxed fluoride-free dental floss. Plaque on smooth surfaces (buccal and lingual)

was collected with an amalgam carver. The plaque material was transferred to a pre-weighed

2-ml plastic tube (Eppendorf PRC, Sarstedt, Nümbrecht, Germany). This was done by

drawing the floss through a slit, which had been cut in the lid of the tube. Plaque adhering to

the floss was thereby left on the inside of the tube and weighed. The total amount of plaque,

collected from proximal and smooth surfaces, was weighed and expressed as mg wet weight

and determined to the nearest 0.1 mg. The samples were frozen at –20˚C pending further

analysis. The samples were processed and analysed with respect to F concentration according

to FURUICHI & BIRKHED (2). A volume of 200 µl of liquid, consisting of TISAB III (Thermo

Electron Corp., Waltham, USA) and distilled water (1:10), was added to the plaque samples.

The plaque suspension was homogenised by sonification for 20 s (Branson W185D,

Dansbury, Connecticut, USA) and kept in a refrigerator (+4˚C) over night, in order to disperse

the plaque. The tubes were vibrated in a Minishaker MS1 (IKA, Wilmington, USA) for 20 s,

100 µl of the solution was placed as a drop on a Petri dish and the F concentration was

measured by carefully lowering the electrode into the fluid. The surface tension of the drop

ensured that the liquid enclosed the entire membrane surface of the electrode. In order to

calibrate the ion-specific electrode (model 96-09, Orion Research), three standard solutions

(0.1, 1.0, and 10 ppm F) were analysed. The F concentration was expressed as both ppm F

and ng F/mg plaque wet weight.

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Statistical analysis

The mean QHI scores for all surfaces (Series I & II) and the mean F concentration in plaque

(Series I) were the outcome variables. Power analyses were based on a standard deviation of

0.8 QHI score units. There was a 80% power to detect a 20% difference in mean plaque

reduction including 12 subjects. Analysis of variance (two-way ANOVA), followed by

Student-Neumann-Keul’s (SNK) test, were applied to evaluate if there were significant

differences between the 4-day periods. P < 0.05 were considered statistically significant.

Results

Plaque index (Series I and II)

The mean QHI scores for buccal and all surfaces in Series I and II are presented in Fig. 1. In

Series I, the difference in mean QHI scores between the dentifrice slurry with 5000 ppm F

and the 1500, 500 ppm F slurries was statistically significant for buccal and all surfaces (P <

0.05). The differences in plaque scores between the dentifrice slurry with 5000 and 1500 ppm

F were 19% for all surfaces and 33% for buccal surfaces. In Series II, the difference in mean

QHI scores between the solution with 1.5% SLS, and the 5000, 1500, 500 0 ppm F solutions

was statistically significant for buccal surfaces (P < 0.05). The difference between the 1.5%

SLS solution and 1500 ppm F was 23% and the corresponding difference for 5000 ppm F was

17%.

Fluoride accumulation in plaque (Series I)

The amount of plaque and the accumulation of F in plaque for the three dentifrice slurries are

presented in Table 1. There was no significant difference regarding the amount of plaque (wet

weight). The difference in the accumulation of F in plaque (expressed as ppm F) between

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dentifrice slurries with 5000 ppm F and 1500 ppm F was 56%, which was statistically

significant (P < 0.05). The corresponding difference for 500 ppm F was 63%, which was also

statistically significant (P < 0.01).

Discussion

In the present 4-d experimental study, significantly less de novo plaque was scored for the

dentifrice slurry with 5000 ppm F and for the water solution with 1.5% SLS. This is in

agreement with BAYSAN et al. (7), who observed that the plaque index after 3 and 6 months

was significantly lower in a 5000 ppm F compared with an 1100 ppm F group. However, the

study was originally designed to compare the ability of two sodium fluoride dentifrices to

reverse primary root caries lesions and the reduction of plaque scores was not the primary

outcome. No other studies have investigated the anti-plaque effect of dentifrice slurries with a

high F concentration (5000 ppm F), hence a number of studies have described the anti-caries

effect of F.

Bacteria grow preferentially attached to surfaces embedded in an exopolysaccharide matrix

to form biofilms. In this mode of growth, bacteria often show reduced susceptibility to

antimicrobials and a higher concentration of such detergents is needed. The anti-caries actions

of F appear to be complex, involving both on bacteria and on mineral phases. Fluoride acts to

reduce the acid tolerance of the bacteria and thereby decreases the cariogenicity of dental

plaque and the effect is most persistent at low pH values (5). Fluoride in the oral cavity may

also interact with the bacterial metabolism and its acid production and further slow down the

caries process (6). Both F and SLS in dentifrices are usually regarded as weak plaque

inhibitors and LYNCH et al. (8) concluded that the level of F in 1500 ppm toothpaste is

insufficient to interfere with bacterial growth and metabolism. In addition, VAN LOVEREN et

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al. (13) observed that F dentifrice does not affect plaque composition or F tolerance or the

acidogenicity of mutans streptococci.

The present study also showed a reduction of plaque scores for water solution with 1.5%

SLS. The anionic detergent SLS is a common compound in dentifrices. It is included mainly

because of its foaming activity, but effects on dental plaque have also been reported. The

antimicrobial action of SLS is related to its adsorption and penetration through the porous cell

wall following by interaction with components of the cell membrane, lipids and proteins (14,

15). The penetration of SLS into the membrane causes an increase in cell permeability, which

may result in leakage of intracellular components and cell lysis (14). This result is in

agreement with data presented by WAALER et al. (16), who concluded that a mouthwash

containing 1.5% SLS inhibit plaque formation after 4 d. FERNANDA et al. (17) has reported

that SLS alone and in combination with NaF reduce the bacterial viability, lactate formation

and extracellular polysaccharide formation both in vitro and in vivo. It was also concluded

that SLS and NaF in combination had additive effects (17). The viability of bacteria in newly

formed plaque may therefore be of some interest. Dental plaque bacteria forms complex and

robust cell aggregates which cannot be counted accurately using epifluorescence microscopy

and this causes a problem for quantifying their viability. FILOCHE et al. (18) developed a

fluorescence assay to quantify the viable biomass of dental plaque biofilms. The conflicting

result from this study showed that F at 1000, 3000 and 5000 ppm promote plaque viability.

Further studies evaluating the viability of bacteria in newly formed plaque after using a

dentifrice with 5000 ppm F are therefore needed.

We noticed that the reduction of plaque scores in the present study was more extended for

buccal surfaces. An explanation could be that the dentifrice slurry and water solutions more

easily had access to and penetrated this surface by the active movements of the lips and

cheeks.

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The subjects in the present study were all dental students and had relatively low levels of

cariogenic bacteria, even though they were regarded as “heavy plaque formers”. Thirteen of

16 volunteers had none or less than 100,000 mutans streptococci/ml. Only 3 subjects had

more than 1,000,000 CFU/ml. The lactobacillus scores were extremely low; 15 subjects of 16

had less than 10,000 CFU/ml. According to SEKINO et al. (1), the number of salivary

bacteria may influence the amount of plaque formed during the early phase of no oral

hygiene. In the present study, the mean QHI plaque scores after 4 d (around 2.5-3; Fig.1) are

in agreement with findings in other studies using the 4-d de novo plaque formation model

(19).

An experimental period of 4 d may at first be regarded as short for detecting major

differences in de novo plaque formation for weak plaque inhibitors. However, according to

FURUICHI & BIRKHED (20) and RAMBERG et al. (19), no major difference was observed in

plaque formation after 4 or 14 d of no mechanical cleaning. The plaque-inhibiting effect

observed by BYASAN et al. (7) for a dentifrice with 5000 ppm F was actually detected after a

period of 3 and 6 months. It has been suggested that intra-oral fluoride reservoirs may take

weeks to “fill”, possible due to the time taken for establishment of steady-state F

concentration in plaque and saliva (21). On the other hand, CLAYDON & ADDY (22) concluded

that even a 24-h plaque re-growth study design, using conventional measurements of plaque

accumulation, could be useful as a rapid method of screening potential inhibitory agents and

formulations. From an ethical point of view, it is preferable to use a short experimental

period, since the subjects had to refrain from all oral hygiene. As previously mentioned, both

F and SLS in dentifrices are usually regarded as weak plaque inhibitors. However, in the

present study, the concentration of F in the dentifrice (5000 ppm F) was 3.5 times higher than

that in a standard dentifrice (1500 ppm F) and the rinsing procedure was extended from 2 to 3

times a day. According to WATSON et al (5), the penetration of F into natural plaque biofilms

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increased with duration of NaF exposure. Furthermore, the Duraphat dentifrice is

recommended to be used 3 times a day for patients with a high caries risk, according to the

manufacturer.

The difference in the accumulation of F in plaque (Series I) between dentifrice slurries

with 5000 and 1500 ppm F was 56%. The results of earlier studies of F accumulation diverge.

FURUICHI & BIRKHED (2) observed that the retention of F in plaque was less, when F was

delivered in a dentifrice rather than in a mouth rinse. According to PESSAN et al. (23), the

difference between dentifrices and solutions, in terms of their ability to increase plaque F

concentration, may be due to the presence of SLS. The use of F in dentifrice is likely to

increase the plaque F concentration significantly for up to 12 h (23). In contrast, HEIJNSBROEK

et al. (24) reported that F does not accumulate in plaque over time. The concentration of F in

a dentifrice may influence the retention of F in both plaque and saliva. In a recent study, we

found that the accumulation of F in plaque was 2 times higher for a dentifrice with 5000 than

for the dentifrice with 1450 ppm F, after 14 d (25).

In summary, significantly less de novo plaque was observed for the dentifrice slurry with

5000 ppm F (on buccal and all surfaces), for the water solution with 1.5% SLS (on buccal

surfaces) and the reduction ranged from 17 to 33%. We therefore conclude that the

combination of high levels of F (5000 ppm) and 1.5% SLS in a dentifrice reduces de novo

plaque formation and increases the accumulation of F in plaque, after 4 d with daily rinsing, 3

times a day. We believe that this reduction of de novo plaque formation have a clinical

importance.

Acknowledgements

We gratefully acknowledge the technical assistance of Ann-Britt Lundberg and the statistical

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assistance of Tommy Johnsson. This study was supported by the Institute of Odontology,

University of Gothenburg.

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References

1. SEKINO S, RAMBERG P, UZEL NG, SOCRANSKY S, LINDE J. Effect of various

chlorhexidine regimes on salivary bacteria and de novo plaque formation. J of Clin

Periodont 2003; 30: 919-925.

2. FURUICHI Y, BIRKHED D. Retention of fluoride/triclosan in plaque following different

modes of administration. J of Clin Periodont 1999; 26: 14-8.

3. SATOSHI S, RAMBERG P. The effect of a mouth rinse containing phenol compounds on

plaque formation and developing gingivitis. J of Clin Periodont 2005; 32: 1083-1088.

4. MARINHO VC, HIGGINS JP, SHEIHAM A, LOGANS S. Fluoride toothpastes for

preventing dental caries in children and adolescents. Coch Data Syst Rev 2003;

CD002278.

5. MARQUIS RE. Antimicrobial actions of fluoride for oral bacteria. Can J of Microb

1995; 41: 955-964.

6. WATSON PS, PoNTEFRACT HA, DEVINE DA, SHORE PC, NATTRESS BR, KIRKHAM J,

ROBINSON C. Penetration of fluoride into natural plaque biofilm. J of Denl Res 2005;

84: 451-455.

7. BAYSAN A, LYNCH E, ELLWOOD R, DAVIES R, PETERSSON L, BORSBOOM P. Reversal

of primary root caries using dentifrices containing 5000 and 1100 ppm fluoride. Car

Res 2001; 35: l41-146.

8. LYNCH RJ, NAVADA R, WALIA R. Low levels of fluoride in plaque and saliva and their

effects on demineralisation and remineralisation of enamel; role of fluoride

toothpastes. Int Dent J 2004; 54: 304-309.

9. MAGNUSSON I, ERICSON T, PRUITT K. Effect of salivary agglutinins on bacterial

colonization of tooth surfaces. Car Res 1976; 10: 113-122.

10. AXELSSON P, LINDHE J. The effect of a preventive programme on dental plaque,

gingivitis and caries in schoolchildren. Results after one and two years. J of Clin

Periodont 1974; 1: 126-138.

11. TURESKY S, GILMORE ND, GLICKMAN I. Reduced plaque formation by the

chloromethyl analogue of vitamin C. J of Periodont 1970; 41: 41-43.

12. QUIGLEY GA, HEIN JW. Comparative cleansing efficiency of manual and power

brushing. J of Am Dent Ass 1962; 65: 26-29.

Page 14: Effect of Rinsing with Toothpaste Slurries and Water ... · Effect of Rinsing with Toothpaste Slurries and Water Solutions with a ... calibrate the ion-specific electrode ... Analysis

14

13. VAN LOVEREN C, BOIIS JF, KIPPUW N, TEN CATE JM. Plaque composition, fluoride

tolerance and acid production of mutans streptococci before and after the suspension

of the use of fluoride toothpastes. Car Res 1995; 29: 442-448.

14. SALTON MR. Lytic agents, cell permeability, and monolayer penetrability. J Gen

Pysiol 1968; 52: 227-252.

15. BARTNIK. Interaction of anionic surfactants with proteins, enzymes and membranes.

In: Gloxhuber K, editor. Anionic surfactants: biochemistry, toxicology, dermatology.

New York: Dekker; 1992.

16. WAALER SM, RÖLLA G, SKJÖRLAND KK, OGAARD B. Effect of oral rinsing with

triclosan and lauryl sulphate on dental plaque formation: a pilot study. Scand J of Dent

Res 1993; 4: 192-195.

17. FERNANDA C, PETERSEN FC, ASSEV S, SCHEIE AA. Combined effects of NaF and SLS

on acid- and polysaccharide-formation of biofilm and planktonic cells. Arch of Oral

Biology 2006; 51: 665-671.

18. FILOCHE SK, COLEMAN MJ, ANGKER L, SISSONS CH. A fluorescence assay to

determine the viable biomass of microcosm dental plaque biofilms. J of Microb Meth

2007; 69: 489-496.

19. RAMBERG P, FURUICHI Y, VOLPE AR, GAFFAR A, LINDE J. The effect of antimicrobal

mounthrinses on de novo plaque formation at sites with healthy and inflamed

gingivae. J of Clin Periodont 1996; 23: 7-11.

20. FURUICHI Y, RAMBERG P, LINDE J, NABI N, GAFFAR A. Some effects of mounthrinses

containing salifluor on de novo plaque formation and developing gingivitis. J of Clin

Periodont 1996; 23: 795-802.

21. DUCKWORTH RM, MORGAN SN. Oral fluoride retention after use of fluoride

dentifrices. Car Res 1991; 25: 123-129.

22. CLAYDON N, ADDY M. The use of plaque area and plaque index to measure the effect

of fluoride and chlorhexidine toothpastes on 24-h plaque re-growth. J of Clin Periodot

1995; 22 540-542.

23. PESSAN JP, SILVA SMB, LAURIS FC, SAMPAIO FC, WHITFORD GM, BUZALAF MAR.

Fluoride uptake by plaque from water and from dentifrice. J of Dent Res 2008; 87:

461-465.

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24. HEIJNSBROEK M, GERARDU VAM, BUIJS MJ, VAN Loveren C, TEN CATE JM,

TIMMERMAN MF, VAN DER WEIJDEN GA. Increased salivary fluoride concentrations

after post-brush fluoride rinsing not reflected in dental plaque. Car Res 2006; 40: 444-

448.

25. NORDSTRÖM A, BIRKHED D. Fluoride retention in interdental plaque and saliva using

two NaF dentifrices 5000 and 1450 ppm F with and without water rinsing. Car Res

2009; 43: 64-69.

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Legend to figure

Fig. 1. The mean plaque index (QHI) scores ± SD for buccal and all surfaces, representing

each experimental 4-d period in Series I (Toothpaste slurries; n=16) and in Series II (Water

solutions; n=12).

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Table 1. The amount of collected plaque (expressed as mg wet weight) and the accumulation

of F in plaque, expressed as ppm F in the extracted plaque suspension or as ng F per mg

plaque wet weight (mean ± SD of 16 subjects), for the three dentifrice slurries in Series I. The

samples were collected after a 4-d experimental period. The difference between 5000 and

1500 ppm F was statistically significant (P < 0.05) and the corresponding difference for 500

ppm F was also statistically significant (P < 0.01).

F concentration mg wet weight ppm F ng F/mg plaque

5000 ppm F 9.56 ± 3.3 3.86 ± 2.6 0.44 ± 0.34

1500 ppm F 7.31 ± 3.7 1.68 ± 1.6 0.34 ± 0.57

500 ppm F 9.36 ± 4.3 1.41 ± 1.2 0.16 ± 0.11