Coffee-stained tooth enamel color restoration and surface abrasion with whitening and regular toothpaste.

PURPOSE: To evaluate the effectiveness of whitening toothpaste in restoring tooth color after coffee staining and its potential impact on enamel surfaces compared with regular toothpaste. METHODS: Bovine tooth enamel specimens were prepared and stained with coffee solutions before undergoing brushing simulation with different toothpaste slurries (whitening, regular, reference). For precise evaluation, spectrophotometric measurements were taken at intervals to assess color changes using the CIELAB (Commission Internationale de l'Éclairage Lab*) color space. Additionally, profilometric measurements were taken to determine the impact of toothpaste type on the roughness and abraded depth of the enamel surface. To understand the effects of toothpaste and brushing on color change, surface roughness, and abraded depth, while also considering correlations between these factors, the findings were analyzed using mixed-effects models. RESULTS: The whitening toothpaste group demonstrated the highest recovery rate (71%) after 10,000 brushstrokes, followed by the regular toothpaste group (48%) and the reference slurry group (43%). The mixed-effects model analysis revealed that the reference group had a smaller change in lightness (ΔL) than those in the regular toothpaste group. The whitening toothpaste group showed a greater change in lightness on average than those in the regular toothpaste group, with an increase in lightness as the number of brushstrokes increased. According to the roughness and abraded depth data, the whitening toothpaste group was least affected by brushing, while the reference and regular toothpaste groups showed higher levels of roughness and abraded depth at all intervals. CLINICAL SIGNIFICANCE: Gaining a thorough understanding of the effectiveness of whitening toothpaste and its impact on the enamel surface plays a crucial role in refining toothpaste formulations and advancing tooth whitening techniques in dental care.

Protection Against Discolouration by Two Over-the Counter Desensitising Products.

PURPOSE: To determine in vitro the protection potential against discolouration of two OTC (over-the-counter) desensitising products on enamel and dentin in comparison to a standard toothpaste and water by means of a spectrophotometer. MATERIALS AND METHODS: A total of 96 samples of bovine enamel-dentin complex and 48 of bovine dentin were alternatively immersed in red wine, tea, coffee or water after having been treated by a sodium monofluorophosphate- and calcium phosphate-based product (Curodont Protect), an amine fluoride-based toothpaste (Elmex Red), a stannous chloride-based toothpaste (Elmex Protection Erosion) or distilled water (negative control). Initial (T0) and final colour (T1, after 4 weeks of immersion in staining solutions) of each specimen were assessed by a spectrophotometer. Statistical analysis was done by means of repeated measures ANOVA followed by Fisher's LSD post-hoc test. Differences between T0 and T1 were considered stastistically significant at p ≤ 0.05. RESULTS: When enamel samples were measured over a black background, ΔE00 values (T0-T1) varied from 2.2 (SD 0.7) for amine fluoride-based product/water to 53.9 (SD 7.6) for amine fluoride-based-product/red wine. When dentin samples were measured over a black background, ΔE00 values (T0-T1) varied from 5.4 (SD 0.9) stannous chloride based product/water to 61.6 (SD 3.7) amine fluoride-based product/red wine. CONCLUSION: Specifically, the application of the sodium monofluorophosphate was able to statistically significantly (p ≤ 0.05) reduce discolouration induced by the staining solutions tested only on the enamel-dentin complex, while distilled water and the stannous fluoride-based product were able to statistically significantly (p ≤ 0.05) reduce discolouration induced by the staining solutions tested in pure dentin samples.

White diet: is it necessary during tooth whitening?

Patients are sometimes blamed for a reduced effect of bleaching when they do not adhere to a dentist's prescribed white diet. This study aimed to determine whether a white diet is necessary by evaluating the effects of coffee, tea, wine, and dark fruits on the potential tooth whitening during the bleaching process. Each of the effects of discoloration was categorized as "yes" or "no" based on a patient questionnaire. Data from five published studies were included in the analyses. Outcomes were based on the color change between baseline and the end of bleaching. The relationships between color changes were measured subjectively and objectively. A nonwhite diet was not significantly associated with less tooth whitening, and there was only a weak positive association between tooth whitening and diet for subjects who drank large amounts of coffee/tea.

Teeth whitening versus the influence of extrinsic factors on teeth stains.

The improvement of teeth colour is the effect of using whitening toothpastes, professional removal of dental deposits, pulpless teeth and vital teeth whitening. The aim of the study was evaluation of various methods of teeth whitening in relation to sex and age of the investigated as well as the extrinsic factors causing teeth stains such as cigarette smoking, consumption of coffee and tea. Questionnaire survey was conducted in the group of 204 patients, reporting for a dental treatment at the Chair and Department of Conservative Dentistry with Endodontics of the Medical University of Lublin as well as private dental practice in Lublin. Questionnaire survey was elaborated for the needs of the planned investigation and included questions concerning, among others, socio-demographic data of the investigated, methods of teeth whitening, cigarette smoking, consumption of coffee and tea. Statistic analysis was performed with the use of descriptive statistics, Chi2 test, Mann-Whitney test. The values of p < 0.05 were considered statistically essential. Women used whitening toothpastes more frequently in comparison with men (χ2 = 7.96, p < 0.01). People who declared drinking at least one coffee cup used whitening toothpastes more frequently in comparison with the people drinking coffee occasionally and those who didn't drink it (χ2 = 9.99, p < χ0.05).

Dental plaque, gingival inflammation and tooth -discolouration with different commercial -formulations of 0.2% chlorhexidine rinse: a double-blind randomised controlled clinical trial.

PURPOSE: To investigate the efficacy of various formulations of chlorhexidine 0.2% (CHX) in terms of plaque and gingival bleeding control compared to each other and to saline rinse (CTRL) over a 35-day rinsing period. MATERIALS AND METHODS: Seventy subjects were randomly allocated to one of 4 groups rinsing twice daily for 35 days. The different groups used CHX 0.2% rinse with alcohol (CHX1) and without alcohol (CHX2), with an antidiscolouration system (CHX3) or saline rinse (CTRL). Clinical examinations to evaluate full-mouth plaque scores (FMPS) and periodontal parameters were performed at baseline, 7, 21 and 35 days. Tooth discolouration (TD) was measured at each time point using digital photographs and spectrophotometric analysis. RESULTS: At 35 days, CTRL showed the highest levels of plaque. The mean changes in FMPS from baseline were 69.8% ± 6.8 for CHX1, 57.5% ± 9.8 for CHX2, 43.7% ± 9.8 for CHX3 and 25.8% ± 7.7 for CTRL. Statistically significant differences were demonstrated between CHX1 and CHX3 (p = 0.02), CHX2 vs CHX3 (p ≤ 0.05) and CHX1/CHX2 vs CHX3 (p < 0.05). In contrast, CHX3 appeared more effective in reducing inflammatory indexes. TD increased over time in 60% to 70% of participants, although lighter staining was found in the CHX3 group. Greater FMPS reduction was observed in participants with staining vs without staining (26.0% ± 12.3, p = 0.04). CONCLUSION: Conventional CHX appeared more effective in terms of plaque reduction. Interestingly, the newest formulation showed a higher control of gingival inflammation. Staining was associated with lower plaque levels.

Comparison of effectiveness of abrasive and enzymatic action of whitening toothpastes in removal of extrinsic stains - a clinical trial.

OBJECTIVE: To compare the effectiveness of abrasive component (perlite/calcium carbonate) and enzymatic component (papain and bromelain) of whitening toothpaste in removal of extrinsic stains. METHODS: This study is a randomized, triple blind and parallel group study in which 90 subjects aged 18-40 years were included. At baseline, stains scores were assessed by Macpherson's modification of Lobene Stain Index and subjects were randomly assigned to two groups with 45 subjects in each. Group 1 used whitening toothpaste with enzymatic action and group 2 with abrasive action. After 1 month, stain scores were assessed for the effectiveness of the two toothpastes and 2 months later to check the stain prevention efficacy. Wilcoxson's test was used to compare between baseline 1 and 2 months stain scores, and Mann-Witney U-test was applied for intragroup comparison. RESULTS: The mean baseline total stain score for the subjects allocated to the enzymatic toothpaste was 37.24 ± 2.11 which reduced to 30.77 ± 2.48 in 1 month, and for the abrasive paste, total stain reduced from 35.08 ± 2.96 to 32.89 ± 1.95. The reductions in total stain scores with both the pastes were significant compared with baseline stain scores (at 1 month Group 1, P = 0.0233 and Group 2, P = 0.0324; at 2 months, Group 1 P = 0.0356). Both the toothpastes proved to be equally good in removal of extrinsic stains; however, the enzymatic paste showed better results as compared to abrasive toothpaste. CONCLUSION: Whitening toothpaste with abrasive action and enzymatic action are equally effective in removal of extrinsic stains; however, whitening toothpaste with abrasive action needs to be used with caution.

Prevention of tea-induced extrinsic tooth stain.

OBJECTIVES: The objectives of this study were to determine whether the addition of milk to tea reduces the ability of tea to stain extracted human teeth and, if so, to ascertain the component of milk that is responsible for milk's stain reducing properties. METHODS: Extracted human teeth were immersed in a tea solution, with the addition of 2% milk, 5.26% lactose, 2.7% casein or 10% fat-free milk for 24 h at 37°C. A dental spectrophotometer (VITA Easyshade Compact) was used to evaluate the colour of the teeth both before and after immersion in the tea solutions. Commission internationale de l'éclairage (CIE) L*a*b* colour space values were recorded, and the change in colour (ΔE*) was calculated. A two-tailed t-test or one-way analysis of variance (anova) was used to determine whether there were statistical differences between groups. RESULTS: Milk significantly reduces the ability of tea to stain teeth (P = 0.0225), specifically in the L* and a* dimensions (P = 0.0182 and P = 0.0124, respectively) of the colour sphere. Casein, which makes up 80% of the protein content in bovine milk, is the component of milk that is responsible for significantly reducing tea's ability to stain teeth (P < 0.0001). CONCLUSIONS: The addition of milk to tea significantly reduces the tea's ability to stain teeth. Casein was determined to be the component of milk that is responsible for preventing tea-induced staining of teeth to a similar order of magnitude that can be obtained by vital bleaching treatments.

Masking of white spot lesions by resin infiltration in vitro.

OBJECTIVES: The aim of this in vitro study was to evaluate the ability of one commercial and five experimental infiltrating resins (infiltrants) to camouflage enamel white spot lesions immediately after resin infiltration and after a staining period. METHODS: In each of 120 bovine enamel samples, two artificial caries lesions were created (windows A and C; pH=4.95, 50 days), whereas two windows were protected serving as sound controls (B and D). After etching windows C and D (37% phosphoric acid), specimens were randomly allocated to 6 groups. Either one of 5 experimental infiltrants or a commercial infiltrant (Icon, DMG) (refractive indices 1.50-1.55) was applied and light cured. After half of each specimen was polished, samples were remineralized (pH=7.0) and stained with tea and red wine for 50 days. Photographic images after various treatment steps were obtained. Color differences (ΔE) of untreated (A) and treated lesions (C) as well as infiltrated sound enamel (D) were compared with untreated enamel (B). RESULTS: All infiltrants showed significantly better color match with sound enamel (median ΔE [25th/75th percentile]: 2.2 [1.5/3.1]) than untreated controls (9.3 [8.0/10.9]) (p<0.001, Wilcoxon, post hoc Bonferroni). Moderate correlation between refractive index and ΔE of infiltrated lesions was demonstrated (R(2)=0.43, p>0.05). Staining was significantly reduced for polished infiltrated lesions compared to untreated or infiltrated unpolished lesions (p<0.001). CONCLUSIONS: Resin infiltration is suitable to mask artificial white spot lesions. Polished infiltrated lesions are resistant to staining in vitro. CLINICAL SIGNIFICANCE: Resin infiltration is a micro-invasive approach to camouflage post-orthodontic white spot lesions.

Effect of nano-carbonate apatite to prevent re-stain after dental bleaching in vitro.

OBJECTIVES: This study examined the effect of nano-carbonate apatite (n-CAP) to prevent re-staining and the change of enamel surface after dental bleaching in vitro. METHODS: Twenty-four bovine specimens were bleached for 2 weeks with 10% carbamide peroxide (CP). After bleaching, the specimens were divided into the following four groups: distilled and deionized water (DDW, negative control), 10% n-CAP, NaF (positive control) and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP, positive control). Each group was subjected to pH cycling for 7 days. The specimens were treated for 4 min 3 times per day and re-staining was induced naturally by artificial saliva in the remineralization process. After pH cycling, the changes in colour were evaluated with spectrophotometry and scanning electron microscopy (SEM). The difference in colour between before and after pH cycling was evaluated using an ANOVA and Tukey test. RESULTS: After pH cycling, the colour difference of n-CAP group was significantly lower than that of the DDW and CPP-ACP groups (p<0.05). SEM showed that n-CAP particles were deposited regularly on the damaged surface compared to the other groups. CONCLUSION: 10% n-CAP could significantly maintain the initial colour and protect the damaged enamel structure after bleaching.

Biofilm reduction and staining potential of a 0.05% chlorhexidine rinse containing essential oils.

OBJECTIVES: To assess the biofilm reduction and discolouration potential of a new 0.05% chlorhexidine (CHX) digluconate solution, containing additional essential oil and alcohol components, compared with that of standard control CHX solutions (0.05% and 0.2% CHX). METHODS: The potential to reduce total viable counts of growing mixed microbial populations was examined using the Zurich biofilm model. Biofilms were created on sterile pellicle-coated hydroxyapatite discs and exposed to test substances at different time points. After 64.5 h, mean colony-forming units and SDs were determined. Colour change measurements using light reflection analysis were carried out on saliva preconditioned bovine dentin and enamel samples, as well as on composite and glass ceramic restorative materials, after successive immersions in a standardized tea brew and the CHX solutions. RESULTS: The test solution was able to reduce biofilm formation by 3 log steps compared with a negative (water) control. This was significantly less effective than the standard control CHX solutions, which reduced viable counts by 6 log steps. Both the test and control solutions exhibited staining on all surfaces. Staining was most pronounced on dentin, followed by enamel and to a significantly lesser degree on the restorative materials. Furthermore, the staining caused by the test solution on these restorative materials was generally lower than that caused by the control solutions. CONCLUSIONS: The test solution exhibited an antimicrobial activity. The composition, however, seems to hamper its effectiveness. Accordingly, it produced statistically significant, although by trend less, staining on restorative materials.

Effect on dental stain occurrence by chewing gum containing sodium tripolyphosphate--a double-blind six-week trial.

OBJECTIVE: A six-week controlled double-blind clinical study was conducted to assess and to measure the efficacy of a sugar-free chewing gum containing sodium tripolyphosphate (1%) on dental stain occurrence versus a placebo sugar-free chewing gum. METHODS: One-hundred and eleven subjects who had a Lobene Modified Index for stain extent score between 0.33 and 1.5 in their frontal teeth joined this study. Each subject entered in the test or the control group using a random table which allowed for an equal distribution of smokers and habitual tea users. Participants agreed to chew two gums (two grams each) three times per day, after meals, for ten minutes over six weeks. All received the same dentifrice containing only fluoride as the active agent. After six weeks, participants were scored for dental stain with the Lobene Modified Index. Data were scored by the same blinded operator for all measurements. Comparisons between the groups with respect to baseline scores were performed using an unpaired t-test, and inside the groups with a paired t-test (alpha = 0.05). RESULTS: One-hundred and eight subjects completed the trial; three left, but none reported problems linked to sodium tripolyphosphate. The mean difference for stain extent index after the six-week trial was 0.04 (+/- 0.08) in the control group, and -0.05 (+/- 0.08) in the test group (p < 0.001). A statistically significant reduction was also reported for intensity and composite indexes. The initial mean for stain extent index in the test group was 0.8 (+/- 0.34), and at six weeks was 0.74 (+/- 0.33; p < 0.001). The initial mean for extent index in the control group was 0.78 (+/- 0.3), and at six weeks was 0.81 (+/- 0.32; p < 0.005). CONCLUSION: This trial showed a reduction in dental stain by a chewing gum containing sodium tripolyphosphate after six weeks.

Tooth discoloration of immature permanent incisor associated with triple antibiotic therapy: a case report.

INTRODUCTION: A triple antibiotic mixture of ciprofloxacin, metronidazole, and minocycline was used as an intracanal medicament in an attempt to disinfect the root canal system for revascularization of a tooth with a necrotic pulp. However, discoloration developed after applying the triple antibiotic mixture. METHODS: Six weeks after a triple antibiotic paste had been applied to the root canal of tooth #8 of a 7-year-old girl, the tooth showed a dark discoloration. An in vitro experiment with human extracted teeth was performed to determine which of the 3 antibiotics caused the tooth discoloration. Another experiment was then carried out to examine whether a currently used dentin bonding agent would prevent or reduce such discoloration. The degree of discoloration was assessed by using a colorimeter. RESULTS: Among the components of the triple antibiotic paste, only minocycline caused the tooth discoloration. Moreover, the dentin bonding agent reduced the intensity of the discoloration but did not prevent it. CONCLUSIONS: The possible esthetic problems with the tooth color should be considered when using minocycline as a canal medication.

Effect of toothpaste containing d-limonene on natural extrinsic smoking stain: a 4-week clinical trial.

PURPOSE: To determine whether natural smoking stain could be removed/inhibited effectively by a toothpaste containing 5% d-limonene. For comparison and contrast, the effects of d-limonene on tea stain were also assessed. METHODS: The design was a randomized controlled double-blind trial with parallel groups. Toothpastes were: A: positive control with perlite whitening formulation; B: A+5% d-limonene; C: D + 5% d-limonene; D: negative control. The extrinsic stains were measured using Lobene Stain Index. Following baseline examination, all subjects were randomly assigned to one of the four toothpaste groups and instructed to brush with the assigned products twice daily. Subjects returned to the clinic after 4-week brushing for stain removal assessment, then all extrinsic stains, plaque and supragingival calculus were removed and use of assigned products was continued for another 4 weeks, and the stain scores were repeated for inhibition assessment. RESULTS: A total of 408 subjects, 201 with smoking stains and 207 with tea stains, participated in the trial. 5% d-limonene combined with Perlite whitening formulation significantly reduced stain scores both for smoking stain removal and inhibition (P < 0.05). Furthermore, 5% d-limonene alone (in negative formulation) exhibited an additional advantage for smoking stain inhibition (P < 0.05), but the advantage was not found for long-standing smoking stain removal (P > 0.05). The additional advantage of 5% d-limonene was shown neither for removal nor for inhibition in the tea stain study (P > 0.05). All test products were well tolerated over the study period.

Combined effects of staining substances on resin composites before and after surface sealant application.

The objective was to measure the combined effect of mucin, chlorhexidine and tea solution on the staining of four dental resin composites, and to determine the effect of surface sealant on staining. One side of cured resin composite specimens of 10 mm in diameter and 2 mm in thickness were polished with 600-grit silicon carbide paper. One group of specimens (n = 5) was treated with a surface sealant [BisCover, Bisco, USA; SS (surface sealant) group], and the other group was not (NO group; control). Specimens were sequentially immersed in the following substances: Mucin in phosphate buffered saline (PBS); chlorhexidine; tea solution; and ultrasonic cleaning and then immersion in PBS. Color was measured on a reflection spectrophotometer. Changes in color (DeltaE (*) (ab)) and color parameters, such as hue, chroma and value, after immersion in tea solution and subsequent cleaning were analyzed by repeated measures, analysis of variance at the 0.05 level of significance. The range of DeltaE (*) (ab) values after immersion in tea solution was 11.4-21.1 for NO group and 10.5-19.6 for SS group, and that after cleaning was 2.4-10.0 for NO group and 2.7-8.3 for SS group. After staining, CIE L (*) value (lightness) decreased, and CIE a (*) and b (*) values increased. Color changes of resin composites were not acceptable after sequential immersion treatment (DeltaE (*) ( ab ) > 3.3). The changes in color and color parameters of sealant applied group were not significantly different from those of control group except for a few combinations of color parameters and resin composites.

Ion uptake into demineralized dentine from glass ionomer cement following pretreatment with silver fluoride and potassium iodide.

BACKGROUND: Diamine silver fluoride (Ag(NH3)2F), referred to as AgF, has been shown to provide a pronounced antimicrobial action against caries. The clinical application of this material has been limited by the staining associated with both teeth and tooth coloured restorative materials. The application of potassium iodide (KI) after AgF eliminates stain formation. The purpose of this study was to determine if a prior application of silver fluoride and potassium iodine to demineralized dentine affected the uptake of strontium and fluoride from a glass ionomer cement restoration. METHOD: Three cavities were prepared in each of five recently extracted human third molars. The cavities were demineralized and treated as follows. In each tooth, one cavity was left as a control, one cavity was restored with glass ionomer cement and one cavity was treated with 1.8M AgF and a saturated KI solution and then restored with glass ionomer cement. The penetration of the various elements into demineralized dentine was measured by their relative percentage weights using electron probe microanalysis (EPMA). RESULTS: Fluoride uptake was significantly higher in the AgF and KI treated samples compared to the other two samples and significantly higher in the glass ionomer restored sample compared to the control. The application of AgF and KI did not significantly interfere with the transfer of strontium from glass ionomer cement into dentine. Silver and iodine deposits were present in the demineralized dentine treated with AgF and KI. CONCLUSIONS: The application of AgF and KI onto dentine prior to the placement of glass ionomer cement did not significantly affect the strontium uptake into the subjacent demineralized dentine and the fluoride levels in this zone were significantly increased.

In vitro studies on the effect of sodium tripolyphosphate on the interactions of stain and salivary protein with hydroxyapatite.

OBJECTIVES: To study properties of sodium tripolyphosphate (STP) relevant to inhibition or removal of dental stain in vitro. METHODS: The effects of STP and other phosphates on adsorption of a dietary chromogen (black tea polyphenol) and salivary protein to hydroxyapatite (HA) powder were studied by analysing loss of protein or tea stain from solutions mixed with HA or HA pre-treated with the test agents. The effects on desorption of protein and stain from HA were studied by analysis of water or solutions of test agents mixed with HA or HA pre-treated with saliva or tea solution. RESULTS: At concentrations and pH representative of those likely to occur in the mouth, STP inhibited adsorption of salivary protein and black tea polyphenol to, and desorbed these substances from, HA surfaces. Adsorption and desorption of protein and stain were not influenced by pH of the STP solutions but adsorption varied with concentration. STP showed equivalent effectiveness with respect to salivary protein adsorption and desorption as a longer-chain condensed phosphate. The inhibitory activity of HA-bound STP on adsorption of salivary protein and stain resisted extensive washing. CONCLUSIONS: STP is likely to be an effective agent for inhibiting and removing dental stain, whether bound directly to mineralised surfaces or indirectly via salivary pellicle.

Development of methods to enhance extrinsic tooth discoloration for comparison of toothpastes. 1. Studies in vitro.

BACKGROUND: The interaction of chlorhexidine with dietary chromogens to cause extrinsic dental staining has been exploited in vitro and in vivo to study tooth discoloration and its control. These studies in vitro investigated factors that might enhance stain formation, and evaluated formulations to inhibit the stain with the primary aim of devising a protocol for use in vivo. METHOD: The standard method cycled acrylic specimens through saliva, 0.2% chlorhexidine and tea on the hour 8 times per day and stain was measured using a spectrophotometer. Test interventions were 3 "whitening" toothpastes (A, P, R), a fluoride toothpaste (C) and water. In studies 1 and 3 interventions were at 09:00 and 16:00, and in studies 2 and 4 at 09:00 and 13:00. Between cycles, specimens remained dry in studies 1 and 2 and were maintained in water day and night in studies 3 and 4. Studies 5-7 determined the influence of tea temperature, exposure time and concentration, and chlorhexidine temperature and exposure time on stain development. Studies 8-10 modified the standard procedure using tea at triple strength and 50 degrees C, and assessed stain inhibition by toothpastes and water using optical density, colorimetric and visual assessment recordings. RESULTS: In studies 1-4, there were highly significant differences between interventions. Overall, the experimental whitening paste (P) produced the most stain inhibition, and water or the proprietary whitening paste (R), produced the least stain inhibition. More stain inhibition was seen with interventions at 09:00 and 16:00. Both tea concentration and temperature significantly influenced staining. Chlorhexidine temperature did not influence staining. Exposure time to tea and chlorhexidine had a small effect on staining. In studies 8 and 9, interventions at 09:00 and 16:00 were more effective; the most stain inhibition was with paste P and the least with water, paste R being intermediate. In study 10, P was the most effective and R the least effective interventions. CONCLUSIONS: These studies in vitro suggest that the chlorhexidine tea stain model can be manipulated to enhance stain and thereby should improve discrimination between stain inhibition formulations. The timing of interventions in the model appears to be important. These studies in vitro were used to plan a clinical protocol.

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

BACKGROUND: Extrinsic staining of teeth is considered to be unsightly and a number of 'whitening' toothpastes have been formulated to inhibit or remove such tooth discoloration. The aim of this study was to compare the stain prevention of two toothpastes. METHOD: The study was a single-blind, randomised, placebo-controlled, crossover design, balanced for residual effects involving 24 healthy dentate volunteers. The treatments were as follows: (1) a whitening toothpaste product, (2) an experimental toothpaste formulation and (3) water. For each 4-day rinse period, subjects were rendered stain free on the teeth and tongue. Approximately on the hour from 09:00 to 16:00 hours, subjects rinsed with chlorhexidine mouth rinse for 1 min followed by warm black tea for 1 min. The treatment interventions were at 09:00 and 16:00 hours and before the chlorhexidine rinse. The toothpastes were rinsed as 3 g/10 ml water slurries and water as a 10 ml rinse each for 2 min. On day 5, subjects were scored for tooth and tongue stain intensity and area, and the product of these was calculated. The washout period was at least 9 days. RESULTS: Treatment differences for the teeth were highly significant but not for the tongue. Paired contrasts for tooth stain intensity, area and product were mostly all significantly in favour of reduced staining by the experimental formulation compared with water and the whitening product. There were no significant differences between water and the whitening product. CONCLUSIONS: Using a forced dietary staining method, the data support a tooth stain-inhibitory/-removal action for the experimental formulation, but not the whitening product.

A chewing gum containing 7.5% sodium hexametaphosphate inhibits stain deposition compared with a placebo chewing gum.

The 2-period, randomized, double-blind, placebo-controlled, crossover study compared the stain-prevention and stain-removal benefit of a chewing gum containing 7.5% sodium hexametaphosphate (measured by digital image analysis) with a placebo chewing gum. The results of this study support that sodium hexametaphosphate delivered from a chewing gum prevents dental stain formation and facilitates stain removal, which leads to a perceptible whitening benefit. The long-term clinical benefits of sodium hexametaphosphate delivered from chewing gum have not been reported in the literature.

The prevention of induced stain using two levels of sodium hexametaphosphate in chewing gum.

OBJECTIVE: This study was a randomized, controlled, examiner-blind, four-period crossover design that examined the prevention of induced stain deposition through the use of chewing gums containing either 2.0% or 3.0% sodium hexametaphosphate (Na Hex). METHODOLOGY: The test treatments were an experimental chewing gum containing 2.0% Na Hex, a second experimental chewing gum containing 3.0% Na Hex, a placebo chewing gum (0.0% Na Hex) and no chewing gum. The study was carried out over a four-week period, with each treatment period lasting two days. Treatment periods were separated by a washout period of three to five days. Twelve subjects who met the inclusion and exclusion criteria were given a thorough dental prophylaxis limited to the anterior twelve teeth, and then underwent a baseline digital imaging assessment (DIA) procedure. Each treatment period involved two days of stain induction, which consisted of rinsing for 60 seconds with 10 ml of 0.12% chlorhexidine, followed by chewing with two pellets of the assigned chewing gum for five minutes or by no gum chewing, followed by rinsing with 10 ml of cold tea solution for 60 seconds. This regimen was repeated eight times throughout the day, approximately once an hour. Imaging was completed at baseline and at the end of day 2 of the induced stain regimen. Subjects refrained from any oral hygiene during the two-day stain induction periods. RESULTS: Average baseline L* scores ranged from 76.30 to 76.57. At the end of the two-day stain induction regimen (eight hourly cycles per day) when no gum was chewed ("no gum"), subjects' teeth were 5.18 units darker on average than they were at baseline. At the end of the two-day regimen when the placebo gum was chewed, subjects' teeth were 4.54 units darker on average than they were at baseline. The difference between "no gum" and placebo gum was statistically significant (p = 0.017), and represented a 12.4% reduction in tooth darkness for the placebo gum treatment. Use of the 2.0% Na Hex gum resulted in teeth 3.64 units darker on average versus baseline, and the 3.0% Na Hex gum resulted in teeth 4.02 units darker. Both the 2.0% and 3.0% Na Hex gums resulted in teeth that were statistically significantly less dark (p < or = 0.042) than both the "no gum" and placebo gum treatments. On average, the reduction in tooth darkness for the 2.0% Na Hex gum was 29.7% versus "no gum" and 19.8% versus the placebo gum. The 2.0% Na Hex and 3.0% Na Hex gum treatments did not differ significantly (p = 0.114). CONCLUSION: This study demonstrated that 2.0% and 3.0% levels of Na Hex in a chewing gum prevented the deposition of extrinsic dental stain better than a chewing gum without Na Hex, which in turn prevented the deposition of stain better than no chewing gum.