The Abrasive Effect of Toothpastes Containing Remineralization

Transcription

1 International Journal of Clinical Preventive Dentistry Volume 8, Number 4, December 20 The Abrasive Effect of Toothpastes Containing Remineralization Components Jae-Hyun Ahn 1, Ji-Hye Kim 1, Seung-Chul Shin 2 1 Department of Oral Care, LG Household & Health Care Research Park, Daejeon, 2 Department of Preventive Dentistry, College of Dentistry, Dankook University, Cheonan, Korea Objective: The purpose of this study was to investigate the abrasive effect of tootpastes containing remineralization components. Methods: The remineralization ingredients such as fluorides (T1: NaF 1,000 ppm F, T2: SMFP 1,000 ppm F), fluoride with potassium dihydrogen phosphate and dipotassium hydrogen phosphate (T3) were applied to the toothpastes having same compositions and same abrasivity. The hardness of dentin surface (VHN), dentin abrasivity and abrasion depth, cleaning power and physicochemical surface changes of the dentin surface (SEM / EDS) were evaluated in vitro with a control toothpaste without remineralization ingredients. Results: All the Experimental toothpastes containing fluoride (T1-T3) significantly increased the micro-hardness of dentin specimen compared with the control toothpaste. The toothpaste containing two kinds of potassium orthophosphates with fluoride (T3) significantly increased hardness of dentin specimen compared with the fluoride containing toothpastes (T1-T2). Coexistence with fluorides and two kinds of potassium orthophosphates in toothpastes could reduce significantly dentin abrasivity and abrasion depth (p<0.05). However, cleaning power among toothpastes having different abrasivity from the dentin remineralization effect was not significantly different (p>0.05). Conclusion: Dentin abrasion by brushing could be reduced by using fluoride, monopotassium phosphate and dipotassium phosphate in toothpaste without changing of cleaning power. Keywords: toothpaste, remineralization, abrasivity, wear, cleaning power Introduction Corresponding author Jae-Hyun Ahn LG Household & Health Care Research Park, 84 Jangdong, Yusung-gu, Daejeon , Korea. Tel: , Fax: , jhahnjhahn@ hanmail.net Received December, 4, 20, Revised December, 13, 20, Accepted December, 13, 20 The function of toothpaste is to remove plaque physically on the surface of teeth, but studies on the efficacy for toothpaste containing various pharmacological active ingredients such as anti-bacterial, anti-inflammatory or remineralization materials have been done more since the invention of fluoride. The various studies of fluoride type and concentration have been done since the 1940s and the fluoride containing toothpaste was firstly merchandised in 1955 and approved by American Dental Association (ADA) in the 1960s for the effectiveness of the prevention of dental caries (1). The conception of tooth remineralization began to be introduced from the research of fluoride toothpaste and various materials like phosphates and calcium salt with fluoride have been studied since the late '70s (2). Fluoride containing toothpaste was classified as the OTC (over the count) drug by the Food & Drug Safety Administration (FDA) due to the efficacy of fluoride in the United States, similarly, as a semi-drug in Japan and South Korea and cosmetics in Europe. Although there is a little bit difference according to the country, fluoride ingredients in toothpaste are regarded as an active ingredient and controlled strictly in terms of the fluo- 215

2 International Journal of Clinical Preventive Dentistry ride kinds and the amount (3-6). The abrasivity of toothpaste is changeable according to the brushing environment such as the kinds of toothbrushes, brushing method and brushing pressure and so on depending on individuals but in general, the high abrasive toothpaste has the high cleaning power (7). It is cautious that people who have sensitive teeth by the gingival recession or the marginal tooth wear use high abrasive toothpaste. However, it can be more cautious for people who have healthy teeth to use too much low abrasive toothpaste not to remove plaque properly because the residual plaque causes dental caries by the bacteria and chronic gingivitis by the plaque calcification process (8). In this sense, the proper abrasivity of toothpaste is a very important factor but abrasivity information is not represented on the package of the toothpastes worldwide. Dental plaque can be removed by brushing without using toothpaste but it was not effective compared with using toothpaste according to the Dudding study (9). The global standard (ISO), British Standard, and American Dental Association announce only the upper limit values compared with standards toothpaste (defined 100) by the radio trace method and the surface profile method. The global standard (ISO 11609) recommends 2 to 2.5 times less for the dentin, 2 to 4 times less for the enamel as the upper limit of abrasivity value according to the measurement methods (10). The British Standard (BS 5136) represents 2 and 4 times less as the upper limit of abrasivity value for the dentin and enamel each compared with standards toothpaste (11). On the previous research related with tooth abrasion, Miller et al. () study about the abrasion of the tooth powder was the first and a lot of studies were about how to measure the abrasivity of toothpaste. Today, the radio trace method made by Hefferren (13) and the surface profile method offered by Ashmore (14) have been used around the world. Liljeborg (15) reported the surface profile method was useful in terms of getting not only the quantitative result but also the qualitative result like the surface roughness on the tooth surface brushed. Franzo et al. (16) studied the degree of tooth abrasion with the various concentrations of toothpaste and brushing time. In addition, Philpotts et al. (17) compared the degree of tooth abrasion for different abrasive toothpaste using human teeth and Hooper et al. (18) and Kim et al. (19) evaluated the influence of abrasion with an acidic beverage. Meanwhile, Murray et al. (20) observed clinically DMFS changes due to using different abrasive toothpaste with fluoride for 3 years for elementary school students. Parry et al. (21) specifically designed in vitro devices and evaluated the degree of enamel and dentin abrasion in accordance with the brushing force, speed, and temperature changes. In addition, there were studies regarding the abrasivity comparison of commercialized Toothpaste, the compared research between the assessment methods to measure the abrasivity of toothpaste or the suitability for a newly developed toothpaste (22,23). Over recent years, one of the issues for the toothpaste has been the remineralization effects and the purpose of enhancing remineralization effects is to harden teeth to increase acid resistance. In line with this, the higher remineralizing toothpaste may be the lower abrasive toothpaste due to its hardening effect for teeth. The enamel specimens have been used in the acid resistance or hardness change studies related with dental caries and the dentin specimens have been used in the scanning electron microscopy (SEM) observation studies related with hypersensitivity teeth by sealing of dentinal tubules (24,25). However, the study for the relationship between the remineralization effect of toothpaste and the abrasivity of toothpaste is very rare. Bartlett et al. (26) and Anderson et al. (27) research were just comparing evaluation about fluoride-containing and non-containing toothpaste in laboratory. Moore et al. (28) studied the degree of dental wear under the changes of the abrasive agents and surfactant combination in toothpastes. This study was designed in the hypothesis that when abrasive ingredient is constant in toothpaste, it may have constant cleaning power and if the hardness of the dentin surface is increased by the action of the remineralization of toothpaste while brushing, dentin abrasion by brushing will be reduced. Material and Methods 1. Materials 1) Dentin specimen The specimens used in this experiment were recently extracted caries-free human molar permanent teeth and soft tissue was removed. They were washed with distilled water, dipped in 0.1% Thymol solution, and kept in the refrigerator. The cervical parts of teeth were cut in cross-sectional and longitudinal direction with a diamond wheel disk. After the shape of specimen was made for dentinal tubules hole to be exposed to the surface by using the 2 2 cm brass mould and epoxy resin, they were ground and polished below 1.0 μm of surface smoothness (Surface Profile Meter: Mitutoyo SV-3000, Japan) by using a lapping machine (Grinder Metaserv 2000) and silicon carbamide papers (# 200, # 400, # 600, # 800, # 00). 2) Hydroxyapatite (HAP) specimen Hydroxyapatite powder (Wako Chemical) and 3% solution of polyvinyl alcohol were mixed, dried at 80 o C for 2-3 hours and crushed g of crushed powder was weighed, pressed for 1 minute about 4.2 tons pressure with an IR press, HAP tablet (.5 mm diameter, 1.8 mm thick) was made and sintered at 216 Vol. 8, No. 4, December 20

3 Jae-Hyun Ahn, et al:the Abrasive Effect of Toothpastes Containing Remineralization Components 1,000 o C. The shape of the HAP specimen was made by using the 2 2 cm brass mould and epoxy resin then. For staining on HAP surface, the HAP specimens were etched with 1% hydrochloric acid solution, positioned in the staining machine illuminated with a incandescent ramp, stained for five days with staining solution that composed of 7.4 g of mixture of coffee, tea, mucin powder at a ratio of 8:8:6, 1.6 g of FeCl 3 and 30 ml of Sarcina lutea incubation solution in the 800 ml of sterile Typticase Soy Broth (TSB: DIFCO) solution. The HAP specimens used in this experiment were less than 50 of the initial L value (lightness index). 3) Preparation of toothpastes All of the toothpastes were made in a same formula except the remineralizing components and dental type silica supplied commercially from the Rhodia company (French) was used as an abrasive agent. Table 1 shows each toothpaste composition. The viscosity and ph of final products were 70,000 to 80,000 cps and 7.0 to 7.5 at 25 o C which are similar to marketed toothpastes. 4) Preparation of artificial saliva Potassium chloride (KCl) mg, Sodium chloride (NaCl) mg, Potassium phosphate dibasic (K 2HPO 4) 33.8 mg, Magnesium chloride (MgCl 2 ) 59.6 mg, and Calcium chloride dehydrate (CaCl 2) mg were dissolved in 1,000 ml distilled water. 5) Preparation of acid solution After Lactic acid g was weighed into a 1 L volumetric flask with distilled water (1 M sol.), 0.1 M solution was made by diluting with distilled water. Then the ph 5.0 of solution was adjusted with 50% NaOH. 2. Methods 1) Vickers hardness Dentin specimens were treated in a solution of 0.1 M lactic acid Table 1. Composition of experimental toothpastes Groups Abrasive contents Remineralization components Control toothpaste Toothpaste 1 Toothpaste 2 Toothpaste 3 Silica 15.0%* Silica 15.0% Silica 15.0% Silica 15.0% No fluoride NaF 0.22% (1,000 ppm as F ion) SMFP** 0.76% (1,000 ppm as F ion) NaF 0.22% (1,000 ppm as F ion) +KH 2PO 4 (2.0%)+K 2HPO 4 (3.0%) *Silica is Dental Type Silica (Rhodia, Tix-O-Sil 73K). **SMFP is Sodium Monofluorophosphate. All of the materials meet USP (United States Pharmacopeia) specification and KP (Korean Pharmacopeia). (ph 5.0) for 0 min in other to demineralize the surface of dentin. Vickers hardness of dentin surface (AKASHI MVK-E, Japan) was measured in the condition of 200 g load each four areas on the surface of the specimens for five seconds. The specimens in the range of 45 to 55 Vickers hardness number were selected and distributed to each experimental toothpaste groups without statistical significance. Dentin specimens were stirred for 30 minutes with a shaker in 2:1 mixture slurries of artificial saliva solution and each of toothpaste. Vickers hardness of dentin surface before and after treatment was measured for 5 seconds with a load of 200 g. 2) Dentin abrasivity and average abrasion depth The method used in this experiment was based on the surface profile method (BS 5136) (11) to quantify the degree of surface wear. Dentin specimens were stirred for 30 minutes with a shaker in 2:1 mixture slurries of artificial saliva solution and each of toothpaste. They were washed with distilled water then, dried at room temperature and covered with PVC tape except for the central region of 2 mm wide. Dentin specimens were brushed on 1,000 times round-trip at the speed of 90 rpm under the 250 g load using same toothpaste slurry (29). 20 ml of artificial saliva was added for every 200 times of brushing. After brushing, specimens were dried at room temperature and surface roughness was measured with surface profile meter (Mitutoyo SV-3000, Japan). Dentin abrasion area as cross-sectional area of dentin was measured. After the same procedure on the standard toothpaste was conducted, Relative dentin abrasivities on the each experimental toothpaste were calculated compared with the area of the standard toothpaste. Abrasion area of experimental toothpaste Relative dentin abrasivity = 100 Abrasion area of standard toothpaste Average abrasion depth was measured and calculated from the plots of the wear surface by dividing the full length of the wear surface area into 10 same parts, summing the length of 9 places except the both end length of ten parts, and dividing by 9. 3) Cleaning power Cleaning power was measured by modified Stookey method (PCR: Pellicle cleaning ratio) (30). Artificially stained hydroxyapatite (HAP) specimens were prepared and initial lightness values were measured with a colorimeter (Minolta CR-321 Japan). Hydroxyapatite (HAP) specimens were distributed to each experimental toothpaste group without statistical significance and brushed for 1hour (5,400 double strokes) under IJCPD 217

4 International Journal of Clinical Preventive Dentistry 250 g load at the rate of 90 double strokes per minute in 2:1 mixture slurries of artificial saliva solution and each toothpaste. Lightness values after brushing were measured and the differences of before and after lightness values were calculated. 4) SEM / EDS Dentin specimens were stirred for 30 minutes with a shaker in 2:1 mixture slurries of artificial saliva solution and each of toothpaste, washed with distilled water for 30 minutes, and dried at room temperature. The surfaces of dentin specimens were coated with sputtering Iridium particles for 5 minutes using an ion beam coater (GATAN) and observed at 2,000 and 5,000 times with SEM/EDS (Scanning Electron Microscope/ Energy Dispersive Spectrometer: Hitachi S-4800) at the 15 kv acceleration voltage and the 15μA Emission Current. 3. Statistical analysis All experimental data were analyzed by statistical program SPSS 20.0 (SPSS Inc. USA) at the significance level of α = Analysis of variance (One-way ANOVA) and Scheffe's multiple-comparison method were conducted to see the statistical significance among the effects of the each toothpaste. Results 1. Vickers hardness All the experimental toothpastes containing fluoride significantly increased the hardness of dentin specimen compared with the control toothpaste. The toothpaste containing two kinds of potassium orthophosphates with fluoride significantly increased hardness of dentin specimen compared with the fluoride containing toothpastes. However, there was no statistical significance between toothpaste containing sodium fluoride (1,000 ppm as F) and toothpaste containing sodium monofluorophosphate (1,000 ppm as F) (Table 2). Table 2. The change of surface hardness value (VHN) by experimental toothpastes Groups N Pre-treatment Post-treatment ΔVHN Control toothpaste Toothpaste 1 Toothpaste 2 Toothpaste ± ± ± ± ± ± ± ± ±1.70 a 0.50±1.72 b 0.32±2.85 b 4.22±3.39 c Values are means±standard deviation. ΔVHN was determined by one way ANOVA analysis among groups. a-c The same characters are not statistically significant by Scheffe multiple comparison at α= Abrasivity and abrasion depth The results of abrasivity measured by the surface profile method (14) were as follows. The control toothpaste without fluoride showed the highest abrasivity value of 54.99±5.10 and toothpaste 3 containing fluoride and potassium orthophosphate showed the lowest abrasivity value of 23.10±3.62. Abrasivity of toothpaste 2 containing sodium monofluorophosphate (1,000 ppm as F) was 49.17±4.56 and Abrasivity of toothpaste 1 containing sodium fluoride (1,000 ppm as F) was 47.67±5.23 each. In the statistical analysis, toothpaste 3 containing fluoride and potassium orthophosphate was significantly different compared with control toothpaste. The results of average abrasion depth were similar to those of abrasivity and toothpaste 3 containing fluoride and potassium orthophosphate was only significantly different compared with control toothpaste (Table 3, Figure 1). 3. Cleaning power The range of cleaning power for all of the experimental toothpastes was 9.54 to.13 and there were no statistical significances among them (Table 4). 4. Surface analysis The surface of dentin specimen treated by toothpaste 3 containing fluoride and orthophosphate (NaF 0.22%+KH 2PO 4 2.0% + K 2 HPO 4 3.0%), which was significantly increased the hardness values, was analyzed with SEM / EDS. Untreated dentin specimen and control one were compared together (Figure 2, 3). There were no sealed dentinal tubules at the surface of dentin specimen treated by control toothpaste without fluoride but more than half of dentinal tubules were sealed at the surface of dentin specimen treated by toothpaste 3. In the elemental analysis with EDS, potassium (K) originated from potassium orthophosphate was detected. Table 3. Abrasivity value and average abrasion depth by experimental toothpastes Groups N Abrasivity (SPM) Control toothpaste Toothpaste 1 Toothpaste 2 Toothpaste ±5.10 a 47.67±5.23 a 49.17±4.56 a 23.10±3.62 b Average abrasion depth (μm) 4.33±1.22 a 3.78±0.67 a 4.00±1.05 a 2.28±0.54 b Values are means±standard deviation. Abrasivity and average abrasion depth were determined by one way ANOVA analysis among groups. a-b The same characters are not statistically significant by Scheffe multiple comparison at α= Vol. 8, No. 4, December 20

5 Jae-Hyun Ahn, et al The Abrasive Effect of Toothpastes Containing Remineralization Components Figure 1. Abrasivity area of experimental toothpastes. Figure 2. SEM of dentine surfaces of without treatment, control toothpaste, toothpaste 3 at 2,000 (left) and 5,000 magnification (right). Table 4. Cleaning power (PCR) of experimental toothpastes Groups Control toothpaste Toothpaste 1 Toothpaste 2 Toothpaste 3 N Pre-treatment Post-treatment 31.53± ± ± ±3.10 ΔL value a 43.39± ±1.17 a 44.06± ±2.29 a 43.76± ±1.08 a 53.73± ±2.01 Values are means±standard deviation. ΔL value was determined by one way ANOVA analysis among groups. athe same character is not statistically significant by Scheffe multiple comparison at α=0.05. Discussion The main purpose of using toothpaste is plaque control and oral cleansing. Additionally, it delivers active ingredients like fluoride to prevent oral disease such as dental caries or gingivitis. The function of fluoride in toothpaste is remineralization effect to harden the surface of teeth. To increase cleaning effect of toothpaste, increasing abrasivity is a general method by controlling the kinds and content of abrasive agent in toothpaste formulation. However, this method is not good way because high abrasivity makes teeth worn out more. We have to use our teeth for more than 70 years until die. In this respect, when abrasive representing physical cleaning effect is constant in toothpaste, it has constant cleaning power and if the hardness of the dentin surface is increased by the action of the remineralization of toothpaste, dentin abrasion may be decreased while brushing. As a previous research supporting this assumption, Bartlett et al. (26) have collected premolar from water fluoridated and non fluoridated regions, evaluated fluorine content and the hardness of teeth, and announced that the fluoride-containing toothpaste inhibited experimentally enamel abrasion about 1.7 times than the fluoride free toothpaste at the same abrasivity. Anderson et al. (27) have designed several toothpastes having different abrasivity, evaluated enamel and dentin abrasion with fluoride and non-fluoride at each abrasivity and reported that fluoride in toothpaste could reduce enamel and dentin abrasion. Kielbassa et al. (31) have researched abrasion depth measured by the radio trace method (RDA) using a bovine teeth. Remineralization ingredients used in this study were the type of fluoride (sodium fluoride, sodium monofluorophosphate) and potassium orthophosphates (monopotassium phosphate, dipotassium phosphate). Firstly, we compared the hardness changes after treatment on each of toothpastes having different remineralization system. Looking at the results of the research, hardness value (VHN) in control toothpaste before and after treatment was 51.24±6.66 and 47.±6.19 each. Hardness value was decreased in control toothpaste consisting of only basic ingredients without remineralization ingredients. It could be explained that the surfactants ingredients like sodium lauryl sulfate influenced on the dentin surface and dentinal tubules to IJCPD 219

6 International Journal of Clinical Preventive Dentistry Figure 3. EDS spectrum of dentine surfaces of without treatment, control toothpaste, toothpaste 3. decrease the hardness of dentin just like Moore research (28) that surfactants in toothpaste can promote the degree of abrasion on brushing. There was no statistical significance between sodium fluoride containing toothpaste (T1) and sodium monofluorophosphate containing toothpaste (T2) in terms of hardness changes of dentin specimen (p>0.05). But compared with the control toothpaste, both toothpaste (T1,T2) increased the hardness of dentin significantly (p<0.05). The specimen treated by toothpaste 3 containing potassium orthophosphates (monopotassium phosphate, dipotassium phosphate) with Sodium fluoride showed higher increase of hardness compared with the specimen treated by sodium fluoride containing toothpaste (T1) and sodium monofluorophosphate containing toothpaste (T2) (p<0.05). This result met the previous studies that coexistence of phosphates with fluoride could enhance the increase of dentin hardness (32). In addition, SEM finding on the surface of dentin and analysis results of EDS after treatment backed up these results. The reaction equations of remineralization commonly known (32,33) can be summarized as Figure 4 and can be interpreted as the reverse reaction of demineralization that cause tooth decay. Reaction 1 represents the reaction of demineralization and soluble calcium ions react with phosphate ions step by step like reaction 2 and 3. It is known that the remineralization reaction is somewhat more complex and the reaction move to forward direction at the ph above 6.2. As the precursor of hydroxyapatite formation in the process of remineralization, octacalcium phosphate (OCP) and amorphous calcium phosphate (ACP) theory are known (32,33). On the other hand, unlike enamel, the content of inorganic materials of dentin is composed of 60-70% level and the rest are kinds of proteins, type 1 collagen and phosphophoryn etcetera. Dentin surface is strongly charged negatively because of carboxylic ion and phosphate ion due to aspartic acid and phosphoserine which consist of phosphophoryn at the upper isoelectric point of ph 1.1. The calcium cation in saliva easily reacts with these anions on the dentin surface. The organic matter such as aspartic acid and phosphoserine must be involved in the remineralization process of dentin. The evaluation method of toothpaste abrasivity with human subject has not yet been developed because there are various changing factors such as brushing method, brushing time, brushing pressure, and kinds of toothbrushes in addition to abrasivity of toothpaste itself. In this study, abrasivity and abrasion depth for human dentin were analyzed using the surface profile method based on British Standard. It is good way to evaluate abrasivity of toothpaste using enamel surface because abrasion action occur on the surface of enamel primarily. However, dentin specimens were used in this study because it was very difficult to identify the degree of abrasion using enamel which was too hard to wear relatively compared with dentin according to previous study and it was easy to obtain more discriminative results in terms of the degree of abrasion using dentin. According to the results of toothpaste abrasivity for dentin specimen, the abrasivity of control toothpaste was 54.99±2.10. When calculating the reduction rate of each toothpaste based on the abrasivity of control toothpaste, toothpaste (T2) 10.6%, toothpaste (T1) 13.3%, and toothpaste (T3) 58.0% 220 Vol. 8, No. 4, December 20

7 Jae-Hyun Ahn, et al:the Abrasive Effect of Toothpastes Containing Remineralization Components Figure 4. Reaction mechanism of demineralization and remineralization. Figure 5. Plots of abrasivity, abrasion depth, and cleaning power with ΔVHN. were shown in this order. These results showed that the hardness increase after treatment of toothpaste, namely, remineralization effects were very related with the decrease of toothpaste abrasivity. The reduction rate of abrasion depth for each toothpaste based on the abrasion depth of control toothpaste were shown in the following order of toothpaste (T2) 7.6%, toothpaste (T1).7% and toothpaste (T3) 35.8%. Because the results of abrasion depth were the calculated values from abrasivity results of plots form, the similar pattern showed in terms of relationship between the remineralization effect in toothpaste and the degree of dentin abrasion. The toothpaste (T3) containing two kinds of potassium orthophosphates with fluoride only showed the statistical difference compared with the control toothpaste in the point of the reducing abrasivity of toothpaste and abrasion depth when brushing. The higher abrasivity of toothpaste represents the higher cleaning power in general but the composition of toothpaste can make different pattern depending on the design. According to the study of Wulknitz et al. (7) who studied the correlation between dentin abrasivity and cleaning power (Pellicle cleaning ratio) in the 41 kinds of toothpastes which were commercially available in Europe, the correlation coefficient (r value) was 0.66 which meant positively correlated with overall but the various aspects showed depending on the composition of toothpastes. Klüppel et al. (34) claimed that the low abrasivity and high cleaning power toothpaste could be made through the controlling of the composition of toothpastes. The abrasivity of toothpaste was related with not only the physical properties like kinds of abrasives but also the chemical properties like detergents or remineralizing agents in toothpaste. The results of cleaning power obtained in this study showed similar in this respect. All of the ingredients except the remineralizing agents like fluoride or phosphates were same in all toothpastes including the control toothpaste so that the cleaning powers of them were almost same. However, the abrasivity and abrasion depth were dramatically different in proportion to the degree of the remineralization effect of the toothpastes. The relationship among abrasivity, abrasion depth and cleaning power according to the remineralization effect represented at Figure 5. In short, the higher remineralization effect in toothpaste got the less abrasivity and abrasion depth but same cleaning power. However, the limitations of this study, all results will be evaluated by a laboratory method and the experiment design was also in the accelerated conditions in order to get results in a short time. In the future, based on the results of this study, the evaluation using a ph cycling system which mimics oral environment or clinical evaluation should be considered. Conclusion To investigate the abrasivity and cleaning effect of toothpastes containing remineralization components such as fluoride and orthophosphates, the authors evaluated the change of hardness (remineralization), abrasivity and abrasion depth, cleaning power, and surface property of dentin for the fluoride toothpaste IJCPD 221

8 International Journal of Clinical Preventive Dentistry and fluoride toothpaste with orthophosphates compared with the control toothpaste. The obtained results were as follows. 1. All the experimental toothpastes containing fluoride (T1- T3) significantly increased the hardness of dentin specimen compared with the control toothpaste (p<0.05). 2. Toothpaste containing fluoride with monopotassium phosphate and dipotassium phosphate (T3) significantly increased the hardness of dentin specimen compared with the fluoride-containing only toothpaste (T1, T2) (p<0.05). 3. Toothpastes containing fluoride with monopotassium phosphate and dipotassium phosphate (T3) significantly reduced dentin abrasivity and abrasion depth (p<0.05) but fluoride-containing only toothpaste didn t reduce dentin abrasivity and abrasion depth (p>0.05). 4. There were no significant differences in the cleaning power among all of the toothpaste having different abrasivity due to dentin remineralization effect (p>0.05). In conclusion, dentin abrasion by brushing could be reduced by using fluoride, monopotassium phosphate and dipotassium phosphate in toothpaste without changing of cleaning power. References 1. Denis O Mullane. Contribution of fluoride toothpaste to oral health. Ireland: The Royal Society of Medicine Press; 1995: Schemehorn BR, Orban JC, Wood GD, Fischer GM. Remineralization by fluoride enhanced with calcium and phosphate ingredients. J Clin Dent 1999;10: Pharmaceutical Law Health Ministry. Korea Code of Federal Regulation Food and Drug Administration edition: Pinko RG, Rubin PD. The food and drug administration s regulation of dental products. J Clin Dent 1996;6(3): Manufacturing and Sales guidebook for cosmetic and quasi drug in Japan. Sisailbo: Japan; 2006: Wiilknitz P. Cleaning power and abrasivity of European toothpaste. Adv Dent Res 1997;11(4): Kang SY, Jo JW, Chang YS. An experimental study on cervical abrasion of the tooth surface by toothbrushing with horizontal scrub. Int Clin Prev Dent 2007;3(2): Dudding NJ, Dahl LO, Muhler JC. Patient reactions to brushing teeth with water, dentifrice, or salt and soda. J Perio 1960: International standard Organization ISO 11609, International standard dentistry-toothpaste-requirements, test methods and marking ISO Geneva Swizerland British standard institution specification for toothpaste. BS 5136, Miller WD. Experiments and observations on the wasting of tooth tissue variously designated as erosion, abrasion, chemical abrasion, denudation, etc. Dent Cosmos 1907;2: Hefferren JJ. A laboratory method for assessment of dentifrice abrasivity. J Dent Res 1976;55(4): Ashmore H, Van NJ, Wilson SJ. The measurement in vitro of dentine abrasion by toothpaste. Br Dent J 1972;133: Liljeborg A, Tellefsen G, Johannsen G. The use of a profilometer for both quantitative and qualitative measurements of toothpaste abrasivity. Int J Dent Hygiene 2010;8: Franzo D, Philpotts CJ, Cox TF, Joiner A. The effect of toothpaste concentration on enamel and dentine wear in vitro. J Dentistry 2010;38: Philpotts CJ, Weader E, Joiner A. The measurement in vitro of enamel and dentine wear by toothpastes of different abrasivity. Int Dent J 2005;55(3): Hooper S, West NX, Pickles MJ, Joiner A, Newcombse RG, Addy M. Investigation of erosion and abrasion on enamel and dentine: a model in situ using toothpastes of different abrasivity. J Clin Perio 2003;30: Kim YH, Lee JY, Jeong MK. The erosion of the tooth enamel and the cementum by carbonate beverage. Int Clin Prev Dent 2011;7(1): Murray JJ, Shaw L. A 3-year clinical trial into the effect of fluoride content and toothpaste abrasivity on the caries inhibitory properties of a dentifrice. Com Dent Oral Epide 1980;8(1): Parry J, Harrington E, Rees GD, McNab R, Smith AJ. Control of brushing variables for the in vitro assessment of toothpaste abrasivity using a novel laboratory model. J Dentistry 2008; 36: Barbakow F, Lutz F, Imfeld T. A clinical comparison of dentifrice abrasion scores on dentine recorded by gravimetric and radiotracer methods. J Dentistry 1992;20: Ha JE, Kang YJ, Jin BH, Paik DI, Bae KH. Relative tooth abrasivity of the dentifrices marketed in Korea. J Korean Acad Oral Health 2011;35(1): Lee JR, Mun YH, Jung SJ, Lee MR. SEM findings on the obstruction of the dentinal tubules by fluoride application method. Int J Clin Prev Dent 2010;6(3): Lee CJ, Shin SC, Lee JI. Fluoride bound crystal formation on the tooth by the method and the frequency of fluoride topical application. Int J Clin Prev Dent 2010;6(4): Bartlett DW, Smith BGN, Wilson RF. Comparison of the effect of fluoride and non-fluoride toothpaste on tooth wear in vitro and the influence of enamel fluoride concentration and hardness of enamel. Br Dent J 1994;176: Anderson TH, Carlos GC, Jonathan C, Madhu P, Geoorge JE, Domenick TZ. Interplay between fluoride and abrasivity of dentifrices on dental erosion-abrasion. J Dentistry 2009;37: Moore C, Addy M. Wear of dentine in vitro by toothpaste abrasives and detergents alone and combined. J Clin Perio 2005;32: Lee KH, Lee CH, Choi YH. Clinical study on toothbrushing forces. Int J Clin Prev Dent 2007;3(2): Stookey GK, Burkhard TA, Schemehorn BR. In vitro removal of stain with dentifrices. J Dent Res 1982;61: Vol. 8, No. 4, December 20

9 Jae-Hyun Ahn, et al:the Abrasive Effect of Toothpastes Containing Remineralization Components 31. Kielbassa AM, Gillmann L, Zantner C, Meyer L, Hellwig E, Schulte J. Profilometric and microradiographic studies on the effects of toothpaste and acidic gel abrasivity on sound and demineralized bovine dental enamel. Car Res 2005;39: Kashtal S. Historical review of remineralization research. J Clin Dent 1999;10: Park KK. Oral biochemistry. 1st ed. Seoul: Kunja Publishing; 1994:80-103, Klüppel HJ, Plöger W, Förg F, Umbach W. Parameters for assessing the cleaning power of toothpastes. J Soc Cosmet Chem 1986;37: IJCPD 223