|Year : 2018 | Volume
| Issue : 1 | Page : 78-82
Comparative evaluation of enamel abrasivity of different commercially available dentifrices – An In vitro Study
Rupali Athawale, SK Srinath, Chandralekha Chowdary
Department of Pedodontics and Preventive Dentistry, Government Dental College and Research Institute, Bengaluru, Karnataka, India
|Date of Submission||24-Nov-2017|
|Date of Acceptance||14-Feb-2018|
|Date of Web Publication||23-Mar-2018|
Dr. Chandralekha Chowdary
Department of Pedodontics, Government Dental College and Research Institute, Room No. 5, KR Market, Bengaluru - 560 002, Karnataka
Source of Support: None, Conflict of Interest: None
Background: Toothbrushing with toothpaste is a major contributor to dental abrasion. A number of factors such as abrasivity and concentration of the toothpaste, brushing frequency, brushing duration, force of brushing, and toothbrush bristle stiffness have a potential impact on the abrasion process of dental hard tissue. However, the abrasivity of the toothpaste is the most important parameter that affects the abrasion process of dental hard tissue. Aims: This study aims to evaluate the maximum and mean enamel abrasivity of commercially available dentifrices such as Colgate total®, Pepsodent whitening®, Vicco vajradanti®, Dabur red® in primary and permanent teeth. Materials and Methods: Human extracted 60 primary and 60 permanent teeth were randomly selected based on the inclusion criteria. Teeth were sectioned at cementoenamel junction using diamond disc and mounted in an acrylic resin blocks. Baseline profilometric measurements were recorded for all the samples. Four commonly used dentifrices were selected and labeled as Group A (Colgate Total®), B (Pepsodent Whitening®), C (Vicco Vajradanti®), and D (Dabur Red®). Toothpaste slurry was prepared. Tooth specimens were brushed in vitro using a customized brushing machine. After toothbrushing, profilometric measurements were obtained, and the differences in readings served as proxy measure to assess surface abrasion. Data were collected and analyzed using student t-test and ANOVA test. Student t-test was used to compare the enamel abrasivity prebrushing and postbrushing, and ANOVA was used to compare the enamel abrasivity among the four different commercially available toothpastes. Results: In permanent teeth, all the toothpastes were found to cause significant enamel abrasion (P = 0.000) and a significant variation was observed when maximum (P = 0.008) and mean (P = 0.036) enamel abrasivity of these toothpastes were compared. In primary teeth also, all the toothpastes caused significant abrasion (P = 0.000); however, when the maximum and mean abrasivity of these toothpastes were compared, no significant variation was observed (P = 0.438 and 0.163). Conclusions: All the commercially available toothpastes cause significant enamel abrasion. Colgate group caused more enamel abrasion whereas pepsodent caused the least enamel abrasion in permanent teeth.
Keywords: Abrasivity, tooth brushing, toothpastes
|How to cite this article:|
Athawale R, Srinath S K, Chowdary C. Comparative evaluation of enamel abrasivity of different commercially available dentifrices – An In vitro Study. J Indian Assoc Public Health Dent 2018;16:78-82
| Introduction|| |
Effective plaque control is critical to the maintenance of oral health because dental plaque is the primary etiological factor in the initiation and development of both caries and periodontal disease. Plaque removal with a manual toothbrush represents the most frequently used method of oral hygiene in Western societies. A toothbrush should be able to reach and clean efficiently most areas of the mouth. The toothbrush is the principal instrument in general use for accomplishing plaque removal as a necessary part of disease control. Many different designs of toothbrushes and supplementary devices have been manufactured and promoted. Depending on the diameter of the bristles, toothbrushes have been categorized as soft (0.2 mm), medium (0.3 mm), and hard (0.4 mm).
Dentifrices have been used in conjunction with toothbrushes since a long time. The use of toothbrush with dentifrice improves the mechanical control of dental plaque. Various studies have found that some degree of abrasivity is needed in toothpaste if satisfactory cleaning of the teeth is to be achieved., On the contrary, some studies have found that toothpaste does not have any contributing effect in the mechanical plaque removal. Besides, regular tooth brushing with dentifrices has been considered an etiological factor in gingival recession and tooth wear as reported by various studies.,
It has been reported, based on several in situ studies, that the mean of enamel loss after 10 years is around 20 μm, which is considered clinically irrelevant. A number of factors have a potential impact on the abrasion process of dental hard tissue. These factors include the abrasivity and concentration of the toothpaste, brushing frequency, brushing duration, force of brushing, and toothbrush bristle stiffness. However, the abrasivity of the toothpaste is the most important parameter that affects the abrasion process of dental hard tissue.
An upper limit of 250 for relative dentin abrasivity (RDA) or 40 for relative enamel abrasivity (REA) for a toothpaste is considered safe for everyday use in adults international organization for standardization (ISO). However, only a few studies are available in the literature evaluating the abrasiveness of different commercially available toothpastes. Further, evidence regarding the abrasivity of toothpastes in children is limited.
To evaluate toothpaste abrasivity, many different techniques have been used, for example, the RDA method, weight and volume loss techniques which are quantitative techniques, measuring the amount of abraded material removed  as well as profilometer and light reflexion techniques, which are qualitative techniques measuring the roughness of the abraded material.,
The mechanism is unclear as to how abrasion varies with the use of different types of toothbrushes and the role of toothpaste in abrasion process. Different in vitro studies have used profilometer to measure surface abrasivity. Profilometer is a device which can measure changes in surface roughness. It provides roughness average (Ra) values for each profile. The profilometer produces a tracing using digital and analogue hardware and software and calculates the average surface roughness (Ra) value for the resultant tracing.,
In the light of these factors, this in vitro study was conducted to assess the enamel abrasivity of different commercially available toothpastes.
| Materials and Methods|| |
The cross-sectional evaluation was undertaken in the Department of Pedodontics and Preventive dentistry from 2015 to 2016. Sample size estimation was done using G * power software. With reference to the previous study, calculated mean surface roughness difference of 0.60 Ra, (1-β =0.80, α =5%) and 0.40 (medium) effect size for multiple comparison, a minimum of 60 primary and 60 permanent human extracted teeth were required to conduct the study. The study was approved by Institutional Ethical Committee. The samples were collected and stored in a formalin solution until use. Teeth with intact crown structure extracted due to trauma, serial extraction are included in this study, whereas teeth with hypoplasia, fluorosis, caries, fracture, decalcification, and restoration were excluded from the study.
Preparation of acrylic plates with enamel specimens
Totally, 120 teeth were sectioned at cementoenamel junction using diamond disc and mounted in an acrylic resin blocks in such a way that labial surface was 2 mm above and parallel to resin block surface.
Any stains, food debris, and calculus adhering to the mounted specimens were cleared off. They were further divided into four groups, each group consisting of 15 primary and 15 permanent teeth specimen, for four different toothpastes.
To check the role of different dentifrice in abrasion process, a standard four commonly used dentifrices were selected and labelled as Group A (Colgate Total ®), B (Pepsodent Whitening ®), C (Vicco Vajradanti ®), and D (Dabur Red ®) [Table 1].
Slurry of the dentifrice was prepared by dissolving 20 g of each toothpaste in 40 ml of water for 5 min and mixed with 10 ml of artificial saliva, and it was spread over the mounted enamel specimens using a measuring scoop before tooth brushing. Each time equal amount of slurry was applied. It was placed over the enamel surface and gently spread over the surface using the toothbrush bristle tips.
Brushing duration and frequency
Brushing was carried out using a new medium bristles toothbrush for each mounted specimens for 2 min, twice a day, for 6 days. Toothbrush head and tooth specimen blocks were adjusted to apply 180 ± 20 g force on samples with approximate 4000 strokes and a speed of 170 rpm.
Construction of customized brushing model
To deliver uniform force in unidirectional motion, a brushing model was fabricated under expert guidance. The customized brushing model comprised of a motor (Wexco; New Jersey, USA), handle, and a wooden base. This device was electrically operated. The apparatus had a screw and wedge design that facilitated easy replacement of one type of toothbrush with other [Figure 1].
The tension of the spring was adjusted using Dontrix Gauge (GAC International; Bohemia, New York, USA). The force was maintained at 180 ± 20 g., This force range was selected as it is the normal force which people apply manually during tooth brushing. The Dontrix gauge was used to adjust the tension periodically.
The mean surface loss was evaluated using a profilometer. It provides Ra value (average surface roughness) and difference in Ra value before and after toothbrushing provides proxy measure for assessing surface abrasion. The Ra value for all the 120 mounted enamel specimens were calculated prior and post to tooth brushing and the difference in Ra value (post and pre) was used to assess change in surface roughness/abrasion [Figure 1].
The profilometric analysis of all the 120 mounted enamel specimens was carried out before toothbrushing. The mean surface roughness value was then calculated for each group. The mounted enamel specimens were then firmly fixed over the wooden base.
The apparatus was so designed that it facilitated only unidirectional movement. No lateral movement was allowed. Slurry of dentifrice was spread over the specimens. The pressure was checked using Dontrix gauge. After this, brushing was carried out for the fixed duration and fixed time period in a direction perpendicular to the long axis of the tooth with a uniform force.
After all the specimens were brushed, all specimens of all the four groups were resent to the laboratory for profilometric analysis, and the Ra values were rerecorded. The differences in profilometric readings (postbrushing and prebrushing) were computed and mean values were calculated and compared. This difference in surface roughness change was used as a proxy measure to assess abrasion.
Paired student t-test was used to compare the enamel abrasivity prebrushing and postbrushing and one way ANOVA was used to compare the enamel abrasivity among the four different commercially available toothpastes.
| Results|| |
There was a significant difference in the maximum enamel abrasivity among all the groups before and after brushing (P< 0.001). Maximum difference in enamel abrasion was highest for Group A (0.20) and least for Group B (0.08) [Table 2]
|Table 2: Maximum enamel abrasivity caused by toothpastes in permanent teeth|
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There was significant difference in the mean enamel abrasivity among all the groups before and after brushing (P< 0.001). Maximum difference in enamel abrasion was highest for Group A (0.15) and least for Group B (0.06) [Table 3]
|Table 3: Mean enamel abrasivity caused by toothpastes in permanent teeth|
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There was significant difference in the maximum enamel abrasivity among all the groups before and after brushing (P< 0.001) except for Group C. Maximum difference in enamel abrasion was highest for Group C (0.16) and least for Group A (0.08) [Table 4].
|Table 4: Maximum enamel abrasivity caused by toothpastes in primary teeth|
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There was significant difference in the mean enamel abrasivity among all the groups except for Group C before and after brushing (Group A P < 0.01), (Group B P < 0.001), (Group C P = 0.103), and (Group D P < 0.001). The maximum difference in enamel abrasion was highest for Group D (0.21) and least for Group A (0.06) [Table 5].
| Discussion|| |
Various types of toothpastes available in the market keep the buyer in a state of dilemma as which one to choose, due to the lack of information., Moreover, brushing with dentifrices continues to be the most used and efficient procedure  of self-care in the practice of oral hygiene in most countries. However, besides having potential benefits of dental plaque biofilm removal and improving oral health, the injudicious use of toothpaste and toothbrush in causing injuries to dental hard and soft tissues has also been documented; abrasion being the most common among them.,
Toothpaste makers regularly measure their product's abrasivity. It is necessary for FDA approval and usually is not included in marketing. Abrasivity measurements are given by an RDA value which stands for radioactive dentin abrasion or RDA.
RDA values for common toothpaste: 0–70 = low abrasive, 70–100 = medium abrasive, 100–150 = highly abrasive, and 150–250 = regarded as harmful limit. However, REA values are not mentioned, and information is not available. Hence, this study was undertaken to assess the enamel abrasion caused by brushing using commonly available toothpastes in primary and permanent teeth, and the results of the study are discussed as follows. There are very few studies available on maximum enamel abrasivity in the literature.
In the permanent teeth as shown in [Table 2], the maximum enamel abrasion caused by toothpastes ranged from 76.94 um to 201.84 um. The least maximum enamel abrasion of 76.94 um is observed to be caused by Pepsodent whitening toothpaste ® (Group B) and the highest maximum enamel abrasion of 201.84 um observed to be caused by Colgate Total toothpaste ® (Group A). Compared to the baseline profilometric readings all the commercially available toothpastes caused significant abrasion in permanent teeth. When the maximum abrasivity of these toothpastes was compared, a significant variation was noted.
In the permanent teeth, as shown in [Table 3], the mean enamel abrasion caused by toothpastes is found to be ranged from 56 um to 146 um. The least mean enamel abrasion of 56 um is observed to be caused by Pepsodent whitening toothpaste ® (Group B) and the highest mean enamel abrasion of 146 um observed to be caused by Colgate Total toothpaste ® (Group A). Compared to the baseline profilometric readings all the commercially available toothpastes caused significant abrasion in permanent teeth. On comparing the mean abrasivity of these toothpastes a significant variation was observed. Supporting the results of our study Philpotts et al., found that the mean enamel wear ranged from 0.05 to 0.40 μ, with the highest wear for the highest REA product with 900 brushing strokes. This is in accordance with present study where we used 4000 strokes, which were almost 5 times that of the above study. Daniela Franzo et al. showed that the mean enamel wear ranged from 0.03 to 0.11 μm after 3000 brushing cycles. Pickles et al. showed there were Significant differences between the test products for both enamel abrasion.
In the primary teeth, the maximum enamel abrasion caused by toothpastes is found to be ranged from 79.46 um to 189.9 um. The least maximum enamel abrasion of 79.46 um is observed to be caused by Colgate Total toothpaste ® (Group a) and that of the highest maximum enamel abrasion of 189.9 um observed to be caused by Vicco Vajradanti ® (Group c). Compared to the baseline profilometric readings all the commercially available toothpastes caused significant abrasion in primary teeth.
In the primary teeth, the mean enamel abrasion caused by toothpastes is found to be ranging from 57.3 um to 214.3 um. The least mean enamel abrasion of 57.3 um is observed to be caused by Colgate Total toothpaste ® (Group A) whereas that of the highest mean enamel abrasion of 214.3 um observed to be caused by Dabur Red toothpaste ® (Group D). Compared to the baseline profilometric readings all the commercially available toothpastes caused significant abrasion in permanent teeth.
On comparative analysis, when tested on primary teeth, there was no significant variation found in the abrasivity of four toothpastes both in case of maximum depth and mean depth. Supporting the results of our study Ozalp and Tulunoglu  found no significant difference in terms of brushing depths between artificial carious enamel and brushed sound enamel specimens using chitosan- and propolis-based toothpastes. Furthermore, very few studies available on enamel abrasivity in the literature.
Limitations of the study
- One of the factors that could be of much importance in methodological resemblance of the dental abrasion in vitro researches to its really occurring situation inside the mouth is the simulation of continuous washing action of the saliva and its remineralizing protective effects over the worn surfaces of teeth
- Abrasion test was limited to a fixed number of strokes (4000 strokes). In similar studies, researchers tried to start from lower number of strokes and then proceed to higher rates. Such studies have demonstrated that test results and their level of significance vary with different number of strokes.
| Conclusions|| |
- All commercially available toothpastes causes significant enamel abrasion in permanent as well as primary teeth
- There was a significant variation in the abrasivity of commonly used toothpastes such as Colgate Total ®, Pepsodent Whitening ®, Vicco Vajradanti ®, Dabur Red ® when tested in permanent teeth
- There was no significant variation found in the abrasivity of commonly used toothpastes such as Colgate Total ®, Pepsodent Whitening ®, Vicco Vajradanti ®, Dabur Red ® when tested in primary teeth
- Maximum enamel abrasivity ranged from 76.94 um to 201.84 um in permanent teeth and 79.46 um to 189.9 um in primary teeth. Mean enamel abrasivity ranged from 56 um to 146 um in permanent teeth and 57.3 um to 214.3 um in primary teeth.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]