Toothpaste-related interests of Google users from different countries

Abstract

The Internet is a growing source of knowledge and can provide information about oral health. This ecological study aimed to characterize the interests in toothpaste among Google users from different countries. Our hypothesis was that there would be an increase in Google users’ interest in information about toothpaste. This retrospective longitudinal ecological study analyzed the toothpaste-related interest of Google users from 10 countries between January 2004 and December 2020. The monthly variation in relative search volume (RSV) and the main related queries were determined using Google Trends. Autoregressive integrated moving average (ARIMA) forecasting models were built to establish the predictive RSV values for toothpaste for an additional 12 months. Autocorrelation plots and the generalized additive model (GAM) were used to diagnose trends and seasonality in RSV curves. Additionally, the influence of social isolation related to the outbreak of COVID-19 was analyzed. Although not detected by autocorrelation function (ACF) and partial autocorrelation function (PACF) analyses, the heuristic analysis showed an increase in the interest in toothpaste-related information in all countries, with a stable trend observed in the 12-month forecasts, except for the increases in the United Kingdom and South Africa. Also, GAM analyses demonstrated a non-significant monthly or quarterly seasonal influence on data. In addition, social isolation during the COVID-19 pandemic did not influence the online information-seeking behavior of Google Search users linked to this topic. We confirmed the hypothesis that the interest of Google Search users in information about toothpaste increased in all of the 10 assessed countries.

Consumer Health Information; Internet Use; Dental Informatics; COVID-19; Toothpastes

Introduction

Dental biofilm is a major etiological agent of dental caries and gingivitis. Thus, the prevention of both diseases depends on daily self-performed mechanical removal of biofilm. ¹ Mechanical biofilm control consists of a combination of toothbrushing and interdental plaque removal. However, maintaining the tooth surfaces free of plaque is not an easy task, as it requires high levels of motivation and manual dexterity. ² Furthermore, optimal biofilm control requires providing the patient with appropriate tools and correct oral hygiene instructions. Unfortunately, few individuals achieve proper levels of mechanical oral hygiene. ² Consequently, adjunctive chemical plaque control is indicated to provide additional benefits in reducing plaque and gingivitis. ³ Chemical plaque control consists of the delivery of antiseptics by mouthrinse or toothpaste. ³

Delivery of chemical agents with toothpaste is the most logical approach to adjunctive chemical plaque control in that the population commonly uses dentifrices during toothbrushing. ¹ Furthermore, toothpastes are widely accepted and present a reasonable cost. Toothbrushing with a fluoride toothpaste is one of the most important preventive measures to decrease dental caries. ³ In addition, there is evidence of the benefits of other substances found in toothpastes for the reduction of biofilm and gingivitis, such as triclosan/copolymer, stannous fluoride ⁴ and dual-zinc plus arginine. ⁵ Moreover, some products have demonstrated efficacy in root caries reduction, ⁶ dentin hypersensitivity management, ⁷ and protection against abrasive or erosive challenges. ⁸

Given the wide choice of available products and the controversies about oral hygiene in the media, it is natural for patients to search for the best way to promote their routine oral care. ⁹ The internet is an important and popular source of health information. ¹⁰ Unfortunately, the quality of most websites is poor, mainly because much content is produced by non-dental organizations, which present unreliable information about oral health, associated with no awareness or incentive to include evidence-based information. ¹¹ Low-quality information can mislead patients, who can adhere to unproven or deceptive treatments to the detriment of evidence-based healthcare, thus affecting their safety and quality of life ¹² and undermining their trust in dental professionals. ¹¹ In this context, an investigation into oral health searches from various populations may offer insights into the experiences, interests, and behaviors of Internet users when using toothpaste in their daily lives, helping the establishment of oral health communication strategies based on more realistic problems that are not necessarily known by dentists. Consequently, these strategies would be more able to influence and empower individuals to improve self-care for oral health more effectively. In addition, understanding the health-related interests of internet users may reveal the population’s oral health needs and may contribute to public health policy planning. ¹³ , ¹⁴

Considering the importance of toothpastes in routine oral health care, the wide range of products offered by the market, and the needs of each population, this study aimed to characterize the interests in toothpastes among Google users from different countries. Our hypothesis was that there would be an increase in Google users’ interest in information about toothpaste.

Methodology

Study design

This retrospective longitudinal ecological study analyzed the toothpaste-related computational metadata of 10 countries using Google Trends. We followed the methodology of a previous study concerning the selection of countries based on their population size, the percentage of the population with internet access, and their socioeconomic characteristics. ¹⁵ The relative volume search (RSV) and main queries for the topic “toothpaste - subject” from January 2004 to December 2020 were collected and stored on January 22, 2021. The data were analyzed considering (a) search volume trends, (b) the development of forecasting models, (c) seasonality, (d) the most popular related queries, and (e) influence of the COVID-19 outbreak on users’ interests. The methodology and data analysis were based on previous dental surveillance studies. ¹³ - ¹⁶

Ethics

Considering that federal regulations have established that research using publicly available data does not involve human subjects, this study did not require approval by the Institutional Review Board.

Selection of countries

We selected 10 countries according to the following inclusion criteria: (a) socioeconomic development (50% developing and 50% developed countries), (b) >50% of Internet penetration rate, (c) more than 15 million inhabitants, and (d) different continents. ¹³ , ¹⁵ , ¹⁶ The developed countries chosen for data collection were Australia (AUS), Chile (CHL), Japan (JPN), United Kingdom (GBR), and the United States (USA), and the developing countries chosen were Brazil (BRA), Mexico (MEX), Russia (RUS), Saudi Arabia (SAU), and South Africa (ZAF). Countries were used as the independent variable.

Relative search volume (RSV)

The dependent variable of this study is the RSV, which represents the weekly or monthly search volume of a specific query performed by users on Google Search, normalized by the maximum value in a given period (RSV=100). We filtered the metadata by period, source, location, and category. On January 22, 2021, we used the topic “toothpaste - subject” to collect data from the 10 selected countries from January 2004 to December 2020, using the other settings as default (all categories and sources). This topic is the keyword obtained from algorithms developed by Google Trends that filter all keywords linked to the topics of interest.

Main queries

In addition, Google Trends offers a list of the most popular queries used in each country to find information associated with the topic of interest over time. In this sense, the main queries of the topic “toothpaste - subject” were collected, translated, and dichotomized to identify the toothpaste-related subjects.

Data analyses

We used the Statistical Package for Social Sciences software (version 22.0; SPSS, Chicago, USA) to assess data according to the following aspects:

1. Trends: The variations over time, expressed by curves generated from Autoregressive Integrated Moving Average (ARIMA), were analyzed heuristically by observing the behavior of fitted value curves. The autocorrelation (ACF) and partial autocorrelation (PACF) plots evaluated the trends of time series for each country.

2. Seasonality: The impact of seasonality on the time series was observed using the generalized additive model (GAM) by detrending each curve over the period by its lag-1 difference, with subsequent application of different generalized linear models to examine the impact of monthly and quarterly seasonality on the time series.

3. Forecasting models: Twelve-month forecasts were built using ARIMA models based on the lowest values of the standardized Bayesian information criteria (normalized BIC) between curves without significant residual autocorrelation (Ljung-Box test).

4. COVID-19 pandemic impact: We analyzed the influence of social isolation associated with the COVID-19 outbreak on users’ interests in toothpastes. The quarantine start date was customized for each country ¹⁷ and the RSV values from 12 months before and after the outbreak were compared. Depending on normality and homogeneity (Shapiro-Wilk and Levene’s tests), the values were compared with Student’s t- test (AUS, BRA, CHL, GBR, JPN, MEX, RUS, and USA) or Mann-Whitney test (SAU and ZAF).

For all statistical analyses, values of p < 0.05 were considered significant.

RESULTS

Trends

Figure 1 presents the time series of the monthly variation. The heuristic analysis showed an increase in the interest related to toothpaste information in the 10 analyzed countries. Nevertheless, it is not possible to establish a clear trend from ACF and PACF analyses ( Figure 2 ). We detected a significant positive autocorrelation in CHL (lag 17), MEX (lag 12), RUS (lag 17), GBR (lag 6), SAU (lags 7, 8, and 23), ZAF (lag 6), and a positive partial autocorrelation in MEX (lag 7), RUS (lag 17), GBR (lags 6 and 11), SAU (lag 7), and ZAF (lag 13). However, we observed a significant negative autocorrelation in JPN (lag 4), MEX (lags 2, 3, and 9), RUS (lag 5), GBR (lag 9), SAU (lag 13), ZAF (lag 11), and a negative partial autocorrelation in JPN (lag 4), MEX (lags 2, 3, 9, and 16), RUS (lag 5), USA (lag 14), SAU (lag 13), and ZAF (lag 11).

Figure 1
Relative search volume (RSV) time series variation of toothpaste-related online searches and predictive charts for toothpaste-related interests among individuals from Australia (AUS), Chile (CHL), Japan (JPN), United Kingdom (GBR), United States (USA) – developed countries, and from Brazil (BRA), Mexico (MEX), Russia (RUS), Saudi Arabia (SAU), and South Africa (ZAF) – developing countries. The curves for the observed values (red lines), fit and forecast values (blue lines), and upper and lower bound of confidence intervals (violet lines) are depicted from January 2004 through December 2020. Note that RSV values presented after January 2020 (black line) represent 12-month predictive values.

Figure 2
Autocorrelation (ACF) and partial autocorrelation (PACF) plots for the monthly variation of RSV toothpaste values for Australia (AUS), Chile (CHL), Japan (JPN), United Kingdom (GBR), United States (USA) – developed countries, and for Brazil (BRA), Mexico (MEX), Russia (RUS), Saudi Arabia (SAU), and South Africa (ZAF) – developing countries.

Seasonality

The variation of the means of monthly detrended RSV values is represented on a heatmap ( Figure 3 ). According to GAM analysis, the data did not show a significant influence of monthly or quarterly seasonality on the interests of Google Search users. The chart shows occasional increases in search volume in January and February for MEX and January for GBR over time, thus indicating a preference of Mexicans and British people for searching for toothpaste at the start of the years.

Figure 3
Heatmap showing the variation of predictive generalized additive model (GAM) values for toothpaste-related online searches for Australia (AUS), Chile (CHL), Japan (JPN), United Kingdom (GBR), United States (USA) – developed countries, and for Brazil (BRA), Mexico (MEX), Russia (RUS), Saudi Arabia (SAU), and South Africa (ZAF) – developing countries. Seasonality was estimated by fitting a generalized additive model (GAM) to detrend the Google Trends data (lag-1 difference).

Forecasting models

Tables 1 and 2 show the statistics of 12-month forecasting models for toothpaste-related interests. The selected ARIMA models exhibited adequate normalized BIC (3.15–5.36), RMSE (4.65–14.27), and MAPE (6.82–30.86) parameters. The curves generated from this analysis allowed for the observation of trends in the data variation ( Figure 1 ). All countries showed a stable trend in the 12-month forecast.

Table 1
ARIMA model fit statistics for toothpaste.

Country, Model	R 2	Normalized BIC*	RMSE**	MAPE §	Ljung-box
					Statistics	p-value
Australia	0.24	4.06	7.31	15.61	22.34	0.99
ARIMA(0,1,1) (1,0,1)
Brazil	0.47	3.65	6.03	18.09	15.27	0.50
ARIMA(0,1,1)(0,1,1)
Chile	0.31	4.89	11.07	25.48	16.36	0.35
ARIMA(1,1,1)(1,0,0)
Japan	0.54	3.29	5.04	18.31	14.88	0.53
ARIMA(0,1,1)(0,1,1)
Mexico	0.37	4.91	11.31	23.39	62.23	< 0.01***
ARIMA(0,1,1)(0,1,1)
Russia	0.22	4.89	11.23	21.71	18.81	0.27
ARIMA(0,1,2)(0,0,0)
United Kingdom	0.29	3.15	4.65	9.38	27.69	0.02***
ARIMA(1,1,1)(0,0,0)
United States	0.15	3.51	5.58	6.82	14.79	0.54
ARIMA(1,1,1)(0,0,0)
Saudi Arabia	0.19	5.36	14.27	25.15	48.38	< 0.01***
ARIMA(0,1,4)(0,0,0)
South Africa	0.34	4.68	9.63	30.83	31.78	0.01***
ARIMA(1,0,11)(0,0,0)

• *Normalized Bayesian information criteria; **Root mean square error; ***significant at alpha = 5%

Table 2
Parameter estimation of ARIMA models for RSV toothpaste values in different countries.

Country/Parameter	Lag	Estimate	SE*	t	p-value**
Australia
Difference		1
MA**	Lag 1	0.73	0.49	15.02	< 0.001
AR***, Seasonal	Lag 1	0.86	0.94	9.16	< 0.001
MA‡, Seasonal	Lag 1	0.69	0.14	4.86	< 0.001
Brazil
Difference		1
MA***	Lag 1	0.80	0.46	17.44	< 0.001
Seasonal Difference		1
MA, Seasonal	Lag 1	0.68	0.65	10.54	< 0.001
Chile
AR****	Lag 1	0.23	0.82	2.86	0.005
Difference		1
MA***	Lag 1	0.89	0.39	23.26	< 0.001
AR § , Seasonal	Lag 1	0.36	0.68	5.37	< 0.001
Japan
Difference		1
MA***	Lag 1	0.74	0.05	14.95	< 0.001
Seasonal Difference		1
MA***, Seasonal	Lag 1	0.76	0.06	11.63	< 0.001
Mexico
Difference		1
MA***	Lag 1	0.78	0.69	10.88	< 0.001
Seasonal Difference		1
MA***, Seasonal	Lag 1	0.75	0.06	10.88	< 0.001
Russia
Difference		1
MA***	Lag 1	0.50	0.69	7.39	< 0.001
MA***	Lag 2	0.22	0.69	3.28	0.001
United Kingdom
Difference		1
MA***	Lag 1	0.72	0.05	14.41	< 0.001
AR, Seasonal	Lag 1	0.97	0.03	27.92	< 0.001
MA***, Seasonal	Lag 1	0.87	0.09	9.10	< 0.001
United States
Constant		0.01	0.01	2.52	0.012
AR****	Lag 1	0.49	0.09	5.36	< 0.001
Difference		1
MA***	Lag 1	0.87	0.05	16.19	< 0.001
Saudi Arabia
Difference		1
MA***	Lag 1	0.65	0.05	11.51	< 0.001
MA***	Lag 4	0.19	0.05	3.76	< 0.001
South Africa
Constant		20.91	7.40	2.82	0.005
AR****	Lag 1	0.98	0.02	46.97	< 0.001
MA***	Lag 1	0.87	0.04	18.05	< 0.001
MA***	Lag 5	0.29	0.07	4.02	< 0.001
MA***	Lag 6	-0.43	0.07	-6.05	< 0.001
MA***	Lag 11	0.09	0.04	2.04	0.042

• *Standard error; ** significant at alpha = 5%; ***Moving average component; ****Autoregressive component;

Main queries

The toothpaste-related searches were associated with specific brands or products, including toothpastes for tooth whitening and tooth sensitivity, baby or children’s toothpaste, recommendation for the best toothpaste, compounds such as charcoal, bicarbonate, fluoride, or fluoride-free products, homemade and natural toothpaste, abrasive, cooking salt, gingiva, gingivitis, mouth, periodontitis, teeth staining, and gum ( Table 3 ).

Table 3
Toothpaste-related queries and their respective RSV for each country. Terms with RSV = 0 were not considered.

AUS		BRA		CHL		JPN		MEX		RUS		GBR		USA		SAL		ZAF
Queries	RSV	Queries	RSV	Queries	RSV	Queries	RSV	Queries	RSV	Queries	RSV	Queries	RSV	Queries	RSV	Queries	RSV	Queries	RSV
toothpaste	100	toothpaste	100	toothpaste	100	toothpaste	100	toothpaste	100	toothpaste	100	toothpaste	100	toothpaste	100	Paste	100	toothpaste	100
Colgate	7	toothpaste	92	toothpaste	87	tooth	15	toothpaste	58	toothpastes	9	whitening toothpaste	9	best toothpaste	8	Toothpaste	60	colgate	12
colgate toothpaste	7	toothpaste	71	toothpaste	12	toothpaste whitening	14	toothpaste	46	toothpaste	6	best toothpaste	8	whitening toothpaste	7	Toothpaste	46	colgate toothpaste	11
whitening toothpaste	6	toothpaste	12	toothpaste	11	Whitening	14	toothpaste	8	Rocks	5	teeth	8	crest	7	toothpaste	30	whitening toothpaste	9
best toothpaste	5	Colgate	9	toothpaste	10	recommended toothpaste	8	Colgate	6	Rocks toothpaste	5	fluoride toothpaste	5	crest toothpaste	7	Best toothpaste	15	best toothpaste	6
tooth paste	4	toothpaste	6	Colgate	10	dentifrice	6	toothpaste	4	splat	4	fluoride	5	colgate	5	Toothpaste	4	toothpaste pimples	5
fluoride	4	colgate toothpaste	5	whitening toothpaste	5	Toothpaste white	6	Colgate toothpaste	4	whitening toothpaste	4	Colgate	5	charcoal	5	Crest paste	4	fluoride	5
fluoride toothpaste	4	how to make toothpaste	5	vitis toothpaste	5	Toothpaste ranking	5	toothpaste	3	children’s toothpaste	4	Colgate toothpaste	5	fluoride toothpaste	5	Whitening toothpaste	3	fluoride toothpaste	5
charcoal toothpaste	4	best toothpaste	5	ap24 toothpaste	4	White toothpaste	5	toothpaste	3	splat paste	4	toothpaste spots	4	fluoride	5	colgate	3	charcoal toothpaste	4
oral b	3	spine toothpaste	5	whitening toothpaste	4	White teeth	5	Water	3	splat toothpaste	4	charcoal toothpaste	3	colgate toothpaste	5	Crest toothpaste	3	sensodyne toothpaste	4
natural toothpaste	2	toothbrush	4	vitis toothpaste	3	toothbrush	4	toothpaste	3	acne toothpaste	2	teeth whitening	3	charcoal toothpaste	5	colgate toothpaste	2	sensodyne	4
oral b toothpaste	2	toothpaste	4	ap 24 toothpaste	2	Fluorine	4	soap	2	splat	2	best whitening toothpaste	3	tooth paste	4	Toothpaste for the face	2	ap24 toothpaste	3
sensodyne	2	glister	3	homemade toothpaste	2	Toothpaste Fluorine	4	how to make toothpaste	2	the best toothpaste	2	teeth whitening toothpaste	3	best whitening toothpaste	3	Sensodyne toothpaste	2	toothpaste on face	2
toothbrush	2	bicarbonate	3	homemade toothpaste ap 24 toothpaste	2	Commercial toothpaste	4	crest	2	buy toothpaste	2	oral b toothpaste	3	toothpaste acne	2	Toothpaste for children	2	aquafresh toothpaste	2
sensodyne toothpaste	2	toothpaste pregnancy test	3	toothpaste dispenser	2	Periodontal disease toothpaste	3	shampoo	2	splat toothpaste	2	oral b	3	baking soda toothpaste	2	Colgate toothpaste	2	ap 24 toothpaste	2
coles toothpaste	2	smile	3	no additional information		Periodontal disease	3	how to make toothpaste	2	toothpaste for children	2	tooth paste	3	sensodyne	2	Depurdent toothpaste	2	oral b toothpaste	1
teeth whitening	2	oral b	3	no additional information		Whiten teeth	3	homemade toothpaste	2	rocs toothpaste	2	sensodyne	2	natural toothpaste	2	Baby toothpaste	2	toothpaste brands	1
teeth whitening toothpaste	2	colgate toothpaste	3	no additional information		Toothpaste to whiten teeth	3	homemade toothpaste	2	fluoride-free toothpaste	2	toothbrush	2	sensodyne toothpaste	2	Baby paste	2	meridol toothpaste	1
toothpaste ingredients	2	best toothpaste	3	no additional information		Tooth whitening	3	colgate toothpaste	2	toothbrush	2	toothpaste on spots	2	kids toothpaste	2	sensodyne toothpaste	1	ap24 whitening toothpaste	1
how to make toothpaste	2	no additional information	3	no additional information		Children toothpaste	3	toothbrush	2	rocs toothpaste	2	sensodyne toothpaste	2	teeth whitening	2	Close-up toothpaste	1
kids toothpaste	2					Toothpaste to whiten teeth	3	best toothpaste	1	toothpaste president	2	sensitive toothpaste	2	teeth whitening toothpaste	2
best whitening toothpaste	2					Tooth whitening toothpaste	3	crest toothpaste	1	whitening toothpaste reviews	2	best toothpaste uk	2	how to make toothpaste	2
						Toothpaste turns white	3	Toothpaste	1	toothpaste for sensitive teeth	1	corsodyl	2	sensitive toothpaste	2
						Whiten teeth	3	what is toothpaste for	1	fluorine	1			toothpaste ingredients	2
						Abrasive	3	toothpaste for children	1	toothpaste slime	1

COVID-19 pandemic influences

Most countries did not demonstrate a significant difference in toothpaste interests before and after the COVID-19 outbreak , except for the increase in searches in GBR (p = 0.01) and ZAF (p = 0.049) ( Table 4 ).

Table 4
Comparison of the relative search volume (RSV) values between pre-pandemic and crosspandemic periods for all countries. They were compared through Student’s t test or Mann-Whitney test, depending on the normality and homogeneity of data.

Country	Student’s t test
	Average (RSV)		p-value
	Pre-pandemic	Cross-pandemic
Australia	80.16	81.12	0.798
Brazil	55.62	58.89	0.06
Chile	61.43	66.36	0.169
Japan	82.75	87.08	0.145
Mexico	86.17	86.71	0.854
Russia	60	58.32	0.396
United Kingdom	73.52	79.81	0.01*
United States	87.06	86.3	0.631
	Mann-Whitney test
	Sum of ranks (RSV)		p-value
	Pre-pandemic	Cross-pandemic
Saudi Arabia	127.5	172.5	0.193
South Africa	116	184	0.049*

• * significant at alpha = 5%.

Discussion

The heuristic analysis of the time series indicated an increase in the interest of internet users in toothpaste between January 2004 and December 2020. This increase may reflect the population’s growing autonomy regarding solving their own health problems. ¹⁸ , ¹⁹ Health care consumers seek autonomy regarding their health status and consequently invest more time in searching for information. ¹⁹ The Internet seems to be the most popular source of information, followed by books and advice from family and friends. ¹⁸ All countries showed a stable trend in the 12-month forecast of interests related to toothpaste after the COVID-19 outbreak , which may be explained by different factors, such as the relative deceleration of the increase in interest in toothpaste due to the heightened concerns related to the emergence of the new disease, the possible negligence of oral health self-care during social isolation, and also the previous incorporation of self-management of one’s own health into contemporary behavior, leading individuals to become more active in making decisions about their own health. ¹⁹ The use of friendly language, videos, and images enables the dissemination of information based on scientific studies in a reliable, adequate, and effective manner and contributes to the acquisition of new knowledge, in the eyes of the internet users and professionals. ²⁰ , ²¹ The motivation for searches is multifactorial and may be related to a concern about a specific disease, disease prevention, desire for a healthy lifestyle, curiosity, or even willingness to help others. ²²

Another possible reason for the increase in Internet searches about toothpastes may be related to industry marketing strategies. The growing awareness of the importance of oral health has led to an increase in purchases of dental healthcare products. ²³ Patients have limited knowledge about health care, which results in the use of the Internet as a source of information. ²⁴ Searches for an oral health problem may direct specific target audiences toward industry-maintained websites through algorithmic systems, ²⁵ which increases interest in and internet searches for specific brands. In fact, we detected an interest in specific brands from the main terms. Although these searches may provide oral health-related information to the general population, some patients may question or even replace professional guidance with their search results, ¹⁸ despite the quality of the information encountered on the Internet. It is also important to point out that searches for information regarding a particular purchase are analyzed from various perspectives. For instance, the consumers’ memory is, in many cases, the starting point of any search for information. ¹⁹

These results suggest an interest in natural products. Similarly, previous studies have detected interest in non-traditional therapies, alternative therapies, and home treatments for toothache on the Internet. ¹³ , ¹⁶ Natural products provide important contributions to pharmacotherapy and represent an opportunity for the pharmaceutical industry. There is growing consumer interest in natural and sustainable products. ¹³ , ¹⁶ , ²⁶ Recently, a boost in the sales of organic toothpastes has been observed. Consequently, the industry has turned its attention to this market, focusing its marketing strategies on campaigns that promote the concept of sustainability and environmental responsibility, such as reducing the consumption of plastic packaging, thus offering an opportunity to promote this segment. ²⁶ Most websites represent sales platforms. Thus, consumers may be misled by false claims about the efficacy of herbal products. ²⁷ These websites do not offer evidence-based information, serving as marketing tools for dissemination and sales, without proof of efficacy. As a result, information from these websites may pose a risk to the population’s oral health.

The present study showed there was a high interest in searches for the bleaching effects of activated charcoal, despite the lack of evidence to support its use for this purpose. Likewise, there is no evidence that charcoal-based toothpastes play a role in tooth remineralization or possess antimicrobial properties. ²⁸ On the contrary, there is some evidence that activated charcoal has negative impacts on the topography of dental enamel. ²⁹ Despite these facts, a recent study has identified 36 charcoal-based products, 72% of which had Instagram profiles with numerous followers and high engagement rates. These products are advertised as natural or organic, free of metals, and with bleaching properties. ³⁰ Moreover, the commercial appeal of celebrities in the promotion of these products associates them with an image of high quality. ³¹ Digital influencers inadvertently endorse such products on the Instagram platform arguing that these products are natural, as if this would guarantee the safety for use. The aim is to persuade their followers to purchase the so-called natural products, even if they lack scientific evidence of safety and efficacy. ³² The misleading fluoride information on Instagram is mostly commercial and is motivated by social, psychological, and/or financial interests. ³³

Another frequent search topic was related to toothpaste for children. Excessive toothpaste consumption has negative consequences, especially for children. Aggressive and misleading marketing strategies are used in selling fluoride toothpaste to children, while warnings about excessive consumption among youth are downplayed. ³⁴ These marketing strategies may be responsible for the increasing searches for toothpastes for children. Packaging is the main tool used by the industry to attract young consumers. ³⁴ When targeting adults, the marketing campaigns also focus on visual stimuli, considered the most direct and efficient marketing strategy to influence consumption habits. ³⁵

Easy access to the Internet is stimulating and may bring benefits. However, some internet users may perceive the information overload and the unreliability of the information as disadvantages. ¹⁸ , ²² Moreover, excessive information may lead to misinformation ³² and anxiety. ³⁶ The Internet empowers and engages people in knowing about health issues, alerting and noticing these issues, and the ability to manage and make healthy changes, ¹⁰ leading to shared decision-making between health professionals and patients. ³⁷

It should be, however, mentioned that health information published on the Internet does not provide the users with credible and reliable medical advice. ¹⁸ The health information available online is mostly incomplete, outdated, unreliable, and unreasonable from the scientific point of view. ²² Surveillance of digital activity aims to combat scientific misinformation by minimizing the spread of fake news/misinformation/disinformation and promoting the development and implementation of public health information and awareness campaigns. ³⁷

It was not possible to detect a significant increase in interest in toothpaste-related topics during the COVID-19 outbreak in most of the analyzed countries (AUS, BRA, CHL, JPN, SAU, MEX, RUS, and USA). This finding conflicts with those related to searches about toothache or toothache treatment on Google ³⁸ and Twitter. ³⁹ One possible reason is that during a pandemic, characterized by infodemic and excessive information about a disease outbreak, ⁴⁰ a non-urgent issue can be neglected.

The design of this study has some limitations and the findings need to be interpreted with caution. These data refer exclusively to the activity and behavior of users of one web platform (Google Search), without considering information from other search engine tools. Additionally, anonymity makes it impossible to detect characteristics of sex, age, sociodemographic aspects, and educational level of the users. Furthermore, this approach does not rule out the possibility of duplicate searches performed by the same person on two or more devices, and the outcomes may be overestimated. Finally, although the behavior of Internet users suggests a growing interest in oral health self-care surveys, it is not possible to confirm the implementation of corrective measures. The analyses were performed based on a standardized metric. Thus, this approach does not allow direct comparisons between research volumes in different countries. Although promising, the collection and interpretation of a large amount of computational data based on Internet activity do not replace traditional epidemiological methods. However, the anonymous and periodic collection of near real-time data in several distinct countries may contribute to a greater understanding of behavioral data. As such, this information may enable the implementation of specific public oral health policies and oral-care communications based on the population’s needs. Along these lines, information monitoring and improvements in oral health literacy may contribute to the reduction of currently existing social and economic barriers.

Conclusion

In support of our hypothesis, the interest of Google Search users in information about toothpaste increased in all of the 10 analyzed countries. However, these trends were not usually influenced by the COVID-19 outbreak. Understanding the interest in health information underscores the importance of further analysis of community concerns and needs, by emphasizing the need for investigations into digital activity and the promotion of health literacy and oral hygiene education policies.

Acknowledgements

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (Capes) – Finance Code 001. In addition, this study was financed in part by grant 2019/27242-0, São Paulo Research Foundation (Fapesp).

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Publication Dates

• Publication in this collection
  15 Dec 2023
• Date of issue
  2023

History

• Received
  5 Apr 2023
• Reviewed
  24 July 2023
• Accepted
  31 Aug 2023