Community interventions and strategies for caries control in Latin American and Caribbean countries

Dental caries remains highly prevalent in Latin American and Caribbean countries (LACC). However, this disease can be controlled through interventions that implement evidence-based strategies in an affordable manner and that target all population groups instead of the most affluent only. Therefore, the aim of this report was to summarize the main scientifically documented community interventions and strategies based on restriction of sugars consumption, use of fluoride, and the use of occlusal sealants for caries control in LACC. A critical literature review was carried out in a systematic manner that included defined search strategies, independent review of the identified publications, and compilation of results in this report. Three systematic searches were conducted using the PubMed, LILACS, and SciELO databases to identify studies related to community interventions and strategies for caries control in LACC. Of the 37 publications identified, twenty-six focused on fluoride use, eight on occlusal sealant use, and three on the restriction of sugar consumption. Documented community interventions for sugars restriction were scarce in the region and were based on food supplementation, sugar replacement, and education. Thus, local and/or national policies should prioritize investment in upstream, coherent, and integrated population-wide policies such as taxes on sugary drinks and stronger regulation of advertising and promotion of sugary foods and drinks mainly targeting children. The main fluoride-based strategies used drinking water, refined domestic salt, cow milk, toothpaste and, to a lesser extent, mouth-rinses, acidulated phosphate fluoride (APF) gels, and varnishes to deliver fluoride to the population. Evidence of fluoride use was seen in Argentina, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, Guatemala, Haiti, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Uruguay, and Venezuela. Studies reporting the use of occlusal sealants were mainly located in Brazil, Chile, Colombia, Costa Rica, Peru, Mexico, and Venezuela. Community interventions restricting sugar consumption should be implemented at the individual level and through public policies. The use of fluoride must be monitored at the local, regional, and national levels so as to achieve maximum anti-caries effect while also minimizing the risk of dental fluorosis. Moreover, fluoridated water and salt programs, used as a mutually exclusive community level strategy for caries control, should expand their benefits to reach non-covered areas of the LACC Declaration of Interests: The authors certify that they have no commercial or associative interest that represents a conflict of interest in connection with the manuscript. Corresponding Author: Antônio Pedro Ricomini Filho E-mail: ricomini@unicamp.br https://doi.org/10.1590/1807-3107bor-2021.vol35.0054 Submitted: March 10, 2021 Accepted for publication: March 11, 2021 Last revision: March 16, 2021 1 Braz. Oral Res. 2021;35(suppl):e054 Community interventions and strategies for caries control in Latin American and Caribbean countries


Introduction
Despite rapid advances in the understanding of dental caries and strategies to control it, 1 the disease continues to be highly prevalent in many countries, particularly in Latin American and Caribbean countries (LACC). 2,3 Dental caries occurs due to frequent exposure of the dental biofilm to sugars, highlighting the key role that dietary carbohydrates play in disease onset and progression. 4,5 These sugars are fermented by bacteria present in the biofilm, producing acids that lead to tooth (enamel/dentine) demineralization via a physicochemical process. 6 Consequently, teeth that are exposed to periods of demineralization more frequently than remineralization, which is a naturally occurring process, exhibit increased loss of tooth minerals and subsequent development of caries lesions. 4 Sugars play a pivotal role in the development of dental caries as without fermentable carbohydrates, the bacteria are unable to produce acids necessary for tooth demineralization. 4 This suggests that the disease can be controlled, and various community and population-based intervention strategies have been applied to interfere with the de-remineralization process contributing to reduce mineral loss. Methods to control caries based on the restriction of sugar consumption, use of fluoride, and placement of occlusal sealants have been implemented. The strategy based on restriction of sugar consumption aims not only to reduce the consumption, but also focuses on the use of alternative sweetening compounds that are not fermented by bacteria as well as substances with putative anti-caries activity.
Another well-established strategy for caries control involves the use of fluoride which interfere with the physicochemical process of tooth (enamel/dentine) mineral dissolution. 7 The presence of fluoride in the oral cavity not only reduces demineralization but also enhances tooth re-mineralization. 8 Intervention strategies typically rely on different approaches to deliver fluoride into the oral cavity, and these can be classified into different categories based on their level of action, as follows: community level (water, salt, and milk fluoridation), individual level (fluoride dentifrices and mouthrinses), and clinical interventions (gel, varnish, foam). From the public health perspective, individual actions that are not isolated but are a part of a general systematic effort aiming to produce an effect in the population are considered to be actions at the community level. These include school programs incorporating the use of fluoridated mouthwashes and supervised tooth-brushing with fluoridated toothpastes. Irrespective of the approach employed, the common goal of all of these interventions is to maintain a certain concentration of fluoride in the oral cavity so as to enhance its preventive and therapeutic effects.
When used within the framework of a community program, the placement of dental sealants to cover pits and fissures on the occlusal surfaces of teeth has also been found to be effective in controlling caries, particularly in high-risk individuals. 9 The fissured occlusal surfaces of first permanent molars as well as their lower buccal and upper lingual pits are highly susceptible to caries lesions, and the use of occlusal sealants in these areas not only prevents the onset of caries lesions by interfering with bacterial adhesion and growth but also acts as a physical barrier and helps to seal dental irregularities, thus protecting the tooth surfaces from interaction with bacterial acids responsible for demineralization. There are a wide while also simultaneously providing adequate surveillance of the fluoride concentration delivered to the population. Regulating the concentration of soluble fluoride (for anti-caries effect) in dentifrice formulations is also necessary in order to provide the population with an effective strategy for disease control. Targeting culturally appropriate, economically sustainable caries control interventions to rural populations and native ethnic groups such as indigenous people, quilombolas (African-origin), and riverside Amazonian people remains a crucial challenge.
range of commercially available occlusal sealant materials, the most common of which are resins and glass-ionomer based cements.
Although such community interventions and strategies have been adopted for caries control, compiled data on their use in Latin American and Caribbean countries (LACC) or summarized evidence on their effectiveness are scarce. Further exploration of the extent of implementation of these measures in LACC will not only help develop a better understanding of the actual scenario in these countries, but also guide public health policies and decision-making with regard to the appropriateness of community and individual-level interventions for caries control within the context of these regions. Therefore, the aim of this report was to summarize the main scientifically documented community interventions and strategies based on restriction of sugar consumption, use of fluoride, and the use of occlusal sealants for caries control in LACC.

Methodology
Search method and inclusion/exclusion criteria Three separate systematic searches were carried out to identify studies related to community interventions and strategies aiming to control caries in LACC by a) restricting sugar consumption, b) using fluoride, and c) placement of dental sealants. Prior to this, the researchers were calibrated by carrying out a pilot search aiming to identify studies focusing on restriction of sugar exposure and use of fluoride using the database, PubMed.
The These pilot searches recovered 239 studies on sugars restriction and 561 studies on fluoride use via community interventions and strategies for caries control. The Rayyan web-tool was used during the selection/exclusion process, 10 and a total of 100 studies from each topic were selected to be independently evaluated by two reviewers (sugars restriction: B.A.C. and R.A.G.; fluoride use: A.P.R.F. and P.F.). The titles and abstracts were screened for eligibility, and the selection criteria were established during this stage. Studies reporting strategies based on the restriction of sugar consumption or fluoride use for caries control in at least one Latin American and Caribbean country were included, while those that were of the wrong publication type, did not address the research question, or did not have an abstract available were excluded.
Thereafter, final searches for studies on interventions restricting sugar consumption and fluoride (June 17, 2020) use were carried out on the PubMed, LILACS, and SciELO databases using the same keywords with minor modifications relevant to each database. A third systematic search to identify strategies based on the use of pit and fissure sealants for caries control (July 28, 2020) was also carried out on PubMed using the following search string: (Sealants The studies recovered from these searches were then uploaded in to the Rayyan web-tool and organized into the three relevant categories. Duplicated studies were identified and removed, and each topic was independently evaluated by two reviewers (sugar restriction: B.A.C. and R.A.G.; fluoride use: A.P.R.F. and P.F.; and dental sealant: A.P.R.F. and P.F.). The titles and abstracts were screened for eligibility. Studies focusing on the restriction of sugar consumption were categorized based on the intervention strategy, as follows: education, sugar replacement, and food supplementation. Studies focusing on fluoride use were categorized based on the method of delivery used, as follows: water, salt, milk, dentifrice, acidulated phosphate fluoride (APF) gel, mouth-rinse, and varnish. Lastly, studies focusing on the use of dental sealants were evaluated as a single topic without further categorization. The studies within the three topics were also organized according to LACC, and the current report is structured to provide data on at least one representative study from each LACC identified as using restriction of sugar consumption, fluoride use, or dental sealant as a strategy for caries control. The search strategy and study selection methods have been summarized in Figure

Results
The identified studies focusing on interventions using restriction of sugar consumption, fluoride use, or dental sealant as a strategy for caries control in LACC are shown in Tables 1, 2 and 3, respectively. The search method ( Figure) yielded the highest number of studies focusing on interventions based on fluoride use (Table 2), followed by a smaller number of studies focusing on restriction of sugar consumption ( Table 1) and use of occlusal sealants ( Table 3) for caries control.
Several LACC such as Belize, Brazil, Chile, Colombia, Puerto Rico, and Venezuela adopted interventions based on restricted exposure to sugar via food supplementation, sugar replacement, and education. Two studies (one of which was a pilot study) reported interventions aimed at food supplementation using probiotics, while another focused on a school-based intervention 11 that showed a significant reduction in caries upon administration of milk twice per day among preschool children. The most common methods of sugar replacement for caries control involved the use of chewing gums (reported by 6 out of 7 relevant studies) and sorbitol mints (reported by one study), and the majority of studies reported adopting a polyol-based approach to replacing sucrose. Four of the screened publications reported findings from a single study and its follow-up carried out in Belize, 12 and their results suggested

Food supplementation
Aim: To determine the effects of probiotic-milk supplementation on caries incidence in preschool children.
Methodology: Triple-blinded, placebo-controlled randomized trial; 261 children aged 2 -3 years old from 16 nursery schools in Santiago, Chile were included. The nursery schools were allocated into two arms, as follows: 1) Intervention arm: 150 mL of milk supplemented with Lactobacillus rhamnosus SP1 (10 7 CFU/mL) administered on weekdays for 10 months, and 2) Control arm: non-supplemented cow milk administered. Follow-up lasted 10 months with a clinical exam at the end. Dropout rate: 21%.

Sugar replacement
Aim: To determine the cariogenicity of sucrose-based chewing gums in children.
Outcome: Modified WHO procedure for identification of non-cavitated and cavitated carious lesions.
Results: Sucrose gums increased the caries scores (RR 1.20; CI 0.96 -1.49; p = 0.1128), while sorbitol gums decreased the caries scores (RR 0.74; CI 0.6 -0.92; p = 0.0074). Although all four variants of Xylitol gums were effective in decreasing caries rates, the most effective were those containing 100% Xylitol (RR 0.27; CI 0.20 -0.36; p = 0.0001). The Xylitol/Sorbitol combination decreased caries incidence compared to the control group, but was less effective than the Xylitol only group.

Brazil
Feldens et al,

13 Education
Aim: To determine the effectiveness of home visits to educate mothers on the effects of breast feeding and weaning on early childhood caries (ECC).
Methodology: Randomized community trial including 500 mother-child pairs (intervention group: 200, control group: 300). Intervention: Advice 10 days after the child's birth, repeated monthly up to 6 months, and then again at 8, 10, and 12 months.
Results: Intervention group: 10.2% with ECC; Control group: 18.3% with ECC. The intervention group had 48% lower odds of developing caries (OR 0.52, CI 0.27 -0.97) compared to the control group. Mean DS was lower for the intervention group (0.37) than the control group (0.63). The intervention group also exhibited longer duration of exclusive breast feeding, later introduction of sugar to the diet, and lower probability of eating sugary foods. Water 1975 -Law proposing fluoridation or de-fluoridation of drinking water to achieve optimal fluoride concentration passed.
Samples of water (2008 -2012) were collected from 190 localities in 17 departments in the province of Tucumán, Argentina.
The results showed that 1% of the population consumed water with optimal fluoride concentration (0.7-1.0 ppm F), 94% consumed water with fluoride concentrations below the recommended limits, and 5% were exposed to fluoride concentrations above the optimal limit The sanitation strategies adopted in larger cities serve as a basis for smaller demographic municipalities in the same regions by the influence they have. Water and milk Water fluoridation was first implemented in some cities in 1953, and was then expanded to other cities in the country by 1984.
In rural areas with no access to tap water, fluoride was provided though a Fluoridated School Feeding Program using milk.
Currently, 83 % of the urban population, representing 72% of the total population of Chile, has access to fluoridated drinking water.
Brazil Cury et al., 2004 18 Water, dentifrices, APF, and mouthrinses 1953 -Water fluoridation introduced; 1975 -federal law advising water fluoridation in all cities having water treatment systems passed.
1989 -The most popular commercially available Brazilian dentifrice was fluoridated.
1990s -Spread of preventive programs (tooth-brushing at schools with fluoride dentifrices, weekly fluoride rinsing, and APF application).
Water fluoridation, expansion of preventive programs at schools, and the widespread use of fluoride dentifrices are consistently linked to the decline in caries incidence observed in Brazil (1986Brazil ( -2003.
Haiti Bedos and Brodeur, 2000 19 Water and sealant Although caries prevention methods such as the application of occlusal sealants and the use of fluoridated water have been mentioned as desirable, the associated costs make implementation difficult for a developing country. Five states excluded due to the presence of natural fluoride in higher than optimal concentration in the water.
Partially incorporated in eleven states due to the presence of natural fluoride in concentrations > 0.7 ppm in the water supply of some municipalities.
Concerns about dental fluorosis. Of these, only two brands presented optimal fluoride concentration, as required by the legislation. Among the other brands, 2 were not fluoridated and five had fluoride concentrations below the mandated range.

García
Surveillance systems for the salt fluoridation program should be improved.  Two population-based oral health surveys of 12-year-old school children exposed to a) artificially fluoridated water in Porto Alegre, South Brazil, and b) artificially fluoridated salt in Montevideo, Uruguay.
"Salt fluoridation is recommended by the WHO as an alternative method when water fluoridation might be unavailable for technical, financial, or sociocultural reasons." Furthermore, the salt fluoridation program in Uruguay is limited to salt for domestic use only, with no coverage of public and private canteens, restaurants, and bakeries as recommended by the WHO.
In Porto Alegre, most of the water for human consumption, available through the public water supply system or as commercially available bottles, is fluoridated.

Cuba
García Salt, water, and milk The use of fluoride as a public health strategy may be hindered by the prevalence and severity of dental fluorosis. This is further complicated by a general lack of knowledge regarding dental fluorosis (even by health professionals) and the absence of monitoring to ensure appropriate fluoride use.
This is a common concern in most Latin American countries with salt and water fluoridation programs; however, the occurrence of high concentrations of fluoride in the water in some regions may result in dental fluorosis, as seen in some parts of Mexico.

Brazil
Conde et al., 2003 31 Dentifrice Five dentifrices most commonly used in Brazil were evaluated (1000 to 1500 ppm F).
All of the dentifrices were manufactured in Brazil.
MFP was present in 100% of the samples analyzed.
All dentifrices contained a total soluble fluoride (TSF) concentration greater than 1000 ppm F to provide an anti-caries effect.
Chile Fernández et al., 2017 32 Thirty dentifrices commercially available in the three main chain drugstores in Chile were evaluated.
Among dentifrices targeting children, only 25% contained > 1000 ppm F. A total of 42% of dentifrices had low fluoride concentrations (422 to 475 ppm F) with MFP and CaCO 3 as abrasives, thus lowering the TSF further.

Peru
Chavez et al., 2019 33 Twenty-three dentifrices, of which four did not have fluoride and 19 had fluoride in concentrations ranging from 452 to 1450 ppm F, targeting children were evaluated (Lima, Peru).
All of the dentifrices were manufactured in Ecuador, Peru, USA, China, Mexico, Brazil, and Spain.
NaF was present in 70% of the samples analyzed and MFP was present in 30%.
Most dentifrices exhibited total fluoride (TF) concentration equal to that mentioned on the label. However, one dentifrice exhibited a concentration of 515.1 ppm F, despite advertising 1450 ppm on the packaging.
The majority of children's dentifrices were fluoridated, although only 53% contained a TSF concentration greater than 1000 ppm F (necessary for anti-caries effect).
Uruguay Loureiro et al., 2017 34 Six commercial brands of children's dentifrices available in Uruguay were tested (500 to 1100 ppm F). The dentifrices were manufactured in Uruguay, Mexico, and Brazil. NaF was present in 83% of the samples analyzed and MFP was present in 17%. Two dentifrices contained NaF with CaCO 3 as abrasive (incompatible, > 50% fluoride insoluble). One dentifrice was formulated with MFP and CaCO3 as abrasive (compatible). Three dentifrices contained NaF and Silica, resulting in TSF concentration similar to TF. Only 33% contained a TSF concentration greater than 1000 ppm F (necessary for anti-caries effect). Brazil Iwakura and Morita, 2004 35 Mouth-rinse 1970s -The role of fluoride mouth-rinse programs in caries control strategies was re-evaluated.
In Brazil, the application of 0.2% sodium fluoride mouth-rinse has been one of the most commonly used methods of preventing caries after the fluoridation of public water supply.
In *Although the key focus of the publication is exposure to fluoride, we carried out a critical review of strategies for the use of fluoride in LACCs.
Continuation that replacement of sucrose in chewing gums with Xylitol was the most effective method of reducing caries in school children, followed by sorbitol or a combination of both. Importantly, favorable outcomes were seen to be more pronounced when the comparator group was "no gum control." These studies were mostly conducted by researchers based in the United States and Finland. All five studies that reported adopting educational strategies were carried out in Brazil, with 3 of them reporting on the same intervention. The educational approaches mostly involved parental counseling on feeding practices during early childhood through community interventions, 13 and the majority reported significant reduction in caries rates. Some of the studies focusing on interventions restricting sugar exposure did not measure caries outcomes and used proxy variables instead. Moreover, none of the studies investigated the effects of these interventions in adults or older adult populations in the region.
Interventions based on fluoride use for caries control were mainly adopted in the following LACC: Argentina, Belize, Bolivia, Brazil, Chile, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, Children (aged 6-7 years) from public primary schools in a low socioeconomic area of Paranoá city, Brasilia, Brazil, participated in this study.
A 3-year cost-effectiveness analysis was carried out to compare the ability of composite resins, atraumatic restorative treatment (ART) using high-viscosity glass-ionomer cement sealants, and supervised tooth-brushing to prevent cavitated dentine carious lesions in high risk first permanent molars.
The results showed that supervised tooth-brushing had lower costs and higher savings per cavitated dentine carious lesion prevented compared to composite resin and ART sealants. The analysis model showed that the universal application of resin sealants as part of school-based sealant programs in Chile would be a cost-effective measure in populations where the prevalence of caries in first permanent molars was high.
Public policies should include the application of sealants in children from low-income families where caries risk is high. Costa Rican children aged 12 years and going to public or private schools were examined for the presence of at least one sealant on one of their permanent teeth.
The prevalence of pit and fissure sealants was 60% in the central region of the country, and less than 30% in other areas of the country. The dentine carious lesion failure rates for the use of ART sealants in primary and permanent teeth over the 2-year period were 0% and 2.5%, respectively.

Soto-Rojas et al., 2012 45
Study developed as an international service-learning program targeting small rural communities in Calnali, Hidalgo, Mexico.
Resin-based sealants placed in children (aged 6-15 years) living in a rural setting.
The high prevalence of caries in this rural population suggests that there is still a great need for comprehensive dental public health programs.

Peru
Pachas Barrionuevo et al., 2009 46 The study assessed the survival rates of ART sealants applied on the occlusal surfaces of permanent molars and premolars in schoolchildren (aged 8-13 years) from a public school in Lima after a 2 year intervention follow-up.
The use of the ART technique has shown encouraging results for the prevention of dental caries. It can be implemented in populations living in rural and marginal urban areas.  (Table 2). Of these, the majority of the publications reported on fluoride use in Brazil (7 studies) and Chile (4 studies), while the remaining countries all had at least one study reporting fluoride-based interventions.
The main f luoride-based st rateg ies used drinking water, refined domestic salt, cow milk, and toothpastes, while community-based interventions utilizing mouth-rinses, gels, and varnishes were documented to a lesser extent (Table 2). Although our searches identified many publications examining soluble fluoride content in commercial dentifrices used by the population, this review only included the four studies that were carried out in LACC (Brazil, Chile, Peru, and Uruguay). The remaining relevant studies included in this report focused on the use of fluoride varnishes in Brazil, 36 Chile, 37 Dominican Republic, 38 and El Salvador, 39 and on the use of a combination of fluoride mouth-rinses and APF gels in Brazil 18,35 and Peru 30 . Some publications were more comprehensive and documented several strategies for fluoride use within the same country, such as in Chile, 17 Cuba, 16 Brazil, 18 Colombia, 29 Haiti, 19 and Peru, 30 or reported one or more strategies adopted in several LACC. 20,26,27 The remaining studies reported one specific strategy adopted in a single Latin American and Caribbean country.
Interventions based on the use of occlusal sealants for caries control (Table 3) were adopted in Costa Rica 43 and Mexico. 44,45 The remaining studies mainly evaluated the use of occlusal sealants in local settings, focusing mainly on children at high risk of developing caries and belonging to lower socioeconomic strata or rural areas of Brazil, 40 Chile, 41 Colombia, 42 Peru, 46 and Venezuela. 47

Discussion
This report summarized the main scientifically documented community interventions and strategies based on restricted exposure to sugars, use of fluoride, and use of occlusal sealants for caries control in Latin American and Caribbean countries (LACC). The majority of the evidence focused on strategies based on fluoride use, and the results of this review are important in the context of the changes in our understanding of dental caries and possible ways to control it, defining new perspectives to control the disease in LACC. 48 Dental caries, previously considered to be a transmittable infectious disease, has now been clearly understood as a non-communicable disease that can be controlled. 1 This paradigm shift is also reflected in the strategies employed by LACC to control the disease.
Although fluoride has been considered as an effective agent for the control of dental caries since the 1930s, the role of exposure to sugars in caries development was only re-emphasized recently. While biofilms are ubiquitous on teeth and are constantly forming, bacteria can only produce acids that are responsible for tooth demineralization and formation of caries upon frequent exposure to sugars. 49 Therefore, effective caries control strategies must include components targeting sugar consumption. It is also essential to differentiate lesion management from disease control, as limiting lesion progression through a restorative approach will only act at the tooth level. Disease control measures, however, must target behavioral, dietary, and hygiene factors for a more holistic approach. Among the dietary carbohydrates, sucrose favors the faster growth of biofilms and changes in their matrix that contribute to higher acidogenicity which, in turn, leads to increased tooth demineralization. 4 However, intervention strategies based on the restriction of sugar exposure are still scarce in LACC (Table 1), and the three main approaches adopted so far are education, sugar replacement, and food supplementation. In 2015, WHO released a guideline with recommendations on the intake of free sugar to reduce the risk of non-communicable diseases such as obesity, diabetes, and dental caries in adults and children. 50 Products containing high concentrations of sugar and poor nutritional content usually tend to be cheaper and are, therefore, more frequently consumed by the population, particularly low-income families. However, the limited number of studies reporting interventions based on restricting sugar exposure in LACC has made it difficult to understand the impact of these interventions in these countries, taking into consideration contextual factors.
Further research in the field of educational programs intended to reduce the burden of untreated caries as well as studies examining the impact of these interventions in older populations are necessary.
Even though food supplementation with probiotics or putative anti-caries nutrients 51 appears to be an attractive approach for caries control, there is limited evidence on their efficacy. Taking into consideration the difficulty of effectively controlling sugar intake in the Latin American and Caribbean region, reducing cariogenicity within a cariogenic background while taking sociocultural factors into consideration may represent an opportunity for caries control. Sugar replacement using alternatives such as chewing gums containing Xylitol appear to have more grounds for appropriate caries control, at least in children. 12 The majority of studies exploring this were conducted several years ago in Belize by the same group of researchers who reported long-lasting effects of administration of polyol gums five times per day for more than 3 years. However, a recent systematic review conducted by Riley et al. 52 reported insufficient evidence on the effectiveness of xylitol-containing products in controlling caries, based on the low to very low-quality of evidence available on it.
Finally, education seems to be the most rational approach to controlling caries. Most programs reported in LACC have achieved caries reduction in young children through the provision of home or school-based education. 13 Additionally, educating parents on correct feeding practices from early life also proved to be advantageous as it prevented the onset of diseases and ensured healthy behavioral and dietary practices that would likely persist throughout the life course. Some of the interventions reported also included provision of oral hygiene education, including reinforcement of tooth-brushing habits to mechanically remove the biofilm present on teeth. Although tooth-brushing alone without the use of fluoride dentifrices have limited effect on caries control, 53 daily disruption of the biofilm was seen as a desirable practice.
Although interventions at the individual level by dental professionals are important for maintenance of good oral health, restriction of exposure to sugar requires intercession at the public policy level and there have been some recent developments in this area in LACC. For example, policies proposing food labeling were recently approved in Chile, México and Ecuador, and initial assessment of their effects suggest positive outcomes. 54 Chile first implemented a food labeling program, wherein high-sugar foods (as well as saturated fats, calories, and salt) were labeled with a black stop sign, 55 and it has since been reported that the purchase of such products decreased by 23.7%. This was significantly higher than the effects of a sugar tax, a measure adopted in various countries around the world as well as in the LACC region (including Chile and Mexico). The findings of this review highlight the importance of incorporating measures restricting sugar exposure in every caries preventive program and also reinforce the need for further research in this area. As individualistic, clinical, and educational preventive approaches fail to tackle the underlying cause of disease, researchers have postulated that priority should be given to investment in upstream, coherent, and integrated population-wide policies such as taxes on sugary drinks and stronger regulation of advertising and promotion of sugary foods and drinks targeting children. 56 Of the various fluoride delivery strategies available, the use of fluoridated water or salt were found to be the most popular options in LACC as both approaches allowed intervention at a wider community level. Several countries such as Argentina, Brazil, Colombia, Cuba, Ecuador, Jamaica, Panama, Peru, and Chile authorized fluoridation programs and began implementation in water treatment plants of certain cities; however, of these, only Brazil and Chile managed to achieve extensive coverage (Table 2). This was mainly because many countries chose to adopt salt fluoridation programs instead, based on PAHO's Regional Oral Health Plan, 57 although the extent of coverage has not been documented. Moreover, some studies have shown that salt samples did not meet the required specifications 24,25,29 and were also sold in areas with drinking water already containing optimal natural levels of fluoride for caries prevention, 21 leading to increased incidence of dental fluorosis. 23 A greater understanding of the natural occurrence of fluoride in water and the difficulties associated with limiting the commercialization of fluoride salt in these areas led to concerns regarding increased risk of dental fluorosis and the emergence of timely surveillance systems in many countries. 14,22,29,30 Preventing multiple sources of fluoridation can only be achieved through policy decisions that approve regulatory mechanisms maintained by governmental institutions. Dental fluorosis is a late marker of excessive fluoride exposure, making implementation of surveillance systems focusing on the intake and quality of drinking water and other sources of fluoride necessary. Such systems must take advantage of the information and communication technologies available in order to expand their use at various levels of society. In this context, it is possible that the adoption of digital health technologies can play an important role in achieving some of the Sustainable Development Goals, 15 one of which aims to achieve universal and equitable access to safe drinking water for all by 2030.
The concentration of fluoride in water represents a basic parameter for the assessment of its quality and safety as sub-optimal levels may increase the risk of dental caries while above-optimal levels may lead to dental fluorosis. 58 Although some LACC have clear policies on the use of fluoride, there are still many that do not, suggesting the need for prioritization of investigations into the natural occurrence of fluoride in water and the development of measures necessary to achieve levels optimal for caries prevention. 9 Where this is not possible, population-wide strategies such as fluoridated salt or milk should be considered as the possibility of two or more simultaneous sources of fluoride intake can then be eliminated or reduced. 29 Water and salt fluoridation programs have contributed significantly to the decline in dental caries observed in LACC. However, for several reasons beyond the scope of this article, these strategies are often not homogeneously implemented in all regions of the countries and, therefore, sometimes do not reach the populations most vulnerable to the development of caries. Greater professional advocacy and involvement of other sectors representative of the populations are necessary in order to drive governmental actions necessary for the expansion of these programs where appropriate and re-assessment of public policies where they have been implemented already. Remote and rural areas are seldom favored by these programs, and urgent development and implementation of customized interventions are necessary. The use of fluoridated milk as a community level intervention has been reported in some rural areas of Chile. 17 However, targeting culturally appropriate, economically sustainable caries control interventions to rural populations and native ethnic groups such as indigenous people (> 45 million and over 800 ethnic groups), quilombolas (African-origin), and riverside Amazonian people remains a crucial challenge.
Fluoride dentifrices are another globally popular strategy for caries control 59 as they represent the most rational individual level approach that promotes biofilm removal during tooth-brushing while simultaneously delivering fluoride into the oral cavity. The mechanical removal of dental biofilm by daily tooth-brushing not only controls the development of dental caries but also helps in the prevention of periodontal diseases. A single episode of manual tooth-brushing may reduce dental biofilm up to 42%. 60 It is also noteworthy that complete removal of the biofilm is challenging, especially in areas of the mouth that are difficult to access while brushing and, therefore, are more susceptible to disease. Therefore, daily release of fluoride into the oral cavity via dentifrice formulations represents a necessary strategy for caries control and should be encouraged regardless of the presence of water or salt fluoridation programs. Moreover, additives have been incorporated into fluoride toothpastes in an attempt to improve its anticaries effect. These substances include arginine, baking soda, calcium glycerophosphate, CPP-ACP, CPP-ACPF, and sodium hexametaphosphate. Promising findings have been reported for some of them. Hence, there is good reason to believe that new technologies should be investigated further as they have the potential to complement and enhance the effects of fluoride and reach the status of effective innovations in caries prevention.
A common characteristic of most commercially available dentifrices in LACC is the use of calcium carbonate (CaCO 3 ) as abrasive (Table 2). This is mainly because it is cheaper than silica and is, therefore, more widely used, particularly in low-income families , being an affordable toothpaste formulation. 61 However, CaCO 3 abrasive is only compatible with monofluorlophosphate (MFP) as chemically soluble fluoride tend to remain stable in its presence. The ion fluoride present in sodium fluoride (NaF), stannous fluoride (SnF 2 ), or amine fluoride (AmF) react with the calcium present in CaCO 3 abrasive, dramatically, decreasing the soluble fluoride concentration and resultant anti-caries effect. Despite this interaction is a well-known fact, NaF was detected in several CaCO 3 -based dentifrice formulations sold in Chile 32 and Uruguay, 34 raising questions regarding the amount of soluble fluoride present in the formulations. In addition to an increase in the amount of non-fluoridated dentifrices available in the market, there are also a wide range of formulations with low concentrations of fluoride which certainly affect their potential to control caries. Consequently, proper legislations 62 that regulate the amount of soluble fluoride present in dentifrices targeting adults as well as children so as to achieve optimal levels for caries control are necessary in LACC. Evidence shows that use of dentifrices containing at least 1000 ppm of fluoride twice per day is highly effective in caries prevention, 63,64,65 emphasizing a need to encourage their use in the population.
Other less frequently reported approaches of fluoride delivery in LACC include mouth-rinses, APF gels, and varnishes. Fluoride mouth-rinses have been adopted as an individual level, school-based intervention in Brazil 18,35 and Peru, 30 although it is likely that they were also implemented in other LACC. The preventive effect of mouth-rinses has been reviewed as other fluoride sources (e.g., water, salt, toothpaste) may be present, contributing to caries control. 65 APF gels and fluoride varnishes represent a professional approach to fluoride delivery, and studies reporting their use in LACC did so in the context of specific populations only and not in a clinical environment. School-based programs incorporating APF gel application as a complementary approach for mouth-rinses have been reported in Brazil 18 and Peru, 30 while the use of fluoride varnishes as a desirable preventive public health measure targeting high-caries-risk populations living in remote and rural areas without access to fluoridated salt or water have been reported in Brazil, 36 Chile, 37 and El Salvador. 39 Although fluoride varnishes may represent a feasible public health program for this specific population, the associated costs make them a less-suitable approach in comparison to the alternatives.
Occlusal sealants have also been used as a strategy for caries control in several LACC (Table 3) such as Costa Rica 43 and Mexico 44 , being also used in the management of caries lesions. 66 One study from Costa Rica evaluated 12-year-old students across the country and found widespread use of occlusal sealants. 43 The National Oral Health Program developed in Mexico in the early 2000s also included occlusal sealants as a strategy for caries control and mainly targeted rural communities. 45 Occlusal sealants have been proposed as a feasible strategy for children at high risk of caries and living in remote and rural areas without access to fluoridated salt or water. The most commonly used sealant materials were found to be either resins or high-viscosity glass-ionomer cements, the latter being the preferred option in LACC areas with limited access to a proper clinical environment as they can be administered as an atraumatic restorative treatment (ART). 40,44,46,47 Incorporation of this approach at an individual and community level as an initial intervention complementing a wider approach including education of the population, minimizing biofilm accumulation, and restricting sugar exposure is recommended. Documented community-based strategies for caries control using occlusal sealants were scarce in LACC except for Costa Rica and Mexico.

Conclusion
Dental caries occurs due to frequent exposure of the dental biofilm to sugars which, in turn, is also related to the development of other non-communicable diseases that can have a negative impact on the individual's health and quality of life. However, this can easily be avoided through public policies that implement evidence-based strategies to control sugar consumption in an affordable manner and targeting all population groups instead of the most affluent only. Despite widespread use of biofilm control as a regular oral hygiene measure, the prevalence of caries remains high in LACC suggesting the need for strategies that incorporate multiple approaches. Although fluoride has been shown to have anticaries potential in the presence of frequent exposure to sugars, its preventive efficacy could be higher if combined with activities to restrict sugar consumption. Fluoride delivery should be extended to the community level using water and salt, although this should also be accompanied by adequate surveillance systems. Regulating the concentration of soluble fluoride (for anticaries effects) in dentifrice formulations is necessary in order to provide the population with an effective strategy for disease control. Although the use of sealants has also been found to be effective in caries control, a thorough understanding of the disease and the role of biofilm accumulation and sugar consumption at the individual level is necessary. It is essential that each Latin American and Caribbean country understands how the various strategies may be implemented or improved at the individual, local, and/or national levels so as to suit their population needs.

Prospects for Latin America
Better awareness of the association between frequent consumption of sugars and dental caries formation must be developed through widespread dissemination of information in LACC, and strategies to reduce sugar consumption should be encouraged at the individual and community levels. Local and/or national policies should be implemented keeping in mind the sociocultural identity of each Latin American and Caribbean country, and further investment should be made in upstream, integrated population-wide strategies such as taxes on sugary drinks, and stronger regulations on advertising and promotion of sugary foods and drinks targeting children. This will not only help control dental caries incidence but also improve the overall health of the population by preventing other non-communicable diseases such as obesity, diabetes, and cardiovascular diseases.
Although the use of fluoride to control dental caries has contributed to the reduction in prevalence of dental caries in LACC over the years, its use must be monitored at the local, regional and national levels so as to achieve maximum anti-cariogenic effects while also minimizing the risk of dental fluorosis. Moreover, fluoridated water and salt programs, used as a mutually exclusive community level strategy for caries control, should expand their benefits to reach nonrecovered areas of LACC while also simultaneously providing adequate surveillance of the fluoride concentration delivered to the population. Areas with two or more simultaneous sources of fluoride intake should have one of the sources eliminated or reduced.
Although the use of fluoride dentifrices during tooth-brushing is a practice well-embedded in most urban population groups, it should also be promoted as a community level strategy among school children, rural populations, and traditional LACC groups (e.g., indigenous, quilombolas, and riverside Amazonian people) through culturally appropriate and economically sustainable policies and programs. The dentifrice formulations must have optimal levels of soluble fluoride to ensure an anti-caries effect, and the lack of specific legislations regulating the minimum concentration of fluoride in dentifrices in LACC should be addressed. The use of fluoride and occlusal sealants through individual or community level intervention programs should be incorporated into wider strategies addressing sugar consumption and biofilm control. Mouth-rinses, gels, and varnishes can be included as vehicles for fluoride and occlusal sealants in a well-planned program that combines population strategies aiming to shift the distribution of risk factors in the entire population as well as those at the highest risk of disease. Targeting culturally appropriate, economically sustainable caries control interventions to rural populations and native ethnic groups such as indigenous people, quilombolas (African-origin), and riverside Amazonian people remains a crucial challenge.