Topical Fluoride Effectiveness in High Caries Risk Adults

Abstract

This retrospective analysis of longitudinal data was developed to determine which types, combinations, and intensities of topical fluorides more effectively prevent new caries-related restorations and extractions in high caries risk adults. We included data from October 1, 2008, through June 30, 2018, from electronic dental and medical records and pharmacy database from the US Department of Veterans Affairs. Veterans who were eligible for continuing and comprehensive care, met the criteria of high caries risk (received 2 or more caries-related restorations within a 365-d period), and had 3 y of follow-up were included. Multivariable logistic regression models estimated the odds of caries-related treatment during the 1-y observation period, controlling for age, gender, race and ethnicity, illness burden (Selim comorbidity index), use of prescription medications, attendance at dental prophylaxis appointments, number of caries-related restorations during the index year, and time between first and last caries-related restoration during the index year. The study sample included 68,757 veterans, who were primarily male (91.5%), were White (73.6%), had a mean age of 59.2 ± 13.5 y, and had significant medical comorbidity as measured by the Selim index (3.7 ± 2.4 physical and 1.3 ± 1.2 mental diagnoses). They had 10.8 ± 6.3 prescription VA drug classes, took 0.6 ± 0.8 strong anticholinergic medications, and had 3.9 ± 2.6 teeth restored due to caries during the index year. Adjusted multivariable logistic regression models showed veterans who received a varnish or gel/rinse fluoride intervention versus no fluoride had an approximately 29% decreased odds of receiving caries-related treatment during the observation period (gel/rinse adjusted odds ratio [AOR] = 0.72; 95% confidence interval [CI], 0.67–0.76; varnish AOR = 0.71; 95% CI, 0.67–0.75). The receipt of a varnish and gel/rinse did not demonstrate statistically better odds than each intervention alone (AOR = 0.69; 95% CI, 0.64–0.75). A dose–response effect was observed. Two-plus applications of varnish versus none (AOR = 0.73; 95% CI, 0.69–0.77) and 2-plus applications of gel/rinse versus none (AOR = 0.71; 95% CI, 0.67–0.75) were more effective than 1 application of either modality versus none.

Introduction

Dental caries continues to pose a significant challenge for older Americans (Dye et al. 2007, 2015; Griffin et al. 2021) and adults worldwide (Vos et al. 2012). Among the 50 most common diseases evaluated by the Global Burden of Disease Study, dental caries ranked as the most prevalent condition. Furthermore, this study found a dental caries prevalence rate of 35.3% for both males and females (Vos et al. 2012). Restoring cavities does not stop or slow the carious disease process, nor does it significantly lower the bacterial challenge in the mouth (Locker 1996). The effectiveness of fluoride in preventing dental caries in children has been long recognized (National Institutes for Health 2001; Marinho et al. 2003). However, for caries prevention in adults, the American Dental Association (ADA) recommendations for topical fluoride use are based on expert opinion, extrapolating the evidence from permanent teeth of children and adolescents since so few studies exist in adults (Weyant et al. 2013). In order to fill this critical gap in knowledge, the ADA identified the need for research regarding fluoride effectiveness in adults, particularly in subpopulations of adults such as persons at highest risk of developing caries, persons older than 65 y, and adults at extremely high risk of developing caries. The ADA also highlighted the need for comparative effectiveness studies of different fluoride strategies in these populations. However, large-scale prospective studies on adult caries outcomes are costly and lengthy. Moreover, as dental caries is a multifactorial disease process, such studies also need to collect data on key factors such as medical comorbidities, medication use, access to preventive dental services, and race/ethnicity.

This study takes advantage of a unique opportunity to use data from extensive electronic medical and dental records from the US Department of Veterans Affairs (VA). The data represent a rich repository of clinical dental and general health data and provide the prospect of linking medical, dental, pharmacy, and laboratory records. Furthermore, unlike other dental care delivery systems, within VA Dentistry, an International Classification of Diseases, Ninth Revision (ICD-9)/International Classification of Diseases, Tenth Revision (ICD-10) diagnostic code must be recorded to denote the underlying disease for each dental treatment provided. The objective of this study was to determine which types, combinations, and intensities of fluoride were more effective at preventing new caries-related restorations and extractions in veterans at high risk for dental caries.

Methods

Study Design and Data Sources

The study was a retrospective analysis of longitudinal data from October 1, 2008, through June 30, 2018, using data from the VA electronic dental and medical records and the pharmacy database. The start date of October 1, 2008, was selected because choosing ICD-9 diagnostic codes became mandatory for dental treatment within VA Dentistry. The analytic dataset was created from VA data files from several sources: the Dental Reporting and Analytics System (housed by the Corporate Data Warehouse [CDW] and the Office of Dentistry), the VA Medical SAS Datasets (both Inpatient and Outpatient), the Inpatient and Outpatient CDW Production Datasets, VA’s Managerial Cost Accounting System, the CDW Patient Domain, and the Veterans Health Administration Vital Status Files, all housed by the CDW. The study complies with the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) guidelines for reporting observational studies (von Elm et al. 2007).

Study Sample

Veterans eligible for continuing and comprehensive care between October 1, 2008, and June 30, 2018, who met the criteria of high caries risk (i.e., received 2 or more caries-related restorations within a 365-d period [the index year]) were included. Previous research in this adult population demonstrated that the identification of at least 2 carious lesions within the current year (index year) was a highly significant predictor of future caries (Jurasic et al. 2021). Furthermore, the study was limited to veterans who did not receive any caries-related dental treatment or a fluoride intervention in the year prior to the index year (washout period) and had a follow-up period of 1 y following the index year. Thus, to be eligible for the study, veterans needed 3 y of follow-up time. The conceptual model for the study is shown in the Figure.

Figure.

Conceptual model of the study.

Primary Outcome

The primary outcome of interest was new caries-related restorations and extractions per person in the year following the index year, as a binary and a continuous outcome. This treatment was identified using both the American Dental Association’s Code on Dental Procedures and Nomenclature (CDT code) and ICD-9/10 caries diagnostic codes. VA dentists are required to choose at least 1 ICD-9/10 code to define the current disease state that led to the need for the required dental treatment. The ICD-9 caries diagnostic codes used were those in the 521 series, and the ICD-10 codes were in the K02 series. Restorative care rendered for any other diagnostic code (e.g., cracked tooth or missing restoration) was not included in this analysis. Using CDT codes, we evaluated teeth for receipt of single-tooth direct and indirect restorations and extractions.

Interventions

These were professionally applied or prescription (Rx) self-applied fluoride treatment during the index year. Professional fluoride treatments include 5% sodium fluoride (NaF) varnish (22,600 ppm fluoride), identified by CDT code 1206; 2% NaF gel or rinse (9,050 ppm fluoride), identified by CDT codes 1204 and 1208; and 1.23% acidulated phosphate fluoride (APF) gel (12,300 ppm fluoride), identified by CDT codes 1204 and 1208. The Rx 1.1% NaF paste/gel (5,000 ppm fluoride) for home use is available at all VAs through the national formulary and is dispensed through the VA Pharmacy, and these data are available in the VA’s Managerial Cost Accounting System. The use of fluoride in VA dental clinics is driven by the fluoride quality monitor/indicator for patients at high risk for caries. The choice of fluoride intervention (gel/rinse, varnish, or 1.1% NaF paste/gel) is at the discretion of the provider in consultation with the patient.

Covariates

Covariates in the analyses included the following socioeconomic variables: age, gender, race, and ethnicity. Medical complexity or illness burden was measured using the Selim comorbidity index, which was developed and validated in the veteran ambulatory population (Selim et al. 2002, 2004). The index comprises a physical component (30 medical condition diagnoses) and a mental component (6 psychiatric condition diagnoses). The comorbidities include all ICD-9/10 codes recorded in a 2-y period that include the index year and the year following the index year. Medication burden was determined by counting the number of different VA drug classes prescribed for a period of at least 30 d during the same 2-y period. The VA drug classification system provides general categories of drugs and mostly follows the American Hospital Formulary Service Drug Information classes (Stroupe et al. 2017).

To assess the issue of salivary hypofunction due to prescription medication use, we used the list of drugs with strong anticholinergic properties identified in the 2015 Beers Criteria (American Geriatrics Society Beers Criteria Update Expert Panel 2015). Of the 52 drugs identified by the Beers Criteria, 45 are available through the VA Pharmacy. Although the Beers Criteria were developed for use in older adults, the VA population is considered “young old” chronologically and presents with greater comorbidity than the general population; therefore, the use of the Beers Criteria is appropriate. The use of preventive dental services over the same 2-y period was included as a proxy for positive dental health behaviors and includes attendance at dental prophylaxis appointments (D1110, D4341, D4342, D4355, and D4910). Other included covariates were those related to the patient’s caries risk status and include a count of caries-related restorations in the index year and the time in restorative care, or the time between first and last restoration in the index year.

Statistical Analyses

Exploratory data analyses computed univariate statistics and graphs to examine the distributional characteristics of each analysis variable. Bivariate analyses included a cross-tabulation of each type of fluoride intervention with predictor variables and the outcome of interest. Pearson and Spearman correlation coefficients were calculated for covariates of interest. Multivariable logistic regression modeled receipt of new caries-related restorations or extractions during the 1-y follow-up period. The logistic regression models also explored the effect of geographic clustering of clinics and the effect of interaction terms between any pair of variables where effect modification was hypothesized. The multivariable logistic regression models included all covariate variables, including age, gender, race, ethnicity, comorbidity indices, number of VA drug classes, medications with strong anticholinergic properties, number of dental prophylaxis appointments, number of restorations in the index year, and the time between first and last restoration in the index year. All analyses were conducted using SAS/STAT software (version 9.4; SAS Institute).

Institutional Review Board

Institutional review board (IRB) approval was obtained from the Boston University Medical Campus (H-37854), the prime award recipient, and the IRB at the VA Bedford Healthcare System in Bedford, Massachusetts.

Results

Study Sample

The analytic dataset (Appendix Figure 1) resulted in a sample size of 68,757 veterans; descriptive statistics of the study sample are presented in Table 1, for the study population overall and stratified by receipt/nonreceipt of a fluoride intervention. Overall, the study cohort of 68,757 veterans had a mean age of 59 ± 13.5 y and was primarily male (91.5%) and of White race (73.6%). They had a mean of 3.7 ± 2.4 physical and 1.3 ± 1.2 mental comorbidities and were taking on average 10.8 ± 6.3 VA prescription drug classes and 0.6 ± 0.8 medications with strong anticholinergic properties. Participants had a mean of 3.9 ± 2.6 caries-related restorations during the index year and attended 2.2 ± 1.8 prophylaxis appointments during the study period. When stratified according to receipt/nonreceipt of a fluoride intervention, given the large sample size, many covariates were statistically significantly different between the 2 groups (Table 1). The most notable differences include the number of restorations during the index year (3.4 ± 2.1 in the no-fluoride group versus 4.0 ± 2.6 in the fluoride intervention group. Furthermore, veterans in the fluoride intervention group attended more prophylaxis appointments (2.6 ± 1.8) than those in the no-fluoride group (0.9 ± 1.3).

Table 1.

Characteristics of the Study Sample.

	Mean ± SD or Frequency (%)
Characteristic	Full Study Cohort (N = 68,757)	No Fluoride (n = 14,346)	Any Fluoride (n = 54,411)	P Value
Age, y	59.2 ± 13.5	58.6 ± 14.2	59.3 ± 13.3	<0.0001
Gender
Male	62,906 (91.5)	13,017 (90.8)	49,888 (91.7)	0.0007
Female	5,811 (8.5)	1,312 (9.2)	4500 (8.3)
Race
American Indian or Alaska Native	874 (1.3)	181 (1.3)	693 (1.3)	0.0002
Asian	693 (1.0)	160 (1.1)	533 (1.0)
Black/African American	15,409 (22.7)	3,395 (24.1)	12,014 (22.4)
Native Hawaiian or other Pacific Islander	911 (1.3)	189 (1.3)	722 (1.3)
White	49,944 (73.6)	10,183 (72.2)	39,761 (74.0)
Ethnicity
Hispanic	3,987 (5.8)	864 (6.0)	3,123 (5.7)	0.1971
Non-Hispanic	64,770 (94.2)	13,482 (94.0)	51,288 (94.3)
Physical comorbidity index (Selim)	3.7 ± 2.4	3.5 ± 2.4	3.7 ± 2.4	<0.0001
Mental comorbidity index (Selim)	1.3 ± 1.2	1.3 ± 1.2	1.3 ± 1.2	0.7343
VA drug classes	10.8 ± 6.3	10.3 ± 6.3	11.0 ± 6.2	<0.0001
Medications with strong anticholinergic properties	0.6 ± 0.8	0.6 ± 0.8	0.6 ± 0.8	0.1412
Dental prophylaxes	2.2 ± 1.8	0.9 ± 1.3	2.6 ± 1.8	<0.0001
Restorations during index year	3.9 ± 2.6	3.4 ± 2.1	4.0 ± 2.6	<0.0001
Time between first and last restoration in index year	114.0 ± 118.7	82.1 ± 108.6	122.4 ± 119.8	<0.0001

Missing n = 41 for Selim comorbidity index, VA drug classes, and medications with strong anticholinergic properties; missing n = 40 for age; and missing n = 926 for race.

VA, US Department of Veterans Affairs.

Fluoride Interventions

The distribution of mutually exclusive fluoride interventions is presented in Table 2. Of veterans who received a fluoride intervention, the majority received a varnish (n = 17,030) or a gel/rinse (n = 14,813). A total of 14,346 veterans did not receive any type of fluoride intervention during the index year. A small proportion of veterans (n = 6,328) received only 1.1% NaF self-applied toothpaste, and the remaining (n = 12,449) received a combination of the 3 fluoride interventions.

Table 2.

Fluoride Intervention Groups.

Fluoride Type: Mutually Exclusive Groups	n	%
Varnish	17,030	24.8
Gel/rinse	14,813	21.5
None	14,346	20.9
Varnish + gel/rinse	3,791	5.5
1.1% NaF	6,328	9.2
Varnish + 1.1% NaF	6,487	9.4
Gel/rinse + 1.1% NaF	4,455	6.5
Varnish + gel/rinse + 1.1% NaF	1,507	2.2

NaF, sodium fluoride.

Outcome

A mean of 0.87 ± 1.82 caries-related restorations and extractions was observed for the study cohort. Two-thirds (66.3%) of veterans did not have any caries-related treatment, 14.0% had 1 tooth treated, 7.9% had 2 teeth treated, 4.5% had 3 teeth, and 7.4% had 4+ teeth treated with caries-related restorations or extractions during the outcome measurement year.

Bivariable and Multivariable Analyses

A cross-tabulation of the fluoride interventions with all covariates and the outcome (Appendix Table 1) showed that dental prophylaxes count, time, between first and last restoration during the index year, Selim physical comorbidity index, total medication count, and total restorations during the index year had the greatest variability across the different fluoride interventions. Spearman correlation results showed the strongest correlation to be between all fluoride modalities and dental prophylaxes count (r = 0.42). Unadjusted logistic regression models did not demonstrate a clustering effect for geographic location of the dental clinics. We evaluated the impact of the interaction between fluoride intervention types (gel/rinse, gel/rinse + Rx, etc.) and dental prophylaxes (1vs0, 2vs0, 3+vs0) and found the interaction term to be highly significant (df = 21, Wald χ² = 299.697, P < .0001). The final logistic regression models were therefore constructed with dental prophylaxes as a categorical variable to understand its effects on the outcome.

In adjusted multivariable logistic regression models, veterans who received a varnish or gel/rinse fluoride intervention versus no fluoride had approximately 29% decreased odds of receiving caries-related treatment during the observation period (gel/rinse adjusted odds ratio [AOR] = 0.72; 95% confidence interval [CI], 0.67–0.76; varnish AOR = 0.71; 95% CI, 0.67–0.75). The receipt of a varnish and gel/rinse did not demonstrate better odds than each intervention alone (AOR = 0.69; 95% CI, 0.64–0.75). Receipt of prescription 1.1% NaF toothpaste/gel for self-application was not beneficial in preventing future caries-related treatment (AOR = 1.03; 95% CI, 0.96–1.10), and adding the prescription toothpaste to any of the other fluoride interventions slightly increased the odds of receiving caries-related treatment during the observation period (Table 3). Furthermore, we found a beneficial dose–response relationship for the varnish and gel/rinse fluoride interventions (Table 4). Two-plus applications of varnish versus none (AOR = 0.73; 95% CI, 0.69–0.77) and 2-plus applications of gel/rinse versus none (AOR = 0.71; 95% CI, 0.67–0.75) were more effective than 1 application of either modality versus none (varnish: AOR = 0.84; 95% CI, 0.81–0.88; gel/rinse: AOR = 0.87; 95% CI, 0.83–0.91). Finally, veterans who received either 1 versus no prescriptions (AOR = 1.10; 95% CI, 1.04–1.15) or 2-plus versus no prescriptions (AOR = 1.13; 95% CI, 1.08–1.18) for the 1.1% NaF toothpaste/gel did not benefit from the intervention and had the highest odds of requiring caries-related treatment among all of the intervention groups.

Table 3.

Multivariable Logistic Regression Model Estimating Odds of Future Caries-Related Treatment, for Mutually Exclusive Fluoride Interventions, N = 67,808.

Effect (Fluoride Groups Are Mutually Exclusive)	AOR Point Estimate	95% Wald Confidence Limits	P Value
Varnish vs. none	0.71	0.67–0.75	<0.0001
Gel/rinse vs. none	0.72	0.67–0.76	<0.0001
Varnish + gel/rinse vs. none	0.69	0.64–0.75	<0.0001
1.1% NaF vs. none	1.03	0.96–1.10	0.4125
Varnish + 1.1% NaF vs. none	0.81	0.76–0.87	<0.0001
Gel/rinse + 1.1% NaF vs. none	0.80	0.74–0.86	<0.0001
Varnish + gel/rinse + 1.1% NaF vs. none	0.85	0.76–0.95	0.0061

Logistic regression model adjusted for age, gender (male = reference, female); race* (American Indian/Alaska Native, Asian, Black/African American, Native Hawaiian/Pacific Islander, White = reference), ethnicity* (not Hispanic = reference, Hispanic), Selim mental comorbidity index, Selim physical comorbidity index*, number of VA drug classes*, number of medications with strong anticholinergic properties*, number of dental prophylaxes (0 = reference, 1, 2, 3+)*, time between first and last restoration during index year*, and total restorations during index year*. (*Indicates statistically significant at P < .05.) Outcome: caries-related treatment yes = 22,908, no = 44,900. Model fit statistics: adjusted R² = 0.12; c-statistic = 0.68.

AOR, adjusted odds ratio; NaF, sodium fluoride.

Table 4.

Multivariable Logistic Regression Model Estimating Odds of Future Caries-Related Treatment, Evaluating a Dose–Response Relationship of Various Fluoride Modalities, N = 67,806.

Effect	AOR Point Estimate	95% Wald Confidence Limits	P Value
Gel/rinse 1 vs. 0	0.87	0.83–0.91	<0.0001
Gel/rinse 2+ vs. 0	0.71	0.67–0.75	<0.0001
Varnish 1 vs. 0	0.84	0.81–0.88	<0.0001
Varnish 2+ vs. 0	0.73	0.69–0.77	<0.0001
1.1% NaF 1 vs. 0	1.10	1.04–1.15	0.0004
1.1% NaF 2+ vs. 0	1.13	1.08–1.18	<0.0001

Logistic regression model adjusted for age, gender (male = reference, female), race* (American Indian/Alaska Native, Asian, Black/African American, Native Hawaiian/Pacific Islander, White = reference), ethnicity* (not Hispanic = reference, Hispanic), Selim mental comorbidity index, Selim physical comorbidity index*, number of VA drug classes*, number of medications with strong anticholinergic properties*, number of dental prophylaxes (0 = reference, 1, 2, 3+)*, time between first and last restoration during index year*, and total restorations during index year*. (*Indicates statistically significant at P < .05.) Outcome: caries-related treatment yes = 22,908, no = 44,898. Model fit statistics: adjusted R² = 0.12; c-statistic = 0.68.

AOR, adjusted odds ratio; NaF, sodium fluoride.

Discussion

This study is one of the first to report results on the effectiveness of various in-office applied fluoride treatments for caries prevention in high caries risk adults. The beneficial results of in-office applied 5% NaF varnish and 2% NaF gel/rinse or 1.23% APF gel are consistent with results reported by Cochrane Systematic Reviews regarding the effectiveness of varnish (Marinho et al. 2013) and gel (Marinho et al. 2015) in the permanent teeth of children and adolescents. Furthermore, our study found a dose–response relationship, with 2-plus in-office applied fluoride treatments/y providing greater benefit than a yearly application for caries prevention in high caries risk adults.

The lack of effectiveness of the 1.1% NaF observed in our study is in contrast to the effectiveness shown for the other forms of fluoride. Of the 27% of veterans who received a prescription for 1.1% NaF self-applied toothpaste, 47% received 1 prescription/y, 22% received 2 prescriptions/y, and 31% received 3+ prescriptions/y. This prescription/refill rate is lower than the 3 to 4/y suggested for typical once daily use. Although prescription fluoride paste/gel is part of ADA recommendations (Weyant et al. 2013), there appears to be a disconnect between the presumed efficacy and the clinical effectiveness of this treatment. A previous systematic review on supplemental fluoride use for moderate and high caries risk adults (Gibson et al. 2011) found beneficial effects of 1.1% NaF for root caries in older adults. However, the studies in that review had different application modalities and included using the 1.1% NaF gel in trays or overdentures 1×/d for 5 min, brushing with paste 1×/d or 2×/d. It is therefore difficult to determine the optimum application mode and frequency for effectiveness of this product in clinical practice. Issues surrounding patient selection, patient compliance, and education should be further evaluated to address the poor outcome associated with this prescription treatment modality. Furthermore, our study showed that attendance at dental prophylaxes appointments was an important driver for the receipt of in-office applied fluoride. Given this observation and the lack of effectiveness of the 1.1% NaF found in this study, in-office applied fluoride may be a better option for caries prevention in high caries risk patients.

Previous studies have shown that VA dental patients are more medically complex and have a higher burden of disease than the general US population (Boehmer et al. 2001; Jones et al. 2001; Jurasic et al. 2019). VA Dentistry uses a primary dental provider model, with each general dentist assigned responsibility for the care of a panel of patients. This means that in most cases, a single general dentist will be responsible for care decisions made with the patient. Furthermore, VA Dentistry is prevention focused and has standardized its preventive approach across all VA dental clinics with recommendations for dental exam frequency, periodontal recall visits, and application of fluoride. These processes are monitored with quality indicators as well as flags in the patients’ electronic dental record if the patient has not met any of these measures. In 2008, VA Dentistry instituted a fluoride quality performance measure for high caries risk veterans. Research showed that overall, this increased attention and use of fluoride are associated with a decreased need for future restorations, but the type and frequency of fluoride use were not known (Gibson et al. 2014). This quality performance measure led to increased use of in-office and self-applied fluoride for caries prevention in VA dental services and has contributed to the availability of data for this study. However, our study presents with several limitations. First, we were unable to account for the total number of teeth at risk for each veteran as this information is not aggregated from the individual dental clinics to the national level. Second, we could not account for other fluoride exposures such as drinking water or over-the-counter fluoridated toothpaste. Third, we were unable to evaluate the oral hygiene status or diet and/or sugar consumption. Fourth, we were unable to identify and include any incipient lesions that may have remineralized. Fifth, we could not distinguish between 2% NaF gel/rinse and 1.23% APF gel as they are identified by the same CDT code. However, anecdotal evidence from dental clinics suggests that rinse may be more common as it has more patient acceptance in an older population with multiple medical comorbidities. Sixth, our study relied on data collected previously during routine patient care. However, the VA has numerous quality control measures related to dental clinical workload capture, including quarterly review of each clinician’s notes and clinical data, and a coding committee reviews coding trends and identifies outliers. Finally, the study population is primarily male, thus potentially limiting generalizability to the general population. However, our study population can be compared to the gender distribution in the general US population, wherein the rate of untreated dental caries in the 45- to 64-y age group for 2015–2018 was 25.3%, but when stratified for gender, it was 28.1% for males and 22.6% for females (National Center for Health Statistics 2019). The ADA’s 2013 executive summary of clinical recommendations for topical fluoride caries preventive agents had a specific call to action for data that evaluated effectiveness for high caries risk subgroups. We believe our study contributes knowledge in this area by focusing on a population that is older, more medically compromised, and identified as being at high risk for future caries.

Conclusion

In this longitudinal cohort study of high caries risk adults that evaluated the effectiveness of various types of topically applied fluorides in a clinical setting, professionally applied fluorides (fluoride varnish and gel/rinse) were significantly associated with a decreased need for future caries-related restorations or extractions. In addition, a dose–response relationship was observed for these treatments, with 2 or more treatments in a 12-mo period associated with the greatest decrease in need for caries-related treatment during the following year. Finally, the use of 1.1% sodium fluoride paste/gel was not associated with the same decrease in need for future caries-related treatment, and this discrepancy between efficacy and effectiveness requires further evaluation.

Author Contributions

M.M. Jurasic, contributed to conception, design, data analysis and interpretation, drafted the manuscript; G. Gibson, J.A. Jones, H.J. Cabral, contributed to conception, design, data analysis and interpretation, critically revised the manuscript; M.B. Orner, contributed to data acquisition, analysis, and interpretation, critically revised the manuscript; C.J. Wehler, contributed to data interpretation, critically revised the manuscript. All authors gave final approval and agree to be accountable for all aspects of the work.