Table 3.

Main findings from included studies

Author(s), date	Main study findings
1. Abdus et al., 2019 [36]	Compared with Medicaid enrollees in states that did not provide coverage, enrollees in states that provided coverage of nonemergency dental services were approximately 9 percentage points more likely to have a dental visit, approximately 7 percentage points more likely to have any preventive dental service, and more likely to have all other types of dental services except oral surgery services. The out-of-pocket share of dental expenditure, among Medicaid enrollees with visits, was approximately 19 percentage points lower in covered states than in uncovered states. This difference was equal to approximately one-half of the out-of-pocket share of dental expenditures in uncovered states (38.50%).
2. Beil et al., 2012 [37]	Children who had a primary or secondary preventive visit by age 18-months had no difference in subsequent dental outcomes compared to children in older age categories. Among children with existing disease, those who had a tertiary preventive visit by age 18-months had lower rates of subsequent treatment (18–24 months IDR: 1.19, [95% CI: 1.03–1.38]; 25–30 months IDR: 1.21, [95% CI: 1.06 – 1.39]; 37–42 months IDR: 1.39, [95% CI: 1.22 – 1.59]) and lower treatment expenditures compared to children in older age categories. Children with existing disease who received a tertiary preventive visit by age 18 months had 19% to 39% fewer treatments per time enrolled and were predicted to have $38-$138 fewer treatment related expenditures per year from age 3½ to 6 years than children who had tertiary preventive visits at older ages.
3. Bergström et al., 2016 [38]	Caries prevalence and caries increment in 15-year-olds were significantly lower after the implementation of the programme. Group 2, without a programme, had the highest caries increment. This means that it is possible that the fluoride varnish programme, during this four-year period, prevented fillings for a total cost of 391 SEK for each individual taking part.
4. Bhayat et al., 2016 [39]	There was a mean 46% increase in attendance after primary dental health services were introduced, with more than a sixfold increase in casual attendees (pain, sepsis) than in booked patients (restorative treatment, dentures, orthodontics).
5. DiMarco et al., 2010 [40]	Shelter-based care was effective in improving access: 43% of families secured dental appointments and perceived access barriers decreased after shelter-based care (t = 54.695; p ≤ 0.001).
6. Elani et al., 2020 [41]	The Affordable Care Act (ACA) increased rates of dental coverage by 18.9 percentage points in states that provide dental benefits through Medicaid. In terms of utilization, expansion states that provide dental benefits saw the greatest increase in people having a dental visit in the past year (7.2 percentage points). However, there was no significant change in the overall share of people who had a dental visit in the past year, although the expansion was associated with a significant increase in this metric among White adults.
7. Elani et al., 2020 [42]	In states that expanded Medicaid and offered dental coverage, dental Emergency Department (ED) visits decreased by 14.1 percent (from 19,443 to 16,709, for a net difference of 2,734). By contrast, in the remaining three state groups, dental ED visits rose. Meanwhile, the expansion significantly increased Medicaid coverage and decreased the rate of self-pay for ED dental visits.
8. Kaakko et al., 2002 [43]	Utilization is described in two periods: the first period was February l, 1997, to January 31,1998, and the second period was February 1, 1998, to May 31, 1999. In the first period the utilization rate (based on one or more dental claims) was significantly higher for the ABCD group than for the group of Medicaid-enrolled children not in ABCD (34.0% vs 24.7%; chi-square = 4.5; P = .03) (Table 1). During the second period, there was no statistically significant difference in utilization rates between ABCD and Medicaid-enrolled children not in ABCD. There were no statistically significant differences in overall expenditures for dental care between the groups in either period. During the first period, annual dental care expenditures were $67.32 for ABCD children and $52.44 (P = .35) for Medicaid enrolled children not in ABCD, respectively.
9. Khouja et al., 2020 [44]	Over the study period, 37.8 percent of low-income children received at least one annual preventive dental visit. We found no change in children's receipt of preventive dental care associated with Medicaid expansions in states that covered (1.26 percentage points; 95% CI: − 3.74 to 6.27) vs did not cover preventive dental services for adults (3.03 percentage points; 95% CI: − 2.76 to 8.81). (Differential change: − 1.76 percentage points; 95% CI: − 8.09, 4.56). However, our estimates are imprecise, with wide confidential intervals that are unable to rule out sizable effects in either direction. We did not find an association between Medicaid expansions with concurrent coverage of preventive dental services for adults and children's use of these services. Factors other than parental access to dental benefits through Medicaid may be more salient determinants of preventive dental care use among low-income children.
10. Kidd et al., 2020 [45]	The universal interventions had high population reach: nursery toothbrushing (89.1%), dental practice visits (70.5%). The targeted interventions strongly favored children from the most deprived areas: Dental Health Support Worker (DHSW) contacts (Scottish Index of Multiple Deprivation (SIMD) 1: 29.5% vs SIMD 5: 7.7%), nursery Fluoride Varnish Applications (FVAs) (SIMD 1: 75.2% vs SIMD 5: 23.2%).
11. Lyu et al., 2020 [46]	Expanding Medicaid in 2014 with extensive or limited dental coverage increased preventive dental visits and use of major dental treatments by over 5 percentage-points in 2014 and 2015. The increase in preventive visits continued in 2016 in expanding states with extensive coverage, while increase in major dental treatments continued in 2016 in expanding states with limited coverage. There is some but less consistent evidence of an increase in dental treatment with emergency-only coverage
12. Maserejian et al., 2008 [47]	On average, urban children utilized 69 percent of the visits and rural children utilized 82 percent of the visits. For both sites, utilization steadily decreased until the end of the 5-year trial. Among these children with unmet dental needs, the provision of free preventive dental care was insufficient to remove the disparities in utilization and did not consistently result in high utilization through follow-up.
13. McQuade et al., 2011 [48]	While the RIte Smiles (Rhode Island’s managed oral health program) began enrolling children in September 2006, several initiatives were underway beginning in 2004 that could have impacted utilization of dental care. As such, there appears to have been a slight trend upward on dental care between 2002 and 2004; however, the major inflection points in both participation and utilization appear between 2005 and 2007—coinciding with implementation of the RIte Smiles program. In fact, there was a 28% increase in overall participation in dental care between 2005 and 2010, a 33% increase in preventive visits and a 50% increase in treatment visits.
14. Metsch et al., 2015 [49]	The odds of having a dental care visit were about twice as high in the intervention group as in the standard care group at 6 months (adjusted odds ratio [OR] = 2.52; 95% confidence interval [CI] = 1.58, 4.08) and 12 months (adjusted OR = 1.98; 95% CI = 1.17, 3.35), but the odds were comparable in the 2 groups by 18 months (adjusted OR = 1.07; 95%CI = 0.62, 1.86). We demonstrated that a dental case management intervention targeting people with HIV was efficacious but not sustainable over time.
15. Moeller et al., 2020 [50]	Our preliminary 2-year time frame investigation does not provide evidence that a Medicare dental benefit covering routine care would have cost savings by lowering medical care use and expense of the elderly. We instead found that annual use of preventive dental care by older dentate persons is correlated with higher annual use and expense for office-based visits and, as a result, with higher overall health care utilization and expenditures. We also found that older persons currently using routine dental care have healthier lifestyles and greater access to care and use of preventive medical care than current nonusers.
16. Nihtilä et al., 2013 [51]	Most heavy users (61.6%) became low users and only 11.2% remained chronic heavy users. Most low users (91.0%) remained low users. For heavy users, the mean number of dental visits per year (3.0) during the follow-upperiod was significantly lower than initially in 2004 (8.3) (p < 0.001) but 74.8% of heavy users had had emergency visits compared with 21.6% of the low users (p < 0.001). A third (33%) of the visitors in each group had no proper examination and treatment planning during the 5-year follow-up period and two or more examinations were provided to fewer than half of the heavy (46.1%) or low (46.5%) users.
17. Nowak et al., 2014 [52]	Of 42,532 subjects, 17,040 (40 percent) were early starters and 25,492 (60 percent) were late starters. There were 3.58 more dental procedures performed on late starters, over eight years of follow-up, than on early starters (P < .001). Late starters spent $360 more over eight years of follow-up than early starters (P < .001).
18. Nunez et al., 2013 [53]	Veterans who received dental care were 30% more likely than those who did not to complete the program, 14% more likely to be employed or financially stable, and 15% more likely to have obtained residential housing. Provision of dental care has a substantial positive impact on outcomes among homeless veterans participating in housing intervention programs. This suggests that homeless programs need to weigh the benefits and cost of dental care in program planning and implementation.
19. Pourat et al., 2020 [54]	We found a reduction in ratio of treatment (particularly restorative) to total services in the fourth year, given receipt of portable preventive care in the third year (direct impact) and receipt of portable preventive care in prior years (indirect impact). Older children and those covered by Medicaid (versus privately insured) had a higher ratio of treatment to total services in the fourth year. Our retrospective analysis showed CHC portable dental program may reduce the use of treatment services over time among underserved children.
20. Rozier et al., 2010 [55]	The data set included more than eleven million child-month records (in other words, one record for each month) for 629,005 Medicaid-enrolled children ages six months up to three years during the period 2000–2006. Data in Exhibits 1 and 2 reflect the gradual implementation of the program over the seven-year study period as more physicians and staff received the required training. The number of both well-child visits and oral health visits in medical offices per hundred Medicaid enrolled children increased over time within every age group (Exhibit 1). The increase was largest for children ages 12–23 months (66.2 oral health medical visits per hundred Medicaid-enrolled children). Two additional measures (not shown) reflect differences in how many children were seen by the program by age group. The percentage of children with at least one oral health medical visit in 2006 was 19.4 percent for ages 611 months, 38.8 percent for ages 12–23 months, and 17.8 percent for ages 24–35 months. The percentage of well-child visits that included oral health services in 2006 was 16.2 percent for ages 6–11 months, 35.8 percent for ages 12–23 months, and 43.0 percent for ages 2435 months, which suggests a greater likelihood of oral health services for two-year-old children if they had a well-child visit. Analysis of physician and dentist Medicaid claims from period 2000–2006 shows that the program greatly increased preventive oral health services. By 2006 approximately 30 percent of well-child visits for children ages six months up to three years included these services.
21. Sanjeevan et al., 2019 [56]	Five studies met the inclusion criteria, covering a population of 28,208 school children of which 21,447 were included in the meta-analysis. The review concludes that school based dental screening marginally increases the dental attendance by 16 percent as opposed to a non-screening group (RR 1.16 (95% CI 1.11, 1.21). The quality of evidence was found to be low.
22. Sen et al., 2013 [57]	Using data on Children’s Health Insurance Program (CHIP) enrollees in Alabama, we found that preventive dental visits reduce a child’s subsequent non preventive dental visits and expenditures compared with years when the same child had no preventive visits. Restorative services obtained during preventive visits further reduced subsequent non preventive dental visits and expenditures. However, we found no evidence that preventive dental visits generate net savings for the program, at least in the 2-year follow-up period of our study.
23. Singhal et al., 2013 [11]	Seven articles were considered eligible for this review. They varied in study design, target population and intervention studied. Overall, they presented low levels of evidence due to small sample sizes, lack of control groups, combined interventions or being based on anecdotal reports. There is a limited amount of evidence concerning the assumption that dental care can improve employment outcomes. The scarcity of well-conducted studies and the poor quality of evidence makes it difficult to judge the effect of dental care on employment outcomes. More studies need to be conducted in order to confirm or dismiss this generalized assumption.
24. Singhal et al., 2016 [58]	We received data for 8,742 people (2,742 treatment, 6,000 no-treatment). At one year, employment outcomes were not significantly different between the two groups (adjusted odds ratio = 0.93; 95% CI: 0.83–1.03). Post-hoc analysis shows that the change in proportion of individuals leaving social assistance for employment over time was significantly higher (p = 0.0014) among those receiving treatment (13–29%; 124% increase) than those not receiving treatment (18–33%; 83% increase).
25. Suominen et al., 2000 [59]	While the total number of young adults who had received reimbursement for private dental care increased from about 53,000 (1986) to 200,000 (1994) due to extended eligibility, the number of users in the youngest group decreased from 53,000 to 23,000. Attending infrequently (1–2 times during the study period) was most common among the youngest adults and frequent attendance (annually) was most common among older adults. The annual mean cost was slightly lower among the frequent attenders in almost every cohort. Variation in the mean number of annual visits was directly correlated with costs. Frequent attenders most often received diagnostic and preventive measures while restorations and surgery were most common for the infrequent attenders.