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Sealed primary molars are less likely to develop caries
Original Contributions
Cover Story Sealed primary molars are less likely to develop caries Michael Hong, DDS; Carolynn Vuong, DMD; Karin Herzog, DDS, MSD; Man Wai Ng, DDS, MPH; Rosalyn Sulyanto, DMD, MS ABSTRACT Background. The authors examined the association between light-polymerized resin-based fluoride-releasing sealants and the development of pit-and-fissure caries on primary molars. Methods. In this 3-year retrospective study, the authors reviewed the dental records of 297 children (1,352 teeth) younger than 6 years who were at high caries risk. Sealant placement or nonplacement on primary molars in the outpatient clinic and operating room setting was recorded, and random-effects logistic regression analysis accounting for the effect of data clustering was performed to measure caries incidence over time. Results. The odds of developing pit-and-fissure carious lesions on sealed primary molars were 0.055 times (95% confidence interval [CI], 0.011 to 0.285; P ¼ .001) and 0.013 times (95% CI, 0.001 to 0.159; P ¼ .001) the odds of that on nonsealed primary molars in the outpatient clinic and in the operating room, respectively. In molars that became carious, those sealed were associated with longer time to caries development in both the outpatient clinic (2.69 years, 95% CI, 2.08 to 3.29) and operating room (1.97 years, 95% CI, 1.45 to 2.48). Conclusions. Sealed primary molars were less likely to develop pit-and-fissure caries when placed in both the clinic and operating room settings. Practical Implications. Dental sealants on primary molars should be considered for children at high caries risk. Key Words. Sealants; caries incidence; primary teeth; caries prevention. JADA 2019:150(8):641-648 https://doi.org/10.1016/j.adaj.2019.04.011
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s the paradigm in dentistry shifts from a surgical intervention model to a risk-based chronic disease management approach to caries, fluoride treatments and dental sealants have emerged as the principal modalities in preventing caries. Pit-and-fissure caries account for 80% through 90% of all carious lesions in permanent teeth and 44% in primary teeth.1,2 Sealants have been shown to be superior over fluoride varnish in preventing caries on pit-and-fissure surfaces.1,2 Micromechanically bonded to pits and fissures, resin-bonded sealants effectively form a physical barrier that impedes cariogenic bacteria from accessing nutrients, thus minimizing the risk of developing cavitation.3 Results of in vivo studies have shown that sealants on permanent molars are effective in preventing pit-and-fissure caries. In a 2013 Cochrane systematic review of 12 studies, AhovuoSaloranta and colleagues4 reported that sealing permanent molars in children 5 through 10 years of age greatly reduced their risk of developing caries (odds ratio [OR], 0.12). In an earlier Cochrane report, the authors concluded that resin-based sealants in children and adolescents effectively reduced caries incidence by 86% after 1 year and 57% after 48 through 54 months.5 The overall efficacy of pit-and-fissure sealants in preventing caries was cited at 71%.6 Backed by robust evidence, both the American Dental Association (ADA) and American Academy of Pediatric Dentistry (AAPD) strongly endorse sealing pits and fissures of permanent molars.2,7 Although widely shown in the permanent dentition, the caries-preventive effect of sealants has not been validated in the primary dentition. Studies supporting pit-and-fissure sealants on primary teeth
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This article has an accompanying online continuing education activity available at: http://jada.ada.org/ce/home. Copyright ª 2019 American Dental Association. All rights reserved.
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have been limited. Although Hotuman and colleagues,8 in their study of 52 children, reported lower caries incidence in primary molars that were sealed by autopolymerized (5.9%) and light-polymerized sealants (9.8%), their study was focused primarily on examining sealant retention rates. The AAPD advocates further research owing to insufficient data in support of sealants placed on primary teeth.7-9 Since 2010, caries risk assessment has been a cornerstone of clinical practice in the Department of Dentistry at Boston Children’s Hospital (BCH). During each diagnostic or preventive visit, patients receive an assessment of their caries risk, obtained using a modified caries management by risk assessment tool, and their caries risk status is recorded as high, moderate, or low. At the same visit, carious lesions are charted using a modified International Caries Detection and Assessment System.10 An up-to-date caries risk assessment helps define a customized preventive and restorative treatment plan that is appropriate for each patient.11 In addition to recommendations for dietary changes and modulating fluoride exposure, application of sealants on susceptible pits and fissures of primary molars in children and adolescents at high caries risk had been an integral component of the philosophy of caries prevention by risk management at BCH. Then, in September 2013, Massachusetts’ combined Medicaid and State Children’s Health Insurance Program ended reimbursement of sealants on primary teeth (CMR 420.424[C]).12 With this change in insurance coverage, our department reexamined its practice of routinely placing sealants on high-risk primary molars. In the setting of a lack of evidence for placement of sealants on primary molars and the financial constraints imposed by the change in the Medicaid and State Children’s Health Insurance Program reimbursement for sealants on primary teeth, our department ended the practice of routinely placing sealants on primary molars, although sealants continue to be selectively placed on noncarious primary molars of high-risk patients receiving composite restorations in the same quadrant in the clinic or receiving treatment in the operating room. This scenario highlighted the need for further studies regarding the use of sealants in the primary dentition. The change in clinical practice also created a unique opportunity to examine the association of dental sealants placed on primary molars and subsequent pit-and-fissure caries via comparing the caries outcomes of the sealed cohort from April 1, 2009, through September 30, 2013, and nonsealed cohort from October 1, 2013, through November 1, 2016.
ABBREVIATION KEY AAPD: American Academy of Pediatric Dentistry. ADA: American Dental Association. BCH: Boston Children’s Hospital.
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METHODS This retrospective cohort study was approved by the BCH institutional review board. We collected the clinical data of all eligible patients from the Dentrix Enterprise software Version 8.0.0.203, the BCH Department of Dentistry’s electronic dental record and billing system. We generated a billing report of all patients who received a procedure code D1351 on a primary tooth from April 1, 2009, through September 30, 2013.13 We selected study participants on the basis of the following criteria: n had at least 1 primary molar that was fully erupted, had not been previously sealed or restored, and had no caries or had noncavitated caries limited to the pits and fissures; n received a resin-based sealant on at least 1 primary molar from April 1, 2009, through September 30, 2013; n younger than 6 years at the time of sealant placement; n classified as high caries risk during the baseline dental visit; n had at least 2 follow-up examinations over a minimum of 2 years to a maximum of 3 years from the initial evaluation. Primary molars were excluded from the study if they had received glass ionomer sealants or were noted to have defects such as hypomineralization, hypoplasia, or fluorosis. However, we included other molars without such defects in the same patient in the study. We generated a separate billing report for comparison patients who received more than 1 billing code of D0120, D0145, or D0150 for periodic oral evaluations, oral examinations of patients younger than 3 years, and comprehensive examinations, respectively, from October 1, 2013, through November 1, 2016. We selected the comparison patients on the basis of the following criteria: n had at least 1 primary molar that was fully erupted, had not been previously sealed or restored, had no caries, or had noncavitated caries limited to the pits and fissures; n never received a resin-based sealant during the duration of follow-up; n younger than 6 years at the time of the baseline dental visit; n classified as high caries risk during the baseline dental visit; n had at least 2 years of follow-up. JADA 150(8)
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Nonsealed molars and initial dental visit after October 1, 2013 n = 1,080
Sealed molars and initial dental visit before October 1, 2013 n = 272
Outpatient dental clinic n = 933
Operating room visit n = 147
Outpatient dental clinic n = 110
Operating room visit n = 162
Group 1
Group 2
Group 3
Group 4
Figure 1. Cohort groups included in the study. The number of patients included in each group is indicated.
Two cohorts of participants and 2 cohorts of comparison patients emerged. Group 1 consisted of comparison patients with at least 1 nonsealed primary molar who were treated from October 1, 2013, through November 1, 2016, in the outpatient dental clinic. Group 2 consisted of comparison patients with at least 1 nonsealed primary molar who were treated in the operating room under general anesthesia from October 1, 2013, through November 1, 2016. Group 3 consisted of patients who received 1 or more sealants on primary molars from April 1, 2009, through September 30, 2013, in the outpatient dental clinic. Group 4 consisted of patients who received 1 or more sealants on primary molars from April 1, 2009, through September 30, 2013, in the operating room under general anesthesia (Figure 1). The demographic variables in our analysis included age, sex, race, and dental insurance. Age was measured in years. Race was categorized as white, black, Asian, or other. Dental insurance was categorized as Medicaid or private insurance. Other patient characteristics in our analysis included the consumption of cariogenic snacks or beverages (< 3 or 3 times per day), caries experience of primary caregiver (yes or no), presence of deep pits and fissures (yes or no), community water fluoridation (yes or no), use of fluoridated toothpaste (yes or no), and topical fluoride varnish placed (yes or no) at the initial dental visit. The 2 primary outcomes of interest were caries incidence and time to caries development. We defined caries incidence as the presence of caries on the pits and fissures of primary molars penetrating the dentoenamel junction, determined clinically or radiographically on a tooth surface that did not have such a lesion before examination. For each qualifying patient, we reviewed available bite-wing radiographs, dental charting, and clinical notes for documentation of caries presence or absence for each primary molar for each recall visit date. We measured the time to caries development in years from the initial dental visit for Groups 1 and 2 or the visit of initial sealant placement for Groups 3 and 4 to the date of the recall visit when caries was recorded. Two examiners (M.H., C.V.) performed the chart reviews independently, and the reviews were compared for validity. Any differences were resolved via consensus after consulting a third examiner (R.S.). The sealants included in this study were resin-based sealants. Under cotton roll and Dri-Angle (Dental Health Products) isolation or rubber dam isolation, the teeth were etched with 37% phosphoric acid and bonded with Optibond Solo Plus (Kerr) followed by application of lightpolymerized resin-based fluoride-releasing sealant material (Ultraseal XT plus [Ultradent] or Fluoroshield [Dentsply]) and light curing for 20 through 30 seconds. We performed data analysis using Stata Version 12.1 (StataCorp) statistical software. We used descriptive statistics, including number and percentage of teeth, to evaluate the presence of sealants via categorical variables (demographic characteristics, diet, and fluoride exposure). To evaluate the association between having a sealant and demographic characteristics, diet, and fluoride exposure, we used the c2 test. To determine the association between having a sealant and use of fluoridated toothpaste, because expected cell counts were less than 5, we used the Fisher exact test. We analyzed the continuous variables, age at baseline, and time to development of new caries using mean (standard deviation [SD]) and performed 2 sample t tests with unequal variance to test the association between having a sealant and these variables. We used adjusted and unadjusted OR from random-effects logistic regression models that account for data clustering of teeth per child to examine the association between having a sealant and developing new caries. We adjusted the multivariate logistic regression model by sex, age, race, JADA 150(8)
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Table 1. Characteristics of children examined and treated in the outpatient dental clinic and in the operating room. CHARACTERISTIC
P VALUE
NO SEALANT
SEALANT
Female
386 (41.37)
48 (43.64)
d†
Male
547 (58.63)
62 (56.36)
d
Female
75 (51.02)
67 (41.36)
d
Male
72 (48.98)
95 (58.64)
d
Sex, No. of Teeth (%) Outpatient dental clinic
.649*
Operating room
.089*
Race, No. of Teeth (%) < .001*,‡
Outpatient dental clinic White
102 (10.93)
27 (24.55)
d
Asian
125 (13.40)
5 (4.55)
d
Black
299 (32.05)
30 (27.27)
d
Other and multiple
407 (43.62)
48 (43.63)
d
Operating room White
.274* 51 (34.69)
67 (41.36)
d
Asian
11 (7.48)
15 (9.26)
d
Black
20 (13.61)
28 (17.28)
d
Other and multiple
65 (44.22)
52 (32.10)
d
Medicaid
688 (73.98)
82 (82.00)
d
Private insurance
242 (26.02)
18 (18.00)
d
108 (80.00)
116 (73.89)
d
27 (20.00)
41 (26.11)
d
Health Insurance, No. of Teeth (%) Outpatient dental clinic
.079*
Operating room Medicaid Private insurance
.218*
More Than 3 Cariogenic Snacks or Drinks, No. of Teeth (%) .002*,‡
Outpatient dental clinic No
179 (19.19)
8 (7.27)
Yes
754 (80.81)
102 (92.73)
d d < .007*,‡
Operating room No
16 (10.88)
5 (3.09)
d
Yes
131 (89.12)
157 (96.91)
d
No
514 (60.61)
56 (56.57)
Yes
334 (39.39)
43 (43.43)
Primary Caregiver Has Caries, No. of Teeth (%) Outpatient dental clinic
.436* d d < .001*,‡
Operating room No
63 (47.73)
115 (72.33)
d
Yes
69 (52.27)
44 (27.67)
d
Fluoridated Water or Supplements, No. of Teeth (%) < .001*,‡
Outpatient dental clinic No
448 (48.02)
24 (21.82)
Yes
485 (51.98)
86 (78.18)
d d .002*,‡
Operating room No
79 (53.74)
59 (36.42)
d
Yes
68 (46.26)
103 (63.58)
d
* A c test was used when expected cell counts were 5. † d: Not applicable. ‡ P values of statistical significance. § A Fisher exact test was used when expected cell counts were < 5. { A 2-sample t test with unequal variance was used to test the association between having a sealant and all continuous variables. 2
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Table 1. (Continued) CHARACTERISTIC
NO SEALANT
SEALANT
P VALUE
Fluoridated Toothpaste, No. of Teeth (%) < .001‡,§
Outpatient dental clinic No
134 (14.36)
2 (1.82)
Yes
799 (85.64)
108 (98.18)
Operating room
d d .237*
No
22 (14.97)
17 (10.49)
d
Yes
125 (85.03)
145 (89.51)
d
Deep Pits and Fissures, No. of Teeth (%) < .001*,‡
Outpatient dental clinic No
768 (82.32)
52 (47.27)
Yes
165 (17.68)
58 (52.73)
d d .044*,‡
Operating room No
114 (77.55)
109 (67.28)
d
Yes
33 (22.45)
53 (32.72)
d
Age at Baseline, Y < .001‡,§
Outpatient dental clinic Patients, no. Mean (standard deviation)
933
110
3.55 (1.22)
4.76 (0.82)
d d .002‡,{
Operating room Patients, no. Mean (standard deviation)
147
162
d
3.33 (1.37)
3.76 (1.18)
d
dental insurance, cariogenic snacking frequency, primary caregiver’s caries status, water fluoridation exposure, fluoridated toothpaste use, professional topical fluoride exposure, presence of tooth decalcification, and presence of deep pits and fissures. We used Kaplan-Meier curves and Cox proportional hazards model to analyze time to event series between the groups. For all statistical analyses, we calculated 95% confidence intervals [CIs]. For this analysis, a P value of less than .05 was considered statistically significant. RESULTS A total of 297 patients and 1,352 teeth were included in this study. The cohorts were racially diverse. Most were male, had public insurance coverage, consumed 3 or more cariogenic snacks or beverages per day, did not have a primary caregiver with caries experience, and did not have deep pits and fissures on primary molars. However, most had protective fluoride exposure through fluoridated water, used fluoridated toothpaste, and received topical fluoride varnish application during recall dental visits (Table 1). The mean (SD) age of study participants treated in the outpatient clinic was 4.76 (0.82) years, and the mean (SD) age of study participants treated in the operating room was 3.76 (1.18) years (Table 1). Multivariate random-effects logistic regression analysis identified a significant association between having a sealed molar and decreased caries incidence over 3 years after adjusting for confounding factors. The odds of developing a new carious lesion in a sealed primary molar were 0.055 times the odds of having new caries in a nonsealed primary molar when a sealant was placed in the outpatient clinic (P ¼ .001) (Table 2). The odds of developing a new carious lesion in a sealed molar treated in the operating room were 0.013 times the odds of developing new caries in a nonsealed molar (P ¼ .001) (Table 2). Of the 92 sealants placed in the outpatient clinic, 4 sealants in 4 patients failed and the teeth developed caries within 3 years, yielding a 5.35% failure rate. Of the 154 primary molars sealed in the operating room, 9 primary molars in 8 patients developed caries within 3 years, accounting for a 5.84% failure rate (Table 3). Sealants in primary molars were associated with delayed time to development of cavitation. The mean time to caries development in comparison groups that did not receive sealants in the outpatient clinic and operating room was 1.48 (95% CI, 1.38 to 1.58) and 1.76 (95% CI, 1.57 to JADA 150(8)
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Table 2. The association between having a sealant and developing new caries over 3 years for children ages 1 through less than 6 years, examined and treated in the outpatient dental clinic and in the operating room.* SEALANT
UNADJUSTED
Teeth, No. Outpatient Dental Clinic
ADJUSTED
Odds Ratio (95% Confidence Interval)
P Value†
Odds Ratio (95% Confidence Interval)
P Value
845
[Reference]
.001
92
0.055 (0.011 to 0.285)
Teeth, No.
1,043
937 < .001
No
933
[Reference]
Yes
110
0.077 (0.018 to 0.325)
Operating Room
309
No
147
[Reference]
Yes
162
0.007 (0.0006 to 0.071)
247 < .001
120
[Reference]
.001
154
0.013 (0.001 to 0.159)
* The multivariate logistic regression model was adjusted by sex, age, race, dental insurance, cariogenic snacking frequency, primary caregiver’s caries status, water fluoridation exposure, fluoridated toothpaste use, professional topical fluoride exposure, presence of tooth decalcification, and presence of deep pits and fissures. † All P values are of statistical significance.
Table 3. Time to development of new caries in children treated in the outpatient dental clinic and in the operating room by age at baseline examination. CLINICAL SETTING
NO SEALANT Teeth, Mean* (Standard No. Deviation), Y
SEALANT 95% CI
Teeth, Mean* (Standard No. Deviation), Y
95% CI
P Value
Outpatient Clinic
191
1.48 (0.72)
1.38 to 1.58
4
2.69 (0.38)
2.08 to 3.29
.003†
Operating Room
71
1.76 (0.78)
1.57 to 1.94
9
1.97 (0.67)
1.45 to 2.48
.205
* Time to development of new caries measured in years. † A 1-sided 2-sample t test with unequal variance was used to test the association between having a sealant and time to development of new caries. Denotes statistical significance. CI: Confidence interval.
1.94) years, respectively. By comparison, the mean time to development of new caries for the primary molars was 2.69 (95% CI, 2.08 to 3.29) years for molars sealed in the outpatient clinic and 1.97 (95% CI, 1.45 to 2.48) years for molars sealed in the operating room (Table 3). In the few sealed primary molars that became cavitated and required a subsequent restoration, sealants delayed caries formation by 1.21 years in the outpatient clinic (P ¼ .003) and 0.21 years in the operating room (P ¼ .205). A survival analysis comparing percentage of caries-free teeth between sealed and unsealed molars in the clinic revealed that sealed primary molars had a significantly higher percentage of teeth remaining caries free (hazard ratio, 8.19; 95% CI, 3.02 to 22.18; P < .001) (Figure 2A). A survival analysis performed in the same manner in the operating room setting revealed a significantly higher percentage of sealed teeth remaining caries free (hazard ratio, 19.86; 95% CI, 9.51 to 44.46; P < .001) (Figure 2B). DISCUSSION Our retrospective study is 1 of the first to investigate caries incidence after sealant placement on primary molars. Only children at high risk of caries who were younger than 6 years at the initial visit were selected for the clinic cohorts to match the cohort of patients who required treatment of their carious lesions in the operating room. The study patients and comparison patients were stratified on the basis of whether the sealant placement was performed at the outpatient clinic or operating room. Overall, we found that sealant placement in both the outpatient clinic and the operating room was associated with reduced caries incidence in primary molars. Compared with primary molars without sealants, primary molars with sealants that were placed in the outpatient clinic or operating room settings were less likely to develop caries within 3 years of placement but after at least 2 years of follow-up. Our findings are congruent with findings of reduction of caries in permanent teeth after placement of sealants as reported by the ADA Council on Scientific Affairs and in the AAPD 2016 evidence-based clinical practice recommendations, which were developed on the basis of a systematic review of 9 randomized controlled trials.14 Despite the inherent differences between primary and permanent molars, including pit-and-fissure anatomy, enamel 646
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Dental Clinic
Operating Room 100 CARIES-FREE TEETH, %
CARIES-FREE TEETH, %
100 80 HR, 8.19; 95% CI, 3.02 to 22.18; P = .001
60 40 20
0
0.5
A
1
2 1.5 YEARS
Sealant (N = 110)
2.5
3
No Sealant (N = 933)
80 HR, 19.86; 95% CI, 9.51 to 44.46; P < .001
60 40 20
0
B
0.5
1
2 1.5 YEARS
Sealant (N = 162)
2.5
3
No Sealant (N = 147)
Figure 2. Time to new caries in unsealed versus sealed primary molars, completed in dental clinic (A) versus operating room (B). Kaplan-Meier survival analysis of time to caries development in years of cohort groups of sealant (blue) and no sealant (green) placed. HR: Hazard ratio. CI: Confidence interval.
thickness, and mineral density, the similarity in the magnitude of caries reduction between this study and the aforementioned systematic review on permanent molars underscores the potential role of sealants in preventing cariogenic bacteria from accessing nutrients and thereby reducing bacterial load.14-16 Although being placed under different clinical environments, we found that pit-andfissure sealants on primary molars were correlated highly with caries reduction in both the outpatient clinic and the operating room, which reinforces their versatility to be successful in various clinical settings. Not only was sealant placement associated with reduced caries incidence in the pits and fissures of primary molars, it was also associated with delayed caries development that required restorative treatment. In a longitudinal analysis, Shwartz and colleagues17 found that carious lesions in primary dentition take on average 12 months to progress through the outer one-half of enamel and 10 through 12 months through the inner one-half, totaling approximately 2 years. Similarly, in our study, caries progression into dentin in nonsealed primary molars took on average 1.48 and 1.76 years in the outpatient and operating room settings, respectively (Table 3). The delay in caries formation associated with sealant placement on primary molars may defer the need for restorative intervention until a child has developed the cognitive and emotional maturity to tolerate treatment in the dental chair, averting the need for advanced behavior guidance including sedation and general anesthesia. The limitations of this study include inherent biases, such as selection bias and information bias, which are commonly identified with retrospective cohort studies. In particular, chronology bias was introduced as patients with (April 2009-September 2013) and without (October 2013-November 2016) sealant placements were followed during different time frames. This variation in time was owing to a natural limitation imposed by insurance coverage changes for sealants in primary molars. In addition, caries detection was based on electronic records documented by multiple dental providers, potentially introducing variability and bias in diagnosis, charting, and treatment strategies among providers. Caries development was determined via caries charted or via a restoration planned or completed. The chronic disease management protocol first introduced to the BCH Department of Dentistry in 2010 may also have been a factor in the low failure rates and subsequent caries development in the primary teeth that received sealants in the clinic (5.85%) and in the operating room (5.84%). This protocol recommends disease management visits that include 1- through 3-month fluoride varnish applications for patients at high risk of developing caries, patient and family engagement and coaching on diet and oral hygiene modification, and use of 0.4% stannous fluoride toothpaste. Preschool-aged patients with early childhood caries who participated in the disease management protocol were found to have reduced rates of new cavitation compared with baseline patients who were not exposed to such a protocol.11 Therefore, our study results may not be generalizable to other practices that have not adopted caries prevention and management protocols. JADA 150(8)
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The findings of our study support the caries protective role of sealants on primary molars. Sealants placed on primary molars were associated with reduced caries incidence. Primary molar sealants could result in cost savings by means of reducing the need for restorative treatment. Future directions of this research can expand on the cost-effectiveness of sealants on primary molars, especially as coverage for primary molar sealants continues to be dropped from insurance programs. Reimbursement for primary molar sealants is provided by only 17 Medicaid programs in the United States, which accounts for 34% of states.18 The low-income population covered by Medicaid programs includes children who are at higher risk of developing caries. Twice as many children from households below the federal poverty threshold (as defined by the US Census Bureau) have untreated caries than do children from higher-income households (> 200% federal poverty threshold).19 Thus, expansion of research into the cost-effectiveness of primary molar sealant placement is necessary to affect evidence-based policy changes to influence oral health care access in high-risk populations. In addition, our research on primary molar sealants can be validated further through a more rigorous prospective research approach, including randomized controlled studies. A split-mouth design to examine sealed and nonsealed primary molars in the same oral environment can also eliminate confounding factors and establish a controlled testing environment. Furthermore, researchers should conduct future studies in which they track the retention of sealants, which are integral to their success. CONCLUSIONS In 2016, the ADA and AAPD jointly issued evidence-based clinical practice guidelines for the use of pit-and-fissure sealants, which strongly recommended sealing pits and fissures of occlusal surfaces of primary and permanent molars. With findings that firmly correlate dental sealants with caries incidence reduction and delay in time to development of new caries in primary molars, our study supplements the growing body of evidence that sealants should be considered in children at high risk of caries. n
Dr. Hong is a pediatric dentist, Department of Dentistry, Boston Children’s Hospital, and a lecturer, Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA Dr. Vuong is a pediatric dental resident, Division of Pediatric Dentistry, Department of Orofacial Sciences, University of California, San Francisco, CA. Dr. Herzog is a pediatric dentist, Department of Dentistry, Boston Children’s Hospital, and an instructor, Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA. Dr. Ng is the dentist-in-chief, Department of Dentistry, Boston Children’s Hospital, and an associate professor, Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA.
1. Hiiri A, Ahovuo-Saloranta A, Nordblad A, Makela M. Pit and fissure sealants versus fluoride varnishes for preventing dental decay in children and adolescents. Cochrane Database Syst Rev. 2010;3:CD003067. 2. Beauchamp J, Caufield PW, Crall JJ, et al. Evidencebased clinical recommendations for the use of pit-and-fissure sealants: a report of the American Dental Association Council on Scientific Affairs. JADA. 2008;139(3):257-268. 3. Roberts GJ. Caries and the preschool child: treatment of the preschool child in the hospital service. J Dent. 1990;18(6):321-324. 4. Ahovuo-Saloranta A, Forss H, Walsh T, et al. Sealants for preventing dental decay in the permanent teeth. Cochrane Database Syst Rev. 2013;3:CD001830. 5. Ahovuo-Saloranta A, Hiiri A, Nordblad A, Worthington H, Mäkelä M. Pit and fissure sealants for preventing dental decay in the permanent teeth of children and adolescents. Cochrane Database Syst Rev. 2004;3:CD001830. 6. Llodra JC, Bravo M, Delgado-Rodriguez M, Baca P, Galvez R. Factors influencing the effectiveness of sealants: a meta-analysis. Community Dent Oral Epidemiol. 1993; 21(5):261-268.
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Dr. Sulyanto is the director, Post-Doctoral Research, and a pediatric dentist, Department of Dentistry, Boston Children’s Hospital, and an instructor, Department of Developmental Biology, Harvard School of Dental Medicine, 300 Longwood Ave., Boston, MA 02115, e-mail Rosalyn. [email protected]. Address correspondence to Dr. Sulyanto. Disclosure. None of the authors reported any disclosures. This study was supported by the Paul Losch Fund. The authors would like to acknowledge Drs. John Dickson and Steven Ureles for thoughtful discussion and their assistance in reviewing the manuscript, Ms. Patrice Melvin for her assistance with statistical analysis, and Dr. Deepti Shroff Karhade for her assistance with data entry.
7. Guideline on Restorative Dentistry. Pediatr Dent. 2016;38:107-119. 8. Hotuman E, Rolling I, Poulsen S. Fissure sealants in a group of 3-4-year-old children. Int J Paediatr Dent. 1998; 8(2):159-160. 9. Francis R, Mascarenhas AK, Soparkar P, AlMutawaa S. Retention and effectiveness of fissure sealants in Kuwaiti school children. Community Dent Health. 2008; 25(4):211-215. 10. Ng MW SR. Chronic disease management of caries in children and the role of silver diamine fluoride. J Calif Dent Assoc. 2018;46(1):23-34. 11. Ng MW, Ramos-Gomez F, Lieberman M, et al. Disease management of early childhood caries: ECC Collaborative Project. Int J Dent. 2014;2014:327801. 12. Thorn KL. Dental manual-revised regulations about dental sealants. Available at: https://www.mass.gov/files/ documents/2016/07/qg/den-91.pdf. Accessed May 13, 2019. 13. Aravamudhan K, Pokorny F, Starnes S, Tatar C, Pulkrabek K. CDT 2019: Dental Procedure Codes. Chicago, IL: American Dental Association; 2019.
14. Wright JT, Crall JJ, Fontana M, et al. Evidencebased clinical practice guideline for the use of pit-andfissure sealants: a report of the American Dental Association and the American Academy of Pediatric Dentistry. JADA. 2016;147(8):672-682. 15. Griffin SO, Gray SK, Malvitz DM, Gooch BF. Caries risk in formerly sealed teeth. JADA. 2009;140(4):415-423. 16. De Menezes Oliveira MA, Torres CP, GomesSilva JM, et al. Microstructure and mineral composition of dental enamel of permanent and deciduous teeth. Microsc Res Tech. 2010;73(5):572-577. 17. Shwartz M, Grondahl HG, Pliskin JS, Boffa J. A longitudinal analysis from bite-wing radiographs of the rate of progression of approximal carious lesions through human dental enamel. Arch Oral Biol. 1984;29(7):529536. 18. Chi DL, Singh J. Reimbursement rates and policies for primary molar pit-and-fissure sealants across state Medicaid programs. JADA. 2013;144(11):1272-1278. 19. Dye BA, Tan S, Smith V, et al. Trends in oral health status: United States, 1988-1994 and 1999-2004. Vital Health Stat. 2007;11(248):1-92.
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Cover Story Sealed primary molars are less likely to develop caries Michael Hong, DDS; Carolynn Vuong, DMD; Karin Herzog, DDS, MSD; Man Wai Ng, DDS, MPH; Rosalyn Sulyanto, DMD, MS ABSTRACT Background. The authors examined the association between light-polymerized resin-based fluoride-releasing sealants and the development of pit-and-fissure caries on primary molars. Methods. In this 3-year retrospective study, the authors reviewed the dental records of 297 children (1,352 teeth) younger than 6 years who were at high caries risk. Sealant placement or nonplacement on primary molars in the outpatient clinic and operating room setting was recorded, and random-effects logistic regression analysis accounting for the effect of data clustering was performed to measure caries incidence over time. Results. The odds of developing pit-and-fissure carious lesions on sealed primary molars were 0.055 times (95% confidence interval [CI], 0.011 to 0.285; P ¼ .001) and 0.013 times (95% CI, 0.001 to 0.159; P ¼ .001) the odds of that on nonsealed primary molars in the outpatient clinic and in the operating room, respectively. In molars that became carious, those sealed were associated with longer time to caries development in both the outpatient clinic (2.69 years, 95% CI, 2.08 to 3.29) and operating room (1.97 years, 95% CI, 1.45 to 2.48). Conclusions. Sealed primary molars were less likely to develop pit-and-fissure caries when placed in both the clinic and operating room settings. Practical Implications. Dental sealants on primary molars should be considered for children at high caries risk. Key Words. Sealants; caries incidence; primary teeth; caries prevention. JADA 2019:150(8):641-648 https://doi.org/10.1016/j.adaj.2019.04.011
A
s the paradigm in dentistry shifts from a surgical intervention model to a risk-based chronic disease management approach to caries, fluoride treatments and dental sealants have emerged as the principal modalities in preventing caries. Pit-and-fissure caries account for 80% through 90% of all carious lesions in permanent teeth and 44% in primary teeth.1,2 Sealants have been shown to be superior over fluoride varnish in preventing caries on pit-and-fissure surfaces.1,2 Micromechanically bonded to pits and fissures, resin-bonded sealants effectively form a physical barrier that impedes cariogenic bacteria from accessing nutrients, thus minimizing the risk of developing cavitation.3 Results of in vivo studies have shown that sealants on permanent molars are effective in preventing pit-and-fissure caries. In a 2013 Cochrane systematic review of 12 studies, AhovuoSaloranta and colleagues4 reported that sealing permanent molars in children 5 through 10 years of age greatly reduced their risk of developing caries (odds ratio [OR], 0.12). In an earlier Cochrane report, the authors concluded that resin-based sealants in children and adolescents effectively reduced caries incidence by 86% after 1 year and 57% after 48 through 54 months.5 The overall efficacy of pit-and-fissure sealants in preventing caries was cited at 71%.6 Backed by robust evidence, both the American Dental Association (ADA) and American Academy of Pediatric Dentistry (AAPD) strongly endorse sealing pits and fissures of permanent molars.2,7 Although widely shown in the permanent dentition, the caries-preventive effect of sealants has not been validated in the primary dentition. Studies supporting pit-and-fissure sealants on primary teeth
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have been limited. Although Hotuman and colleagues,8 in their study of 52 children, reported lower caries incidence in primary molars that were sealed by autopolymerized (5.9%) and light-polymerized sealants (9.8%), their study was focused primarily on examining sealant retention rates. The AAPD advocates further research owing to insufficient data in support of sealants placed on primary teeth.7-9 Since 2010, caries risk assessment has been a cornerstone of clinical practice in the Department of Dentistry at Boston Children’s Hospital (BCH). During each diagnostic or preventive visit, patients receive an assessment of their caries risk, obtained using a modified caries management by risk assessment tool, and their caries risk status is recorded as high, moderate, or low. At the same visit, carious lesions are charted using a modified International Caries Detection and Assessment System.10 An up-to-date caries risk assessment helps define a customized preventive and restorative treatment plan that is appropriate for each patient.11 In addition to recommendations for dietary changes and modulating fluoride exposure, application of sealants on susceptible pits and fissures of primary molars in children and adolescents at high caries risk had been an integral component of the philosophy of caries prevention by risk management at BCH. Then, in September 2013, Massachusetts’ combined Medicaid and State Children’s Health Insurance Program ended reimbursement of sealants on primary teeth (CMR 420.424[C]).12 With this change in insurance coverage, our department reexamined its practice of routinely placing sealants on high-risk primary molars. In the setting of a lack of evidence for placement of sealants on primary molars and the financial constraints imposed by the change in the Medicaid and State Children’s Health Insurance Program reimbursement for sealants on primary teeth, our department ended the practice of routinely placing sealants on primary molars, although sealants continue to be selectively placed on noncarious primary molars of high-risk patients receiving composite restorations in the same quadrant in the clinic or receiving treatment in the operating room. This scenario highlighted the need for further studies regarding the use of sealants in the primary dentition. The change in clinical practice also created a unique opportunity to examine the association of dental sealants placed on primary molars and subsequent pit-and-fissure caries via comparing the caries outcomes of the sealed cohort from April 1, 2009, through September 30, 2013, and nonsealed cohort from October 1, 2013, through November 1, 2016.
ABBREVIATION KEY AAPD: American Academy of Pediatric Dentistry. ADA: American Dental Association. BCH: Boston Children’s Hospital.
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METHODS This retrospective cohort study was approved by the BCH institutional review board. We collected the clinical data of all eligible patients from the Dentrix Enterprise software Version 8.0.0.203, the BCH Department of Dentistry’s electronic dental record and billing system. We generated a billing report of all patients who received a procedure code D1351 on a primary tooth from April 1, 2009, through September 30, 2013.13 We selected study participants on the basis of the following criteria: n had at least 1 primary molar that was fully erupted, had not been previously sealed or restored, and had no caries or had noncavitated caries limited to the pits and fissures; n received a resin-based sealant on at least 1 primary molar from April 1, 2009, through September 30, 2013; n younger than 6 years at the time of sealant placement; n classified as high caries risk during the baseline dental visit; n had at least 2 follow-up examinations over a minimum of 2 years to a maximum of 3 years from the initial evaluation. Primary molars were excluded from the study if they had received glass ionomer sealants or were noted to have defects such as hypomineralization, hypoplasia, or fluorosis. However, we included other molars without such defects in the same patient in the study. We generated a separate billing report for comparison patients who received more than 1 billing code of D0120, D0145, or D0150 for periodic oral evaluations, oral examinations of patients younger than 3 years, and comprehensive examinations, respectively, from October 1, 2013, through November 1, 2016. We selected the comparison patients on the basis of the following criteria: n had at least 1 primary molar that was fully erupted, had not been previously sealed or restored, had no caries, or had noncavitated caries limited to the pits and fissures; n never received a resin-based sealant during the duration of follow-up; n younger than 6 years at the time of the baseline dental visit; n classified as high caries risk during the baseline dental visit; n had at least 2 years of follow-up. JADA 150(8)
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Nonsealed molars and initial dental visit after October 1, 2013 n = 1,080
Sealed molars and initial dental visit before October 1, 2013 n = 272
Outpatient dental clinic n = 933
Operating room visit n = 147
Outpatient dental clinic n = 110
Operating room visit n = 162
Group 1
Group 2
Group 3
Group 4
Figure 1. Cohort groups included in the study. The number of patients included in each group is indicated.
Two cohorts of participants and 2 cohorts of comparison patients emerged. Group 1 consisted of comparison patients with at least 1 nonsealed primary molar who were treated from October 1, 2013, through November 1, 2016, in the outpatient dental clinic. Group 2 consisted of comparison patients with at least 1 nonsealed primary molar who were treated in the operating room under general anesthesia from October 1, 2013, through November 1, 2016. Group 3 consisted of patients who received 1 or more sealants on primary molars from April 1, 2009, through September 30, 2013, in the outpatient dental clinic. Group 4 consisted of patients who received 1 or more sealants on primary molars from April 1, 2009, through September 30, 2013, in the operating room under general anesthesia (Figure 1). The demographic variables in our analysis included age, sex, race, and dental insurance. Age was measured in years. Race was categorized as white, black, Asian, or other. Dental insurance was categorized as Medicaid or private insurance. Other patient characteristics in our analysis included the consumption of cariogenic snacks or beverages (< 3 or 3 times per day), caries experience of primary caregiver (yes or no), presence of deep pits and fissures (yes or no), community water fluoridation (yes or no), use of fluoridated toothpaste (yes or no), and topical fluoride varnish placed (yes or no) at the initial dental visit. The 2 primary outcomes of interest were caries incidence and time to caries development. We defined caries incidence as the presence of caries on the pits and fissures of primary molars penetrating the dentoenamel junction, determined clinically or radiographically on a tooth surface that did not have such a lesion before examination. For each qualifying patient, we reviewed available bite-wing radiographs, dental charting, and clinical notes for documentation of caries presence or absence for each primary molar for each recall visit date. We measured the time to caries development in years from the initial dental visit for Groups 1 and 2 or the visit of initial sealant placement for Groups 3 and 4 to the date of the recall visit when caries was recorded. Two examiners (M.H., C.V.) performed the chart reviews independently, and the reviews were compared for validity. Any differences were resolved via consensus after consulting a third examiner (R.S.). The sealants included in this study were resin-based sealants. Under cotton roll and Dri-Angle (Dental Health Products) isolation or rubber dam isolation, the teeth were etched with 37% phosphoric acid and bonded with Optibond Solo Plus (Kerr) followed by application of lightpolymerized resin-based fluoride-releasing sealant material (Ultraseal XT plus [Ultradent] or Fluoroshield [Dentsply]) and light curing for 20 through 30 seconds. We performed data analysis using Stata Version 12.1 (StataCorp) statistical software. We used descriptive statistics, including number and percentage of teeth, to evaluate the presence of sealants via categorical variables (demographic characteristics, diet, and fluoride exposure). To evaluate the association between having a sealant and demographic characteristics, diet, and fluoride exposure, we used the c2 test. To determine the association between having a sealant and use of fluoridated toothpaste, because expected cell counts were less than 5, we used the Fisher exact test. We analyzed the continuous variables, age at baseline, and time to development of new caries using mean (standard deviation [SD]) and performed 2 sample t tests with unequal variance to test the association between having a sealant and these variables. We used adjusted and unadjusted OR from random-effects logistic regression models that account for data clustering of teeth per child to examine the association between having a sealant and developing new caries. We adjusted the multivariate logistic regression model by sex, age, race, JADA 150(8)
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Table 1. Characteristics of children examined and treated in the outpatient dental clinic and in the operating room. CHARACTERISTIC
P VALUE
NO SEALANT
SEALANT
Female
386 (41.37)
48 (43.64)
d†
Male
547 (58.63)
62 (56.36)
d
Female
75 (51.02)
67 (41.36)
d
Male
72 (48.98)
95 (58.64)
d
Sex, No. of Teeth (%) Outpatient dental clinic
.649*
Operating room
.089*
Race, No. of Teeth (%) < .001*,‡
Outpatient dental clinic White
102 (10.93)
27 (24.55)
d
Asian
125 (13.40)
5 (4.55)
d
Black
299 (32.05)
30 (27.27)
d
Other and multiple
407 (43.62)
48 (43.63)
d
Operating room White
.274* 51 (34.69)
67 (41.36)
d
Asian
11 (7.48)
15 (9.26)
d
Black
20 (13.61)
28 (17.28)
d
Other and multiple
65 (44.22)
52 (32.10)
d
Medicaid
688 (73.98)
82 (82.00)
d
Private insurance
242 (26.02)
18 (18.00)
d
108 (80.00)
116 (73.89)
d
27 (20.00)
41 (26.11)
d
Health Insurance, No. of Teeth (%) Outpatient dental clinic
.079*
Operating room Medicaid Private insurance
.218*
More Than 3 Cariogenic Snacks or Drinks, No. of Teeth (%) .002*,‡
Outpatient dental clinic No
179 (19.19)
8 (7.27)
Yes
754 (80.81)
102 (92.73)
d d < .007*,‡
Operating room No
16 (10.88)
5 (3.09)
d
Yes
131 (89.12)
157 (96.91)
d
No
514 (60.61)
56 (56.57)
Yes
334 (39.39)
43 (43.43)
Primary Caregiver Has Caries, No. of Teeth (%) Outpatient dental clinic
.436* d d < .001*,‡
Operating room No
63 (47.73)
115 (72.33)
d
Yes
69 (52.27)
44 (27.67)
d
Fluoridated Water or Supplements, No. of Teeth (%) < .001*,‡
Outpatient dental clinic No
448 (48.02)
24 (21.82)
Yes
485 (51.98)
86 (78.18)
d d .002*,‡
Operating room No
79 (53.74)
59 (36.42)
d
Yes
68 (46.26)
103 (63.58)
d
* A c test was used when expected cell counts were 5. † d: Not applicable. ‡ P values of statistical significance. § A Fisher exact test was used when expected cell counts were < 5. { A 2-sample t test with unequal variance was used to test the association between having a sealant and all continuous variables. 2
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Table 1. (Continued) CHARACTERISTIC
NO SEALANT
SEALANT
P VALUE
Fluoridated Toothpaste, No. of Teeth (%) < .001‡,§
Outpatient dental clinic No
134 (14.36)
2 (1.82)
Yes
799 (85.64)
108 (98.18)
Operating room
d d .237*
No
22 (14.97)
17 (10.49)
d
Yes
125 (85.03)
145 (89.51)
d
Deep Pits and Fissures, No. of Teeth (%) < .001*,‡
Outpatient dental clinic No
768 (82.32)
52 (47.27)
Yes
165 (17.68)
58 (52.73)
d d .044*,‡
Operating room No
114 (77.55)
109 (67.28)
d
Yes
33 (22.45)
53 (32.72)
d
Age at Baseline, Y < .001‡,§
Outpatient dental clinic Patients, no. Mean (standard deviation)
933
110
3.55 (1.22)
4.76 (0.82)
d d .002‡,{
Operating room Patients, no. Mean (standard deviation)
147
162
d
3.33 (1.37)
3.76 (1.18)
d
dental insurance, cariogenic snacking frequency, primary caregiver’s caries status, water fluoridation exposure, fluoridated toothpaste use, professional topical fluoride exposure, presence of tooth decalcification, and presence of deep pits and fissures. We used Kaplan-Meier curves and Cox proportional hazards model to analyze time to event series between the groups. For all statistical analyses, we calculated 95% confidence intervals [CIs]. For this analysis, a P value of less than .05 was considered statistically significant. RESULTS A total of 297 patients and 1,352 teeth were included in this study. The cohorts were racially diverse. Most were male, had public insurance coverage, consumed 3 or more cariogenic snacks or beverages per day, did not have a primary caregiver with caries experience, and did not have deep pits and fissures on primary molars. However, most had protective fluoride exposure through fluoridated water, used fluoridated toothpaste, and received topical fluoride varnish application during recall dental visits (Table 1). The mean (SD) age of study participants treated in the outpatient clinic was 4.76 (0.82) years, and the mean (SD) age of study participants treated in the operating room was 3.76 (1.18) years (Table 1). Multivariate random-effects logistic regression analysis identified a significant association between having a sealed molar and decreased caries incidence over 3 years after adjusting for confounding factors. The odds of developing a new carious lesion in a sealed primary molar were 0.055 times the odds of having new caries in a nonsealed primary molar when a sealant was placed in the outpatient clinic (P ¼ .001) (Table 2). The odds of developing a new carious lesion in a sealed molar treated in the operating room were 0.013 times the odds of developing new caries in a nonsealed molar (P ¼ .001) (Table 2). Of the 92 sealants placed in the outpatient clinic, 4 sealants in 4 patients failed and the teeth developed caries within 3 years, yielding a 5.35% failure rate. Of the 154 primary molars sealed in the operating room, 9 primary molars in 8 patients developed caries within 3 years, accounting for a 5.84% failure rate (Table 3). Sealants in primary molars were associated with delayed time to development of cavitation. The mean time to caries development in comparison groups that did not receive sealants in the outpatient clinic and operating room was 1.48 (95% CI, 1.38 to 1.58) and 1.76 (95% CI, 1.57 to JADA 150(8)
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Table 2. The association between having a sealant and developing new caries over 3 years for children ages 1 through less than 6 years, examined and treated in the outpatient dental clinic and in the operating room.* SEALANT
UNADJUSTED
Teeth, No. Outpatient Dental Clinic
ADJUSTED
Odds Ratio (95% Confidence Interval)
P Value†
Odds Ratio (95% Confidence Interval)
P Value
845
[Reference]
.001
92
0.055 (0.011 to 0.285)
Teeth, No.
1,043
937 < .001
No
933
[Reference]
Yes
110
0.077 (0.018 to 0.325)
Operating Room
309
No
147
[Reference]
Yes
162
0.007 (0.0006 to 0.071)
247 < .001
120
[Reference]
.001
154
0.013 (0.001 to 0.159)
* The multivariate logistic regression model was adjusted by sex, age, race, dental insurance, cariogenic snacking frequency, primary caregiver’s caries status, water fluoridation exposure, fluoridated toothpaste use, professional topical fluoride exposure, presence of tooth decalcification, and presence of deep pits and fissures. † All P values are of statistical significance.
Table 3. Time to development of new caries in children treated in the outpatient dental clinic and in the operating room by age at baseline examination. CLINICAL SETTING
NO SEALANT Teeth, Mean* (Standard No. Deviation), Y
SEALANT 95% CI
Teeth, Mean* (Standard No. Deviation), Y
95% CI
P Value
Outpatient Clinic
191
1.48 (0.72)
1.38 to 1.58
4
2.69 (0.38)
2.08 to 3.29
.003†
Operating Room
71
1.76 (0.78)
1.57 to 1.94
9
1.97 (0.67)
1.45 to 2.48
.205
* Time to development of new caries measured in years. † A 1-sided 2-sample t test with unequal variance was used to test the association between having a sealant and time to development of new caries. Denotes statistical significance. CI: Confidence interval.
1.94) years, respectively. By comparison, the mean time to development of new caries for the primary molars was 2.69 (95% CI, 2.08 to 3.29) years for molars sealed in the outpatient clinic and 1.97 (95% CI, 1.45 to 2.48) years for molars sealed in the operating room (Table 3). In the few sealed primary molars that became cavitated and required a subsequent restoration, sealants delayed caries formation by 1.21 years in the outpatient clinic (P ¼ .003) and 0.21 years in the operating room (P ¼ .205). A survival analysis comparing percentage of caries-free teeth between sealed and unsealed molars in the clinic revealed that sealed primary molars had a significantly higher percentage of teeth remaining caries free (hazard ratio, 8.19; 95% CI, 3.02 to 22.18; P < .001) (Figure 2A). A survival analysis performed in the same manner in the operating room setting revealed a significantly higher percentage of sealed teeth remaining caries free (hazard ratio, 19.86; 95% CI, 9.51 to 44.46; P < .001) (Figure 2B). DISCUSSION Our retrospective study is 1 of the first to investigate caries incidence after sealant placement on primary molars. Only children at high risk of caries who were younger than 6 years at the initial visit were selected for the clinic cohorts to match the cohort of patients who required treatment of their carious lesions in the operating room. The study patients and comparison patients were stratified on the basis of whether the sealant placement was performed at the outpatient clinic or operating room. Overall, we found that sealant placement in both the outpatient clinic and the operating room was associated with reduced caries incidence in primary molars. Compared with primary molars without sealants, primary molars with sealants that were placed in the outpatient clinic or operating room settings were less likely to develop caries within 3 years of placement but after at least 2 years of follow-up. Our findings are congruent with findings of reduction of caries in permanent teeth after placement of sealants as reported by the ADA Council on Scientific Affairs and in the AAPD 2016 evidence-based clinical practice recommendations, which were developed on the basis of a systematic review of 9 randomized controlled trials.14 Despite the inherent differences between primary and permanent molars, including pit-and-fissure anatomy, enamel 646
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Dental Clinic
Operating Room 100 CARIES-FREE TEETH, %
CARIES-FREE TEETH, %
100 80 HR, 8.19; 95% CI, 3.02 to 22.18; P = .001
60 40 20
0
0.5
A
1
2 1.5 YEARS
Sealant (N = 110)
2.5
3
No Sealant (N = 933)
80 HR, 19.86; 95% CI, 9.51 to 44.46; P < .001
60 40 20
0
B
0.5
1
2 1.5 YEARS
Sealant (N = 162)
2.5
3
No Sealant (N = 147)
Figure 2. Time to new caries in unsealed versus sealed primary molars, completed in dental clinic (A) versus operating room (B). Kaplan-Meier survival analysis of time to caries development in years of cohort groups of sealant (blue) and no sealant (green) placed. HR: Hazard ratio. CI: Confidence interval.
thickness, and mineral density, the similarity in the magnitude of caries reduction between this study and the aforementioned systematic review on permanent molars underscores the potential role of sealants in preventing cariogenic bacteria from accessing nutrients and thereby reducing bacterial load.14-16 Although being placed under different clinical environments, we found that pit-andfissure sealants on primary molars were correlated highly with caries reduction in both the outpatient clinic and the operating room, which reinforces their versatility to be successful in various clinical settings. Not only was sealant placement associated with reduced caries incidence in the pits and fissures of primary molars, it was also associated with delayed caries development that required restorative treatment. In a longitudinal analysis, Shwartz and colleagues17 found that carious lesions in primary dentition take on average 12 months to progress through the outer one-half of enamel and 10 through 12 months through the inner one-half, totaling approximately 2 years. Similarly, in our study, caries progression into dentin in nonsealed primary molars took on average 1.48 and 1.76 years in the outpatient and operating room settings, respectively (Table 3). The delay in caries formation associated with sealant placement on primary molars may defer the need for restorative intervention until a child has developed the cognitive and emotional maturity to tolerate treatment in the dental chair, averting the need for advanced behavior guidance including sedation and general anesthesia. The limitations of this study include inherent biases, such as selection bias and information bias, which are commonly identified with retrospective cohort studies. In particular, chronology bias was introduced as patients with (April 2009-September 2013) and without (October 2013-November 2016) sealant placements were followed during different time frames. This variation in time was owing to a natural limitation imposed by insurance coverage changes for sealants in primary molars. In addition, caries detection was based on electronic records documented by multiple dental providers, potentially introducing variability and bias in diagnosis, charting, and treatment strategies among providers. Caries development was determined via caries charted or via a restoration planned or completed. The chronic disease management protocol first introduced to the BCH Department of Dentistry in 2010 may also have been a factor in the low failure rates and subsequent caries development in the primary teeth that received sealants in the clinic (5.85%) and in the operating room (5.84%). This protocol recommends disease management visits that include 1- through 3-month fluoride varnish applications for patients at high risk of developing caries, patient and family engagement and coaching on diet and oral hygiene modification, and use of 0.4% stannous fluoride toothpaste. Preschool-aged patients with early childhood caries who participated in the disease management protocol were found to have reduced rates of new cavitation compared with baseline patients who were not exposed to such a protocol.11 Therefore, our study results may not be generalizable to other practices that have not adopted caries prevention and management protocols. JADA 150(8)
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The findings of our study support the caries protective role of sealants on primary molars. Sealants placed on primary molars were associated with reduced caries incidence. Primary molar sealants could result in cost savings by means of reducing the need for restorative treatment. Future directions of this research can expand on the cost-effectiveness of sealants on primary molars, especially as coverage for primary molar sealants continues to be dropped from insurance programs. Reimbursement for primary molar sealants is provided by only 17 Medicaid programs in the United States, which accounts for 34% of states.18 The low-income population covered by Medicaid programs includes children who are at higher risk of developing caries. Twice as many children from households below the federal poverty threshold (as defined by the US Census Bureau) have untreated caries than do children from higher-income households (> 200% federal poverty threshold).19 Thus, expansion of research into the cost-effectiveness of primary molar sealant placement is necessary to affect evidence-based policy changes to influence oral health care access in high-risk populations. In addition, our research on primary molar sealants can be validated further through a more rigorous prospective research approach, including randomized controlled studies. A split-mouth design to examine sealed and nonsealed primary molars in the same oral environment can also eliminate confounding factors and establish a controlled testing environment. Furthermore, researchers should conduct future studies in which they track the retention of sealants, which are integral to their success. CONCLUSIONS In 2016, the ADA and AAPD jointly issued evidence-based clinical practice guidelines for the use of pit-and-fissure sealants, which strongly recommended sealing pits and fissures of occlusal surfaces of primary and permanent molars. With findings that firmly correlate dental sealants with caries incidence reduction and delay in time to development of new caries in primary molars, our study supplements the growing body of evidence that sealants should be considered in children at high risk of caries. n
Dr. Hong is a pediatric dentist, Department of Dentistry, Boston Children’s Hospital, and a lecturer, Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA Dr. Vuong is a pediatric dental resident, Division of Pediatric Dentistry, Department of Orofacial Sciences, University of California, San Francisco, CA. Dr. Herzog is a pediatric dentist, Department of Dentistry, Boston Children’s Hospital, and an instructor, Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA. Dr. Ng is the dentist-in-chief, Department of Dentistry, Boston Children’s Hospital, and an associate professor, Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA.
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Dr. Sulyanto is the director, Post-Doctoral Research, and a pediatric dentist, Department of Dentistry, Boston Children’s Hospital, and an instructor, Department of Developmental Biology, Harvard School of Dental Medicine, 300 Longwood Ave., Boston, MA 02115, e-mail Rosalyn. [email protected]. Address correspondence to Dr. Sulyanto. Disclosure. None of the authors reported any disclosures. This study was supported by the Paul Losch Fund. The authors would like to acknowledge Drs. John Dickson and Steven Ureles for thoughtful discussion and their assistance in reviewing the manuscript, Ms. Patrice Melvin for her assistance with statistical analysis, and Dr. Deepti Shroff Karhade for her assistance with data entry.
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14. Wright JT, Crall JJ, Fontana M, et al. Evidencebased clinical practice guideline for the use of pit-andfissure sealants: a report of the American Dental Association and the American Academy of Pediatric Dentistry. JADA. 2016;147(8):672-682. 15. Griffin SO, Gray SK, Malvitz DM, Gooch BF. Caries risk in formerly sealed teeth. JADA. 2009;140(4):415-423. 16. De Menezes Oliveira MA, Torres CP, GomesSilva JM, et al. Microstructure and mineral composition of dental enamel of permanent and deciduous teeth. Microsc Res Tech. 2010;73(5):572-577. 17. Shwartz M, Grondahl HG, Pliskin JS, Boffa J. A longitudinal analysis from bite-wing radiographs of the rate of progression of approximal carious lesions through human dental enamel. Arch Oral Biol. 1984;29(7):529536. 18. Chi DL, Singh J. Reimbursement rates and policies for primary molar pit-and-fissure sealants across state Medicaid programs. JADA. 2013;144(11):1272-1278. 19. Dye BA, Tan S, Smith V, et al. Trends in oral health status: United States, 1988-1994 and 1999-2004. Vital Health Stat. 2007;11(248):1-92.
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