Description of Study Participants
Overall, 7,787 teeth from 2,269 patients were included in the study. We excluded from the sample patients from the overall beneficiary group whose records were missing data (See Supplemental Files Appendix 2). The majority of patients (91%) received only SDF, with 7,475 teeth receiving SDF alone (2,063 patients), 220 receiving both an SDF application and a sedative filling (185 patients), and 92 receiving SDF with a same-day restoration (76 patient, Table 1). Study participants were well-distributed by age, ranging from 1 to 64 years. The study sample disproportionately included the youngest beneficiaries relative to the overall age distribution, likely due to the high prevalence of delivery of these treatments to children (See Supplemental Files Appendix 2).
Participants aged 1 to 20 accounted for the majority of all SDF delivered (75%, Table 1). The provision of SDF generally tapered as adults progressed through working age. Half of SDF with a same-day restoration were among adults 21 and older. As expected, SDF was commonly applied to those at increased caries risk, with 45-58% of applications delivered to patients assessed to be at high caries risk and 23-34% delivered to patients who did not have a caries risk assessment within the claims record. By contrast, only 4-5% of SDF was delivered to low-risk patients.
SDF alone and SDF with a sedative filling were more often placed on primary teeth than on permanent teeth, primarily on molars (43% and 55% on lower molars, respectively, and 42% and 44% on upper, Table 1). The remaining SDF-alone placements on primary teeth were applied primarily to upper incisors and upper cuspids (8% and 4%, respectively). SDF with a same-day restoration was more often placed on permanent teeth than on primary teeth and, in particular, permanent molars (32%-38%) and upper bicuspids (18%). When SDF was applied alone at the index visit, just over a third of teeth received one or more additional SDF applications within one year (38%). An analysis of the relationship between caries risk and number of SDF applications not included in this paper shows that single applications of SDF were more common among patients whose claims record did not contain a risk assessment than among patients whose claims record contained a risk assessment (64% versus 58%, respectively). Multiple applications of SDF during the study period (three or more) were marginally more common among patients assessed to be at high risk of caries than among patients assessed to be at low or moderate risk (17% versus 13%, respectively).
Table 1: Descriptive Statistics of Teeth Treated with Silver Diamine Fluoride Only or Combined with Sedative Filling or Restoration
|
|
|
SDF
|
|
SDF + Sedative Filling
|
|
SDF + Restoration
|
|
|
Count
|
%
|
|
Count
|
%
|
|
Count
|
%
|
Total
|
7,475
|
|
|
220
|
|
|
92
|
|
Age
|
|
|
|
|
|
|
|
|
|
1-5
|
1,696
|
23%
|
|
45
|
20%
|
|
5
|
5%
|
|
6-9
|
2,374
|
32%
|
|
81
|
37%
|
|
23
|
25%
|
|
10-14
|
923
|
12%
|
|
43
|
20%
|
|
12
|
13%
|
|
15-20
|
641
|
9%
|
|
7
|
3%
|
|
6
|
7%
|
|
21-30
|
578
|
8%
|
|
13
|
6%
|
|
13
|
14%
|
|
31-40
|
427
|
6%
|
|
13
|
6%
|
|
17
|
18%
|
|
41-50
|
303
|
4%
|
|
9
|
4%
|
|
4
|
4%
|
|
51-64
|
533
|
7%
|
|
9
|
4%
|
|
12
|
13%
|
Caries Risk
|
|
|
|
|
|
|
|
|
|
No Assessment
|
1,723
|
23%
|
|
75
|
34%
|
|
18
|
20%
|
|
Low
|
401
|
5%
|
|
12
|
5%
|
|
4
|
4%
|
|
Moderate
|
1,331
|
18%
|
|
35
|
16%
|
|
17
|
18%
|
|
High
|
4,020
|
54%
|
|
98
|
45%
|
|
53
|
58%
|
# of Applications within 1 Year
|
|
|
|
|
|
|
|
|
|
1
|
4,567
|
61%
|
|
186
|
85%
|
|
82
|
89%
|
|
2
|
1,827
|
24%
|
|
25
|
11%
|
|
8
|
9%
|
|
3+
|
1,081
|
14%
|
|
9
|
4%
|
|
2
|
2%
|
Primary vs. Permanent
|
|
|
|
|
|
|
|
|
|
Primary
|
4,152
|
56%
|
|
131
|
60%
|
|
27
|
29%
|
|
Permanent
|
3,323
|
44%
|
|
89
|
40%
|
|
65
|
71%
|
Tooth Type - Primary Teeth
|
|
|
|
|
|
|
|
|
|
Lower Incisor
|
35
|
1%
|
|
0
|
0%
|
|
0
|
0%
|
|
Lower Cuspid
|
59
|
1%
|
|
0
|
0%
|
|
0
|
0%
|
|
Lower Molar
|
1,801
|
43%
|
|
72
|
55%
|
|
15
|
56%
|
|
Upper Incisor
|
350
|
8%
|
|
1
|
1%
|
|
2
|
7%
|
|
Upper Cuspid
|
161
|
4%
|
|
1
|
1%
|
|
1
|
4%
|
|
Upper Molar
|
1,746
|
42%
|
|
57
|
44%
|
|
9
|
33%
|
Tooth Type - Permanent Teeth
|
|
|
|
|
|
|
|
|
|
Lower Incisor
|
84
|
3%
|
|
0
|
0%
|
|
0
|
0%
|
|
Lower Cuspid
|
86
|
3%
|
|
1
|
1%
|
|
1
|
2%
|
|
Lower Bicuspid
|
490
|
15%
|
|
7
|
8%
|
|
4
|
6%
|
|
Lower Molar
|
1,001
|
30%
|
|
31
|
35%
|
|
21
|
32%
|
|
Upper Incisor
|
160
|
5%
|
|
1
|
1%
|
|
1
|
2%
|
|
Upper Cuspid
|
85
|
3%
|
|
3
|
3%
|
|
1
|
2%
|
|
Upper Bicuspid
|
514
|
15%
|
|
8
|
9%
|
|
12
|
18%
|
|
Upper Molar
|
903
|
27%
|
|
38
|
43%
|
|
25
|
38%
|
Survival Analyses
SDF alone had an overall survival rate of 76%, while SDF with a sedative filling had a survival rate of 50% and SDF with a same-day restoration has a survival rate of 84%. These survival rates are significantly different with both the Wilcoxon and Log-Rank tests (Table 2). Kaplan-Meier estimates of SDF survival alone and with a restoration remained above 90% survival to 162 days and 215 days, respectively, with SDF alone holding its overall survival rate of 76% well beyond a year, to day 446 (Figure 1). SDF applied with a sedative filling fell below 90% at day 80 and remained at 58% at one year after application.
Table 2: Comparisons of Survival Rates of Teeth treated with SDF Applications Alone vs. SDF Application with Same Day Restoration among Advantage Dental Patients 64 and Under
|
|
|
SDF Survival %
|
SDF+Sedative Filling Survival %
|
SDF + Restoration Survival %
|
Overall
|
76%
|
50%
|
84%
|
# of SDF Applications within One Year
|
|
|
|
|
1
|
75%
|
49%
|
84%
|
|
2
|
77%
|
56%
|
--
|
|
3+
|
75%
|
33%
|
--
|
Caries Risk
|
|
|
|
|
Low
|
81%
|
50%
|
--
|
|
Moderate
|
76%
|
51%
|
82%
|
|
High
|
75%
|
42%
|
79%
|
|
No Assessment
|
75%
|
59%
|
94%
|
Age
|
|
|
|
|
1-5
|
69%
|
53%
|
--
|
|
6-9
|
77%
|
57%
|
61%
|
|
10-14
|
84%
|
53%
|
83%
|
|
15-20
|
82%
|
29%
|
100%
|
|
21-30
|
76%
|
23%
|
92%
|
|
31-40
|
77%
|
31%
|
100%
|
|
41-50
|
72%
|
33%
|
50%
|
|
51-64
|
68%
|
44%
|
92%
|
Primary vs. Permanent
|
|
|
|
|
Primary Tooth
|
74%
|
56%
|
74%
|
|
Permanent Tooth
|
78%
|
40%
|
88%
|
Tooth Type - Primary Teeth
|
|
|
|
|
Lower Incisor
|
74%
|
--
|
--
|
|
Lower Cuspid
|
86%
|
--
|
--
|
|
Lower Molar
|
71%
|
51%
|
73%
|
|
Upper Incisor
|
77%
|
--
|
--
|
|
Upper Cuspid
|
83%
|
--
|
--
|
|
Upper Molar
|
75%
|
60%
|
67%
|
Tooth Type - Permanent Teeth
|
|
|
|
|
Lower Incisor
|
70%
|
--
|
--
|
|
Lower Cuspid
|
69%
|
--
|
--
|
|
Lower Bicuspid
|
82%
|
29%
|
100%
|
|
Lower Molar
|
80%
|
39%
|
81%
|
|
Upper Incisor
|
50%
|
--
|
--
|
|
Upper Cuspid
|
69%
|
--
|
--
|
|
Upper Bicuspid
|
75%
|
--
|
100%
|
|
Upper Molar
|
82%
|
47%
|
88%
|
Note: Cells are empy if sample size is less than 10. Failure is defined as a restoration or extraction after application. Sedative fillings are not considered to be failures if they occur within 70 days of initial application. Survival is defined as a patient that returned 180 or more days after application and had no restoration or extraction. Equality of Survivor Tests for Overall Rate Between SDF Applications: Wilcoxon Test, 79 (2 df), p<0.000; Log-Rank Test, 91.5 (2 df), p<0.000)
|
SDF survival varied little based on the number of applications. However, there is substantial variation across other categories (Table 2). SDF alone survived well on all primary teeth with lower molars (71%) having the lowest survival rate and lower and upper primary cuspids (86% and 83%, respectively) performing well. SDF alone performed well on permanent molars (80-82%) and bicuspids (82-75%), with lower survival rates on incisors and cuspids. SDF survival rates also varied across age categories. It performed well among those aged 10 to 20 years (83%). Survival rates were substantially lower among young children and adults age 41 and older. With regard to risk assessment, SDF survival was highest among patients with a low risk assessment (81%), while patients with a moderate risk assessment met the overall survival rate (76%). SDF survival among patients aged 6 to 40 years old and among patients with a high-risk assessment or lacking a risk assessment in their record fell short of the overall survival rate by one percentage point (75%). While this analysis presents results by tooth, outcomes at the patient level are consistent with tooth level, with survival rates of 72%, 47%, and 85% of SDF alone, SDF with a sedative filling, and SDF with a same-day restoration, respectively.
Table 3: Cox Proportional Hazards Regressions Estimating Silver Diamine Fluoride Failure among Advantage Dental Patients 64 and Under
|
|
|
Haz. Ratio
|
95% C.I.
|
Robust Clustered S.E.
|
Type of Application (Reference: SDF Alone):
|
|
|
|
|
|
SDF+Sedative Filling Survival %
|
2.48
|
***
|
2-3.06
|
0.27
|
|
SDF + Restoration Survival %
|
0.60
|
|
0.33-1.08
|
0.18
|
# of SDF Applications (Reference: One):
|
|
|
|
|
|
2
|
0.93
|
|
0.78-1.11
|
0.08
|
|
3
|
0.98
|
|
0.77-1.24
|
0.12
|
Caries Risk (Reference: Low)
|
|
|
|
|
|
No Assessment
|
1.36
|
|
0.95-1.93
|
0.24
|
|
Moderate
|
1.34
|
|
0.92-1.94
|
0.25
|
|
High
|
1.42
|
***
|
1.03-1.97
|
0.24
|
Age (Reference: 6-9)
|
|
|
|
|
|
1-5
|
1.33
|
**
|
1.07-1.65
|
0.15
|
|
10-14
|
0.77
|
|
0.57-1.02
|
0.11
|
|
15-20
|
0.94
|
|
0.62-1.43
|
0.20
|
|
21-30
|
1.37
|
|
0.93-2.03
|
0.27
|
|
31-40
|
1.29
|
|
0.82-2.05
|
0.30
|
|
41-50
|
1.66
|
*
|
1.09-2.55
|
0.36
|
|
51-64
|
1.79
|
***
|
1.23-2.62
|
0.35
|
Tooth Type - Primary Teeth (Reference: Lower Molar)
|
|
|
|
|
|
Lower Incisor
|
0.66
|
|
0.23-1.91
|
0.36
|
|
Lower Cuspid
|
0.40
|
*
|
0.18-0.89
|
0.16
|
|
Upper Incisor
|
0.61
|
**
|
0.43-0.87
|
0.11
|
|
Upper Cuspid
|
0.51
|
**
|
0.33-0.78
|
0.11
|
|
Upper Molar
|
0.86
|
*
|
0.75-0.98
|
0.06
|
Tooth Type - Permanent Teeth (Reference: Lower Molar)
|
|
|
|
|
|
Lower Incisor
|
1.22
|
|
0.8-1.86
|
0.26
|
|
Lower Cuspid
|
1.17
|
|
0.72-1.88
|
0.28
|
|
Lower Bicuspid
|
0.77
|
*
|
0.6-0.98
|
0.10
|
|
Upper Incisor
|
2.65
|
***
|
1.89-3.72
|
0.46
|
|
Upper Cuspid
|
1.35
|
|
0.89-2.04
|
0.28
|
|
Upper Bicuspid
|
1.17
|
|
0.9-1.52
|
0.16
|
|
Upper Molar
|
0.86
|
|
0.7-1.06
|
0.09
|
|
|
|
|
|
|
Number of Teeth
|
7,787
|
|
|
|
Number of Patients
|
1,957
|
|
|
|
Likelihood Ratio Chi-Square
|
154.48
|
***
|
22 df
|
|
Note: * p<.05; **p<.01; ***p<.001.
|
|
|
|
|
Among those with SDF applied with a sedative filling, survival rates by category never exceeded 60%. Moreover, SDF with a sedative filling failed at 2.5 times the rate of SDF alone, even after controlling for number of applications, caries risk, age, and tooth type and location and accounting for the multilevel design of the data (HR 2.49, p<.001, Table 3). This finding most likely is reflective of the interim nature of sedative fillings in current dental practice. Survival rates were highest among those under age 14 and lowest among patients between 15 and 50 years of age. SDF applied with a same-day restoration had the overall highest survival rates, with some categories reaching 100%, although the small sample size (n=92) is important to keep in mind as is the intended longevity of the procedure and the potential selection bias of application only to teeth likely to succeed with this treatment.
Table 4: Procedures Performed on Teeth that Fail after SDF Application among Advantage Dental Patients 64 and Under
|
|
Panel A: SDF Alone
|
|
Overall
|
Permanent vs. Primary
|
Tooth Type - Permanent Teeth
|
|
Prim.
|
Perm.
|
L. Incisor
|
L. Cuspid
|
L. Bicuspid
|
L. Molar
|
U. Incisor
|
U. Cuspid
|
U. Bicuspid
|
U. Molar
|
Minor Restoration
|
39%
|
36%
|
68%
|
64%
|
74%
|
68%
|
65%
|
68%
|
69%
|
70%
|
69%
|
Major Restoration
|
29%
|
43%
|
8%
|
8%
|
0%
|
10%
|
12%
|
6%
|
4%
|
4%
|
6%
|
Endodontics
|
1%
|
0%
|
2%
|
4%
|
7%
|
1%
|
1%
|
1%
|
0%
|
3%
|
1%
|
Extraction
|
21%
|
20%
|
22%
|
16%
|
19%
|
20%
|
21%
|
25%
|
27%
|
21%
|
23%
|
Other
|
0%
|
0%
|
1%
|
8%
|
0%
|
1%
|
0%
|
0%
|
0%
|
2%
|
0%
|
Total
|
1,831
|
1,094
|
737
|
25
|
27
|
87
|
204
|
80
|
26
|
128
|
160
|
|
Panel B: SDF + Sedative Filling
|
|
Panel C: SDF + Restoration
|
|
|
|
Overall
|
Permanent vs. Primary
|
Tooth Type - Permanent Teeth
|
|
Overall
|
Permanent vs. Primary
|
|
|
|
Prim.
|
Perm.
|
L. Molar
|
U. Molar
|
|
Prim.
|
Perm.
|
|
|
Minor Restoration
|
39%
|
10%
|
70%
|
53%
|
80%
|
|
60%
|
71%
|
50%
|
|
|
Major Restoration
|
41%
|
66%
|
15%
|
21%
|
10%
|
|
13%
|
29%
|
0%
|
|
|
Endodontics
|
3%
|
0%
|
6%
|
5%
|
5%
|
|
13%
|
0%
|
25%
|
|
|
Extraction
|
17%
|
24%
|
9%
|
21%
|
5%
|
|
13%
|
0%
|
25%
|
|
|
Other
|
0%
|
0%
|
0%
|
0%
|
0%
|
|
0%
|
0%
|
0%
|
|
|
Total
|
111
|
58
|
53
|
19
|
20
|
|
15
|
7
|
8
|
|
|
SDF applied to patients who had a high caries risk was likely to fail at approximately one-and-a-half times the rate of SDF applied to low-risk patients (HR 1.42, p<0.001). SDF was significantly more likely to fail among patients aged 1-5 years and older than 41 years of age, when compared with those aged 6-9. On primary teeth, lower molars had significant higher rates of failure than other teeth, but no statistically significant difference from lower incisors. On permanent teeth, lower bicuspids were about 25% less likely to fail than lower molars, while upper incisors were about 2.7 times more likely to fail (HR .77, p<05 and HR 2.65, p<.001). There were no significant differences in failure rates by number of applications.
This study also assessed procedures performed on teeth on which SDF failed (Table 4). When SDF was applied alone, minor restorations were the most common procedures overall, performed on 39% of all failed applications, followed by major restorations (29%) and extractions (21%). Among primary teeth, the most common procedure following an SDF failure among teeth treated with SDF alone and in combination with a same-day sedative filling was a major restoration (43% and 66% respectively), while among permanent teeth it was a minor restoration (68% and 70%). When combined with a same-day restoration, the most common procedure associated with a failure was a minor restoration. The permanent teeth most commonly extracted following SDF alone were upper bicuspids (27%), although this accounts for a fairly small number of cases (n=26). Among the permanent tooth type with the most instances of SDF failure alone (lower molars, n=204), minor restorations remained the most common subsequent procedure (65%), followed by extractions (21%), and major restorations (12%). Endodontic procedures were relatively uncommon across the entire sample.