Abstract
Untreated dental caries in children is one of the most common diseases and largest public health problems in the world. A novel caries management program, using 50% silver nitrate, 38% silver diamine fluoride, and 5% sodium fluoride varnish, was developed at Shoreview Dental, LLC, a private dental practice in Oregon USA, and then introduced into schools in Ecuador, Ghana, and Bolivia. Cavitated carious lesions were treated with 50% silver nitrate, followed by covering with 5% sodium fluoride varnish, three times over two weeks for 165 children in Ecuador at initial assessment, 3 months, and 6 months. This protocol was repeated for 271 children in Ghana at initial assessment and 12 months. In Bolivia, 130 children were treated with 38% silver diamine fluoride, followed by covering with 5% sodium fluoride varnish, once per visit at initial assessment, 6, 12, 18, 24, 30, and 36 months. The percentage of children with active cavitated carious lesions at initial evaluation was 92.7% (Ecuador), 55.4% (Ghana), and 92.3% (Bolivia). The final arrest rate of treated surfaces was 98.8% (Ecuador), 67.6% (Ghana), and 90.2% (Bolivia). Effectiveness of cavitated caries lesion arrest is increased when it is thoroughly cleaned and dried before the treatment protocol. Further optimization is obtained when this protocol is repeated multiple times.
Author Contributions
Copyright© 2020
R. Duffin Steven, et al.
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Competing interests Dr. Steven R. Duffin and Marcus L. Duffin are principle members of NoDK, LLC. This company focuses on the dissemination of the medical management of caries protocol to populations throughout the world. They are also authors and editors of the SMART Oral Health: The Medical Management of Caries textbook.
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Introduction
The term “caries” is used to represent a bacteria-mediated disease and the term “caries lesion” represents the physical manifestation of this disease at the tooth surface level. Untreated caries represents a major public health challenge that impacts more than half a billion children globally. In developing countries, a vast majority of caries lesions go untreated due to a limited dental workforce and limited access to expensive traditional dental restorative treatment. This situation applies especially in low-income and rural communities. The medical management of caries utilizing silver nitrate (SN) was introduced between 1880 and 1908.6 For unknown reasons, this approach to treating tooth infections (caries lesions) with medicine was abandoned during the mid-twentieth century. The successful implementation of the medical management of caries protocol at the private dental practice Shoreview Dental, LLC in Keizer, Oregon, involving the placement of 25% SN (Gordon Labs) followed by 5% sodium fluoride varnish (FV) (Centrix, Fluorodose), was described in the Journal of the California Dental Association (CDA) in 2012. In the 1960’s, Dr. R. Yamaga and colleagues combined the benefits of silver and fluoride into one compound, 38% silver diamine fluoride (38% SDF) (Saforide). A majority of the current literature on the use of silver ion compounds for the arrest of caries lesions is based on the use of 38% SDF. This is a case report on humanitarian efforts to introduce SN and SDF, followed by fluoride varnish, treatment protocols for children living in rural communities in Ecuador, Ghana, and Bolivia. These projects were accomplished in a professional manner through collaboration with schools and in partnership with parents, local community leadership, school officials and health authorities at both the national and local level. The purpose of these projects was to demonstrate the effectiveness of protocols based on the medical management of caries
Materials And Methods
All patients received comprehensive instructions on promoting healthy food choices and good oral hygiene practices. Toothbrushes were donated to all of the participating schools to help maintain good oral health. Examples of clinical treatment settings in Ecuador, Ghana and Bolivia can be seen in Following publication of the CDA paper in 2012, on the medical management of caries, The treatment protocol involved carefully cleaning with a toothbrush and thoroughly drying all cavitated caries lesions using compressed air, followed by the application of 50% SN (Gordon Laboratories) by scrubbing with a microbrush then covering with FV (Centrix, Fluorodose) to protect from saliva contamination. The lesions received three separate treatments over two weeks. This protocol of three treatments was repeated at three and six months. Intraoral images were collected for the maxillary and mandibular arches for all children at each time point ( In early 2015, the Shoreview team was invited by the Paramount Chief, Nene Nuer Keteku III, and the Queen Mother, Manye Sebezo IV, of the Agotime Traditional Area located in the Volta region in Ghana, to conduct the same humanitarian program that was conducted in Ecuador. This was of particular interest since Ghana has such a low number of practicing dentists relative to the overall population. The same materials, treatment frequency, and protocol used in Ecuador was replicated in Ghana. Evaluation and treatment were conducted at initial examination and at 12 months. Intraoral images of maxillary and mandibular arches were collected for all patients at each time point ( Emergency services were provided on-site where abscessed teeth were removed with local anesthesia at the school. School officials were instructed to find a nearby dentist to provide endodontics and complex restorative procedures when necessary. A surprising finding in this population was that most children had excellent oral health with very few cavitated caries lesions in their dentitions ( In 2016, the Seattle based Non-Governmental Organization (NGO), Smiles Forever Foundation, in collaboration with the Shoreline Community College Dental Hygiene School, started a humanitarian project in Villa Tunari within the Chapare Amazon region of rural Bolivia. The chosen location for this project was the Maria del Rosario school, where a total of 130 children participated. The prevalence and severity of caries in Bolivian children is among the highest in the world, and is not that dissimilar from what was observed in Ecuador. Just before the 6-month timepoint in early 2017, the Shoreview Dental, LLC team was invited to participate in this project. The Shoreview Dental, LLC team s role, as a partner organization to Smiles Forever, was to provide further training on the proper identification of arrested cavitated caries lesions following treatment. Upon arrival, The Shoreview Dental, LLC team presented the topic of the medical management of caries to the Medical, Dental, and Public Health community at Universidad Prevada Abierto Latino America (UPAL) Dental University in Cochabamba. Following this presentation, UPAL faculty members decided to participate in the project. Their role was to observe and participate, as a partnering institution with Smiles Forever, in the treatment of cavitated caries lesions and identification of lesion arrest. The treatment protocol used in Bolivia differed from what was used in Ecuador and Ghana. The protocol that was used involved the following: carefully clean the cavitated caries lesion using a toothbrush, thoroughly dry using compressed air, apply 38% SDF by scrubbing with a microbrush applicator, then cover with FV to prevent saliva contamination. Since access to electricity was available at the school, mobile dental equipment with a reliable compressed air source was available. This protocol was repeated at the timepoints of 6, 12, 18, 24, 30, and 36 months. Intraoral images of maxillary and mandibular arches were collected for all patients present at 36 months ( The first project in Ecuador utilized 50% SN followed by FV in early 2015 because that was the established protocol at the Shoreview Dental, LLC dental clinic and 38% SDF was not yet cleared to market by the FDA. The same protocol used in Ecuador was utilized in Ghana in late 2015 for reasons of consistency. However, 38% SDF was used in Bolivia in 2016 because the Smiles Forever Foundation had started using it before Shoreview Dental, LLC officially became a part of the program. In addition, SDF was becoming more widely used due to FDA clearance, and there is more published literature about SDF when compared to SN. Although these three humanitarian community outreach programs were not conducted as research, and should be looked at as separate case reports, careful attention to data collection was made at initial examination and at all follow up encounters. The Shoreview Dental, LLC team exclusively conducted data analysis on outcomes data related to Ecuador and Ghana but collaborated with the Smiles Forever Foundation for data analysis related to Bolivia. Surface specific charting and maxillary and mandibular arch photos were taken at all timepoints in Ecuador and Ghana but only at 36 months in Bolivia. A determination of all cavitated caries lesion activity or arrest was recorded based on lesion color and surface hardness. A lesion was considered arrested if the color was black and the surface was determined to be hard using gentle tactile examination (
Results
The results discussed below are derived from A total of 165 children, ranging from 3 to 18 years old, attended initial evaluation where 93.9% of the children had active cavitated caries lesions. The average number of teeth with active cavitated lesions was 5.6 at the initial evaluation and 0.5 at the final evaluation (6 months). The average number of surfaces with active cavitated lesions was 9.9 at the initial evaluation and 0.6 at the final evaluation. The arrest rate for teeth with cavitated caries lesions was 98.9% at the final evaluation. The arrest rate for tooth surfaces with cavitated caries lesions was 99.0% at the final evaluation. A total of 271 children, ranging from 3 to 14 years old, attended initial evaluation where 43.2% of the children had active cavitated caries lesions. The average number of teeth with active cavitated lesions was 1.4 at the initial evaluation and 0.8 at the final evaluation (12 months). The average number of tooth surfaces with active cavitated lesions was 1.7 at the initial evaluation and 1.2 at the final evaluation. The arrest rate for teeth with cavitated caries lesions at the final evaluation was 71.9%. The arrest rate for tooth surfaces with cavitated caries lesions at the final evaluation was 71.1%. A total of 130 children, ranging from 4 to 16 years old, attended the initial evaluation where 95.4% of the children had active cavitated caries lesions. The average number of teeth with active lesions was 7.3 at the initial evaluation and 2.5 at final evaluation (36 months). The average number of surfaces with active cavitated caries lesions was 8.6 at the initial evaluation and 3.9 at the final evaluation. The arrest rate for teeth with cavitated caries lesions was 72.9% at the first follow-up (6 months) and 92.5% at the final evaluation. The arrest rate for tooth surfaces with cavitated caries lesions was 73.6% at the first follow-up and 93.4% at the final evaluation. Both Ecuador and Ghana programs utilized the same treatment protocol involving three treatments per visit using 50% SN followed by FV for a total of nine treatments over six months in Ecuador and six treatments over 12 months in Ghana. However, there was a difference between the percentage of arrested cavitated caries lesions. Ecuador had a final tooth surface arrest rate of 99.0% while Ghana had a final tooth surface arrest rate of 71.1%. Ecuador also received three treatments at 3-month intervals over 6 months while Ghana received three treatments at initial and 12 months. The Bolivian program utilized a treatment protocol that involved one treatment per visit of 38% SDF followed by FV at 6-month intervals, for a total of seven treatments over 36 months, and had a final tooth surface arrest rate of 93.4%.
Ecuador
Ghana
Bolivia
Initial
3 M
6 M
Initial
12 M
Initial
6 M
12 M
18 M
24 rs4 130 M
36 M
Children
165
158
161
271
206
130
104
60
37
33 32
22
%Children Absent
0%
4.20%
2.40%
0%
24.00%
0%
20.00%
53.80%
71.50%
74.6% 75.4%
83.10%
96 Children with Active Cavitated Caries Lesions
93.90%
8.90%
25.50%
43.20%
26.20%
95.40%
85.60%
73.30%
56.8%
90.996 1
65.60%
68.20%
Non-arrested Teeth
930
8
9
385
82
947
221
87
28
27
26
15
Non-arrested Surfaces
1,626
11
14
455
99
1117
247
94
29
27
15
New Decayed Teeth
0
11
69
0
75
0
194
159
30
81
31
41
New Decayed Surfaces
0
15
88
0
147
0
270
197
34
104
40
70
Average Decayed Teeth
5.6
0.1
0.5
1.4
0.8
7.3
4
4.1
1.6
3.3
1.8
2.5
Average Decayed Surfaces
9.9
0.2
0.6
1.7
1.2
8.6
5
4.9
1.7
4.0
2.1
3.9
Arrested Teeth
0
864
839
0
210
0
594
471
383
342
339
185
Arrested Surfaces
0
1399
1333
0
243
0
688
519
404
380
411
211
% Arrested Teeth
0%
99.1%
98.90%
0%
71.90%
0%
72.90%
84.4%
93.2%
92.7%
92.90%
92.50%
%Arrested Surfaces
0%
99.2%
99.00%
0%
71.10%
0%
73.60%
84.7%
93.3%
93.1%
93.80%
93.40%
Discussion
The percent of children with active cavitated caries lesions in Ecuador, Ghana and Bolivia at the initial evaluation was 93.9%, 43.2%, and 95.4% ( One commonality that was observed across all three countries was the sale of junk food, candy, and SSB in and/or around the schools ( When analyzing the effectiveness of the treatment protocols used in these countries, it was hypothesized that the high level of success in cavitated caries lesion arrest rates, as seen in Ecuador and Bolivia, may be due to the application protocol. The similar rates of cavitated caries lesion arrest between Ecuador and Bolivia show that the 50% SN followed by FV protocol provides similar results to the 38% SDF followed by FV protocol. It is hypothesized that Ecuador had a higher rate of cavitated caries lesion arrest than Bolivia due to the following points: The Ecuadorian Ministry of Health dentists received hands on training at the Shoreview Dental, LLC clinic and Shoreview staff provided further training on-site in Ecuador. The same dentists also participated at each treatment date. In Bolivia, treatment and charting was done by Bolivian dentists and dental hygienists as well as dental hygiene students and instructors from the US. The students rotated between treatment stations and their composition varied from year to year. This could have resulted in some variation of protocol and charting consistency due to the complex nature of managing all of the various providers. In Ghana, there was no electricity available for compressed air and the manually powered compressed air system used had some limitations in obtaining total lesion desiccation prior to the application of 50% SN followed by FV. In Shoreview Dental s experience, removing saliva contamination from the lesion using compressed air, before the application protocol, is critical to obtaining a high level of success. It is hypothesized that saliva contamination prevents the silver ion from penetrating deep into the lesion via capillary action. The proteins in saliva may also sequester away the silver ions due to the reactive/chemical nature of ionic silver. It is possible that the limited ability to thoroughly dry the cavitated caries lesions in Ghana resulted in a lower arrest rate when compared to Ecuador and Bolivia, where consistent access to compressed air was available. To further prevent saliva contamination, patients were instructed to not eat or drink for at least one hour after treatment and to not brush their teeth until the next day. It is hypothesized that the application of FV over 50% SN or 38% SDF provides a hydrophobic barrier for saliva. Eating or drinking right after treatment could physically remove that barrier and allow for saliva contamination, depending on the diet. Not brushing their teeth until the next day adds another level of protection from the physical removal of FV. The longer the FV is undisturbed, the greater the likelihood that the treated cavitated caries lesion would remain uncontaminated by saliva, giving the silver ions more time to interact with and penetrate deeper into the lesion. On follow up visits in Ecuador, Ghana, and Bolivia, parents and teachers reported that the children who were treated in this manner experienced less mouth pain. They also stated that there was little concern about the black stain on the treated lesion. This corresponds with earlier observations at the Shoreview Dental, LLC clinic. In Bolivia, some patients had their arrested cavitated caries lesions, which were black and hard to the touch, covered with glass ionomer cement in the anterior aesthetic zone or on large lesions in posterior teeth. This kind of intervention has come to be known as Silver Modified Atraumatic Restorative Treatment (SMART). Recent additions to the literature suggest that a shift is taking place in the dental profession towards prevention and minimal intervention.
Conclusion
The dramatic difference in severity of tooth decay between school children living in Ghana (low) and Ecuador/Bolivia (high) is worthy of further investigation. Preventing saliva contamination by thoroughly drying the cavitated caries lesion before treatment appears to be critical in obtaining a high level of success in cavitated caries lesion arrest, as observed in the humanitarian project in Ghana. The FV may provide a hydrophobic barrier to saliva contamination for the treated surface. It is hypothesized that the longer the varnish remains on the lesion after treatment, the lower the chance of saliva contamination and the higher the chance of active cavitated caries lesion arrest. Ensuring that the patients do not eat or drink for at least one hour after treatment and wait until the next day before they brush their teeth may help in further preventing saliva contamination. Providing three treatments in a short period of time (Ecuador: nine total treatments at 3-month intervals over 6 months) versus only one treatment (Bolivia: 7 total treatments at 6 month intervals over 36 months) improves the cavitated caries lesion arrest outcomes. A similar level of cavitated caries lesion arrest was observed when comparing treatment protocols using 50% SN followed by FV and 38% SDF followed by FV. The literature had previously shown that the application of 25% SN followed by FV provides similar results to the application of 38% SDF. The effective and low-cost cavitated caries lesion intervention, using silver ion compounds followed by FV, should be given high consideration in future oral health programs. The caries lesion arrest properties of these interventions have been well documented.