Silver Diamine Fluoride (SDF) – Magic Liquid Against Tooth Decay?

Contemporary dentistry is trying to find ways to treat damaged or decayed teeth without invasively drilling and filling. That’s exciting! A paradigm shift, from a surgical-focussed approach to a more biological / physician-type approach to dentistry is long overdue.

One treatment that has become popular with dental and oral health practitioners in the last few years is silver diamine fluoride (SDF) (1,2). The United States Food and Drug Administration approved the use of Advantage Arrest (38% SDF) in dental care in 2014. In Australia, there is SDI Riva Star. 

Silver Diamine Fluoride,  available most commonly at 38% SDF (24-28% weight/volume silver, 5% weight/volume fluoride, 8% ammonia,  pH 10), applied every 3-4mths or 1-3 times per year, is currently recommended by dental bodies such as the American Academy of Pediatric Dentistry  for “the arrest of cavitated caries lesions in primary teeth as part of a comprehensive caries management program” (3,4). 

Silver diamine fluoride is a colourless liquid with a slightly bitter taste. The exact mechanism of action of SDF is not completely known but research evidence supports that SDF works as an antibacterial to stop the decay process and as a mineralizing agent to reduce demineralization and harden the softened decay part of the tooth via its fluoride and silver components (6,7). Used stringently, SDF is regarded as non-toxic and does not cause systemic side effect when as per manufacturer’s recommendations (3,5). 

SDF has actually been around for a long time (8). It has frequently been used in the Asian-Pacific countries like Japan, and also in dental outreach clinics as well as developing countries for over 40yrs (8). One reason SDF has not been a mainstream treatment in countries like Australia and USA, is because SDF causes treated decayed teeth to turn permanently black in colour (3,4). The black discolouration may be reduced significantly or alleviated by the application of potassium iodide solution immediately after application of SDF (9). The black discolouration may also be masked by subsequent restorations e.g. composite resin or glass ionomer restoration, white preformed crowns. If SDF comes into contact with other surfaces such as clothing, skin, oral soft tissues (mucosa), staining occurs. However, skin and mucosa pigmentation is temporary and will resolve in 1-2wks (4). 

The decay arrest rate using SDF is approximately 70% (47-90% reported in recent research studies, treatment on front teeth generally more successful than posterior teeth)(3,7,8,10-12). SDF has been shown to be more acceptable to parents when used for posterior teeth (13). The treatment is less expensive e.g. $50 per treatment, compared to restorations or extractions e.g. upwards of $150 per treatment. 

The treatment using SDF is much quicker and simpler than drilling and filling but it still requires patient cooperation.  For SDF to be effective, it must be applied to contact the areas of decay for long enough for the chemical reactions to take place. SDF treatment in carried out as follows:

• Remove plaque and debris to allow SDF to contact decayed tooth 
• Protect gingiva and oral mucosa to prevent discolouration and/or irritation
• Dry the decayed tooth with air
• Apply SDF 
• Dry the SDF treated tooth with air for 1min
• Avoid disturbance to application site by not immediately drinking or brushing teeth
• Review after 2-4wks - reapplication may be necessary to sustain arrest 

However SDF alone is not enough to effectively manage the disease of tooth decay. SDF does not guarantee complete arrest of existing tooth decay and SDF does not prevent new tooth decay. Tooth decay is best managed by addressing the multiple risks involved in causing tooth decay. Risks of tooth decay vary from person to person. Identifying and targeting these risks through multiple strategies including oral hygiene, diet control, lifestyle changes, etc.  is needed to manage tooth decay effectively.

SDF is recommended for (4): 

• “high caries risk patients with anterior or posterior active cavitated lesions.
• Cavitated caries lesions in individuals presenting with behavioural or medical management challenges.
• Patients with multiple cavitated caries lesions that may not be treated in one visit.
• Difficult to treat cavitated dental caries lesions.
• Patients without access to or with difficulty accessing dental care.
• Active cavitated caries lesions with no clinical signs of pulp involvement.”

For patients with metal allergy, particularly silver hypersensitivity, SDF is contraindicated. SDF is also not recommended in severe tooth decay where the pulp is involved. SDF is also best avoided when there are open wounds, gingival inflammation or ulcers in the mouth to avoid the risk of irritations.

So, would I, as a paediatric dentist, use SDF if my child had tooth decay?  

In short, I would. I would give SDF a try for my child if 1-2 primary teeth had tooth decay. If the problem was more severe than 1-2 teeth, or if there is a tooth with deep decay – I would choose restorative treatment for my child. 

REFERENCES

1. Hu S, Meyer B, Duggal M. A silver renaissance in dentistry. Eur Arch Paediat Dent 2018; 19(4): 221-227.
2. Seifo N, Al-Yassen W, Innes N. The efficacy of silver diamine fluoride in arresting caries in children. Evid Based Dent 2018; 19(2): 42-43.
3. American Academy of Pediatric Dentistry (AAPD). Policy on the use of silver diamine fluoride for pediatric dental patients, 2018. 
4. American Academy of Pediatric Dentistry (AAPD). AAPD Clinical Practice Guidelines. Use of silver diamine fluoride for dental caries management in children and adolescents including those with special health care needs, 2017. 
5. Duangthip D, Fung MHT, Wong MCM, Chu CH, Lo ECM. Adverse effects of silver diamine fluoride treatment among preschool children. J Dent Res 2018; 97(4): 395-401. doi: 10.1177/0022034517746678.
6. Mei ML, Lo ECM, Chu CH. Arresting dentine caries with silver diamine fluoride: What’s behind it? J Dent Res 2018; 97(7): 751-758. doi: 10.1177/0022034518774783. 
7. Zhao IS, Gao SS, Hiraishi N, Burrow MF, Duangthip D, Mei ML, Lo EC, Chu CH. Mechanisms of silver diamine fluoride on arresting caries: a literature review. Int Dent J 2018; 68(2): 67-76. doi: 10.1111/idj.12320.
8. Sarvas, E. The history and use of silver diamine fluoride in dentistry: A review. 2018; CDA Journal 46(1): 19-22.
9. Patel J, Anthonappa RP, King NM. Evaluation of the staining potential of silver diamine fluoride: in vitro. Int J Paediatr Dent 2018; Jul 4.  doi: 10.1111/ipd.12401. 
10. Yee R, Holmgren C, Mulder J, Lama D, Walker D, van Palenstein Helderman W. Efficacy of silver diamine fluoride for arresting caries treatment. J Dent Res 2009; 88(7): 644-647.
11. Contreras V, Toro MJ, Encarnacion-Burgos MPL. Effectiveness of silver diamine fluoride in caries prevention and arrest: A systematic literature review. General Dentistry 2017; 65(3): 22-29.
12. Oliveira BH, Rajendra A, Veitz-Keenan A, Niederman R. The effect of silver diamine fluoride in preventing caries in the primary dentition: A systematic review and meta-analysis. Caries Res 2018; 53(1): 24-32.doi: 10.1159/000488686
13. Gordon NB. Silver diamine fluoride staining is acceptable for posterior primary teeth and is preferred over advanced pharmacologic behavior management by many parents. J Evid Based Dent Pract 2018, 18(1): 94-97.