What is Silver Diamine Fluoride and how does it work?

  • Silver Diamine Fluoride (SDF) is a clear liquid that contains silver and fluoride, which is stabilised in ammonia and is sold as RIVA star (38% SDF, 44,800ppm fluoride) in the UK.
  • It helps stop the progression of decay and reduces the risk of toothache or infection when painted onto primary teeth.
  • The kit should be stored in the fridge and comes with a silver capsule of SDF and a green capsule of potassium iodide.
  • The SDF can be used alone or in combination with the potassium iodide.
  • The SDF occludes dentinal tubules to stop dentine hypersensitivity, the silver is antibacterial, fluoride promotes remineralisation and SDF inhibits collagen degradation- all work together to promote caries arrest (there is good evidence to support its efficacy in primary teeth).
  • The Potassium Iodide aims to reduce staining- however, the evidence for this is conflicting with some suggesting that staining persists and its use can actually reduce the effectiveness  of SDF. Therefore, ensure you discuss all the risks prior to treatment and use this with caution.

What are the indications for using SDF?

  • Children with dental decay who can’t tolerate treatment under local anaesthetic (LA) and are likely to make positive changes to their oral hygiene and diet routine.
  • Patients where there is a need to delay dental treatment/ a long waiting list for treatment with inhalation sedation (RA) or general anaesthetic (GA)- this is particularly relevant due to the impact Covid-19 has had on RA and GA access and waiting lists.
  • Deciduous teeth which are asymptomatic and have cleansable, cavitated lesions into dentine and where other restorative options are not feasible.
  • As part of the acclimatisation process prior to carrying out definitive treatment.
  • In conjunction with the atraumatic restorative technique.

What are the contraindications for using SDF?

  • An allergy to Silver, other heavy metals or other components of SDF.
  • Sores/ulcers in the mouth or painful gums.
  • Signs of infection/irreversible pulpitis, caries to the pulp- clinically or radiographically.
  • Food packing.
  • Patients undergoing thyroid gland therapy or on thyroid meds- only relevant if potassium iodide is used.

Advantages of SDF?

  • Simple procedure.
  • Reduces sensitivity and slows down/stops tooth decay.
  • More effective than fluoride varnish.
  • Good evidence to support caries arrest.
  • Can buy time for patients who cannot tolerate treatment under LA currently.

Disadvantages of SDF?

  • Permanently discolours decayed areas of teeth black and will stain clothes (healthy teeth will not get stained).
  • Temporarily discolours soft tissues brown or white for 1-3 weeks.
  • Can discolour tooth coloured fillings- sometimes polishing can help this, but sometimes staining will still be present at the margins.
  • Requires monitoring.
  • Not as cheap as topical fluoride- 12 applications of SDI Riva Star is £79.20.
  • Rarely it can cause a chemical burn to the gingiva.
Silver Diamine Fluoride - Before and After
Silver Diamine Fluoride – Before and After

Discussions about SDF to have with parents/patients

  • WHO recommends SDF as a caries management option if co-operation is limited.
  • But, alternative treatment options are to keep the decayed teeth under review (it’s likely the decay will get worse), fluoride varnish and review (it’s likely the decay will get worse), restore the tooth with conventional restorations or Hall Crown or extract the tooth (requires good patient co-operation).
  • SDF isn’t licensed for decay in the UK (currently only licensed for sensitivity), but it is fully licensed in many other countries and has been used safely to treat decay for years. Recently it has been widely recommended in the UK to be used for treating decay.
  • If the decay continues to progress, other treatment may be required- fillings or tooth removal etc.
  • Essential to maintain good oral hygiene and a low sugar diet to stop decay progressing or affecting other teeth.
  • Need to make sure that parents understand that teeth will be stained darker-it is recommended that you sign a consent form and give parents an information leaflet and time to consider this treatment before carrying it out.

How do you use SDF?


  • Ensure ID checked, valid consent obtained and PPE worn.
  • If indicated, take pre-op photos and radiographs.

Clinical procedure:

  • Use one capsule per patient and pierce the foil with a micro brush.
  • Place petroleum jelly on the lips and gums with a cotton wool roll (RIVA star comes with barrier gel that is light cured and can be used on the gingiva as an alternative).
  • Ensure teeth are clean and free of debris- you can remove soft caries with an excavator.
  • Cotton wool rolls are placed next to the teeth and the area to be painted should be dried with gauze, cotton wool rolls or a 3-in-1.
  • Paint the SDF liquid onto the caries and leave to soak for 1-3 minutes.
  • Then dry the teeth again with gauze, cotton wool roll or a clean micro brush.
  • If using Potassium Iodide, apply to treatment site with a clean micro brush.
  • You can then either leave the tooth, paint fluoride over this or restore the tooth.
  • Remove gingival barrier if used.
  • Toothpaste can be placed on the tongue prior to treatment to mask the metallic taste of SDF.

Follow up:

  • Follow patient up at 2-4 weeks – check for caries arrest (hardened tooth tissue) and re-apply SDF if needed.
  • 3-6 month recall based on risk assessment – reapply 6 monthly or alternatively restore if possible.


  • SDF is a great option to try and arrest caries in patients who are pre co-operative, but remember definitive restorations/treatments are always preferable if possible.
  • Ensure you gain valid consent and warn patients/parents of the permanent staining to teeth.
  • Positive changes to diet and oral hygiene are essential for SDF to be effective.

References and recommended reading

1. BSPD. (2020). Children and Laura the dentist explain all about Silver Diamine Fluoride. Available: https://www.youtube.com/watch?v=qHz8CT_rNMM&feature=emb_title. Last accessed 31st Jan 2021.
2. BSPD. (2020). How to apply silver diamine fluoride. Available: https://www.youtube.com/watch?v=tELmH9jRvv8. Last accessed 31st Jan 2021
3. BSPD. (2020). SDF resources. Available: https://www.bspd.co.uk/Professionals/Resources. Last accessed 31th Jan 2021.
4. Chibinski, A et al. (2019). Silver Diamine Fluoride for managing carious lessons: an umbrella review. BMC Oral health. 19, 145.

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Dental Officer, BDS (Hons). I’ve got MFDS with Edinburgh, PGCert in Medical Education and HEA accreditation.


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