Dissertation defence (Cariology and Restorative Dentistry): DDS Merve Üçtaşlı
DDS Merve Üçtaşlı defends the dissertation in Cariology and Restorative Dentistry titled “From Biology to Mechanics: Effects of Silver Fluoride Treatments on Dentin” at the University of Turku on 15 May 2026 at 12.00 (University of Turku, Dentalia, Arje Scheinin lecture hall, Lemminkäisenkatu 2, Turku).
Opponent: Professor Milena Cadenaro (University of Trieste, Italy)
Custos: Professor Arzu Tezvergil-Mutluay (University of Turku)
Summary of the Doctoral Dissertation:
According to the World Health Organization, untreated tooth decay affects 2.5 billion people worldwide, making it the most common yet largely preventable noncommunicable disease. Despite advances in modern dentistry, dental caries continues to impact daily life, causing pain, tooth loss and a growing need for treatment.
In recent years, silver fluoride-based treatments have gained global clinical and research attention as a simple, non-invasive approach to stop tooth decay, either without drilling or with minimally invasive dentistry. These treatments are increasingly used, especially among children, older adults, patients at high risk for tooth decay and individuals with disabilities. However, although their clinical effectiveness has been demonstrated, much less is known about how these materials affect the tooth itself over time and about their underlying mechanisms.
This doctoral dissertation investigated how silver fluoride-based treatments interact with dentin, the inner tissue that gives teeth their strength. The research focused on two commercially available materials: ammonia-based silver diamine fluoride (SDF) and water-based silver fluoride (SF). The study also examined the effects of potassium iodide (KI), which is often applied after silver fluoride treatments to reduce dark tooth staining.
The key findings show that both SDF and SF slow down enzymes inside dentin that gradually weaken tooth structure. By protecting the tooth’s internal collagen, these materials can help preserve dentin and support long lasting dental care. Importantly, clear differences were found between the materials. SF showed better biocompatibility and improved the ability of decayed dentin to withstand repeated chewing forces compared with SDF.
The research also revealed that KI, although helpful for improving aesthetics, was associated with less favorable outcomes, including greater internal tissue breakdown, higher cellular toxicity and weaker mechanical performance. In addition, the study showed that small changes in clinical procedures, such as rinsing the tooth or delaying the placement of a filling, can improve bonding to teeth after silver fluoride-based treatments.
Overall, this research provides new insight into how silver fluoride-based treatments affect both the biology and mechanics of teeth. The findings suggest that silver fluoride treatments, particularly when used without KI in situations where appearance is not the primary concern, may offer a safer and more durable treatment option. These results support long lasting approaches to dental care and help clinicians make decisions for patients around the world.
