Microhardness and Bacterial Inhibitory Effect of Riva Star versus Silver Diamine Fluoride on Carious Dentin of Primary Teeth (In-vitro study).

Document Type : Original Article


1 Pediatric Dentistry and Dental Public Health Department, Faculty of Dentistry, Cairo University, Egypt

2 Medical Microbiology and Immunology Department, Faculty of Medicine, Cairo University, Cairo, Egypt


Aim: The aim of this study was to measure the microhardness and the antibacterial effect of Riva star on carious dentin of primary teeth versus those treated with SDF only. Methods: For microhardness testing: Thirty freshly extracted primary molars were collected. Occlusal enamel and soft carious dentin were removed. The teeth were randomly allocated to control (SDF) or intervention group (Riva star). Vicker’s microhardness was measured at baseline and after treatment. For inhibition zone measurement: The standard strain of Streptococcus mutans was used to test the antibacterial effect. Four wells were incorporated with Riva Star, SDF, chlorhexidine and distilled water. The zones of inhibition were measured in millimeters in diameter around the material after 24 h. Results: Microhardness test: There was no statistically significant difference at baseline between (Riva Star) and (SDF) groups (p=0.050). After treatment, there was a statistically significant difference between (Riva Star) and (SDF) groups (p<0.001). Inhibition zone measurement: A statistically significant difference was found between (Distilled water) and each of (Riva Star), (SDF) and (Chlorhexidine) groups (p<0.001). Conclusions: SDF and Riva star both resulted in increased microhardness of carious dentin of primary teeth. SDF/KI had a relatively lower antibacterial effect in comparison with SDF alone.