Steps of SDF 38% application were carried out following the manufacturer's instructions. Eligible primary carious teeth were first dried and isolated using cotton rolls and gauze. Adjacent soft tissues were isolated using petrolleum gelly in order to prevent any irritation or staining from SDF that was directly placed into the carious lesion using a microbrush, allowed to absorb for 2 minutes, then dried with air. Parents were instructed that children should not eat for one hour after treatment. The second application was done after 6 months.

Pain reaction was assessed using the Sound, Eye, Motor scale (SEM) according to Wright et al. criteria. It is an objective method for pain assessment, where the child's level of anxiety was evaluated according to three types of observations. The score in each category ranged from one (no pain) to four (intense pain). A lower score represents less physical reaction to the procedure than does a higher value. Time of treatment was recorded using a stopwatch.

It was assessed using a 5-likert scale, self-administered questionnaire, specifically designed for the current study.