Clinical Assessment of Root Caries Treatment Based on the Discoloration of Silver Diamine Fluoride as a Caries Indicator

抄録

 Purpose: This clinical study aimed to evaluate whether changes were observed in saliva test outcomes before and after application of 38% silver diamine fluoride (SDF) in elderly patients with root caries lesions. Following this, the root caries discolored by SDF was restored to verify SDF as a potential caries indicator for the removal of carious tissue on root surfaces.

 Methods: This study was approved by the Research Ethics Committee of Asahi University, School of Dentistry (Approval Number: 32031). Twenty elderly patients with root caries visiting the Operative Dentistry Clinic of Asahi University Medical and Dental Center between March 2021 to March 2022 were recruited. The caries risk of these patients was evaluated using a saliva test kit (Salivary Multi Tests; SMT) before and after SDF application (at the first and the second visits). The values of SMT measurement before and after SDF application were analyzed for six items: cariogenic bacterial count, saliva acidity, buffering capacity, leukocytes, protein, and ammonia. Caries removal was guided by the staining from SDF as a caries indicator using an excavator, then a resin composite restoration was placed. Each clinical procedure was photographed.

 Results: There were 20 participants: 15 males and 5 females (mean age 76.5 years). The total number of teeth with root caries lesions was 90 (51 incisors, 23 premolars, and 16 molars). There were no significant differences in the SMT results before and after the SDF application (p＞0.05). However, the coefficient of variation values before and after SDF application tended to be different among the evaluated items. The coefficient of variation was 1.97 for caries-causing bacteria, while it ranged from 0.26 to 0.69 for the other items. From the photographs of the clinical cases, application of SDF discolored and arrested the root caries lesions. This led to a reduction in bacterial adherence as well as gingival inflammation. The resin composite restorations for the teeth with root caries lesions were deemed successful during the observation period (max. 10 months).

 Conclusion: No significant difference was found in each item of SMT measurement before and after the application of SDF. However, the bacterial count exhibited a significant variation, suggesting suppression of the bacterial adherence on the root caries lesion by the application of SDF. SDF application could be used as a favorable indicator for diagnosis and excavation of carious root tissue when a restoration is required.