Introduction: Dental caries constitutes a major oral health problem at a global scale for the elderly population. It impacts the health system due to its high incidence and prevalence and its associated costs. The growing population of elderly experiencing a loss of autonomy is accompanied by a decline in motor functions, which affects their ability to carry out everyday tasks such as brushing their teeth. The resulting poor oral hygiene can contribute to the onset of oral diseases. Dental caries can significantly impact the quality of life of the elderly by provoking pain, chewing difficulties, tooth loss and malnutrition. Recently, Silver Diamine Fluoride (SDF) 38% has been introduced to the market as an efficient solution for promoting oral health and arresting active caries. SDF is a compound of silver, fluoride, and ammonia, which comes in the form of a bluish liquid and is applied in small amounts on active carious lesions. Despite its recent approval by Health Canada as a temporary solution for arresting active caries, few randomized controlled trials have evaluated its effectiveness on the institutionalized elderly.

Objectives: This pilot study aims to evaluate the impact of SDF on the oral health of the elderly living in long-term care facilities.

Principal objective: evaluate effectiveness of SDF on arrestation of active caries when applied for the elderly with loss of autonomy in long-term care facilities.

Secondary objectives:

1. evaluate the relationship between SDF application and caries activity
2. Analysis of salivary biomarkers involved in the associated inflammatory processes.

Methodology: A randomized controlled feasibility and effectiveness study design will be employed. This study will span over 12 months and will include 3 data collection phases.

At T0 (baseline): SDF group participants will receive an SDF application on their active caries. Control group participants will receive a 0.9% saline solution (placebo) application.

AT T1, 6 months after T0: First phase of data collection, the two groups will receive SDF application.

At T2, 12 months after T0: second phase of data collection, and for ethical reasons, the control group, who received placebo at T0, will receive an SDF application.

At the end of the project, a fluoride varnish application will be carried out on both groups to prolong preventive effects of treatment. A short questionnaire will also be shared with participants to evaluate their satisfaction and identify unintended adverse effects.

Anticipated results:

Demonstrate the efficiency of SDF in controlling active caries in the elderly with autonomy loss.

Elaborate a clinical protocol for SDF application in long-term care facilities Establish the required sample size for a future bigger study.

Inclusion Criteria:

• Elderly of 65 years of age or older living at a long-term care facility targeted by the study.
• Should present at least one coronal or radicular active carious lesion that is asymptomatic, untreated, or a residual lesion under a restoration, and without pulp involvement.

Exclusion Criteria:

• Participants with inadequate collaboration that may impede dental examination or treatment.
• Participants with cardiac valve prostheses, a history of bacterial endocarditis, or valve disease following a heart transplant.
• Completely edentulous elderly, as well as elderly presenting with no coronal or radicular caries
• Participants allergic to silver, fluoride or ammonia.

The statistician will be masked as well. The expert calibrating the dentists will also be masked