Please assess the completion status of the following clinical trial:

Trial Title: Preventing and Arresting Dental Root Surface Caries in Community-dwelling Older Adults

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: PREVENTION
- Time Perspective: None
- Masking: DOUBLE
- Phase: PHASE2/PHASE3
- Number of Arms: 3.0

Eligibility Criteria:
Inclusion criteria:~* have at least 5 teeth with exposed root surfaces and not indicated for extraction, and~* living in the community and have self-care ability for normal daily activities.~Exclusion Criteria:~* have life-threatening or serious health problems,~* have cognitive problems in communication or in receiving oral hygiene instructions~* have salivary gland diseases or received radiotherapy in the head and neck region.

- Gender: ALL
- Minimum Age: 56 Years
- Maximum Age: 85 Years
- Healthy Volunteers: t

Study Arms:
- control (Type: PLACEBO_COMPARATOR): instructions on oral hygiene (OHI) tailored to the individual's condition will be given, and a tube of toothpaste containing 1,000 ppm fluoride (the most popular type of adult toothpaste in the Hong Kong market) will be provided. The OHI and provision of toothpaste will be repeated at 6-month intervals. In addition, distilled water as placebo with a bitter flavor added (to mimic the bitter metallic taste of SDF) will be painted onto all exposed tooth root surfaces using a small disposable brush. This procedure will be repeated after 12 and 24 months.
- silver diammine fluoride (Type: EXPERIMENTAL): the subjects will receive the same intervention as those provided to subjects in the control group except that a 38% SDF solution (Saforide, Toyo Seiyaku Kasei Co. Ltd, Osaka, Japan) instead of the placebo solution will be painted onto the exposed tooth root surfaces. This treatment will be repeated after 12 and 24 months.
- silver diammine fluoride and KI (Type: ACTIVE_COMPARATOR): the subjects will receive the same treatment as those provided to subjects in the control group except that a 38% SDF solution instead of the placebo solution will be painted onto the exposed tooth root surfaces and followed by painting of a saturated potassium iodide solution. This treatment will be repeated after 12 and 24 months.

Based on this trial design, predict the completion outcome and termination type (if applicable).