Clinical trial NCT02742142: Fluoride Application on Preventing and Arresting Root Caries in Fluoridated and Non-fluoridated Areas
Official title: Randomized Clinical Trial on Preventing and Arresting Root Surface Caries Using Silver Diammine Fluoride Solution in Older Adults Living in Fluoridated and Non-fluoridated Areas
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
PHASE3
Conditions: Dental Caries
Lead sponsor: The University of Hong Kong
Sponsor class: OTHER
Collaborators: name: Sun Yat-sen University
First posted: 2016-04-18
Enrollment: 534
Sex: ALL
Minimum age (years): 55
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: This study was a randomized clinical trial lasting for 24 months in two study sites, Hong Kong (water fluoridated) and Guangzhou (non-fluoridated area). A total of 534 subjects will be recruited from elderly social centers located in different districts in the two study sites (260 \& 274). Baseline clinical examination was conducted by a single calibrated examiner in the social centers using an intra-oral LED light, mouth mirrors and probes. Subjects were randomly allocated into two study groups and receive interventions accordingly. Follow-up examinations at 6-month intervals were carried out to assess the clinical outcomes, i.e. whether new root caries developed and whether the active root caries found at baseline become arrested. Results of this study could provide the much needed evidence to guide the dental professionals in Hong Kong and China, and possibly worldwide in deciding on the most appropriate intervention for the prevention and management of this common dental disease of the older adults.

Detailed description: The primary and secondary outcome of this study was new root caries and arrested root caries. A root surface with new caries experience was recorded when a root surface which was sound at baseline was found to have a carious lesion or a filling at a follow-up examination. Arrested root caries was recorded when the active root caries found at baseline changed into inactive root caries at follow-up. The status of each root surface was recorded using the codes recommended by the International Caries Detection and Assessment System (ICDAS Ⅱ) Coordinating Committee in 2009.

A mean root caries increment of around 0.8 root surface per year of control group was reported in a previous clinical trial conducted in Hong Kong. Thus, in this study, a 24-month increment of 1.6 new decayed root surfaces and a standard deviation of 2 was anticipated. In order to show that a 50% difference in mean caries increment between the test and control groups was statistically significant using a 2-sample t-test at a 5% significance level and at an 80% power, a sample size of 100 subjects in each group was required. Allowing for a drop-out rate of 20% over 24 months, a total of 480 subjects (120 in each group each site) were needed.

Eligibility criteria: Inclusion Criteria:

1. have at least 5 teeth with exposed root surfaces and not indicated for extraction, and
2. living in the community and have self-care ability for normal daily activities.

Exclusion Criteria:

1. have life-threatening or serious health problems,
2. have cognitive problems in communication or in receiving oral hygiene instructions
3. have salivary gland diseases or received radiotherapy in the head and neck region.

Primary outcomes:
measure: Tooth Root Caries Lesions
timeFrame: 24 months
Secondary outcomes:
measure: Arrested root caries lesions
timeFrame: 24 months
Other outcomes:
Locations:
city: Guangzhou
country: China
facility: Sun Yat-sen University
state: Guangdong
city: Hong Kong
country: China
facility: The University of Hong Kong
Study officials:
affiliation: The University of Hong Kong
name: Edward CM Lo, BDS, PhD
role: PRINCIPAL_INVESTIGATOR
References: