Condition category
Oral Health
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Dr Héctor Gatica Rossi


Contact details

Universidad de Chile
Facultad de Medicina
1027 Módulo F. 3º Piso

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Comparison of the effectiveness of fluoride varnish versus pit and fissure sealant for the prevention of caries in children of primary health care: randomised controlled clinical trial


Study hypothesis

The intervention of sealing pits and fissures of once a year application is more effective in reducing the incidence of caries when compared with application of fluoride varnish to 5% every six months, in children with an average age of 6 years for both sexes enrolled in schools in areas of low socioeconomic status and lower-middle of Santiago, Chile, considering clinically significant a reduction of 10% in the incidence of occlusal caries over a period of 12 months of follow-up.

Ethics approval

University of Chile Faculty of Medicine Ethics Committee of Investigation in Humans Beings approved on the 8th August 2008 (ref: 065-2008)

Study design

Interventional prospective randomised single-blind controlled multicentre clinical trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Occlusal caries


The choice of material to be used as a pit and fissure sealant in this project will be based on resin, since its use in primary care and is recommended by the Ministry of Health of Chile.

The sealant to be used in this study is the "Concise", manufacturer 3M, typically used in municipal health centers. The sealants should be given, taking into account the degree of eruption of first permanent molars, which is sufficient for proper application.

The procedure for applying a resin-based sealants must be sequenced according to the rules and recommendations established by the manufacturer. The staff that will be used to implement the experimental maneuver consists of dentists of Primary Health Care, which will be previously trained regarding the application of interventions. If during the execution of the study, a primary care dentist eventually shows little interest or fails to fulfill its tasks, he (or she) will be replaced by a dentist or a student of final year of odontology, previously trained.

The other intervention to be applied is the sodium fluoride varnish 5% (22,600 ppm. fluoride). This branch will be considered the control group. This material is indicated for the prevention of caries in occlusal surfaces of molars and pre molars and in smooth surfaces, and its application is recommended in all patients with moderate and high caries activity or cariogenic risk. The varnish used in this study is called "Duraphat to 5%", of the manufacturer Colgate.

The application is performed according to manufacturer's instructions. Human resources involved in the application of fluoride varnish is the same as the application of sealants. In this work, the varnish is applied, initially at the start of the investigation, and every 6 months, according to the recommendations established by national experts, until the end of the monitoring period, we will seek caries lesions in early stages of the process.

Due to the complexity of clinical trials, and the time at which the outcome is measured, it requires at least 24 months to implement the study. Students in this study will be followed by at least 1 year.

Intervention type



Not Applicable

Drug names

Primary outcome measures

Early stages of the process of occlusal caries in molars, prior to the formation of cavity with obvious dentine exposure, made on the basis of the criteria proposed by the International Caries Detection and Assessment System Coordinating Committee (ICDAS II).

All outcomes measured in July 2010.

Secondary outcome measures

1. Proportion of loss for the pit and fissure sealants in a period of 1 year follow up
2. Partial and total loss of pit and fissure sealants on the occlusal surface of permanent first molars, through visual examination

All outcomes measured in July 2010.

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Children of both sexes, 6 years old on average (or already in the process of eruption of first permanent molars)
2. Socio-economic levels belonging to medium-low or low status
3. Presenting at least one of the first permanent molars compatible with the application of materials, and free of clinically detectable caries (with exposed dentine) or fillings at the time of the beginning of the study
4. Who are willing to participate in the study, confirmed that by signing the informed consent letter for parents

Participant type


Age group




Target number of participants

193 students per group; total of 386 children

Participant exclusion criteria

Children that need some kind of special attention, as a procedure under general anaesthesia, presence of systemic disease or neurological limitations that impede their attention by a general dentist.

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Universidad de Chile

Sponsor information


Universidad de Chile (Chile)

Sponsor details

c/o Dr. Héctor Gatica Rossi
Facultad de Medicina
1027 Módulo F. 3º Piso

Sponsor type




Funder type


Funder name

National Commission for Science and Technology, Government of Chile (CONICYT) (Chile) - National Fund for Research and Development in Health (FONIS) (ref: SA08I20047)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes