The effect of MI Varnish™ on the development of tooth decay in 6- and 12-year-old children in Riga, Latvia

Plain English Summary

Background and study aims
Tooth decay (dental caries) is damage to a tooth that can happen when decay-causing bacteria in your mouth make acids that attack the tooth's surface, or enamel. This can lead to a small hole in a tooth, called a cavity. If tooth decay is not treated, it can cause pain, infection, and even tooth loss.
Fluoride varnish (FV) is considered safe, well accepted by children, and easily delivered by health practitioners. A therapeutic product combining fluoride and CPP-ACP in a varnish (MI Varnish™; GC corporation, Japan) was developed few years ago demonstrating its caries prevention potential.
The aim of the present study was to investigate the effect of MI Varnish™ on caries increment in 6- and 12-year old children in Riga, Latvia within 36 months.

Who can participate?
6- and 12-year old children, inhabitants of Riga, who visited the Institute for dental treatment.

What does the study involve?
All children were recruited into the study during their regular dental check-ups in a random manner. On meeting the examiner, odd numbers of both age groups were recruited into the Varnish group (6 years old into group 1; 12 years old into group 3), while even numbers were recruited into the control groups (6 years old into group 2; 12 years old into group 4).
Following the baseline caries examination, the treatment groups (group 1 & 3) received the application of MI Varnish™ (5% sodium fluoride GC Corp., Tokyo, Japan), while the control groups (Group 2 & 4) did not have varnish applied.
Groups 1 & 3 had the varnish applied every 3 months for 3 years.
All subjects received general oral hygiene instruction at baseline and at the last visit.

What are the possible benefits and risks of participating?
Benefits: Participants will receive more frequent checkups for dental caries.
Risks: None

Where is the study run from?
Riga Stradins University (Latvia)

When is the study starting and how long is it expected to run for?
December 2015 to March 2020

Who is funding the study?
Investigator initiated and funded

Who is the main contact?
Dr Jekaterina Gudkina, jekaterina.gudkina@rsu.lv

Study website

Type

Scientific

Contact name

Dr Jekaterina Gudkina

ORCID ID

http://orcid.org/0000-0001-5135-1538

Contact details

20 Dzirciema street
Riga
LV-1010
Latvia
+371 29486408
jekaterina.gudkina@rsu.lv

EudraCT/CTIS number

Nil known

IRAS number

ClinicalTrials.gov number

Nil known

Protocol/serial number

U1111-1275-4126

Scientific title

The effect of MI Varnish™ on dental caries among 6- and 12-year-old children in Riga, Latvia. A 3-year study.

Acronym

Study hypothesis

Quarterly application of MI Varnish™ could reduce caries increment in children in Riga, Latvia.

Ethics approval(s)

Approved 17/12/2015, RSU Ethics Committee (16 Dzirciema str., Riga, Latvia; +371 67326203; pek@rsu.lv), ref: not provided

Study design

Single-center interventional randomized controlled trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Study setting(s)

Dental clinic, University/medical school/dental school

Study type

Prevention

Patient information sheet

See additional files

Condition

Dental caries development

Intervention

Current interventions, as of 04/04/2022:

All children were recruited into the study during their regular dental check-ups in a random manner as follows. During the visit, children are listed in serial numbers in the order of their arrival time at the reception desk of the RSU Institute of Stomatology. On meeting the examiner, odd numbers of both age groups were recruited into the Varnish group (6 years old into group 1; 12 years old into group 3), while even numbers were recruited into the control groups (6 years old into group 2; 12 years old into group 4).

Following the baseline caries examination, the treatment groups (groups 1 & 3) received the application of MI Varnish™ (5% sodium fluoride GC Corp., Tokyo, Japan), while the control groups (Group 2 & 4) did not have varnish applied. Application of MI varnish was performed in accordance with the manufacturer’s instruction. The post-varnish instruction as provided by the manufacturer was given to all children and their parents. Neither the children nor their parents in the Varnish (Groups 1 and 3) were informed about the name of varnish (MI Varnish) used, and the manufacturer’s name.

Subsequently, subjects in the treatment groups (group 1 & 3) were recalled every 3 months for re-application of varnish for the 36 months study period. Subjects in the control groups (Group 2 & 4) again received only oral hygiene instruction. Children and their parents were informed about the precise time of attending the dentist by using the mobile telephone number provided at a baseline. At the baseline and 3 monthly MI Varnish re-application visits, teeth were brushed with non-fluoridated professional toothpaste (Zircate Prophy Paste; Dentsply Caulk, Germany) and then MI Varnish™ (GC Corp., Tokyo, Japan) was reapplied on all tooth surfaces.

_____

Previous interventions:

All children were recruited into the study during their regular dental check-ups in a random manner as follows. During the visit, children are listed in serial numbers in the order of their arrival time at the reception desk of the RSU Institute of Stomatology. On meeting the examiner, odd numbers of both age groups were recruited into the Varnish group (6 years old into group 1; 12 years old into group 3), while even numbers were recruited into the control groups (6 years old into group 2; 12 years old into group 4).

Following the baseline caries examination, the treatment groups (groups 1 & 3) received the application of MI Varnish™ (5% sodium fluoride GC Corp., Tokyo, Japan), while the control groups (Group 2 & 4) did not have varnish applied. Application of MI varnish was performed in accordance with the manufacturer’s instruction. The post-varnish instruction as provided by the manufacturer was given to all children and their parents. Neither the children nor their parents in the Varnish (Groups 1 and 3) were informed about the name of varnish (MI Varnish) used, and the manufacturer’s name.

Subsequently, subjects in the treatment groups (group 1 & 3) were recalled every 3 months for re-application of varnish and reinforcement of the oral hygiene instructions for the 36 months study period. Subjects in the control groups (Group 2 & 4) again received only oral hygiene instruction. Children and their parents were informed about the precise time of attending the dentist by using the mobile telephone number provided at a baseline. At the baseline and 3 monthly MI Varnish re-application visits, teeth were brushed with non-fluoridated professional toothpaste (Zircate Prophy Paste; Dentsply Caulk, Germany) and then MI Varnish™ (GC Corp., Tokyo, Japan) was reapplied on all tooth surfaces.

Intervention type

Other

Primary outcome measure

Current primary outcome measure as of 04/04/2022:

Measured at baseline and 36 months:
1. Caries increment measured using the caries assessment criteria of the ICDAS II (https://www.iccms-web.com)
2. Oral hygiene indices measured using the Green-Vermillion oral hygiene index (G-V index)
3. Dietary habits measured using a questionnaire for children and/or their parents about snacking habit, intake of chocolates, carbonated soft or sport drinks during the day, number of tea spoons of sugar (t.s.) per cup of tea, and the number of cups of tea consumed daily

_____

Previous primary outcome measure:

Measured at baseline and every 3 months for 36 months:
1. Caries increment measured using the caries assessment criteria of the ICDAS II and digital bitewing (BW) X-rays
2. Oral hygiene indices measured using the Green-Vermillion oral hygiene index (G-V index)
3. Dietary habits measured using a questionnaire for children and/or their parents about snacking habit, intake of chocolates, carbonated soft or sport drinks during the day, number of tea spoons of sugar (t.s.) per cup of tea, and the number of cups of tea consumed daily

Secondary outcome measures

There are no secondary outcome measures

Overall study start date

17/12/2015

Overall study end date

13/03/2020

Reason abandoned (if study stopped)

Participant inclusion criteria

Healthy volunteers at the age of 6 and 12 years, living in Riga.

Participant type(s)

Healthy volunteer

Age group

Child

Lower age limit

6 Years

Upper age limit

12 Years

Sex

Both

Target number of participants

A total number of 64 children per group has been estimated to detect a difference between groups, with a two-tailed α of 0.05 and a (1-β) of 0.80, for a comparison of 2 independent means if there was an absolute difference of 5 units outcome measure and standard deviation of 9 units. The drop out was calculated as 25%. Sample size was calculated as follows: Type I error = 5% implies constant 1,96 Type 2 error = 20% implies constant 0,84 N=2*[((1,96+0,84)*SD)/(difference)]2 = 2*(2,8*9/5)2=50,8032~51 N(with drop-out)=1,25* 51 = 63,75 ~ 64 children per each group.

Total final enrolment

260

Participant exclusion criteria

1. Children and/or their parents refused to participate in the study
2. The families moved away from Riga
3. Children or parents did not answer the 3 telephone calls confirming their appointments
4. Orthodontic braces
5. General ill-health within the study period

Recruitment start date

01/02/2016

Recruitment end date

12/03/2017

Countries of recruitment

Latvia

Study participating centre

RSU Institue of Stomatology
20, Dzirciema street
Riga
LV-1010
Latvia

Organisation

Riga Stradiņš University

Sponsor details

16 Dzirciema street
Riga
LV-1010
Latvia
+371 60002571
tsk@rsu.lv

Sponsor type

University/education

Website

http://www.rsu.lv/eng/

ROR

https://ror.org/03nadks56

Funder type

Other

Funder name

Investigator initiated and funded

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Publication and dissemination plan

Planned publication in a high-impact peer-reviewed journal.

Intention to publish date

31/12/2022

Individual participant data (IPD) sharing plan

The datasets generated during and analyzed during the current study will be available upon request from Dr Jekaterina Gudkina (j.gudkina@inbox.lv).

IPD sharing plan summary

Available on request

Study outputs

• 41306 Protocol.pdf
• 41306 PIS control group.pdf control group
• 41306 PIS intervention group.pdf intervention group