Prevention of pit and fissure caries using an antimicrobial varnish: 9 month clinical evaluation

The purpose of this study was to determine whether Cervitec--a chlorhexidine--containing varnish could reduce the development of pit and fissure caries in children.

One hundred children each in age groups 7-8 and 12-14 years were selected from schools in Riyadh, Saudi Arabia. To be included in the study, each child had to have at least two sound contra-lateral first or second permanent molars with deep fissures. A split mouth method was used with one test tooth and one control within the same jaw. The left or the right side was selected randomly for test or control. The plaque samples from the occlusal surfaces of the test and control and the saliva samples were collected at baseline examination and after 9 months to estimate the number of Streptococcus mutans by the strip mutans method of Jensen and Bratthall (Jensen B, Bratthall D. A new method for the estimation of mutans streptococci in human saliva. Journal of Dental Research 1989;68:468-471). Cervitec varnish containing 1% chlorhexidine (CHx) and thymol was applied at baseline, at 3-4 months and at 6 months to the test tooth after isolation while the control had prophylaxis using cotton pellet in water each time the varnish was applied to the test tooth. Caries examination of the test and control followed after 9 months, according to the criteria and methods of WHO (World Health Organization. Oral Health Surveys. Basic Methods 4th ed., Geneva, WHO 1997). The blind technique was used in the diagnosis of caries and in the examination of the S. mutans count at the end of the study.

Ninety four of the 7-8 year old and 86 of the 12-14 year old children completed the study. The results showed that the caries increment in both control groups of teeth after 9 months is significantly higher than in the test teeth (McNemar test: chi2 = 11.60, P < 0.001). The rate of caries development in a fissure was significantly correlated to the plaque mutans score of that fissure and there was considerable reduction in the S. mutans count of the plaque in the test teeth compared with the control (Spearman Rank Correlation: P < 0.001).

It is concluded that the CHx varnish reduced the development of fissure caries significantly.