Effectiveness of fissure sealants on initial caries lesions (ICDAS 1-3) of permanent molars: A 4-year follow-up.

Aim: The aim of the present prospective study was to evaluate the retention and effectiveness of two types of sealants (clear vs. opaque) on early pit and fissure occlusal non-cavitated ICDAS II #1-3, caries lesions of permanent posterior teeth of children.

Materials And Methods: Study Design: 6986 pit and fissure occlusal surfaces were randomly sealed with clear or opaque sealants out of which, 5828 sealants were placed on sound and 1158 on questionable surfaces, while 3508 were clear and 3478 opaque sealants. The mean age of the sample at initial sealant placement was 9.5 (±2.9) years and the follow-up time was 12-48 months. The median (IQR, range) follow-up time was 17.9 (8.7-28.6) months. Study inclusion and exclusion criteria applied to the combined database in order to select the study sample. Teethmate™ F-1 natural and opaque sealants (Kuraray, Hattersheim am Main, Germany) were applied following the standard procedure of preparation with moisture control kept by cotton rolls handled Dri-Angles" and a 30 seconds acid-etch with 37% ortho-phosphoric acid gel was used followed by 10 sec air-water spraying washing and polymerization for 20x2 sec. Sealants were applied on sound tooth surfaces (ICDAS #0) with no visible defects or on surfaces with early caries lesions (ICDAS #1-3), randomly and interchangeably on the upper or lower Jaw. Total retention was considered when all pits and fissures were completely sealed, while partial or complete loss was scored as one code, although was registered separately.

Statistics: Separate analyses were performed for each type of failure (loss of sealant or restoration). Cumulative probabilities of failure over time after sealant placement, overall or by specific characteristics, were calculated using the Kaplan-Meier method. Association between these characteristics and the hazard of failure were investigated using appropriate Cox proportional hazard models.

Results: Sealed surfaces with ICDAS II # 1-3, showed 100% higher probability of having a restoration and 60% higher probability of sealant loss, with both differences being statistically significant (aHR=2.03, p=0.046), adjusted for age, sex, type of sealant and location of surface. Opaque sealants presented statistically significant (p 0.009) higher re-application rate, while fissures had 70% statistically significant (p<0.001) higher probability for resealing with time compared to pits, with gender not affecting sealant retention while the earlier a sealant was placed on children's teeth, the more probable it was to need resealing or restoration (p <0.012).

Conclusions: The therapeutic use of sealants on occlusal surfaces of posterior permanent molars with early carious lesions (ICDAS II 1-3) is inferior compared to sound surfaces, showing higher sealant failures and restorations.