Fissure sealants have been used in pediatric dentistry since 1960s to prevent dental caries, particularly in primary and permanent posterior teeth. They are recommended for individuals at high risk for caries, those with multiple carious lesions, and those with deep, narrow pits and fissures. Resin-based sealants are common and used with phosphoric acid for etching, but they require good moisture control to be effective. Numerous newer sealant materials have been developed since the first dental sealant, Nuva Seal, was introduced in 1971.

The resin-based sealant technology has also advanced to include a moisture tolerant chemistry. Traditional sealants are hydrophobic and the major drawback of these sealants is sensitivity to moisture, which ultimately leads to failure in the retention of the sealant. This occurs because the tooth to be sealed are partially erupted which precludes them to be properly isolated. Newer moisture-tolerant sealants are hydrophilic, allowing them to create a strong bond for better retention in moist conditions, making them ideal for children. Though there are numerous studies on the retention of different sealant materials, there are only very limited studies on the retention and evidence of caries after hydrophilic sealant placement in primary molars. So, the aim of my study is to clinically evaluate the retention of hydrophilic sealant against hydrophobic sealant.