Comparative Evaluation of Hydrophilic and Hydrophobic Sealants in Partially Erupted First Molars

This is a randomized controlled clinical trial designed to evaluate and compare the effectiveness of three types of pit and fissure sealants-hydrophilic (Embrace WetBond), nanofilled hydrophobic (DENU Seal), and conventional hydrophobic (Helioseal F)-when applied to partially erupted first permanent molars in children aged 5 to 7 years. The study aims to assess the sealants' clinical retention, their ability to prevent dental caries, microleakage, sealant penetration depth, and fluoride release.

A total of 150 children will be randomly assigned to three equal groups of 50 participants each. A split-mouth design will be used: in each group, sealants will be applied with and without bonding agents on opposite sides of the upper or lower arch, allowing intra-subject comparisons. Clinical evaluations will be conducted at 3, 6, 12, and 18 months to assess sealant retention and caries incidence using the modified Color, Coverage, Caries (CCC) Sealant Evaluation System.

In addition to the clinical phase, a laboratory phase will be conducted using extracted human premolars. This phase will evaluate microleakage and sealant penetration under a stereomicroscope following dye penetration techniques. Fluoride release will be measured at specified time intervals (1, 7, 14, 21, and 28 days) using an ion-selective electrode in artificial saliva conditions maintained at 37°C.

The primary outcomes include sealant retention and caries incidence. Secondary outcomes focus on the degree of microleakage, sealant penetration, and fluoride release. The trial will help determine whether moisture-tolerant sealants offer superior clinical and preventive benefits over traditional hydrophobic materials, particularly in situations where ideal isolation is difficult, such as with partially erupted teeth in young children.

The study will be conducted at the Pediatric Dentistry Clinic, Faculty of Dentistry, Mansoura University, and is expected to generate evidence that could improve clinical decision-making in preventive pediatric dentistry.

• Prevention (Other), also known as Helioseal-F plus: Conventional Hydrophobic Sealant (Helioseal F - Control) will be used as a positive control; applied to partially erupted molars with and without bonding in a split-mouth design.
• Prevention of caries (Other), also known as Hydrophilic Embrace-Wetbond: Embrace WetBond sealant will be applied to partially erupted first permanent molars using a split-mouth design with and without bonding agent.
• Prevention therapy (Other), also known as Denuseal: DENU Seal applied using a split-mouth design to evaluate bonding and non-bonding application outcomes from retention and caries prevention

Primary outcomes

• Retention [18 months]: retention is evaluated using CCC Index (Color, Coverage, and Caries) This scale is used to assess sealant retention and caries status during follow-up evaluations. Score Description Retention Caries Status Interpretation 0 Sealant completely retained no caries Full retention Best outcome 1. Partial sealant loss no caries Partial loss Acceptable 2. Sealant completely lost no caries Total loss Less ideal 3. Sealant partially or totally lost caries present Partial or total loss Worst outcome
• Caries [18 months]: Caries Incidence: 3, 6, 12, 18 months, t each recall (3, 6, 12 months), evaluate each sealed tooth using the CCC score: If the sealant is completely intact and no caries is visible → score = 0 If the sealant is partially gone but no decay → score = 1 If sealant is lost but still no decay → score = 2 If sealant is lost/partial and there is decay → score = 3

Secondary outcomes

• Microleakage [3 months]: Microleakage Assessment (lab) - dye penetration . Score Description Microleakage Depth Interpretation 0 No dye penetration 0% of fissure depth Best outcome 1. Dye penetrates into enamel only <50% of enamel Good 2. Dye penetrates to dentino-enamel junction (DEJ) Reaches DEJ, no dentin Borderline 3. Dye penetrates into dentin Past DEJ into dentin Worst outcome Minimum score: 0 = no leakage Maximum score: 3 = extensive leakage Higher score = worse outcome
• Fluoride release [2months]: Fluoride Release - spectrophotometer (1, 7, 14, 21, 28 days) Fluoride Release Scoring System (Modified Scale for Clinical Correlation) Because fluoride release is continuous and measured in ppm or µg/cm²/day, we can categorize release levels into scores for easier interpretation. Score Fluoride Release Level Typical Range Interpretation 0 High, sustained release >2 ppm after 1 week Best outcome 1. Moderate release 1-2 ppm after 1 week Good 2. Low release 0.5-1 ppm after 1 week Weak effect 3. Negligible release <0.5 ppm after 1 week Ineffective

Sex: All, ages: 5 Years to 7 Years, accepts healthy volunteers

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Inclusion Criteria:

* Cooperative children (Frankl Scale 3)
* good oral hygiene (OHI-S Index),
* 2 partially erupted 1st molars

Exclusion Criteria:

* Cavitated caries
* fluorosis
* hypoplasia
* restored teeth

• Dr rabaa MAHMOUD ABOU Bakr, Professor, Principal investigator, Mansoura University - Pediatric Dentistry Clinic