This study will compare the performance of newly introduced bioactive resin based pits and fissure sealant versus fluoride releasing filled resin based pits and fissure sealant in posterior molars prone to carious lesions of fissures in patients at risk of caries. Visual tactile examination and VistaCAM will be used for evaluation.

New bioactive resin pits and fissures sealant BioCoat® by Premier® presenting SmartCap™ Technology involving semi-permeable resin microcapsules. The rechargeable SmartCap microcapsules are filled with ionic solutions of fluoride, calcium and phosphate, supposing greater fluoride uptake in the presence of calcium and phosphate ions.

With no enough evidence based information in literature about using bioactive fissure sealants in susceptible fissures , it isd beneficial to evaluate the newly introduced material using a randomized clinical trial to test the null hypothesis that bioactive resin pit and fissure sealant will have the same clinical performance as flouride releasing filled resin based pit and fissure sealant in susceptible fissures.

Inclusion Criteria:

• Inclusion Criteria of participants:

  • Patients with caries susceptible fiss- ures in fully erupted first permanent molars showing nosigns of caries.
  • Co-operative patients approving to part- icipate in the trial.
  • Good oral hygiene.

• Inclusion Criteria of teeth:

  • Caries susceptible occlusal pits and fissures.
  • Intact contact with opposing teeth.
  • Teeth with no previous restorations in other surfaces.

Exclusion Criteria:

• Exclusion criteria of participants:

  • patients with Disabilities, systemic disease or severe medical complications.
  • patients have allergic history concerning methacrylate.
  • patients with rampant caries, xerostomia, evidence of severe bruxism, clenching, or tempromandibular joint disorders
  • participants who show lack of compliance.

• Exclusion criteria of teeth:

  • Carious pits and fissures.
  • Developmental tooth defect.
  • Partially erupted teeth
  • Periapical pathology or signs of pulpal pathology.
  • Tooth hypersensitivity.
  • Heavy occlusion and occlusal contacts.

Blinding to participants : will not know either the intervention or the comparator will be applied to their teeth Blinding to investigator: covering the 2 syringes with opaque seal to avoid performance bias Blinding to outcomes assessor: to overcome detection bias