Retention and caries outcomes of pit-and-fissure sealants with versus without a bonding agent: a systematic review

Abstract Background The adjunctive use of a bonding agent before pit-and-fissure sealant placement has been proposed to improve sealant retention, but its additional effect on caries outcomes remains uncertain. This systematic review evaluated retention and caries outcomes of pit-and-fissure sealants placed with versus without a bonding agent. Methods PubMed/MEDLINE, Embase, Web of Science, the Cochrane Library, and Scopus were searched from inception to 30 January 2026 for randomized controlled trials comparing sealants placed with versus without a bonding agent after acid etching. Risk of bias was assessed using Cochrane RoB 2. Findings were synthesized narratively, and certainty of evidence was assessed using GRADE. Results Ten publications representing nine randomized split-mouth trials involving 581 unique children were included. Several trials reported higher sealant retention with a bonding agent, whereas others found little or no additional benefit. Findings varied across studies with differences in adhesive strategy, tooth substrate, isolation method, retention criteria, and follow-up duration. New caries events on initially sound teeth were generally uncommon, and no consistent additional benefit of bonding was demonstrated. One trial evaluated progression of pre-existing ICDAS 2–4 lesions and reported rare progression without a significant between-group difference. The certainty of evidence was very low for retention, low for new caries incidence, and very low for progression or control of pre-existing lesions. Conclusions Bonding agents may improve pit-and-fissure sealant retention in some clinical settings, but the magnitude and persistence of this benefit remain uncertain. Current evidence does not demonstrate a consistent additional benefit for caries outcomes. Future split-mouth trials should report paired binary outcome data or appropriately adjusted effect estimates to permit valid quantitative synthesis. Systematic review registration PROSPERO CRD420261330855.