Comparison of retention of resin-based filled and unfilled pit and fissure sealants using different isolation techniques

The aim of this randomized clinical trial was to evaluate the retention performance of filled and unfilled fluoride-containing resin-based fissure sealants applied to permanent first molars of children, and to assess the effect of rubber dam and cotton roll isolation techniques over an 18-month period. A total of 100 children/200 teeth participated in the study. The study was designed as a randomized, single-blinded, split-mouth trial. Mandibular permanent first molars of each patient divided into two groups: a-highly-filled pit-and-fissure sealant (Fissurit FX, Voco, Cuxhaven, Germany) and a-non-filled pit-and-fissure sealant (Teethmate F-1, Kuraray, Okayama, Japan), both containing fluoride. Considering the method of isolation of the dry working field, each group was further divided into two subgroups: rubber dam isolation and cotton roll isolation. The retention of the sealing material was analyzed at 6, 12, and 18 months. The primary outcome of the study was sealant retention, while the presence of caries lesions was recorded as a secondary outcome. The data were statistically analyzed at a significance level of 0.05. At the 18-month follow-up, the complete retention rates were 76.4% for Teethmate F1 (80.0% with cotton-roll isolation, 73.0% with rubberdam isolation), and 58.3% for Fissurit FX (59.5% with cotton-roll isolation, 57.7% with rubberdam isolation), respectively. There was no statistically significant difference between the groups in terms of the effect of isolation methods on the retention of materials. No caries lesion was detected among all the teeth being followed up after 18 months. Within the limitations of this study, sealant retention was more strongly influenced by filler content than by the isolation method used, with unfilled fluoride-containing sealants showing superior long-term retention. Both sealant types provided effective caries prevention over the 18-month follow-up period. Both fluoride-containing filled, and non-filled pit-and-fissure sealants demonstrated comparable retention and caries-preventive effects over 18 months, regardless of the isolation method, supporting their flexible use in clinical practice. The study was registered at CliniccalTrials.gov (Registration number: NCT07110701; Date of registration: 07 August 2025).