© 2008 The Authors 368 Journal compilation © 2008 BSPD, IAPD and Blackwell Publishing Ltd DOI: 10.1111/j.1365-263X.2007.00896.x Blackwell Publishing Ltd Heat-treated glass ionomer cement fissure sealants: retention after 1 year follow-up KRISTINA SKRINJARIC, DUBRAVKA NEGOVETIC VRANIC, DOMAGOJ GLAVINA & ILIJA SKRINJARIC Department of Paediatric Dentistry, School of Dental Medicine, University of Zagreb, Zagreb, Croatia International Journal of Paediatric Dentistry 2008; 18: 368– 373 Objective. The aim of this study was to assess the retention rate of glass ionomer cement (GIC) fissure sealants heated during setting time. Methods. One hundred and twelve teeth with well- delineated fissure morphology were sealed with composite resin and GIC. Composite resin (Helioseal F, Vivadent) was used in control group A (56 teeth). GIC (Fuji VII, GC) was applied using split-mouth design with conditioning in group B (26 teeth) and without surface conditioning in group C (30 teeth). GIC was heated with external heat source (Elipar Trilight, Espe) for 40 s during the setting time accord- ing to the manufacturer’s instructions. Fissure sealants were evaluated 1 year after clinical service. Results. Retention rate in group A was 80.4% after 1 year of clinical service. Group B showed retention rate of 30.8%, and group C of 26.7%. Two new caries lesions were detected in groups B and C. Significant differences in retention between the composite group and GIC groups were obtained by Kruskal–Wallis and Mann–Whitney tests. Conclusion. It could be concluded that retention rate of GIC sealing treated with heat during setting time was significantly lower than retention of con- ventional composite resin. The heating procedure during setting of GIC sealants cannot be recom- mended as routine treatment in clinical practice. Introduction Pit and fissure sealant use is an effective clinical regime available for preventing occlusal caries 1–3 . The most widely used fissure sealants are based on bis-glycidyl methacrylate (Bis-GMA) resins. These resins were first introduced as restorative materials in 1963 4 . Cueto and Buonocore suggested the sealing of pits and fissures with an adhesive resin in 1967 5 . A second group of materials used as fissure sealants are the glass polyalkenoate cements 6–10 . To achieve maximum caries preventive effect on occlusal surfaces, dental sealants should have several properties. Perfect adhesion of material should be maintained not only while setting, but also during function (including challenge of thermal and mechanical cycling). Dimensional changes of material during application should be minimal. Complete retention of sealant material in the occlusal fissures depends for a long time on the dimensional changes, resistance to wear and fracture along with easy handling, and powerful preventive effect. Good preventive effect today means substantial release of fluoride ions 11,12 . Morphis et al. 13 reviewed the literature on the effectiveness of fluoride-releasing sealants. There is an evidence for equal retention rates to conventional sealants, ex vivo fluoride release, and reduced enamel demineralization. Glass ionomer cements (GICs) are also proposed for pit and fissure sealant materials. They have several advantages compared to classic resin sealant materials: lower susceptibility to moisture, easy handling, and fluoride releasing at a con- tinuous rate 11,12 . However, different studies have shown significantly lower retention rate compared to resin sealants 14–17 . The mechanical properties of glass ionomers are inferior to resin materials. The question of the caries pre- ventive effect of glass ionomer sealants is still controversial: different studies have shown different preventive effects 10,14,16,18,19 . It was suggested that after loss of sealant, the eventual presence of material remnants in the fissures can maintain caries prevention 18,20,21 . The treatment of glass ionomer material with heat was recently introduced 22 . The idea Correspondence to: Kristina Skrinjaric, Department of Paediatric Dentistry, School of Dental Medicine, University of Zagreb, Gunduliceva 5, 10 000 Zagreb, Croatia. E-mail: kristina.skrinjaric@zg.t-com.hr