RETENTION AND CARIES-PREVENTIVE EFFECTS OF A GIC AND A RESIN-BASED FISSURE SEALANT

Fissure sealing using partially filled resins is an established caries preventive practice. Glass ionomer cement (GIC) sealants may offer additional advantages due to their ability to bond chemically to enamel and release fluoride. The aim of this study was to compare the caries preventive effect and retention of a GIC and a resin-based sealant. Ketac-fil(R) was tested against a chemically cured resin-based material (Delton(R)) using a split mouth design. Perth (Western Australia) schoolchildren (n = 465), mean age 7 yr +/- 0.72 (S.D.), received sealants on the occlusal surfaces of sound homologous permanent first molar pairs. Test (GIC) and control (resin) sealants were systematically allocated to left and right sides based on the child's month of birth, and were placed by dental therapists. After 3.64 +/- 0.11 yr, 415 children were examined by different clinicians, and the clinical status of the teeth and the extent of sealant retention recorded. Sealants were deemed retained when at least 2/3 of the fissure pattern was still sealed. In 252 tooth pairs, neither sealant was retained to this extent. In 71 pairs, the GIC was not retained and the resin sealant retained. In 40 pairs the reverse occurred (McNemar's test, chi(2) = 8.66, P < 0.005). Net gain (additional lesions prevented by the test agent per 100 treatments) was 6.1% (95% CI 3.3%, 8.9%). Effectiveness of the GIC was 80.6% (95% CI 59.6%, 90.7%). The relative risk of caries in test teeth was 0.19 (95% CI 0.09, 0.40). The study suggests that complete retention of GIC sealant is not necessary for caries prevention in newly erupted permanent first molars.