In this study, the retention and wear of a trial material of light-activated glass ionomer cement specifically designed for pit and fissure sealing was evaluated clinically over a period of 12 months. A total of 65 first and second permanent molars of 42 children aged 5-12 years were selected. After cleaning pits and fissures with ultrasonic equipment, each tooth was isolated with cotton rolls and dried with air. GC Dentine Conditioner was then applied for 20 seconds, rinsed with water and dried with air. The powder and liquid of a light-activated glass ionomer were mixed and applied to the teeth, followed by light illumination for 20 seconds.
At the recall visits after 3 months(90±45 days),6 months(180±45 days),9 months(270±45 days)and 12 months(360±45 days), the retention and wear of the sealant were clinically examined. The results showed that 40/41 teeth,30/31 teeth,41/44 teeth and 28/31 teeth were regarded as having complete retention in the respective examination period. In some of the cases, replicas were prepared, which were subjected to examination under the scanning electron microscopy. The results showed that 40/41 teeth,30/31 teeth,35/42 teeth and 12/24 teeth were regarded as having complete retention in the respective examination period.
Examination under the scanning electron microscopy revealed that the partial loss of sealant materials which resulted in the partial exposure of the enaumel surfaces in certain grooves occurred in some cases; partial loss of sealant was observed in the grooves connecting the mesiobuccal pit and mesial pit for the upper molars and in the buccal grooves at the corner of the occlusal surface and the buccal surface for the mandibular molars. Howevar, neithere complete loss of sealant nor the development of secondary caries was observed in any cases over a period of 12 months.