Short-term retention of glass-ionomer fissure sealants

In some studies, rapid loss of glass-ionomer sealants has been reported. The aim of this study was, therefore, to examine the retention rate of 4 month old glass-ionomer sealants (Fuji III). The sealants were applied in 93 newly erupted molars and premolars. After four months, 75% of the sealants were totally present, 22% partially lost and 3% totally lost. No caries was observed. Impressions were taken from occlusal surfaces showing total or partial loss of sealants, and the casts were examined using a stereomicroscope or SEM. Examination revealed that in most of these cases, the material was still left in the bottom of the fissures. This may partly explain why glass-ionomer sealants have prevented caries even after they appear to have been lost. In order to examine the penetration of the sealant into the fissures, 28 teeth were sealed in vitro, bisected and examined using a stereomicroscope. In 19 cases, the sealant had penetrated whole fissure, in 7 cases two thirds of the fissure and in 2 cases one third of the fissure or less.