Fluoride release, microbial inhibition and microleakage pattern of two orthodontic band cements

Objectives: To compare, in vitro, the fluoride release, microbial inhibitio n and microleakage pattern of a conventional glass ionomer cement (Ketac-Ce m) and an acid-modified composite (Ultra Band-Lok) for band cementation. Methods: Fluoride release was measured from cement discs (3.0 mm diameter a nd 1.5 mm thick) at regular intervals over 40 days using a potentiometric m ethod, Microbial inhibition was determined for each cement using an agar di ffusion test against one of four different strains of Streptococcus mutans. Thirty pairs of banded third molars (15 banded pairs for each cement) were thermocycled and microleakage determined by a dye penetration method. The depth of microleakage was assessed by an index applied by two examiners ind ependently to photographic records taken of the mid-buccal aspect of each t ooth. Results: The cumulative and daily fluoride release for days 5, 15 and 40 we re significantly greater for Ketac-Cem than for Ultra Band-Lok (all p < 0.0 5). After the initial set, the anti-microbial activity was significantly gr eater for Ketac-Cem than for Ultra Band-Lok over the following 24 h period for all four strains of S. mutans (all p < 0.05). There was no significant difference between the two cement groups for microleakage at the cement/ena mel interface (p = 0.66) but a borderline significance was detected for mic roleakage at the cement/band interface (p = 0.051). Conclusions: The fluoride release and anti-microbial activity of Ketac-Cem were greater than that of Ultra Band-Lok. There was no significant differen ce in microleakage between the cements at the cement/enamel interface but a borderline difference existed between the cements at the cement/band inter face. (C) 1999 Elsevier Science Ltd. All rights reserved.