White spot reduction when using glass ionomer cement for bonding in orthodontics: a longitudinal and comparative study.

The aim of this clinical study was to test the benefit from using glass ionomer cement (GIC) instead of a conventional diacrylate in bracket bonding for the prevention of white spot formation. Before treatment 7.2 per cent of all examined surfaces (n = 222) were classified as having white spots. No additional fluoride treatment other than fluoride toothpaste was prescribed. At debonding 8-39 months later, white spots were found in 24 per cent of the surfaces bonded with the cement, significantly lower than the 40.5 per cent bonded with the diacrylate (P < 0.01). At recall 12 months after debonding (examined surfaces n = 214) the frequency of surfaces with white spots was reduced to 22 and 24 per cent respectively. Re-examination after a further 12 months (n = 160) showed that white spot surfaces were less frequent with the cement (16 per cent compared with the diacrylate 29 per cent), but still significantly more frequent in both groups than before treatment. With longer treatment time (17 months) teeth bonded with diacrylate were more frequently affected with white spots (P < 0.05). Neither sex nor age affected the results. It is concluded that the use of a GIC for orthodontic bonding will result in a significant reduction in the number of white spot surfaces at debonding compared with the use of conventional diacrylate. Although markedly reduced in both groups, the number of affected surfaces was still higher 2 years after debonding than before treatment.