The aim of this study was to investigate whether differences in surface treatment prior to repair influenced the seal of a resin fissure sealant placed on the occlusal surfaces of permanent molar teeth.
Setting: In-vitro study.
Sample and methods: One hundred and twenty-eight extracted human first and second molars were randomly allocated to one of four groups of 32 teeth each. A light cured, unfilled, opaque resin fissure sealant (Delton) was placed on their occlusal surface following cleaning by prophylaxis and acid etching. Following storage in artificial saliva (Saliva Orthana) for a week, duplication of sealant failure was carried out. The teeth were then subjected to one of four different surface treatments: Group 1: with a slow-speed prophylaxis brush followed by acid etching (control method); Group 2: a slow-speed bur and acid etching; Group 3: air abrasion and acid etching; and Group 4: acid etching and application of a bonding agent. Following a further week of storage in artificial saliva two layers of impermeable varnish were applied to the nonocclusal surfaces of the teeth; their apices were then sealed with wax and the teeth were immersed in 1% methylene blue for 48 h. The teeth were then sectioned (ISOMET 1000) to achieve three cuts resulting in a maximum of four blocks, i.e. six surfaces per tooth. A total of 715 sections from 126 teeth were scored for microleakage on the intact and repaired side of the fissure sealant.
Results: Statistical analysis did not demonstrate any one single method of repair to be superior to the control method for reapplication of the sealant.
Conclusion: All four techniques compared in this study seem to be acceptable for replacing or repairing lost or fractured fissure sealants. As prophylaxis with a brush rotating at slow speed followed by acid etching, which probably represents current practice, is also the simplest technique that can be practised on children, it is therefore recommended.