Toothbrush abrasion resistance of different pit and fissure sealant systems in vitro

Abstract

When pit and fissure sealants were first introduced ln the late 1960's, they were not universally accepted. Today, however, sealants are used more frequently and their safety and effectiveness in preventing occlusalal caries have been proven time and again by dental researchers. The first of these studies was conducted by Cueto and Buonocore in 1967[14]. Since then numerous other studies have confirmed that sealants effectively prevent occlusal caries. A fissure is fully protected against caries as long as it is completely sealed[27,53,57]. Indeed, not a single study has shown that caries developed in pits and fissures under an intact sealant. This preventive measure enjoys the advantages of tooth conservation and the simplicity of application that allows its administration by relatively unskilled personnel. To provide adequate protection of caries-susceptible areas on the occlusal surfaces of molars and premolars, the sealant must be retained for a significant time (i.e. beyond one or two years). Once a part of the fissure has become uncovered by loss of sealant, protection against caries is no longer assured. Although clinical studies of the efficacy of fissure sealants have shown excellent sealant retention with high percentage of occlusal caries reduction,[40,59,63] the problem of loss of sealant still exists. Sealant loss is dependent on two main factors, the application technique at the time of placement which is controllable by the operator and the wear forces in the oral cavity. In addition to the earlier resin based pit and fissure sealants, glass lonomer cements have been introduced in the 1970's as potential sealants among other uses. These materials have the advantage of forming a bond with calcium ions and do not require etching of the enamel prior to their application. The literature is lacking information concerning the abrasion resistance of different resin sealants and glass lonomer materials, but wear may be an important factor of sealant loss. The present investigation is an attempt to qualify wear resistance of different sealant systems in vitro using the toothbrush abrasion technique.