Pits and Fissures: Etch Resistance in Prismless Enamel Walls

Abstract

Background: In a previous study to examine the nature of etching on the walls of fissures, there was a consistent result of resistance to deep etching on parts of the walls and a zone of lesser etching on part of the walls as evidenced by the uptake of stain. The staining had been used to examine the nature of the etch pattern. The aims of this study were to define the nature of this etch resistant area. Methods: A sample of 55 teeth, both molars and premolars, were divided into three groups. In the first group the wetting of fissures by the etchant was examined; the second group tested for the effects of pellicle-cuticle-debris or air entrapment on the etching process. The final group looked at alternative mechanical treatments of the fissure prior to etching. Results: The specimens split along the fissures showed clearly that the etch resistant zone was not due to lack of contact with the etchant or the presence of a pellicle-cuticle-debris covering, but to the presence of a prismless enamel structure. This study showed that this zone inhibited tag development on the fissure walls. Conclusions:The mechanical removal of this prismless layer of enamel within the fissure system should result in an improved bonding of a fissure sealant through better tag development, in turn leading to a reduction in the failure rate of a sealant used to prevent caries.

Pits and fissures: Relative space contribution in fissures from sealants, prophylaxis pastes and organic remnants

“…A more recent study 12 looked at the nature of the enamel forming the walls of fissures and showed this to be of a prismless structure. Hence, failure to achieve a satisfactory bond for fissure sealants may be due to the lack of tag formation following etching.…”

“…Previous studies 12 have investigated the presence of prismless layer of enamel at the fissure entrance as well as part of the walls of the fissure itself, which result in a reduced etching pattern. The presence of organic material within the fissure system has also been demonstrated.…”

Fissür örtücünün altına uygulanan adezivlerin makaslama bağlanma kuvveti ve mikrosızıntıya etkisi

“…The sound enamel surface is without prisms, hypermineralized and contains more inorganic material compared with the inner enamel layer. 22 and resin penetration, revealed by short resinous tags. 23 However, the effect of a self-etching primer system on the aprismatic structure of enamel is weaker than that of an etch and rinse adhesive system.…”

Operative Dentistry and the Abuse of Dental Hard Tissues: Confocal Microscopical Imaging of Cutting

“…The use of fissure sealants and preventive resin restorations is widespread, but anatomical features of the enamel fissure may conspire to reduce the effectiveness of the conditioning acids. 30 One feature that will reduce etching effectiveness is prism-free enamel, which may form in the outer layers (<100 mm thick) of enamel, reflecting lack of a Tomes' process at the secretory end of ameloblasts. Such prism-free enamel is especially prevalent in deciduous teeth and in the entrance to fissures (Figures 14 and 15).…”