PATHOGENESIS AND MODIFYING FACTORS OF DENTAL EROSION

Dental erosion is caused by acidic solutions which come into contact w ith the teeth. Because the critical pH of dental enamel is approximate ly 5.5, any solution with a lower pH value may cause erosion, particul arly if the attack is of long duration, and repeated over time. Saliva and salivary pellicle counteract the acid attacks but if the challeng e is severe, a total destruction of tooth tissue follows. Ultrastructu ral studies have shown that erosive lesions are seen in prismatic enam el as characteristic demineralization patterns where either the prism cores or interprismatic areas dissolve, leading to a honeycomb structu re. In aprismatic enamel the pattern of dissolution is more irregular and areas with various degrees of mineral loss are seen side by side. In dentin the first area to be affected is the peritubular dentin. Wit h progressing lesions, the dentinal tubules become enlarged but finall y disruption is seen also in the intertubular areas. If the erosion pr ocess is rapid, increased sensitivity of the teeth is the presenting s ymptom. However, in cases with slower progression, the patient;may rem ain without symptoms even though the whole dentition may become severe ly damaged. Regarding the role of causative agents, present data does not allow the ranking of different acids with regard to their potentia l of causing erosion. Neither is there consensus as to how effective f luorides are in preventing the progression of erosive lesions, or how the chemical and structural factors of tooth tissue in general might m odify this pathological process.