Thirty-six months in vivo wear of enamel antagonists to monolithic zirconia crowns
摘要
The aim of the study was to evaluate antagonist enamel wear caused by posterior monolithic zirconia crowns, and the wear of contralateral enamel/enamel tooth pairs over a 36-month observation period.
Materials and methodsOut of thirty-two patients, each provided with one 5 mol% yttria-stabilized zirconia crown on a natural tooth, ten met the inclusion criteria. The surfaces were captured with an intraoral scanner at baseline and after 36 months. The datasets were superimposed, and the mean maximum vertical height losses of the wear facets of the zirconia crowns, the control teeth, and the antagonist teeth of the crowns and the control teeth were determined. The null hypothesis stated was that there was no significant difference between the wear ratio zirconia crowns/enamel antagonists and the wear ratio control teeth/antagonists.
ResultsThe mean maximum vertical loss for the antagonist teeth to the zirconia crowns was 216 µm (SD ± 113 µm). For the contralateral antagonist pair, a mean vertical loss of 151 µm (SD ± 59 µm) and of 113 µm (SD ± 57 µm) was measured, respectively. The zirconia crowns exhibited 38 µm (SD ± 14 µm). The wear ratios of zirconia crowns/antagonists and control teeth/antagonists differed significantly exhibiting 0.25 (SD ± 0.19) and 1.55 (SD ± 0.79), respectively.
ConclusionThe monolithic zirconia crowns induced approximately twice the amount of wear on opposing enamel compared with natural tooth contacts.
Clinical relevance.
After three years, the monolithic zirconia crowns caused significantly greater antagonist enamel wear than natural enamel contacts, yet the wear was comparable to that observed for other dental ceramic materials.