Study of prepared tooth displacement based on digital jaw model comparison

BACKGROUND: Despite extensive research on the prevention and treatment of dentoalveolar shifts in cases of dental arch defects, which develop over time, there is a lack of studies examining errors related to the displacement of prepared teeth during the laboratory fabrication of a prosthetic restoration.

With the introduction of digital technologies in clinical practice, it has become possible to assess the displacement of a prepared tooth and determine the optimal treatment duration.

CLINICAL CASE DESCRIPTION: This report presents a clinical case of prosthetic treatment in a patient diagnosed with “hard tissue defect of tooth 2.6, occlusal surface destruction index ≥ 60%,” using a digital protocol.

To analyze the extent of displacement of the prepared tooth toward the antagonists over a known period, the distance to the antagonist teeth was measured using digital models.

Digital images of the jaw models obtained immediately after tooth preparation were designated as baseline data. After 24 days, new impressions were taken, and the corresponding digital models were recorded as current data.

The digital models were superimposed in the position of centric occlusion, and the distances in the baseline and current datasets were measured ten times. To assess the displacement of the prepared tooth, the measured values were compared.

This clinical case justified the duration of prosthetic treatment considering the displacement error of the prepared tooth based on digital model comparison. Statistically significant differences were found between the measurements taken over the specified time period. The mean value of the initial measurements was 1.345 ± 0.005 mm, while the mean value of the current measurements was 1.229 ± 0.003 mm. The difference between these values indicates that the prepared tooth shifted by 0.116 ± 0.002 mm (116 ± 2 µm).

CONCLUSION: Considering the clinical findings of this study, it is recommended that fixed prosthetic treatment without the use of temporary restorations be completed within the shortest possible timeframe. The measured displacement of the prepared tooth toward the antagonist teeth, as observed on digital jaw models, indicates that laboratory fabrication of a prosthesis without a temporary restoration beyond 24 days is critical, as it leads to prosthetic misfit.