Effect Of Implant Angulation On Accuracy Of Implant-Level Impressions

Objectives: Implant angulation is a common clinical situation that may result in inaccurate impressions and consequently may affect the accuracy of the definitive cast. This study was designed to compare the dimensional accuracy of casts obtained from direct impression technique for two definitive lower casts with implants at different angulations.
Methods: Three Osseolink implants were placed in three reference models (one implant at the midline and two implants at premolar regions on both side) with different angles (0, 15 and 30 degrees). Ten medium-consistency polyvinylsiloxane impressions of each model were made with direct impression technique. Impressions were poured with type IV dental stone. The inter-implant distances were measured for casts using a coordinate measuring machine and the deviations compared to the reference models were calculated. Data were analyzed using one-way ANOVA followed by post-hoc tests to detect significance between groups (a=0.05). Statistical analysis was performed using SPSS statistics software for Windows. P values ≤ 0.05 were considered statistically significant in all tests
Results: The distortion values of the duplicate casts of 30° angulated implants was significantly higher than distortion values for parallel implants and 15^° angulated implants (p<0.05), which were not significantly different from each other (p>0.05) for Dr1 and Dr2
Conclusions: The relation between the angulation and impression technique can be established that as with increase in angulation, the amount of forces of deformation increases