The range of the various maximum permissible errors due to the metal sleeve/osteotomy drill combination is presented in Table 1.

Concerning the error at the apex, two reference tables were reported (Tables 2 and 3). In these tables, the deviation of the implant axis was also tabulated. A separate table (Table 4) tabulated the error at the neck.

Multiple regression analysis was conducted to examine the relationship between the error at the apex, the error at the neck and the various predictors. Table 5 summarises the analysis results. The multiple regression model for the error at the apex with all three predictors (total length, sleeve length, clearance) produced R² = 0.98, F (3, 751) = 12,754, p < 0.0005. The multiple regression model for the error at the neck with all three predictors (offset, clearance, sleeve length) produced R² = 0.97, F (3, 543) = 5677, p < 0.0005.

The models:

The values of total length and offset are in mm whilst the values of clearance are in μm.

As it is shown in Table 5, the total length, clearance and offset have positive and significant regression weights indicating that guided surgery with higher scores on these scales is expected to have higher errors in the implant positioning after controlling for the other variables in the model. The sleeve length has a significant negative weight indicating that after accounting for the rest of the variables, surgical guides with increased sleeve length are expected to have lower errors in implant positioning.