Purpose: The current cross-sectional study aims to introduce a new method for the labiopalatal
positioning and angulation of immediately placed dental implants in the anterior
maxilla with relation to the type of abutment used (straight/angled abutment). Material and
methods: Cone beam computed tomography scans from the database of a private practice
were searched for patients who received immediate implants in anterior maxilla. After
superimposition of the initial and post-operative scans, incisal/root angle (IRA),
incisal/implant angle (IIA) and the difference between both angles were measured.
Furthermore, assessment of whether the implant position would be lying within the safe angle
or not. Age, gender, tooth/implant site and type of prosthetic abutment (straight/angled) were
retrieved from patients’ records. Results: Seventy-four patients with a total of 95 immediate
implants were selected for analysis. In regard to the type of abutment, 76 (80%) were
straight, while 19 abutments (20%) were angled. Regardless of abutment type, 72 implants
(75.8%) lay within the safe angle while 23 implants (24.2%) did not lie within the safe angle.
All 19 implants with angled abutments were not lying within the safe angle. There was a
statistically significant association between type of abutment, IRA, difference between IIA
and IRA, gender and lying within the safe angle (P-value <0.001, OR = 19, P-value <0.001,
Effect size = 0.904, P-value <0.001, Effect size = 1.209 and P-value <0.001, OR = 2.995
respectively). There was no statistically significant association between IIA, site or age and
lying within the safe angle (P-value = 0.757, Effect size = 0.063, P-value = 0.200, Effect size
= 0.184 and P-value = 0.387 Effect size = 0.208, respectively). There was a statistically
significant association between IRA, difference between IIA and IRA and type of abutment
(P-value = 0.001, Effect size = 0.762, P-value <0.001, Effect size = 1.056, respectively).
Conclusions: The Safe Angle Concept can be used as a reliable planning tool to choose the
correct IIP position in the anterior maxilla. Applying the safe angle concept will decrease the
use of angled abutment for prosthetic correction.