Replacing a missing lateral incisor always presents a dentist
with various challenges, notably the need to ensure an esthetic
result and long-term clinical viability in restoring oral health
and functionality. Due to concavities in the premaxilla region the
implant apex is often placed with a cant to the palate. This dilemma
can be solved with custom abutments which increase the cost of the
case. The SMART base allows up to 25 degrees of angle correction
which allows for screw retention in these cases (Figure 1). Figure 2
shows a radiograph of a missing lateral incisor and a pre-operative
template of a wax-up. An implant is then placed in the jaw and
allowed to heal for 6-8 weeks to ensure osseointegration (Figure
3). Thereafter, a temporary abutment is placed, adjusted and after
the screw is removed, a cotton pellet is placed to close the aperture
and protect the abutment threads (Figure 4). The temporary
abutment is then “picked-up” using a flowable composite while an
emergence profile and screw access is created with the composite
resin (Figure 5). The temporary restoration is then placed, and the
retaining screw torqued to 15Ncm (Figure 6). Thereafter, the screw
access is closed with a cotton pellet and composite resin (Figure
7). The SMART base can then be scanned (Figures 8) and digitized.
The final screw-retained zirconia restoration can then be fabricated
using CAD/CAM technology and placed in the mouth (Figure 9).
The final result is shown in Figure 10.
Figure 1: Angle correction of the smart base.
Figure 2: Radiograph and pre-operative template of wax-up.
Figure 3: Implant placed and allowed to osseointegrate.
Figure 4: Placement of the temporary abutment, adjustment and protecting abutment aperture and threads with a cotton
Figure 5: Picking-up the temporary abutment and creating both an emergence profile and screw access.
Figure 6: Temporary restoration placed, and the retaining screw torqued to 15Ncm.
Figure 7: The screw access is closed with a cotton pellet and composite resin.
Figure 8: a, b Scanned and digitized images of the SMART base.
Figure 9: Placement of the final screw-retained zirconia restoration.
Figure 10: Final result.
The technique outlined here is a simple and direct approach to
dealing with a missing lateral incisor and an implant which requires
angle correction. The advantage of this methodology is that intraoral
procedures are held to minimum whereas maximum advantage
is taken of modern dental technology, notably prefabricated
abutments, digital scanning and CAD/CAM fabrication of screwretained
restorations. Because modern technology is involved in
every step of the treatment planning and restoration fabrication,
clinician time is saved, patient discomfort (and expense) is held to
a minimum and the restoration will achieve the desired objectives
with minimal time wastage.