Background information
4.1.2 Healing time for the staged approach
Avoiding autogenous bone
Pascal Valentini: “I entirely dispense with using autogenous bone in sinus floor augmentation. Various clinical studies with histomorphometric analysis have demonstrated that using
autogenous bone only, or in combination with bone substitutes, does not lead to an amelioration of the clinical outcome (1). Grafting of the bone, however, extends the operation time,
creates a new surgical site and complicates the course of surgery. The successful use of BioOss® alone in sinus floor augmentation has been demonstrated in various publications
(3,4,5). Hence I only use Bio-Oss® for sinus floor augmentations without any addition of
autogenous bone. Yet, I make sure I keep Bio-Oss® in close contact with the bone walls. At
these contact sites new bone will grow in. Therefore, I use small granules of Bio-Oss® (0.25 1 mm particle size).”
Pascal Valentini: “As a general rule implants may already be inserted after a healing period of 4 months as the bone formation takes place in the first 3 months after the augmentation surgery. This is confirmed by the radio-opacity in the radiograph 3 months
after augmentation. Implants with rough surfaces can be loaded 2 months post-operatively.”
Fig. 9 Bio-Oss® completely fills the lateral
window aligned with the buccal bone wall.
Fig. 8 A perforation of the Schneiderian
membrane that occurred during surgery is
covered with Bio-Gide®.
After application of Bio-Oss®, Bio-Gide® is
positioned over the lateral window. Clinical
investigations have demonstrated that application of membranes over the lateral window
increases the implant survival rate significantly (2).
2. Main emphasis of this case presentation
> Clinical procedure for one- and two-stage procedure without use of autogenous bone. Tips
and tricks for preparing the lateral window, dealing with perforations of the Schneiderian
membrane or with septa.
Fig. 10 The lateral window is covered
with a Bio-Gide® membrane.
3. The lateral window technique –
Surgical procedure on the basis of a case with two-stage approach
Fig. 1 Clinical situation pre-operatively
Fig. 2 Atrophied posterior maxilla with insufficient bone height (< 2 – 3 mm).
Radiographic picture shows low radio-opacity on the day of surgery (left picture). The radio-opacity of the augmented area 3 months postsurgically (right picture) reveals an advanced mineralisation process.
4.2 The window
Pascal Valentini: “The position of the lateral window is generally chosen close to the mesial wall of the sinus at a distance of approximately 2 mm. The relative position of this wall to the apex of the tooth next to the edentulous area can be determined by using
a panoramic radiograph. In the case of an edentulous maxilla, a surgical guide stent with radio-opaque marks may be used to
visualise the position. In addition, the measurements of the sinus floor have to be transferred to the surgical site.”
Fig. 11 The incisions on the ridge and the
releasing incisions are sutured with resorbable 4.0 suture material. Postoperatively
patients are instructed to clean this region
with a soft brush (Inava® post-op 7/100)
and 0.12 % chlorhexidine.
Fig. 3 Alveolar ridge incision with releasing
incisions along the sulcus of the adjacent
tooth.
Fig. 12 Post-surgical radiograph shows the
augmented region and the implants inserted.
Panoramic radiograph of an edentulous
maxilla. The surgical guide stent allows the
positioning of the lateral window to be determined relative to the mesial wall.
4. Tips and tricks for the surgical procedure (with examples from different cases)
4.1 Implantation and bone augmentation – Simultaneously or staged?
Fig. 4 Raising of the mucoperiostal flap
after mesial releasing incisions. Initially the
detachment of the bony lid is performed
either with a diamond bur or an ultrasonic
end piece.
Fig. 5 For final detachment of the bony lid
an ultrasonic instrument is used.
Fig. 6 Careful elevation of the Schneiderian
membrane from the bone walls with a raspatorium.
4.3 Size of the window
Pascal Valentini: “Today’s modern implants possessing a micro-thread and conical form allow primary stability at a bone height of 2 –
3 mm. Thus simultaneous implantation and bone augmentation can be carried out more often than in the past. The simultaneous procedure should not be chosen if bone quality is particularly bad. This includes absent cortical bone or deep defects on the crest of the
ridge. In this case a staged approach should be chosen.”
Pascal Valentini: “I am keeping the diameter of the lateral window as small as possible in order to allow the largest contact surface between Bio-Oss® and the bone wall. In addition, it provides stability for the bone substitute. The window is therefore a little
larger than the diameter of the syringe I use to insert Bio-Oss® into the subantral cavity.”
4.1.1 The simultaneous approach
Pascal Valentini: “When implantation and augmentation are performed at the same time I generally load implants 6 months after
implantation. Ongoing clinical investigations are analysing whether reduction of this healing process to 4 months is possible .”
Pascal Valentini: “In most of the cases I push the bony lid inside the subantral space. Bio-Oss®
granules, which are applied subsequently, are thereby stabilised. Moreover the complete
removal of the bony lid would increase the risk of perforating the sinus membrane.”
Bio-Oss® granules are inserted in the subantral space. In this case a disposable syringe was used (tuberculin sterile syringe,
1 ml). The tip of the syringe is cut in order
to fill it with Bio-Oss®.
Fig. 7 The bony lid is left in the subantral space.
After filling Bio-Oss® into the subantral
space the implant is 6