2. 46 A. Sisti et al.: Crestal minimally-invasive sinus lift
using rotatory instruments in case of very resorbed maxillary
crest ( < 5 mm).
An additional aim was to longitudinally verify the stability
of the augmented area.
Materials and methods
The present study was designed as a prospective case series
on maxillary sinus elevation with a crestal approach.
From June 2007 to October 2008, 20 consecutive patients
were enrolled in this study. They were followed up for 24
months after prosthetic loading. They all presented partially
edentulous posterior maxilla and a residual crestal height
ranging between 1.2 – 5.0 and > 7 mm. All patients were in
general good health. Exclusion criteria are summarized in
Table 1 . All patients were informed about the procedure and
signed a consent form. The present study was performed fol-lowing
the principles outlined in the Declaration of Helsinki
on experimentation involving human subjects.
Surgical protocol
To evaluate elevation and immediate implant insertion pos-sibility,
crestal height in implant site was measured in all
patients using cone beam CT (Figure 1 ).
Before surgical procedures, a full mouth professional pro-phylaxis
appointment was scheduled, and an antibiotic pro-phylaxis
was prescribed (1 g amoxicillin and clavulanic acid,
Neo Duplamox; Procter & Gamble, Rome, Italy) 2 h before
surgery and 2 g/day for 6 days.
A non-steroidal anti-infl ammatory drug (ketoprofene, 80
mg, Oki; Domp è SpA, L ’ Aquila, Italy) was given 1 h before
surgery and if patient requested for one.
After local anesthesia (Articain, Septodont, Saint-Maur-des-
Fossés Cedex, France with adrenaline 1:50.000), a papilla
preservation paracrestal fl ap with palatal approach was raised.
Buccal bone was minimally exposed to maintain protection and
periosteal vascularization of sinus lateral walls (Figure 2 A – C).
Rotary tools were used in the following manner:
1. After crestal bone assessments, perforation was done until
sinus fl oor level using a chamfered/rounded drilling bur
with a diameter of 3 mm (Sweden & Martina, Padua, Italy)
(500 rpm with irrigation) and controlled by stop.
2. Abrasion of sinus fl oor using a rounded drilling bur with a
diameter of 3 mm (250 rpm with irrigation) and controlled
by stop with 1-mm increment.
3. Manual check of the sinus membrane integrity with a
rounded probe for implant therapy (the integrity of the
membrane was assumed if a mirror did not appear wet).
4. Elevation of the mucosa and osteotomy regularization
using a rounded drilling bur with a diameter of 3 mm
(600 rpm) brought 1 mm deeper than the previous drill.
5. Insertion of 5 × 5-mm equine collagen sponges (Gingistat;
GabaVebas, Milan, Italy) until the bottom of the site
using bone carrier with a diameter of 3 mm to minimize
eventual mucosa microwearing.
6. Sinus mucosa elevation obtained plugging synthetic re-sorbable
hydroxyapatite granules (Nanobone; Artoss,
Dresden, Germany) imbued with blood as the only graft
material using a dedicated bone plugger.
7. Use of bone carriers with a stop to prevent sinus fl oor
penetration.
8. Insertion of an 11-mm-long, 4.25-mm-wide implants
with a minimum torque of 25 N cm (Premium Straight;
Sweden & Martina) (Figure 3 ).
9. Implants were submerged, and passive closure of the fl ap
was achieved with nylon 5.0 sutures (Polinyl; Sweden &
Martina) (Figure 4 ).
10. Immediate Cone Beam CT (Picasso; E-WOO Technology,
Gyeonggi Do, South Korea) was made after surgery to
evaluate possible dispersion of hydroxyapatite granules
in the sinus and to measure residual and augmented bone
(Figure 5 ).
11. Four months after implant insertion, surgical reopening,
healing screw positioning, and osseointegration checking
were done (Figure 6 ).
12. All implants were restored with defi nitive cemented
metal-ceramic crowns (Figure 7 ).
13. Cone beam CT examinations were repeated 24 months
after prosthetic loading to compare the amount of regen-erated
bone (Figure 8 A,B).
Table 1 Exclusion criteria.
• Untreated periodontitis
• Systemic contraindications to implant surgery
• Acute or chronic sinusitis
• Patients with history of sinus fl oor elevation
• Smokers ( > 10 cigarettes/day)
• Pregnant or lactating women
• Patients treated or under treatment with intravenous or oral
bisphosphonate therapy
Figure 1 Preoperative cone beam of a site with 2.5 mm native
bone.
3. A. Sisti et al.: Crestal minimally-invasive sinus lift 47
A
B
C
Figure 2 Clinical view of the crest (A) preoperatively, (B) after
papilla preservation incision, and (C) fl ap refl ection.
Figure 3 Implant insertion at the bone level after sinus elevation
and bone graft insertion.
Figure 4 Passive closure of the fl ap was achieved with nylon 5.0
sutures.
During the postoperative healing period, eventual clinical
symptoms of maxillary sinusitis were evaluated, and the sta-bility
of implants was tested by tightening the healing screw
and the defi nitive abutment. At every stage (reopening, abut-ment
connection, and last follow-up), implant stability was
radiographically tested and analyzed for progressive marginal
bone or infection.
Radiographic analysis
Using a dedicated software (EZ-Pax; E-WOO Technology,
Gyeonggi Do, South Korea), bone crest, augmented height,
and sinus mucosa thickness were measured on 0.1-mm sec-tions.
Bone levels were measured using implant platform
as reference point. The following data were measured as a
mean value of distal and mesial measurements parallel to the
implant axis:
• RC: residual crest bone height, distance from crestal bone
border (corresponding to the implant platform) to the sinus
fl oor.
• TH: total height of sinus fl oor elevation corresponding to
the distance between the bone crest and the radiographic
appearance of sinus fl oor elevation.
Figure 5 Immediate cone beam after surgery to evaluate possible
dispersion of hydroxyapatite granules in the sinus.
Measure of residual and augmented bone demonstrated 12 mm of
regeneration.
4. 48 A. Sisti et al.: Crestal minimally-invasive sinus lift
• RB: regenerated elevation height: calculated using the
RB = TH-RC formula.
In cone beam CT examination at 24 months after loading, it
was no longer possible to distinguish the original sinus fl oor,
and therefore, the RH value used was the value measured at
implant insertion: RB (at 24 months) = TH (at 24 months)-RC
(at implant insertion).
All assessments were made by an independent exam-iner
(M.P.M.) and were rounded off to the nearest 0.1 mm.
Additionally, CBCT scans were used to evaluate the thick-ness
of the sinus membrane and presence of possible sinus
pathology. Additionally, to standardize inclination of each
cross section, at the postoperative CBCT, neighboring tooth
long axis was selected as reference, measuring apicocoro-nal
length and reproducing it in the following CT using the
Image software (EZ-Pax Plus; E-Woo Technology, Gyeonggi
Do, South Korea).
Statistical analysis
For each CT measurement, descriptive statistics includ-ing
mean values and standard deviation were computed at
A
B
Figure 8 (A) Defi nitive restoration 2 years after prosthetic loading.
Soft tissue coronal creeping can be noted. (B) Radiographic analysis
demonstrated stable hard tissue level.
Figure 6 Soft tissue response after healing abutment removal,
4 months after implant insertion.
Figure 7 Defi nitive restoration.
the different time points (postoperative and 24 months after
loading).
Results
Seventeen patients (10 men and 7 women) were included
in this study. A total of 20 implants were inserted. Fourteen
patients received one implant and three received two
implants. No patient dropped out at the end of this study.
All surgical interventions and postoperative healing period
were without any serious complication or side effect. In the
fi rst postoperative day, 12 patients showed moderate swell-ing
without experiencing pain. After 1 week, no infl amma-tion
symptom was detectable. All implants were clinically
osseointegrated at surgical reopening and at 24 months after
prosthetic loading. Only one minimal mucosa laceration
was observed at the drilling phase. This complication did
not have unfavorable clinical consequences, and there was
no evidence of extruded material into the sinus at the last
radiographic follow-up. One abutment on single implant
was observed unscrewed before the last follow-up. Removal
of crowns, rescrewing of the implant/abutment screw, and
adjustment of occlusal contacts allowed no other prosthetic
complication before the end of the study. The radiographic
data are summarized in Table 2 .
The mean initial residual crests (RC) value was 4.12 ± 1.17
mm (range, 1.2 – 5.0 mm), and the mean elevation of sinus
mucosa (RB) obtained at implant insertion was 9.28 ± 2.04
mm (range, 6.6 – 13.4 mm). Twenty-four months after loading,
it was not possible to see the original sinus fl oor on CTCB
5. A. Sisti et al.: Crestal minimally-invasive sinus lift 49
Table 2 Characteristics of 20 maxillary sinus included in the study
presurgery, postsurgery, and 18 months after prosthetic loading
(in mm).
Residual
crest
Total
height
Regenerated
bone height
Total height
at 24 months
Regenerated
bone height
at 24 months
Mean 4.12 13.51 9.28 12.98 8.62
SD 1.17 1.41 2.04 2.53 3.26
Max 5 18 13.40 25.50 20.6
Min 1.20 11 5.40 10.10 4.4
scans. TH values ranged from 10.1 to 25.5 mm, with a mean
value of 12.98 ± 2.53 mm.
Discussion
Traditional crestal approach offers a good implant survival
rate as well as complications similar to lateral access tech-nique
[5, 8, 10, 26, 30] . However, crestal approach techniques
studied in literature are usually hard to standardize. In fact,
osteotomy techniques need a long learning process and expert
handling.
The main limit of such techniques lies in the diffi culty in
controlling the percussion power of the hammer to obtain
sinus fl oor breakage [1] ; the use of the mallet can also be
unpleasant for patients [8] and a few cases of vertigo syn-dromes
(benign paroxysmal positional vertigo) or acuphenis
provoked by percussions were reported [18] . Additionally, the
diffi culty in controlling the hammer is amplifi ed by the fact
that osteotomes being used for split-crest techniques or tra-becular
bone condensation are usually graduated to measure
distance > 8 – 10 mm. In fact, the lack of depth stops leads to
the diffi culty in using this tool.
The use of burs on low-speed handpiece seems to dramati-cally
decrease patient ’ s discomfort [8] .
Traditional osteotome techniques recommend at least 5 – 6
mm of crestal height and a maximum of 5 mm for the eleva-tion
[3, 5, 8] . However, in the present study, 20 implants were
inserted in residual crestal height ranging from 1.2 to 5.0 mm,
with a mean value of 4.12 mm.
At the same time, all cases were elevated over 5 mm (mean,
9.28 mm; range, 5.4 – 13.4 mm), which is usually considered
a limit for the elevation technique using crestal access with-out
diffi culties or complications [19] . These data seem to be
in accordance with recently published studies: Cannizzaro et
al. [3] and Checchi et al. [5] , in fact, demonstrated that crestal
approach sinus lift using drilling-dedicated burs can be success-fully
adopted even in a residual bone height lower than 6 mm.
Two years after loading, radiological analysis showed
similar outcomes with a minimal contraction of the graft
material ( < 8 % ). These data might be related to the nature of
the graft material used in the present study. In fact, the graft
material investigated in this study is a nanosized hydroxy-apatite
embedded in a highly porous matrix of silica gel.
The nanostructure produces a large, bioactive surface (84
m 2 /g) and presents a microporosity size ranging from 10 to
20 nm. This confi guration seems to be able to induce migra-tion,
adhesion, and proliferation of osteoblasts inside the pore
network and promote angiogenesis inside. In fact, G ö tz et al.
[13] showed that a nanostructure is integrated by the host ’ s
physiological bone turnover after 3 months. This could lead
to a fast regeneration of the grafted mass, minimizing physi-ological
shrinkage.
Additionally, data reported in the present study seem to be
in agreement with Canullo et al. [4] and Heinemann et al.
[14] , who demonstrated the same minimal graft contraction
24 months after loading in sinus lift with lateral approach.
In the present study, absence of dislocated graft mate-rial
in cone beam CT examination control was reported.
It might demonstrate that the proposed protocol does not
seem to determine mucosa laceration and neither does the
use of bur nor mucosa elevation with bone carriers, even
in cases where limits of classical indications for elevation
with osteotomes were exceeded. This could be explained
by the use of stops, allowing a perfect control of burs and
avoiding membrane perforation, according to Tilotta et
al. [28] . Additionally, the apical shape of the burs and the
sequence of use might prevent sinus membrane from nega-tive
impact.
To further minimize sinus mucosa wearing, microsponges
of equine collagen were inserted before grafting, using the
same procedure and tools of hydroxyapatite insertion. In
fact, in case of minimal sinus membrane laceration as it once
occurred in the present study, according to literature, the use
of collagen seem to be effective in mucosa repair [15] and
prevention of graft material dislocation.
On the contrary, with osteotome techniques, membrane
laceration ranging from 2 % to 5 % was reported in literature
[11, 26] . However, when the sinus elevation exceeds 5 mm,
sinus mucosa laceration rate ranges between 10 % and > 20 %
[16, 20] .
In the present study, despite the severe resorption of the
bone crest (1 – 5 mm in height), no implant failed at the sec-ond
surgery or after 24 months of loading, presenting better
results compared with the ones reported by Pjetursson et al.
[19] in their review.
However, together with the technique reported, fi xture
macrotopography and microtopography maybe considered as
cofactors in this high implant survival rate, as they have been
associated with the formation of a superfi cial fi brin network,
which could theoretically enhance the initial stability of the
bone/implant interface [21, 23] .
It must be noted that positive results from this study might
be infl uenced by the short follow-up period, the limited num-ber
of patients, and, despite the standardization of CT analy-sis,
by the absence of individual tri-dimensional radiographic
guides, which may have resulted in minimally different incli-nations
of the CT cross sections.
Concluding, it can be stated that the MISE technique, in
association with a nanostructured hydroxyapatite as graft
material, can be considered a simple alternative technique
to osteotomes in obtaining sinus fl oor elevation with crestal
6. 50 A. Sisti et al.: Crestal minimally-invasive sinus lift
approach. In fact, the elevations practiced in a non-invasive
and quick way were suffi cient to insert implants long enough
to exceed the coronal/implant ratio of 1:1.
Conclusions
The present study confi rmed that the present minimally-invasive
procedure was successful in obtaining sinus elevation and implant
osseointegration.
Acknowledgements
We highly appreciated the skills and commitment of Dr. Audrenn
Gautier and Dr. Henry Canullo in the supervision of the study.
Confl ict of interest statement
No free materials were received by the authors who do not have
fi nancial interest, either directly or indirectly, in the products listed
in the study.
References
[1] Berengo M, Sivolella S, Majzoub Z, Cordioli G. Endoscopic
evaluation of the bone-added osteotome sinus fl oor elevation
procedure. Int J Oral Maxillofac Surg 2004; 33: 189 – 194.
[2] Bruschi GB, Scipioni A, Calesini G, Bruschi E. Localized
management of sinus fl oor with simultaneous implant place-ment:
a clinical report. Int J Oral Maxillofac Implants 1998; 13:
219 – 226.
[3] Cannizzaro G, Felice P, Leone M, Viola P, Esposito M. Early
loading of implants in the atrophic posterior maxilla: lateral sinus
lift with autogenous bone and Bio-Oss versus crestal mini sinus
lift and 8-mm hydroxyapatite-coated implants. A randomised
controlled clinical trial. Eur J Oral Implantol 2009; 2: 25 – 38.
[4] Canullo L, Patacchia O, Sisti A, Heinemann F. Implant restoration
3 months after one stage sinus lift surgery in severely resorbed
maxillae: 2-year results of a multicenter prospective clinical
study. Clin Implant Dent Relat Res 2010. DOI:10.1111/j.1708-
8208.2009.00261.
[5] Checchi L, Felice P, Antonini ES, Cosci F, Pellegrino G, Esposito
M. Crestal sinus lift for implant rehabilitation: a randomised clin-ical
trial comparing the Cosci and the Summers techniques. A
preliminary report on complications and patient reference. Eur J
Oral Implantol 2010; 3: 221 – 232.
[6] Cosci F, Luccioli M. A new sinus lift technique in conjunction
with placement of 265 implants: a 6-year retrospective study.
Implant Dent 2000; 9: 363 – 368.
[7] Davarpanah M, Martinez H, Tecucianu JF, Hage G, Lazzara R.
The modifi ed osteotome technique. Int J Periodontics Restorative
Dent 2001; 21: 599 – 607.
[8] Del Fabbro M, Testori T, Francetti L, Weinstein R. Systematic
review of survival rates for implants placed in the grafted
maxillary sinus. Int J Periodontics Restorative Dent 2004; 24:
565 – 577.
[9] Emmerich D, Att W, Stappert C. Sinus fl oor elevation using
osteotomes: a systematic review and meta-analysis. J Periodontol
2005; 76: 1237 – 1251.
[10] Esposito M, Grusovin MG, Rees J, et al. Effectiveness of sinus
lift procedures for dental implant rehabilitation: a Cochrane
systematic review. Eur J Oral Implantol 2010; 3: 7 – 26.
[11] Ferrigno N, Laureti M, Fanali S. Dental implants placement in
conjunction with osteotome sinus fl oor elevation: a 12-year life-table
analysis from a prospective study on 588 ITI implants.
Clin Oral Implants Res 2006; 17: 194 – 205.
[12] Fugazzotto PA. Immediate implant placement following a
modifi ed trephine/osteotome approach: success rates of 116
implants to 4 years in function. Int J Oral Maxillofac Implants
2002; 17: 113 – 120.
[13] G ö tz W, Gerber T, Michel B, Lossd ö rfer S, Henkel K-O,
Heinemann F. Immunohistochemical characterization of nano-crystalline
hydroxyapatite silica gel (NanoBone ® ) osteogenesis:
a study on biopsies from human jaws. Clin Oral Implants Res
2008; 19: 1016 – 1026.
[14] Heinemann F, Mundt T, Biffar R, Gedrange T, G ö tz W. A 3-year
clinical and radiographic study of implants placed simultane-ously
with maxillary sinus fl oor augmentations using a new
nanocrystalline hydroxyapatite. J Physiol Pharmacol 2009;
60(Suppl 8): 91 – 97.
[15] Jeschke MG, Sandmann G, Schubert T, Klein D. Effect of
oxidized regenerated cellulose/collagen matrix on dermal and
epidermal healing and growth factors in an acute wound. Wound
Repair Regen 2005; 13: 324 – 331.
[16] Nkenke E, Schlegel A, Schultze-Mosgau S, Neukam FW,
Wiltfang J. The endoscopically controlled osteotome sinus fl oor
elevation: a preliminary prospective study. Int J Oral Maxillofac
Implants 2002; 17: 557 – 566.
[17] Nocini PF, Albanese M, Fior A, De Santis D. Implant placement
in the maxillary tuberosity: the Summers ’ technique performed
with modifi ed osteotomes. Clin Oral Implants Res 2000; 11:
273 – 278.
[18] Pe ñ arrocha M, Garcia B. Benign paroxysmal positional vertigo
as a complication of interventions with osteotome and mallet.
J Oral Maxillofac Surg 2006; 64: 1324.
[19] Pjetursson BE, Rast C, Br ä gger U, Schmidlin K, Zwahlen M,
Lang NP. Maxillary sinus fl oor elevation using the (transalveo-lar)
osteotome technique with or without grafting material. Part
I: implant survival and patients ’ perception. Clin Oral Implants
Res 2009; 20: 667 – 676.
[20] Reiser GM, Rabinovitz Z, Bruno J, Damoulis PD, Griffi n TJ.
Evaluation of maxillary sinus membrane response following
elevation with the crestal osteotome technique in human cadav-ers.
Int J Oral Maxillofac Implants 2001; 16: 833 – 840.
[21] Rompen E, Domken O, Degidi M, Farias Pontes AE, Piattelli
A. The effect of material characteristics, of surface topogra-phy
and of implant components and connections on soft tissue
integration: a literature review. Clin Oral Implants Res 2006;
17: 55 – 67.
[22] Rosen PS, Summers R, Mellado JR, et al. The bone-added
osteotome sinus fl oor elevation technique: multicenter ret-rospective
report of consecutively treated patients. Int J Oral
Maxillofac Implants 1999; 14: 853 – 858.
[23] Shalabi MM, Gortemaker A, Van ’ t Hof MA, Jansen JA,
Creugers NH. Implant surface roughness and bone healing: a
systematic review. J Dent Res 2006; 85: 496 – 500.
[24] Summers RB. Staged osteotomies in sinus areas: preparing for
implant placement. Dent Implantol Update 1996; 7: 93 – 95.
[25] Summers RB. Sinus fl oor elevation with osteotomes. J Esthet
Dent 1998; 10: 164 – 171.
[26] Tan WC, Lang NP, Zwahlen M, Pjetursson BE. A systematic
review of the success of sinus fl oor elevation and survival of
7. A. Sisti et al.: Crestal minimally-invasive sinus lift 51
implants inserted in combination with sinus fl oor elevation.
Part II: transalveolar technique. J Clin Periodontol 2008; 35:
241 – 254.
[27] Tatum H Jr. Maxillary and sinus implant reconstructions. Dent
Clin North Am 1986; 30: 207 – 229.
[28] Tilotta F, Lazaroo B, Gaudy JF. Gradual and safe technique for
sinus fl oor elevation using trephines and osteotomes with stops:
a cadaveric anatomic study. Oral Surg Oral Med Oral Pathol
Oral Radiol Endod 2008; 106: 210 – 216.
[29] Wallace SS, Froum SJ. Effect of maxillary sinus augmentation
on the survival of endosseous dental implants. A systematic
review. Ann Periodontol 2003; 8: 328 – 343.
[30] Zitzmann NU, Sch ä rer P. Sinus elevation procedures in the resorbed
posterior maxilla. Comparison of the crestal and lateral approaches.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998; 85: 8 – 17.
Received June 21, 2011; accepted December 12, 2011 ; online fi rst
January 9, 2012
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