Dental implants have
After almost 50 years, the placement of a titanium screw with an
attached tooth has now grown to be society’s standard for permanently
replacing missing or severely damaged teeth.
The enthusiastic intention to treat edentulous maxillary areas with
endosseous implants has often clashed with the assumption that the loss
of teeth is reflected in progressive bone reabsorption.
This bone deficiency may result from an excessive
pneumatization/inflammation of the maxillary sinus, from an important
atrophy of the alveolar crest referable to dental extractions and/or
periodontal diseases, from both of these causes.
Inflammation of the maxillary sinus, such as rhinitis and sinusitis
usually co-exist and are concurrent in most individuals; thus, the
correct terminology is now rhinosinusitis.
Because dental implantation and sinus augmentation have been widely
performed in recent years, one of their possible complications,
maxillary sinusitis, has become a major concern for both dentists and
A widely used technique for augmenting bone tissue volume in the maxilla
is maxillary sinus lifting, in which, by means of osteotomy of the
anterior maxillary sinus wall, the sinus membrane is exposed, and must
be divulsed to obtain a receptor site for the bone tissue.
One of the most common accidents in this technique is perforation of the
sinus membrane while performing osteotomy which, in some cases may make
a further surgical procedure unfeasible.
Vercellotti et al. was a pioneer when he presented the use of
piezoelectric ultrasound as a new alternative in performing osteotomies
in maxillary sinus lifting surgeries. Piezosurgery appears to be an
extremely advanced and conservative tool when compared with the existent
methods for the treatment of bone and soft tissues.
The osteotomy is performed by means of pendular vibratory movements,
with nanometric variations of amplitude, by the use of various points.
Nowadays, international consensus or scientific literature about the
possibility to perform oral rehabilitation and maxillary sinus grafting
in the case of pre-existing sinus membrane pathology are not present.
Bone density and local inflammatory processes influence the operative
protocol and the choice of the type of implant used in order to replace
the lost teeth and maxillary bone losses often require additional
Cone beam computerized tomography (CBCT) favors the obtaining of images
with lower radiation doses and reduced cost, due to its technology
capable of producing images with submillimetric isotropic spatial
resolution, and for that, it is indicated especially for the
A grafting material takes the role of substitute of the insufficient
bone tissue if it meets biocompatibility criteria, if it has an optimal
response to biomechanical stress and a great capacity to replace the
functions of synthesis/reshaping of the bone structure, essential for a
correct turnover and for a good functionality of the tissue.
In recent years, PRF concentrates have been widely used as a supplement
to tissue regeneration procedures.
For these reasons, the aim of the present study was to evaluate the
outcome of subjects with considerable sinus membrane pathology
undergoing maxillary sinus floor augmentation using Platelet Rich Fibrin
(PRF®) as a filling material, in association with the deproteinized
bovine bone (Bio-Oss®) and beta tricalcium phosphate (Sint-Oss®) and
simultaneous implant placement.
Materials and methods
Fifty-six patients (32 men, 24 women) in the age range of 55–73 years
(mean age, 64 years), who received a dental implant between June 2009
and June 2010, were selected from multicentric private practice dental
cabinets in Bari, Barletta, Carate Brianza, Milan, and Chieti.
In order to minimize the operator’s bias, surgical procedures were
performed by only two operators, maintaining the same equipment in all
performed surgical procedures.
The present study followed the rules established in the 1975 Declaration
of Helsinki, then revised in 1983. Before any treatments, the patients
were properly informed about the advantages and disadvantages of all the
planned procedures, first verbally and then with a written form for the
A total of 175 implants were placed in these patients. Patients were
included in the study according to the following criteria: (1) patients
having multiple consecutively edentulous space both in maxillary and
mandibular region and with compromised dental elements needing multiple
extractions; (2) adequate bone quantity and quality at the implant site;
(3) patients well motivated for implant therapy and maintaining good
Patients who were either non-compliant with appointments or had acute
sinusitis were excluded from the study prior the surgical procedure.
An X-ray orthopantomogram was performed before the surgical procedure
Patients were evaluated for sinus pathology for a period of 6–48 months
after bone transplantation and implant insertion using preoperative and
postoperative panoramic radiological imaging and CBCT scan for the
purposes of diagnosing their sinus pathology (Figure 2).
Furthermore, CT is employed in the diagnosis and follow-up of patients
who are candidates for,
or have been submitted to grafting techniques, which allows bone areas
to be evaluated by means of measurements and different densities with
Imaging was employed to monitor the progress of all patients.
The above CBCT scan examinations have shown that 26 patients of Group A
(Control Group) were not showing alterations of the anatomy and
physiology of the maxillary sinus, such as thickening of the Schneider
membrane or radiographic opacification which could suggest the presence
of an inflammatory process.
In the other 30 patients of Group B (Test Group), on the basis of the
radiographic findings, it was possible to hypothesize the presence of
opacification of the maxillary sinus.
All patients were questioned for complaints and symptoms of sinusitis
preoperatively, and any positive findings were assessed by an
otolaryngology consultation prior to the surgical procedure.
All the patients underwent a careful hematologic and cardiologic
evaluation (blood routine, cardiological examination, ECG) in specialist
wards to optimize and customize the prophylaxis and the preoperative
pharmacologic therapy (details shown in surgical procedure).
The bone loss was assessed by means of radiological investigations and
CBCT; the choice of implants was case-specific, according to the
rehabilitative necessity (Stone® -I.D.I.-EVOLUTION, Monza, Italy).
Before each surgical treatment, a full mouth disinfection protocol
consisting of scrupulous
oral hygiene was practiced by supragingival and subgingival scaling with
adjuncts of antimicrobial (chlorhexidine, CURASEPT 0,2%, Curadent,
Moreover, before surgery, the authors decided to administer per os
amoxicillin/clavulanic acid (NEODUPLAMOX, Procter & Gamble, Italy, of 2
g, 1 h before surgery and 1g 6h after surgery).
Preparation of PRF®
As reported from previous experience, the protocol is performed in
accordance with Choukroun’s procedure, introduced with the European
Directive no. 2004/23/CE of 31 March 2004.
The patients were subjected, before surgery, to complete hemogram
analysis. Before starting the surgical procedure, 5 mL of the patient’s
venous blood was drawn from the antecubital vein in a sterile 10 mL
glass test tube (free from anticoagulant) and centrifuged at 3000 rpm
for 10 min (Centrifugette model 4206, ALC International).
The upper straw-colored layer was then removed and the middle fraction
was collected, 2 mm below lower dividing line, which was the PRF.
This PRF was used in two ways: a part of it was included in a sterile
cup and mixed with Bio-Oss®/Sint-Oss®, until a homogeneous material is
obtained; the other part was divided into two sterile compresses, one of
which was modeled as a resistant fibrin membrane, transferable to the
Schneiderian membrane, and the other was transferred to the material
placed before closing the wound.
The authors opted for the surgical procedure of one-stage sinus lift
(implant insertion occurred concurrently with sinus lift, and the
healing and integration time was 6–9 months), except for eight selected
cases in which the height of the residual bone was lower than 5 mm.
After local and regional anesthesia administration (20 mg/mL mepivacaine
chloridrate CARBOPLYINA-Dentsply, Italy) containing adrenaline as a
vasoconstrictor (1:100,000), all patients underwent a lateral window
approach, in accordance with Tatum’s technique.
The crestal mucosa was incised and two release incisions were also made.
The muco-periosteal flap was then turned over in order to expose the
bone surface beneath.
The osteotomy to delimit the bone window was performed by Surgybone®
Piezosurgery (Silfradent Co., Sofia, Italy) (Figure 3) and the Valsalva
maneuver was performed to be sure of the membrane integrity.
The sinus membrane was carefully elevated from the sinus floor and
medial sinus wall; radiographic depth gauge was used to confirm that the
depth was correct.
PRF was used in combination with autogenous bone, an organic bone
material, and organic bone substitutes (Bio-Oss® and Sint-Oss®).
This mixture was inserted in the surgical alveolus by means of a syringe
or an amalgam carrier (Kavo Kerr Group, Italy), and pushed upwards with
the osteotome, in order to lift the Schneiderian membrane and keep clear
the first part of the implant bed (Figure 4), and at the end of this
stage, two membranes were placed.
They were obtained from the flattening of the remaining PRF between two
sterile gauzes and then placed in order to close the access area to the
At this phase, implants were inserted, and the length was in the range
of 2–4 mm in excess, compared to the height of the available bone.
Lastly, the bone window was closed to avoid traumatisms, the flap was
replaced and then the mucosal areas were sutured through a resorbable
During implant insertion, which had to be very slow, the filling
material displaced the Schneiderian membrane and was placed around the
implant, thus avoiding the collapse of the membrane on its surface.
At the end of surgery, an endoral periapical radiography with a
positioner was performed to assess the implant position compared to the
maxillary sinus and the implants did not make contact with the sinus
membrane in any of the patients.
In the eight patients in which the height of the residual bone was lower
than 5 mm, the fixture was inserted in a later stage (4 months after the
grafting procedure), in order to allow the stabilization and integration
of the grafted material, and then the restoration of an adequate bone
quantity to ensure the predictability and stability of implant
Patients were given postoperative instructions, and prescribed
antibiotics (amoxicillin/clavulanic acid 1000 mg every 12 h, for 7 days;
NEODUPLAMOX, Procter & Gamble, Italy), analgesics/anti-inflammatory
drugs (intramuscular injection of ARTROSILENE, Dompè SpA, Italy;
ketoprofen 160 mg, every 12 h for 5 days), and mouthwash with
clorexidine ( CURASEPT 0.12%, Curadent, Italy, every 12 h for 14 days).
Patients in Group B also received instructions for aerosol therapy
consisting of 2 mL of nebulized corticosteroid (hydrocortisone and
diprofillin, CORT-INAL, Teofarma SRL, Italy) and 500 mg/4 mL of
antibiotic (Thiamphenicol glycinate acetylcysteinate; FLUIMUCIL
ANT.IN.TOP, Zambon, Italy), twice per day for 10 days before and 10 days
Synthetic absorbable sterile surgical suture stitches (Vicryl® sizes
3.0–4.0) were removed after 7 days.
After implant placement, clinical parameters were recorded and evaluated
at baseline, 3, 6, 9, and 12 months. The clinical parameters recorded
were the modified plaque index, modified gingival index, probing depth
around the implant at four sites using the Tissue pressure sensitive
(TPS) probe, implant mobility according to clinical implant mobility
scale, and the absence or presence of any infection around the implant.
X-ray orthopantomogram and a second-level radiographic examinations
(Denta-Scan) were performed at 15, 60, 90, 120, and 180 days and 6, 12,
24, 36, and 48 months after surgery (Figures 5 and 6).
At the 1-year follow-up, patients were shown auxiliary cleaning methods
given that they had been instructed on how to brush in order to improve
A total of 175 dental implants were inserted in 56 patients (32 men, 24
women) between 2009 and 2010.
All procedures were successfully concluded without significant
procedural or postprocedural
complications or implant failure. Healing, in general, was uneventful
with minimal discomfort to all the patients. All the sites maintained
excellent peri-implant soft and hard tissue conditions.
In 30 patients with a pre-existing radiographic opacification which
could suggest the presence of an inflammatory process (54% of both
groups), the sinus pathology regressed or remained unchanged in 18
patients (32% in Group B), while in two patients in Group B the sinus
membrane pathology was limited to evaluation by periapical X-rays and in
six patients (11% in Group B) it completely disappeared as shown in CBCT
All the patients receiving the procedure reported a subjective
improvement of nasal breathing with increased perception of the air
From a clinical point of view, the authors noticed peri-implant tissue
healing, with a successful implant-prosthetic rehabilitation. All
patients reported no pain to percussion, no sign of tissue suffering to
the soft peri-implant tissues, and the presence of an optimal primary
stability of the inserted implants, as confirmed by the fulfillment of
Albrektsson’s implant success criteria The radiological examination,
performed after 6 months, revealed the presence of newly-formed bone
tissue, well amalgamated with the residual bone, and also showed an
average increase in the peri-implant bone density of 31% (Figures 5 and
In the apical region, the authors also noticed close contact of implants
with the newly-formed bone.
One year after loading there were no dropouts and no failure of the
definitive prosthesis occurred.
The basis of reduction of the volume of the maxillary sinus is
multifactorial and includes congenital and acquired variants; among the
latter are neoplastic, traumatic, iatrogenic, inflammatory, and systemic
Maxillary sinus grafting is a predictable and reliable procedure that
has been routinely performed for more than 30 years.
The complication rate is low, but some cases may require additional
surgery, and the outcome of oral rehabilitation may be affected.
The use of Piezosurgery involves considerable advantages for the oral
surgeon: an osteotomy with micrometric cut for complete surgical
accuracy and a high intraoperative sensibility; a site-specific
selective cut to minimize the damage to the soft tissues, which is an
important quality to preserve the sinus membrane while creating the
trans-cortical access window in sinus lift; and an excellent
intraoperative visibility thanks to a bloodless surgical field, ensured
by the effect of cavitation.
Both the measurements previously performed on radiograms and the tactile
sensation of contact with the cortical surface allowed the experienced
clinician to appreciate the contiguity with the sinus floor.
In the present study, even in cases where the surgery was considered
risky and not suitable for the presence of a clear pathological state of
departure that could affect the final result and exposure to a higher
risk of complications, there was full success in centering the objective
of regenerative bone therapy and the authors also performed the
collateral objective of no negative evolution in the sinusitis.
For this purpose, the choice of the ‘filling’ material represents an
essential aspect for a complete and real achievement of the
In fact, in recent years, various techniques have been proposed and
several types of materials have been assessed (autologous and
eterologous); these were critically reviewed by means of clinical
studies and histological investigations.
The continuous pursuit of the ideal filling material has often focused
the attention on the adoption and marketing of several bone substitutes,
such as autologous bone, demineralized and freeze-dried bone,
hydroxyapatite, and different combinations of these materials, often
with satisfactory results in terms of biocompatibility, induction of
bone formation, and of course, implant stability.
As a supplement to procedures of tissue regeneration, a platelet
concentrate called PRF was tested for the first time in France by
Choukroun et al. and introduced with the European Directive no.
2004/23/CE of 31 March 2004.
PRF belongs to a new generation of platelet concentrates; unlike
Platelet Rich Plasma (PRP), PRF is obtained without the addition of
anticoagulants such as heparin, EDTA, bovine thrombin, and so on.
During the production of PRF, apart from platelets, other cellular
elements are activated, such as leukocytes, which release cytokines
after the artificial hemostatic and inflammatory phenomenon induced by
There are, therefore, three pro-inflammatory cytokines (IL-1β, IL-6, and
TNFα), an anti-inflammatory cytokine (IL-4), and an angiogenesis
Hence, PRF is able to regulate inflammation and stimulate the immune
process of chemotaxis.
PRF is an autologous graft material that eliminates any risk of disease
transmission; besides, its gelatinous consistency enhances clotting and
However, it has an important defect: as it is a biomaterial directly
obtained from the patient’s blood, its quantity is modest. PRF has the
special feature to undergo polymerization during centrifugation,
naturally and slowly; active thrombin and fibrinogen concentrations are
almost physiological, because the material does not require any addition
of bovine thrombin.
As a result, the fibrin assumes a three-dimensional conformation, and
the combination of fibrin monomers leads to the formation of a
trimolecular structure, thus forming a soft and permeable mesh network
and allowing rapid colonization of the scar cells.
This natural material actually seems to accelerate the physiological
wound healing; besides, in association with bone grafts, it seems to
accelerate new bone formation.
Most of the authors who used PRF in their dental practice affirm that
there was no risk of infection, disease transmission, or side effects.
In this regard, a careful revision of literature on the possible effects
of the therapeutic use of growth factors (GFs) (including PRF), with
relation to carcinogenesis, to their influence on tissues with
epithelial dysplasia or oral carcinoma, and to their relation with
growth and tumor infiltration is absolutely necessary.
Besides, it is essential to underline that little is known about the
ideal concentration of each GF or the optimal dosage for each actual
therapeutic situation, and it seems that concentrated growth factor
(CGF) is similar to PRF and may be useful in the future to increase the
success rate of bone grafting.
In the present study, all patients participated until the end of the
study with no clinical dropout reported; all patients showed good
compliance in oral hygiene maintenance and followed other instructions
and no complications were recorded in any of the cases.
Furthermore, the use of PRF® and Piezosurgery reduced the healing time,
favoring optimal bone regeneration and allowing sinus membrane integrity
to be maintained during surgical procedures, according to evidence-based
In conclusion, the authors conclude by stressing the need to continue
this study on a wider cohort of patients, and to carry out large-scale
analyses which could provide statistically significant criteria about
the success of this procedure.
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect
to the research, authorship, and/or publication of this article.
This research received no specific grant from any funding agency in the
public, commercial, or not-for-profit sectors.
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