Maxillary sinus floor elevation usingthe (transalveolar) osteotome techniquewith or without grafting material.Part I: implant survival and patients’perception

Bjarni E. PjeturssonClaude RastUrs BraggerKurt SchmidlinMarcel ZwahlenNiklaus P. Lang

Authors’ affiliations:Bjarni E. Pjetursson, Faculty of Odontology,University of Iceland, Reykjavik, IcelandBjarni E. Pjetursson, Claude Rast, Urs Bragger,Niklaus P. Lang, University of Bern, School ofDental Medicine, Bern, SwitzerlandKurt Schmidlin, Marcel Zwahlen, ResearchSupport Unit, Institute of Social and PreventiveMedicine, University of Bern, Bern, SwitzerlandNiklaus P. Lang, Prince Philip Dental Hospital,University of Hong Kong, Hong Kong, SAR-PRC

Correspondence to:Bjarni E Pjetursson, DDS, Dr med. dent., MASDepartment of ProsthodonticsUniversity of IcelandVatnsmyrarvegur 16IS- 101 Reykjavik, IcelandTel.: þ 354 525 4850Fax: þ 354 525 4874e-mail: bep@hi.is

Key words: biological complications, bone augmentation, bone grafting, complications,

crestal approach, dental implants, failures, longitudinal, osteotome technique, patients’

perception, patients’ satisfaction, peri-implantitis, sinus augmentation, sinus floor eleva-

tion, sinus grafting, success, survival, transalveolar approach

Abstract

Objectives: To analyze the survival and success rates of implants installed utilizing the

(transalveolar) osteotome technique, to compare peri-implant soft tissue parameters and

marginal bone levels of osteotome-installed implants with implants placed using standard

surgical procedures, and to evaluate patient-centered outcomes.

Material and methods: During 2000 to 2005, 252 Straumanns

dental implants were

inserted in 181 patients. The surgical technique was a modification of the original

osteotome technique presented by Summers. In addition to the clinical examination, the

patients were asked to give their perception of the surgical procedure, utilizing a visual

analogue scale.

Results: The cumulative survival rate of the osteotome-installed implants after a mean

follow-up time of 3.2 years, was 97.4% (95% confidence intervals: 94.4–98.8%). From the

252 implants inserted, three were lost before loading and another three were lost in the

first and second year. According to residual bone height the survival was 91.3% for implant

sites with � 4 mm residual bone height, and 90% for sites with 4 mm and 5 mm, when

compared with that of 100% in sites with bone height of above 5 mm. According to implant

length the survival rates were 100% for 12 mm, 98.7% for 10 mm, 98.7% for 8 mm and only

47.6% for 6 mm implants. Soft tissue parameters (pocket probing depth, probing attach-

ment level, bleeding on probing and marginal bone levels) did not yield any differences

between the osteotome-installed and the conventionally placed implants. More than 90%

of the patients were satisfied with the implant therapy and would undergo similar therapy

again if necessary. The cost associated with implant therapy was considered to be justified.

Conclusion: In conclusion, the osteotome technique was a reliable method for implant

insertion in the posterior maxilla, especially at sites with 5 mm or more of preoperative

residual bone height and a relatively flat sinus floor.

Elevation of the maxillary sinus floor

was first reported by Boyne in the 1960s.

Fifteen years later, Boyne & James (1980)

reported on elevation of the maxillary sinus

floor in patients with large, pneumatized

sinus cavities as a preparation for the place-

ment of blade implants. A two-stage

procedure, was described where the max-

illary sinus was grafted using autogenous

particulate iliac bone at the first stage of

surgery. At the second stage of surgery,

after approximately 3 months, the blade

Date:Accepted 15 December 2008

To cite this article:Pjetursson BE, Rast C, Bragger U, Schmidlin K,Zwahlen M, Lang NP. Maxillary sinus floor elevationusing the (transalveolar) osteotome technique with orwithout grafting material. Part I: implant survival andpatients’ perception.Clin. Oral Impl. Res. 20, 2009; 667–676.doi: 10.1111/j.1600-0501.2009.01704.x

c� 2009 John Wiley & Sons A/S 667

implants were placed and later used to

support fixed or removable reconstructions

(Boyne & James 1980).

With time it became eminent that the

posterior maxillary region was often lim-

ited for standard implant placement, be-

cause the residual vertical bone height was

reduced. An elevation of the maxillary

sinus floor was thus one option in solving

this problem. Several surgical techniques

have been presented to enter the sinus

cavity, elevating the sinus membrane and

placing bone grafts. A transalveolar ap-

proach for sinus floor elevation with sub-

sequent placement of implants was first

suggested by Tatum (1986). Utilizing this

approach, a ‘socket former’ for the selected

implant sizes was used to prepare the im-

plant site. A ‘green-stick fracture’ of the

sinus floor was accomplished by hand tap-

ping the ‘socket former’ in a vertical direc-

tion. After preparation of the implant site,

a root-formed implant was placed and al-

lowed to heal in a submerged way.

Summers (1994) later described another

transalveolar approach, the osteotome

technique for sinus floor elevation, using

a set of osteotomes of varying diameters to

prepare the implant site. The concept in-

tended to increase the density of the soft,

Types III and IV (Lekholm & Zarb 1985)

maxillary bone resulting in better primary

stability of inserted dental implants. Bone

was conserved by the osteotome technique

because drilling was not performed.

The bone-added osteotome sinus floor

elevation (BAOSFE), also referred to as the

‘Summers technique,’ may be considered

more conservative and less invasive than

the conventional lateral approach of sinus

floor elevation. A small osteotomy is

made through the alveolar crest of the

edentulous ridge, at the inferior border of

the maxillary sinus. This intrusion osteot-

omy procedure elevates the sinus mem-

brane, thus resulting in a ‘tent’ effect.

This creates space for bone graft placement.

It should be noted that the bone grafts are

placed blindly into the space below the

sinus membrane. Hence, the main dis-

advantage of this technique is the un-

certainty of a possible perforation of the

Scheiderian sinus membrane. However, an

endoscopic study has revealed that the

sinus floor may be elevated up to 5 mm

without perforating the membrane (Engelke

& Deckwer 1997).

In a multicenter retrospective study

(Rosen et al. 1999) that evaluated the

application of the Summers technique in

the placement of 174 implants in 101

patients, the survival rate was 96%, when

residual bone height was 5 mm or more,

but dropped to 85.7%, when residual bone

height was 4 mm or less. From these data it

would appear that the residual bone height

had a significant influence on the outcome

of these procedures.

In a recent study, survival and success

rates of 588 implants placed in 323 con-

secutive patients with a residual bone

height ranging from 6 to 9 mm were eval-

uated. After a mean observation period of

5 years, the survival and success rates

were, 94.8% and 90.8%, respectively (Fer-

rigno et al. 2006). During the study period,

only 13 perforations of the Schneiderian

membrane were detected, resulting in a

perforation rate of only 2.2%. It was con-

cluded, that the installation of short im-

plants in conjunction with osteotome sinus

floor elevation was predictable and may

reduce the indications for more invasive

and complex procedures, such as the sinus

floor elevation by the lateral approach

(Ferrigno et al. 2006).

Moreover, a systematic review (Emmer-

ich et al. 2005) evaluated the effectiveness

of sinus floor elevation using osteotomes.

The inclusion criteria considered studies

that had more than 10 patients and at least

6 months of functional loading. Eight stu-

dies met these inclusion criteria. Within

the limits of such limited long-term data,

the reviewers concluded that the short-

term success rates were similar to success

rates of implants conventionally placed in

the partially edentulous patients (96% after

36 months). Long-term data on outcomes

(45 years) of implants placed with the

osteotome technique are still scarce. As

the database of this systematic review

was heterogeneous, no statistical analysis

was performed with regards to the different

surgical techniques, implant types and/or

grafting materials.

The aims of this prospective cohort study

were to analyze the survival and success

rates of implants installed utilizing the os-

teotome technique, to compare peri-implant

soft tissue parameters and marginal bone

levels of osteotome-installed to conven-

tionally placed implants and to evaluate

the patients’ perception of the treatment.

Material and methods

During the period of 2000–2005, 252 den-

tal implants were inserted in a group of

181 patients at the Department of Per-

iodontology and Fixed Prosthodontics,

University of Bern, Switzerland. These

patients presented with an edentulous

space in the posterior maxilla with reduced

residual bone height, thus making standard

implant placement impossible. One-third

(35%) of the patients had lost their teeth

due to periodontal diseases, 43% of pa-

tients had lost their teeth due to other

reasons like caries, trauma or endodontic

failures and the remaining 22% could not

recall the reason for their tooth loss. Before

implant insertion, the patients had been

treated for existing periodontal disease

according to a comprehensive treatment

strategy (Lang et al. 1998). The operators

were either Faculty members at the De-

partment of Periodontology and Fixed

Prosthodontics, University of Bern, or

postgraduate students in the Department

directly supervised by Faculty members.

In this prospective cohort study, the

survival of implants placed in conjunction

with sinus floor elevation using the osteo-

tome technique (test) was evaluated. The

incidence of biological complications was

also evaluated. Implants placed utilizing

standard surgical procedures, in the same

sextant or on the contra-lateral side served

as the control implants to compare peri-

implant soft tissue conditions and marginal

bone levels between test and control

implants. Patients’ perception on the im-

plant therapy was also assessed using a

visual analogue scale (VAS) questionning

method.

Surgical protocol

The surgical technique utilized was a mod-

ification of the original ‘Summers techni-

que’ (Summers 1994):

� Presurgical patient preparation included

rinsing with 0.1% chlorhexidine for

1 min.

� A local anesthesia was administered in

the buccal and palatal regions of the

surgical area.

� A mid-crestal incision with or without

releasing incision was made and a full-

thickness mucoperiosteal flap was

raised.

Pjetursson et al . Sinus floor elevation

668 | Clin. Oral Impl. Res. 20, 2009 / 667–676 c� 2009 John Wiley & Sons A/S

� With a surgical stent or a distance

indicator, the implant position was

marked on the alveolar crest with a

small round bur (+1.4 mm). After

locating the implant position, the open-

ing of the preparation was widened with

two sizes of round burs (+2.3 mm and

+3.1 mm).

� After confirming the distance from the

alveolar crest to the sinus floor, pilot

drills with diameters of 2.2 and 2.8 mm

were used in sequence to prepare the

implant site to a distance of approxi-

mately 2 mm below the sinus floor.

In soft Type IV bone with a residual

bone height of 5–6 mm, there was

usually no necessity to use the pilot

drills. It was sufficient to perforate the

cortical bone at the alveolar crest with

round burs.

� The first osteotome (Straumann Osteo-

tome Kits

, Straumann AG, Walden-

burg, Switzerland) (Fig. 1) used was a

small diameter (1.6 mm) tapered osteo-

tome. With light tapping, the osteo-

tome was pushed toward the compact

bone of the sinus floor. After reaching

the sinus floor, the osteotome was

pushed about 1 mm further with light

tapping in order to create a ‘greenstick’

fracture on the compact bone of the

sinus floor. A tapered osteotome with

small diameter was chosen to mini-

mize the force needed to fracture the

compact bone.

� The second osteotome used was also a

tapered osteotome, but with a larger

diameter (2.2 mm). This increased the

fracture area of the sinus floor. The

second osteotome was applied to the

same length as the first one.

� The third osteotome used was a

straight osteotome with a diameter of

2.8 mm or about 1 mm smaller than

that of the implant to be placed.

The decision to utilize grafting material

or not was made by the operator. Following

this, the continuation of the surgical pro-

cedures were dependent on whether or not

grafting material was to be placed.

Implant placement without grafting

material:

� Without applying grafting material, the

straight osteotome with a diameter of

2.8 mm was pushed further until it

penetrated the sinus floor.

� The last osteotome used had a form

and diameter suitable for the implant.

For a standard diameter 4.1 mm im-

plant, the final osteotome was a

straight osteotome with a diameter of

3.5 mm and for a wide-body 4.8 mm

implant, the last osteotome used was a

straight osteotome with a diameter of

4.2 mm.

� The final step before placing the im-

plant was to check for membrane

perforation and to check that the pre-

paration was patent to the planned

insertion depth. A depth gauge for the

relevant implant diameter was inserted

to the decided length (Fig. 2).

Implant placement with grafting mate-

rials

� If grafting materials were used, the

osteotomes were not supposed to enter

the sinus cavity per se. Before place-

ment of any grafting material, the sinus

membrane was tested for any perfora-

tions. This was done with the Valsalva

manoeuvre (nose blowing test). The

nostrils of the patient were closed

with the patient blowing against the

resistance. If air leaked through the

implant site, it has to be assumed that

the sinus membrane was perforated,

and no grafting material was placed

into the sinus cavity.

� If the sinus membrane was judged to be

intact, the preparation was filled with

deproteinized bovine bone mineral

(BioOsss

Geistlich Sons Ltd, Wolhu-

sen, Switzerland). The grafting material

was then slowly pushed into the sinus

cavity with the same (+2.8 mm)

straight osteotome. This procedure

was repeated several times.

� After the application of the grafting

material, the tip of the osteotome was

allowed to enter about 1 mm into the

maxillary sinus cavity to test for any

resistance in the preparation site and

finally, before implant placement, the

preparation was checked for patency, as

mentioned before, and the Valsalva

manoeuvre was repeated.

The postsurgical care after the implant

placement with the osteotome technique

was similar to that after standard implant

placement. In addition to the standard oral

home care, antiseptic rinsing with 0.1–0.2%

chlorhexidine twice daily for the first 3

weeks after surgery was recommended. In

cases where bone substitutes were used, the

patients were placed on antibiotic prophy-

laxis (Clamoxyls

750 mg three times daily)

for a period of 1 week (Glaxo-Smith-Kline

AG, Munchenbuchsee, Switzerland).Fig. 1. The Straumann Osteotome Kits

with a range of tapered and straight osteotomes.

Fig. 2. A depth gauge, for the relevant implant

diameter, was inserted to check the potency of

the osteotomy site and to decide on the implant

length.

Pjetursson et al . Sinus floor elevation

c� 2009 John Wiley & Sons A/S 669 | Clin. Oral Impl. Res. 20, 2009 / 667–676

Prosthetic procedure

After a healing period of 4–6 months,

impressions were taken. At impression-

taking or couple of weeks later, prosthetic

abutments were inserted with a 35 N cm

torque and reconstructions were issued.

The implants were used to support single

crowns (SCs), solely implant-supported

fixed dental prostheses (FDPs) (Fig. 3) and

combined tooth-implant-supported FDPs.

Clinical examination

At the annual clinical examination follow-

ing functional loading, the following clin-

ical parameters were evaluated:

� survival of implants and reconstruc-

tions.

� distance between the implant shoulder

and the mucosal margin (DIM) in

millimeters (recession scored as nega-

tive value) measured at six sites per

implant.

� pocket probing depth (PPD) in milli-

meters measured at six sites per

implant.

� probing attachment level (PAL) in

millimeters was calculated by subtract-

ing PPD from DIM.

� bleeding on probing (BOP) was mea-

sured at four sites per implant.

All soft tissue measurements were made

by one examiner with a UNC-15 perio-

dontal probe (Hu-Friedys

, Chicago, IL,

USA). Readings were made to the nearest

millimeter.

Radiographic examinations

Radiographs were taken using a Rinn film

holder (XCPs

Instruments, Rinn Corpora-

tion Elgin, IL, USA) with a rigid film-

object X-ray source. In order to perform

the measurements, the radiographs were

captured using a black and white video

camera (Canon, Still Video Products

Group, Tokyo, Japan) and viewed on a

light box. The images were transferred to

a computer and digitized with frame grab-

ber hardware (Matrox Electronic Systems

MVP/AT, Dorval, QC, Canada). Using

image-processing software, digitized images

were stored with a resolution of 512 �512 � 8 bit pixels (256 shades of gray).

Stored images were then displayed on a

monitor and linear measurements were per-

formed by two calibrated examiners with

the help of a cursor (Bragger et al. 1996).

The following measurement was made:

Marginal bone level – the distance from

the implant shoulder (S) to the alveolar

bone crest (AC) mesial and distal.

Patients’ perceptions

Before the clinical examination was per-

formed the patients were asked to give their

perception on the surgical procedure and

the implant therapy in general. The pa-

tients were also asked to evaluate nine

statements concerning general satisfaction,

chewing comfort, cost of therapy, pain and

discomfort during and after the surgical

procedure utilizing a VAS in which 0

indicated ‘total discontent’ and 100 ‘total

satisfaction.’

Statistiscal analysis

We provide descriptive statistical informa-

tion on baseline characteristics of patients

and implants: mean and standard deviation

(SD) or range for continuous characteristics

and percentage distribution for categorical

characteristics. For implant loss the unit

of analysis was the implant. We provide

cumulative survival or cumulative inci-

dence estimates and their 95% confidence

intervals (CI) derived from Kaplan–Meier

calculations (Kaplan & Meier 1958). We

calculated separate 3-year survival esti-

mates according to implant length and

residual bone height categories.

To formally compare mean probing

pocket depth (PPD) (mm), mean probing

attachment levels (mm) and mean BOP

(%) between osteotome and standard im-

plants we fitted multilevel linear regression

models which account for the fact that the

measurements at the same implant and in

the same patient are correlated to some

degree. We report P-values for the mean

difference between osteotome and standard

implants from these models.

For the comparison between osteotome

and standard of categories of PPD and

categories of marginal bone levels we fitted

multilevel logistic regression models and

report the overall P-value derived from

these models. In situations where observa-

tions are not nested and correlated within

levels, these P-values correspond exactly to

P-values derived from the w2 statistics used

for testing differences in categorical vari-

able. In our situation these models allow to

account for the correlated nature of the

measurements within patient and implant.

All analyses were conducted using Stata

version 10 (Stata Corporation, College

Station, TX, USA).

Results

Over the 6-year period (2000–2005), 181

patients with mean age of 54.9 (range 17–

90) years at the time of implant insertion,

were included in the study. The patients

were medically healthy. Fort-one percent

of the patients were non-smokers, 39%

were former smokers and the remaining

36 patients or 20% were smokers. Sixteen

of the smokers, smoked o10 cigarettes per

day, 19 smoked between 10 and 20 cigar-

ettes per day and one was a heavy smoker,

smoking 420 cigarettes per day.

These 181 patients received 252 im-

plants placed in conjunction with maxil-

lary sinus floor elevation using the

osteotome technique (test). For 109 of

these osteotome-installed implants, im-

plants placed in the same sextant or on

the contra-lateral side using standard surgi-

cal procedures served as controls. All

implants were Straumanns

solid screw

implants. The majority of those (60%)

were standard implants with a diameter of

4.1 mm, 35% were wide-body implants

with a diameter of 4.8 mm and the remain-

ing 5% were implants with a reduced

diameter of 3.3 mm. The most frequently

used (62%) implant length was 8 mm fol-

lowed by 10 mm implants that were used

in 31% of the cases. Long 12 mm implants

and short 6 mm implants were used only in

4% and 3% of the cases, respectively.

Forty-six percent of the implant placed

with the osteotome technique were placed

in the position of the second premolar. The

second most common position was the

first molar with 35%, and the third most

common position was the first premolar

with 14% of the implants. Only 5% of the

Fig. 3. A four-unit fixed dental prosthesis supported

by three implants. The implants in positions 24 and

26 were installed with the osteotome technique.

Pjetursson et al . Sinus floor elevation

670 | Clin. Oral Impl. Res. 20, 2009 / 667–676 c� 2009 John Wiley & Sons A/S

implants were placed in the position of

second molars or canines (Fig. 4).

The residual bone height was on average

7.5 mm (SD 2.2 mm) and the apices of the

implants penetrated on average 3.1 mm

(SD 1.7 mm) into the sinus cavity. During

the implant site preparation, membrane

perforations diagnosed by the Valsalva

manoeuvre were detected in 10.4% of the

sites. Two-thirds (65%) of the osteotome-

installed implants were placed without

utilizing grafting material. In the remaining

35%, deproteinized bovine bone mineral

(BioOsss

Geistlich Sons Ltd) was used as

the sinus grafting material.

Survival and failure rates

With the exception of four patients who

experienced excessive hematoma after

surgery, wound healing was uneventful.

Eighteen patients with 18 implants that

only received the implants at the at the

Department of Periodontology and Fixed

Prosthodontics, University of Bern, but the

implant-supported reconstructions were

made by the referring dentist, did not

participate in the follow-up.

The cumulative survival rate of the os-

teotome implants after a mean follow-up

time of 3.2 years, was 97.4% (95% CI:

94.4–98.8%) (Table 1, Fig. 5).

From the original 252 implants inserted,

three implants were lost before loading.

In one case, an 8 mm diameter implant

was inserted without grafting material in

position of tooth 25 in a fully edentulous

patient. The residual bone height was

5 mm. After 6 weeks, the implant became

loose and was removed. The reason for the

implant loss was probably due to the pres-

sure of the provisional removable dental

prosthesis on the implant site during the

early-healing phase. Ten weeks after the

implant was removed a second 8 mm im-

plant was placed and grafting material was

utilized. The healing was uneventful and

the implant was later used as an abutment

to support a 3-unit FDP.

The second implant that was lost before

loading was a short 6 mm diameter implant

placed without grafting material in a site

with a mean residual bone height of 5 mm

(7 mm mesial and 3 mm distal). The im-

plant did not osseointegrate and was re-

moved after 8 weeks. Again, the patient

was wearing a provisional removable dental

prosthesis during the healing period. The

third implant lost before loading was a

10 mm diameter implant placed in position

of tooth 25, in a site with 5 mm residual

bone height. At abutment connection, at

10 weeks postimplant insertion, the im-

plant was not stable and rotated (spinner).

Despite, a prolonged healing time of an-

other 10 weeks the implant did not become

stable and was finally removed after 5

months. The remaining 249 implants

were followed for a mean period of 3.2

years (range 1–7 years). Three additional

implants were lost during the follow-up

time. Two of these patients had received

short 6 mm implants placed in sites with a

residual bone height of only 3–4 mm with-

out utilizing any grafting material. One of

those implants was used as an abutment

for a 4-unit FDP (16XX13). After a loading

time of 6 months, the patient heard a

‘crack sound’ and felt pain in the anterior

implant (region 13). A couple of weeks

later, the bridge together with the 6 mm

implant was lost (Fig. 6). Subsequently, a

two-stage sinus floor elevation was per-

formed using the lateral approach, and

0

20

40

60

Fre

quen

cy

16 15 14 13 23 24 25 26 27Osteotome implant region

Distribution of osteotome implants in the maxilla

Fig. 4. Distribution of implant position in the maxilla.

Table 1. Cumulative implant survival

Time(years)

Number ofimplants

Implantslost

Survivorfunction

95% CI

1 234 3 0.988 0.963–0.9962 200 2 0.979 0.951–0.9913 144 1 0.974 0.944–0.9884 74 0 0.974 0.944–0.9885 38 0 0.974 0.944–0.9886 13 0 0.974 0.944–0.9887 2 0 0.974 0.944–0.988

CI, confidence interval.

0.00

0.25

0.50

0.75

1.00

Sur

viva

l pro

port

ion

0 2 4 6 8Time

Implant Survival

Fig. 5. Implant survival.

Pjetursson et al . Sinus floor elevation

c� 2009 John Wiley & Sons A/S 671 | Clin. Oral Impl. Res. 20, 2009 / 667–676

two new implants were inserted. For the

second patient, a short 6 mm implant was

lost after a follow-up period of 18 months.

The third patient who lost an implant

in function was the only heavy smoker. He

received two implants in positions 16 and

26 using the osteotome technique. The

residual bone height was between 4 and

5 mm and grafting material was used to

elevate the sinus floor. After 6 months, the

implant in position of tooth 26 had a

diagnosis of peri-implantits with substantial

marginal bone loss. The peri-implantitis

was treated according to the implant main-

tenance and treatment protocol cumulative

interceptive supportive therapy (CIST)

(Lang et al. 2000). The implant, neverthe-

less, became mobile and was removed

3 months later.

According to the implant length, the

survival rates were 100% for 12 mm im-

plants, 98.7% for 10 mm implants, 98.7%

for 8 mm implants and only 47.6% for the

short 6 mm implants (Table 2).

According to residual bone height, the

survival rates were 91.3% for implant sites

with � 4 mm residual bone height and

90% for sites with residual bone height

between 4 and 5 mm, compared with a

survival rate of 100% if the residual bone

height was above 5 mm (Table 3).

Peri-implant soft tissue conditions

One-hundred and nine osteotome-installed

implants (test) were compared with 109

implants placed with standard surgical pro-

cedures (control).

The mean PPD of the test implants was

3.44 compared with 3.51 mm for the con-

trol implants (Table 4). In a frequency

analysis, the majority (83.1%) of the im-

plant sites had a PPD of 1–4 mm, 11.9% of

the sites had a PPD of 5 mm, and the

remaining 5% had a PPD of 6 mm or

more (Table 5). When the frequency analysis

of the PPDs (P¼has changed now:0.999)

and the mean PPDs (P¼ 0.364) were com-

pared, there were no significant differences

between the test and control implants.

The mean PAL of the test implants was

2.47 mm compared with 2.04 mm for the

control implants (Table 4). Moreover, 49%

of the sites around the osteotome-installed

implants BOP positive compared with 51%

for the control implants (Table 4).

When peri-implantitis was defined as

sites with PPD � 5 mm and BOP positive

(Mombelli & Lang 1994), 11.5% of the

sites and 40% of the examined implants had

peri-implantitis. On the other hand, when

the threshold was set at PPD � 6 mm and

BOP positive (Mombelli & Lang 1994), the

number of sites with peri-implantitis was

reduced to 3.7% and the number of im-

plants to 13.8%. With regards to the in-

cidence of peri-implantitis, there was no

significant difference between test and con-

trol implants. At the time of the final

clinical examination, 3% of the implants

had already been treated according the to

the CIST protocol (Lang et al. 2000).

Fig. 6. A short implant that supported a four-unit fixed dental prostheses became loose after a loading time of 6

months and the whole bridge together with the 6 mm implant was lost.

Table 2. The 3-year survival rates according to implant lengths

Implantlength (mm)

Number ofimplants

Implantslost

Survivalrate (%)

95% CI

6 7 3 47.6 0.075 0.8098 157 2 98.7 0.948 0.99710 77 1 98.7 0.911 0.99812 9 0 100 0.717 1

CI, confidence interval.

Table 3. The 3-year survival rates according to residual alveolar bone height

Residualboneheight (mm)

Number ofimplants

Implantslost

Survivalrate (%)

95% CI

� 4 24 2 91.3 0.695 0.9784–5 20 2 90 0.656 0.9745–6 34 0 100 0.916 16–7 39 0 100 0.926 1

� 7 103 0 100 0.971 1

CI, confidence interval.

Table 4. Mean probing pocket depths, probing attachment levels, marginal bone levelsand bleeding on probing

Osteotomeimplants

Standardimplants

P-valuen

Mean SD Mean SD

Mean probing pocket depth (mm) 3.44 1.13 3.51 1.11 0.364Mean probing attachment levels (mm) 2.47 1.05 2.04 0.98 0.185Mean bleeding on probing (%) 49.1 32.1 50.2 29 0.744Mean marginal bone levels (mm) 2.67 0.96 2.75 0.95 .29

nDerived from multilevel linear regression.

SD, standard deviation.

Pjetursson et al . Sinus floor elevation

672 | Clin. Oral Impl. Res. 20, 2009 / 667–676 c� 2009 John Wiley & Sons A/S

Radiographic examinations

Linear measurements to evaluate the mar-

ginal bone levels were performed on digi-

tized images. With the help of a cursor, the

marginal bone level [the distance from

implant shoulder (IS) to the first bone-to-

implant contact (BIC)] was measured. The

mean marginal bone level of the test im-

plants was 2.67 (SD 0.95 mm) compared

with 2.75 mm (SD 0.95 mm) for the con-

trol implants (Table 4). Performing a fre-

quency analysis, the 62.9% of the implants

showed stable bone levels, 28.3% of the

implants had marginal bone levels 0–1 mm

below the expected marginal bone level for

Straumanns

implants, 7.1% of the im-

plants had marginal bone levels 1–2 mm

below and 1.7% of the implants had sig-

nificant (42 mm) bone loss (Table 6).

When comparing marginal bone levels of

the test and control implants, there was no

significant difference, both in the fre-

quency analysis (P¼ 0.200) as well as in

the mean values (P¼ 0.290).

Patient-centered outcomes

The 163 patients examined at the follow-

up were asked to express their opinion

about nine statements. The first two state-

ments dealt with general satisfaction with

the treatment. The patients were asked if

they would undergo similar treatment

again if needed; On the VAS, the mean

VAS score was 91� 17. The median was

98 (range 0–100) (Fig. 7). Moreover,

the patients were asked if they would

recommend this treatment to a friend

or relative, if indicated. On the VAS, the

mean VAS score was 90� 17. The med-

ian was 97 (range 0–100). For both state-

ments only 5% or 3% of the patients

would not be willing to undergo such a

treatment again, respectively.

The third statement addressed the cost

for implant therapy. The cost of implant

therapy was also deemed to be reasonable

to a large extent. On the VAS, the mean

VAS score was 78� 22. The median was

84 (range 0–100) (Fig. 8).

The fourth statement compared the

chewing comfort of teeth with that of

implants. 22.2% felt more secure when

masticating on teeth, 60.2% perceived no

difference and 17.6% preferred masticating

on implants. The mean VAS score was

52� 28. The median was 50 (range 0–

100). The patients, who felt comfortable

when masticating on implant-supported

reconstruction were also asked about the

time it took to adjust to masticating on the

implant-supported reconstruction. Fifty-

two percent of the patients answered ‘im-

mediately,’ 28% answered 1 month, 13%

answered 3 months and the remaining 6%

stated that it took at least 6 months be-

fore they could adjust to their new recon-

structions. The remaining five statements

addressed the surgical procedure. Approxi-

mately 23% of the patients found the surgi-

cal experience unpleasant (Fig. 9). Upon

asking about other surgical complications,

Table 5. Frequency analysis of the probing pocket depth around test and control implants

Probing pocketdepth (PPD) (mm)

All implants(%)

Osteotomeimplants (%)

Standardimplants (%)

P valuen

1–3 59.6 62.8 56.3 0.9994 23.5 20.9 26.15 11.9 11.5 12.46 3.8 3.4 4.3

�7 1.2 1.4 0.9

nDerived from multilevel linear regression.

Table 6. Frequency analysis of the marginal bone levels around test and control implants

Marginal bonelevels (mm)

All implants(%)

Osteotomeimplants (%)

Standardimplants (%)

P valuen

0–3 62.9 66.3 59.4 0.23–4 28.3 26.8 29.74–5 7.1 4.6 9.7

�5 1.7 2.3 1.2

nDerived from multilevel linear regression.

0

20

40

60

80

100

Fre

quen

cy

0–9.9 10–19.9 20–29.9 30–39.9 40–49.9 50–59.9 60–69.9 70–79.9 80–89.9 90–100

Willingness for Retreatment

Fig. 7. Visual analogue scale for willingness to, undergo the treatment again if needed.

0

20

40

60

Fre

quen

cy

0–9.9 10–19.9 20–29.9 30–39.9 40–49.9 50–59.9 60–69.9 70–79.9 80–89.9 90–100

Costs Appropriate

Fig. 8. Visual analogue scale for cost of implant therapy.

Pjetursson et al . Sinus floor elevation

c� 2009 John Wiley & Sons A/S 673 | Clin. Oral Impl. Res. 20, 2009 / 667–676

5% of the patients felt their head was tilted

too far back during the surgery, 5% of the

patients experienced vertigo, nausea and

felt disoriented after the surgical procedure,

but no patient had any problem with unu-

sual eye movements. A small group of five

patients had psychological problems after

the treatment and had to seek medical

assistance.

Discussion

This study has demonstrated that from

the originally 252 implants inserted, 1.3%

were lost before loading. In the first and

second year of function, an additional 1.3%

of the implants were lost, resulting in a

cumulative survival rate of 97.4% for im-

plants placed with the osteotome techni-

que after a mean follow-up time of 3.2

years. These implant losses before func-

tional loading and the annual failure rate

were similar to those reported in systema-

tic reviews on conventionally inserted im-

plants (Lang et al. 2004; Pjetursson et al.

2004; Jung et al. 2008). These survival

rates are also in agreement with previous

studies (Bruschi et al. 1998; Zitzmann &

Scharer 1998; Rosen et al. 1999; Deporter

et al. 2005) reporting on implants inserted

using the transalveolar osteotome techni-

que. Furthermore, a systematic review by

Emmerich et al. (2005) concluded that the

short-term survival rates of osteotome-

installed implants was 96%.

During the entire implant site prepara-

tion, it was crucial to maintain a pre-

cise control of the penetration length of

the osteotomes. These should just pene-

trate through the sinus floor without

entering the sinus cavity. Following dis-

placement of the sinus floor, the grafting

material that was introduced elevated the

Schneiderian membrane without the in-

struments entering the sinus cavity.

Regular osteotomes have sharp cutting

edges. Thus, entry into the sinus cavity

with the tip of the instrument would in-

crease the risk of membrane perforation. In

the present study, membrane perforation

with 10%, was the most common compli-

cation using the osteotome technique. In

cases in which a membrane perforation was

noted, no grafting material was placed.

These complications, however, did not

influence the integration of the implants.

In all such cases the implants were stable

and could be used as abutments for im-

plant-supported reconstructions.

Morphological features such as an obli-

que sinus floor (4451 inclination) may

affect the treatment outcome. This does

not provide a suitable situation for utilizing

the osteotome technique (Fig. 10). The

reason for this lies within the geometry of

the penetration of the osteotome that will

first enter the sinus cavity at the lower

level of an oblique sinus floor, while still

having bone resistance on the higher level.

Consequently, there will be a higher risk

for perforating the Schneiderian membrane

with the sharp margins of the osteotome.

It has to be realized that the final osteo-

tome should enter the preparation site only

once. If is the largest osteotome is used

several times to introduce the grafting ma-

terial into the sinus cavity or if several

attempts were performed to prepare the

site with the largest osteotome, there is a

high risk of increasing the diameter of the

preparations in sites with Type III or Type

IV bone. Hence, this may jeopardize

achieving primary stability of the implants.

On the other hand, if the last osteotome

diameter is too small compared with the

implant diameter, too much torque will

be used when inserting the implant. Ex-

cessive compression of the bone results in

more trauma to the bone and hence, greater

bone resorption may be encountered. This,

in turn, may delay the osseointegration

process (Abrahamsson et al. 2004). When

placing implants in sites with reduced bone

volume, it is important to keep a fine

balance between primary stability and

minimizing trauma to the bone.

In the present study, no attempts were

made to optimize the outcomes by using

strict exclusion criteria. Hence, periodontal

patients, smokers, patients with parafunc-

tional habits and patients wearing remova-

ble provisional reconstructions were also

included. The only inclusion criterion was

that the patients were in good general

health and were treated for existing perio-

dontal diseases and rampant caries accord-

ing to a comprehensive treatment strategy

before implant insertion (Lang et al. 1998).

Moreover, no restrictions were made re-

garding the minimal preoperative bone

height. The decision on whether or not

the osteotome technique was suitable,

was made individually by each Faculty

member.

Regarding existing residual bone height,

20% of the implants in the present study

were placed in sites with residual bone

height of � 5 mm. This, in turn, means

that the limit of the osteotome technique

was indeed tested. It was evident that the

failure rates of the osteotome-installed im-

plants increased in correlation to reduced

0

10

20

30

40

Fre

quen

cy

0–9.9 10–19.9 20–29.9 30–39.9 40–49.9 50–59.9 60–69.9 70–79.9 80–89.9 90–100

Intervention Unpleasant

Fig. 9. Visual analogue scale of the unpleasantness of the surgical experience.

Fig. 10. Radiograph showing an oblique sinus floor

(4451 inclination), where the osteotome technique

is not suitable due to a high risk of membrane

perforation.

Pjetursson et al . Sinus floor elevation

674 | Clin. Oral Impl. Res. 20, 2009 / 667–676 c� 2009 John Wiley & Sons A/S

residual bone height and reduced implant

length. No implants were lost if the resi-

dual bone height was 45 mm, compared

with a failure rate of approximately 10% if

the residual bone height was o5 mm.

Moreover, for short 6 mm implants the

survival rate was only 48%. This clearly

demonstrated that the transalveolar sinus

floor elevation technique was most predic-

able with residual alveolar bone height of

5 mm or more and with implants of 8 mm

or more.

Moreover, peri-implant soft tissue para-

meters and marginal bone levels around the

osteotome-installed implants (test) were

compared with those parameters around

implants placed with standard surgical pro-

cedures (control). Such a comparison has

previously not been reported. There were

no statistically significant differences be-

tween test and control implants regarding

either PPD, probing attachment levels,

percentage of sites that bled on probing

and marginal bone levels. In the present

study, the prevalence of peri-implantitis

did not differ between the test and control

implants either. However, the prevalence

of peri-implantitis was influenced by the

threshold chosen for the definition of peri-

implantitis. When peri-implantitis was de-

fined as PPD � 5 mm and BOP-positive

sites, 40% of the examined implants had at

least one site with peri-implantitis. When

the definition was limited to PPD � 6 mm

and BOP positive, the percentage of im-

plants with at least one site with peri-

implantitis was reduced to 13.8%. This

high incidence of peri-implantitis can, at

least partly, be explained by the fact that

when implants are placed in edentulous

spaces with reduced bone height in the

positions of first or second premolar or

the first molar in the maxilla, the bone

levels on the adjacent teeth are often more

coronal that the alveolar crest in the eden-

tulous space (Fig. 11). This unequal level in

the alveolar bone may have lead to an

increased PPD mesial to those implants.

Because the prevalence of implants with

progressive bone loss (42 mm) was only

1.7% in the present study, such pockets

may be considered as ‘pseudopockets.’

From a total of 163 questionnaires dis-

tributed, questionnaires were completed

with rates varying between 94 and 100%.

This, in turn, reflected a reliable and accu-

rate subjective assessment of the implant

therapy with a high objective treatment

outcome.

When comparing the chewing function

on teeth and implants, 60% of the patients

revealed no preference. Twenty-two per-

cent of the patients felt more comfortable

when masticating on teeth and surpris-

ingly, 18% felt more comfortable when

masticating on implant-supported recon-

structions. In the present study, over 80%

of the patients confirmed that it took them

o1 month to adapt to the implant recon-

struction, following which the implant

contacts felt like ‘natural’ teeth.

Even though 23% of the patients re-

ported the surgical procedure as unpleasant,

490% of the patients would be willing to

undergo implant therapy again if necessary

and dentally indicated. Only five out of the

163 patients assessed the VAS at the lower

units, indicating a lack of willingness to

undergo the same implant therapy again.

In the present study, a small group of

5 patients had psychological problems

after the treatment and, therefore, had to

seek medical assistance. It must be rea-

lized, however, that the most difficult

patients to treat are patients with high or

unrealistic expectations for both implant

therapy in general as well as the osteotome

technique in particular. The proportion of

such patients in the present study pointed

to the fact that the psychological aspects

associated with such treatment are not to

be underestimated.

In conclusion, the transalveolar osteo-

tome technique was demonstrated to re-

present a reliable and predictable method

for implant insertion in the posterior max-

illa, at sites with 5 mm or more preopera-

tive residual bone height and a relatively

flat sinus floor.

Soft tissue parameters, such as PPD,

PAL and BOP and marginal bone levels

did not differ between the osteotome-

installed implants and conventionally

placed implants.

More than 90% of the patients were

satisfied with the implant therapy per-

formed and would be willing to undergo

such therapy again if necessary. The cost

associated with implant therapy was also

considered to be justified. Because the pre-

sent study covered a mean observation

period of 3.2 years following implant in-

stallation, there is still a need for long-term

clinical documentation (45 years) of the

outcomes of implants installed transalveo-

lar utilizing the osteotome technique.

Acknowledgements: This study has

been supported by the Clinical

Research Foundation (CRF) for the

promotion of oral health, University of

Bern, Switzerland.

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676 | Clin. Oral Impl. Res. 20, 2009 / 667–676 c� 2009 John Wiley & Sons A/S

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