clinical oral implants research_dr buser
DESCRIPTION
Early loading of titanium dental implants with intra-opratively conditioned hydrophilic implant surface after 21 days of healingTRANSCRIPT
Stefan Paul HicklinEsther SchneebeliVivianne ChappuisSimone Francesco MarcoJannerDaniel BuserUrs Br€agger
Early loading of titanium dentalimplants with an intra-operativelyconditioned hydrophilic implantsurface after 21 days of healing
Authors’ affiliations:Stefan Paul Hicklin, Esther Schneebeli, UrsBr€agger, Department of Reconstructive Dentistryand Gerodontology, School of Dental Medicine,University of Bern, Bern, SwitzerlandStefan Paul Hicklin, Division of FixedProsthodontics and Biomaterials, School of DentalMedicine, University of Geneva, Geneva,SwitzerlandVivianne Chappuis, Simone Francesco MarcoJanner, Daniel Buser, Department of Oral Surgeryand Stomatology, School of Dental Medicine,University of Bern, Bern, Switzerland
Corresponding authorDr med. dent. Stefan HicklinDepartment of Reconstructive Dentistry andGerodontologySchool of Dental MedicineUniversity of BernFreiburgstrasse 73010 BernSwitzerlandTel.: +41 31 632 99 94Fax: +41 31 632 49 31e-mail: [email protected]
Key words: dental implants, early loading, hydrophilic implant surface, late implant
placement
Abstract
Objectives: The aim of the present observational medical device performance study was to test
whether implants with an intra-operatively conditioned hydrophilic surface can be safely
reconstructed when applying an early loading protocol after 21 days in partially edentulous
posterior mandibles.
Material and methods: Partially edentulous patients with missing teeth in the posterior mandible
were recruited. Immediately after implant placement, the implant position was indexed using a
pickup impression technique. ISQ values were measured after 21 days of healing. When ISQ values
were ≥70, the implants were directly restored with provisional reconstructions in occlusal contact
allowing an early loading protocol. ISQ values were repeated again at 1, 3, and 6 months
postloading. Clinical parameters (mPLI, mSBI, PPD, DIM, and CAL) were assessed. Standardized
periapical radiographs were obtained after surgery, at implant loading and 3 and 6 months later.
Changes over time were analyzed for statistical significance using the nonparametric method by
Brunner & Langer (SAS Proc Mixed).
Results: Fifteen partially edentulous patients with healed sites in the posterior mandible received
20 implants. All implants healed uneventfully. At 21 days, all implants achieved an ISQ value of ≥70
(mean of 3 measurements) and were reconstructed at this time point with provisionals. ISQ values
showed a gradual increase from baseline to 3 and 6 months postloading. The assessment of clinical
parameters revealed stable tissue integration. The evaluation of the radiographs showed that 3
and 6 months after loading the median mesial and distal marginal bone levels had stabilized at
the border between the rough surface and the 1-mm machined implant collar.
Conclusion: Functional occlusal loading of implants with a hydrophilic, moderately rough
endosseal surface 3 weeks after placement appears to be a safe and predictable treatment option
in healed sites in the posterior mandible without need of bone augmentation procedures.
Implant therapy in partially edentulous
patients is a widely accepted treatment
modality today and often represents the first
choice to reestablish masticatory function,
phonetics, and esthetics. A recent 20-year
prospective case series study in partially
edentulous patients using coated titanium
plasma-sprayed (TPS) implants showed a
failure rate of 10.5% (Chappuis et al. 2013).
In the early 1990s, significant progress was
made in titanium surface technology based
on preclinical studies. Various techniques
have been employed to produce microrough
titanium surfaces, including sandblasting,
acid-etching, or combinations thereof in order
to modify surface topography (Wennerberg
et al. 1996). Among these new surfaces, the
sandblasted with large grits and acid-etched
(SLA) surface (SLA�, Straumann, Basel,
Switzerland) demonstrated enhanced bone
apposition in histomorphometric studies
(Buser et al. 1991; Cochran et al. 1998) and
higher removal torque values in biomedical
testing (Wilke et al. 1990; Buser et al. 1998).
Based on these experimental results, clinical
studies were initiated to restore SLA
implants (SLA�; Straumann, Basel, Switzer-
land) with an early loading concept after 6 to
Date:Accepted 31 August 2015
To cite this article:Hicklin SP, Schneebeli E, Chappuis V, Janner SFM, Buser D,Br€agger U. Early loading of titanium dental implants with anintra-operatively conditioned hydrophilic implant surfaceafter 21 days of healing.Clin. Oral Impl. Res. 00, 2015; 1–9.doi: 10.1111/clr.12706
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd 1
8 weeks (Roccuzzo et al. 2001; Cochran et al.
2002). Today, 10-year studies are available
documenting favorable long-term success
rates of SLA implants (SLA�; Straumann)
(Buser et al. 2012; Fischer & Stenberg 2012;
van Velzen et al. 2015; Wittneben et al.
2014).
In the early 2000s, researchers started to
focus on surface chemistry as another key
factor for peri-implant bone apposition, as it
influences surface charge and wettability.
Surface wettability is largely dependent on
surface energy and influences the degree of
contact with the physiologic environment
during early healing events (Textor et al.
2001). Preclinical studies testing hydrophilic
SLA implants (SLActive�; Straumann)
demonstrated an even faster bone apposition
and increased removal torque values during
initial wound healing when compared with
the hydrophobic SLA implant surface (SLA�;
Straumann) (Buser et al. 2004; Ferguson et al.
2006). Subsequently, the healing phase in
patients was further reduced to 21 days
demonstrating high success rates up to
3 years of follow-up (Bornstein et al. 2009,
2010; Morton et al. 2010).
Implants with a new alternative hydrophi-
lic surface (SPI� ELEMENT INICELL�,
Thommen Medical AG, Grenchen, Switzer-
land) have also been tested in previous pre-
liminary clinical trials providing
documentation of a favorable performance
and reliability (Held et al. 2013; Merli et al.
2013; Hinkle et al. 2014). The new hydrophi-
lic, moderately rough surface (SPI� ELE-
MENT INICELL�; Thommen Medical)
represents a chemical modification of an
already approved sandblasted and thermally
acid-etched surface (TST SPI� ELEMENT;
Thommen Medical AG) (Chenaux et al.
2008), that is, the physical macro- and
microstructure of the surface remained
unchanged. Conditioning consists of a purely
chemical process that increases the wettabil-
ity of the surface. In this way, all the impor-
tant clinical characteristics remain
unchanged. Already with the unchanged sur-
face (TST SPI� ELEMENT, Thommen Medi-
cal AG), early loading protocols had been
tested (Merli et al. 2008, 2012). Impressions
have been taken at 6 weeks, and the provi-
sional were taken out of occlusion. Compared
to conventional loading, similar results had
been obtained in partially edentulous patients
and with flapless surgical interventions.
The aim of the present observational medi-
cal device performance study was to test the
hydrophilic implant surface (SPI� ELEMENT
INICELL�, Thommen Medical AG) with a
21-day loading protocol in partially edentu-
lous patients with implant sites in the
posterior mandible. The provisional single
crowns or FPD were to be inserted with at
least one occlusal contact.
Material and methods
Patient selection
This prospective observational medical
device performance study was conducted in
full accordance with ethical principles,
including the Declaration of Helsinki. The
ethical committee for clinical studies Canton
of Bern (Switzerland) approved the study
prior to the start (approval number: 118/10).
The original aim was to recruit at least 30
patients in need of 50 implants in this
study. Finally, 15 partially edentulous
patients gave a written informed consent
according to the above-mentioned principles.
All patients were treated at the School of
Dental Medicine, University of Bern. An
initial examination was conducted at least
1 day prior to implant placement to deter-
mine whether the patient met the inclusion
criteria. The clinical and radiographic exami-
nation included all routinely used assess-
ments for a safe implant treatment. Alginate
impressions and bite registration were taken
in the upper and lower jaw for implant
planning and fabrication of a surgical stent.
Enrollees were patients in good health condi-
tions (PS1 and PS2, according to Physical
Status Classification System of the American
Society of Anesthesiologists). Recruited were
18 to 75 years old, partially edentulous
patients with missing teeth in the posterior
mandible (positions 34–37 and 44–47), requir-
ing a fixed implant-supported reconstruction.
Excluded from study participation were
women of childbearing potential with a posi-
tive urine pregnancy test, patients with inad-
equate oral hygiene or persistent intra-oral
infection, smokers (exceeding 10 cigarettes/
day, or equivalent and patients chewing
tobacco), and patients with severe bruxism or
clenching habits. Participation in the study
was precluded in the presence of conditions
requiring chronic routine prophylactic use of
antibiotics or prolonged use of steroids, for
example history of rheumatic heart disease,
bacterial endocarditis, cardiac vascular
anomalies, prosthetic joint replacements, etc.
Patients with history of renal failure, bleed-
ing disorders, metabolic bone disorder,
uncontrolled endocrine disorders, HIV infec-
tion, alcohol or drug abuse, etc., with history
of leukocyte dysfunction and deficiencies and
history of neoplastic disease requiring the
use of radiation or chemotherapy (among
other criteria) were also excluded.
Local exclusion criteria comprised patients
with augmented bone, pathologic processes
at the implant site, untreated periodontitis,
mucosal diseases such as erosive lichen pla-
nus, history of local irradiation therapy, or
osseous lesions. Finally, patients were to be
excluded and treated in a different way if at
surgery, sufficient primary stability of at least
one implant had not been been achieved.
The implants were planned in healed sites
with adequate bone volume (tooth loss or
extraction >4 months prior to implant place-
ment and no need for bone augmentation).
The implant sites had to have adequate
native bone quality and quantity to place
implants with an endosseous diameter
≥4.0 mm. The opposing dentition had to
consist of natural teeth, a tooth or implant-
supported fixed restoration (no removable
prosthesis or complete dentures).
Standardized radiographs
To obtain constant projection geometries
between repeated radiographs, film holders
(XCP� Extension Cone Paralleling, Dentsply
Rinn, IL, USA) were modified for each
patient and implant site before implant place-
ment. An individual bite block and beam-
aiming device were produced and individual-
ized with pattern resin (GC Pattern Resin
LS�; GC Corporation, Tokyo, Japan) material
for each patient (Fig. 1). Indentations of the
bite block on the adjacent teeth secured the
repositioning of the film in the patient’s
mouth. The radiographs were taken with the
film placed parallel to the implants.
Table 1. Mean radiographic bone level measured at implant placement, time of loading and at3- and 6-month follow-up (i.e., the distance (in mm) measured from implant shoulder to first visi-ble bone-to-implant contact. The mean of the mesial and distal bone levels were used perimplant)
Implantation Loading 3 months 6 months
25% Quantile �0.81 0.13 0.85 0.83Minimum �1.78 �0.76 0.00 0.71Median �0.60 0.68 0.94 0.97Maximum 0.75 1.19 1.12 1.6175% Quantile 0.24 0.79 1.01 1.03
2 | Clin. Oral Impl. Res. 0, 2015 / 1–9 © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Hicklin et al �Early loading of hydrophilic implants
Clinical procedures
Two experienced and calibrated oral sur-
geons performed the implant insertion (SJ,
VC). All implants were placed according to
a standard single-stage procedure (nonsub-
merged) under local anesthesia. Two hours
prior to surgery, preoperative antibiotic pro-
phylaxis was provided with amoxicillin com-
bined with clavulanic acid (2 g Aziclav�;
Spirig HealthCare AG, Egerkingen, Switzer-
land). The inserted implants (SPI� ELE-
MENT RC INICELL�, Thommen Medical
AG) revealed a proprietary, microrough
(sandblasted and thermal acid etched),
hydrophilic endosseous surface (INICELL�;
Thommen Medical AG), and a 1-mm
machined collar. All implants were placed
following a standardized surgical protocol,
and the implant bed was prepared according
to the manufacturer’s instructions. The
hydrophilic surface was achieved by a chair-
side conditioning procedure following the
manufacturer’s instructions that included
wetting with a 0.05 M NaOH solution, pH
12.4 using the dedicated applicator
(APLIQUIQ�; Thommen Medical AG)
immediately prior to implant placement
(Fig. 2a and b). The completeness of the con-
ditioning process was verified visually as the
newly generated hydrophilic surface appears
dark gray (Fig. 2c and d).
The microrough implant surface border
was placed slightly below the bone crest
level (approximately 0.5–1.0 mm). After
implant placement, the implant stability was
assessed by ISQ measurement (Osstell�,
Gothenburg, Sweden). Prior to wound clo-
sure, the implant position was indexed using
a screw-retained impression coping that was
connected to the implant. The fit was
checked visually, and then, the impression
coping was bonded to the surgical stent
using a resin material (GC Pattern Resin
LS�; GC Corporation). Therefore, the dental
technician was able to connect the implant
analog to the surgical stent and transfer the
implant position to the planning model using
an altered cast technique. On this cast, the
dental technician fabricated the provisional
restoration (Fig. 3). As appropriate during the
study, bite blocks were positioned and stan-
dardized radiographs were taken after the
application of the healing abutment and the
wound closure.
The patients were then instructed to follow
standard postsurgical procedures for 2 weeks
(rinse with 0.12% chlorhexidine mouthwash
for 1 min, 3 x/day) (Buser & von Arx 2000).
In addition, they were advised to abstain
from hard food intake for several days.
Before insertion of the provisional recon-
struction at 21 days of healing, ISQ measure-
ments were repeated. If the ISQ values were
≥70 (mean of 3 measurements), the provi-
sional restorations made out of titanium
temporary abutments with acrylic veneering
were inserted. The screw-retained temporary
restorations were placed and torqued with 15
Ncm. All provisional restorations were made
with at least one occlusal contact to the
opposing dentition, which was tested with
the use of shimstock foil (Colt�ene/Whaledent,
Langenau, Germany).
The implants were restored only if the
following criteria were met:
• ISQ ≥70 (mean of 3 measurements)
• Absence of implant mobility
• Soft tissue conditions, which did not pre-
clude or made it unadvisable to proceed
with the placement of the provisional
restoration
• No complaints of pain or severe discom-
fort on palpation of the soft tissue and
implant during the removal of the healing
cap, or testing of mobility.
The day of implant loading was defined as
baseline (day 0). Patients were recalled for
follow-up 1, 3, and 6 months after loading.
At all three time points, ISQ values were
recorded. In addition, the following clinical
parameters were assessed during every fol-
low-up visit:
• modified plaque index (mPLI) according
to Mombelli (Mombelli et al. 1987)
• modified sulcus bleeding index (mSBI)
according to Mombelli (Mombelli et al.
1987)
• probing depth (PD)
• distance between the implant shoulder
and the mucosal margin (DIM)
• clinical attachment level (CAL = PD
+ DIM) according to Buser (Buser et al.
1990)
• the distance between implant shoulder
and the first visible bone-to-implant con-
tact (DIB) was measured at the mesial
and distal aspects of each implant after
implant placement (21 days before load-
ing), at loading (day 0), 3, and 6 months
after loading. One single examiner (S.H.)
evaluated all radiographs using the free
ImageJ software (ImageJ version 1.48u4,
National Institutes of Health, Bethsda,
(a) (b)
Fig. 1. Individualized bite block and beam-aiming device from: (a) Occlusal view; (b) Lateral view.
(a) (b)
(c) (d)
Fig. 2. Intra-operative conditioning: (a, b) Before and after activation; (c, d) Before and after wetting the implant sur-
face.
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd 3 | Clin. Oral Impl. Res. 0, 2015 / 1–9
Hicklin et al �Early loading of hydrophilic implants
MD, USA). All images were “scaled”
separately based on the known thread
height of 1.0 mm. The distance of the
implant shoulder to the first visible bone-
to-implant contact (DIB) was measured to
evaluate the crestal bone changes
mesially and distally of the implants.
Mesial and distal values were pooled prior
to statistical analyses.
Patient satisfaction was assessed using a
visual analog scale (VAS) at the 6 months
visit. Possible complications were recorded at
each visit.
Statistical analysis
MS Excel was used for data collection and
analysis. Data analysis included all recruited
patients. Results were reported using
descriptive statistics, and the changes of the
parameters over time were analyzed for sta-
tistical significance using the nonparametric
method by Brunner and Langer (SAS PROC
MIXED). Time, patient, and implant position
were treated as fixed effects (Brunner & Lan-
ger 1999).
Results
Patient recruitment for this observational
medical device performance study was
stopped before reaching the originally
planned 30 patients. Sixteen patients were
screened, and 15 patients (seven female, eight
male) were enrolled and received implants
within the study between April 2011 and
February 2013. One patient was a “screening
failure” as the presurgical cone beam com-
puted tomography showed insufficient bone
volume at the implant site (Fig. 4: patient
flow diagram). All patients were classified as
PS1 or PS2 with no recorded relevant medical
history or risk factors. A total of 11 of 15
patients received one implant, three patients
received two implants, and one patient
received three implants. The mean patient
age at the time of surgery (day -21) was 51
(range 32–67) years. Most (17, i.e., 85%) of
the implants were used to replace the first
mandibular molar, 2 (10%) the second, and 1
(5%) the first premolar. Eleven implants
(55%) had a platform diameter of 6.0 mm
(enossal length 8.0 mm), four implants (20%)
a platform diameter of 5.0 mm (L 8.0 mm),
and five implants (25%) a platform diameter
of 4.5 mm (L 8.0 and 9.5 mm). In summary,
all implants were placed in compliance with
the study protocol. The bone at the implant
site was rated as healed for all (20) implant
sites. The implants were inserted into healed
sites with good bone density and sufficient
bone volume. All study implants were
assessed by the surgeons as stable (tactile
assessment) with no complications reported
after implant placement. All implants were
(a) (b)
(c) (d)
(e) (f)
Fig. 3. Step-by-step fabrication of a provisional crown: (a) Surgical splint; (b) Pickup at day of surgery; (c) Fixation of
the analog; (d) Adaptation of the working cast; (e) Screw-retained provisional crown; (f) Insertion at day 21 with
occlusal contacts.
Fig. 4. Patient flow diagram.
4 | Clin. Oral Impl. Res. 0, 2015 / 1–9 © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Hicklin et al �Early loading of hydrophilic implants
loaded 21 (range 20–22) days after implant
surgery as at this time point all study
implants had an ISQ ≥70 (mean of 3 measure-
ments). Consequently, all implants were
restored with 18 temporary single crowns
and with one temporary fixed dental prosthe-
sis (FDP) as required by the study protocol.
ISQ values were recorded immediately
after implant placement (day -21), before
loading (day 0 = baseline (BL)) and also at
the subsequent visits up to 6 months after
loading (Fig. 5). The ISQ values showed a
trend toward a gradual increase from 78
directly after implant placement (range 56–
87, SD 7) to 80 (range 68–89, SD 5) at load-
ing (baseline (BL), 82 (range 74–88; SD 4), 84
(range 76–90, SD 4), and 85 (80–90, SD 3) at
1, 3, and 6 months postloading, respectively.
Compared to baseline (loading), the changes
in ISQ were statistically significant and
affected by the factors “time,” “patient,”
and “position” (all with P < 0.001) (Fig. 5a).
The ISQ values measured for individual
implants during the study period are also
shown (Fig. 5b). The changes in the ISQ val-
ues over time were also presented per
implant in Fig. 5b revealing that three dips
were seen between loading and 1 month and
2 between 1 and 3 months. Values below 70
were however not reached anymore.
Standardized radiographs were taken
immediately after implant placement, before
occlusal loading (baseline (BL)), 21 days after
placement, and 3 and 6 months after func-
tional loading. The results of the radiographic
evaluation of the changes in the bone levels
are shown in Table 1. Initial crestal bone loss
was observed during bone healing, that is, in
the 21 days between implant placement and
loading. Additional crestal bone loss was
noted during a 3-month remodeling phase.
Thereafter, minor changes of the crestal bone
levels (DIB) were observed until 6 months.
Compared to baseline (loading), the changes
in the crestal bone levels were statistically
significant and affected by the factors “pa-
tient” (P < 0.005) and “time” (P < 0.0001) but
not “position.” As expected, the most coro-
nal bone-to-implant contact stabilized on the
level of the first implant thread just at the
border of the moderately rough surface and
the machined collar (Fig. 6). In Fig. 7, serial
radiographs taken at surgical placement,
baseline, three, and 6 months later demon-
strate the slight remodeling observed in the
crest area.
The DIM and CAL results were shown as
boxplots (Figs 8 and 9, respectively). The data
reflected well-maintained stable clinical con-
ditions around the implants restored with the
provisional.
At the 6 months follow-up visit, the
patients were asked about their satisfaction
with the treatment outcome. All patients
were fully satisfied. The recorded mean VAS
was 9 (10 of 15 patients recorded a score of
10, 4 indicated 9, and 1 patient 8, with a
comment “I generally never give a 10”).
Discussion
This study was performed to test whether
implants with an intra-operatively condi-
tioned hydrophilic surface (SPI� ELEMENT
INICELL�; Thommen Medical AG) can be
safely restored with an early loading protocol
after 21 days in healed mandibular posterior
ridges of partially edentulous patients. At
6 months postloading, all 20 implants were
considered successfully integrated resulting
in a survival and success rate of 100%. The
study confirms the results of previous clini-
cal trials with hydrophilic titanium surfaces
and a 21-day loading protocol (Bornstein
et al. 2009).
Obviously, the new tested surface (SPI�
ELEMENT INICELL�; Thommen Medical
AG), similarly as the SLActive� surface
(Straumann), can clinically lead to
50
60
70
80
90
100
–21 days implantation
BL 1 month 3 months 6 months
ISQ
Visit
(a)
(b)
Fig. 5. (a) Boxplot of the ISQ values (1st measurement out of 3) from day of insertion to 6 months. FUP: follow-up.
Red bar: median, white box lower and upper limit: 25% and 75% quantile; error bars (black line -|): minimum and
maximum measured ISQ; black bar (-): refers to statistically significant difference (Brunner and Langer, SAS PROC
MIXED) P < 0.001 (patients, position, and visits), compared to results obtained at loading. (b) Individual ISQ values
(1st measurement out of 3) during the study period. Each line represents the ISQ course of a single implant.
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd 5 | Clin. Oral Impl. Res. 0, 2015 / 1–9
Hicklin et al �Early loading of hydrophilic implants
accelerated bone apposition during initial
healing. The bone response to a freshly
placed implant is dependent on many param-
eters. Factors that influence the quality and
the amount of primary stability include the
preparation of the implant bed, the density of
the peri-implant bone, the design of the
implant (i.e., thread configuration, length,
etc.), and the torque applied. With rough sur-
faces, a more intense bone-to-implant contact
(BIC) can be observed (Albrektsson &
Wennerberg 2004). The aim of additional
chemical modifications is to change the
hydrophilicity and thus the wettability of the
now differently charged surface. In addition,
the highly reactive titanium oxide surface
should be preserved until contact with blood
is made leading to a favorable conditioning
layer (Rupp et al. 2006). With the tested sur-
face (SPI� ELEMENT INICELL�; Thommen
Medical AG), the chemical modification
takes place during surgery by rupturing the
package membrane (APLIQUIQ�; Thommen
Medical AG) between the two chambers and
wetting the implant (Fig. 2). This can be
achieved in a simple procedure not requiring
a sophisticated industrialized process.
The amount of time spent between the
placement of an implant and the delivery of
the prosthetic reconstruction can be regarded
as one of the major patient centered out-
comes. In particular, if function and/or
esthetics are impaired, patients prefer a short
healing time. For some of the indications
such as the edentulous mandible and maxilla
even an immediate reconstruction after
implant placement may be considered
(Gallucci et al. 2009), whereas in the partially
edentulous mandible early loading protocols
can be advocated at least based on the exist-
ing evidence on this topic (Cordaro et al.
2009). The accelerated bone apposition in the
first 2 weeks after surgery may also reduce
the early failure rate of dental implants. In a
recent retrospective study, the cumulative
survival rate of 1337 implants with the modi-
fied hydrophilic surface (INICELL�) and 1581
with a sandblasted and thermal acid-etched
(TST�) surface (both Thommen Medical AG)
were reported. The reported overall failure
rate of the hydrophilic implants (0.5%) was
significantly lower than that of the hydropho-
bic implants (1.5%). All failures occurred
before implant loading (Gac & Grunder
2015).
Enhanced bone response may also be favor-
able for the osseointegration in low-density
bone (Hinkle et al. 2014). In 23 patients, 25
implants were placed after a delayed healing
of the extraction wound. Sites with a bone
quality of Class I and II were chosen, and the
implants were torqued to an average torque
of 40 Ncm (30–50 Ncm). One patient was
examined at 3 weeks revealing a noninte-
grated implant. The other implants received
a temporary crown at 3 weeks (range 2–
4 weeks). After 3 months, one temporary had
fractured, and therefore, a definitive crown
had been inserted. The implants had a 1 mm
high machined collar which was to be placed
supra-crestally at surgery. In fact, the radio-
graphic measurements of the distance from
the implant platform to the crest ranged from
0.92 mm to 1.10 mm at the day of delivery
of the provisional and at 6 and 15 weeks and
6 and 12 months after implant placement
(Hinkle et al. 2014).
To further test implants with the new sur-
face (SPI� ELEMENT INICELL�; Thommen
Medical AG), cases with class 3 and 4 bone
quality were chosen. In ten patients, 35
implants were left submerged for 4 weeks
and 8 weeks after second stage surgery these
implants were released for loading if a tactile
–2.00
–1.00
0.00
1.00
2.00
–21 days implantation
BL 3 months 6 months
mm
Visit
Bone level
Fig. 6. Boxplot of radiographic, pooled (mesial and distal) bone levels. Red bar: median, white box lower limit: 25%
quantile, white box upper limit: 75% quantile, error bars (black line -|): minimum and maximum measured values
(Brunner & Langer 1999); black bar (-): refers to statistically significant difference (Brunner and Langer, SAS PROC
MIXED) P < 0.01 (patients and visits) compared to results obtained at loading.
(a) (b)
(c) (d)
Fig. 7. Standardized serial radiographs obtained with a bite block and a beam-aiming device taken at the day of surgery
Fig. 7.a) at baseline (loading) (Fig. 7.b) and at three (Fig. 7.c) and six months (Fig. 7.d) with the provisional crown.
6 | Clin. Oral Impl. Res. 0, 2015 / 1–9 © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Hicklin et al �Early loading of hydrophilic implants
resistance of >35 Ncm had been achieved
(Held et al. 2013). From the 35 implants, one
was lost due to a soft tissue complication
and one due to failure related to a fractured
SmartPeg� (Osstell�, Gothenburg, Sweden).
The ISQ values started out with an average
value of 43 but demonstrated a steep increase
to 63 at 8 weeks and then up to 73 at
12 months. A torque ratchet (MONO torque
ratchet�; Thommen Medical AG) was also
applied to feel the resistance to untorque,
and the implants were released for prosthetic
reconstruction if the resistance was
>35 Ncm. In that study (Held et al. 2013),
the implant platform was placed at an equal
level as the crestal bone. Therefore, when
bone sounding with a periodontal probe was
applied at 12 months, a crestal bone loss of
about 1.5 mm was noted mesially and dis-
tally of the implants.
The outline of the present clinical study
resembles closely the protocol of an earlier
study, which tested if implants with a chem-
ically modified sandblasted and acid-etched
surface (SLActive�; Straumann) could be
safely loaded at 21 days (Bornstein et al.
2009). In 40 patients, 56 implants had been
placed and followed up to 26 weeks. The ISQ
values started out with a mean of 74.33 stea-
dily increasing to 83.82. Two implants were
diagnosed as spinners. One at day 21 when
one healing cap could not be removed and a
second one in another patient who reported
discomfort while the healing cap was turned
out. The parameter ISQ 38 at this time point
was very low. At week 7, the two implants
at risk showed an ISQ of 77 indicating an
increased osseointegration. At the end of the
study, all implants were healed in success-
fully.
At 2 and 3 years, examinations of chemi-
cally modified SLA implants stable clinical
and radiographic parameters were reported
(Bornstein et al. 2009; Morton et al. 2010).
The changes in ISQ observed during the
early healing phase were considered to repre-
sent a valuable tool to determine whether an
implant could be released for prosthetic
procedures such as impression taking and
loading with or without occlusal contact.
The only restriction is however the need to
remove the healing abutment for the installa-
tion of the measuring post which could
already disrupt the interface at an insuffi-
ciently integrated implant.
In contrast to previous preliminary studies,
the implants were not exposed to any
attempts to assess the resistance to detorque.
No negative events related to handling the
healing caps and the impression posts were
noted.
In the study by Bornstein et al. (2009) at
3 weeks, screw-retained provisional crowns
were delivered and torqued to 20 Ncm. If the
ISQ was below 65, no temporary was
inserted. Following this protocol, 57 implants
were loaded fine-tuned with a 20-lm
shimstock foil that could be hold while bit-
ing the teeth together. In case of a reduced
ISQ value 1 week later, the occlusal contact
would have to be reduced, but this second
adjustment was not needed during the study.
Fig. 8. Boxplots of the distance from the implant shoulder to the mucosal margin (DIM) measured at 1, 3, and
6 months after loading (pooled values of measurement at four sites around implant). Red bar: median, white box
lower limit: 25% quantile, white box upper limit: 75% quantile, error bars (black line -|): minimum and maximum
measured values.
Fig. 9. Boxplots of the clinical attachment level (CAL) measured at 1, 3, and 6 months after loading (pooled values
of measurement at four sites around implant). Red bar: median, white box lower limit: 25% quantile, white box
upper limit: 75% quantile, error bars (black line -|): minimum and maximum measured values.
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd 7 | Clin. Oral Impl. Res. 0, 2015 / 1–9
Hicklin et al �Early loading of hydrophilic implants
Since at day 21, all the implants demon-
strated an ISQ above ≥70 (mean of 3 measure-
ments) in the present study, the provisionals
were torqued to 15 Ncm and a contact to the
opposing dentition that could hold a shim-
stock foil was created.
The implants with a machined collar of
1 mm height were inserted with the recom-
mendation to place the line where the rough
surface started about 0.5–1.0 mm subcre-
stally. Thus, an initial slight remodeling of
the crestal bone was observed comparing the
radiograph taken at surgery with the one
taken at day 21. Following an additional
slight loss, the bone crest stabilized just
beneath the end of the machined surface.
This corresponds to the changes in the cre-
stal bone levels, which were reduced from
2.43 mm to 2.55 mm and 2.67 mm in rela-
tion to the platform of tissue level implants
with a different collar design (Bornstein et al.
2009). It has to be kept in mind that the
interface against a machined or minimally
rough surface may result in a somewhat
lower level where the crestal bone will stabi-
lize (Valderrama et al. 2011).
The clinical parameters obtained reflect
healthy, well-cleaned peri-implant conditions
without any negative impact inflicted by the
pickup method during surgery and the early
manipulation with the provisional. The pro-
cedure to prepare the temporary or even a
definitive crown based on an impression
taken at the day of surgery may also be
considered a time- and cost-saving approach
for posterior small reconstructions, which in
the future may be even changed to a com-
plete digital pathway for the fabrication of a
reconstruction (Joda & Bragger 2014).
The present prospective clinical case series
study has demonstrated favorable short-term
results for screw-shaped titanium implants
with a hydrophilic surface after 3 weeks of
healing using an early loading protocol. All
20 implants could be restored 3 weeks after
implant placement according to the study
protocol.
Thus, all implants in the present study
were considered successfully integrated at
the 6-month follow-up examination, result-
ing in a survival and success rate of 100%.
Reported here are the results of a prospec-
tive clinical case collection. Its goal, to docu-
ment the feasibility of early loading of
implants with a hydrophilic surface, was ful-
filled. According to the patients, responses to
the question related to their satisfaction only
high scores were noted.
Within the limitations of this prospective
clinical study conducted with 15 patients and
20 implants that were loaded 21 days after
placement, the clinical and radiographic out-
comes demonstrate that:
• Functional occlusal loading of implants
with a hydrophilic, moderately rough
endosseal surface 3 weeks after place-
ment in healed implant sites (without
need of GBR procedures) in the posterior
mandible appears to be a safe and
predictable treatment option.
• All placed implants osseointegrated, that
is, no implant was lost within the 6-
month follow-up period. No complica-
tions were reported within the observa-
tion period.
• The initial ISQ confirmed that all
implants had been placed into sites with
good bone quality and sufficient bone vol-
ume. The trend toward increased ISQ val-
ues 21 days after implant placement
confirmed that hydrophilic enossal sur-
face is well suited for use with early load-
ing protocols
• The radiographic crestal bone loss analy-
sis confirmed the marginal bone stabiliza-
tion just beneath the machined (1 mm)
implant collar.
A larger number of patients and longer fol-
low-up period are necessary to confirm these
results.
Acknowledgements: The authors are
not aware of any conflict of interest, that is,
they have no relevant financial relationship
with, they are not members of any board, and
they are not stockholders of Thommen
Medical AG. The company provided the trial
material free of charge, and the study
conducted by the School of Dental Medicine,
University of Bern, Switzerland, was partially
funded by Thommen Medical AG.
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Supporting Information
Additional Supporting Information may be
found in the online version of this article:
Appendix S1. CONSORT 2010 checklist of
information to include when reporting a ran-
domised trial
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd 9 | Clin. Oral Impl. Res. 0, 2015 / 1–9
Hicklin et al �Early loading of hydrophilic implants