A Retrospective Analysis of the ITI Implant System Used for Single ...

A RETROSPECTIVE STUDY OF THE ITI IMPLANT
SYSTEM USED FOR SINGLE-TOOTH REPLACEMENT
AT KING HUSSEIN MEDICAL CENTER:
PRELIMINARY RESULTS AFTER TWO YEAR LOADING
Sami Jebreen DDS, MSc Prosthodontics
ABSTRACT
Objective: The objective of this retrospective study was to evaluate the success rate of ITI implants used for
single tooth replacement after a minimum of two years of loading at King Hussein Medical Center.
Method: Dental records for 36 patients who underwent single tooth replacement using ITI implant system at
King Hussein Medical Center during a four year period (2000-2004) were retrospectively analyzed. Only
implants that were functioning for at least two years were included.
Results: Forty-nine ITI implants were used for the replacement of single teeth in 36 patients, 31 (63,26%)
implants were placed in the posterior regions, and 18 (36.74%) implants were placed in the anterior regions.
All implants were restored with cement-retained crowns and have been in function for at least two years. Out
of the total 49 implants, three (6.2%) were considered failures as a result of significant radiographic bone loss.
Therefore, the survival rate at two years was 93.8%.
Conclusion: The results of this study suggested that ITI implants could be a satisfactory choice for
posterior single tooth restorations.
Key word: ITI-Implant, Single tooth replacement, Success rate, International team of oral implantology
(ITI).
JRMS February 2010, 17(Supp 1): 16-19
Introduction
The successful application of osseointegrated
implants is well documented in completely
edentulous, (1) partially edentulous, (2,3) and singletooth
application. (4-6) Indications for single tooth
replacement by implants include trauma, congenital
missing teeth, presence of healthy teeth adjacent to
single tooth gap, and intact prosthetic reconstruction
of neighboring teeth. This treatment modality also
provides an ideal fixed replacement in spaced
dentitions.
The objective of the present study was to evaluate
the success rate of ITI implants used for single-tooth
replacement after a minimum of two years of
*From the Department of Dentistry, King Hussein Medical Center, (KHMC), Amman-Jordan.
Correspondence should be addressed to Dr. S. Jebreen, (KHMC), E-mail: samijeb@hotmail.com
Manuscript received November 24, 2004. Accepted March 24, 2005
loading at King Hussein Medical Center.
Methods
All patients planned for replacement of missing
teeth by dental implants were assessed clinically by
a prosthodontist and the periodontist carefully
before initiating their treatment. Patients were
selected on the basis of the following inclusion
criteria:
− The presence of one or two missing teeth per
edentulous space.
− Adjacent teeth structurally sound and
esthetically acceptable to the patient.
− Maladaptive experience or refusal to wear a
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emovable partial prosthesis or conventional
bridges.
− Adequate interarch space for abutments,
prosthetic components, and prosthesis.
− The vital anatomic structures are far away to the
proposed implant site.
Exclusion Criteria:
− All patients with chronic diseases like
uncontrolled diabetes or psychiatric illness.
− Unrealistic patient expectations of the treatment
with respect to esthetic comfort and function.
− Insufficient bone dimension for implants.
Patients were seeking treatment to restore the
missing teeth created by tooth loss resulting from
caries, periodontics, endodontics complications,
trauma, and congenital deficiency. The edentulous
areas that were to receive the implants, as well as
the adjacent structures, were evaluated using an
appropriately prescribed combination of periapical,
occlusal, panoramic radiographs.
Dental records for 36 patients who underwent
single tooth replacement using ITI implant system at
King Hussein Medical Center (KHMC) during a
four year period (2000-2004) were retrospectively
analyzed. Only implants which were functioning
for at least two years were included. For the
objective of this study, the success rate was recorded
according to the criteria suggested by Albredtsson et
al (7) as follows: The unattached implant is immobile
when tested clinically, no evidence of peri-implant
radiolucency appeared radiographically, vertical
bone loss is less than 0.2mm annually after the
implants’ first year of service, absence of persistent
and/or irreversible signs and symptoms such as pain,
infection, neuropathies, paresthesia, or violation of
the mandibular canal.
The patients were recalled one week, four weeks,
and eight weeks following screw implant insertion
in the bone. The second stage started after eight
weeks in order to fabricate the final prosthesis. After
placement of final crowns, all patients were
reviewed at two weeks, three weeks, and six
months. The condition of the prosthesis, implant
stability and adjacent mucosa were all evaluated at
each recall appointment, patient symptoms were
also recorded and used along with the clinical and
radiographic signs to diagnose the implant status.
Results
Out of the total 36 patients, there were 20 females
and 16 males. Their age range was 18-65 years
(mean 41 years), and 14 patients were smokers.
Forty-nine single tooth implants were placed, 31
implants were placed in the posterior region, and 18
were placed in the anterior region. Nineteen
implants were placed in the mandible and 30
implants were placed in the maxilla (Fig. 1&2).
Data regarding the number of implants and duration
of placement are presented in Table I.
All implants were restored with a cemented
restoration using the solid conical abutment. The
predominant type of implants placed was the solid
screw. Regarding the length and diameter of the
implants, 35 implants were 4.1 mm in diameter and
10mm in length, 9 implants were wide neck with
8mm length, the remaining 5 implants were narrow
neck implants and 10mm in length (Table II).
Three implants were considered as failures till the
time of this report. One implant was lost while two
implants exhibited significant bone loss.
Radiographic failure was noted in one of the
mandibular sites (right first premolar) and one of the
maxillary sites (left second premolar), and one of
the implants (second right maxillary molar) was lost
during abutment connection due to poor quality of
bone at this site.
Following crown placement, two patients had soft
tissue complication with mucosal tissue surrounding
the abutment and one patient had prosthetic
complication with fracture of porcelain layer.
Discussion
Retrospective and prospective studies on single
tooth replacement by implants are the most
important source of information about this treatment
modality. Results of these reports demonstrate a
favorable survival rate and patient satisfaction when
the ITI single-stage system was used to replace
missing teeth. (3-5)
The results of this study revealed that the shortterm
survival rate of the 49 implants loaded for a
minimum of two years was 93.8%. Three implants
(6.2%) were considered failures; the reason for the
first implant failure could be related to the quality of
the bone since this implant was placed in the upper
second molar region. Although initially the peri-
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Table I. Number of implants and the date of placement
Date of implant placement No. of patients No. of implants
2000 6 9
2001 7 13
2002 12 16
2003 11 11
Total 36 49
Table II. Implant distribution by length and diameters and the area of placement.
Diameter Length/mm No. of implants % Area of placement
3.3 10 5 10.2 Anterior area
4.1 10 35 71.4 Premolars and missing upper centrals.
4.8 8 9 18.3
Posterior area to replace missing upper and
lower molars.
No. of Implants
12
11
10
9
8
7
6
5
4
3
2
1
0
Central Lateral Canin 1st Premolar 2nd Premolar Molar
Tooth Number
Mandible
Fig. 1. The locations of the 19 mandibular implants (12 in the molar region)
No. of Implants
11
10
9
8
7
6
5
4
3
2
1
0
Central Lateral Canin 1st Premolar 2nd Premolar Molar
Maxilla
Tooth Number
Fig. 2. The locations of the 30 maxillary implants (5 in the molar region)
apical radiograph showed integration around all the
implant surfaces, when abutment connection was
done using torque device to tighten it in a 32 Ncm,
the solid screw implant rotated with the device
which necessitated its removal three days later. For
the other two implants, there was a bone defect at
the site of implant noted during implant surgery.
This was treated by curettage to remove all fibrous
tissues and bone substitute materials (Bio-Oss) were
used to fill the defect.
These two implants, are still functioning, but were
considered as failures. The incidence of soft tissue
complications was low.
The most obvious difference between the present
report and a study by Jemt et al. (4) is the location of
the implant placement. In their study, no maxillary
molars were included, and only five mandibular
molars at one year (4) with three mandibular molars at
three years (8) examination were included.
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The present study revealed successful treatment
with short implant (10mm or less) since they
represent all of the implants. Balshi (9) has suggested
avoiding short implants (13mm and shorter)
posteriorly and recommended the placement of two
implants whenever possible for single-molar
replacement to better withstand heavy occlusal
loading seen in molar areas.
Rangert and Sullivan (10) have also reported the
fracture of a 3.75mm wide implant resulting from
bending movement when one implant is used to
replace a single molar. Based on the short-term data
of this study using titanium single stage ITI
implants, initial findings do not support this
suggestion, considering that 34.6% of all implants
were placed in molar regions with minimal
restoration problems and no complications or
implant fracture.
These short-term data suggest that the application
of single-stage ITI implants can be a valid choice for
posterior single tooth replacement as well as for
anterior single tooth replacement.
Regarding the success rate of ITI implants used
for the replacement of single tooth, it can be noted
that there was no difference between the results of
this investigation and previous reports.
Conclusion
The use of ITI implant system to support fixed
crowns appears to be a highly successful treatment
alternative for restoration of the partially edentulous
patient. Satisfactory treatment outcomes are
possible for a broad range of patient as documented
in this study.
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