A Randomized controlled Clinical trial which aim is to investigate the clinical outcome of<br /> dental implants in titanium-zirconium alloy compared to traditional titan-4 implants. The<br /> hypothesis is set to no difference in the clinical outcome for the two types of implants.<br /> Preliminary estimation of 96 patients needed. A pilot study will provide us with further data<br /> in order to more accurately specify the sample number."
Implants have been used for the purpose of replacing lost teeth since the 1960s. Since then,
the treatment of edentulism with dental implants has been implemented in a large scale. The
main reason for this is that research has shown that treatment with implants are very
predictable in terms of implant survival. The accumulated knowledge, as seen from 15 and 20
year follow-ups, has been based on prerequisites that are not always followed today. One of
them is that the implants used in the aforementioned studies are manufactured in titanium
that has good rigidity and is used as the main implant material today. In addition, the
studies have examined implants with a turned surface. This standard revised in the mid 1990s
when a series of studies showed increased and accelerated osseous ingrowth of implants with a
moderate raw surface that had been achieved by blasting. The related biological events
describing this process have been described in detail in the literature.
Today, other materials are being explored as an alternative to the well documented implant
material titanium with a focus on finding a material with higher stiffness combined with
equivalent biological characteristics. A stiffer material theoretically gives possibilities
for implants installations without bone augmentation in cases with reduced bone volumes.
An alternative implant material which has reached the clinic is titanium-zirconium alloy. It
has been shown to have an increased rigidity in comparison with titanium and comparable
biological characteristics but the documentation consists mainly of animal studies and short
term clinical follow-up in the form of case-series. Since it has been demonstrated that the
choice of implant material may influence osseointegration, it is necessary to evaluate the
implants made of titanium-zirconium in a clinical controlled study with long-term follow-up
in which the emphasis is put on the clinical outcome.
The aim of the study is to compare the clinical outcome of implants made of
titanium-zirconium with a proven implants made of titanium.
The scientific question in this project is if there are differences in the clinical outcomes
of an implant made of titanium and a corresponding implants in titanium-zirconium alloy.
Materials and Methods
Patients referred for implant treatment at the Department of Prosthodontics,
Specialisttandvården Borås will be asked to participate in the study and provide written
consent after review of delivered information sheet. Implants will be installed by two well
experienced surgeons at Oral Maxillofacial Surgery att Borås Regional Hospital according to
the protocol used for dental implant surgery and recommended by the manufacturer.
Two groups, matched for age and gender, will be defined after block randomisation for
smoking. The test group will receive titanium-zirconium implants and the control group
titanium implants. For a power of 80% and for p < 0.05, (SD = 1.66 according to previous
studies, estimates made from 1 mm difference in margin bone level between the groups), the
size of the groups has been defined as 44 patients per group. The investigators anticipate a
loss of approximately 10% and therefore, the investigators have increased each patient group
to 48 individuals. The data collection is completed when the number of patients has been
The evaluation will involve no additional clinical or radiological examinations as compared
to the usual procedures. Normally, this means examination and therapy planning, surgical
examination, implant installation, impression, placement of prosthetic restoration, baseline
X-ray, control/follow-up tightening of prosthetic screw/hygiene monitoring. No additional
time or costs arises in connection with participation in the study, the cost of both groups
National guidelines will be followed regarding possible need of antibiotic prophylaxis.
Registration will be done with regard to history of periodontal disease, smoking, medication,
and implant position in the jaw.
The data collection will take place at four different times: in connection with the placement
of the prosthetic construction (baseline) and after 1.3 and 5 years. Standard x-ray
examinations will be carried out to check the marginal bone level which will take place
through individualized x-ray holders that will be produced by impression material (Putty).
Registration of pocket depth, bleeding on probing, amount of keratinized mucosa and
measurements on x-ray will be done by the same person. Prosthetic complications and possible
total implant loss will be registered.
The marginal bone level for each implant will be presented as the average of the mesial and
distal bone level (primary outcome). The mean value of pocket depth will be recorded for each
implant at a 4-point measurement. The hypothesis is to be tested with the independent samples
The impact of restoration distance from the bone level, the effect of implant type, margin
bone level, bleeding on probing and pocket depth will be controlled using regression
analysis. SPSS is used for statistical analysis.
The hypothesis is that there are no differences in the clinical outcomes between the two
types of implants.
Potential benefits of the Project
The investigators can conclude that the materials are equivalent if there is no difference
between implant types available. Since, titanium-zirconium alloy has a higher stiffness than
titan, the investigators will be able to provide patients with thinner implant and thus
costly and painful treatments to optimize the width of the bone in the installation area
should be avoided.
From a social perspective, if it turns out that titan-zirconium have equal or better clinical
performance than titanium, can unnecessary healthcare costs for surgery for modulation of the
surgical site in the form of augmentation or sinus elevation associated with implant
treatment should be avoided. If optimizing surgery can be avoided, this means even shorter
therapy times and increased availability by the released health time which can be used to
more quickly treat other patients as possible had standing in line for their treatment.
Limits can be found in the study's applicability in general dentistry because all operations
are carried out at specialist clinic in which case the patient clientele and the processor's
level of expertise is not fully comparable with the general dentist.
Research ethical considerations
Treatment with dental implants in titanium is a known treatment that has helped to restore
good chewing function for many patients and years all over the world and can be thought of as
a safe treatment with high success rates. The study protocol calls for no difference in the
x-ray examination or the surgical protocol as compared to the procedures followed in regular
treatment basis. In previous studies, there is no listing of suspected allergy to
Patient information and storage of personal data in accordance with the recommendations of
the Board of ethical review.