3. Author
• Correspondence to: Dr Torsten Mundt,
University of Greifswald,Department of
Prosthodontics, Gerodontology and Dental
• Materials, Rotgerberstrasse 8, D-17475
Greifswald, Germany.
4. Purpose:
• To evaluate changes in marginal bone levels
around maxillary and mandibular mini-
implants stabilizing complete dentures and to
explore possible risk factors associated with
bone loss.
5. Exclusion criteria
• radiographic evaluation were
(1) patient refusal of follow-up radiography
(2) measurements not possible because of poor image quality of
the postoperative and/or follow-up radiograph.
6. Inclusion crteria
• Patients’ medical records were evaluated and the
presence or absence of any chronic disease was
noted.
• smoking habits were recorded using a questionnaire
such that patients were classified into
• nonsmokers,
• former smokers, and
• current smokers
7. Implant selection
• The 10- to 18-mm-long mini-implants had diameters of 1.8,
2.1, and 2.4 mm flap,
• 1.1-mm-diameter spiral drill was used to initiate a pilot hole
through the superior cortical plate and drilled to about one-
third to one-half of the screw length. The self-tapping
implants were inserted using different finger drivers, followed
by a ratchet.
8.
9. • Implants with an insertion torque > 35 Ncm
were loaded immediately.
• If the insertion torque of one implant was < 35
Ncm, the denture was rebased with a soft
liner (Secure Soft Reline Kit, 3M ESPE)that
embraced the O-ball heads.
10. Assesment
• Digital radiographic files were imported into radiographic image analysis
software (Byzz version5.7.2, Orangedental).
• The digital images were surveyed using the digital caliper within the
software.
• Conventional panoramic x-ray films were not scanned but directly
surveyed on a dental negatoscope (Dentsply Rinn, Dentsply DeTrey) using
×3.5 magnifying spectacles and a ruler.
• The distance from the attachment base to the first visible bone-to-implant
contact was measured twice at the mesial and distal sites of the implant
by two experienced dentists, and the values were averaged
12. Data Analysis
• The data for this retrospective and follow-up study were collected from
nine private dental practices between August 2010 and February 2012.
• Patients who received mini dental implants (MDI, 3M ESPE) in edetulous
maxillae and/or mandibles between 2006 and 2010 to stabilize complete
dentures were evaluated.
Out Of the 133 participants (79 women and 54 men, response rate:
73.9%) 38 received implants in the edentulous maxilla, 79 received
implants in the mandible, and 16 received implants in both arches.
Out Of the 336 implants placed in 54 maxillas and 402 implants placed in
95 mandibles, 15 maxillary implants and 11 mandibular implants were lost
after insertion,and 4 mandibular implants fractured during or after
insertion
13. Result
Maxillary mini dental implants showed a trend toward more
bone loss than mandibular mini dental implants
A previous smoking habit, but not a current smoking habit,
was a possible risk factor for bone loss. Furthermore, implants
with a low insertion torque, which were loaded initially by
soft relined prostheses and loaded 3 to 4 months later by the
implant housings, showed more bone loss than immediately
loaded implants, which had been placed with a high insertion
torque..
14.
15. Disscusion
• The bone loss around mini-implants that were
used to stabilize complete dentures was
higher in the maxilla than in the mandible.
• The average bone loss over the mean
observation period of 2.3 years was
remarkably below the limit of 1.5 mm in both
arches.
16. • Some limitations in this study merit
consideration.
• First, more than one-fourth of the invited
patients were lost to follow-up, and an
additional 11 study participants were excluded
because of a lack of radiographic
data.
17. A second limitation may be the use of panoramic radiographs
that were taken with different conventional and digital x-ray
units in the nine dental practices.
Although periapical radiographs have been suggested to be the
gold standard for measuring marginal bone loss at teeth and
implants.
The magnification error issue can be eliminated by knowledge of
the actual implant length and number of screw threads.
18. conclusion
Mean marginal bone loss around mini-implants used to stabilize complete
dentures was insignificantly higher in the maxilla than in the mandible
after a mean observation period of 2.3 years.
These values are comparable with marginal bone loss around standard-
diameter implants.
A previous smoking habit and delayed loading after implant placement
with a low insertion torque were shown to be possible risk factors for
bone loss