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| Research and Development |
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| Test Protocol TP# 001 |
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| A comparative study between three Generic Implants |
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- SCOPE
The scope of the present protocol is to compare:
- The state-of-the-art manufacture of contact areas between
implants and prosthetic abutments, in order to determine the
horizontal and vertical gap of the components of each one
of the implant systems studied.
- The reverse torque needed to unscrew the fastening screws
of the abutments.
- Work hypothesis focuses on the difference of the tapping
of the internal thread of the implants, which would have an
influence on their quality standard.
- FUNDAMENTALS / PRECEDENTS
- OsseoMate II implants are internally threaded by the Single
Point system. With this system, the thread is made using a
tool formed by a shank and a hard-metal insert with the profile
of the thread, digitally controlled by a screw-swiss CNC turning
machine. This process is carried out in the same machine that
manufactures the piece, with no need of a second operation.
This process guarantees a perfect alignment of the internal
thread with the implant axis. The Single Point system cuts
the threads in the internal hole creating the thread M2 x
0.4 and thus guaranteeing a tolerance of 6H.
- Lot 1 & Lot 2 implant samples are internally threaded
by a different method.
- REFERENCES
- QAP#002. Discovery, Audit, Clearance and Suppliers Control
System.
- Production Order S#058. Threaded-Implant Assembly.
- Metric Threads (tolerance of M2 x 0.4 – 6H), IRAM
5053 or DIM 13 Standards.
- QAP#040: Calibration Program.
- QAP#068: Calibration Standards.
- DOCUMENTATION
Prepare a final report and include, discuss, or make reference
to, the following (according to what is required):
- Any deviation from this protocol or abnormalities that
might take place during the comparative study.
- Copies of calibration records of all instruments associated
with the comparative-study process.
- Copies of partial records that concern the completion of
this protocol, be them from QA/QC or of external contractors.
- PROCEDURE
- Obtain 5 random samples of each implant brand name.
- Lot 1 Implants
- Lot 2 Implants
- OsseoMate II Implants
- Take each implant out of its original container and inspect
visually the pieces, verifying their condition.
- Write down Lot number and origin in Appendix I. Work with
one Implant Lot at a time, performing the correspondent production
line set-up.
- Take a random sample of each Implant Lot, put the implants
inside a sealed plastic bag and label them with their origin,
part number, Lot number, and the legend “INTI”.
It will be sent to INTI, where they will carry out a study
on sweep electronic microscopy in order to see the contact
areas between implants and prosthetic abutments, with the
aim of establishing the horizontal and vertical gap of the
components of each implant system studied. Put the other 4
Lot Implants in a sealed plastic bag and label them with their
origin, part number, Lot number, and the legend “ENGINEERING”
in order to subject them to dimensional cheking: 1) tolerance
of the internal thread of M2 x 0.4 – 6H, 2) major diameter
of the implant head, 3) tolerance of the fastening screws,
and 4) measure the unscrewing torque as it follows:
- Fix the implant to the “torque fixture” and
then fit the torque fixture to an adequate torque sensor.
- Begin by mounting a fastening screw from each Lot on the
0.048 Hex Driver Tool and place it vertically on the internal
thread of the implant.
- Make yourself sure that abutments are properly positioned
and screw the fastening screw onto the bottom of the implant,
manually but without tightening.
- Place a torque wrench calibrated to 30 Ncm on the 0.048
Hex Driver Tool so as to have the arrow directed clockwise
when seen from above. Turn the torque wrench clockwise until
the shank of the torque wrench “breaks”. This
will provide an adjustment force calibrated exactly to 30
Ncm.
- DO NOT OVERTIGHTEN THE SCREWS.
- Then comes the disassembly, connected to the Norbar torque
sensor so as to obtain the counter-clockwise torque applied
through the record of the maximum value of the unit. These
operations will be repeated 5 (five) times for the same implant,
registering values (I,II,III,IV y V) in the Appendix. The
accuracy in the measurement of the torque is ± 1%,
and final measurement uncertainty will depend on the repeatability
of the results.
- The operations 5.7.1 to 5.7.5 will be repeated for all other
implants registering force values for each case.
- Continue in the same way with the other 2 Implant Lots registering
the following specifications:
- Torque for the 3 Implant Lots (4 implants/lot and 5 measurements
per implant).
- Tolerance checking of M2 x 0.4 – 6H of the implant
internal thread (verifying with go/no go gage).
- Dimensional checking of the fastening screws for each Lot
(mean diameter and major diameter).
- With Appendix I results, calculate averages and deviations
(statistics) for each test group.
- Write a report analyzing the information comparatively and
express there all possible conclusions.
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