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INTRODUCTIONWhat is a dental attachment
METHOD OF STUDY
RESULT
ABSTRACT
International standard, ISO for dental
attachment
Before Amendment After Amendment
ISO 13017:2015 ISO 13017:2020
Performance Test Methods of Dental Materials(Magnetic Attachment, Dental Ceramic) Reflecting Latest International Standards
Ji-Min Yu, Seen-Young Kang, Jun-Seok Lee, Jae-Won Lee, Ho-Sang Jung, Seung-Youl Lee*Medical Device Research Division, NIFDS, Ministry of Food And Drug Safety, Osong, Korea
E-mail : [email protected]
comparison of international standard (ISO 13356) revisionsrelated to dental attachments
Definition
Device used to secure the crown of a restoration or to accurately stabilize removable dentures. There
are fixators in the crown and fixators outside the crown.There are various types of dental attachments,
such as stud type, bar type, and magnetic type. Among these, magnetic attachments are actively used
for advantages such as reducing lateral pressure applied to an implant by using the force of magnetic
force, convenient attachment and detachment of dentures, and excellent vertical holding power.
International standard, ISO for zirconia
ceramic
Before Amendment After Amendment
ISO 6872:2008 ISO 6872:2015
Examples Application
What is a dental ceramic
Definition
It is a ceramic material used to manufacture dental restorations such as inlays, artificial teeth, crowns,
bridges, etc. It is a ceramic material that is processed by a dental computer-assisted design and
manufacturing unit. Dental ceramic, which is a material for tooth-shaped prostheses used in removable
dentures, is very promising due to its mechanical strength comparable to metals and excellent esthetics.
Examples Application
The bonding surfaces of the magnet (or magnetic
assembly) and the keeper or other magnet are
bonded to the top and bottom of the ball bearing
slider using cyanoacrylate adhesive. A low-friction
ball bearing slider that can hold the specimen and
pull it vertically is mounted on a mechanical
property tester. The load is applied at a crosshead
speed of 2.0 mm/min or less until the magnet (or
magnetic assembly) is completely separated from
the keeper or other magnet. Tensile force
measurement is carried out until the measured force
value remains constant within the range of ± 0.01 N,
then the machine is stopped. The holding power test
for the same set is repeated 5 times.
Retentive force method of ISO 13017:2020
3-point flexural strength method of ISO 6872:2015 Specimen dimensions used for flexural strength: Width (4 ± 0,2) mm
(dimension of the side at right angles to the direction of the applied
load), Thickness: (2,1 ± 1,1) mm (with 3,0 mm recommended;
dimension of the side parallel to the direction of the applied load),
Chamfer c = (0,12 ± 0,03) mm [with a maximum of 0,10 mm
recommended for small thickness specimens (b < 2,0 mm)] Universal
mechanical testing machine: capable of a crosshead speed of (1 ± 0,5)
mm/min and an ability to measure applied loads of between 10 N and
[1 000 N or 2 500 N] Fixture for three-point bending: consisting of
support rollers(1,5mm to 5mm ± 0,2mm, in diameter) positioned with
their centres 12,0 mm to 40,0 mm (± 0,5 mm) apart. The load shall be
applied at the midpoint between the supports by means of a third roller
(1,5 mm to 5 mm ± 0,2 mm, in diameter). Method: Measure the cross-
sectional dimensions of each test piece to ±0,01mm. Then, place a test
piece centrally. on the bearers of the test
Flexural strength result of zirconia material dental ceramic
Flexure stress at Maximum Flexure
load (MPa)
3hr 57min 6hr 28min 10hr 51min
1 810.16 791.80 826.03
2 731.34 984.72 823.49
3 734.18 605.70 915.01
4 651.90 725.89 668.46
5 796.32 783.77 726.11
6 932.04 644.53 787.34
7 802.82 1010.28 782.72
8 812.05 867.65 843.02
9 860.53 865.68 667.42
10 823.43 853.99 734.83
11 695.40 837.48 677.47
12 805.54 938.61 682.63
13 734.12 634.54 761.27
14 740.34 666.30 906.53
15 638.25 733.46 639.42
Maximum 932.04 1010.28 915.01
Median 796.32 791.80 761.27
Minimum 638.25 605.70 639.42
Standard
Deviation78.15 127.61 87.83
Mean 771.23 796.29 762.78
Recommended clinical indicationsFlexural strength minimum value
[MPa]
1a) Monolithic ceramic for single-unit anterior prostheses, veneers, inlays, or onlaysadhesively cemented.
b) Ceramic for coverage of a metal framework or a ceramic substructure.
50
50
2
a) Monolithic ceramic for single-unit anterior or posterior prostheses adhesively cemented.
b) Partially or fully covered substructure ceramic for single-unit anterior or posterior prostheses adhesively
cemented.
100
100
3
a) Monolithic ceramic for single-unit anterior or posterior prostheses and for three-unit prostheses not involving
molar restoration adhesively or non-adhesively cemented.
b) Partially or fully covered substructure for sin-gle-unit anterior or posterior prostheses and for three-unit prostheses
not involving molar restoration adhesively or non-adhesively cemented.
300
300
4a) Monolithic ceramic for three-unit prostheses involving molar restoration.
b) Partially or fully covered substructure for three-unit prostheses involving molar restoration.
500
500
5Monolithic ceramic for prostheses involving partially or fully covered substructure for four or more units or fully
covered substructure for prostheses involving four or more units.800
The experimental results were 771 MPa in (1group: 3hr 57min), 796 MPa in
(2group: 6hr 28min), and 753 MPa in (3group: 10hr 51min). All three groups
showed similar strength, but it was the best at 6hr 28min, and the mechanical
strength of zirconia ceramic was found to be affected by the firing time.
Figure I. Schematic diagrams of closed magnetic circuit
attachment: left) sandwich type, right) cup-yoke type Figure2.Typeofattachment
Balltype Magnetictype BartypeTelescopictype
Figure 3.. Zirconia ceramic blocks Figure4.Examplesofrestorationsfordentalprostheses
Figure 5. Device using a low friction ball bearing slider for fixing and pulling the specimens vertically
Figure 6. Flexural strength test machine
Figure 7. Production process of specimen using CAD(computer aided design)/CAM( computer aided manufacturing)
machine so that the load is applied to a 4mm wide face along a line perpendicular to the long axis of the test piece
and determine to ±0,1 N the load required to break the test piece. Use a cross head speed of (1 ± 0,5) mm/min.
Repeat the procedure with the remaining test pieces.
contents ISO13017:2012(Amd2015) ISO 13017:2020 revision
6.3 Retentive force
6.3.2 Test procedure
Load the test specimen in tension in the mechanical
testing machine at a cross-head speed of 5.0 mm
min−1 or less until the magnet or the magnetic
assembly separates completely from the keeper.
Load the test specimen in tension in the mechanical
testing machine at a cross-head speed of 2.0 mm/min or
less until the magnet or magnetic assembly separates
completely fromthekeeperortheothermagnet.
Cross-head
speed 5 → 2
6.3.3 Fixing procedure
6.3.3.1 Fixation of
specimens
Adjust the position of the lower-table equipped with the
device using the X-Y stage so that both centers of the
lower and upper-table are aligned. Attach the mating
face of the magnet (or magnetic assembly) to the centre
of the lower-table using an adhesive double sided tape.
Note that the side attached to the double sided tape will
be theside thatmateswiththeothermagnet (orkeeper)
oncethealignmentprocedure iscompleted.
Adjust the position of the lower non-magnetic table
equipped with the device using the X-Y stage so that
both centers of the lower and upper non-magnetic table
are aligned. Provisionally place the mating face of the
magnet (ormagneticassembly) to thecentreof the lower
non-magnetic table.Note that theside incontactwiththe
lowernon-magnetic tablewillbe theside thatmateswith
the other magnet (or keeper) once this alignment
procedure iscompleted.
Adhesive double
sided tape delete
Retention force
graph change
6.3.5 Analysis -
Convert the time values on X axis into distance
according to the Formula (1). Speed is a constant value
since the same crosshead speed is maintained
throughout theexperiment.
d=v× t (1)
where
disthedistance, inmm;
visthespeed, inmm/min
t is thetime, inmin.
Retention force
analysis
description
added
CONCLUSION
REFERENCE
ACKNOWLEDGMENTThe research was supported by a grant (18171MFDS301, 20171MFDS346) from Ministry of Food and
Drug Safety in 2018, 2020.
The results of this study contribute to the vitalization of the Korean dental medical device industry and
keep pace with the latest research trends by conducting research on the mechanical properties of
removable dentures and dental prostheses by applying the newly revised international standard test
method.
[1] 13017:2020Dentistry—Magnetic attachments.
[2] ISO6872:2015Dentistry—Ceramic materials .
[3] M.A. Tara, S. Eschbach, S. Wolfart, M. Kern, Zirconia ceramic inlay-retained fixed dental prostheses – first clinical results with a new
design.
공익신고자 보호제도란?
-공익신고자등(친족 또는 동거인 포함)이 공익신고 등으로 인하여 피해를 받지 않도록 비밀보장, 불이익보호조치, 신변보호조치 등을 통하여 보호
하는 제도
♣보호조치 요구 방법
전화02-360-3761/우편(120-705)서울시서대문구통일로81국민권익위원회공익보호지원과/팩스02-360-3567
The purpose of this study is to evaluate the mechanical properties of a dental prosthesis used with restoring a removable denture when there is partial loss of teeth, and also to guide the revision status and
up-to-date of the international standards applied in the mechanical property evaluation. When a lost tooth is restored with a removable denture, a medical device called a dental attachment is used to help
the removable denture be positioned in a stable state without being separated from the gum. This study is to evaluate Magnetic attachment with excellent retention and easy attachment and detachment of
dentures, and Zirconia ceramic used as artificial teeth for removable denture. The standard related to dental attachments are ISO 13017 Dentistry — Magnetic attachments, and the standards for dental
ceramics made of zirconia are ISO 6872 Dentistry — Ceramic materials and ISO 13356 Implants for surgery — Ceramic materials based on yttria-stabilized tetragonal zirconia (Y-TZP). The ISO 13017
standard was revised in 2020, and ISO 6872 and ISO13356 were revised in 2015, respectively.
Table 1. Comparative analysis of the revisions of international standard 13017
Table 1. Classification of ceramics for fixed prostheses by intended clinical use with required
mechanical properties
Table 3. 3-point bending strength test result
The K
orean
Mag
netics
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ty