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Gaps at the interface arch wire-chamfered slot allow old,
loose creeping there impairing sliding
The sharper the angle of the elastomeric ligature
over the arch wire, the higher the friction
Buccal and section views of two SLBs, In-Ovation R and
Damon 3MX. Their empty spaces renders them resilient.
2. Can you trust Ortho-Cycle and its “Insiders” ? Others did...
3. ORTHO-ARMAMENTARIAN, OR JUST A VAIN OCTOGENARIAN?
Claude Matasa’s Insiders: exercises in futility or substantial contributions?
4. Colleagues’ biased voice
1. Today’s one-piece brackets provide higher bond strengths than the foil-mesh-based ones
Base surface measurement. Brackets on millimetric paper before and after spraying with ink. 1. Ormco’s Mini Diamond; 2. Dentaurum’s Discovery; 3. Forestadent’s Sprint; 4. Pyramid Orthodontics’ Prestige; 5. Unitek’s Miniaturized Twin; 6. ORJ Orthodontics’ VST
2. Flexible brackets and bases are a guarantee against enamel failure
The same mesh retains less adhesive (lower bond strength) when its lamination to the foil takes place under too high pressure
The ace in the hole: some brackets
and bases are flexible, others are not
3. Nylon O (polycaprolactone), and orthodontics
Break routine: it will make it easier
for you and your lab...
Dr. Matasa at AAO convention demonstrating
polycaprolactone’s properties
Attachments that can be made from Nylon O
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Bond strength tester. 1. Fastened copolymer plate having tubes bonded to bovine teeth, tensile test; 2. Laminated mesh plate with bonded tubes bonded for shear tests; 3. Force gauge; 4. Paded support with pulleys & wire; 5.Winch
Tubes tested, mesh bases (manufacturers).
1. Unitek; 2. American Orthod.; 3. Lancer; 4. Ormco (Ti);
5. American Orthod.; 6. Speed, Strite Ind.; 7. Dentaurum;
8. Rocky Mountain; 9. Ormco 3MX, self-ligating;
10, 11. Rocky Mountain; 12. Ormco (A+); 13. Ormco;
14. Rocky Mountain; 15, 16. Unitek; 17. Speed,
Strite Ind.; 18. American Orthodontics; 19. Ormco;
20. Idem (Ti); 21. Unitek; 22. Ormco (A+);
23, 24. American Orthodontics;25. GAC
Why some tubes do not bond as expected
Just “presumptions”?
Tubes exhibiting the same mesh, but differing in depth.
To compensate, the manufacturer has etched the first’s base.
Structure of some multi-layered tubes. The red arrow
represents the deformation. Maximum stress bearing
areas are marked with grey.
1. Self-ligating brackets and friction
Arrangement of a dynamometer (tubular scale) and the
of the archwires used. 1. Weight to immobilize the scale;
2. Scale; 3. Parts of arch wires; 4. Sliding attachment
Arrangement allowing the recording the force
opposed to the ligated bracket
2. Bond Strength’s “Mass Testing” of Orthodontic Attachments
Bond strength tester with a “teeth holder” which
self adjusts to tensile by the force exerted.
3. Manufacturers encourage recycling !
In-Ovation R bracket exhibiting holes
Unitek’s Damon 3MX brackets exhibiting
dentification marks in slot
1. “Orthodontic biomaterials. Properties and Problems”
2. Complications of the Tongue Cancer Treatment – A Case Report
C G Matasa’s PET Scans, September 2006, and
September 2009. The white spots reveal tumors
3. Self-ligating brackets’ malfunction:
is it due to corrosion ?
Forestadent’s Mobil Lock bracket (1979). Section, brass and then stainless steel “variable slot”
In-Ovation bracket™. a. Before corrosion;
b. Open to show source of blockage; c. Detail
Effect of a. electroless copper plating (test for passivation)
and b. of corrosion on the same self-ligating bracket
4. Where are the Edward Angles and Rafael Bowens of today?
1. Self-ligating brackets, a gain for
almost everybody
GAC/Dentsply’s In-Ovation R ™bracket: view of the clip
and its closeness to the base. The latter is so thin
that the brackets’ welding lines are apparent.
Ormco’s Damon 3MX™ bracket: view of the sliding door and
of a hole above the base destined to receive a power arm
Group of In-Ovation R™ brackets seen as debonded.
Observe unscathed bases and mesio- distal
whitish borders of the cured adhesive.
Bases of Demon 3MX™ brackets seen after adhesive
removal. The first, a, like most of the others, was very
likely de-bonded by mesio-distal attack,
in contrast with the other, b.
2. Self-ligating brackets’ malfunction:
is it due to corrosion ? II
Self ligating brackets, with and without their
sliding door/clip, showing corrosion
View and section of the self-ligating brackets subjected to accelerated corrosion. The areas prone to malfunction
are shown lightly colored
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