Orthodontic Brackets - Science topic

Dear...

If the adhesive type is not of prime importance during the course of the study (not necessarily an orthodontic one), you can use cyanoacrylate adhesive or any epoxy adhesive.

If it is necessary to use orthodontic adhesive, you can follow the following steps steps:

1. Sandblast the metal bar with 100 microns or 150 microns aluminum oxide or do of grooving and pitting on metal bar to give some sort of mechanical retention.

2. Coat metal with one prime plus primer ormco. Follow the manufacturer instructions.

3. Use enlight adhesive ormco. Or any other orthodontic adhesive from any respectful company.

With regards..

Direct and indirect bonding

For what it is worth, I concur with the earlier opinions. 1) Not an abalone, drill holes on that shell, 2) the shells resemble Ostreidae but are quite worn. Further identification would be difficult.

some days before I called to the staff in one Korean bracket manufacture company.

And asked the reason why they made the bracket with torque in the face.

His answer is as follows;

1.as result of trial and error, we experienced the fracture and high profile of bracket when we make the bracket as torque in face. it is easy to satisfy many conditions when making slot torqued bracket.

2.communicating with many Korean Orthodontic professors, we had never heard of problem of slot torqued bracket.

And I practised simple confirmation for bracket torque with photograph.

In case of Damon upeer anterior braeket, the ormco company claim that their bracket is the bracket with base torque.

The condition of base torque bracket is that the center of slot and the center of the bracket base and the center of FA point is same.

But by my photographic measure they are not same.

By bracket positioner incorporated with bracket in Damon bracket it is possible to place the bracket in FA point. But if the standard is placed to the bracket base , the center of the slot is not coincident with the FA point.

So , My conclusion is that regardless the bracket is slot torque or base torque we may place the bracket right if  we place the bracket with coincidence of center of the slot and FA point.

How are your opinions, Drs?

If you look at the Centre  of Evidence Based Medicine (CEBM.net) what you will find is that the quality scale is applied to human clinical studies not to laboratory studies or basic science studies or in vitro studies.

The levels of evidence that have been described in the past are considered important relative to the design of the study and how it reduces the potential for bias in research. Laboratory studies may be acceptable or unacceptable based upon study design  but there really is not a grading scale for such studies. Likewise, without a grading scale, systematic reviews of in vitro studies  are not  appropriate. Indeed if you were performing a laboratory study part of the introduction to the study would be a review of the literature and part of the discussion of the study would be a review of the literature  but because the study is a laboratory study the results should remain consistent with previous studies of similar designs assuming that the original and the replication studies are all performed with reasonable care and integrity.

The final step of finishing therefore is appropriately called

"settling," since its purpose is to bring all teeth into a solid

occlusal relationship before the patient is placed in retention.

There are three ways to settle the occlusion:

1. By replacing the rectangular archwires at the very end of

treatment with light round arches that provide some

freedom for movement of the teeth (16mil in the l8-slot

appliance, 16 or l8mil in the 22-slot appliance) and

allowing the teeth to find their own occlusal level;

2. With laced posterior vertical elastics after removing the

posterior segmentso f the archwires;o r

3. After the bands and brackets have been removed, with the

use of a tooth positioner

By the sounds of your question/case it sounds as though your patient has DI. But you have also stated 'enamel hypoplasia', therefore is the situation DI or AI? If it is AI, I would recommend looking into the literature regarding 5% Sodium Hypochlorite pre-treatment of enamel prior to bonding in order to remove/denature proteins from the crystaline enamel structure. If your case however is DI, the effectiveness of dentin bonding - is unknown - and will be an issue for you, in areas of dentine. But in areas of enamel, again still in the DI scenario, bonding anything (brackets, composites, veneers) will be done so with the risk of enamel shearing away from the dentine. Further, your concerns regarding obliterated or filled in pulp spaces and reduced areas of enamel from attrition are pointing towards crown coverage and then providing orthodontic attachments to those. I hope I have answered some aspects of your question. I agree strongly with Agnieszka above for an interdisciplinary approach. Please post how it all goes.

Dear Fabio 

                     Thanks for giving to the point answer . Counter rotation was important aspect of preadjusted system in translation series brackets. Even Roth carried it forward. That is quite obvious in Roth writings of 70s and 80s. i don't know where and when the evolution came and even modern Roth prescription is without this feature. 

My Hypothesis is as under 

We are part of bandwagon and don't go in details of what we are using. We do orthodontics which manufacturer of brackets make us to do. Prescription is taken so simple that manufacturer make their own prescription . In a personal research i find out that Roth prescription values are written different  ever where . You wont find the same values in contemporary orthodontics By William Proffit ,Bristol Notes ,Dentaurum catalog and densply catalog. 

MBT prescription values in 3M and Dentaurum brackets are different . 

So we dont care and sometimes we dont know .We all have teachers they live in age of wire bending . So they say whatever come we will make final adjustment in wire bending.Some people don't want that art to die that's way bracket prescription is taken lightly.

Dear Haris

In his book "systemized orthodontic treatment mechanics", Dr Mclaughlin touches on the subject. This is what is said " Torque-in-base was an important issue with the first- and second-generation preadjusted brackets, because level slot

line-up was not possible with brackets designed with torque in-

face. Technology was not available to set bracket slots in

the correct position relative to the facial surfaces of the crowns

without torque-in-base. Modern bracket systems, including

the MBT™ system, have been developed using computer aided

design and computer-aided machining - the CAD-CAM

system. This allows more flexibility of design, not only to

place the slots in the correct position in the brackets, but also

to enhance bracket strength and features such as depth of tie

wing and labio-lingual profile. The computer is first able to

locate the precise location for the bracket slot, relative to

in-out distance and torque position for each tooth. Once this

position is established, it can then build up the 'in-fill' areas

to optimize all requirements of the brackets (Figs 2.6-2.8).

The brackets may be finished with all torque-in-base (full

size and clear) or with a combination of torque-in-base and

torque-in-face (mid-size) with absolutely no difference in slot

position. Since the advent of CAD-CAM bracket design, it is

not necessary to discuss this historical issue any longer!