Custom Rings Update

Tips and tricks - Direct posteriors
2013-10-20

This update is aimed to correct small flaws of the original article. 

Update (July 2017).- MyCustomRIng Kit has been released in partnership with Polydentia powered by Styleitaliano, to learn more, follow this link

As a solution, the proposed technique in this article “Custom Rings” is proven to be very effective. Historically, there were already similar techniques that can be confused with the “custom rings” technique, in 1981 form the book “textbook of Operative dentistry” by Baum/Phillips and Lund called “the non yielding matrix”, this technique had the objective of creating a super hard support for the matrix with acrylic in order to achieve extra contention for the amalgam condensation. The customizing material was applied only after the partial matrix was in place. Other historical techniques were found in the gold foil techniques by Tucker in order to contain the enormous amount of pressure applied during gold foil condensation, such techniques contemplated the use of acrylic resins, super hard impression compound materials, just to mention some. None of these techniques had the aim of copying the already natural and healthy teeth structures, all of these applied the material after the matrix were placed and not before, which is the main aim of this new development.

 

As a new development, our study group Styleitaliano developed the custom rings technique taking advantage of the simplest materials regarding wedges, rings and matrices in order to be able to personalize the ring embrasures to adapt the matrices in an anatomical and personalized way. The technique consists then on taking an impression with a photo-curing material (any light curing gingival material, block-out resin or flow composite) of the proximal embrasures of the teeth to restore and integrate them into the ring in order to be able to shutter perfectly wedge, matrices with a ring that will seal perfectly taking into advantage the anatomy of the healthy structures.

 

Indications

Class II composites, amalgams and gold foil restorations

Cases where intact anatomy of the impression area in mandatory

Teeth with medium and long clinical crowns

Any posterior cavity with a lack of axial wall where a matrix can be placed.

Big reconstructions where a matrix can be placed

 

Contraindications

Short and expulsive clinical crown.

Non intact anatomy found in the proximal embrasures.

Teeth where matrices cannot be placed.

When the previous situation is not convenient to be copied

 

Rules to follow for the custom rings to work:

– Impression must be carried out with the rubber dam and wedge on place (before cavity opening)

– Thin rings are advised (Original Palodent 3M, G-Rings with Standard Length or Composi-Tight® 3D Thin Tine G-Ring)

– Impression material ideally must be a gingival barrier, flowable composites are not advised because they are too stiff, but they are still useful.

– Sandblasting of the ring extremities are advised to have better resin fixation and less detachment problems.

– cavities must be filled up independently and matrix removed before next cavity is performed (in case of contiguous cavities) in order to achieve a very strong contact point.

 

Since its online publication, the custom rings technique is being taught in many universities and academies around the world. More than a 100 copies of the digital content in HD have been delivered to professors and lecturers who have requested it around the word.

The author wishes to thank Anna Salat and Jon Gurrea for their precious collaboration. The author wishes to express that the development of this technique was born during brainstorming with Dr. Walter Devoto and Prof. Angelo Putignano.

 

Fig. 1

Initial situation, showing a defective and fractured amalgam wich is going to be replaced with a direct adhesive restoration

Fig. 2

The quadrant under isolation

Fig. 3

Once the wooden wedge is placed, small amount of photocuring gingival barrier (opal dam, niveus, kool-dam, ena-dam) will be placed in contact with the proximal embrasures in order to copy the healthy and intact proximal walls. Note that if the amalgam was displaying more widely, this technique might have not be used. This is the main step from the update: At this stage, the small increment shall be polymerized in order to, achieve full polymerization and have a thicker and stronger reproduction area. At the same time, the ring will not touch the tooth, avoiding the common problem of having the smallest triangle detached from the impression.

Fig. 4

The previously sandblasted ring is placed over the polymerized impression material (liquid ruberdam) this will create an extra pressure of the system due to the wider opening of the ring (3-4 mm approx).

Fig. 5

Afterwards we will add some more liquid dam to embrace the ring and polymerize again. This way is more predictable, faster and the ring is more resistant. Wider rings can be used, although is proper to say that our experience has not been positive with other kind of rings. After polymerization the ring is easily detachable from the teeth.

Fig. 6

If by any chance the material used for the impression touched the wedge, is advisable to remove this excess with an abrasive disc, in order to allow perfect settling of the ring back in the cavity.

Fig. 7

After preparation, cleaning, caries removal and disinfection of the cavity we are ready to begin the matrix, wedge and ring insertion.

Fig. 8

A convex preformed matrix (in this case Garrison slick matrix) is inserted, and then a wedge of the same kind (or even the same wedge) that was used during preparation.

Fig. 9
Fig. 10

Reconstruction of the proximal wall, polymerization and removal of the ring and the matrix. Is not advised to remove the wedge. The matrix will come out when pulled out with some tweezers.

Fig. 11

The cavity is filled up in small increments to reduce polymerization stress and contraction, and achieve better conversion values.

Fig. 12

The final layer is finished with a sectional technique, in three increments (one for every cusp and one for the triangular crest).

Fig. 13

A small amount of dark brown stain was applied in order to copy the neighbor teeth.

Fig. 14

The restoration after finishing and polishing with Diamond twists SCL paste and goat brush.

Fig. 15

Occlusal control after rubber dam removal, repolishing can be done, but the polishing hard work was already done under rubberdam.

Fig. 16

One month control showing an acceptable integration.

 

Update (July 2017).- MyCustomRIng Kit has been released in partnership with Polydentia powered by Styleitaliano, to learn more, follow this link