Custom Rings 4 years anniversary
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The phrase "There is no ring that adapts better, in the whole world" can sound arrogant for someone to say. But this is not the case, a personalised solution will become an incredible precise and stable separation and fixation tool for the matrices. That is the way that Custom Rings was born, one day before starting a case, a copy of the healthy embrasures was done, fearing that they were going to be lost and then the placement of a ring was going to compromise the integrity of the matrices.
After 4 years of the first case and the first article published in www.styleitaliano.org, hundreds of cases have been published in styleitaliano facebook group, and taught in several Operative dentistry programs from univerisities around the globe. In short, Custom Rings came to stay.
We will show a simple case to illustrate the sequence and application. The biggest challenge in this case is of course not the size or the position of the margin, in a young patient the big problem is the short crowns, the embrassures are especially difficult to achieve an area with no composite excess and a tight contact as normally the rings are not stable and strong enough.
Fig 1.- A small carious lesion on mesial of the 16 on a young patient.
Fig 2.- The clinical aspect of the teeth barely show the lesion. We can take advantage of the healthy embrasures, in case these will be remove during cavity preparation and caries removal.
Fig 3.- Isolation of the case. Note how the rubberdam is perfectly inverted. This is not an excercise of vanity, but a necesary step in order to avoid the rubber dam trapment between the wedge and the tooth which may lead to troubles in the maerginal area.
Fig 4.- Always pre-wedge, make no exceptions when dealing with proximal lesions. When dealing with short crowns, we break the wedge in order to be able to customize the ring, without the consistent problem of loosing it or not having it tight enough.
Fig 5.- The wedge before cavity preparation gives several advantages as teeth separation, rubberdam protection, soft tissue relocation, hemostasis and margin position prediction. This is very comfortable for preparation.
Fig 6.- TIP: Customization over the broken wedge, this strategy is done in short crowns to be able to gain stability. After applying My Custom Resin (Polydentia, Switzerland) we polymerize. It is imperative to work with a proper material, a resin which is very hard, has quick polymerization, has a contrasting color and offers an excellent cohesion between the polymerized layers in order to avoid detachment of the material.
Fig 7.- We will place a MyRingClassico (Polydentia, Switzerland) over the first polymerized layer. It is imperative to do so in order o avoid the ring touching the tooth surface and the breakage of the resin. It is a common mistake to place the ring with the non polymerized resin.
Fig 8.- Lateral view of the ring over the first polymerized layer.
Fig 9.- An extra layer of resin is place afterwards to embrace the terminals. This conferes the customized ring an excellent resistance, estability and functonality. Now is time to detach the ring from its place.
Fig 10.- The detached ring should present the perfect copy of the embrassures and no fractured material.
Fig 11.- Cavity opening is done very near the proximal ridge, allowing us to easily locate the lesion, predict the opening of the external margins and most importantly, the ability to fininsh the cavity without touching the neighbor tooth.
Fig 12.- Location of the margins should preferrably be over enamel, but always over healthy tissues completely free of caries. The giginval margin has a magnificent position when is located at the level of the wedge, as it is the area where the matrix adapts better and the patient can clean best.
Fig 13.- After a shy stage of caries removal, the controversial use of caries detector is done. It is especially helpful to detect caries in non-logical places. The rest fo the caries removal is done very carefully, without water and with very slight touches to avoid heating the dentin. We can aprpreciate the healthy dentinin dry conditions.
Fig 14.- After the complete caries removal, we are ready to disinfect the cavity, remove the wedge and place the matrix.
Fig 15.- After removing the wedge it is advisable to keep it if possible, the wedges used during the customization and preparation stages save a lot of information, one one hand, the remain in the impresion of the customised ring, on the other hand the wedge has the trimming done during the preparation of the gingival margin, making this small piece, the best possible wedge.
Fig 16.- A black matrix was placed, it is advisable to use black matrices when the cervical tissues are white, and a silver matrix when the cervical tissues are dark, this guidelines are good to follow in order to spot better the adpatation of the matrices. Plastic matrices can be used as well, the authors prefer to use them in cases where the metallic ones suffer distortion, the plastic ones can return to the original shape without being ruined.
Fig 17.- The customized ring is ready to be placed back in the cavity embrasures with the matrix in place.
Fig 18.- Note how the customized ring makes the adaptation of the buccal and palatal margins perfect. Sometimes the contour of the matrix might seem strange (as in this case near to the buccal side) such strange foldings are generally normal. Double chack thew internal part of the matrix to be sure of not having a catastrophic deformation of the matrix, which is unusual, but possible with any kind of ring.
Fig 19.- Selective etching of the enamel, no etching of the dentin was performed. A universal adhesive was used (Scotchbond Universal, 3M)
Fig 20.- The build-up of the proximal wall was done with Body A3 (Filtek Supreme, 3M). The exact heigh of the wall was measured with the instrument "posterior misura".
Fig 21.- Posterior Misura is a smart instrument that has a "fork" side which allows measuring the proximal ridge of a healthy tooth and transfer it to the neighbour with extreme precision. The opposite side of the instrument has another terminal for another necesary fucntion described in the next steps..
Fig 22.- Aspect of the proximal wall after removing the ring and matrix.
Fig 23.- Cavity is filled with bulkfill material color A1 (Filtek Bulkfill, 3M) 1,5 mm away from the margin. This thickness is measured with the other end of the Posterior Misura.
Fig 24.- Posterior Misura is a 45º conicity profile wich has a protrusion of 1,5mm, this structure allows the instrument to lean over the inclination of the healthy enamel of posterior cusps and push the existing material of the cavity base away of the margin, providing a 1,5 mm space which has been proved to be optimal for modeling and color purposes.
Fig 25.- Aspect of the base built in Bulkfill material.
Fig 26.- A thorough polymerization was done to ensure excellent conversion at the cavity bottom.
Fig 27.- final layer was performed with an A3 body shade (Filtek, 3M)
Fig 28.- Occlusion control
Fig 29.- Immediate aspect after rubber dam removal and polishing of the restoration.
Fig 30.- One month control.
Fig 31.- One year recall.
32.- Thanks to the numerous requests, a kit with all the materials especifically designed to perfom the custom rings technique was developed in collaboration with Polydentia (Switzerland) in order to have a vast selection of matrices with different contrasts (Black, Silver and transparent) of all necessary sizes (molar and premolar), and the perfect thickness (thin), the ideal resin for ring customization, wedges and a very special ring. Available at Polydentia's website www.polydentia.ch
33.- My ring classico was developed especifically for this kit. It is a unique ring in NiTi wich holds it position and strenghth afte thousands of uses. The profile of the terminals allow not only the perfect customization and cleaning of the ring, but the insertion of an amazing tool developed especifically for this purpose and useful for many other appplications, probably the most interesting one is using it without attachments.
Fig 34.- When is not possible to obtain a customization of the ring, a new "Delta Tube" was projected. It can be used in several positions, allowing a great adaptation and tightness in most cases.
ConclusionsAfter 4 years of experience with this technique, authors can say that it is an optimal solution, unfortunately not applicable to 100% of the cases but to a vast majority, and when this is the case, many alternative solutions are available as a delta tube or a ring with silicone terminals. Authors wanted to add only weblink references, these at the same time, contain several indexed and non indexed references.