Modified Megabrasion

27 Jul 2016 - 18786

Enamel hypoplasia is a development defect produced by a disturbance in the formation of the organic enamel matrix. These kinds of lesions are clinically visible and aesthetically displeasing. There are some techniques that can be used to remove the dysplastic enamel layer. Micro-abrasion with or without home bleaching is recommended for localized enamel hypoplasia when the lesion affects only the external enamel layer. In these cases, Microabrasion is performed by several applications with an abrasive 6.6% hydrochloric acid paste (Opalustre, Ultradent) and a special rubber cup (OralCups, Ultradent). Microabrasion and resin infiltration is other strategy to be considered.

For deeper lesions a more invasive restorative approach using resin-composite might be necessary. This technique is known as Megabrasion. The Megabrasion Technique is performed with a diamond-coated bur under water-spray coolant. It allows us to remove deeper white opaque spots. The margins are beveled with fine diamond burs to improve both adhesion and esthetics prior to composite layering.

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Fig 31, 32, 33. Artistic pictures taken during 6 months recall.

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Fig 1. The patient presented “white spots” in the incisal third in both central incisors.

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Fig 2-3. Reducing exposure and increasing contrast of a cross-polarized picture may help us to identify lesions and match composite shades (5). Using Smile Lite with the live polarizing filter helps very much selecting the scene we want to capture with the camera or mobile device.

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Fig 4. Rubber dam isolation is imperative in any adhesive procedure.

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Fig 5. Sand blasting for lesion removal

This is the main tip of the article: Avoid the use of diamond burs. Instead we recommend a careful sandblasting with 25-40 microns aluminum oxide particles until lesion is removed. It can be a valuable alternative to bur removal without an unnecessary sacrifice of sound hard tissue. Heavy aspiration is recommended.

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Fig 6-7. Effect of sandblasting on enamel surface. Very often we don’t need to completely remove the lesions. Is very important to rehydrate with water the area in order to see precisely the real aspect of the enamel.

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Fig 8. After 20 seconds etching with 37% posphoric acid gel (Octacid, Clarben) rinse abundantly with water-spray for 30 seconds.

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Fig 9. After gentle air spray drying the chalky white appearance demonstrated a properly etched enamel surface.

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Fig 10-11. Next step involves hydrophobic light-cured bonding application (Optibond FL, Kerr) and light-curing for 20 seconds.

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Fig 12. A high translucent shade (WE Filtek supreme XTE) was applied with Applica spatula (LMArte, Styleitaliano).

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Fig 13. A paintbrush (Cosmedent 3, USA) may help us to adapt composite and profile anatomy.

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Fig 14. Restoration is isolated with a glycerine gel prior to final light-curing to eliminate the oxygen inhibited layer.

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Fig 15. 60 seconds final light curing using high-power light-emitting diode (Elipar Freelight 2, 3M Espe) light curing unit.

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Fig 16. After rubber dam removal composite excesses are eliminated with fine diamond burs and disks (Sof-Lex, 3M Espe)

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Fig 17,18. Secondary anatomy is defined using multi-blade tungsten burs (step 4 of Finishing style bur set)and silicone rubber points.

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Fig 19. A coarse grained bur is passed manually (not mounted in turbine) doing strong pressure to get a rich horizontal anatomy.

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Fig 20. Sof-Lex Spiral is used for polishing without losing the horizontal grooves created in the previous step.

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Fig 21. Final glossing is achieved using aluminum oxide paste (Shiny C Enamel Plus Micerium) with felt wheel.

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Fig 22. Immediate Black back ground control picture.

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Fig 23-24. Immediate cross-polarized control picture and deep-view control picture.

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Fig 25. A final esthetic control was performed after 2 weeks. Complete teeth rehydration shows perfect integration.

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Fig 26-27. Cross-polarized and deep view pictures 2 weeks post op.

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