Anterior interproximal caries is detected by transilluminating the teeth from the palatal side of the teeth, usually with the reflected light of the dental mirror. Further evidence of caries can be gained by using a DIAGNOdent or similar device I suppose.Once the diagnosis of caries is confirmed, a tooth-coloured composite should be used to restore the tooth.
Begin by anaesthetising the tooth, then using a high-speed drill, access the anaesthetised carious tooth by cutting through the enamel. Access the tooth from the palatal side if possible so that the appearance of the tooth is affected as little as possible. A small round bur is usually used for palatal access in the high speed. Now remove the carious enamel and dentine with a low speed drill. Stained dentine that isn't soft should be left alone. However, if there is so much healthy but stained dentine that the tooth is visibly darkened when looking at the patient, then some healthy tissue may need to be sacrificed to improve aesthetics. A bevelled margin is important, especially on incisal margins and larger two-surface restorations. Prepare some glass ionomer cement (GIC) and line the cavity with it. Next construct the composite restoration.
The composite restoration is constructed in four steps:
- First, apply mylar matrix strip and wedge the tooth to be restored, then acid etch the GIC-lined cavity to remove the microscopically small smear layer that blocks the dentinal tubules and to create porosities in the outer layer of enamel which allows micromechanical bonding between composite/adhesive and enamel.
- Second, apply the primer - the primer lowers the contact angle of the adhesive liquid, thus helping it spread over the cavity.
- Third, apply the adhesive (adhesive is the composite less the filler) to bridge the composite to the tooth and light cure it.
- Fourth, apply the composite in steps, light-curing between and after the final step. The mylar matrix strip is wrapped around the tooth to shape and merge the composite to the tooth correctly.
Hi, is it necessary to acid etch the GIC? I thought that the GIC made a chemical bond with the adhesive, rather than a mechanical. Would it not be better to etch before the GIC is applied? Thanks.
ReplyDeleteI would've thought so, but this is how I was taught to do it and I'm scared that if I do it any other way the world will end.
ReplyDeleteA small round bur is usually used for palatal access in the high speed.
ReplyDeleteA bevilled margin is important especially on incisal margins and larger 2 surface restorations.
And regarding the etchant, it is also to open enamel tubules to create a enamel-composite interface for micro-retention.
The adhesive must also be light cured.
The fine-finishing bur in the high speed creates an excellent finish on the composite.
The etchant is not to open up enamel rods. Enamel is made up of prisms, or rods, and the etchant creates porosities in the outer layer of enamel that allows micromechanical bonding between composite and enamel.
ReplyDeleteThanks heaps for the feedback. I have incorporated explanations into the body of the article.
ReplyDelete