Tag Archives: build up

The centripital layered build-up of a posterior direct composite resin

No matter how brilliant the Sydney dentist is, did you know that all composite restorations face as much as 5% polymerized shrinkage?

This phenomenon lead to:

  • Internal debonding and the inevitable dislodgement of the restoration.
  • Marginal openings that causes leaks and re-infection or recurrence.
  • Cuspal flexure and microfractures which causes consequent permanent deformation due to the load subjected by the restorative material.
  • Postoperative sensitivity that may be the result of tissue exposure due to microleakage.
  • Marginal staining, also caused by microleakage.
  • In the clinic, I make use of nanofilled composites to remedy these noted discrepancies with hybrid composites. Nanofilled restorative materials have particles that are as minute as 0.02 microns. With this, restorations are more successful, with recorded shrinkage as low as 1.6%. More so, it allows the dentist to create better restorations.

    The article below does not only count the number of benefits one can enjoy with nanofilled composites. It also discusses the importance of proper manipulation and layering. This technique involves the incremental addition of restorative material into a cavity. Instead of packing a bulk of composite into the tooth, the filling is brought in, little by little, in a technique called “layering”. With the use of a nanofilled composite, you already improve success rates; when you perform the layering technique, you increase polymerization depths, improve aesthetic results and decrease polymerization stress.

    This follows a precise process:

    Step 1: Shade selection. To ensure aesthetic satisfaction, proper shade is selected.

    Step 2: Rubber dam placement. Proper isolation of tooth is performed to improve results.

    Step 3: Preparation. Tooth is drilled to remove diseased tissue and to prepare it to receive the filling material.

    Step 4: Etching. Application of the etchant prepares the tooth to receive the bonding material. Successful etching improves success.

    Step 5: Internal Adaptation. Making use of flowable composite that better penetrates the tissues.

    Step 6: Incremental Layering. Composite resin is added in small amounts.

    Step 7: Building the Proximal Contact. If the restoration involves the proximal areas, the proximal contacts should be restored harmoniously.

    Step 8: Building the Artificial Dentin. Dentin composite is placed in the right shade.

    Step 9: Building enamel layer. Enamel composite is then provided in the right shade.

    Step 10: Occlusal staining. Whether you like it or not, it is done to satisfy aesthetic appeal.

    Step 11: Finishing and Polishing. The tooth is moulded and polished to mimic the appearance of the natural tooth.

    Step 12: Rebonding. For an even more impressive finish, additional shine is provided.

    This process is explained in much detail in the paper attached on this post.


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PORCELAIN VENEER PROVISIONALISATION

As a Sydney dentist, when I teach veneer provisional fabrication I teach a few different methods.

  • Direct buildup – a very small dot of etch is placed on the tooth in the mid-labial section and then bond is applied generously over the remaining preparation including the etched area and non- etched areas. This will allow sealing of the dentine so there is no sensitivity. Composite is then directly placed and sculpted into position to simulate the anatomy. This is best for a single or minimal amount of veneers. Please remember after removal of the provisional, a bur must be run over the etched area to remove any remaining composite that may be still bonded in the spot.
  • Bis-acryl provisionalisation conventional method. Using a putty key the temporary material is placed into the putty and placed over the prepared teeth. This is then removed and trimmed and cemented into position with temporary cement. This can be difficult due to the fact that these temporaries are thin and can break upon removal. It is recommended that a clear temporary resin cement like TempBond NE is used, as using an opaque cement can lead to very opaque looking veneer causing concern for the patient.

TempBond NE - sydney dentist

  • Shrink Wrap: Firstly the preparations are cleaned with chlorhexidine, and then a generous amount of desensitizer is used over the teeth, as this protocol does not involve cementation of the temporary veners. Using a putty key the temporary bis-acryl resin material (e.g. Protemp – 3M Espe, Luxatemp – DMG, Integrity- Denstply) is placed into the putty and placed over the prepared teeth, and as this polymerises the material undertoes shrinkage which “Shrink wraps” the temporary veneers onto the prepared teeth. Any excess is carefully removed best with multi-fluted carbide burs.

Shrink Wrap - sydney dentist

  • Spot Etch and Shrink Wrap: This is exactly the same technique as the shrink wrap but we add the spot- etch technique where avery small dot of etch is placed on the tooth in the mid-labial section and then bond is applied generously over the remaining preparation including the etched area and non- etched areas. The shrink-wrap technique then allows for the temporary material to bond to the etched area and the rest of the temporary is wrapped onto the teeth.

 spot-etch temporisation - sydney dentist

Each technique has advantages and disadvantages, however my favoured technique is the spot etch and shrink wrap technique as this ensures that the patient does not lose their temporary. Just remember that it can be more difficult to remove due to this being etched onto one specific area, so warn the patient, and also remember to go over the etched area with a bur upon removal of the temporaries to ensure that there is no remaining composite or adhesives stuck to the tooth. Once I have done this I like to use the Prepstart(air abrasion 27 micron Aluminium Oxide at 40 psi) to clean the tooth and prepare for adhesive processes.

prep start - Veneer - Sydney Dentist