Fragment reattachment and post reattachment bevel
When coronal fracture occurs in anterior teeth, fragment reattachment can be a valid alternative to a direct restoration. If the fragment is available, it should be kept in a liquid environment to prevent dehydration, thus allowing a more aesthetic result after the reattachment procedure. If the fragment fits well enough, it should be reattached as it is; only after the reattachment procedure the margin should be opened with a round bur to create a double bevel on the tooth and on the fragment. This procedure is also known as post-reattachment bevel, and it will ensure esthetic results together with an increased resistance to dislocation of the fragment.
In a paper we published in 2011 (Evaluation of the fracture resistance of reattached incisal fragments using different materials and techniques. Chazine et al, Dent Traum 2011), the influence of the material and the technique used to reattach the fragment was evaluated using a shear bond strength test. Pure Adhesive, flowable composite, regular composite and dual curing resin cement were used to reattach 80 fragments. Another variable was the use or not of a post reattachment procedure as demonstrated in this article. The choice of material seemed to have no influence on the test, whereas a bevel performed on the buccal surface could significantly improve the Shear bond strength of the reattached fragment, independently of the material used for the reattachment procedure.
Tommaso, 8 years old, had a traumatic accident 2 years ago causing the fracture of tooth #2.1, which was restored in another dental office. Last august he had an additional trauma resulting in the fracture of tooth #1.1. This time the fragment was available. In the first part of this clinical case, the fragment reattachment and the margin hiding procedure is performed. In a future article the direct restoration of #2.1 will also be described.
The initial situation in occlusion
The fragment, kept in milk, is correctly hydrated.
Another view of the initial situation
The stability of the fragment is checked.
After rubber dam isolation, the fragment is stable but part of the margin and of the mesial wall is missing
No preparation is performed before the fragment reattachment. This will keep the fitting to allow for a stable repositioning of the fragment
Enamel selective etching on the fragment
Enamel selective etching on the tooth after transparent matrix application
Adhesive procedures on the fragment
Adhesive procedures on the tooth
A flowable material is used to reattach the fragment. Heated composite, only adhesive, or a dual curing resin cement would have been a correct alternative as well. See Chazine et al Dent Traum 2011
Margin is opened with a diamond round bur. This technique is also called post reattachment bevel. (Chazine et al Dent Traum 2011)
The margin opened
Etching of the margin
application of a layer of enamel composite after a first layer of opaque flowable material
Composite adaptation is achieved with the use of a brush slightly wetted with modeling resin
After final curing.
Finishing is performed with a low speed diamond bur. It allows to smoothen the buccal surface in a predictable way. If water cooling is not used (like in this case), a blow of air will reduce the heat generated by the bur on the surface
After contouring finishing and polishing, before rubber dam removal
After rubber dam removal. Teeth are dehydrated.
The final result after rehydration.