On
Tooth fragment reattachment using acrylic/silicone guide

Fragment reattachment success depends mainly upon the extent of the fracture, the condition of the fragment and its adaptation to the remnant. The case simulated in this article presents a fracture involving enamel and dentin, with the fragment in excellent condition. 



 When performing reattachment, the first steps are performing the fragment and teeth on the prophylaxis and selecting a composite with shade matching with that of enamel. Then the adaptation of the fragment to the remnant is evaluated from the buccal and palatal aspects with an excellent adaptation and virtually without any loss of tooth structure. Then the analysis of the occlusal contacts is made in a maximal habitual intercuspation. 


⛔️ Note that they are clearly confined to the remnant not extending to the fracture line which will later be the bonding interface between the tooth and the fragment.
Under normal occlusal conditions, the existence of discrepancies between the contacts observed before and after bonding suggests that the fragment was bonded in a suitable position. Fragment reattachment is probably the one that most of its success depends upon adhesion. First of all the operative field has to be properly isolated using a rubber dam.
⛔️ The most critical step of bonding a tooth fragment is undoubtedly the correct placement at the moment the adhesive and the composite resin is light-cured. In order to avoid any mistakes, an acrylic or a silicone guide is prepared. With reference to the adjacent teeth to ensure optimal positioning of the fragment.
The first step in making the guide is carried out through the placement of the fragment into position and attaching it temporarily with a composite resin pellet placed at the tooth remnant-fragment in the interface and then proceed with light curing.
The next step is the isolation of the teeth adjacent to the fractured tooth with a water-soluble lubricant. Next, a bead of acrylic resin in the plastic phase is led against the incisal surfaces of the three teeth involving part of the buccal and palatal surfaces.
⛔️ It is important for the acrylic resin not to exceed the fracture line so as to allow for adequate removal of the excess composite while performing the bonding of the fragment.
After the complete polymerization of the acrylic, the composite pellet that held in place the fragment to the tooth remnant is removed and the acrylic guide is displaced towards the incisal aspect.
⛔️ Notice that the acrylic guide easily detaches from lubricated teeth, while maintaining the fragment that had not been isolated attached. Thus the guide is an important reference for the positioning of the bond and also facilitates the manipulation of the fragment while performing the adhesive procedures since its handling is generally difficult due to their tiny size. 


📝 During a fragment reattachment ;
1️⃣ The bonding procedures are performed separately. Firstly on the fragment and then on the tooth. Acid etching is performed on the entire surface to be bonded and extends approximately 1 to 2 mm towards the proximal, buccal and palatal surfaces. After 15 seconds the etchant is rinsed and the excess moisture is removed with air jets and cotton pellets, respecting the enamel and dentin substrates. The adhesive system is applied without light curing. At this point, the fragment is ready for bonding although the adhesive procedures have not yet been performed on the remnant.
⛔️ it is important that the fragment remains shielded from light to prevent premature curing of the adhesive layer.
2️⃣ In the tooth remnant, the procedures begin with the protection of the adjacent teeth with teflon tapes from the action of phosphoric acid and the adhesive system. The acid etching and adhesive system follow the same protocol as used on the fragment, and again 
⛔️ the adhesive is not light-cured as this moment.
Attention please ‼️ if the adhesive layer was light-cured on both the fragment and the tooth, the thickness of the adhesive film could prevent the correct fit between them during bonding. 

3️⃣ After bonding procedures, a composite with shade matching with enamel is applied on the fragment serving as a real luting agent. Then the assembly guide/fragment is led into position and stabilized by finger pressure. At this time, the ideal situation is that excesses of composite resin flow throughout the interface to ensure that all possible remaining spaces between the tooth and the fragment have been filled by the composite. Then the excesses are removed with a spatula or a brush and the guide/fragment assembly is light cured. Then the acrylic guide is displaced towards the incisal aspect and removed. In some cases where the fit between the remnant and the fragment is not perfect, composite resin may be added.


4️⃣ After removal of the guide, the excesses of the composite are carefully removed. For this task, the use of a #12 scalpel blade is indicated, flexible abrasive discs, finishing strips and abrasive rubbers according to the excess amount and its location. 
5️⃣ Polishing is now performed seeking to give the bonding interface a gloss similar to that of the tooth structure so that the transition of the fragment to the tooth remnant becomes visually unnoticeable. 


6️⃣ With the removal of the rubber dam, the occlusal contacts are checked and compared with those recorded prior to bonding. If there is a discrepancy between the contacts pre- and postoperatively, it is likely that the fragment has been bonded in an inappropriate position or that remaining excesses of the composite in the area of the margin, requiring the occlusal adjustments. 


👉🏻 Aesthetically, the result of a fragment reattachment is generally very pleasant. In no other way, it would be possible to restore so accurately function, form and natural texture so quickly in a conservative and biological manner. There is no - and neither ever will there be - a restorative material that overcomes the inherent advantages of keeping the natural tooth structure 🦷.

Stay tuned for the next post, we will discuss tooth fragment reattachment with beveling technique after reattachment.