Post-endodontic restoration of a tooth plays a key role in the tooth‘s long-term prognosis. In many cases, endodontically treated teeth have significant hard tissue deficits that severely weaken the tooth‘s structure. The causes include carious lesions, which in most cases precipitate the endodontic treatment due to their extensive nature, as well as the endodontic treatment
itself. Creating a suitable access cavity, preparing the canal and the subsequent placement of a root post, which is frequently required to retain
an adhesive core build-up, lead to extensive substance loss and, in most cases, make crowning inevitable. In this context, the final margin must be
situated in the hard tissue and must encircle the build-up with a depth of 1.5mm (ferrule effect). This ensures that the final restoration can also withstand tilting forces. However, maintaining the ferrule design contradicts the maintenance of the biological width, which describes the distance from the sulcular epithelium to the alveolar bone, reported as 2mm in the literature. To achieve successful long-term restoration, it is extremely important to maintain both of these parameters.
Today, modern dental technology provides a wide array of materials and manufacturing techniques for fabricating individual crowns, which allows the most appropriate starting situation to be selected. For aesthetic reasons, we are increasingly using allceramic systems. In the following case, for the restoration we chose an allceramic zirconia crown and adhesive luting to ensure resilience and stability.
Materials used
This case study demonstrates the handling of the innovative self-adhesive PermaCem 2.0 luting cement.
Case study
A 30-year-old male patient presented to our out-patient department. Endodontic treatment had been performed on tooth 25, which had already been restored with an adhesive build-up one year earlier. The reason for this particular visit was a partial fracture of the crown on tooth 25, for which I first placed a temporary (fig 1). The plans for the final restoration included the use of an adhesive post and a crown.
For aesthetic reasons, the patient requested an all-ceramic restoration. We recommended and planned a zirconia crown to ensure stability and aesthetics.
Prior to preparation, we took a preliminary impression. After the tooth had been fitted with an adhesive post and core, it was prepared for crowning (fig 2) and a final impression taken using the double-mix technique (fig 3). To protect the prepared core, a direct temporary was fabricated from Luxatemp Star and cemented temporarily (figs 4 and 5). The dental technician used the double-mix impression as the basis for fabricating the crown, which consisted of a zirconia core fabricated using a CAD/CAM technique and a silicate ceramic veneer layer applied manually. The fit of the finished crown was checked, and it was prepared for placement as follows.
We decided to complete the restoration using the innovative PermaCem 2.0 self-adhesive luting cement. Consequently, the fitting surface of the crown first had to be sandblasted (fig 6), then cleaned with alcohol and dried (fig 7). Here, the innovative system‘s benefits are clear, since it completely eliminates steps such as etching, priming and bonding of the core. Preparation for cementing the crown is quick and easy, with a straightforward procedure that can be performed chairside. The cement comes in a very convenient Smartmix syringe that eliminates the need for hand-mixing by an assistant. The cement is immediately ready to use and can be applied to the dried crown directly with the exact amount required. Thanks to the stability of the material, it can be applied accurately to the inner crown surface and can be used without dripping or unnecessary material loss. Once the crown has been placed on the prepared core, pressure is applied. This displaces the material and causes it to flow due to its thixotropic properties. This ensures that the luting cement fills in the cement line completely (fig 8). Removing the excess material afterwards with a scaler is quick and easy (fig 9). Figure 10 depicts the definitively cemented single crown 25.
Conclusions
This user report demonstrates how simple and straightforward adhesive luting for all-ceramic systems is today. Thanks to its precise stability and flowability initiated by pressure, combined with simple application and removal of excess material, this innovative self-adhesive luting cement truly enhances the existing product portfolio. With its self-adhesive properties, PermaCem 2.0 helps to streamline procedures and, in so doing, minimises the impact of individual errors on adhesive luting.