By Karyn M. Halpern DMD, MS
A 45-year-old healthy male presented for a hygiene visit and exam without complaints. After a clinical and radiographic examination, large distal proximal caries was observed adjacent to a failing occlusal-lingual resin restoration on tooth #3. In addition, tooth #2 was diagnosed with both occlusal-lingual pit and fissure caries as well as mesial proximal decay (figures 1 and 2, below).
Upon being shown and advised of the findings, it was recommended to restore the large lesion on tooth #3 with a single-visit CEREC® onlay and restore the smaller lesion on tooth #2 with a direct resin restoration.
Figure 1: Tooth #3 failing occlusal-lingual resin and large distal recurrent decay
Figure 2: Radiographically evident proximal caries on tooth #2 mesial and #3 distal
The failing resin restoration on tooth #3 was removed, and the extensive distal decay was excavated. The remaining undermined and thin distal lingual cusp was prepared for cuspal coverage. Caries detector was applied to assist in verification of complete caries removal (figure 3, below). The pit and fissure caries on tooth #2 was removed, as well as the decay on the mesial wall that was accessed directly. G-aenial™ Universal Flo flowable composite was used to restore #2 mesial, occlusal-lingual, and was also placed on the pulpal floor of the preparation of tooth #3.
As with all CEREC® restorations, the key to success comes down to the preparation. For a partial coverage onlay, the preparation must have draw with no undercuts, especially in the interproximal box. The internal line angles should be round and smooth, with straight exit walls on the interproximal.
Figure 3: Onlay Preparation tooth #3 and application of caries detector to assist in caries removal
After the composite restoration on #2 and the preparation on #3 were complete, the lower jaw, upper jaw and buccal bite were recorded using the CEREC® Primescan in the Acquisition Phase. The virtual models were created and the margins on the virtual preparation were created using the auto margin finder crown using the CEREC® 5.2 software (Figure 4). Once the design was completed, the onlay restoration was fabricated using a CERASMART® 270 A2 LT block with Dentsply Sirona’s MCXL. It mills quickly and predictably without any marginal chipping (figure 5). It also saves time since no firing is needed.
Figure 4: Margination using auto margin finder
Figure 5: Milled margins without any marginal chipping
Once milled, the sprue was removed. The restoration was then trial seated, verifying margins were closed and the contact was checked with floss. The restoration was then characterized using the OPTIGLAZE™ Color red-brown stain in the occlusal fissures followed by a clear coat of OPTIGLAZE™ Color.
To deliver the onlay for final placement, G-CEM ONE™ self-adhesive resin cement was used in “Adhesive cement mode” by combining it with G-CEM ONE™ ADHESIVE ENHANCING PRIMER (“AEP”). AEP accelerates the chemical cure of the cement to allow for optimal bonding. It allows for extremely easy cleanup which makes it even more advantageous.
Once bonded into the tooth, the restoration margins blend seamlessly with the surrounding tooth structure (Figure 6, below).
Figure 6: Occlusal view of final seated CERASMART®270 A2 LT restoration #3 after cementation
This clinical case demonstrates how predictably and efficiently a partial coverage CEREC® onlay can be designed, fabricated, and placed in a single visit using CERASMART® 270 and G-CEM ONE™ resin cement. CERASMART®270 mills beautifully without chipping and saves significant chairside time, as no firing is needed. It can be characterized easily with OPTIAZE™ Color to match existing esthetic or simply polished and placed. When combined with G-CEM ONE™ with AEP, the result is a strong and esthetic restoration that blends seamlessly with the surrounding tooth structure.