How to cement posterior crowns with 3M ESPE cements [VIDEO]

When it comes to the cementation of indirect restorations, there are many factors to consider. Sufficient working time, handling properties, ease of residual cement clean-up, color stability and overall esthetics, in addition to patient comfort during the process, are all important. However, the most essential attribute a cement must have is outstanding bond strength and durability. 

In general, resin cements offer the most optimal results when considering retention rates, as they are the least soluble, most durable and provide the highest bond strength to both the tooth substrate and restorative material. 3M™ ESPE™RelyX™ Ultimate Adhesive Resin Cement is an industry leader with regards to bond strength when compared to other cements. When paired with a universal adhesive, such as 3M™ ESPE™ Scotchbond™ Universal Adhesive, cementation becomes a simple two-component process, regardless of the indirect restorative material. Since Scotchbond Universal adhesive contains silane and MDP, the need for additional ceramic, zirconia and metal primers is eliminated.  

When selecting a cement, it’s important to consider the overall case to determine the right cement for the particular indication. Some cements are universal and are approved for all types of clinical indications, including all-ceramic veneers, glass/ceramic restorations and CAD/CAM restorations, as well as PFMs and full-metal restorations. Dentists should also consider the method of polymerization. Resin cements are available in light-cured only, self/auto-cured only and dual-cure systems. Many dentists prefer dual-cure resin cements because they can be light-cured when using thin or more transparent ceramic materials, yet also offer the assurance of definitive dark-cure polymerization when cementing restorations that are either too thick, dense or opaque for light polymerization alone.  

It’s also important to think about patient comfort after the restorations are cemented, and select a resin cement/adhesive combination that will eliminate as much post-operative sensitivity as possible. Finally, an important factor of a cement is the end esthetic result; therefore choosing a cement that offers a range of shades and opacities, remains color-stable long-term, and offers optical properties such as fluorescence that mimic natural tooth structure is vital to overall clinical success. The world-class esthetics – when combined with durability, fewer components and a shortened procedure time – made RelyX Ultimate an ideal cement choice for the presented case.

In this presented case, a 41-year-old female presented with failing restorations with open margins, the beginning of recurrent decay and subsequent fractures on tooth Nos. 18 and 19. She was experiencing sensitivity and discomfort and elected to have crowns placed on both teeth.

Watch this video to see Dr. Blank complete the presented case using 3M ESPE cements.

Conclusion

Cementation is a critical component in the indirect restoration procedure. The author had ample time to complete the procedure with the materials selected, and the new restorations had improved esthetic quality and eliminated the sensitivity the patient was experiencing prior to the procedure.

Selection of the hardest-working materials available helps to ensure restorations reach the highest possible bond strength, providing patients with the security of a strong and long-lasting restoration.

Step-by-Step Procedure

1) As was mentioned, a 41-year-old female presented with failing restorations with open margins, the beginning of recurrent decay and subsequent fractures on tooth Nos. 18 and 19 (Fig. 1). She was experiencing sensitivity and discomfort and elected to have crowns placed on both teeth.

2) A preliminary impression was taken of the unrestored teeth using a triple-tray with 3M™ ESPE™ Imprint™ 4 VPS Preliminary Impression Material. This was taken for use in the fabrication of the provisional restorations (Fig. 2).

3) Fig. 3 shows the completed all-ceramic crown preparations. A final impression was taken with 3M™ ESPE™ Imprint™ 4 VPS Super Quick Impression Material.

4) 3M™ ESPE™ Protemp™ Plus Temporization Material in Shade A was injected into the preliminary impression (Fig. 4) The preliminary impression was then re-seated in the patient’s mouth for two minutes (Fig. 5). 

5) The completed provisional restorations were cemented in a conventional fashion with temporary cement (Fig. 6). They were worn until the all-ceramic crowns (IPS e.max, Ivoclar Vivadent) were delivered from the lab and ready to be cemented (Fig. 7).

6) The provisional restorations were removed and the preparations were cleaned with a non-fluorinated pumice (Premier Dental Products) using a prophy cup (Fig. 8). The restorations were then checked for accurate fit and the cementation materials (RelyX Ultimate in Trans shade, Scotchbond Universal adhesive) were selected.

7) The adhesive was applied to the preparations, dwelled for 20 seconds for complete saturation, thinned and solvents evaporated with 5 seconds of air-thinning (Fig. 9). No light-curing was required.

8) Simultaneously, the adhesive was applied to coat the entire intaglio surface of the restorations after they were cleaned with acetone (Fig. 10). No additional silane was required. The adhesive was air-thinned to prevent pooling and evaporate the solvents (Fig. 11). No light-curing was required.

9) The cement was injected into the restorations and onto the margins with a spiral mixing tip, ensuring an even mixture while dispensing (Fig. 12). The crowns were then seated with pressure.

10) Fig. 13 shows partial polymerization was initiated during 1 to 3 seconds of exposure using a curing light (3M™ ESPE™ Elipar™ S-10 LED). Note: Do not prolong this wave-technique for more than 3 seconds or the excess cement will harden before removal.

11) The residual cement was removed during the gel state with a sickle scaler and floss (Figs. 14-15).

A final post-operative X-ray demonstrates excellent fit and seal of the seated crowns. The patient reported no post-operative sensitivity and was happy with the final result. 

About the author

Dr. Jeff Blank graduated from the Medical University of South  Carolina, College of Dental Medicine in 1989 and maintains a full-time private practice at the Carolina Smile Center in Fort Mill, S.C. He is the founder of New Millennium Education, which offers personalized mentoring programs for those seeking to advance their skills in esthetic and complex restorative dentistry. He has lectured extensively both domestically and abroad since 1998, published numerous clinical manuscripts and dental research, and is a Fellow and active member of numerous dental societies. For questions, comments, or to arrange for Dr. Blank to speak at your upcoming local, regional or national dental program, he can be reached at jblank@comporium.net or by visiting www.newmillenniumedu.com and www.carolinasmilecenter.com.