March 2021

Question:  For the case example presented above, why did you choose to use a self-adhesive resin cement over other possible materials?

I was able to achieve proper occlusal taper and had adequate prep height for this case. By accomplishing this, I probably could have chosen from several potential cements. However, self-adhesive resin cements (SARC) offer clinical advantages over conventional cements (eg, zinc phosphate, zinc polycarboxylate, and glass ionomers) as well as adhesive resin cements (ie, cements that require additional pretreatment of tooth structure).

These include:

  • SARCs have better physical properties compared to conventional cements.

  • The dispensing and handling of SARC is easy. Several formulations of SARC exist including capsules, hand-mixed paste-paste, and automix paste-paste.

  • They are self-adhesive without pretreatment of the prepared tooth and require no additional bonding step. Because multiple- step adhesive resin cements are technique sensitive, the single-step application of SARC is a viable alternative for glass ceramic restorations and zirconia restorations.

    The bond generated by SARC has been found to be similar on dentin to adhesive resin cements. However, for maximum performance on enamel, it has been suggested that a selective enamel etching technique using 37% phosphoric acid be used. In this case, enamel margins should be etched for fifteen seconds followed by water rinsing to completely remove the acid.

  • SARCs are dual-cured. The setting reaction of SARC can be initiated both chemically (self-cure) and by light exposure (light curing).  Interestingly, the degree of conversion of monomers to polymers will influence the performance of SARC.  It has been reported that immediate higher degree of conversion, improved mechanical properties, and decreased solubility can be achieved if SARCs are activated via dual curing.  Clinically this can be achieved first by tack curing the material and cleaning excess cement within a gel phase window (ie, within the working time of the material) followed by definitive light curing of twenty seconds per surface.

  • SARCs are associated with a low incidence of post-operative sensitivity. Compared to the classic total-etch technique of adhesive cementation, the misuse or overuse of phosphoric acid can remove the smear layer and open dentinal tubules creating a pathway for bacteria and monomers to penetrate the pulp. In general self-adhesive resin cements have less influence on the dental pulp than other cement categories, including zinc phosphate, glass ionomers, and total-etch systems.

ZR-Cem™ is an innovative self-adhesive universal resin cement specially formulated for zirconia restorations.