Zirconia in Dentistry was first utilized in 2000’s as a consequence of its similarities to titanium when it comes to biocompatibility and power. It’s utilized in Orthopedics for making prosthetic joints and first utilized in Dentistry for making Crowns and bridges. Many consider Zirconia as a non steel however in actuality it’s a steel oxide. FCZir or Full contour zirconia crowns are extremely aesthetic much like lithium disilicate or Emax crowns. Zirconia is now being utilized in all instances – Bridges, Single unit crowns, Implant crowns or bridges and even Full mouth prosthesis.
The one main downside present in Zirconia is the dislodgement of Crowns in simply a few weeks as a consequence of problem in getting correct Bonding. For Bonding Ceramic or Steel Ceramic Crowns there isn’t a want to arrange the tooth or Crown floor however in Zirconia to get a correct Bond we have to put together each the inside floor of the Zirconia Crown and the Tooth floor.
In accordance with some research it have been discovered that the usage of Primer containing 10-MDP has exponentially elevated the bond power of Zirconia Crown. Sure cements resembling SpeedCem plus by Ivoclar has been seen to include MDP molecules within the self etching cement.
Steps to Bond Zirconia Crowns to Tooth:
We’re going to divide the protocol into 2 elements – getting ready the Crown and getting ready the tooth.
Getting ready the Tooth for bonding Zirconia Crown:
Isolate the tooth and put together it with 50 micron aluminum oxide or pumice utilizing Air Abrasion.
In case Enamel is current, it’s important to etch it utilizing phosphoric acid for 15-30 seconds and dry it.
Now apply Adhesive on the Dentin floor and unfold it evenly utilizing Air leaving it for 15-20 seconds (don’t gentle treatment)
Getting ready the Zirconia Crown for bonding:
As you’ll making an attempt the Zirconia crown on the ready tooth earlier than entering into for insertion to examine for the match and end, you will need to clear the Crown to take away any saliva or contaminants which could intrude within the bonding between the crown and the tooth.
Step 1: Clear the inside floor of the tooth utilizing an answer resembling Ivoclean from Ivoclar which removes any saliva, blood and many others. To wash with Ivoclean, place the liquid onto an applicator tip and place it on the inside floor of the crown and go away it for 20 seconds. Now rinse and dry it with Air.
It’s also possible to clear the Crown utilizing 5% Sodium Hypochlorite which has been discovered very efficient nearly much like utilizing Ivoclean and Ultrasonic Cleansing bathtub with Alcohol for five minutes.
Notice: Don’t use Phosphoric acid or Hydrofluoric acid to scrub Zirconia Crowns.
Step 2: Now a Primer needs to be positioned on the intaligo or inside floor of the crown. Just be sure you apply the primer solely to the inside floor and never cross the borders as cleansing it is going to be troublesome.
Step 3: Now utilizing the three means syringe, utilizing Air evenly distribute the primer onto the Crown.
Step 4: After getting ready the Crown Load the Cements – Mostly used Panavia V by Kurrary or SpeedCem plus by Ivoclar. into the Crown and place it on the tooth.
Notice: SpeedCem by Ivoclar or Unicem doesn’t want any adhesive as it’s a Self Etching cement.
Step 5: Now it’s important to Mild treatment the crown from all angles, all 4 sides on the Molars or simply Facial and Lingual within the Cuspids.
Step 6: Take away any extra Cement from the tooth floor and in addition from the interdental areas utilizing a Floss. I often place Glycerine across the margins which prevents any Oxygen inhibition layer from forming as completed with Composite.
Step 7: Now Treatment the Crown for 20 seconds on the Line Angles.
When in comparison with Self Etching cements, Resin bonded cements are extra dependable and have the strongest bond power. So in medical apply I exploit Resin Bonded cements to etch Zirconia Crown in tooth with quick medical peak whereas utilizing Self Etching cements in Anterior or tooth with good Crown size.
Now that we’ve got seen how one can correctly bond Zirconia Crown to the tooth, allow us to take a look at what precisely occurs throughout Bonding. Zirconia crown is made up of Zirconium Oxide and the oxide a part of the crown is what bonds with the phosphate of the Cements. For this reason correct cleansing of the crown earlier than inserting Adhesive is necessary as, Saliva comprises excessive quantities of Phosphates which if not cleaned correctly will bond the Oxide layer and intrude with the correct bonding of Zirconia crown utilizing the Resin or Self Etching Cements.
Cleansing of the Zirconia Floor is necessary and Ivoclean is among the greatest supplies which is used to scrub. How does Ivoclean Work – It comprises focus of Zirconia oxide particles which creates a focus gradient, the phosphates from Saliva which have been on the tooth floor bond to the zirconium oxide in Ivoclean and are eliminated. The phosphates are the principle culprits isn’t bonding the Zirconium crown to the tooth.
