Lee Ann Brady, DMD 

I’m a big fan of retraction pastes, which are aluminum-based hemostatic agents. Their attributes make them highly effective when I need them, but they are also technique sensitive. 

• They are great for hemostasis within sixty seconds
• For a stringent retraction, you can leave them in place for two to five minutes
• They are so thick and viscous you can see them and easily rinse them off
• They do not cause prep discoloration like liquid hemostatic agents do
• They can interfere with the set of VPS or polyether impression materials but are less likely to do that than the liquids because they are so easily rinsed off

We must still be careful, though, to remove retraction paste from the sulcus. If residue is left behind, the impression material will not fully polymerize around the margin. So, while I love retraction pastes for hemostasis, I don’t use them unless I need them. I still prefer a two-cord technique using plain cord and epinephrine. When I do use a retraction paste, I am extremely methodical about rinsing the paste out of the sulcus. 

By Lee Ann Brady, DMD 

When a crown comes off and we are going to put it back in the mouth, we need to remove the old resin cement that is inside the crown. What is the best way to go about this? 

First, we need to know if the crown is made of zirconia or lithium disilicate. If you have a radiograph of that restoration, you can tell immediately which one of those two things it is. If you don’t, you can always attempt to X-ray it. (That’s what I do.) Alternatively, you can assume the crown is made of lithium disilicate, which is the more technique-sensitive material when it comes to removing cement. 

For crowns confirmed to be zirconia, employing 30-micron aluminum oxide air abrasion effectively clears out the old resin cement. Subsequently, re-etching the inside of the zirconia prepares it for reseating. For crowns presumed to be lithium disilicate, this approach should be avoided to prevent crack propagation. 

In the case of lithium disilicate crowns, two alternative methods can be employed: 

1. The crown can be placed in a porcelain oven to liquefy and evaporate the old resin. However, caution must be exercised to avoid rapid heating of the hydrated ceramic that has been in the oral environment. Rapid dehydration will introduce cracks and lead to crown fracturing. 

1. An alternative method involves using a brown silicone point in a high-speed handpiece, adjusted to lowest speed. A brown silicone point at slow speed effectively removes resin without damaging ceramic. 

How will you know when all the resin has been removed? When etching lithium disilicate, whether using red 5% hydrofluoric acid or Monobond Etch & Prime from Ivoclar Vivadent, any remaining resin will be evident because the dye sticks to it after the etching solution is rinsed off.  

By Lee Ann Brady, DMD 

For addressing the access hole of a screw-retained implant crown, my preferred method involves applying Teflon tape over the hole followed by temporary filling material, such as Telio Inlay from Ivoclar Vivadent. 

I emphasize to patients the importance of maintaining accessibility to the screw for potential adjustments without jeopardizing the integrity of the ceramic crown. Hence, immediately after seating the crown, I ensure no adjustments are needed before doing the filling. 

Patients are scheduled for a final post-op appointment with the surgeon after the restoration is in place. If there are no issues requiring crown removal, the Teflon tape and Telio Inlay may remain indefinitely, monitored during hygiene recall appointments. As long as the temporary filling remains intact, replacement is unnecessary. 

In cases where the Telio Inlay dislodges but the Teflon tape remains intact, I inform the patient of our plan to reapply the temporary filling. However, if repeated dislodgment occurs, leading to inconvenience, we consider transitioning to a permanent filling. In such instances, fresh Teflon tape is applied, and the access hole is filled with composite that precisely matches the crown’s color. 

Even if years pass and the Telio Inlay needs replacement, I opt for a temporary filling for ease of identification if removal is necessary. Only if frequent filling replacements prove bothersome do I consider switching to a permanent filling because I prioritize easy retrievability of the screw. 

Kelley Brummett, DMD 

Resin-based temporary cements are wonderful due to their translucency and their ease of cleanup after light curing. My favorite is TempoCem from DMG.  

To prevent resin-based temporary cement from bonding to the newly placed composite, some dentists apply Vaseline on the prep before placing the provisional. 

Instead of Vaseline, I use glycerin. We keep glycerin in a little syringe in the room, and we put just a smidge in a little dapping dish so I can coat the top of the prep with it. Since beginning to use glycerin, I have not had difficulty retrieving bonded provisionals. 

If your provisionals come off, just get a new and stronger temporary cement. No! I am just kidding! If the provisional comes loose, it is often because you do not have enough space, so excursive interferences are high. When this happens, I engage with the patient in checking their occlusion, and continue to work out the determinants of their occlusion.  

Figuring these things out while the patient is in a provisional that is retrievable due to the ease of the temporary cement used, helps me continue to make progress on their occlusion before moving forward with the final restoration.  

It is not a failure of cement; it is a growth opportunity for discovery and patient engagement! 

Christopher Mazzola, DDS 

This is an example of a clinical study that can help us in our everyday practice of dentistry. Although the findings do not surprise us, keeping the findings in mind will guide us in decisions we make when performing treatments our patients are counting on to be long lasting. 

Dr. Markus Blatz is co-founder and past President of the International Academy for Adhesive Dentistry (IAAD) and Chairman of the Department of Preventive and Restorative Sciences and Assistant Dean for Digital Innovation and Professional Development at the University of Pennsylvania School of Dental Medicine in Philadelphia. He and a research team from the University of Coimbra, in Portugal, studied the effect of rubber dam isolation on bond strength to enamel. Their goal was to test two hypotheses. 

Hypothesis 1: Rubber dam isolation improves sheer bond strength independent of the adhesive system used. 

Hypothesis 2: A highly filled 3-step etch and rinse adhesive will provide higher bond strength values than an isopropyl-based universal adhesive. 

For their tests, they used OptiBond FL from Kerr for the 3-step etch and rinse adhesive and Prime & Bond Universal Adhesive for the isopropyl-based universal adhesive. 

The mesial, distal, lingual, and vestibular enamel surfaces of thirty human third molars were prepared (total n = 120 surfaces). A custom splint was made to fit a volunteer’s maxilla, holding the specimens in place in the oral cavity. Four composite resin cylinders were bonded to each tooth with one of two bonding agents (OptiBond FL and Prime & Bond) with or without rubber dam isolation. Shear bond strength was tested in a universal testing machine and failure modes were assessed. 

Both hypotheses were supported by the results reported in the Journal of Esthetic and Restorative Dentistry in November of 2022. 

• With the rubber dam in place, both of the adhesives performed better than without the rubber dam in place, resulting in approximately twice as much shear bond strength with the rubber dam. 
• The 3-step OptiBond FL system resulted in a more resilient bond than the Prime & Bond Universal adhesive. The OptiBond FL group with rubber dam presented the highest mean bond strength values. Fracture modes for specimens bonded without rubber dam isolation were adhesive and cohesive within enamel, while rubber dam experimental groups revealed only cohesive fractures. 

For the benefit of our patients, we shouldn’t cut corners that will impact the longevity of a restoration. My thoughts are that whenever we have basic pure enamel bonding it should be under a rubber dam, using a total etch, 3-step adhesive system. But considering dentin likes to be moist, we may need to make other clinical judgments.