By Lee Ann Brady, DMD 

A patient chipped a tooth on her lower hybrid denture and loosened an implant screw. The denture had been placed 18 years ago, so she had an old titanium bar with denture teeth and pink acrylic. That day, I put the screw back in and smoothed out where the tooth was chipped. During this visit we had a great conversation about the future of her hybrid denture. 

I have had a similar conversation with several patients in recent months. They have the original, traditional bar retained hybrid denture that is nearing the end of its lifespan. And so, what are the options? 

1. If the bar is in great shape, new denture teeth and a new denture base can be milled and placed over the existing titanium bar. 

1. Alternatively, we can get rid of the bar and go to something that is all zirconia. 

If there is a preference for the first option, the first requirement is to make sure the titanium bar is in good condition. After 18 years, we would take it off and have the laboratory examine it under microscopy.  

If converting to all-zirconia and the patient has had upper and lower dentures, we must consider if one arch can be converted without converting the second arch. A zirconia arch is going to wear an opposing original denture fast if there is parafunction, and the zirconia arch is likely to fracture the opposing original prosthetic teeth. 

We have options today we can think about with our patients, but many have in their minds that when they got their hybrid dentures years ago, the dentures would last. All the time, energy, and dollars to freshen up or replace their denture is a big deal to them. Shifting their mindset from “I thought I was done investing in dentistry” to “My denture is at the end of its lifespan” is a big hurdle. So, the earlier we can start those conversations before they need to invest, the easier they can transition their minds to accept care with grace when the time comes. 

When your bar retained hybrid denture patients visit for perio maintenance and your exams, inform them of the lifespan of their denture is at most 20 years and set expectations for discussing the best available options at some point in the future.  

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! 

How Ivoclean Works 

Lee Ann Brady, DMD 

Saliva on the inside of restoration surfaces greatly reduces the bond strength between the porcelain and the cement but during the intraoral try-in process, it is inevitable that there will be saliva contamination. 

Most dentists I know use Ivoclean from Ivoclar to clean their indirect restorations after try-in. It is an incredible material for removing saliva and other contaminants that the restoration is exposed to during the intraoral try-in process.  

We trust Ivoclean to fully remove resin or traditional cements, as well as saliva and red blood cells to produce a super pristine surface.  

Did you ever wonder how Ivoclean works to get rid of saliva and all the other debris that gets on the inside of a ceramic restoration or metal base?  

Intraoral contaminants contain lots of phosphates. Ivoclean contains suspended zirconia particles that have an affinity for phosphates. The zirconia particles pull towards them the phosphate-laden particles, so when you rinse off the Ivoclean, the intraoral debris is rinsed away leaving a clean surface. 

Note: We don’t want to expose zirconia restorations to something that contains phosphates or includes phosphoric on the label because there is a strong attraction at an elemental level between zirconia and phosphate particles. To neutralize the ionic bond between saliva phosphates and zirconia, we need an alkaline solution such as potassium hydroxide (KOH). This is the active ingredient in products such as ZirClean from BISCO. 

Restorative Notes on Bonding to Sclerotic Dentin and Removing All-Ceramic Crowns 

By Lee Ann Brady, DMD 

Bonding to Sclerotic Dentin 

Bonding to sclerotic dentin is difficult, if not close to impossible. If the lion’s share of the tooth’s surface is sclerotic, you may not have the longevity that you’re hoping for. I’m specifically thinking of some lower anterior restorative cases I’ve seen over the years, where the veneers just haven’t held up and we’ve had to go to full coverage. 

I don’t trust some of the self-etching adhesives to result in a strong bond on sclerotic dentin, even the newer ones in the eighth generation. Fortunately, one thing we don’t need to worry about is sensitivity because the dental tubules are closed. Since I’m not worried about sensitivity, I can apply the same techniques I would with enamel with the intent of improving the probability of a strong bond. I can do a light prep, get rid of the sclerotic surface, and etch it with phosphoric acid for 25 or 30 seconds. Alternatively, I can use 30- to 50-micron aluminum oxide in an abrasion unit.  

Removing All-Ceramic Crowns 

Removing dental crowns can be a delicate and time-consuming procedure. In a world of so many different materials, it’s helpful to have an idea of which bur to use and how long removing the crown could take. One of the biggest challenges is determining whether a crown is a lithium disilicate or zirconia restoration. The radiograph and visual inspection will give us clues but afterwards, we must go through a process to understand what may be involved. 

Our First Clue: Zirconia looks like metal on a radiograph, and lithium disilicate looks radiolucent like natural tooth structure.   

Our Second Clue: If the crown is partial coverage, it’s much more likely to be bonded and I plan to prep down the entire restoration.  

Lithium disilicate restorations are often easier to cut through or section but they could be bonded and impossible to remove in pieces. Even if we can cut four pieces, we may have extensive prepping to do.  

On the other hand, zirconia can be harder to cut through, especially the 3y or 4y variety. But at least once you get to the cement layer, you can normally break it into pieces and remove them instead of having to extensively prep the entire tooth.  

If the restoration is full coverage, I can easily remove it in sections. In this case, I attempt to make my cuts all the way from buccal to lingual across the occlusal surface without bothering to stop. At this stage, I can pick up a crown remover and apply some general pressure to crack it off. If the crown is not budging at all, I assume it is bonded to the tooth, and the next thing I do is pick up a big flat-top diamond to do my occlusal reduction as if I were prepping a natural tooth. Once all the occlusal is off the glass, the pieces on the buccal, lingual, and interproximal fall off.