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. 

The more complex the dental treatment plan gets, the more challenging the process becomes. Adding in interdisciplinary care with multiple specialists adds another layer of complexity. We need to clearly plan our sections, and clearly communicate the outcomes we hope for from the other providers.

The Challenges

One of the challenges has been communicating to my orthodontist my visual for the results. The other challenge has been how to visualize tooth movement to optimize my restorative. What has helped me tremendously is doing an ortho setup as well as a restorative wax-up.

My Process

This is a process I use when planning complex cases involving orthodontic and restorative that has helped create clear expectations for everyone.

1. I start my aesthetic treatment planning by drawing white shapes and lines on photographs of the teeth to determine the desired tooth proportions and gingival aesthetics. I’ve blogged about this before in these two articles: Tooth Proportion Aesthetic Ratio and Where the Pink Should Be. I also draw lines on photographs to determine the Anterior Segment Aesthetic Ratio.
2. When a complex restorative case involves orthodontics, I want a clear sense from my white lines of where I want the teeth moved so I can optimize my restorative. I will send a set of preoperative models to the laboratory and ask them to do an ortho setup. Multiple copies of the ortho setup allow us to move the teeth and do a restorative wax-up on the moved teeth. Once I examine the wax-up I decide if the teeth look the way I visualized they would. Do they have the right length to width ratios? Do they have all gingival margins in the right positions? If I were to just do a carved restorative wax-up, I wouldn’t understand if the tooth movement is helpful. If you are not familiar with ortho setups, I recommend reading this article from 2012.
3. Once I have the teeth positioned in an ortho model the way I think will be best for my restorative, I send my orthodontist the model to communicate exactly where I want the teeth moved. The orthodontist provides feedback on what will be involved to get those movements. Based on that, I can balance the risks and benefits of alternative treatment plans and discuss with the orthodontist whether restorative treatment should occur at the very end of orthodontics or be done in phases during orthodontic treatment.

Before I come up with a treatment plan, I always do certain things in a certain order. That structure has allowed me to feel confident that I can treatment plan any case that walks into my office. That structure, or process, affects how I approach my exam, make my diagnosis, and ultimately make my treatment plan.

The process begins by looking at the following five areas during the patient exam. I gather information in each of these areas in the following order:

1. The patient parameters of the case
2. The aesthetic parameters of the case
3. The functional parameters of the case
4. The restorative parameters of the case
5. The biologic parameters of the case

The first area I look at is the patient. What is the patient interested in? What are the patient’s circumstances, temperament, and dental health objectives? What is the patient’s current understanding of their dental health? How does that compare to my perception of their dental health? After answering these questions, I then move on to the four technical areas.

The first technical area I look at is the aesthetics of the teeth, gingiva, skeletal structure, and face. I then look at function, including the jaw joints, muscles, occlusion, and airway. The third area I look at is the restorative parameters of tooth structure, missing teeth, and the restorative materials and restorative techniques previously used in the mouth. And finally, I look at the biologic parameters, including caries, periodontal, and endo.

When I do my examination, I want information gathered in all five of these areas. When I sit down to do my exam diagnosis and treatment planning, I have all of that information in front of me and I’m going to always consider the five areas in the same order as I proceed with diagnosis and begin treatment planning.

When I plan the stages of treatment that will occur, the treatment sequence is in the order that is most appropriate for the case. For example, if the patient has a biologic health condition, perhaps, the need for a root canal or significant perio inflammation, I’m going to treat that condition at the front end of the treatment sequence, and not in the order in which I gathered information and reviewed it. The most appropriate treatment sequence will be the order in which I need to do restorative procedures to most predictably achieve the total best outcome.

Although my “structured approach” may not be the same as yours, I thought sharing mine with you could be of benefit to you. By establishing a process in which you gather and consider information in all five areas (Patient, Aesthetics, Function, Restorative, and Biologic), you will have all the information you need to consistently do diagnosis and treatment planning with efficiency and confidence.

For more information on this topic, I encourage you to take Treatment Planning and Case Presentation with me on June 11th – June 12th. This is a phenomenal way to solidify your knowledge and spend two days in sunny Key Biscayne, FL.

How long does a dental crown last? The answer is, “It depends.” In this blog, I will review how I manage answering this question for my own peace of mind and to reduce disappointment for my patients.

All of us can think about crowns that are currently in our patients’ mouths that have been in four decades or more…crowns that are doing fine. Sometimes, we look at a bite wing of one of these restored teeth and see space enough “to drive a truck” between the margin and the natural tooth structure. Yet, the crowned tooth is fine with no caries.

We also can think about crowns in our patients’ mouths that needed to be or now need to be replaced within five years or under…perhaps, even within two years. Some of these crowns were carefully and beautifully done.

We have a habit of thinking: The better our skill is, the greater is the longevity of the crown. We need to get away from this generalization because there are numerous factors that impact longevity.

Yes, the dentist’s skill is a factor as are the amount of time and energy we put into making it exquisite, the quality of the laboratory, and the materials. But the other part of the equation is that we put dentistry into the mouths of human beings, and human beings come with risk factors. The most common reason we replace a crown or filling is recurring caries. We see some patients who have new carious lesions every time we see them in the dental chair. They are at high risk. At the other end of the spectrum, we have patients who have not had a carious lesion in multiple decades. The functional risk of the patient is the second primary risk factor. We have patients who can break any type of crown, and we have other patients who have no evidence of functional risk.

What do I say to my patients? I tell them dentistry does not last forever, and there are challenges in predicting the lifespan of their restorations. I do not say, “When your crown fails at some point in the future, it will need dental treatment again.” Instead, I say, “We’re going to treat this tooth with a crown. At some time in the future, it will need treatment again.” Then I say, “The most common reason why a crown needs to be replaced is dental decay around and under the crown, and what we know about you is that you tend to get cavities [or not get cavities]. The second most common reason we replace crowns is that they break. The materials cannot withstand the forces. And what we know about you is that you are tougher on your teeth [or not as tough on your teeth] compared to many other people. “

This type of conversation makes most dentists nervous. They fear the patient will not want to do the crown if the patient knows they will eventually need to retreat the tooth. That has not been my experience. The reality that cars do not run forever does not stop us from buying a new car. The knowledge that your roof will last 10 to 14 years does not stop us from replacing the roof. The reality that the tooth will need retreatment in the future does not stop us from having it treated now.

Setting realistic expectations results in less patient frustration, sadness, and disappointment. It also lessens conflict between the dentist and patients. I want my patients to understand the reality that dentistry does not last forever. It all has a lifespan, just like a car or washing machine. Any tooth we treat will need to be treated again. I also want them to know their risk factors for decay or breakage relative to other patients. Is it high? Is it low? Is it somewhere in between? We can then have a conversation about what they can do and what we can do together to minimize those risk factors.

Ferrule is a critical factor in being able to plan the prosthodontic phase of treatment for an anterior tooth that has had endodontic therapy. It is also an ingredient in predicting the longevity of the tooth and restoration. Yet, given this level of importance, it is often misunderstood and overlooked.

What is tooth ferrule?

Ferrule is the amount of natural tooth structure we have left on an anterior tooth on which we are going to do a post-core and crown. Knowing the amount is integral to knowing how we are going to seat the crown and it gives us ballpark information about the longevity of that restoration. We look at the natural tooth structure of the tooth on the buccal and the lingual.

The amounts of the natural tooth that are left on the mesial and distal don’t matter. We don’t measure them. They don’t help us at all with retention and longevity.

On the buccal and lingual, we look at the height of the natural tooth structure, measuring from the margin of the crown prep up to where the core starts. We also look at the thickness of that natural tooth structure, measuring from the outside surface of the crown prep to the inner surface where the post space begins. We measure the height and thickness, both buccal and lingual. We then use the smallest number. If we have less tooth structure on the lingual, then the ferrule is determined on the lingual. If we have less thickness than we have height, then the ferrule is determined by the thickness.

Wherever the place is where we have the least natural tooth structure, that now becomes the ferrule we use when we start to think about how we are going to treat this natural anterior tooth.

How does ferrule impact restorative decisions?

The amount of ferrule impacts restorative decisions such as:

• Bonding versus cementing the post
• Bonding versus cementing the crown
• Doing a post at all
• Predicting longevity after restoration

Guidance for these decisions has been formed from substantial research published by the University of Washington School of Dentistry in Seattle that looks at the longevity of the post-core based on the amount of ferrule and whether we bond or cement.

If we have minimum ferrule (1.0 to 2.0 mm) and we want to get the maximum longevity for the anterior restoration, we should bond the post-core and then bond the crown with a dual-cure resin bond system that adds strength to the restorative material, like NX3 Nexus™ Dual Cure from Kerr, Multilink® Automix from Ivoclar Vivadent, or G-CEM LinkForce® from GC America. There are lots of choices of systems you can use, but we need to etch, prime, and bond for high bond strength. We need to keep in mind that even though we are increasing the longevity of the restoration by bonding, the restoration on minimal ferrule will not last as long as a restoration on a greater amount of ferrule.

If we have 2.0 to 3.0 mm of ferrule, we can choose whether to bond the post-core and cement the crown or to cement the post-core and bond the crown to get the same longevity as the tooth with 1.0 to 2.0 mm of ferrule treated by bonding both the post-core and crown. When we have 2.0 to 3.0 mm of ferrule, we can increase the longevity of the restoration even more if we bond both the post-core and crown.

If we have greater than 3.0 mm ferrule, we can cement both pieces without affecting longevity.

If we have 4.0 mm or greater of ferrule, the question becomes whether we need to do a post-core on this tooth or do a fully bonded restoration.

Key Points to Remember

• The amount of ferrule we have has a strong impact on the longevity of the restoration.
• We can increase the longevity when we have less ferrule by bonding both pieces, the post-core, and the crown.
• When we have very little ferrule, we need to understand that we have a reduced longevity for the post-core restoration, even in the face of bonding.
• The amount of ferrule is one of the strongest indicators of how long an anterior crown will last, as well as whether we have bonded or cemented. How long a crown will last involves additional factors I will discuss in another blog, How Long Do Crowns Last?

One of my goals with composite restorations is to do as much of the forming and shaping prior to picking up a curing light as I can.

The material is easy to sculpt before it is cured, and access to the surface of the tooth is easier with hand instruments. Once I have placed all the composite and have a dense fill, I remove as much of the excess sitting above the final occlusal surface as I can. With this step accomplished, I turn my attention to creating the occlusal anatomy.

My OptraSculpt handle and disposable tips from Ivoclar Vivadent are perfect for this. The various tip shapes allow me to create incline planes, occlusal grooves and the curve of the marginal ridges into the occlusal embrasures. This process often removes and shapes the composite. My assistant holds a two by two that has been moistened with rubbing alcohol to remove the excess off the end of the instrument. I can place a different shape on each end of the instrument, or I can interchange them as I need them.

Using a series of disposable tips enables me to work without the composite sticking. This has reduced the necessity for meticulous management of expensive instruments which frequently need replacement. And, I resist the desire to use dentin adhesive or an unfilled resin on the instrument to reduce sticking.