“Hollywood” smile rehabilitations, smile enhancements, dental cosmetic enhancements, dental esthetic restorations matching existing teeth and restorations are all part of mainstream dentistry. These are all accomplished primarily by using crowns, veneers, inlays and onlays for natural teeth and the use of crowns, bridges and abutments for implant restored “teeth”. The primary materials used to achieve beautiful esthetic dental results are porcelain and zirconium. There are multiple different proprietary porcelain and zirconium systems available for dentists and dental lab technicians to utilize.
ALL dental porcelain’s have one thing in common: They CAN and DO break. This is a risk even when the dentist and the lab technician utilize the best materials and techniques, follow “the tried and true” procedures and execute their design and fabrication steps “to the letter” to maximize fit, form, esthetics, function and durability. All dental zirconium has one thing in common: getting a bacterial resistant seal of the underlying tooth is technique sensitive making it imperative that the zirconium prosthetic fabricator follow preferred dental adapted engineering milling protocols in detail for both sintered (heat treated) and non-sintered zirconium.
The things that most commonly cause porcelain dental restorations to fail (break/chip/crack; zirconium restorations to a much less degree) are:
- Hard crunchy foods (nuts, raw carrots, peanut brittle, pretzels, some apples, granola, etc)
- Fruits with small seeds that can get leveraged in biting surface grooves
- Physical trauma to the teeth directly
- Physical trauma that indirectly causes the teeth to hit together
- Chewing on ice
- Chewing on non-food items (pens, pipe’s, “cutting” fishing wire, opening things with your teeth, “cutting” thread)
Simplifying metallurgy and ceramic engineering for our purposes, zirconium is a transitional metal with ceramic like esthetics. Zirconium is harder and more durable than porcelain and as such is much more durable than porcelain when used to make a prosthetic inlay, onlay, crown or bridge. However zirconium, being harder, is more technique sensitive and requires elevated attention to detail to achieve ideally fitting prosthetics that will protect the underlying supporting tooth from bacterial decay. Premium dental porcelain systems have optics that can provide for a more natural looking restoration than current zirconium systems when/where esthetics are highly valued and fracture risk is accepted.
The widespread common use of these materials in dentistry tends to lull dentists and their lab technicians into under-engineering the use of porcelain and into utilizing cheaper, lower precision milling systems (labs) for their zirconium prosthetics.
This same widespread common use of porcelain and zirconium in dentistry also tends to lull both the patients and dentists into thinking that long-term performance is assumed. Although, modern material systems and application techniques do perform well with reasonable durability, when you are the patient whose esthetic/cosmetic porcelain prosthesis breaks or zirconium prosthetic develops pre-mature marginal decay, then it is of little comfort to know that you are in the minority. In an effort to clearly establish realistic expectations and financial responsibility for failed esthetic dental prosthesis (crowns, bridges, onlays, inlays, veneers, etc.).
As a result of porcelain’s low shear strength being an intrinsic unalterable risk associated with porcelain’s physical properties and limitations, we want to be sure that every patient:
- understands that any porcelain dental prosthesis can chip, crack, fracture, or break, and sometimes do!
As a result of zirconium’s hardness and newness to widespread dental use, we want to be sure that every patient:
- understands that while it is rare, a zirconium restoration can structurally fail due to fracture.
- understands that zirconium dental adhesion technology is not as well understood as that of porcelain and as such may or may not have an elevated risk of micro leakage and decay of supporting natural tooth structure.
- understands that the zirconium/titanium interface created when restoring dental implants with zirconium abutments is not as well studied as the metal and porcelain systems traditionally used to restore dental implants.
We want to minimize misunderstandings and make sure that every patient knows and accepts that:
- since dentistry’s technology and science cannot guarantee any porcelain or zirconium prosthesis against fracture failure, esthetic failure, decay failure, structural failure or any form of durability/longevity insufficiencies; neither do we. We can only use the finest materials available, employ the most reliable techniques, be thorough and detailed so as to provide our patients with the best statistical results.
- if a porcelain or zirconium restoration needs to be re-treated due to failure &/or patient preference, any and all re-treatment(s) will be at our normal full fee and will be the total responsibility of the patient. The dental reality is that sometimes it costs us more to re-treat a failed restoration than it does to provide the initial prosthetic restoration.