Longevity of
Porcelain Veneers
One of the most common questions from patients who are interested in porcelain veneers is this one:
"How long will they stay?"
While this patient would definitely benefit from
the science and art of cosmetic dentistry, her main concern was how
long she would enjoy
her new smile.
The survival rate of porcelain veneers has been reported in numerous scientific publications.
The most important prerequisite to a "permanent"
outcome of porcelain veneers is meticulous attention to and the proper execution of the porcelain-to-tooth bonding process.
Your dentist needs to fully understand the chemistry behind bonding agents and has to know how to exactly apply these
materials without compromising the full potential quality of a bonding agent. The questions that should be asked are:
1. What is in the bottle? See here.
2. What does every step of the bonding procedure do?
3. How can the optimum result be achieved?
4. How strong is strong enough?
5. What exactly determines the longevity of a porcelain restoration?
6. What product is my dentist using, and WHY?
7. What is a "hybrid layer?" See here.
8. What is the "wet-field" technique?
9. What are the possible consequences of an inept use of bonding materials?
While many companies have tried to reinvent the wheel by "developing" next-generation bonding agents that require less steps, there are no real
short cuts when it comes to dental bonding. The additional seconds that are spent on each separate step for the conditioning of the tooth and the
intaglio surface of the porcelain veneer are seconds well spent.
Each step should be well understood. What is the etching gel doing to the tooth surface and the intaglio surface of the porcelain? What does the
silane agent do to the porcelain? Ask your dentist or ask Dr. Rabanus.
The optimum result and best bonding strength is achieved by following the product's instructions carefully while using complete isolation of the
treated teeth from the oral environment with rubberdam. This will avoid contamination with bacteria and saliva and will keep the area as dry as needed.
A wet field necessary to establish an optimum hybrid layer with certain bonding primers
should be established in a very controlled fashion with an air-water syringe, not saliva.
The possible consequences of an inept use of bonding materials by the dentist are:
1. Non-hybridized collagen fibers with a Modulus of Elasticity of 0.3 GPa.
2. Nano-leakage.
3. Trapped water droplets.
4. Fluid shifts with dentinal sensitivity.
5. Peripheral leakage leading to pulpal irritation due to bacterial invasion.
6. Over-etching with deterioration of the bond over time.
8. Polymerization effects, such as tearing open of different components of the bonding complex.
9. Thermal changes can create and contribute to the disintegration of the ill-developed bonding complex.
10. Bonding complex will not withstand occlusal stress.
11. Only 10% resin reached the collapsed collagen layer of the bonding complex.
Please relate the numbers of this list to the numbers in the image below.
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Most studies have reported survival rates of bonded porcelain veneers of far more than 90% after five to ten years of usage.
Meticulous attention and proper execution of
the bonding process will allow these porcelain veneers to survive for
many years.
One study reported that all veneers evaluated after 48 months were still clinically acceptable
(The Clinical Longevity of Porcelain Veneers. A 48-month clinical evaluation. Kihn PW et al., JADA, Vol. 129, 1998).
Independent studies have demonstrated that the survival rate of porcelain veneers is tightly correlated to the skill and experience
of the operator. Using the same bonding agents, skilled and experienced operators attained a much higher survival rate (closer to
100%) than unexperienced operators.
References:
Midterm results of a 5-year prospective clinical investigation of extended ceramic veneers.
Guess PC, Stappert CF. Dent Mater. 2008 Jun;24(6):804-13.
Porcelain laminate veneers. A retrospective evaluation after 1 to 10 years of service: Part II--Clinical results.
Dumfahrt H, Schaeffer H. Int J Prosthodont. 2000 Jan-Feb;13(1):9-18.
Five-year clinical performance of porcelain laminate veneers.
Aristidis GA, Dimitra B. Quintessence Int. 2002 Mar;33(3):185-9.
Influence of operator skill on microleakege of total-etch and self-etch bonding systems.
Giachetti L, Scaminaci Russo D, Bambi C, Nieri M, Bertini F. J Dent. 2008
Clinical performance of porcelain laminate veneers. A retrospective evaluation over a period of 6.5 years.
Shaini FJ, Shortall AC, Marquis PM. J Oral Rehabil. 1997 Aug;24(8):553-9.
Survival rates of all-ceramic systems differ by clinical indication and fabrication method.
Land MF, Hopp CD. J Evid Based Dent Pract. 2010;10(1):37-8.
Recent advances in materials for all-ceramic restorations.
Griggs JA. Dent Clin North Am. 2007;51(3):713-8.
Critical appraisal. Porcelain veneer outcomes. Part I.
Swift EJ Jr, Friedman MJ. J Esthet Restor Dent. 2006;18(1):54-7.
Longevity and failure load of ceramic veneers with different preparation designs after exposure to masticatory simulation.
Stappert CF, Ozden U, Gerds T, Strub JR. J Prosthet Dent. 2005:94(2):132-9.
Find additional information, go here.
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