Porcelain has been one of the key materials that the clinician has relied on for nearly fifty years. Porcelain fused to metal is still a popular choice today. With the dramatic increase in the aging baby boomer market metal free restoration has rapidly evolved as one of the primary restorative materials of 21st century.
Leucite containing glass ceramics (porcelains) have been used now for over forty years in porcelain fused to metal restorations (PFM). Conventional PFM porcelains are usually fired at temperatures higher than 900C. The problem with these types of porcelains is they contain high percent of leucite (35-55%), which was used to modify thermal expansion properties. This high percent of leucite crystals have been associated with a tendency of wearing the opposing dentition.1
Material scientist and laboratory technicians then developed low-fusing low or no leucite porcelains in the mid 1990s. They were developed in response to the concerns about wear upon the opposing dentition.
Finesse All-Ceramic was designed to be a low fusing porcelain with a relatively low level (5-7%) crystalline leucite content. The low levels of leucite ensure that intraoral wear was significantly reduced as validated in-vitro studies and clinical observation.2 In a study done by Elmaria in 2002 the wear of Finesse was less than the leading pressed ceramic and the wear was statistically equivalent to cast gold.3
The Finesse All-ceramic also proved to be highly polishable and with a low fusion temperature of 700-800C ensures that thermal mismatch stresses are minimized. The coefficient of thermal expansion of the core material is matched to the Finesse veneering material.
Finesse All-ceramic ‘pressing’ procedure consist of ingots that are injection molded into a lost-wax cavity under medium pressure which reduces the porosity and flaws common in hand-built porcelain veneering layers (Fig. 1). Consequently, these materials are significantly stronger than traditional dental porcelains.4
It is possible to press a coping of this material and veneer it in a manner similar to a PFM coping. This is currently not feasible with many other all-ceramic systems including industry standard in pressed ceramics.5
Finesse All-Ceramic has a low leucite veneering porcelain to ensure significantly reduced wear against the opposing dentition.
Laboratory Technician Perspective
Michael Milne is the technical director for the laboratory programs at the Las Vegas Institute. He created this case and has worked with Finesse All- Ceramic extensively for the last year.
“With today’s technology and the advancements made in materials, many options are available to the laboratories in fabricating a beautiful restorative case. With this patient, Finesse All -Ceramic Pressable Ceramics was used. The ingot chosen was FOP 40 (Finesse Opaque 40%). When pressing thinner than 1mm, I like the stability of Finesse.”
“The anterior veneers were then cut back and intrinsic stains placed to highlight incisal edge mamalons (Fig. 2). The patient desired a bleach shade 030 cervical to 010 incisal. To insure a high value translucency on the incisal edge, mixtures of Finesse porcelain opal light and opal white were used on the marginal ridges and opal light used to fill in other areas.”
CLINICAL CASE
A 36-year-old female’s chief complaint was the appearance of her upper and lower anterior teeth. There was a considerable amount of discoloration of her teeth. As well the rotation and crowding was also a concern. She was aware that her midline was off by about 2mm and was interested in correcting this as well (Figs. 3-9).
A wax-up of the shape and length of the teeth she desired was done before her appointment. A putty matrix of the wax-up was fabricated to assist the clinician with their provisionals and a preparation matrix was made to assist the clinician preparing the teeth (Figs. 10-12).
The gingival tissue was contoured around her upper left cuspid and central incisor. The teeth were prepared approximately with .06mm facial reduction and the margin extended over the incisal edge to approximately 1mm (Figs. 13 & 14). Eight teeth were prepared from first premolar to first premolar. A preparation matrix derived from the wax-up was placed in the mouth to verify adequate reduction (Fig. 15). A polyvinyl impression was then taken of the upper teeth. The teeth were cleaned and air dried with chlorhexidine and then a coat of Glumma Densensitizer (Heraeus Kulzer, Armonk, NY) was placed on the teeth as well and air-dried. The putty matrix of the wax-up was injected with Integrity Bleach Shade (Dentsply Caulk, Milford DE) and placed in the mouth for approximately 2 minutes (Fig. 16). The provisionals are meant to stay on the teeth by mechanical retention. A 7901 fluted carbide bur is used to trim the excess acrylic from the margins. Various polishing cups are used to enhance the provisionals (Fig. 17).
The lower teeth were then prepared in the same manner. The provisionals we created with a matrix as well.
When the patient returned she was anesthetized and the provisionals were cut off. The fit and shape of the veneers were verified on the working models as well as intraorally.
A rubber dam was placed to insure isolation for cementation. The try-in paste was rinsed from the veneers and phosphoric acid was placed in each veneer for 30 seconds to acidify the internal surface. Kerr’s Silane Primer (SDS Kerr, Orange, CA) was placed on each veneer and allowed to air dry for one minute.
The teeth were scrubbed with chlorhexidine for 15 seconds and rinsed. The teeth were then etched two at a time with 37% phosphoric acid and rinsed. A single component adhesive system was placed on the teeth and the solvent was evaporated off. The adhesive was light cured. The base portion of the luting cement was placed on the two central incisors. The excess luting cement is cleaned off and each veneer is tacked at the apex of the tooth for five seconds. The three veneers on the right were tacked to place.
The last three veneers on her left side were then tacked to place. Each veneer was carefully flossed and all the veneers were completely cured to place. The excess luting cement is then cleaned off with a scaler. The occlusion is checked and the restorations are polished with various polishing cups (Figs. 18-23).
The lower veneers we then tried in and the fit and shade was verified. The veneers were then prepared for cementation like the upper veneers. The lower veneers were then cemented to place in the same manner as the upper veneers.
There have been dramatic improvements in porcelain development over the last 40 years. Finesse All-Ceramic porcelain restorations has taken a good product and refined it to achieve the ultimate in wear, strength, and beauty. Finesse All-Ceramic can give practitioners an integral solution to their restorative needs.
Dr. Poss is Clinical Instructor for various programs at the Las Vegas Institute for Advanced Dental Studies. He maitains an esthetic and restorative practice in Brentwood, TN.
Oral Health welcomes this original article.
REFERENCES
1.Imai Y, Suzuki S, Fukushima S., 2000, Enamel wear of modified porcelains, Am J Dent., Dec; 13(6): 315-23.
2.Gonzaga CC, Okada CY, Santos AL, Goulart EP 2002, Microstructure of Dental Porcelains, J Dent. Res., v81 (4), No. 1857.
3.Elmaria A., Goldstein GR, Vijayaraghavan TV, and Legeros R, 2002, Evaluation of Enamel Wear Caused by Ceramic Materials and Gold, Dent. J. Res., v81(4), No.3242.
4.Beham G, 1990, IPS Empress: A New Ceramic Technology, Ivoclar-Vivadent Report 6, 3, Ivoclar AG, Schaan, Furstentum Liechtenstein.
5.Berland LF, 1999, Building a better cosmetic practice, Dent Today, Jun;18(6):56-8, 60-1.
