My 15-Year Journey With Lithium Disilicate
Tony Hatch, D.D.S.
Sponsored by Ivoclar
Our journey as dentists is one of lifelong learning as we continue our mission to improve our patient's quality of life and restore the natural function and esthetics of their smiles. It is an evolutionary journey to uncover the technologies and materials that work best in our hands and afford us reliability, efficiency and restorative peace of mind that we are providing our patients with the best care the profession has to offer.
As a CEREC® dentist, I have kept pace with the rapid technological advancements in the machinery and software as well as in the latest material developments in order to expand the versatility of restorative indications and treatments now possible for in-office dental care as well as improve the life-like esthetics and restorative efficiency and durability that patients expect and demand. For the past 15 years I have used and prescribed the IPS e.max family of millable materials to restore my patients in-house and in the laboratory. From single monolithic crowns, 3-unit bridges and custom implant abutments to combination and full mouth cases, the IPS e.max family of materials have evolved along with the technology to cover all these indications and more to ensure seamless esthetics, predictability and reliability in restorative dentistry.
In this article, I want to share five cases that illustrate my personal journey of professional growth over the years and best demonstrate the versatility that advancements in technology and millable materials have brought to the dental practice.
Strength and Durability
Bob was my very first case using IPS e.max CAD and is an example of the durability and strength of the material. Bob was a lifelong bruxer, a parafunctional habit that had resulted in the loss of teeth in the posterior and compensatory eruption of his mandibular anterior teeth (Figure 1). I knew that to reestablish vertical dimension of occlusion (VDO) and alignment of the upper and lower teeth, I would need to open his VDO by placing crowns on teeth #21-#28 (Figure 2 and 3).
However, in 2007 the range of esthetic all-ceramic materials available for the milling of chairside restorations was limited and most did not possess the flexural strength that would withstand the forces of bruxing. The exception was IPS e.max CAD lithium disilicate, a high strength lithium disilicate all-ceramic with a flexural strength of 360-400 MPa. The milled IPS e.max CAD crowns placed on teeth #21-#28 balanced his occlusion (Figure 4) and are still in full function today…14+ years later.
Cindy presented to my practice needing a crown to restore the recently placed implant on maxillary tooth #11 (Figure 5). Both the angulation of the implant and the location of the site in the esthetic zone necessitated use of a custom abutment and non-screw-retained crown to achieve the proper emergence profile and esthetics the case demanded (Figure 6). Prior to 2014, restoring an implant site with a custom abutment necessitated outsourcing the design and milling of the abutment to a dental laboratory, which is costly, or using a prefabricated abutment, which most always lacked the proper support, emergence profile, and contour required for an esthetic outcome. When Ivoclar Vivadent, in conjunction with Sirona Dental Systems, developed the IPS e.max CAD Abutment Solution in 2015, the system enabled clinicians like me to design mill, and place abutments (Figures 7 and 8) and corresponding restorations in the practice (Figures 9 and 10).
Tried and True
With attention laser focused on the dental implant as the gold standard for replacing lost dentition, the time-tested three-unit bridge is often forgotten and even considered substandard by many clinicians as a valid restorative solution. However, there are still a large number of cases where the 3-unit bridge is a better solution whether the primary concern is cost, extent of osseous surgery or in some cases a better esthetic solution.
A case in point was a patient who presented to my practice with a 17-year-old, 3-unit PFM bridge on teeth #11-#13 (Figures 11 and 12). Although an implant for tooth #12 and crowns on teeth #11 and #13 was suggested to the patient, she immediately declined, expressing a desire for a quicker option that did not require surgery. Fortunately, IPS e.max CAD #32 block provided me with a solution that would meet her demands. I was able to prep and provisionalize her teeth on a Tuesday and deliver and seat the final highly esthetic milled bridge two days later (Figures 13 and 14). She left the practice a very happy and satisfied patient.
Figures 11 & 12: The patient presented to the practice with a 17-year-old PFM 3-unit bridge. An implant solution was presented to the patient but was rejected. She wanted a quick solution that did not involve surgery.
A Unique Solution
A number of teenagers with congenitally missing laterals who are undergoing orthodontic treatment have presented to the practice wearing Hawley retainers with a debonded denture tooth meant to bridge the gap until an implant can be placed which in some cases could be 5+ years. I began offering these patients a bonded IPS e.max CAD single wing Maryland bridge to replace the missing lateral. The solution requires no anesthesia, no temporaries, and can typically be milled from an IPS e.max CAD #14 block in the same amount of time as a single crown. This long-term solution has become so popular in my area that other local dentists are now referring their young patients to me for treatment.
Tina’s case is a perfect example of how a chairside solution can be easily and quickly provided for our young patients. Tina presented to the practice congenitally missing lateral #10 (Figure 15). She was adamant she did not want, “a retainer with teeth on it”. In a short, two-and-a-half hours I was able to mill a cantilever bridge for #10-#11 (Figure 16) and have her back to the orthodontist for a final retainer impression (Figures 17 and 18).
Full Mouth Reconstruction
When faced with a complex full mouth cosmetic reconstruction case, it is reassuring to work with a material that spans all indications from veneers to implant crowns and that takes the guesswork out of matching different types of materials from zirconia to all-ceramic. The wide range on indications covered by the IPS e.max family of materials allows an abutment crown next to a veneer, which is next to a three-quarter crown with the knowledge that all restorations will seamlessly match in shade and esthetics.
Tim presented to the practice while still undergoing orthodontic treatment (Figure 19). His goal at the end of orthodontic and restorative treatment was to achieve a broad esthetic smile. He was missing his two maxillary lateral incisors and lower premolars, which would be restored with implant crowns (Figure 20). His smile makeover included seven full contour crowns, four implant crowns, and 12 veneers all fabricated in the laboratory using the IPS e.max family of materials (Figures 21-22). His goal was achieved using only a single restorative material
Figures 21-22: In all, seven full contour crowns, four implant crowns (two of which were screw-retained and two with custom abutments) along with 12 veneers restored the patient’s smile. All 22 restorations were fabricated from the IPS e.max family of materials. Working within a family of restorative materials that covers all indications takes the esthetic guesswork out of full-mouth reconstruction cases.