Posts Under Cerec
Following a sports injury, this patient was left without a lower central incisor. Initially, the patient was using a removable prosthetic (partial denture) to replce this missing tooth. After wearing the appliance for a few years, the patient decided a fixed option was in order.
An implant fixture was placed with excellent inital stability. A temporary crown was fabricated so the patient no longer required the use of the denture. Once integration of the implant was complete, the patient was ready for the final prosthetic.
A scanpost was placed atop the implant fixture and a Cerec digital image was obtained. The Cerec software was used to create an Emax custom abutment as well as an Emax custom crown.
In the above images, the custom abutment has been delivered and torqued to 35Ncm. The access hole has been sealed with teflon.
The final crown was cemented and minor tissue recontouring completed with a Waterlase to sculpt the tissues into an esthetic emergence profile. With some additional restorative work (i.e. repair of the fractured canine and a full coverage crown for the adjacet central), the esthetics of this case would be complete.
What happens to a tooth once it has a cavity and subsequent restoration to repair this defect?
The life cycle of a tooth that has received a restoration is very predictable and has been well documented over the years.
The first area of decay for a tooth is usually the biting surface or proximal surface (i.e. between adjacent teeth). The initial restoration is small and usually free of sensitivity. As time goes by, the filling and surrounding tooth wear (from abrasion, acid erosion, thermal flexure, etc) and the filling fails. Moisture begins to penetrate the margins and recurrent decay develops. Most often, the restoration is not replaced in a timely manner because there are no symptoms with this process and the patient does not feel the treatment is necessary.
Once the patient decides they are ready for treatment, the old restoration is removed and a larger one placed to accomodate the damaged areas of the tooth. This means the width has increased, the depth has increased, the risk of sensitivity has increased (and the proximal surfaces are usually involved).
As the size of the resoration increases, so does the risk of fracture. Once recurrent decay develops around a filling of this stage, a fracture is inevitable. The fracture usually encompasses a large portion of the tooth and may encroach on the pulp tissue (nerve supply) of the tooth.
Further recurrent decay will develop with time and, when left untreated, will lead to even further fracture and risk for root canal therapy. As this point the only restorative option for the tooth will be a crown.
No restoration is permanent. Eventually the crown will require replacement. If the treatment has been delayed and even more tooth structure is lost, then the tooth may no longer be restorable and require extraction.
This doesn't sound very good, does it?! There are ways to prevent the progression from simple filling to extraction. The single most important thing is routine hygiene maintenance to keep restoration margins free of long-standing plaque and calculus debris. Routine radiographic and visual assessment of the restorations is necessary to detect failing restorations. Timely replacement of restorations can dramatically reduce the increase in size from one restoration to the next.
Choosing the right filling material can also improve the life-span of a restored tooth. Once the filling size has progressed to greater than 1/2 the intercuspal width or a cusp requires replacement, then a CEREC onlay, 3/4 crown or crown are the most durable and long-lasting options. They will reduce the risk of fracture dramatically!
If a tooth gets to the stage where root canal therapy, periodontal surgery and a new crown are required, one has to consider the long-term prognosis for the tooth. In some cases the prognosis will be good. In others, the prognosis may be guarded at best. At this point, replacement of the tooth with an implant-supported crown may be the best option. Implant treatment most closely resembles the original tooth and has an excellent pronosis - if cared for, they may last a lifetime.
This patient presented for an emergency assessment of a fractured laterla incisor. The tooth had been previously endodontically treated (i.e. root canal) and had a large composite resin filling that encompassed all tooth surfaces. Due to the extent of these restorations, the tooth was in a highly compromised state and predisposed to fracture. (Sorry, the pre-operative photo did not save properly).
Luckily for this patient, there was enough tooth structure and healthy supporting tissues remaining to allow for a new restoration. The large amount of coronal tooth structure missing meant osseous crown lengthening was required achieve a stable crown margin that would not interfere with the biologic width (i.e. irritate the supporting tissues and bone causing chronic inflammation and premature failure of the restoration).
Crown lengthening was achieved using the Waterlase iPlus. The bone was moved apically 1-2mm as required and the soft tissues were recontoured. There was no need to delay placing the restoration 6-8 weeks as is normally required with traditional crown lengthening, because there is minimal risk of recession following this treatment with the Waterlase.
There is a video of this process at http://basinviewdental.com/dental-videos/
To increase retention, a Fiber Lux Parapost was placed into the root canal space of the tooth. This radiograph shows the post drill inserted into the canal as a reference to guage both the width and length of the canal space. The final post was placed 5mm from the root apex.
Once the post and resin core complex were completed, the final Cerec crown was fabricated using EMax (lithium disilicate) material. The crown was sintered in a ceramic furnace and stained to match the adjacent teeth. Two layers of glaze and polish were completed to stabilize this color.
Here is the post-operative view at two weeks following treatment.Other than minor healing still visible along the buccal margin, it is difficult to tell which tooth was restored. The disto-buccal tilt of the tooth is a product of the patient's occlusion and could not be corrected without significant alteration of the opposing lateral and canine teeth. The patient was happy to simply dupliacte the appearance of his tooth prior to the fracture. He is now going to return to have the same treatment completed for the upper left canine which currently has a large composite filling, 4 stainless steel pins and has been endodontically treated. The patient has chosen to proactively restore this tooth before it fractues
Thanks to the Cerec chairside system, the Waterlase iPlus and our Programat CS sintering furnace, this treatment was completed for this patient in a single appointment. No temporary crowns were required and there was no post-operative healing period following the minor crown lengthening. With traditional methods of treatment, this case would have taken months to complete. Crown lengthening would require 4-6 weeks of healing at a minimum while the patient wore a temporary crown. Once healing was complete, the temporary would be removed and a final impression fabricated to be sent to a dental laboratory. The temporary would be replaced and the patient would return in another 2 weeks for crown try-in. If the esthetics or fit were not acceptable, the crown would be sent back to the laboratory for adjustments while the patient wore the temporary for an additional week. In total, this could have taken 9+ weeks to complete!
At Basinview Dental Centre, Dr. Luke Haslam was able to complete this case in 2 hours! With these technolgies, we will not only see a reduction in treatment time, but also a reduction in treatment cost. In this case, the patient did not require referral to a periodontist to have the crown lengthening completed (as would be traditionally required). There was no commercial laboratory used to fabricate the restoration so there was no third party bill to pay. The patient was resposible for the treatment time and materials only which saved this patient close to $1000.00.
To learn more about our technology, please feel free to schedule a consultation with Dr, Luke Haslam at Basinview Dental Centre.
Case 1:Vita Enamic, 2M2T shade
The patient presented with large pinned amaglam restoration on tooth 46 with failing margins and recurrent decay. A full coverage restoration was recommended and the patient decided to proceed with a Cerec crown restoration.
The decay was excavated from the tooth and the remaining tooth structure was prepared for the Cerec crown. Hemostasis was achieved in subgingival areas using the Waterlase iPlus.
An Enamic 2M2T block by Vita was chosen for this restoration - a very durable and resilient material. The Enamic is a hybrid ceramic material with a composite resin matrix designed to resist the propagation of cracks thus reducing the risk of fracture. The material is quickly milled by the Cerec MCXL milling unit (this particular case took only 4min) and is easily adjusted with finishing burs. A slight increase in proximal contact strength during the design phase was required to achieve the desired intraoral contact strength. The Enamic polished well using a series of soft points, goats hair brushes and a cotton wheel with high shine paste (the polishing time was 10-15min). The crown was bonded using Scotchbond Universal and Rely-X Ultimate (3M ESPE).
The monochromatic nature of the Enamic block creates a very opaque looking crown. To improve esthetics, a lighter shade in combination with intraoral, resin-based stains should be used.
Case 2: Ivoclar Empress A3 MultiCAD
The loose gold onlay was easily removed, the decay excavated and the remaining tooth structure prepared for a full coverage restoration. Shade A3 Empress MultiCAD by Ivoclar was used to match the unrestored first bicuspid and canine. The Empress CAD blocks are a leucite reinforced glass ceramic - the multiCAD blocks have an internal shade gradient with increasing translucency that creates a tough, highly esthetic crown (milling time was 6.5 min with the Cerec MCXL).
The crown was bonded using Scotchbond Universal and Rely-X Ultimate (3M ESPE). The Ceraglaze ceramic polishing system was used create a high shine (approximately 10 minutes). The esthetics of the Empress block is lost in the post operative images due to the overshadowing nature of the surrounding gold onlays. The true nature of this case will be visible following replacement of the failing 35 onlay.
Dr. Luke Haslam is proud to offer a new restorative material at Basinview Dental Centre, the IPS Emax ceramic!
Emax is a lithium disilicate ceramic used for in-office Cerec restorations. It comes in a partially crystallized state which gives the block a blue hue, which is commonly referred to as the "blue state" or "blue block". The partial crystallization allows the block to be milled quickly and easily into a restoration in the Cerec milling chamber (e.g. crowns, inlays, onlays and veneers). Once milling is complete and the fit if the restoration verified, the ceramic is then "fired" in a furnace (Programmat CS by Ivoclar) for about 22 minutes. This completes the crystallization of the restoration giving it incredible strength and brings out the highly esthetic color. These restorations can also have characterizations added to them in the form of stains and glazes to give them an extremely natural look.
Due to the high strength and durability, these restorations are designed to be a long term restorative choice. Restorations of this type have a limited 20 year guarantee!
Ask Dr. Haslam if Emax is right for your restorative needs.
Cerec is the most advanced and widely used CAD/CAM system in dentistry. The software and hardware advances to this system have revolutionized the process of creating ceramic restorations. The release of the Cerec 4.0 software and the upgrade of the camera to the Bluecam were much anticipated changes. The ease of fabrication was dramatically increased following these updates. Now, Sirona (the manufacturere of Cerec) has done one better and created the new OminCAM. Rather than taking indiviual photos which are then stitched together by the software (as was the case with all previous camera systems), the new OmniCAM produces a seamless, colored, digital model by way of streaming video. The video acquisition requires no optical powder to produce contrast, thus making the process faster and easier!