What are Fixed Partial Dentures?
Fixed partial dentures are prostheses affixed to replace natural teeth permanently and cannot be removed for routine cleaning processes. Support is provided by the adjacent natural teeth. The prostheses are screwed and mechanically fastened to the tooth roots or abutments of the tooth. More importantly, alignment of teeth, chewing and speaking functionalities is restored with bridges or FPDs. The bridges provide support to the cheeks and lips and fill the gaps in the teeth and restore performance.
The procedure for attaching FPDs may take several visits. In the first visit, a portion of the dentin and enamel of the teeth on either side of the gap are removed. Impressions of the teeth are taken and sent to a laboratory to fabricate the bridge with the correct bite calculations to match existing natural teeth. The fixed partial bridges are cemented in the space of the missing tooth along with a pontic. The crowns are then cemented over it to provide support to the bridge.
Types of FPDs
Zirconia based FPDs: Posterior teeth carry heavy chewing loads for which Zirconia core ceramic dentures are a more probable option. Fully sintered (or partially) zirconium oxide can be used to prepare copings and frameworks with the usage of CAD/CAM technology. Zirconia-based dentures are highly fracture-resistant and can withstand excessive occlusal loads. Latest innovations in the FPD realm are the Yttrium tetragonal zirconia polycrystal or the Y-TZP which are high-strength systems. The biocompatibility and superior quality of the Y-TZP and advanced cementing mechanisms make it a popular choice in dental restorations.
3M ESPE Lava ® Restorations: Developed by Lava ® Precisions Solutions, the 3M ESPE material is integrated with digital technology to prepare a specially-formulated zirconia that is designed to provide high strength restorations. The technology enables the preparation of single crowns, splinted crowns, unit bridges and 4-5-6-unit bridges, cantilever bridges, inlay and onlay bridges, anterior Maryland bridges and telescopes.
Zenostar ® Dental concepts: Zenostar ® is a new concept in monolithic restorations that are single-piece, full-contour and does not consist of a ceramic veneer. Besides a no-chip technology, it is non-metallic, cost-effective, and milled to provide high-technology dental reconstruction. Especially suited to fill limited occlusal spaces, Zenostar ® is biocompatible, durable and clear.
Types of Crowns
All ceramic crowns: All ceramic crowns are metal-free and contain no material other than ceramic. Zirconia and EMAX are two types of all-ceramic crowns that can be produced with the CAD/CAM 3D technology. There are several advantages to the all-ceramic crown. They are ideal for people with less space within the mouth. All ceramic crowns give a natural appearance to the teeth. Since they are made from thin material, they are light weight and integrate into the gum tissue allowing the tissue to grow alongside the crown. Allergic reactions and sensitivity to heat and cold are eliminated with the all-ceramic crown. To place the crown, the teeth are first cleaned, reshaped and tapered to fit the crown. Dental putty is used to take an impression and fabricate the crown. A temporary fitting is set till the new crown is prepared. Once the crown is ready, the surface of the tooth is roughed with etching acid to enable the crown to adhere to the tooth.
Porcelain fused metal crowns: PFMs or porcelain fused metal crowns are full-cast crowns that can be fused to most parts of the tooth. They are a combination of porcelain and metal crowns. Metal alloys are melted at high temperatures to adhere the porcelain to the surface. With this procedure the porcelain bonds to the tooth and does not change colour. A large part of the tooth tissue is removed to make space for the porcelain and metal. PFMs display high long-term success rates. They are strong, stable and have great aesthetic appeal. PFMs are most preferred due to their natural look.
PFMs vs. all-ceramic crowns
One of the basic advantages of the PFM over the all-ceramic is that of appearance and aesthetics. PFMs offer greater strength, durability, and stability making them long lasting. The metal underneath the porcelain keeps the crown characteristically intact for adequate reinforcement of the tooth. They fit precisely and are clinically of no concern. On the other hand, it just might seem that the wearer has opposing teeth. Whereas in an all-ceramic crown, the results achieved are of natural looking teeth.
The choice between PFM and all-ceramic is not an impasse. All-ceramics are best used when the area of restoration is in a prominent position where appearance is critical. Posterior teeth require added strength and therefore best resolved with PFMs.
PFMs have their own drawbacks. The metal in the PFM can cause gingival allergy, irritation and colour changes in the area of implant. This irritability can cause gingival tissue shrinkage. Scanning the PFM area does not provide adequate clarity in the image. Besides PFMs can pose a challenge for a really natural look in which case all-ceramic crowns provide the best aesthetics compared to PFMs.
Dental Solutions, Bangalore provide cost-effective and patient-oriented resolutions for dentures and crowns placements.