Outcome 5 - Fixed Prosthodontics Flashcards
Define Fixed Prosthesis
The prosthesis is permanently cemented into place and cannot be removed by the patient
Indications for Dental Prosthesis
When there is not enough naturual tooth structure remaining to retiain a new restoration - more coverage with a dental prosthesis may be advised. This can also occur as a result of extensive decay or the loss of tooth structure through disease/trauma
How treatment plan for an indirect restoration is determined?
-Patient History
-full mouth radiographs/specific area radiographs
-intraoral examination
-diagnostic models
-diagnostic models mounted on an articulator
-face bow records
What are indirect restorations?
Unlike restorative restorations such as amalgam or composite, they are not placed directly into the mouth but are made indirectly outsode of the mouth then “fixed” or cemented into place in the mouth permanently
What can restorations be fabricated from?
Gold, precious metal alloys, porcelain, ceramic or combinations of both
What are Inlays?
Restorations resemble class II not involving dental cusps
What are Onlays?
Restoratios involving dental cusps
What are veneers?
Made from porcelain or other ceramic. They are fabricated by technicians in a dental lab and are bonded to the facial surface of prepared anterior teeth by the dental team. These veneers are very aesthetic as porcelain has a more natural appearance and reflects light in much the same way as enamel.
What is a Crown?
A Crown is an indirect restoration that covers all or almost all of the anatomic portion of the tooth.
What is a full crown?
Covers the entire anatomic portion of the tooth
What is a 3/4 Crown?
Usually leave sone surface intact. This surface is often the labial or facial surface with the Crown covering the lingual
What is a bridge?
A bridge is a fixed prosthetic replacement for one or two missing adjacent teeth where there are strong supporting teeth on each side of the gap. The replacement teeth are called pontic and are connected to full crowns on either side of the gap, called abutments.
What are Implant Assisted Crowns & Bridges?
Dental implant is used when natural tooth has been lost. Dental implant is an artificial anchor (post like) that is surgically placed into the bone. Dental implant act as the “root of the tooth” Dental crown or bridge is added to aid intra-oral function. Dental implants are used in fixed and removable prosthetics.(removable prosthetics s will be discussed next semester)
What are Computer Assisted Prosthetics?
Computer assisted restorations use an in-office ceramic restoration system. These systems are often referred to as CAD/CAM which means Computer Assisted Design or Manufacturing. Advantages of using these machines include: one visit procedure, no impressions required, no temporary restoration required, and no outside laboratory costs.
What is a CEREC machine?
uses computer imaging to custom fabricate a ceramic inlay, onlay or crown in the office, within approximately 90 minutes.
What is Core Buildup?
If the tooth is vital, the procedure to create crown length or support is called a core buildup. The core buildup is created in a procedure very similar to a restorative filling.
-Amalgam or Composite resin are often used as core buildup materials though there are reinforced glass ionomer materials specifically designed for core buildup situations
-Retentive pins may also be necessary to retain the core buildup. These must be placed before the core buildup into tooth structure and then incorporated into the buildup material.
- In either case, the core is placed and then reduced in the same way that natural tooth structure would be for the crown or abutment prep
What is a Post & Core?
If the tooth to be crowned had endodontic treatment and lacks support, a post may be placed into one of the filled canals and then a core built up around it. These can be pre-fabricated posts or cast post and cores fabricated by a dental laboratory.
A prefabricated post is cemented deep into one of the canals with a portion remaining out of the canal on which the core material is placed.
Any type of core buildup material can then be placed over the post, which is then reduced again in the same way that natural tooth structure would be for the crown or abutment preparation. A cast post and core is generally made as one unit in the lab. The material used can be metal, resin or ceramic.
What kind of Bonding Systems?
Dentin bonding systems can also be used to create micromechanical retention between the tooth structure and prosthesis.
- Can be self curing or dual cured and can use either a single application or may require the mixing of two materials
- This bonding is usually micro-mechanical in nature and occurs when the surface of the restoration has been microetched
- includes etching of the dentinal tubules, placing a bonding resin or agent and then applying the bonding material to secure the prosthesis
This procedure is the most common method of adhering veneers, but is also often used for ceramic crowns. It is the most complex and time consuming method.
What is Mechanical Tissue Displacement?
Tooth preparation for a fixed prosthetic extends to or slightly below the gingival margin of the tooth. The impression for laboratory fabrication of the prosthetic must extend into the sulcus for accurate replication of the margin. The free gingiva must be retracted and the sulcus widened to enable the impression material to flow around and beyond the margin of the tooth preparation.
Methods of Gingival Retraction?
Physical/Chemical Retraction
Surgical Retraction
What is the most common method of gingival retraction?
Through the placement of a retraction cord within the gingival sulcus
What is Physical / Chemical Gingival Retraction?
Placement of retraction cord within the gingival sulcus
-cord physically forces the gingival tissue away from the tooth, widening the sulcus
-the cord remains within the sulcus for a short period of time and is removed immediately prior to insertion of impression material
What are the Chemical Solutions used during Gingival cord retraction?
-often refered to as hemostatic solutions
-may include aluminum chloride, epinephrine, or ferric sulfate
- tissue management is achieved through the use of chemical agents introuduced to the tissue via the retraction cord to temporarily contract the tissue and act as a vasoconstriction which will control any bleeding that may have been initiated in preparing the tooth.
Other methods of physical gingival retraction?
Cordless retraction materials - provide retraction by injection of a paste like material infused with a hemostatic solution