Ch. 9- Dental Ceramics

Indirect restoration- made outside the mouth

Crowns

  • used to restore teeth when a substantial amt of tooth structure is missing; encircle and support tooth structure.

  • cemented into place

  • difference in picture:

    • one is more radiopaque- has metal

    • other is full ceramic- no underlying metal

Bridges

  • replaces area where tooth is missing

  • ex. missing 30- wanted option to fill space

  • 2 teeth adjacent to missing area, the tooth structure has to be ground down to allow bridge to be seated- called Abutment teeth

  • pontic- part that is filling the missing space

  • Radiograph ex.

Inlay

  • made outside of mouth, but is made to fit inside tooth idk what she said oops

  • indirect, made in lab

Onlay

  • includes at least one cusp

  • indirect?

  • fits the specific shape of the preparation

Dental ceramics

  • introduced with limited success > 100 yrs ago

  • early ceramics were brittle and weak

  • Modern ceramics

    • Much stronger than original porcelains

    • used in crown, inlays, onlays, and veneers

    • can be bonded to metals and tooth structures

Ceramics/porcelain

  • ceramics- describes porcelain as well as a variety

  • the umbrella term that porcelain falls under

  • 2 types of ceramics

    • Glass based-

      • silica is main component

      • Glassy matrix

      • include porcelains and reinforced glass-based ceramics

    • Non-glass based

      • composed of simple or complex oxides

      • no glassy matric

      • include alumina and zirconia

    • Advantages of cermaic restorations

    • -no

    • bio

    • wear

    • stain

    • ability

    • excellent

    • Brittleness

    • Wear

    • Difficulty

    • The

    • Difficulty of polishing them in the mouth

Glass-based ceramics

  • Porcelain

    • Term used in dent for years to describe the class of tooth-colored dental materials

      • composed of feldspar

      • silica

      • quartz

      • kaolin

      • glass

    • Materials that are high in glass content are VERY esthetic, but is very brittle and is prone to fracture

  • Kaolin

    • soft white clay

  • Feldspar

    • earths crust

  • Feldspathic Porcelain

    • until

    • porcelain

    • metal

    • feldspathic

  • Alumina porcelain

    • made in 1965

    • Glassy type of porcelain that is hald aluminum oxide in a melted glass silica matrix

  • Reinforced Glass-based ceramics

    • stronger glass material

    • more than tripled frscture resis than original

  • Litium Discilicate

    • very esthetic-mimics natural teeth

    • popular for veneers

Non-glass based ceramics

  • Alumina

    • alternative to Porcelain fused metal crown

    • high flexural strength about 3x original based materials

  • Zirconia

    • Strongest ceramic materials currently used in dentistry

    • highest flexural strength and fracture toughness

    • not very esthetic

Ceramic properties

  • Physical and Mechanical properties

    • newer ceramic

    • non

    • zirconia

  • Thermal properties

    • Ceramic

    • They will

  • Optical properties

    • Translucency

      • Allow

      • Glass

      • Light can pass through surface and into body material and some can bounce out?

    • Reflectance

      • Surface that may reflect light

      • How

    • Opacity

      • Opaque

      • Non-glass

        • Least esthetic

    • Vitality

      • Glass

      • They

      • They

  • Biocompatibility

    • Ceramic

    • Studies have not shown an adverse tissue response

  • Fabrication of all ceramic restorations

    • Slip

    • Heat

    • sinter

    • computer

  • Slip-casting

    • Ceramic

    • slip

    • this core is then infiltrated

  • Heat-pressing

    • aka

    • ceramic

    • high temps and pressure are used

  • Sintering

    • Ceramic

    • process

    • feldspathic

  • Computer-aided machining

    • Various

    • An optical impression

  • CAD/CAM Technology

    • A computer

    • A block

    • A computer

  • In 1986 the CEREC system was the first to be introduced to dentistry

    • Allows for manufacture

      • Take

      • Computer

      • Crown

      • Delivered

  • Resin hybrid ceramics

    • Hybrid

    • combine

    • easy

    • tough

    • relatively new

  • Clinical applications for ceramic materials

    • Newer

    • People

    • Some

    • Pts

    • When

    • Dental Hygienist may be called on to inform pt abt pros and cons of various dental materials

  • Rationale for selection of ceramic materials

    • Porcelain

      • Used

        • Prone

      • Used

      • Risk

      • Leucite-Reinforced Ceramics

        • Work

        • Not strong enough to hold up as posterior crowns

      • Lithium Disilicate

        • Has

        • Can

    • Alumina and Zirconia

      • Very

      • Opaque

      • Alumina

      • Zirconia is suitable alternative for PFM crowns-good for bruxers

    • Porcelain Veneers

      • Thin

      • Used

      • Bonded

      • Directly

      • Indirectly

        • Also

        • More

    • Porcelain-metal restorations

      • Combining porcelain

      • metal internal core with an esthetic covering

      • Low fusing

      • metal

      • porcelain

        • durable bond is formed

      • Created in layers

      • First

      • Subsequent

      • Incisal

      • Porcelain

    • Porcelain metal failures

      • Most

      • The

      • The bond at the metal oxide layer may be inadequate and cause porcelain failure

      • Coefficient of thermal expansion of porcelain and the metal need to be compatible to avoid fracture

    • Glazing

      • The

      • Glazing

      • Porcelain

    • Finishing and Polishing Ceramics

      • Heavy

      • Low

      • Generation

    • Maintenance of ALl-ceramic restorations

      • Care

      • Do not

      • Select

      • USS

      • Occlusal

        • restorations