Prosthodontics

  • Removable Denture

    Removable denture is a denture that can be taken out by patient. It is divided to partial and complete denture. Its aim is to replace missing teeth.

    Notes

    Initially it may be difficult to get use to a new denture, but you will soon be accustomed to it after wearing it for a period of time.

    A new denture may be uncomfortable to wear within the first 6 months. It is not unusual to require some adjustments on the new denture.

    Since oral conditions may change with time, a denture may gradually become loose and unfit. Therefore, an oral check-up should be done at least once a year so that the dentist can adjust the denture according to the oral condition.

  • Crown

    A crown refers to the placement of an artificial crown on a tooth. It acts as a 'cap' that fits over the tooth which has been previously shaped and contoured.

    Purpose

    • To restore the original shape and function of teeth.

    • To improve the aesthetics of teeth, such as shape, size and color.

  • Crown Materials

    Porcelain

    Properties

    • Aesthetic colour and translucency can match the natural teeth.

    • Not easily stained.

    • Hard and high in wear resistance.

    Disadvantage

    • Brittle and suitable for non-stress bearing area only

    Application

    Tooth veneer or crown

    To restore teeth with high aesthetic requirement, especially the front teeth.

    Porcelain fused to gold

    Properties

    • Aesthetic colour of outer surface is similar to natural tooth.

    • Strong and durable because of the gold alloy base.

    • Hard.

    Disadvantage

    More tooth substance needs to be removed from the facial surface of the tooth.

    Application

    Used on front teeth

  • Stainless Steel

    Properties

    • Not custom-made. It is preformed with several sizes.

    • Since the crown is not custom-made, the procedures of fitting are simple and the time taken is relatively short.

    Disadvantage

    • Silvery colour, unaesthetic

    • Non-stress bearing, not lasting

    • Since the crown margin is not closely adapted to the tooth, the margin is prone to accumulation of dental plaque which causes dental caries and periodontal disease

    Application

    Used on molars of deciduous teeth

    Gold Alloy

    Properties

    • Durable

    • High wear resistance

    • Gold alloy crown can be quite thin — only a small amount of tooth substance needs to be removed to accommodate it

    Disadvantage

    • Metallic colour, poor aesthetics

    Application

    Used at high stress bearing area where good aesthetics is not a must. For example, posterior teeth.

  • Bridge

    Conventional bridge preparation will destroy natural tooth substance and reduced the ease of tooth cleansing, hence dental implants are good alternative treatment options for replacing missing teeth.

    Purpose

    • To replace missing teeth in order to prevent the drifting of neighbouring teeth into the tooth space, which will result in crooked teeth or abnormal bite.

    • To restore the functions of teeth, including mastication, speech and aesthetics.

    Materials

    • Ceramic fused to metal

    • All ceramic (e.g. zicornia bridge)

    Mechanism

    • A bridge is being anchored by the teeth on either side of the tooth space; it can also be fixed by a metal wing extending from either side of the bridge.

    • A bridge can be used together with crowns.