Introduction to Fixed Prosthodontics - Branch of prosthodontics focused on permanently affixed dental prostheses - Examples include crowns, bridges, inlays, onlays, and veneers - Prosthodontists are dentists specialised in fixed prosthodontics - Advantages include improved strength in large restorations and aesthetic appearance - Selection of suitable repair involves consideration of materials, tooth destruction, placement, and neighboring teeth

Preparation Techniques and Dimensions - Irreversible removal of tooth structure during crown preparation - Restorations have impaired structural and functional integrity compared to natural teeth - Treatment planning and recommendations may vary among dentists - Crown and bridge work traditionally requires multiple visits - Benefits of intervention generally outweigh the drawbacks - Amount of tooth structure removal depends on the restoration material - Full gold crown requires minimum tooth reduction of 0.5mm - Porcelain application to gold crown requires additional 1mm of tooth structure removal - Porcelain or ceramic crowns require 2mm of tooth reduction - Insufficient tooth structure may require build-up material or post and core

Taper and Margin - Prepared tooth needs a certain degree of taper for proper placement of the restoration - No undercuts should be present on the prepared tooth surface - Excessive taper limits the grip of the crown on the tooth - Recommended taper is 3° around the entire circumference of the prepared tooth - Combined taper of 6° provides proper fit and grip for the crown - Margin is the most coronal position of untouched tooth structure - Margin should be smooth and well-defined for proper adaptation of the restoration - Acceptable distance from tooth margin to restoration margin is 40 to 100 nm - Margin placement in aesthetic zone should be as apical as possible - Violation of biologic width may occur if the margin is placed too subgingivally

Ferrule Effect - Incorporation of the ferrule effect is crucial when restoring with a crown - The crown should envelop a certain height of tooth structure to protect the tooth - Similar to the grasping of bristles by a ferrule on a broomstick

Restoration Types - Crowns are used to cover teeth and may be referred to as caps - Teeth to be crowned are prepared by a dentist - Dental technician constructs the crown using models and impressions - Crowns can be made of gold, porcelain, or a combination of the two - Zirkonia Oxide crowns are gaining popularity due to their translucency and durability - Bridges are used to span edentulous areas by connecting to adjacent teeth - Teeth supporting the bridge are called abutments - Bridges can also refer to single-piece multiple-unit fixed partial dentures - Part of the bridge replacing a missing tooth is known as a pontic - Some cases may have several pontics for multiple missing teeth - Inlays are restorations that lie within the cusps of teeth - Considered more conservative than onlays or crowns - Less tooth structure is removed during preparation - Used when tooth destruction is less than half the distance between cusp tips - Onlays cover, protect, or reinforce one or more cusps of teeth - Indirect method for restoring teeth - Used for extensive tooth destruction due to caries or trauma - Provide more coverage than inlays - Preserve more natural tooth structure compared to crowns