1. Cervical finish line
1.1. peripheral extension of a tooth preparation or the terminal portion of the prepared tooth
1.2. Functions
1.2.1. measure the amount of tooth structure
1.2.2. evaluate the accuracy of the impression
1.2.3. evaluation of the quality of the Die
1.2.4. evaluation of the restoration
1.2.5. determining whether the restoration is fully seated.
1.3. shape/design of margin
1.3.1. without overextension or unsupported enamel.
1.3.2. Ease of identification
1.3.3. distinct boundary to which wax pattern
1.4. Types
1.4.1. Shoulder
1.4.1.1. ADV
1.4.1.1.1. Bulk of restorative material
1.4.1.2. DisADV
1.4.1.2.1. Less conservative
1.4.1.3. Indications
1.4.1.3.1. Facial margin of metal ceramic crown
1.4.2. Chamfer
1.4.2.1. ADV
1.4.2.1.1. Distinct margin,adequate bulk,easy control
1.4.2.2. DisADV
1.4.2.2.1. Care needed to avoid unsupported enamel lip
1.4.2.3. Indications
1.4.2.3.1. Cast metal restoration
1.4.2.3.2. Lingual margin of metal ceramic crown
1.4.2.3.3. full veneer metal restoration.
1.4.2.4. Properties
1.4.2.4.1. negative image of a round-ended tapered diamond.
1.4.2.4.2. exhibit least stress to the underlying cement.
1.4.2.4.3. can be cut with round-end tapered diamond.
1.4.2.4.4. Conservative type when compared with shoulder finish line.
1.4.3. Beveled shoulder
1.4.4. Feather edge
1.4.5. Sloped shoulder
1.5. Location
1.5.1. Supra gingival margin
1.5.1.1. above the free gingiva
1.5.1.2. ADV
1.5.1.2.1. easier to prepare accurately without trauma to soft tissue.
1.5.1.2.2. can be situated on hard enamel.
1.5.1.2.3. easy to clean.
1.5.1.2.4. Impressions are easy to made
1.5.1.2.5. Restoration can be easily evaluated at recall visits
1.5.1.3. DisADV
1.5.1.3.1. Poor aesthetics
1.5.2. Sub gingival margin
1.5.2.1. below the free gingiva
1.5.2.2. Indications
1.5.2.2.1. Dental caries, cervical erosion
1.5.2.2.2. when crown lengthening is not indicated.
1.5.2.2.3. Proximal contact area extending to the gingival crest.
1.5.2.2.4. Need for additional retention.
1.5.2.2.5. Modification of the axial contour is indicated.
1.5.3. Equigingival margin
1.5.3.1. At the level of free gingiva
2. Shillingburg
2.1. 4 basics
2.1.1. PRESERVATION OF TOOTH STRUCTURE.
2.1.1.1. Should use Partial veneer (versus) Full veneer crown
2.1.1.2. Supra-gingival margin (versus) sub- gingival.
2.1.2. RETENTION
2.1.2.1. prevents removal of the restoration along the path of insertion or long axis
2.1.2.2. essential element
2.1.2.2.1. two opposing vertical surfaces
2.1.3. RESISTANCE
2.1.3.1. prevents dislodgement of the restoration by forces directed in an apical or oblique direction
2.1.4. STRUCTURAL DURABILITY.
2.1.4.1. Restoration must contain bulk of material that is adequate to withstand the forces of occlusion
2.1.4.2. Only this way the occlusion will be harmonious and axial contours normal.
2.1.4.3. Achieved it
2.1.4.3.1. Occlusal reduction.
2.1.4.3.2. Functional cusp bevel.
2.1.4.3.3. Lack bevel results
2.1.4.3.4. Axial reduction.
2.1.4.4. Improving Factors
2.1.4.4.1. Offest
2.1.4.4.2. Occlusal shoulder
2.1.4.4.3. Isthmus
2.1.4.4.4. Proximal groove
2.1.4.4.5. Box
2.1.5. MARGINAL INTEGRITY.
2.1.5.1. should closely adapt to the cavosurface finish line
2.1.5.2. Finishing line
2.1.5.2.1. finish line should be placed in an area where the margins can be finished by the dentist easily and kept clean by the patient.
2.1.5.2.2. should be placed in enamel
2.1.5.2.3. Mostly Placed supragingva
2.1.5.2.4. Supgingiva in case:
2.1.6. PRESERVATION OF PERIODONTIUM
2.1.6.1. placement of finish lines has a direct bearing on the ease of fabrication and the ultimate success of the restoration.
3. Rosential
3.1. 3 basics
3.1.1. Biological
3.1.1.1. Factors
3.1.1.1.1. Harmoniuous occlusion
3.1.1.1.2. Avoidance of over contouring
3.1.1.1.3. Supragingival margins
3.1.1.1.4. Protection against fracture
3.1.1.1.5. Conservation of tooth structure
3.1.1.2. Consideration
3.1.1.2.1. Prevention of damage during tooth preparation
3.1.1.2.2. Soft Tissues
3.1.1.2.3. Pulp injury
3.1.2. Mechanical
3.1.2.1. Retention forn
3.1.2.1.1. prevents restoration from becoming dislodged by such forces parallel to path of withdrawal is known as retention.
3.1.2.1.2. Factors
3.1.2.2. Resitance form
3.1.2.2.1. Prevents dislodgment of the restoration by the forces directed in an apical or oblique direction
3.1.2.2.2. enhance the stability of a restoration and resist dislodgement along an axis
3.1.2.2.3. Factors
3.1.2.3. Deformation
3.1.2.3.1. restoration must have sufficient strength
3.1.3. Esthetic
3.1.3.1. minimum display of metal
3.1.3.2. Maximum thickness of porcelain
3.1.3.3. Porcelain occlusal surface
3.1.3.4. Subgingival margin
3.1.3.5. Options for esthetic
3.1.3.5.1. partial veneer crowns
3.1.3.5.2. metal-ceramic restorations
3.1.3.5.3. all-ceramic restorations