Dental preparations must be carried out according to previously established scientific principles, which are: mechanical, biological and aesthetic. This constitutes one of the most important stages in the construction of a dental prosthesis, either as an individual crown or a fixed dental prosthesis retainer.
The metal-ceramic crown has always been the full-coverage restoration most used in dentistry, and is still considered the “gold standard” because it derives its aesthetics from natural appearance due to the translucence of the ceramic and the strength of the metallic substructure.
At the present time the development of reinforced vitreous ceramics such as lithium disilicate allow the construction of metal free crowns with satisfactory esthetics and mechanical properties to make single crowns and short extension fixed dental prostheses in the anterior area with similar clinical survival to the metal-ceramic crown.
Failures in the dental preparation lead to the failure of the restoration either by insufficient reduction of the dental structure that could cause over-contour, having a high aesthetic compromise and gingival inflammation affecting the periodontal health of the patient, color alteration (opacity or translucent), and insufficient thickness of the restorative material.
If excessive tooth wear occurs, irreversible pulp damage, weakening of tooth structure and decreased retention and resistance affecting biomechanical behavior can occur.
(AMAZON)
If the preparation of the cervical termination is located deep, invading the periodontal biological space, one of the following four pathological alterations would occur: infra-osseous pocket formation, gingival recession, localized bone loss, localized gingival hyperplasia or a combination of the alterations described above.
