The replacement of the natural teeth in the arch and their associated parts by artificial substitutes- GPT.
- Removable complete dentures
- Fixed complete dentures
Functions of a Complete Denture
- Aesthetics: The complete denture should restore the lost facial contours, vertical dimension, etc. Artefacts like stains can be incorporated in order
to improve the aesthetics.
- Mastication: A complete denture should have proper balanced occlusion in order to enhance the stability of the denture.
- Phonetics: One of the most important functions of a denture is to restore the speech of the patient.
Components of Complete Denture
Surfaces of A Complete Denture
- Impression surface (Intaglio surface): "That portion of the denture surface which has its contour determined by the impression"- GPT
This surface refers to the surface of the denture that will be in contact with the tissues (basal seat area and limiting structures) when the denture is seated in the mouth. This surface is a negative replica of the tissue surface of the patient. It should be free of voids and nodules to avoid injury to the tissues.
- Polished surface (Cameo surface): "That portion of a surface of a denture which extends in an occlusal direction from the border of the denture and includes the palatal surfaces. It is the part of the denture base which is usually polished, and it includes the buccal and lingual surfaces of the teeth"
This surface refers to the external surfaces of the lingual, buccal, labial flanges and the external palatal surface of the denture. This surface should be well polished and smooth to avoid collection of food debris.
- Occlusal surface: "That portion of the surface of a denture or dentition which makes contact or near contact with the corresponding surface of the opposing denture or dentition" —GPT.
This surface refers to the occlusal surface of the denture teeth. It resembles the natural teeth and usually contains cusps and sluice ways to aid in mastication.
Parts of a Complete Denture
It is defined as, “That part of a denture which rests on the oral mucosa and to which teeth are attached” – GPT.
It is usually made in acrylic resin. In some cases metal denture bases are prepared. The denture base forms the foundation of the denture. It helps to distribute and transmit all the forces acting on the denture teeth to the basal tissues. It has the maximum influence on the health of the oral tissues. It is the part of the denture, which is responsible for retention and support.
Flange of a Denture
It is defined as, “The essentially vertical extension from the body of the denture into one of the vestibules of the oral cavity. Also, on the mandibular denture, the essentially vertical extension along the lingual side of the alveololingual sulcus”- GPT.
It has two surfaces, namely, the internal basal seat surface and the external labial or lingual surface. The functions of the flange include, providing peripheral seal and horizontal stability to the denture. The flanges are named based on the vestibule they extend into.
It is defined as, “The margin of the denture base at the junction of the polished surface and the impression surface”- GPT.
It is responsible for peripheral seal. The denture border should be devoid of sharp edges and nodules to avoid soft tissue injury. Overextended denture borders can cause hyperplastic tissue changes like Epulis fissuratum. On the other hand the border should not be under-extended as peripheral seal may be lost.
It is the most important part of the complete denture from the patient’s point of view. The functions of the denture teeth are aesthetics, mastication and speech. They are usually made of acrylic resin or porcelain.
Morphology of Teeth
- Anatomic Teeth:
It is defined as, “Teeth which have prominent pointed or rounded cusps on the masticating surfaces and which are designed to occlude with the teeth of the opposing denture or natural dentition” - GPT.
Anatomic teeth have a 33° cusp angle. Cusp angle can be defined as, “The angle made by the slopes of the cusp with a perpendicular line bisecting the cusp, measured mesiodistally or buccolingually” - GPT.
They are the most commonly used of all the types available because they resemble the natural teeth and provide good aesthetics and the psychological benefit to the patient. While choosing the type of teeth for a patient, the incisal and condylar guidance of the patient, should be analyzed.
- Semi-anatomic Teeth:
These teeth have cusp angles ranging between 0° and 30°. The cusp angles are usually around 20°. They are also called modified anatomic teeth.
- Non-anatomic or 0° or cuspless Teeth:
Non-anatomical teeth are defined as, “Artificial teeth with occlusal surfaces which are not anatomically formed but which are designed to improve the function of mastication” - GPT.
Cuspless teeth are defined as, “They are teeth designed without cuspal prominences on the occlusal surfaces” - GPT.
Zero degree teeth are defined as, “Artificial posterior teeth having no cusp angles in relation to the horizontal occlusal surfaces” - GPT.
These teeth have 0° cusp angles. These designs evolved to over-come the disadvantages of the normal anatomic teeth. These teeth do not provide balanced occlusion. Balanced occlusion in dentures with these teeth is obtained by balancing ramps and compensatory curves.
- Cross Bite Teeth:
These teeth are used in jaw discrepancy cases leading to a posterior cross bite relationship. Here the buccal cusps of the maxillary teeth are absent. Instead there is a large palatal cusp, which rests on the lower tooth.Gysi in 1927 designed the cross bite tooth.
- Metal Insert Teeth (VO Posteriors):
Hardy designed the first metal insert tooth and he called it the “Vitallium occlusal”. Here each tooth will look like the fusion of two premolars and one molar. On the occlusal surface of these teeth, a Vitallium ribbon is embedded in a zigzag pattern. The Vitallium metal insert is not totally submerged into the tooth, instead it is slightly raised above the occlusal surface. On occlusion, the metal-to-metal contact produces greater cutting efficiency.
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