The dental prosthesis is a manufactured product made by the hand of specialists in Dental, used to replace the toothing original lost or compromised for reasons functional and / or aesthetic. It also defines the denture dentistry that deals with the design and construction of prostheses, subject to the following requirements:
Functionality: concerns the restoration of proper chewing and joint function (open, close, left-right laterality, protrusion-retrusion and the correct pronunciation).
Resistance: The implants must withstand the weight of the chewing load and wear on the buccal liquid.
Safety: the prosthesis must be constructed of materials that are non-toxic and should not have "sharp edges" that may cause tissue damage.
Aesthetics: the artificial teeth should be as similar as possible to the natural ones and care must be taken not to alter the correct facial profile of the patient.
The fixed prosthesis is fixed to the elements pillar by cementation and can not be removed from the patient. Based on the functions, there are three types of fixed prostheses:
fixed prosthetic reconstruction: their task is to reconstruct the anatomy of the tooth removed and then protect it from complete destruction (eg, crowns, inlays, abutment);
fixed prosthesis replacement: replaces natural teeth with particular elements (eg intermediate elements of bridge prostheses);
fixed prosthesis fixation: has the ability to lock and properly distribute the chewing forces (eg ferrules fixation).
These elements if anchor themselves on the tooth or root residue are defined crowns, if they are based on adjacent teeth (suitably filed) with the aim of restoring missing teeth are called bridges, and when applied on implants inserted in the bone are defined prosthesis on implants. Are defined fixed prosthesis also veneers, which consist of shells of ceramic to be applied on the front teeth for aesthetic or functional purposes. In recent years, great importance has taken the computer-assisted construction of fixed prostheses with CAD / CAM technology.
Requirements modeling for fixed prosthesis
Each type of modeling for fixed prosthesis to meet the standard of performance, durability, safety and aesthetics must meet the following basic requirements.
Modeling anatomically perfect, you need to rebuild the affected tooth so as similar as possible to what the patient had in nature, so with all the features that had the healthy tooth, to this reconstruction, we make use of any other teeth present nell'arcata .
Contact point: to be rebuilt when modeling for three reasons: the uniform distribution of masticatory load on the entire arch, and the protection of individual alveolar dental ligament, to avoid the "migration" of the affected tooth or those nearby, for protect the area of the papillae from food stagnation and hence the possibility of secondary caries.
Proper occlusion: It is important to re-establish proper function of the prosthesis. If the occlusion is too low we may have the elongation of the affected tooth towards the antagonist or vice versa. If the occlusal load is excessive we might have damage to the tooth pulp (pulpitis) and alveolar-dental ligament (periodontal disease).
Right size of the interdental spaces and interstitial: If the size of the interdental spaces were too prominent, the area of the papillae not have a precise position, and we would have the possibility of stagnation of food, if they were too pronounced interstitial spaces, although the contact point of the food could slide over time cause secondary caries in the teeth.
Correct reconstruction of the axial curvature: this is the camber of each tooth in all vertical surfaces and is restored when modeling in the appropriate size. If the axial curvature is just accentuated the food frequently will impact the gums, causing redness and inflammation. If instead the axial curvature is very accentuated we stagnation of food and consequently secondary caries.
Rounding of the cusps: This is done to prevent the crown noble alloy that will be applied in the patient's mouth can damage the opposing tooth, as the alloys used in dentistry have an abrasion practically nothing. Keep in mind also the age of the patient to determine the inclination of the facet cuspidiane (inclined planes are those that are hypothetically to form on the slopes of the cusps in each direction starting from the top of the cusp same).
Modeling of the collar knife blade: in the parts of prostheses in which the tooth is reduced to the abutment crown that fits to go below the gum at the level of the collar must have a very thin thickness to said knife blade.
Radiography of a plant in seat
The crowns for single tooth implants of which at least the root is preserved. Are anchored or properly prepared tooth (stump) or through pins root canal, the root (crown Richmond). The crowns, as well as the elements of bridge, may be metal, ceramic metal, ceramic only. Currently we are presenting other useful materials for fixed dental prosthesis.
What bridges the dental element extract is replaced by a prosthesis which also includes the adjacent dental elements which are for this reduced to stumps and also prosthesis. The missing element along with abutment (stumps on which rests) form the bridge. Can be total ie including the entire arch (bridge prostheses circular) or partial comprising two or more elements. The abutment must be a number greater than or equal to the number of roots of the missing pillar, if it does not exist you are running a joint prosthesis. For girder is defined as the part of the structure used to support the item or items missing.
In this case the root element is missing replaced by a plant usually titanium and on this is cemented or screwed onto the prosthetic element. With implants you can replace individual teeth or building bridges or structures larger (Toronto bars, or similar) that can replace all the elements of the entire dental arch.
The porcelain veneers are thin ceramic plates that are cemented on the visible surface of front teeth. The teeth that receive a facet are slightly filed down to make room for the porcelain. However, their preparation is extremely conservative and must be maintained at the level of the most superficial portion of the tooth, the enamel. The enamel allows optimum adhesion of veneers to the tooth.
With the term "prosthesis" refers to all prosthesis suitable for the replacement of entire arches or parts of it. Are defined furniture as they can be easily removed from the patient during the course of the day.
Dentures are dentures, partial dentures and denture mixed-skeleton.
Partial denture with hooks
The partial denture is anchored by hooks or attacks on the remaining teeth. When the partial denture has a metal support structure is defined prosthesis skeletal or skeletonized and if mixed with precision attachments pillar elements of said prosthesis is combined. You can also establish a prosthesis type skeleton acetal or termopressata without metal hooks. It is also feasible a prosthesis Flexite, nylon-based and therefore without metal and with characteristics of biocompatibility and flexibility.
The total prosthesis falls between devices afisiologici, as masticatory loads are completely downloaded on the mucosa and underlying bone, because the residual teeth or roots are lacking (edentulous). Has the task of completely restoring the masticatory. In the execution of this prosthesis must respect the profile of the face (facial profile). It is better defined "Mobile total" as appears to be a device that the patient himself can remove and reinsert at any time of the day.
It is a device able to replace entire edentulous arches now, consists of a supporting structure in acrylic resin. The teeth are the teeth of the trade is used in ceramics (little used) and either acrylic or composite. With teeth products currently are obtained excellent aesthetic results: fundamental is the skill of the dental technician that, in particular for the front teeth, is able to confer on the prosthesis a natural appearance that is well suited to the face and expressions of the patient.
If the saddle edentulous was little detected or otherwise to increase the retention of the denture is possible, if the amount of residual bone is sufficient, resorting to surgery implant. In such a case would be inserted in the edentulous ridge of the plants with anchoring function (generally the technique for overdentures with retention spherical, are inserted in the lower jaw 2 implants in the area of the canines).
Taken from Wikipedia