Prosthodontics tutorial: the production of complete dentures

(a) Classification of full denture impressions

1. According to the number of times to take the impression

(1) primary impression method: with the teeth suitable finished tray as well as alginate impression material completed at once

(2) secondary impression method: consisting of the initial and final impressions

2. According to the taking of the impression, the patient's mouth open and closed

(1) open-type impression

(2) closed-type impressions

(1) open-type impressions

(1) open-type impressions

(1) open-type impressions

(2) closed-type impressions

(1) Open impression

(2) Closed impression

3. According to whether pressure is exerted on the mucosa when the impression is taken

(1) Mucosal static impression

(2) Mucosal motion impression

4. Making of individual trays

(1) Individual trays made from room-temperature curing plastics are made by drawing a line around the edges, adding inverts as appropriate, and applying a separating agent. Appropriate to add the inverted concave, coated with a separator, mixing self-curing plastic materials, evenly coated, individual trays 2 - 3mm can be

(2) the method of modification of the initial impression of the production of individual trays in the initial impression of the organization of the surface of an even layer of scraping around the edge of the scraping of 1-2mm.

5. Edge of the whole plastic

6. p> 6. Take the final impression

When the impression is taken out, it is necessary to pay attention to let the patient gargle or puffing, dripping from the edge of the lip side, so that the impression is taken down.

(B) Steps for taking the impression

1. Preparation before taking the impression

2. Taking the initial impression

The groove ridge is shaped like a concave shape, and the doctor stands at the right rear of the patient, holds the tray in his right hand, and pulls open the left corner of the patient's mouth with the left finger, and rotates the tray into the patient's mouth, with the handle of the tray aligned to the midline of the face, and pulling open the upper lip, the tray is directed to the edentulous jaw, and presses it to the upper and posterior sides. Apply pressure, stabilize the tray with the right middle finger and the index finger, the left thumb is placed on the lateral side of the cheek, the index finger is on the medial side of the cheek, downward anterior-inferior movement for several times, the other side is the same, change hands. Lip side, the middle finger of both hands to stabilize the tray, the thumb on the outside of the lip, show the finger on the inside of the lip, pulling the upper lip downward inward motion several times, can be.

Second, the model

1. Peri-mold perfusion method

2. General perfusion method: a. Pay attention to the production of the posterior embankment area b. Hard gypsum hardening time of about one hour c. Ordinary gypsum hardening time of about half an hour

Third, the jaw relationship record

Jaw position record refers to the use of the tooth tooth coaptation bracket to determine and record in the patient's face the lower 1/3 of the The jaw position record is to determine and record the relationship between the lower 1/3 of the patient's face and the upper and lower jaw positions when the condyles on both sides are in the physiological posterior position of the mandibular joint concavity. Including vertical and horizontal relationship record two parts to distinguish between the following positions: the relationship between the position; orthodontics; anterior extension of the dental position and lateral dental position

(a) determine the vertical distance

Vertical distance: for the natural teeth into the orthodontics, the bottom of the nose to the bottom of the chin, that is, the face of the lower 1 / 3 of the distance.

1. Methods

(1) The vertical distance using the resting jaw position minus the resting dentition gap

(2) the pupil to the cleft of the mouth is equal to the vertical distance of the method

(3) Facial shape observation method

Vertical distance restoration is incorrect: restoration of the too large, the face of the lower 1/3 increase; restoration of the too small, the face of the lower 1/3 decrease

p> (II) Horizontal jaw position relationship record

1. Gothic arch tracing method

2. Direct occlusion method: (1) rolled tongue after licking method (2) swallowing occlusion method (3) posterior teeth occlusion method

3. Muscle monitor method

(III) Determination of the vertical distance and the specific steps of orthogonal relationship position record

1. Maxillary dentition bracket Fabrication

(1)Fabrication of the base bracketTwo layers of wax sheets were baked and softened and glued together to make a close fit with the model

(2)Fabrication of the dentition dyke

The wax sheets were baked and softened and rolled into a wax strip of 8-10mm, and glued to the base bracket according to the shape of the alveolar ridge, which was then introduced into the mouth to form a dentition dyke while the dyke was soft and the dentition plane was formed by pressing the surface with a dentition plane gauge, and attention was given to the fact that the anterior part of the dentition dyke leaked out below the lower edge of the lower lip for about 2mm, and was connected to the pupil for about 2mm. 2mm, and the pupil line parallel to the lateral view and the nose and ear screen line parallel.

2. Fabrication of mandibular brackets and recording of centricity

(1) Determine the height of the mandibular brackets while obtaining centricity by the method described above

(2) Modify the height of the prefabricated mandibular brackets before taking the records

3. Gothic arch tracing method of obtaining centricity

4. Verify the records of the jaws and check the perpendicular distance to see if the distance is appropriate. Check if the centering relationship is correct

5. Draw marking lines on the labial surface of the dentition embankment for the center line, mouth angle, lip height line, and lip height line.

(D) Maxillary frame

Maxillary frame: is a fixed upper and lower jaw bracket and the model of the instrument

1.Classification of the jaw frame

According to the degree of the jaw frame simulation of mandibular movement is divided into: simple jaw frame; average value of the jaw frame; semi-adjustable jaw frame; full-adjustable jaw frame

2.HANAUH2-type jaw frame

3.Facial arches

6. Determine the inclination of the lateral condylar guide

7. Determine the inclination of the incisal guide

(5) Alignment of teeth

1. Selection of the artificial teeth

(1) Texture: plastic and porcelain teeth

(2) Form, color, and size

2. Alignment of the teeth

(1) Aesthetic principle: Restore the shape of the lower 1/3 of the patient's face. The shape of the lower 1/3 of the patient's face should be restored to harmonize the proportion between the lower 1/3 of the face and the whole face, so as to make the person look young and give him a sense of beauty. The curvature of the teeth should be consistent with the jaw arch type, square and round, pointed round, oval, the position of the upper front teeth to set off the upper lip fullness, to achieve the following points: rows of teeth to reflect the patient's personality, according to the face, age, skin color, and so on the selection of teeth.

(2) Tissue health function

1) The arrangement of artificial teeth should not hinder the activities of the tongue, lip and cheek muscles, and be in a position of muscle balance.

2) The dentition plane is parallel to the nasal ear screen line, and its height is located at the most prominent lateral edge of the tongue, which is convenient for the tongue to send food to the posterior dentition surface, and is conducive to the stability of the denture in the functional state. The posterior teeth should be lined up on the top of the alveolar ridge as much as possible, so that the dental force is transmitted to the alveolar ridge in the vertical direction

3) If the alveolar ridge is more resorbed, the inclination of the posterior teeth should be adjusted according to the inclination direction of the alveolar ridge slope, so that the dental force is transmitted to the alveolar ridge in the vertical direction as much as possible, and if the alveolar ridge is severely resorbed, attention should be paid to the fact that the dental force should be located at the lowest place in the alveolar ridge, so as to minimize the denture's bucking in the functional state.

4) The anterior teeth are arranged into a shallow overdenture, shallow coverage, orthodontics when the anterior teeth do not contact and at least 1mm range in the anterior extension and lateral movement, the lower teeth along the upper teeth bevel free sliding.

5) Balanced dentition contact when sliding freely between the upper and lower teeth,

6) Reduction of instability in the functional state, by appropriately lowering the non-functional cusps, e.g., buccal cusps of upper molars and lingual cusps of lower molars, and reduction of denture wobble when grinding food.

(3) Principle of masticatory function

3. Specific methods of tooth arrangement:

(1) Alignment of upper anterior teeth

Precautions for the alignment of anterior teeth:

1) The alignment of upper anterior teeth should be adjusted appropriately in the patient's mouth, with the patient's consent

2) For patients with maxillary protrusion and mandibular retrusion, the appropriate increase in the coverage should be made, to leave the speaking and chewing space

2) For patients with maxillary protrusion and mandibular retraction, it is necessary to appropriately increase the coverage, to leave the speaking and chewing space. Speaking and chewing space

3) For patients with mandibular protrusion and maxillary retrusion, the teeth should be aligned as far as possible into normal dentition or opposite edge dentition

4) The cutting guide should be 15 degrees

5) Lower anterior teeth alignment can be carried out after the upper anterior teeth are lined up, or after lining up the upper anterior and all the posterior teeth

(2) Upper posterior teeth alignment

The alignment of posterior teeth should be adjusted appropriately in the patient's mouth, with the patient's consent

Allowance of posterior teeth alignment

Allowing for the patient's consent

The patient's consent is required. Precautions:

1) The functional cusps of the posterior teeth are the buccal cusps of the first premolar, the lingual cusps of the upper second premolar, and the proximal mesial lingual cusps of the maxillary molars. The functional cusps need to be lined up on the alveolar ridge apex contiguous line, and have a good cuspal fossa contact relationship with the maxillary fossa of the jaw.

2) There should be no occlusal interference with all non-functional cusps during horizontal movement in any direction, and occlusal equilibrium between individual teeth and between the bilateral arches.

3) When the alveolar ridge is in good condition and the relationship between the upper and lower jaws is normal, the alignment of the posterior teeth should be parallel and symmetrical to each other in both sagittal and frontal views.

4) If the inferior arch is short, several rows of teeth can be subtracted, minus one premolar or second molar.

5) If the alveolar ridge is severely atrophied, reduce the number of rows of teeth and confirm the center of mastication by establishing the lowest point of the alveolar ridge as the center of mastication, and arranging the molar teeth on it.

(F) Balanced dentition

Balanced dentition: refers to the orthodontics and mandibular anterior extension, lateral movement and other non-orthodontics, the upper and lower jaw related teeth can be contacted at the same time. It is the main difference between full denture and natural teeth occlusion form.

1. Classification of balanced dentition:

1) Balanced orthodontics: When the mandible is in orthodontics, there is a wide and uniform contact between the maxillary and mandibular artificial teeth with cusp and fossa staggered area called balanced orthodontics.

2) Non-Central Dental Balance: Anterior Extension Dental Balance: When the mandible is extended forward to the upper and lower anterior teeth relative to each other, there is contact between the anterior and posterior teeth in the process of sliding back to the orthodontics, multi-point contact, three-point contact, and complete contact in the anterior extension dental balance. Lateral dentition equilibrium: when the mandible to the side for occlusal contact sliding movement, both sides of the posterior teeth are position lateral dentition equilibrium.

3. Theory of balanced dentition: five factors and ten laws

Five factors:

1) Condylar guide slope: the angle of intersection between the condylar groove and the horizontal plane, with anterior extension dentition relationship record to transfer condylar slope to the dentitional frame

2) Incisal guide slope: for the intersection angle between the incisal guide disk and the horizontal plane.

3)Compensation curve: the bilateral cusps to the buccal cusp of the second molar are connected to form a convex downward curve.

4) Cusp slope or cusp height: When the mandible moves forward, the proximal mesial slopes of the buccal cusps of the lower posterior teeth and the distal mesial slopes of the lower posterior teeth rub against each other. The angle of intersection between the cusp slopes of the lower posterior teeth and the base of their respective cusps is known as the cusp slope.

5) Positioning plane obliquity: from the upper mesial incisor proximal mesial incisors to the second molar buccal cusp connected to a triangular plane positioning plane and orbital auricular plane intersected by the angle known as the positioning plane obliquity.

Ten laws (like the weights of a balance):

(1) As the slope of the condylar guide increases, so does the curvature of the compensation curve.

(2) As the condylar guidance skew increases, so does the positioning plane skew.

(3) Condylar guidance skew increases and tangential guidance skew decreases.

(4) Condylar guidance skew increases and apical skew increases. (Gradual increase posteriorly)

(5) Compensatory curve curvature increases, as does positioning plane slope.

(6) Compensation curve curvature increases, and so does the tangential guide slope.

(7) The compensation curve curvature increases and the apical skew decreases. (Decreases gradually backward)

(8) The positioning plane slope increases, and so does the tangential guide slope.

(9) The positioning plane slope increases and the apical slope decreases.

(10) The slope of the tangential guide increases, and the slope of the cusp also increases (gradually increasing forward)

(VII) Trial fitting of complete denture

1. Denture in the jaw holder

Checking the base: whether the edge of the denture base is properly stretched out, and whether the base is stable on the model

Checking the teeth row: whether the front teeth are covered with normal overdentures, and whether the back teeth are aligned on the top of the alveolar ridge

Checking the teeth row: whether there is normal overdentures, whether the rear teeth are aligned on the top of the alveolar ridge, and whether the teeth are aligned on the top of the alveolar ridge. Whether the front teeth have normal overdenture coverage, and whether the back teeth are arranged in the appropriate position on the line connecting the top of the alveolar ridge

2. Inspection after the denture is put into the mouth

Harmonization of the local proportions: Whether the patient's appearance is harmonized in the lateral view and the frontal view.

Check the relationship between the jaws: put both hands on the temporal part of the patient and repeatedly make a centering bite.

Examination of the anterior teeth: check the shape, position and arrangement of the artificial teeth, and the relationship between the anterior teeth and the lips.

Examination of posterior teeth: check whether the posterior teeth are properly aligned, whether the dentition plane is at the lingual margin or slightly lower, check whether the denture is stable or not, and check whether the denture is functionally stable or not by gently applying pressure on the central fossa of the mandibular posterior teeth and the lingual cusp of the maxillary posterior teeth with the help of an instrument.

Check the base: whether the edge is suitable, especially the maxillary posterior edge, the mandibular molar back cushion to check the vertical distance and pronunciation

(H) the completion of the full denture

1. Wax type completion

(1) fixed wax base on the working model, denture wax type after the trial wear, such as the use of the temporary base, it should be closely attached to the work of the model, the appropriate wax, to maintain the thickness of the base as thin as possible, and to keep it as thick and thin as possible. Keep the denture base bracket thickness as uniform as possible, edge thickness in 2,5-3mm buffer zone thickening, stretching to the migration groove.

(2) the formation of gingival shape: with a carving knife in the surface of the artificial teeth at an angle of 45 degrees from one side of the tooth gap along the neck of the artificial teeth guide the other side of the tooth gap, carving out the shape of the gingival margin.

(3) The formation of the shape of the polished surface: wax mold equivalent to the gingival position, the formation of the length and prominence of the root of the tooth, the formation of a concave surface in the buccal-lingual-palatal surface of the posterior teeth to adapt to the activities of the tongue.

(4) denture wax pattern of polishing: the teeth on the excess wax scraped clean in the formation of wax pattern, do not touch the position of the teeth, and affect the lower, maxillary teeth occlusal relationship.

2. Boxing

3. Opening the box and removing the wax

4. Filling the plastic

5. Checking the occlusion after heat treatment and then on the dental bracket