Try in of complete denture

Try in of complete denture

INTRODUCTION • GUIDELINES TO FOLLOW BEFORE TRY IN APPOINTMENT • SIGNIFICANCE OF TRY IN APPOINTMENT • THE ROLE OF THE DENTIST • PREPARATION OF PATIENT AND OBSERVER FRIEND • REQUIREMENTS FOR WAXED DENTURE • - OCCLUSION • - WAX CONTOUR • - NEATNESS • THE TRY- IN APPOINTMENT • TRY- IN OF MANDIBULAR DENTURE AND MAXILLARY • DENTURE • TRY- IN OF BOTH DENTURES TOGETHER

PERFECTION AND VERIFICATION OF JAW RELATION • RECORDS • ECCENTRIC JAW RELATION RECORDS • PERFECTION OF THE POSTERIOR PALATAL SEAL • CREATING FACIAL AND FUNCTIONAL HARMONY WITH • ANTERIOR TEETH • SECURING PATIENT ACCEPTANCE • CONCLUSION

Definition • Trial Denture is a preliminary arrangement of denture teeth that has been prepared for placement into the patient’s mouth to evaluate esthetics and maxillomandibular relationship. • Try-in/ Trial placement/ Trial fitting is a process of placing the trial denture in the patient’s mouth for evaluation .

GUIDELINES TO FOLLOW BEFORE PROCEEDING FOR TRY IN APPOINTMENT • The patient is advised to leave the old denture out for a period of 24 hours prior to try in appointment . This allows the oral tissues to return to their resting form. • Trial dentures should be removed from the articulator and placed in a bowl of cold water as to prevent the displacement of teeth in wax. • When the retention of denture is in suspicion , it is advised to use a small amount of adhesive powder. The dentist must always be alert to avoid not only adverse tissue reaction but also mental reaction.

SIGNIFICANCE OF TRY IN APPOINTMENT • Gives the patient an opportunity to view the teeth arrangement and facial esthetics and suggest alterations before final processing of the denture.

Enable the dentist a chance to evaluate the denture prior to the final processing ... > Evaluation of retention , Stability and Support. > Evaluation and verification of vertical dimension of occlusion. > Evaluation and verification of centric relation and centric occlusion. > Evaluation and verification of facial esthetics. > Evaluation and verification of teeth arrangement and facial esthetics ( teeth should be set as nearly from where they grew) > Evalution and verification of denture base contour.

To make additional interocclusal record (if needed ) for furthur programming of the articulator. • To complete and confirmthe posterior palatal seal extension (PPS) • To proceed to subsequent procedures after final approval by dentist, patient and patient associate.

THE ROLE OF THE DENTIST According to Dr. S. Howard payne in an article on trial dentures In DCNA 1977— “ It is sad but true that only 5% of dental students seem to have an intitutive or native artistic ability. Most of the students gradually develop concepts of color, size , form and arrangement by observation of the natural teeth and what their instructors show them . Many of them in their total reliance upon the technician's stereotype arrangements, accounts for too many of patients with FALSE TOOTH LOOK” Beauty lies in the eye of the beholder and like a portrait artist , the dentist can always say , ‘this is the way it looks right to me’.

Just as dentists vary in their native artistic ability, so do patients. The intelligence level and the educational background seem to be significant in the demand for and appreciation of dentures, which look like natural teeth and are artistically correct.

Fulfilling the patient’s primary desire is important to the success of new dentures. If the patient’s ideas are completely wrong or just not practical, they should be tactfully explained away early in the procedure and a compromise worked out. At all times we must be aware of what our patients are thinking.

PREPARATION OF PATIENT AND OBSERVER FRIEND The patient is usually advised to come with spouse , a close friend or relative who could provide moral support and reassurance . However, both the observer and the patient must be preconditioned and thus prepared for the trial. Otherwise they can create more anxiety and doubts in the patient.

PREPARATION OF THE PATIENT • The patient is informed that the dentist will get to take the first look and • may want to make some changes before the patient is allowed to view • it. • FIRST ORAL FEEL : The first oral feelings • are temporary feeling of fullness. The • patient should be reassured that this feeling • of fullness will disappear over time.

EXCESSIVE SALIVATION : New dentures often stimulate excessive salivary flow. This is because the mouth often interprets the new dentures as foreign objects. The denture may appear to float. The patient should be assured that this is normal reaction to the new denture and will gradually decrease over the time.

EXCESSIVE LOOSENESS: Often the trail • dentures appear to be loose than it actually • is. This may be because of faulty tongue • position or excessive relief of the denture • base . Patient should be practiced for • correct positioning and also train to be • less active when first learning to chew. • The patient is assured that this too • will be overcome in final denture.

FINAL VIEWING : • After the dentist has finished evaluation and correcting ,the patient is allowed to view the denture. The mirror should be kept at normal conversational distance and the lighting should be natural . Patient is told to relax, smile , talk and count. Patient must not look at teeth alone, but at the teeth in relation to the mouth and entire face.

DENTIST LIMITATION : The patient often expect a lot out of the denture and can often be disappointed if those unrealistic expectations are not met. A patient should be forewarned that without accurate records of former teeth it is almost impossible to duplicate his / her former teeth. • The dentist can only strive to make the new denture based on certain measurements , experience and his own artistic ability.

However, the patient should be “encouraged to speak” out his doubts, suggestions or comments . The dentist must assure him that he will carefully consider his suggestions and incorporate them whenever possible but it must be dentist who make the FINAL DECISION .

ALTERATIONS : Once it has been that a alteration in form or arrangement are required , they are carried out. It is again tried in the mouth to see its effect. • FINAL APPROVAL: It is important that the dentist • get the final approval from the patient before processing • A denture constructed without consent (written) and • satisfaction is bound for disaster.

PREPARATION OF THE OBSERVER FRIEND The observer is asked to stand as a positive observer until he is asked to give his opinion. He must not showhis true feelings on his face. He must be warned that the patient will initially feel awkward and must be put at ease . Once the patient is relaxed he / she can be observed while counting, smiling etc. They can sometimedo more harm than good.

REQUIREMENTS FOR WAXED DENTURES: • There are several points about waxed trial dentures that will be considered. It is essential that the patient be able to visualize the dentures as they will appear in their final form. • Occlusion: • Occlusion usually has not been perfected • at the clinical try-in appointment. Many • dentists make eccentric records at this • appointment, with refinement of occlusion • as a laboratory procedure after the patient • has been dismissed.

There are two requirements at the try-in, to insure thatchanges in posterior tooth position will be minimal: i) that the occlusion is solid in centric relation with even posterior contact; and ii) that the posterior teeth are carefully positioned with average articulator settings..

ii) Wax Contour The wax contour around the teeth must be correct and contoured properly to give the correct tooth exposure. Palatal form, contour and thickness should be controlled at the try-in stage to obtain correct speech

iii) Neatness Neatness is an important phase of the try-in appointment. Since the experience Of patient is limited, they cannot judge technical adequacy. They do, however Form opinions and make very definite judgments based on non-technical factors. Since patients judge the adequacy of procedures on the minor items that they are able to observe, a rough mounting may be projected as casual or inaccurate construction of the dentures.

THE TRY IN Appointment From dentist’s stand point, there is a good deal more to be checked about the dentures than appearance, although this may be the patient’s main concern at this time. 1. Try-in of mandibular denture Check: i) Peripheral outline — a) Buccal & labial b) Lingual c) Posterior extension d) Under extension ii) Stability to occlusal stresses iii) Tongue space iv) Height of the occlusal plane

i) Check the peripheral outline Place the denture in the mouth and seat it on the ridge. The entire periphery should be checked to ensure that it is not over, or under extended. The mandibular denture should be placed into the mouth and the patient instructed to let the tongue lightly touch the inside of the denture to maintain the lingual seal.

The Buccal and Labial Periphery • Hold the denture in place with light pressure on the occlusal surfaces of the teeth, and move the cheek on one side gently, but firmly, upwards and inwards, thus simulating the motion it makes when chewing. Now relax the pressure on the teeth and observe if the denture rises from the ridge. If it does, trim the periphery where it is seen to be over extended until little or no movement occurs.

b) The Lingual Periphery Ask the patient to protrude his tongue to moisten the lips if the denture lifts at the back, it is over extended at the region of lingual pouch. Now, ask the patient to put the tip of his tongue as far back on his palate as possible; if the denture lifts in the front it is over extended anteriorly, probably in the region of lingual frenum.

c) Posterior Extension Ensure that the denture is extended upto the retromolar pad. The purpose of this is to buttress the denture against the backward pressure of the lower lip.

d) Under Extension Dentures must cover greatest possible area if maximum retention and stability are to be obtained. If the denture is found to be under extended in any part of the periphery as shown by the presence of a gap between it and the functional position of the surrounding mucous membrane, it implies an inaccuracy in the impression which must, therefore, be remade before proceeding further.

ii) Stability Under Occlusal Stresses This test is used to determine if occlusal stresses will be transmitted outside the ridge. Apply pressure with finger in the premolar and molar regions directed at right angles to the occlusal surface. If pressure causes the denture to tilt and rise, then it indicates that teeth are outside the ridge.

iii) Tongue Space Teeth should be arranged in neutral zone. The tongue being more mobile than the cheeks will cause greater instability of the lower denture if the teeth are set more to the lingual side of the neutral zone than the buccal side of it. If the tongue is cramped by the denture, lateral pressure will be exerted, producing instability when the tongue moves.

The causes of tongue cramping • Posterior teeth set inside the ridge • Molar teeth which are too broad buccolingually • Molar teeth leaning inwards.

iv) Height of the Occlusal plane To obtain maximum stability of a lower denture, the occlusal plane of the lower teeth should be very slightly below the bulk of the tongue, so that the tongue performs the majority of its movements above the denture and thus tends to keep the denture down.

2. Try-in of Maxillary Denture • Place the upper denture in the mouth and examine as follows • Check the peripheral outline • a) The buccal and labial • periphery is checked • as for the lower • denture

b) Position of posterior border Verify carefully that the posterior edge is correctly situated on the soft palate and that the post-dam area on the model has been placed correctly

Stability of maxillary denture Stability under occlusal load may be carried out as for the lower denture, but it is intended to check the closeness of adaptation of the base against the mucosa and the future support of the denture. Retention of maxillary denture Retention is checked by seating the denture with a finger on the vault of the palate and then attempting to remove the denture at right angle to the occlusal plane.

3. Both Dentures together Remove the upper denture from the mouth and chill in cold water for a few seconds, and then place both dentures in the mouth. If it is found necessary to improve the retention of the dentures when using a shellac type of base plate, some adhesive powder may be sprinkled on their fitting surfaces

Perfection and Verification of Jaw relation records The vertical dimensions and centric relation of edentulous jaws are tentatively established with the occlusion rims. After the preliminary arrangement of the artificial teeth on the occlusion rims, it is essential that the accuracy of the jaw relation records made with the occlusion rims be tested, perfected if incorrect, and then verified to be correct.

Patients should be advised to leave existing dentures out of the mouth for a minimum of 24 hrs or to have the existing dentures relined with a soft temporary material before the jaw relation records are perfected and verified at the time of the try-in appointment. This way the soft tissues of the basal seat will be rested and in the same form as they were when the final impressions were made

a) Verifying the Vertical Dimension The maxillary and mandibular trial dentures are placed in the mouth. The patient is instructed to close lightly so that the maxillary labial frenum can be checked to see that it is absolutely free. If the denture border causes binding of the frenum, the labial notch should be deepened.

The vertical dimensions of occlusion (VDO) and of rest (VDR) must now be given careful consideration, because the final positions of the anterior and posterior teeth will depend to a great extent on the amount of space that is available vertically. Unfortunately, however there is no precise scientific method of determining the correct occlusal vertical dimension. The acceptability of the dentures vertical relations depend on the experience and judgment of the dentist.

The following factors help in determining acceptable vertical dimension. • Pre extraction records • Amount of interocclusal distance with old dentures • Phonetics and esthetics • Study of facial dimensions and facial expression • Lip length in relation to the teeth • Amount of interocclusal distance between the teeth when the mandible is its rest position

b) Verifying Centric Relation After the vertical dimension has been determined centric relation is verified. This can be done by intra orally observing intercuspation or by an extra oral method on the articulator. Intra Oral Observation of Intercuspation The patient is guided into centric relation by a thumb placed on the antero inferior portion of the chin and the index fmgers bilaterally on the buccal flanges of the lower trial denture.

The patient pulls his lower jaw back as far as it will go and closes just until the back teeth make a “feather touch”. Then the patient closes tightly. Any error in Centric Relation will be apparent when the teeth slide over each other (TOUCH AND SLIDE), especially if anatomical teeth are used. A second closure made with the same instructions and a stop at first tooth contact will permit visual observation of any error.

ii. Eccentric Jaw relation Records and Perfection of Posterior Palatal Seal • Eccentric Relation Records • The path of the condyle in protrusive and lateral movements is noton a straight line. The shape of the mandibular fossa is an ogee curve as viewed in the sagittal plane. • The ideal amount of protrusion for making the record is the exact equivalent of the amount of protrusion necessary to bring the anterior teeth end to end. However, the mechanical limitations of most articulators require a protrusive movement of at least 6 mm so that the condylar guidance mechanisms can be adjusted.

b) Perfection of Posterior Palatal seal The posterior border of the denture is determined in the mouth, and its location is transferred on to the cast. A “T” burnisher or mouth mirror is pressed along the posterior angle of the tuberosity until it drops into the pterygo maxillary notch. The locations of the left right pterygomaxillary notches are marked with an indelible pencil.

The vibrating line of the soft palate, which is a guide to the ideal posterior border of the denture, is usually located slightly anterior to the fovea palatinae. However, the vibrating line may be on or slightly posterior to the fovea palatinae. The Dentist can decide by having the patient Say ‘ah’ thus vibrating the soft palate. The dentist observes closely and marks the vibrating line with an indelible pencil. The trial denture base is now inserted so that the indelible pencil line is transferred from the soft palate to the trial denture base, and the excess base plate is reduced to this line.

Basic Guides to develop Facial and Functional Harmony After an acceptable vertical relation of occlusion has been determined and the horizontal relation of the casts on the articulator has been verified for centric relation, the appearance of the patient is studied, and modifications are made in the arrangement of the teeth to obtain a harmonious effect with the patients face.

The guides include, a. Evaluation of the preliminary selection of the artificial teeth b. The horizontal orientation of the anterior teeth c. The vertical orientation of the anterior teeth d. Phonetics in orientation of the anterior teeth e. The inclination of anterior teeth f. Harmony in the general composition of the anterior teeth g. Refinement of individual tooth positions h. Harmony with SPA concept

Try in of complete denture