Helpful Hints For Clinic

Dentistry Is Not A Race

• Do not be in a hurry to complete the treatment or the procedure.

• There is nothing wrong with having your patient come back to finish a procedure.

• Remember this is a teaching institution and you are here to learn how to do things properly.

Be Prepared For Clinic

• Read your clinic manual so you understand the steps to complete that days procedure.

• Familiarize yourself with the materials that will be used.

• Complete any necessary lab procedures prior to the patient’s appointment. (i.e. Custom trays)

• This will allow you to be much more efficient and comfortable with that days appointment.

Cubical Set Up

• Obtain from dispensing the appropriate kit for that days treatment.

• Hook up everything that may be needed. (i.e. High and low speed suctions, air water syringe, and the hand pieces.)

• Lay out the instruments needed, gauzes, cotton rolls, floss, etc. Remember that the instruments were designed with a purpose in mind. (i.e. The articulating paper holder.)

• Do not take things out as you need them. This will only slow the treatment and give the patient the idea that the operator does not know what they are doing.

Diagnostic Casts

• Purpose:• Evaluate a patient’s occlusal scheme.

» i.e. Occlusal plane or premature contacts.

• Evaluate the alignment of the teeth.• Visually present to the patient treatment that may

be needed.• Custom tray fabrication.

Diagnostic Casts

• Importance is often underestimated and therefore not done properly.

• Need full extensions to cover all necessary anatomical landmarks.

• i.e. Hamular notches, retromolar pads, depth and shape of the vestibule, lingual flange and floor of the mouth.

• This allows for the proper custom tray fabrication.

• Cast trimming should provide a land area around the entire cast.

Common Mistakes With Diagnostic Casts

• Under extension of impression material.

• Over trimming of the casts.

• Use of the “dog dish” to form the base.• Not large enough to support or extend to the all

anatomical land marks.» i.e. Hamular notches, retromolar pads, and the full

vestibule.

Custom Trays

Crown and Bridge vs. Complete Dentures

Crown and Bridge Custom Tray

• Place the appropriate wax relief.• Allows for proper flow and uniform thickness of the

impression material.

• Tray stops on 3 to 4 teeth.• Place stops on nonfunctional cusps.• Keeps the tray stable.• Prevents over seating of the tray.

• Tray extensions.• Extends at least 4-6mm beyond the free gingival margin.• “U” or horseshoe shaped.• Displaces the cheek and tongue away from the margins.• Allows the heavy body impression material in the tray to

force the light body impression material down into the sulcus of the retracted tissue.

Edentulous Custom Trays

• Primary impression should include all the anatomical land marks.

• i.e. Tuberosities, hamular notches, retromolar pads, the full vestibule, floor of the mouth, and the lingual flange.

• Tray fabrication procedure.• Block out the undercuts, but not excessively.• Vaseline (lubricate) the cast.• Place one layer of base plate wax relief.

» Mx: cover the ridge, rugae, and the midline.» Mn: cover the ridge, and the retromolar pads.

• Vaseline the top of the relief wax and the cast.» The relief wax remains in the tray throughout the border

molding procedure. The wax stabilizes the tray and provides room for the impression material to flow uniformly.

Adjusting the Edentulous Custom Tray Intraorally

• Remember, do not remove the relief wax until the border molding is complete.

• Prior to border molding the tray must be adjusted.

• The tray peripheries are trimmed back approximately 2-3mm short of the vestibular depth.

• The tray should not be displaced while manipulating the cheek to shorten the depth of the vestibule as much as reasonably possible.

Border Molding With Compound

• Set up.• Properly adjusted tray with the relief wax still in place.• Hot water bath filled to the line inside of the water pan and heated to

140-142 degrees Fahrenheit. • Compound sticks, Bunsen burner, and the Hanau torch.

• The compound should be added in quadrants.• Be sure that the tray and compound is dry before adding any

compound to the tray.• The Bunsen burner is used to soften the compound so it can be

placed on the periphery of the tray.• The Hanau torch uniformly softens the newly placed compound as

well as part of the recently placed compound.» This will give the compound the appearance of having been

placed all at once. Rather than a bunch of stops and starts.• The compound is then tempered in the water bath to prevent

burning the patient’s tissue.

Trimming An Edentulous Cast

• Maintain a land area of ~6mm wide.• Aids in the flasking and processing of the denture.• Prevents the accidental trimming away of

anatomical land areas.

• Trim the land area to a height of 3mm short of the vestibular depth.

• If too long, undercuts are created which will make it difficult to remove the base plate.

• Allows for an accurate vestibular shape during processing.

Wax Try In

• The teeth are to be set, festooned, and checked off by an instructor prior to the patient’s appointment.

• Set the teeth with the appropriate curve of Spee and Wilson.

• Important if a balanced occlusion is to be achieved.

• Festooning• Clean the wax off the teeth showing the proper amount of tooth.• Bulk the wax for the desired amount of lip support.

» Makes a difference how much of the anterior teeth will show.

• The patient’s approval is very important.

• Vertical dimension of occlusion and jaw relation record re-verification.

Base Plates

• They are made on the soft tissue areas, therefore are not transferable to different casts of the same arch.

Pressure Indicating Paste vs. Disclosing Wax

Pressure Indicating Paste (PIP)

• Used to adjust complete dentures and partials.• How it is used:

• Paint uniformly on the tissue side of the acrylic.• Spray with Mizzy Spray.

» A silicone emulsion to prevent the PIP from sticking to the tissue.

• Seat the prosthesis intraorally and then remove.

• Areas adjusted using an acrylic bur.• Any burn through created by an undercut or pressure spot.

• Purpose:• To completely seat the prosthesis.• To eliminate sore areas.

Disclosing Wax

• Used to adjust a RPD framework.• How it is used:

• Place on the hard tissue areas of the framework.» i.e. Guide planes, minor connectors, rest seats, and plated

areas.• Place using a wax spatula and Bunsen burner.

• Areas adjusted using a high speed hand piece.• Burn throughs created by pressure areas.

• Purpose:• Accurately adjust the areas that are preventing the

framework from seating completely.

• Other uses:• Aid in seating cast post and cores or crowns and bridges.

Occlude

• Purpose:• Green or white spray used to aid in seating a

prosthesis.» i.e. Crowns, cast post and cores, RPD frameworks.

• Advantage:• Quick and easy to place.

• Disadvantage:• Messy and difficult to clean up.• Material builds up and prevents complete seating

of the prosthesis.

RPD Framework

• Tooth preparation:• All line angles need to be rounded over prior to the

preparation.» Sharp angles can break off when the impression is

separated from the cast. This will prevent the framework from seating completely.

• Look for abrasions on the cast caused by the framework.

• These may be areas that need to be adjusted.

Prefabricated Post vs. Cast Post and Core

Prefabricated Post and Core

• Depends on the amount of remaining tooth structure.

• Should have two opposing walls or 2/3 of the tooth remaining.

• Advantage:• Completed in one appointment.

• Disadvantage:• Over used.• Most posts are flexible.

Cast Post and Core

• Used when there is insufficient tooth structure and adequate root length.

• Ferrule effect:• 3mm is required for retention and resistance.• Most important if the restoration is to be

successful.• If 3mm cannot be achieved than crown lengthening

should be considered or extraction.

Cast Post and Core Preparation

• Full axial reduction is completed prior to the pattern fabrication.

• Need to eliminate thin or unsupported tooth structure.» 1mm minimal thickness.

• E-Z Post:• Used for the canal space only.• Difficult to prep, because it melts.

• G-C Resin Pattern:• Bead brush to build-up the core for good adaptation and

controllability.• Sets too fast to mix and pour and not controllable.

• Preparation should be to ideal axial and occlusal reduction.

• The lab should boast how well you can prep a tooth.

PFM Margin Preparations

• Heavy champfer

• Shoulder

• Shoulder with a bevel

Heavy Champfer

• Axial reduction is 1.2mm-1.5mm.

• Rounded internal line angle.

• Margin designs:• Metal collar.• Collarless margin.• Porcelain butt.

Shoulder

• Axial reduction is 1.2mm-1.5mm.

• Sharp internal line angle.

• Margin designs:• Metal collar.• Collarless margin.• Porcelain butt.

Shoulder Or Heavy Champfer With A Bevel

• Axial reduction is 1.2mm-1.5mm.

• Sharp or rounded internal line angle.

• Margin design:• Metal collar only.

» Width is the same as the bevel.

Cord Packing

• Push the cord into the sulcus at an angle that is opposite to the direction the cord is being placed.

• Prevents pulling the newly placed cord out of the sulcus.

• Place the cord prior to the final margin preparation.

• Displaces the tissue apically and away from the tooth.• Enables the margin to be placed subgingivally with minimal

tissue trauma.

Temporary Crowns

• Good margin and contours are important to maintain healthy gingival tissue.

• Healthy tissue makes impressioning easier.• If the tissue is irritated it may recede when the permanent

crown is placed, exposing the margin or the root surface.

• Why do temporaries break?• Heavy occlusal contacts.• Excursive interferences.• Thin material do to under preparation.• Inadequate diagnostic build up of a tooth with a fractured

cusp(s) or lack of sufficient occlusal height prior to preparation.