Dental Restorative Procedures Quiz

Checking and Verification of Fixed Prostheses

• The completed restoration is cleaned and disinfected.
• The temporary restoration is removed.
• Remaining cement is removed from the prepared tooth surface using an explorer.
• The preparation is rinsed with water and air spray, then inspected after drying.

Evaluation of Fixed Prostheses

• Seating (proximal contact): The restoration should seat with minimal friction and a gentle occluding force.
• Marginal integrity: The restoration should fit without binding against the occlusal or axial walls.
• Retention and stability: The restoration should have adequate properties to stay in place by friction during initial seating. A bridge's stability can be checked by applying gentle pressure to one retainer verifying the other retainer does not noticeably rock or rotate.
• Occlusion: Evaluate the presence and absence of occlusal contacts using a mylar shim stock and articulating paper to identify high spots. Examine both centric and eccentric contacts (lateral and protrusive). Any issues should be adjusted.
• Contour alignment and occlusal anatomy: The contour of the restoration needs to be compared with adjacent and opposite teeth. This will ensure harmony in appearance and function.
• Contour of the pontic and its relation to the alveolar ridge mucosa: The pontic shape prevents the mucosa from becoming irritated or inflamed by excessive pressure. The contact area should allow for easy self-cleansing.
• Connectors: Rigid connectors should meet the correct interproximal relationship for strength. Non rigid connectors must have the proper retentive qualities.
• Aesthetics: The restoration must match the form, size, surface character, and color of adjacent natural teeth.
• Radiographic checking: X-rays are used to verify the adaptation of the gingival tissue or if there are any undetected open margins.

Seating (Proximal Contacts)

• The restoration should seat with minimal frictional resistance.
• A gentle occluding force should be sufficient to complete seating.

Causes of Incomplete Seating

• Excessive proximal contact
• Nodules on the restoration's fitting surface
• Overextension of the gingival margin
• Tight cast
• Faulty assembling and soldering
• Lack of parallelism of abutment teeth

Excessive Tightness

• All-metal restorations: If tight, adjustment is possible using a rubber wheel. Identify binding points from a satin finish where a shiny spot will show where adjustment is necessary. Quick drying marking liquid or pressure indicating paste can be used to detect areas of excessive contact.
• Ceramic restorations: The contact area can be identified with a red pencil or thin marking tape. A tight proximal contact in unglazed ceramic can be adjusted with a cylindrical stone.

Deficient Proximal Contact

• All-metal restorations: Deficient contacts are usually corrected by soldering.
• Porcelain restorations: Minor corrections can be made with low-fusing "add-on" or correction porcelain.

Presence of Nodules

• Detection: Use a magnifying lens to examine the restoration's surface, particularly the inner angles.
• Causes: Air trapped during investing, inadequate vacuum during investing, improper brush technique, lack of surfactant, and excessive vibration.
• Correction: Small nodules not in critical areas can be removed. Large nodules or those near the margins require remaking the restoration.

Overextension of the Gingival Margin

• Errors in die making or wax pattern carving can lead to overextension of the gingival margins, causing resistance to complete seating.
• Correction: New impressions, dies, and working casts are required.

Tight Cast

• Causes: Improper investment expansion, improper spatulation, improper mold heating, lacking a ring liner, incorrect liquid addition.
• Detection: Paint the restoration's fitting surface with pressure-indicating paste, seat the restoration. Any tight areas will be scratched due to friction.
• Correction: Small interferences can be corrected by spot grinding. Large interfering areas require electro-stripping.

Lack of Parallelism of Abutment Teeth/ Faulty Assembling and Soldering

• Causes: Failure to maintain proper relationship of assembled bridge parts, improper heating of the assembly, incorrect heat application during soldering, improper proximal gap.
• Correction: Disassemble and resolder. Alternatively, use a diamond disk to fracture the joint or melt the solder joint.

Margin Integrity

• The completed restoration should seat passively into place without binding against the occlusal or axial walls of the tooth preparation. Methods used to check for binding include disclosing wax, water-soluble marking agents, and powdered spray.

Elastomeric Detection Pastes

• Similar to silicone impression material.
• Two-paste system.
• Similar viscosity to final luting agents.

Assessment

• Use a sharp explorer that is perpendicular to the marginal area.
• Move the explorer occluso-cervically across the margin. Evaluate for overhanging margins. A slight overhang might be corrected by adjusting the casting, A very small ledge might be acceptable, however it may lead to recurrent decay. An open margin requires a new casting.

Finishing of the Margins

• Subgingival margins: Inability to access in the mouth. Finished on the die, require pre-cementation X-rays.
• Supragingival margins: Finish with the casting seated on the tooth. Use a white stone rotating from the restoration to tooth structure for a proper finish. Burnishing can be done during cementation prior to the cement setting.

Marginal Discrepancy

• Caused by overextended lingual margins: Reduce the overextension from the axial surface preventing it from being underneath the tooth. Reach seating with the axial bulk removed. Adjustment errors lead to a deficient margin.

Retention and Stability

• The restoration should have sufficient retentive properties to stay in place with tenso-frictional grip during initial seating.
• Bridge stability is ensured by placing a finger on one retainer and verifying no rocking or rotation occurs in the other.

Causes of Distortion

• Incorrect wax pattern handling prior to investing
• Underestimating wax relaxation due to induced stress, setting, and hygroscopic expansion.
• Incorrect wax pattern positioning in the casting ring.
• Applying excessive force while removing restoration from casting ring.

Occlusion

• The presence and absence of occlusal contacts are evaluated using mylar shim stock and articulating paper. Check centric and eccentric contacts (lateral, protrusive).
• Occlusal adjustments involving dental porcelain are better done before the finalization of the bisque stage.

Occlusal Assessment

• Select a pair of index teeth as a base for holding shim stock.
• Mark with black articulating foils.
• Mark with red to adjust excursive interferences and deflections.

Alternative Technique for Occlusal Adjustment

• Use an air abrasive unit with aluminum oxide.
• Obtain a matte finish, and check for shiny marks, which suggests areas needing adjustment.
• Disadvantage: Cannot distinguish between centric and excursive contacts, time-consuming, and only applicable to cast metal occlusal surfaces.

Contour, Alignment, and Occlusal Anatomy

• Compare contour and alignment with neighboring and opposing teeth.
• Evaluate cervical contour of the retainers.
• Assess cervical embrasure and interproximal contour.

Contour of Pontic and Alveolar Ridge Mucosa

• (a) The pontic should seat passively in the ridge with a self-cleansing relationship. Pressure should not cause blanching. Pass floss between the pontic and the ridge.
• (b) The pontic should have a correct contour that allows food to sweep over the mucosa (self-cleansing). Stimulating action is needed but avoiding impingement leading to irritation and inflammation.

Connectors

• Rigid connectors ensure proper strength and interproximal relationship.
• Non-rigid connectors are checked for retentive qualities maintaining the corrected interproximal relationship.

Aesthetics

• Fixed restorations should harmonize with adjacent natural teeth in terms of form, size, surface character, and color.
• Evaluate ceramic restorations for contour, surface characterization, and color.

Contour of the Restoration

• Check proximal contact relationships and marginal fit.
• Verify the contour of the gingival third to avoid excessive bulk (P.D. disease).
• Use a thin flexible disc to reduce any overcontoured interproximal areas.

Anterior Teeth Evaluation

• In anterior teeth, 1–2 mm of clinical crown should be visible with the upper lip relaxed.
• Incisal edge of maxillary lateral incisors are 1-2 mm shorter than central incisors.
• Evaluate "negative space", and incisal embrasure presence to ensure a natural appearance.
• Have the patient pronounce the letter "F", with the incisal edges of the maxillary central incisors touching the "wet/dry line" of the lower lip.

Line Angles and Overall Contour

• Mark line angles of porcelain in the bisque stage using a red pencil and comparing with adjacent and contralateral teeth.
• Evaluate overall contour – should match adjacent teeth.
• Saliva moistening reflects light in the same way as glazed restoration.

Surface Characterization

• Thoroughly dry the teeth and examine their surfaces.
• Simulate surface defects with diamond stones.
• Flat/concave surfaces should reflect light producing highlights.
• Avoid over-characterization to prevent unnatural appearance.

Radiographic Checking

• Verify gingival adaptation and ensure no open margins interproximally using radiographic imaging.

Remount Procedure

• Necessary if significant occlusal adjustments are required on multiple restorations.
• A remount procedure helps convey restoration relationships to the lab for further adjustments.
• Advantages include organized occlusion adjustment, and decreased chair time.

Armamentarium

• List of equipment for a remount procedure, including impression trays, irreversible hydrocolloid, rubber bowl and spatula, interim luting agent, petrolatum, photopolymerizing resin, stiff wire, zinc oxide-eugenol occlusal registration paste, inlay wax, reversible hydrocolloid, facebow transfer equipment, and centric relation recording.

Materials for Remount

• The materials used for the remount should be 5mm or less in thickness, fit the cast passively, and have a lubricated casting, occlusal index, and impression material.

Alternative Techniques for Occlusal Adjustment

• Using an air abrasive unit with aluminum oxide: Obtain matte finishes Identify and adjust areas with shiny marks Negative: Not able to differentiate between centric and excursive adjustments, time consuming, limited to cast metal restorations