Dental Techniques: Bottom Net Use

Labial Veneers

• Indications: Diastema, discolored teeth, malaligned teeth, peg-lateral shape, malformed teeth, tooth wear, inadequate enamel, large restorations, teeth needing major color change, teeth with little remaining coronal structure.
• Advantages: Excellent esthetics, color stability, favorable response to light, exceptional marginal integrity, inherent strength, durability, conservation, insoluble.
• Disadvantages: Expensive, fragile, difficult to repair, difficulty in shade matching, time-consuming, technique-sensitive.

Fixed Partial Denture (FPD)

• Definition: Prosthesis replacing one or more missing teeth on one arch, permanently cemented or attached, supported by natural teeth.
• Indications: Anterior missing tooth, short span edentulous space, handicapped innervation, splint after periodontal treatment, sound abutments.
• Contraindications: Long span edentulous space, free-end situations, periodontal disease, poor abutment condition.
• Components: Connectors, abutments, pontic(s), terminal abutments.
• Factors Influencing FPD Design: Abutment viability, degree of mutilation, pericrematal area/crown length, bone configuration, crown to root ratio, axial alignment, periodontal health, furcation involvement, tooth mobility, Ante's Law (combined pericemental area of all abutments must equal or exceed that of the replaced tooth(s)).
• Types: Cantilever FPD, Roundhouse FPD, terminal.
• Retainer Types: Extracoronal (fill), partial veneer, intracoronal, radicular.
• Connector Types: Rigid (casted, soldered, loop), non-rigid (dovetail, split pontic).
• Pontic Types: Ridge lap, modified ridge lap, lap facing, banding, conical, ovate, bar sanitary, modified sanitary, fish belly.

Shade Selection

• Shade Guide: Match the shade guide to the brand of porcelain used.
• Guidelines: Select shade after prep, match under various light types to overcome metamerism, at different angles, patient upright, operator positioned between patient and light source, clean adjacent teeth, keep natural teeth wet when selecting, choose lighter shade if in doubt.
• Color Dimensions: Hue, chroma (saturation), value (lightness/darkness).
• Verification: Initially dry, verify wet.

Gingival Management

• Purpose: Expose cervical finishing line for detailed impression, restore subgingival caries, prepare for cementation of restorations.
• Methods:

  • Mechanical: Physically displacing gingiva with modelling compound & copper bands. (Disused)

  • Mechanico-mechanical: Using retraction cord (twisted, braded, knitted) impregnated with chemicals. Chemicals shrink gingiva, exposing cervical area. (Most Common)

    • cord sizes: #000 (superfine), #00 (ultrafine), #0 (fine), #1 (regular), #2 (wide), #3 (ultra wide)
    • Chemical Content: 8% Racemic epinephrine, Alum (Aluminum Potassium Sulfate), Aluminum Chloride, Aluminum Sulfate

  • Chemical: Use chemicals alone injected into sulcus. (Traxodent, Expasyl). Easier to control than mechanico-chemical.

  • Surgical: (Rotary Curettage, Electrosurgery, Laser Troughing). Involves cutting gingival tissue to expose the CFL.

  • Factors to consider: Time elements, manipulation procedure, safety (patient medical history), cost.

PFM Fabrication

• Procedure: Starts with diagnosis and treatment planning, follows with mock preparation, temporary crown fabrication (direct or indirect), final impression, shade selection, anesthetic application, tooth preparation, gingival management, die construction and mounting, job order writing, metal coping/frame fabrication (wax pattern, spruing, investing, wax elimination, casting, removal from ring, trimming, electropolishing, sand blasting/air abrasion, pickling), temporary crown removal, shade verification, trial metal coping, application of dentin conditioner, re-cementation of temporary crown, porcelain build-up, baking, trimming, removal of temporary crown, trial unglazed, trial glazed, final cementation.
• Materials: Various impression materials including rubber, alginate, temporary cements, final cement options like zinc phosphate, zinc polycarboxylate, resin ionomer, and adhesive resin cements are discussed.
• Important considerations: Technique for cementation, avoiding premature occlusion, pulpitis, or loosening, and recurrence. Specific instructions for creating job orders.
• Recall Procedures: 24-hour post-delivery recall, 6-month recall, and as-needed recall for patient problems.

This quiz focuses on the use of bottom nets in terminal abutments with questionable prognoses. Explore the implications of prognosis on the decision-making process regarding corrective measures. Test your understanding of dental practices related to abutment treatment.