Pontics Design in Fixed Partial Denture

Pontics Design in Fixed Partial Denture

Name the component parts of a bridge. Define and classify pontics. Add a note on the selection of pontic design in anterior and posterior teeth. What are the requirements of a pontic?

Parts of a Bridge

• Retainers – Are attached to the prepared abutments
• Connectors – Pontic is connected to the retainer by a connector
• Pontic – Artificial tooth suspended from the abutment tooth.

Read And Learn More: Fixed Partial Denture Short Essay Question And Answers

Pontic Definition

An artificial tooth in a fixed partial denture that replaces a missing natural tooth, restores its function and usually fills the space previously occupied by the clinical crown (GPT).

Pontic  Classification

• According to the shape of the surface contacting the ridge.
• According to the material used in the construction of the pontic.
• According to the type of fabrication.
• According to mucosal-contacting or non-mucosal-contacting.

According to the shape of the surface contacting the ridge

• Spheroidal/Egg shaped/Bullet shaped.
• Conical.
• Saddle.
• Modified ridge lap.
• Sanitary/Hygienic.
• Modified sanitary.

According to the material used in the construction of pontic

• Metal pontics.
• Metal–ceramic pontics.
• Aluminous core-porcelains.
• Resin-veneered porcelain.

According to the type of fabrication:

• Prefabricated:
  • Trupontic
  • Pin facing
  • Interchangeable
  • Modified pin facing
  • Reverse pin facing
  • Harmony facing.
• Custom made.

According to mucosal-contacting or non-mucosal-contacting

• Mucosal contacting:
  • Saddle
  • Modified saddle
  • Ridge lap
  • Modified ridge lap
  • Conical
  • Ovate.
• Nonmucosal contacting
  • Sanitary/hygienic/peril
  • Modified sanitary.
• According to the materials used
  • All metal
  • Metal porcelain
  • Resin/facings.

Requirements of A Pontic

• To provide good esthetics
• To restore function
• Should preserve the residual ridge
• Should be biocompatible
• Should be comfortable for the patient
• Should be able to maintain good oral hygiene
• It should stabilize adjacent and opposing teeth.

Pontic Design

Saddle/Ridge lap design

Saddle/Ridge Lap Design Definition

A ridge lap is one in which contact extends beyond the midline of the edentulous ridge or that forms a sharp angle at the lingo gingival aspect of the tissue contact. It forms a large concave contact with the ridge obliterating the facial, lingual, and proximal embrasures.

Pontic Design Disadvantages

• Difficult to maintain oral hygiene
• Can cause tissue inflammation.

Modified ridge lap

Lingual surface: Slight deflective contour.

Facial surface: Slight faciolingual concavity.

Ridge contact: Only on the crest of the ridge facially (the contacting area of the pontic is convex).

Used: In maxillary and mandibular esthetic zone areas.

Hygienic pontic

No contact with ridge, easily cleansable.

Uses

• Mandibular molar and nonesthetic zones.

Design

• Occlusogingival thickness should be a minimum of 3 mm and with space between the pontic and ridge for easy cleaning
• It is an all-convex design mesiodistally and faciolingually (Fish-belly design).

Design

• Concave mesiodistally and convex faciolingually (hyperbolic paraboloid design). If in the esthetic zone, the visible area is veneered with porcelain.
• Spheroidal/Egg-shaped/Bullet-shaped pontic

Design

• This pontic is convex from all directions with only one point of contact at the center of the ridge.

Use

• Mandibular posterior tooth.

Design

• This pontic is convex from all directions with the only point of contact on the buccal surfaces.

Use

• Mandibular posterior tooth.

Design

• Rounded and cleansable with a small tip.

Use

• In the nonesthetic zone in thin mandibular ridges.
• Ovate pontic: Term coined by Dewey and Zugsmith in 1933.

Definition

• A pontic that is shaped on its tissue surface like an egg in two dimensions, partially submerged in a surgically prepared soft tissue depression to enhance the illusion that a natural tooth is emerging from gingival tissues (GPT).

Design

• The round tissue contacting area is set into the concavity of the ridge.

Pontic Indications

• For the esthetic zone, immediately after extraction (temporary)
• In broad flat ridges that are surgically prepared.
• Coined by Liu in 2003
• The modification includes moving the height of the contour at the tissue surface from the center of the base more labially.

Pontic Advantages

• More esthetic
• Ease of cleaning
• Effective air seal
• Minimizes black triangle
• Little or no ridge augmentation.

Prefabricated pontics

Trupontic

• Was widely used earlier.

Design

• The facing consists of a horizontal tubular slot, which runs from the center to the lingual aspect. This slot along with wide proximal bevels provides retention for the facing.

Prefabricated pontics Disadvantage

• In the case of less occlusogingival, height fabrication of facing is difficult.

Interchangeable Facing

Design

Consists of a vertical slot running down the flat lingual surface, which is retained by a lug that engages the retention slot.

January Pontic

Design

• It is a rounded blunt porcelain with a slot running out to one side, which is oriented towards the lingual during the fabrication of the pontic
• After it is ground to fit into the edentulous space it is reglazed.

Harmony Facing

Design

This facing consists of an un-contoured porcelain gingival surface and two retentive pins.

Harmony Facing Indication

For maximum esthetics in the anterior tooth.

Modified Pin Facing

This facing is made by adding porcelain to the lingual gingival area of a pin facing.

Harmony Reverse Pin Facing

Design

• Porcelain denture teeth modified as pontic facings
• Multiple pinholes 2 mm deep are made with a drill press in the lingual surface of reverse pin-facing
• The pins come out of the backing providing retention.

Harmony Reverse Pin Facing Indication

Deep overbite situations.

Pontic Selection

Factors determining pontic selection

• Type of retainers
• Esthetics
• Occlusal gingival height
• Mesiodistal width of the edentulous area
• Ridge resorption and contour.

Type of retainers

Depending on the type of retainer used, the selection of pontic varies.

• In the case of porcelain-bonded-to-metal retainers, the same type of pontics is used
• If partial veneer retainers are used, prefabricated facings with the same metal as for the retainer are used
• In the maxillary anterior and posteriors and mandibular anterior – Modified ridge lap is the pontic of choice
• In the mandibular posterior region – Spheroidal or hygienic pontic is preferred.

Esthetics

For maxillary anterior tooth modified ridge lap is the design of choice. Depending on the location of pontic placement, the selection of pontic varies.

Occlusogingival height and mesiodistal width

The amount of space available for a pontic alters the choice of design. When there is limited space for a pontic an acrylic pontic with facing is the choice.

Ridge resorption and contour

Classification of ridge deformity (Siebert)

Class 1 Less faciolingual width, normal apicocoronal height.

Class 2 Decreased ridge height with normal faciolingual width.

Class 3 Loss of ridge height and width.

• Class 1 defects can be corrected by subepithelial or submucosal connective tissue grafts
• Class 2 defects and Class 3 defects can be corrected by onlay grafts
• If there is severe bone resorption, placement of fixed restoration will hamper esthetics
• In such cases, surgical ridge augmentation is done or a roll of soft tissue is created labial to the pontic site.