40 Questions
What is the recommended distance from the incisal or occlusal edge for the margins of a resin-bonded FDP?
1 mm
What is the purpose of making definitive rests and grooves in a resin-bonded FDP?
To enhance resistance form for the retainers
What percentage of the tooth circumference should be prepared for a resin-bonded FDP?
At least 180 degrees
What is the purpose of making an accurate impression in a resin-bonded FDP?
To ensure marginal fit
Why are temporary occlusal stops important in a resin-bonded FDP?
To prevent significant supraocclusion of the abutment teeth
What is the recommended tool for preparing occlusal rest seats and cingulum notches in a resin-bonded FDP?
Diamond or carbide inverted cone bur
What is the recommended tool for preparing gingival margins and circumferential preparation in a resin-bonded FDP?
Chamfer or round-tipped diamond
Why is it important to have small, defined gingival margins in a resin-bonded FDP?
To guide the laboratory as to the gingival extent of the retainer
Why are patient satisfaction with the final result likely to be low if expectations are unrealistic?
Because the patient's expectations do not align with the realistic outcome
Which of the following should be avoided when selecting abutment teeth?
Teeth with active periodontal disease
What is a crucial factor in assessing periodontal support when selecting abutment teeth?
All of the above
Why may the surface area of abutment teeth be compromised?
All of the above
What type of teeth can make particularly good abutments?
Retained deciduous teeth
Why may the roots of retained deciduous teeth be suitable for abutments?
Because they are ankylosed and well-placed to act as abutments
What is crucial to optimise success when planning for RBBs?
A detailed assessment of static and dynamic occlusal relationships
What may affect the degree to which a retainer can be extended?
All of the above
What is the primary goal of restoring missing teeth?
To improve oral function and aesthetics
In which patients may accepting a shortened dental arch be a suitable option?
Older patients with reduced manual dexterity
Why may RBBs be preferable to RPDs in certain patients?
Because they are minimally invasive
What is a disadvantage of RBBs for young patients who have suffered the early loss of an anterior tooth?
They may condemn the patient to years of denture wear
What should be considered when managing patient expectations with regard to RBBs?
Both aesthetic outcome and longevity
Why may RBBs be a suitable option for patients who are apprehensive of dental treatment?
Because they take minimal clinical time and rarely require anaesthetic
What is essential for patients before embarking on fixed prosthodontics with RBBs?
That they are dentally motivated and caries and periodontal disease are under control
What is a characteristic of the preparation for RBBs?
It is limited to enamel and the labial surface remains intact
What is unique about the posterior splint-FDP?
It uses multiple rests and distinct mechanical retention of the abutment.
What is the purpose of surface treatment for bonding in RBB?
To increase the surface area for bonding.
What is a characteristic of the Cast perforated resin-bonded bridge (Rochette bridge)?
It has perforations that weaken the metal retainer.
What is the function of salt crystals in the Virginia bridge?
To sprinkle a uniform monolayer on the surface.
What is a limitation of the Cast mesh pattern (dura lingual)?
It requires a thick cast and is technique sensitive.
What is a characteristic of anterior splint design?
It must engage as much enamel as possible for retention.
What is the advantage of fiber-reinforced RBB?
No advantages are mentioned in the content.
What is the purpose of macro-mechanical retention?
To create a mechanical bond between resin and metal.
What is a disadvantage of using composite resin pontics?
Degradation of composite and loss of pontic
What is the primary advantage of using unidirectional fibres in a composite?
Improves the mechanical properties of a composite in a single direction
What is the purpose of oral health education in resin-bonded bridges?
All of the above
What is the most common technical reason for RBB failure?
Debonding
What type of fibre arrangement is most suitable for constructing long spans?
Unidirectional fibres
What is the primary advantage of using bidirectional fibres in a composite?
Supports stresses multi-directionally
What should patients be warned of when a fixed-fixed design has been used?
The risk of one retainer debonding
What is the primary advantage of using composite resin?
All of the above
Study Notes
Resin Bonded Bridges
- Definition: A single pontic supported by a thin metal retainer placed lingually and proximally on the abutment teeth, with minimal preparation limited to enamel and labial surface remaining intact.
Case Selection
- Patient factors to consider:
- Health and age of the patient
- Patient expectations
- Local factors related to dental health and the missing tooth itself
- Accepting a shortened dental arch in older patients with reduced manual dexterity
- Preferable to a removable partial denture (RPD) in cases with significant periodontal disease or dental caries
- Advantageous for young patients who have suffered early loss of an anterior tooth
- Minimally invasive, requiring minimal clinical time and rarely needing anaesthetic
- Suitable for patients who are apprehensive of dental treatment or unable to commit to more involved treatment
- Importance of managing expectations regarding aesthetic outcome and longevity
Abutment Tooth Selection
- Investigations should be carried out to ensure endodontic and periodontal health
- Periodontal support should be assessed considering bone levels and root configuration
- Abutments with active periodontal disease should be avoided
- Coronally, sufficient enamel should be available for bonding
- Surface area may be compromised if teeth are restored or have significant tooth wear
- Alignment or angulation of teeth may affect the degree to which a retainer can be extended
- Unconventional approaches may be necessary in certain cases
- Deciduous teeth can make good abutments due to their multirooted nature and large coronal surface area
Occlusal Features
- Detailed assessment of both static and dynamic occlusal relationships is crucial for optimal success
- Gingival margins and circumferential preparation can be accomplished with a chamfer or round-tipped diamond
- Occlusal rest seats and cingulum notches can be prepared with a diamond or carbide inverted cone bur
- Retentive features (e.g., slots, grooves) can be made with a tapered fissure bur
- Restoration design should be determined before beginning tooth preparation
- Importance of surveying the abutment teeth and making diagnostic preparations on a cast
Preparation and Bonding
- Step-by-step procedure:
- Leave margins about 1 mm from the incisal or occlusal edge and, if possible, 1 mm from the gingival margin
- Definite rests and grooves provide resistance form for the retainers and assist in positive seating during cementation
- Small, defined gingival margins guide the laboratory as to the gingival extent of the retainer
- Make an accurate impression, as marginal fit is crucial for a resin-bonded restoration
- Provide temporary occlusal stops to avoid supraocclusion of the abutment teeth
Bonding Materials
- Three different materials to use for RBB:
- Metal
- Ceramic
- Fiber reinforced
Surface Treatment for Bonding
- Depends on retainer material
- Surface treatment for metal RBB:
- Mechanical: Macro retention
- Cast perforated resin-bonded bridge (“Rochette bridge”)
- Water soluble salt crystals (Virginia bridge)
- Cast mesh pattern (dura lingual)
Pontic Designs
- Extracted natural teeth
- Acrylic teeth
- Bonded to proximal or lingual surface of abutment by wire or meshwork fixed by composite
- Drawback: degradation of composite and loss of pontic
- Composite resin:
- Restores esthetics and function
- Nonirritating and hygienic
- Can be repaired, modified, or removed
- Fibres can be arranged unidirectionally or bidirectionally to improve mechanical properties
Dealing with Failure
- Biological reasons for failure: caries and periodontal disease
- Technical reasons for failure: debonding
- Importance of oral health education and patient warning regarding debonding
Learn about resin bonded bridges, a type of dental restoration that aims to improve oral function, aesthetics, and occlusal stability. Understand the three phases for predictable success: case selection, preparation of abutment teeth, and bonding.
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