Complete Dentures Quiz

Single Complete Dentures

• Single complete dentures are a treatment for cases where only one jaw is restored with a full prosthesis.
• Maxilla (upper jaw) is more frequently treated with this method.
• Opposite Jaw Dentition:
  • A complete arch with enough natural teeth and fixed restorations, requiring no additional prosthesis.
  • A partially-dentate arch where missing teeth are replaced with removable, fixed partial, or implant-supported fixed prostheses,
  • Mucosa-supported, tooth-supported or implant-supported full dentures.
• Complete dentures should restore lost function and aesthetics, maintaining the remaining tissues.
• Success depends on stability, retention, and support.
• In constructing both upper and lower complete dentures, teeth are aligned for a balanced occlusion.
• A single denture is usually more complex than when both jaws are restored simultaneously, as balancing occlusion with natural teeth is difficult.
• Tooth loss can cause bending, elongation, and rotation of remaining teeth, making occlusion difficult to stabilize.
• The inability to balance occlusion is the primary factor that reduces the success of single complete dentures.
• Issues must be evaluated during treatment planning
• If the fabrication of the prosthesis fails to overcome these problems, horizontal forces on the opposing jaw, exceeding physiological limits, can result in traumatic occlusion.
• Maxillary single complete dentures tend to be more successful than mandibular due to a larger chewing pressure area in the maxilla.
• Mandibular dentures are more difficult due to greater mobility.

Problems Encountered

• Lack of Stability
• Damage to mucosa and resorption of alveolar bone
• Unsatisfactory function
• Fractures in the denture base
• Wear on artificial/natural teeth, depending on material

Midline Fractures

• More common in maxillary total dentures.
• Often due to lack of relief in the median palatine suture region.
• Failure to achieve occlusal harmony (inappropriate contact points, positioning of teeth outside ridges, focal concentration of occlusal contacts, thin acrylic base).

Alveolar Bone Resorption

• Severe bone resorption is a major factor limiting success of single complete dentures.
• Preserving the continuity and integrity of remaining tissues is crucial.

Patient Examination

• Examination of the edentulous jaw arch
• Examination of the opposing jaw arch
• Features of the denture base (thickness, structure of mucosa)
• Occlusion
• Types of artificial teeth

Examination of Edentulous Jaw Arch

• Resorption degree and shape of the alveolar arch
• Address uneven/sharp crests (sores, pain)
• Consider using soft lining materials if surgery is not an option.
• Thickness and structure of the mucosa (should be 1.5mm ideally)
• Address toruses (small ones can be tolerated; large ones should be surgically removed).

Occlusal Surfaces of Teeth

• Natural teeth with high cusps: low chewing force, little eccentric movement.
• Worn teeth: high chewing force, excessive eccentric movement.
• Reduce the slope of teeth with high tubercle inclination.

Occlusal Surfaces of Teeth (cont.)

• Presence of excessively worn opposing teeth can affect denture stability
• Worn teeth cause buccolingual distance increase, thus requiring occlusal surface restoration to previous functional width (buccal and lingual surfaces must be abraded first)

Inter-occlusal Relations of Teeth

• Posterior teeth that align outside the crest create harmful forces.
• Centrally aligning maxillary teeth with lingual cusps of mandibular teeth and inclined buccal cusps can improve stability.

Features of Denture Base

• Must be within physiological tolerance and cover largest possible area.
• Address toruses/bony prominences through relief if they cannot be surgically removed.
• Sof lining can address knife-edge crests, protruding anatomical structures.

Occlusion

• Incorrect placement of teeth causes denture fractures.
• Bilateral balance occlusion is important during eccentric movements so there are no premature contacts in the posterior teeth.

Occlusion (cont.)

• Opposing arch morphology should be considered in tooth selection.
• Select teeth with appropriate tubercle inclination
• Shallow surfaces and point contacts are preferable over deep overbites
• Contact between anterior teeth should be avoided to prevent rotation of the denture

Combination Syndrome

• Excessive load concentrated in the maxillo-anterior region can cause bone loss, overgrowth of tubercles, hyperplasia of palatal mucosa, and elongation of lower teeth.
• Can occur in cases with upper-total, lower Kennedy 1 cases.

Prevention

• Anterior teeth should not touch each other.
• Use high-quality acrylic teeth instead of porcelain in upper and lower edentulous Kennedy cases
• Routine check-ups every six months.
• Surgical removal of fibrous tissue if there's sufficient underlying bone
• Surgical removal of fibrous tissue if there's enough underlying bone

Types of Teeth

• Acrylic teeth are mostly used (resist forces, reduce resorption)
• Porcelain teeth are wear-resistant but do not form chemical bonds with the base, and can wear the opposing natural teeth

Occlusally Reinforced Teeth

• Amalgam applied to the occlusal surfaces of artificial teeth improves wear prevention

Strategies/Methods

• Use new generation acrylic/composite resin denture teeth.
• Periodic examinations are useful.
• Important to consider the occlusion plane of the existing single denture

Examination of opposing Natural Teeth

• Malpositioned teeth can cause cusp conflicts with artificial teeth, leading to the denture tipping.
• The lower and upper teeth should ideally be in the same horizontal plane (parallel)

Procedures to resolve occlusion / alignment issues

• Teeth can be abraded and Irregularities can be corrected at the enamel level only.
• Natural teeth may be replaced with crowns, inlays, or onlays.
• Orthodontic treatments can be employed
• Extraction of problematic teeth may be an option.

Analysis

• Reported by Yurtstas (1962), based on Monson's Galot Theory (combining Spee and Wilson curves).

Class III Cases

• Difficulties with denture fabrication due to underdeveloped maxilla and a narrow attachment area.
• Could experience negative effects on denture stability.
• Alignment difficulties can result in pain at the crest of the ridge/lips.

Mandibular Total Denture

• Irregularities in the opposing arch should be addressed.
• Ensuring balanced occlusion is essential.
• To distribute forces evenly, the prosthesis should be spread as widely as possible.

Removable Full Denture against Fixed Partial Prosthesis

• First steps for maxilla: anatomical size, functional impression, vertical dimension detection, appropriate preparation, metal try-in, finishing, final occlusal alignment.

Single Complete Denture Considerations

• Easier and more reliable to make both dentures at the same time rather than making one over an existing one.

Conditions for new opposing Single Complete Denture

• Well aligned teeth on the crest of the ridge for proper stability and better chewing efficiency
• Ideally, aesthetics appropriate
• Sufficient tissue support
• Suitable cusp heights
• Properly sized denture base supporting surrounding tissues
• Good stabilization and retention of the denture

Conclusion

• Proper occlusal plane alignment is crucial in single complete denture construction.
• Pre prosthetic mouth preparation is necessary.
• Select appropriate denture base, materials, and teeth.
• Regular checkups are important.
• Consider implant-supported options if other methods fail.