[Ridge stabilization with adhesive inlays in MOD cavities].

Area of Science:

• Biomaterials Science
• Dental Materials
• Biomechanics

Background:

• The structural integrity of posterior teeth is crucial for function.
• Dental restorations aim to restore tooth form and function, but their effect on cusp biomechanics is not fully understood.
• Understanding cusp flexural rigidity is essential for evaluating the long-term stability and performance of various dental restorative materials.

Purpose of the Study:

• To determine the flexural rigidity of buccal cusps of upper premolars.
• To compare the stiffness of cusps restored with different materials (cast gold, composite, ceramic, amalgam) against unrestored teeth.
• To evaluate the effect of thermocycling on the flexural rigidity of restored cusps.

Main Methods:

• Measurement of flexural rigidity of upper premolar buccal cusps under a 100 N vertical load using displacement transducers.
• Comparison of cusp stiffness in teeth restored with cast gold onlays, composite inlays, ceramic inlays (luted with composite resin), and amalgam restorations.
• Assessment of changes in cusp stiffness after thermocycling for composite and ceramic restorations.

Main Results:

• Restorations with cast gold onlays, composite inlays, or ceramic inlays luted with composite resin significantly increased cusp stiffness compared to unrestored teeth.
• Amalgam restorations and cast gold inlays did not result in higher flexural rigidity of the cusps compared to unrestored cavities.
• Thermocycling led to a decrease in cusp stiffness for most teeth restored with composite or ceramic inlays.

Conclusions:

• Certain dental restorations, particularly cast gold onlays and composite/ceramic inlays luted with resin, enhance the flexural rigidity of upper premolar cusps.
• The stability of stiffness in composite and ceramic restorations may be compromised by environmental factors like thermocycling.
• Material selection for cusp restoration should consider not only initial stiffness but also potential degradation under intraoral conditions.