Marginal ridge strength of Class II tunnel restorations

Area of Science:

• Restorative Dentistry
• Biomaterials Science
• Dental Mechanics

Background:

• Dental cavity preparations aim to restore tooth structure and function.
• Traditional Class II box preparations are widely used for posterior teeth.
• Minimally invasive techniques, like tunnel preparations, are gaining attention.

Purpose of the Study:

• To compare the marginal ridge strength of tunnel preparations versus traditional Class II box preparations.
• To evaluate the influence of composite and glass ionomer (GI) restorative materials on this strength.

Main Methods:

• Eighty-four extracted maxillary molars were divided into six groups.
• Preparations included tunnel and traditional Class II designs.
• Restorations utilized composite or GI materials; controls included whole teeth and unrestored teeth.
• Marginal ridge strength was assessed via compressive loading until fracture.

Main Results:

• Whole teeth exhibited the highest strength, significantly greater than all prepared groups.
• Traditional Class II preparations restored with composite showed higher strength than tunnel preparations with composite.
• Tunnel preparations restored with GI showed comparable strength to traditional Class II preparations with composite.

Conclusions:

• Traditional Class II preparations may offer superior marginal ridge strength compared to tunnel preparations when restored with composite.
• Glass ionomer restorations in tunnel preparations may provide comparable strength to composite in traditional Class II preparations.
• Further research is needed to optimize tunnel preparation designs and material selection for enhanced durability.