Tunnel restorations: a long-term pilot study over a minimum of five years

Area of Science:

• Restorative Dentistry
• Dental Materials Science
• Clinical Oral Health

Background:

• Tunnel restorations offer a minimally invasive approach to treating posterior tooth decay.
• Glass ionomer and cermet materials are commonly used in conservative dental restorations.
• Long-term clinical data on the performance of tunnel restorations is limited.

Purpose of the Study:

• To evaluate the long-term clinical and radiographic performance of tunnel restorations.
• To compare the longevity of glass ionomer and cermet tunnel restorations against conventional amalgam fillings.
• To identify failure modes and assess the success rates of different restorative materials in tunnel preparations.

Main Methods:

• A prospective study involving 25 patients with 33 tunnel restorations (glass ionomer or cermet) and 14 amalgam control restorations.
• Clinical and radiographic examinations were conducted regularly to assess restoration integrity.
• Failure criteria included recurrent caries, marginal ridge fracture, or significant loss of restorative material.

Main Results:

• All restoration types were satisfactory at the 3-year mark.
• By approximately 5 years, 25% of glass ionomer and 10% of cermet tunnel restorations failed.
• All failed restorations were successfully replaced with amalgam; control restorations remained intact.

Conclusions:

• Tunnel restorations using glass ionomer and cermet materials show moderate success but have a higher failure rate than amalgam.
• Small dental amalgam restorations exhibit greater long-term success and durability in this study.
• Amalgam remains a reliable choice for posterior dental restorations requiring longevity.