Tunnel Restorations: A Review

Abstract

Conventional cavity designs are coming under increased scrutiny because of an increased emphasis on preservation of tooth substance. The tunnel restoration, when used with glass ionomer, may overcome some of the disadvantages of conventional cavity preparations. Justification for the use of the tunnel restoration is from a limited number of short‐term clinical observations and destructive laboratory testing of marginal ridge strength. The technique is not without shortcomings. Long‐term clinical and nondestructive laboratory trials examining the strength of teeth with tunnel restorations should be undertaken prior to its acceptance as a replacement for techniques in which the marginal ridge is removed.

A 3‐year clinical study of tunnel restorations

“…The tunnel preparation technique is a more conservative approach to the approximal lesion than Black's classic principles. Carious tissue is removed via the occlusal surface through a tunnel (1)(2)(3)(4)(5). Glass polyalkenoate (ionomer) cement, particularly the cermet type, is the material most often used for restoration (5,6).…”

“…Carious tissue is removed via the occlusal surface through a tunnel (1)(2)(3)(4)(5). Glass polyalkenoate (ionomer) cement, particularly the cermet type, is the material most often used for restoration (5,6). Unless the approximal surface is cavitated, it is not recommended to break through the demineralized enamel wall during preparation, since fluoride leaching from the cement may contribute to remineralization (7,8).…”

“…Several advantages with this technique compared to the traditional class II preparation have been suggested: preservation of tooth substance; reduced microleakage and plaque retention; improved esthetics; biocompatible restorations; fluoride effect of glass polyalkenoate (ionomer) cement on adjacent tooth structure and adjacent teeth, and time efficiency (5,8). The main objections to the tunnel technique, however, are difficulties in ensuring complete caries removal due to the limited accessibility (9)(10)(11), and collapse of the marginal ridge (12).…”

The tunnel restoration

“…In the 1980s the preparation was re-introduced by Hunt 2 and Knight 3,4 and advocated as a more conservative procedure than a conventional Class II cavity, for the treatment of primary approximal caries in posterior teeth. [5][6][7][8] Glass ionomer cements, introduced by Wilson and Kent in the early 1970s, 9 have been described as the materials of choice for the restoration of tunnel preparations. [10][11][12][13][14] These materials will bond to enamel and dentine and leach fluoride.…”

A Clinical and Microbiological Study of Approximal Carious Lesions

“…approximal caries in permanent posterior teeth [Hunt, 1984;Knight, 1984aKnight, , 1984bHowe, 1989;Hunter and Hunter, 1989;Hunt, 1990;Papa et al, 1992]. During tunnel preparation access to the approximal caries is made via the occlusal surface leaving the marginal ridge intact.…”