Restorations with extensive dentin/enamel-bonded ceramic coverage. A 5-year follow-up.

The durability of restorations with extensive dentin/enamel-bonded posterior partial and complete ceramic coverages were investigated. The effect of luting with a dual-cured and a self-cured luting agent was also studied. In 110 patients, 182 ceramic coverages (IPS Empress) were placed. In 58 restorations, Syntac was used in combination with the dual-cured resin composite Variolink. In the other restorations luted with the chemically cured resin composite Bisfil 2B, 25 were bonded with Gluma, 57 with Allbond 2, and 42 with Syntac. Of the 182 ceramics, 13 (7.1%) were assessed as non-acceptable after a mean observation period of 4.9 yr (range 4.3 7.5 yr). The reasons for failure were fracture (5), lost restorations (4), secondary caries (3) and endodontic treatment (1). No significant differences in failure rate were seen between the two luting agents or between the three dentin-bonding agents. Ceramic coverages placed on non-vital teeth failed in 9.7% of cases (3/31) and on vital teeth in 6.6% (10/151). The success rate of the dentin-enamel-bonded ceramic coverages reduces the need for a traditional full-coverage therapy and/or post or pin(s) and core placement. The technique investigated showed many clinical advantages such as less destruction of healthy tissue, and avoidance of endodontic treatment and/or deep cervical placement of restoration margins.

Tunnel restorations in permanent teeth. A 7 year follow up study.

The aim of the study was to perform a long-time evaluation of tunnel restorations made in a general dental practice concerning survival time and type of failures. 267 Class I (87%) and II (13%) tunnel restorations in permanent teeth on 193 patients--mostly teenagers and young adults--were evaluated at annual recalls. The observation time-span was 1-7 years. The restoration material was a conventional glass ionomer cement in Class I tunnels and a silver cermet glass ionomer cement in Class II tunnels. The yearly failure rate was 7% and the 50% survival time was 6 years. The reasons for replacement were: marginal ridge fracture (41%), recurrent caries (40%) and cavitation in approximal enamel (19%). No differences in failure rate between Class I and II tunnels could be seen, but recurrent caries was more frequent in Class I tunnels. Restorations made during the second year of the study were more successful, indicating a learning effect. Class I tunnel restorations in general practice can be an alternative to conventional Class II restorations with narrow indications, i.e. patients with relatively low caries activity, small approximal lesions in combination with small demineralization zones in the enamel wall.

Tunnel restorations. A 3 1/2-year follow up study of Class I and II tunnel restorations in permanent and primary teeth.

During 1988-89, 224 patients with approximal caries in the premolar/molar regions were provided with 318 tunnel restorations. In case of perforation of the enamel in the enamel/dentin border, (23%), complete Class II-tunnel restorations with glass ionomer cement and composite resin were made. In case of "intact" enamel, (77%), partial Class I-tunnel restorations were made. The restorations were controlled at annual routine recalls and the success rate after 3 1/2 years was 74% for permanent teeth, and 10% for primary teeth. Restorations in permanent teeth, made during the second year of the study were successful in 82%, as compared with 62% for restorations made during the first year, indicating a learning effect. Failures in the permanent dentition were due to marginal ridge fracture (35%), cavitation in the approximal enamel (31%), and recurrent caries (38%). Failures in primary teeth were predominantly due to marginal ridge fractures (84%). A comparison with the longevity of conventional Class II restorations is made and the possible advantages of the present method are presented.

[Tunnel preparations. Traditional and alternative methods]. / Tunnelpreparationer. Traditionella och alternativa metoder.

Alternative, conservative techniques for treatment of initial approximal carious lesions in the premolar-molar region are described. Beside the "traditional" tunnel preparation a modified technique is described, in which the proximal enamel wall is left untouched, unless the carious lesion has perforated the amelodentinal junction. The internal Class I-cavity is filled with a radiopaque glass ionomer cement and a composite resin. During 2 years 282 approximal surfaces have been treated and in the 1-year follow-up study is shown that both techniques have sufficient success rate to encourage further use and study. The advantages of these techniques compared to Class II-restorations with amalgam or composite resins are discussed and judged as considerable.