Assessment of marginal degradation of restorations on impressions

Abstract

The study aimed to validate the scoring of the degree of marginal degradation of amalgam restorations by using impressions, as an alternative to other indirect scoring methods using photographs or casts. Ten-year-old condensation silicone elastomer impressions and epoxy replicas made in 1979 were compared in a scanning electron microscope at 5 kV with different magnifications up to x200. The impre~sion material was not distorted or degraded, and the dimensional stability was good after 10 years of storage in a dry environment. The interexaminer agreement of the scorings of impressions and a six-point scale reference set was satisfactory as evaluated by kappa statistics, demonstrating that degrees of marginal degradation can be distinguished on impressions with relatively high accuracy. The rating distribution of the scorings of impressions showed good correlation to the rating distributions obtained with the clinical USPHS rating method and with photographs for recording marginal degradation. A slight difference between the photographic and impression ratings at the upper and lower levels of the six-point rating scale was observed. The difference varied with the type of alloy, possibly due to a bias depending on the surface quality-that is, whether the restoration kept the glossiness of high polishing or became heavily tarnished. 0 Amalgam degradation; clinical rating; clinical study; kappa statistics; silicone elastomer AsbjomJokstad,

Comparison of different methods for evaluating resin composite restorations in posterior teeth

“…In order to detect early deterioration and differences between restorations it would be helpful to have a more discriminative scale (HICKEL et al, 2007) or more objective ranking methods. These include the use of intraoral photography (MAHLER; ENGLE; BRYANT, 1986;SMALES, 1983;SMALES;CREAVEN, 1985;KREULEN et al, 1993a);impressions (KREULEN et al, 1993b;JOKSTAD;MJÖR, 1991); dental cast models (BAYNE et al, 1994;LEINFELDER et al, 1986); stereo microscope (LAMBRECHTS et al, 1984), commercial and customized profilometers (LEINFELDER et al, 1986); computerized three-dimensional measuring microscope (DUPERON; NEVILE; KASLOFF, 1971); three-dimensional laser digitizer (PERRY et al, 2000). The use of dental photographs and cast dental models contributed significantly to a more accurate interpretation.…”

“…Yip and colleagues (YIP et al, 2003) evaluating resin-based composites observed that small discrete marginal discolorations and discrepancies in marginal integrity were detected more readily from the photographs and replicas, respectively, than from the direct clinical examinations. The indirect methods produce a permanent record of the restorations and the raw data is always available for reexamination, change in evaluators or modification in evaluation methods (TÜRKÜN; AKTENER; ATES, 2003;SMALES, 1983;KREULEN et al, 1993a;JOKSTAD;MJÖR, 1991). However, the photographic recording and the replica method are not optimal in field trials since these techniques are time-consuming.…”