Conservative glass ionomer cement occlusal restorations can be as effective as conventional amalgam occlusal restorations

Subjects: The study sample was composed 152 children from 5 primary schools in the Ilala District (one of the districts of the capital city Dar es Salaam, Tanzania) and the mean age at baseline was 11 years. These children were in need of 2 or more restorations on permanent molars. A total of 430 matched contralateral restorations were randomly placed in 152 children, and at the 6-year follow-up, 114 (75%) children were available for evaluation. Key Exposure/Study Factor: The primary study factor was the comparison of the success at 6 years of an amalgam occlusal restoration (the conventional technique carried out in a dental school setting), a low-viscosity glass ionomer cement occlusal restoration (the modified-conventional technique carried out in a portable dental clinic setting), and a low-viscosity glass ionomer cement occlusal restoration (the ultraconservative "ART" approach placed in a field setting). Main Outcome Measure: The main outcome measure was failure of the 3 restorative methods/materials at 6 years, evaluations being completed by 2 calibrated examiners using a modification of the USPHS-Ryge criteria. ¹ Main Results: The principal findings at 6 years were 75% success with conventional occlusal amalgam restorations, 76% success for the modified-conventional lowviscosity glass ionomer cement occlusal restorations, and 69% success for the ultraconservative low-viscosity glass ionomer cement occlusal restorations. There were statistically significant (P > .05) differences in the success rates of the 3 restoration types. The most common causes of failures were restoration fracture/poor marginal integrity, which was most common for amalgam restorations, and loss of material, which occurred significantly (P = .003) more in glass ionomer cement restorations. Secondary caries was significantly greater (P = 0.001) with amalgam restorations (16) compared with glass ionomer cement restorations (3). Conclusions: The authors concluded that the 6-year survival of conventional occlusal amalgam restorations placed in a university clinical setting demonstrated nomore success than modified-conventional low-viscosity glass ionomer cement occlusal restorations and ultraconservative low-viscosity glass ionomer cement occlusal restorations.