Fluorides leaching from restorative materials and the effect on adjacent teeth.

OBJECTIVE: Placing a Class II restoration in a tooth changes the local environment, including that for the adjacent tooth. Apart from the change to a less- or non-cariogenic environment for the restored tooth, the effect of leachable components from a restoration in the adjacent tooth should be taken into consideration. METHOD: Practice-based clinical studies comprising of 1341 unrestored proximal surfaces in contact with Class II restorations using different restorative materials were reviewed to assess the effect on the caries development on the adjacent teeth. The caries status of the adjacent un-restored proximal surface was assessed as being clinically sound, having active caries with or without cavitation, or having arrested caries. Restorations from nine clinicians were reviewed. They had attended annual meetings where all aspects of the investigation had been discussed. The surfaces were followed for up to eight years. RESULTS: A reduced rate of caries development and progression were found on surfaces in contact with fluoride releasing materials like glass ionomers, resin modified glass ionomers and compomers compared to surfaces in contact with amalgam. CONCLUSION: Fluoride releasing materials reduce the development and progression of primary caries on adjacent proximal surfaces.

The longevity of different restorations in primary teeth.

BACKGROUND AND AIM: This paper reviews three published papers and adds results from a fourth study which aimed to determine which restorative material would be the best alternative(s) to amalgam (AM) in primary teeth. DESIGN: All studies had a practice-based design and were part of the routine treatment of children and adolescents. The clinicians were assigned which materials to use in a randomised matter in the first three studies which lasted for 7-8 years. In the fourth study conducted 4 years after the initial studies, the clinicians were free to select the restorative materials. RESULTS AND CONCLUSIONS: Resin modified glass ionomer (RMGI) and compomer (COM) restorations showed similar longevity compared with AM, whereas conventional GI restorations showed significantly shorter longevity. The studies indicated that the 'new and improved' materials based on in vitro tests did not always show enhanced clinical properties. In the last study, where clinicians freely selected the restorative materials they used in their practices, seven used COM, one used conventional GI materials and one used a combination of the two types of material.

Eight-year study on conventional glass ionomer and amalgam restorations in primary teeth.

The aim of this randomized clinical study was to compare the longevity and the cariostatic effects of conventional glass ionomer and amalgam restorations in primary teeth placed in everyday practice in the Danish Public Dental Health Service. All restorations inserted during a 7-month period by 14 clinicians in 2 municipalities were included in the study. The sample consisted of 515 conventional glass ionomer restorations and 543 amalgam restorations in 666 children aged between 2.8 and 13.5 years. The restorations were in contact with 592 unrestored surfaces in primary and permanent teeth. The study was terminated after 8 years, with 2% of the restorations in function and 7% patient dropouts. Fifty percent of the teeth restored with glass ionomer and 63% of those with amalgam were exfoliated with the restoration in situ, while 42% of the glass ionomer and 20% of the amalgam restorations had been repaired or replaced. Fracture of restoration, endodontic complication, and loss of retention were the major reasons for failure. The 50% survival time for glass ionomer restorations in all cavity types was 42 months, while the median survival time for amalgam restorations could not be estimated but exceeded 7.8 years (P < 0.001). Progression of caries lesions on tooth surfaces adjacent to amalgam restorations required operative treatment on 30% of the teeth, while only on 16% of teeth adjacent to glass ionomer restorations. The 75% survival time was 40 months for surfaces in contact with glass ionomer compared to 25 months for surfaces in contact with amalgam (P = 0.005). Multivariate analyses were performed in order to assess the influence of a number of factors on the longevity of restorations, occurrence of prevalent failures, and caries treatment of surfaces in contact with the restorations. Owing to the high frequency of failures of the conventional glass ionomer restorations, it was concluded that they are not an appropriate, universal alternative to amalgam for restorations in primary teeth, although they reduce caries progression and the need for operative treatment of adjacent surfaces.