Study Finds No Significant Link Between Dental Fractures and Amalgam Restorations

Led by Luana Dos Santos Souza from the Universidade Estadual Paulista, Instituto de Ciência e Tecnologia, Departamento de Odontologia Restauradora, São José dos Campos, São Paulo, the study explored whether amalgam restorations increased the risk of dental fractures and assessed the influence of factors such as restoration size and wear facets.

The investigation involved 25 patients with fractured teeth restored with amalgam (case group) and 50 patients with non-fractured teeth, either untreated or restored with amalgam, composite resin, or other materials (control group). Researchers evaluated variables such as the type and extent of restorations, the remaining tooth structure, and the presence of wear facets.

Alginate impressions of the teeth were taken to create plaster models, which were then assessed by two calibrated examiners using digital calipers to measure the size and extent of fractures or restorations. Statistical analyses, including the Chi-square test and odds ratio calculations, were used to identify any significant associations.

Key Findings:

• No statistically significant difference was observed in the risk of fractures between teeth restored with silver amalgam and those restored with other materials.

• Fractures larger than 3.5 mm showed a fracture risk of 0.53 for amalgam restorations, but without statistical significance.

• The presence of wear facets did not notably increase fracture risk in amalgam-restored teeth, with an odds ratio of 1.357.

Based on the results, the researchers concluded that silver amalgam restorations do not significantly contribute to the likelihood of dental fractures. These findings provide important evidence against the belief that amalgam restorations elevate the risk of tooth failure.

"The study suggests that, under its specific conditions, there is no clear association between dental fractures and the presence of silver amalgam restorations," the authors wrote. 

The study contributes valuable insights to the ongoing discussion around the safety and performance of amalgam restorations. While supporting their continued use, the authors highlight the need for further research to evaluate other factors affecting restoration longevity across diverse clinical settings and patient populations.