Human immune system may damage teeth and dental fillings

14 May 2019

A study by researchers at the University of Toronto has determined that "the body’s own defense system could be a major contributor to dental caries and filling failure”. 

Reported in the Dental Tribune, from a study “Human neutrophils degrade methacrylate resin composites and tooth dentin”, published on April 1, 2019, in Volume 88 of Acta Biomaterialia, the study has found evidence that by doing its job, the immune system is inadvertently causing damage to the teeth it is seeking to protect. 

This occurs when the oral bacteria responsible for the decay of dentin triggers a response from the body whereby auto immune cells known as neutrophils enter the tooth via the gingivae at the root, attack the bacteria, causing damage as they act. 

While they are acting as programmed, counterattacks by auto immune cells, which on their own cause no damage to mineralised teeth, can further corrode the teeth already damaged by the bacteria’s acids. 

“Ours is the first basic study to show that neutrophils can break down resin composites and demineralize tooth dentin. This suggests that neutrophils could contribute to tooth decay and recurrent caries," said Russel Gitalis, a master’s student at the university and first author of the paper. 

Besides providing evidence that the immune system may be part of the process that causes tooth decay and destabilises fillings, the study also opens the door to further important research. 

“We can develop new methods to prevent immune-mediated destruction of teeth,” said co-author Prof. Michael Glogauer, from the Faculty of Dentistry at the university. 

For more on this study, go to “Human immune system contributes to dental caries and damage to dental fillings”