Relationship between bite force, bruxism, and fractures of teeth and dental restorations.

The aim of this long-term follow-up study was to investigate the relationship between bite force, bruxism, and fractures of teeth and veneer porcelain of fixed dental prostheses. Patients previously assessed as probable bruxers (n = 30) and non-bruxers (n = 21), all rehabilitated with dental implant-supported restorations, underwent a clinical examination and measurement of maximum bite force. A univariate general linear model was used to compare regression lines showing the relationship between fractures and bite force. Bruxers had significantly higher maximum bite force (p = 0.023) and higher proportion of tooth/veneer porcelain fractures per total number of tooth/prosthetic units (p = 0.045). There was no significant difference in the relationship between frequency of tooth/veneer porcelain fractures and maximum bite force between probable bruxers and non-bruxers (p = 0.054). However, there was a significant difference between probable bruxers and non-bruxers when the percentage of fractures in relation to the total number of units was considered instead of the frequency of fractures (p = 0.035). Higher maximum bite force in probable bruxers was related to higher prevalence of fractures of teeth and veneer porcelain, emphasizing the potential benefits of pre-treatment assessment of bruxism as well as bite force. Easy-to-use reliable clinical methods for bite force measurement should be tested and implemented in dental practice.