Background: Previous studies have shown conflicting results as to whether low bone mineral density (BMD) is associated with severe clinical attachment loss (AL). The effect of dental restoration on AL was not considered in most studies. In addition, studies of this association in Japanese individuals are limited. The aim of this crosssectional study is to evaluate the possible association between BMD and AL with dental restoration information in Japanese community-dwelling postmenopausal females. Methods: The participants were 397 females (average age: 68.2 years). BMDs of the lumbar spine and right proximal femur were measured by the dual-energy x-ray absorptiometry method. Based on lower BMD/young adult mean (YAM) among the two sites measured, participants were classified into three groups: 1) normal: BMD = 80% YAM or higher (n = 161)
2) osteopenia: BMD = 70% to 80% YAM (n = 136)
and 3) osteoporosis: BMD = &lt
70% YAM (n = 100). Multivariable analyses of the differences in AL values among three BMD groups was conducted using general linear models. Adjustments for the percentage of teeth restored and other covariates were considered. Results: Individuals with osteopenia had significantly higher average AL than individuals with normal BMD (P = 0.022). Additionally, the osteoporosis group displayed significantly higher average AL (P = 0.003) and higher percentages of sites with AL ≥4 mm (P = 0.007). Conclusion: The results of the present study indicate that low systemic BMD was associated with severe AL in Japanese community-dwelling postmenopausal females.