Does preservation of the socket decrease marginal bone loss in the mandible after extraction of first molars?

The quality of the bone plays an important part in marginal bone loss (MBL) around dental implants. The aim of this study was to compare MBL around implants the sockets of which had been preserved with the bone around healed sites in the mandible after extraction of first molars. It was a prospective, cohort study in which subjects were divided into three groups (n=30 in each): dental implants were placed six months after preservation of the socket in the first group, eight weeks after tooth extraction in the second, and six months after tooth extraction in the third. The changes between the marginal bone level after loading of the implant and 12, 24, and 36 months later were considered to be the MBL. Age and sex were the variables studied, the condition of the bone (healed socket or preservation) was a predictive factor, and MBL was the outcome. Analysis of variance was used to compare MBL and age among groups. There were no differences in the mean MBL among the three groups 12, 24, and 36 months after loading (p=0.55, p=0.22, p=0.38, respectively). Preservation of the socket did not seem to affect MBL of the first molar of the mandible.