Bone Behavior in Relation to the Depth of the Line of Marginal Cementation of Prostheses on Morse Cone Implants: Radiographic Evaluation in a Dog Model.

PURPOSE: This study was aimed at radiographically evaluating the effect of 3 different depths of the cementation line of prosthetic crowns on the bone response around Morse cone implants. MATERIAL AND METHODS: Five dogs underwent extractions of the lower premolars; after 3 months, placement of 30 implants, 3 mm apical to the bone level, was performed. Prefabricated cylinders of alumina, used as abutments, with 3 different transmucosal extension were cemented to the implants with zinc oxide-eugenol cement, determining the depth of the cementation lines (1.5 mm apically, and 0.5 and 2.5 mm coronally, respectively, to the bone level). In the control group, implants and abutments were placed without crowns, therefore, with no cementation line. RESULTS: The results showed no statistically significant differences between the control and test groups regarding the different depths of the cementation line both mesially (P = 0.18) and distally (P = 0.50). CONCLUSION: Different depths of cementation did not affect the behavior of marginal bone, indicating that crowns can be cemented with zinc oxide-eugenol cement at any distance or even at the bone level without disturbing bone healing around Morse cone implants.