Effects of Surface Treatment Modification and Implant Design in Implants Placed Crestal and Subcrestally Applying Delayed Loading Protocol.

OBJECTIVES: The aim of this study is to evaluate the effect of the surface modification and cervical implant design on the bone remodeling in implants installed at the crestal and subcrestal bone level. METHODS: Ten American Fox Hound of approximately 1 year of age, each weighing approximately 14 to 15 kg, were used for this study. Two different dental implant macrodesign were used: cylindric-conical with 3.5 mm of diameter and 9 in length (implant A) and conical with 2.9 mm of diameter and 9 mm in length (implant B). Two surfaces were used: sandblasting and acid etching (surface 1) and sandblasting and acid etching, then maintained in an isotonic solution of 0.9% sodium chloride (surface 2). Four groups were performed (n = 20 implants): Group A1 (implant A with the surface 1), Group A2 (implant A with surface 2), Group B1 (implant B with surface 1), and Group B2 (implant B with surface 2). The mandibular premolars and molars (P1, P2, P3, M1) were removed and, after 2 months of healing, implants were inserted at the crestal and 2 mm subcrestal position related to the buccal bone level. Analysis was performed at 4 and 8 weeks. Histomorphometry with longitudinal measurements and bone implant contact, bone remodeling and implant stability quotient analysis were realized. RESULTS: The surface 2 showed to get more close contact between implant and new bone formed after implant placement and more stability surrounding platform both at 4 and 8 weeks. Surface 2 groups and subrestally placed showed to have better results in terms of linear measurements, with less bone loss and soft tissue distance to the IS. The data showed significant differences among the groups (P < 0.001). CONCLUSIONS: Surface modification (surface 2) has shown to be an effective alternative to conventional surface with better results in situations placed subcrestally and combined with implant design.