In vitro evaluation of the type of implant bed preparation with osteotomes in bone type IV and its influence on the stability of two implant systems.

OBJECTIVES 1) To evaluate and compare the stability of two types of implants in an animal model after preparing the implant bed with various sequences of osteotomes in bone type IV. 2) To evaluate the hypothesis of whether or not the sequence of using osteotomes influences the primary implant stability. MATERIAL AND METHOD We selected bone from cow ribs, which in its cross section (the most medullar area of the bone) would be equivalent to a type IV human bone. We used fifteen ribs, in which six implant beds were prepared in each rib block using different preparation protocols for seating three conical Swiss Plus SPB implants of 3.7 x 10 mm versus three MK III parallel wall implants of 4 x 10 mm.Three preparations, each with a diameter, were made for the implants, using osteotomes that progressively increased the diameter of the implant bed. In the first preparation, the complete sequence of osteotomes was used; in the second preparation, the last osteotome was left out; and in the third preparation, the implant was placed after only passing through the first osteotome. Once the implants were seated, we proceeded to evaluate the stability (Osstell ISQ-value). The locations were randomly chosen (by a coin toss). RESULTS AND STATISTICAL ANALYSIS: We performed a statistical analysis of the ISQ values that were obtained during the different preparations carried out for the Mk III and Swiss Plus implants. The average range and standard deviation were calculated. The hypothesis was compared by a two-way variance analysis (type of implant/ different sequences of preparing the implant bed). It was considered significant for a p <0.05. The statistical results obtained for the values of the Mk III implant were significant (p = 0.042). CONCLUSIONS The results of this in vitro study conclude that the tapered shape provides more primary stability to the implant and suggest that a short sequence of osteotomes in bone type IV provide more primary stability than the complete sequence.