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Objective: To compare the implant–abutment connection microgap between computer‐aided design and computer‐aided manufacturing (CAD/CAM) milled or laser‐sintered cobalt–chrome custom abutments with or without ceramic veneering and titanium stock abutments with or without crown cementation. Material and Methods: Six groups of six abutments each were prepared: (1) CAD/CAM cobalt–chrome custom abutments: milled, milled with ceramic veneering, laser‐sintered, and laser‐sintered with ceramic veneering (four groups: MIL, MIL‐C, SIN, and SIN‐C, respectively) and (2) titanium stock abutments with or without zirconia crown cementation (two groups: STK and STK‐Z, respectively). Abutments were screwed to the implants by applying 30 Ncm torque. All 36 samples were sectioned along their long axes. The implant–abutment connection microgap was measured using scanning electron microscopy on the right and left sides of the connection at the upper, middle, and lower levels. Data were analyzed using the Kruskal–Wallis test (p <.05). Results: Mean values (μm) of the microgap were 0.54 ± 0.44 (STK), 0.55 ± 0.48 (STK‐Z), 1.53 ± 1.30 (MIL), 2.30 ± 2.2 (MIL‐C), 1.53 ± 1.37 (SIN), and 1.87 ± 1.8 (SIN‐C). Although significant differences were observed between the STK and STK‐Z groups and the other groups (p <.05), none were observed between the milled and laser‐sintered groups before or after ceramic veneering. The largest microgap was observed at the upper level in all groups. Conclusions: Titanium stock abutments provided a closer fit than cobalt–chrome custom abutments. Neither crown cementation nor ceramic veneering resulted in significant changes in the implant–abutment connection microgap. [ABSTRACT FROM AUTHOR]

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.