Articles series, part 2: Tolerances in implant dentistry. Effects of tolerances on the implant performance: an urgent warring about multiple non-continuous implant abutment connections` contacts.

Tolerances are present as an integral part of the modern manufacturing. We should deal with as an unavoidable phenomenon that could ruin the treatment if we choose the poor designs criteria. Multiple implant abutment connections are strongly prohibited due to the damaging interferences that produced by the misfitting of the abutment inside of the implant. We want to demonstrate the mechanical effect of negligence of tolerances on the performance of the implant abutment connections. Mismatch when occur could leave a gap at the upper connection or at the lower connection. Engineering descriptions are highly desirable in these conditions.