forms a zone around the IAJ. Although not yet fully understood, the current theory of the benefit of platform switching is related to the physical repositioning of the IAJ away from the outer edge of the implant and the surrounding bone, thereby containing the inflammatory infiltrate within the width of the platform switch. In line with the supposed mechanism of action, it is not merely the introduction of a platform switch, but the magnitude of the implant-abutment diameter mismatch, that makes a difference. Difference in bone levels became statistically significant when the implant-abutment diameter mismatch was greater than 0.8 mm, providing a 0.4 mm circumferential width of platform switch when the center of the abutment is aligned with and fixed to the center of the implant. Proposed benefits Biologic width Very much like teeth, implants exposed to the oral cavity exhibit what is known as a minimum biologic width. Biologic width is the minimum thickness of soft tissue that envelops the alveolar bone that surrounds teeth and into which endosseous dental implants are placed, and has classically been described as having a mean of 2.04 mm: 0.97 mm of epithelium and 1.07 mm of underlying soft connective tissue. Around implants, biologic width formation has classically led to about 1.5 - 2 mm of bone loss in the vertical dimension at the coronal aspect of the implants because the abutment that attaches to the implant was often removed many times to allow for impression taking, abutment changing and other related clinical functions. As such, the epithelial and connective tissue protection for the bone was unable to reliably form on the continuously disrupted abutment attachment surface and in reaction to this, bone loss occurred on the implant in order to provide the dimension necessary for the epithelium and soft connective tissue attachment to the implant fixture itself—this defined early implant placement and was often colloquially referred to as "bone loss to the first thread." This vertical loss of bone (X in the diagram at right) diminishes the bone-to-implant contact, contributing to a potential decrease in long-term biomechanical stability and has been well researched. Horizontal component of biologic width Recently, the lateral extent of this vertical bone loss around implants has been investigated—in other words, the thickness of bone loss that exists as a halo around the implant at its most coronal aspect—and has been termed the horizontal component of the biologic width