Krekeler G, Schilli W, Diemer J
Int J Oral Surg. 1985 Dec;14(6):504-8. doi: 10.1016/s0300-9785(85)80056-9.
The necessity of an area of attached gingiva around penetrating implants was examined in 26 patients. It was demonstrated that plaque corneal in the major factor in avoiding inflammatory reactions.