The effects of laser microgrooves on hard and soft tissue attachment to implant collar surfaces: a literature review and interpretation.

Peri-implant gingiva such as that of teeth should provide a protective barrier against microbial plaque. Recent work has indicated a need for keratinized gingiva of adequate width and thickness to reduce peri-implant soft tissue recession and bone loss.1–3 Gingival tissues surrounding the necks of teeth and implants have similarities, with both consisting of a stratified squamous keratinized epithelium secured by hemi-desmosomes overlying a dense, collagenous lamina propria.4–6 These soft tissue components must be of minimum thickness or “biologic width” to avoid an accommodating degree of crestal bone loss.7–9 The difference around implants compared with teeth is that with the latter, collagen fibers insert directly into cementum as Sharpey fibers, more or less perpendicular to root surfaces.10 In contrast, collagen fibers of peri-implant lamina propria present as a fibrous capsule with fibers oriented parallel and circumferential to the implant surface.11 Collar segments (eg, the portion of the implant root immediately apical to the microgap of two-piece implants) traditionally 1 Dean and Professor and Chairman, Department of Periodontology, Faculty of Dentistry, Islamic Azad University (Khorasgan Branch), Arghavanieh, Isfahan, Iran.