Emergence Profile

Emergence profile is defined as the contour of a restoration as it relates to its emergence from the circumscribed soft tissues.^8,9 It specifically represents the restoration region located between the implant platform and the soft tissue cervical margin (Figure 1).^4,7 The emergence profile allows a transition from the narrow diameter cylindrical implant platform to the visibly wider cervical portion of the restoration.¹ Ideally, the transition from the implant platform to the cervical margin of the restoration should be smooth and gradual. However, correct three-dimensional surgical implant positioning and sufficient tissue volume are required to achieve optimal emergence profile.^4,6,7 The emergence profile has implications in esthetics as well as in maintaining the peri-implant soft tissue health.^7,10 A restoration with an optimal, biologically contoured emergence profile provides support to the perimucosal tissues around the implant restoration, hence, it is rarely associated with the formation of proximal and/or buccal/lingual food traps.¹¹ Developing a restorative contour of optimal emergence profile, is one of the most significant challenges in implant therapy.¹²

Figure 1. Emergence Profile

Based on the response of the peri-implant mucosal tissues to abutment/crown contour modifications the emergence profile is further divided into two regions: the superficial/critical contour and the deep/subcritical contour (Figure 2).⁷ The critical contour is associated with the cervical margin of the restoration.⁷ It dictates the mucosal margin level, architecture, and shape of the tooth in the cervical region.⁷ The subcritical contour is located immediately coronal to the implant platform and extends coronally to the critical contour.⁷ It helps volumetrically support the drape of the peri-implant mucosa and harbors the supracrestal tissue attachments.⁷ The deep/subcritical contour should help facilitate a gradual and harmonious transition from the implant platform to the critical contour.⁷ However, this can only be appropriately facilitated when the implant is positioned at an optimal apical-coronal depth at the time of surgical placement.⁷

Figure 2. Critical and Subcritical Contours of a Restoration

The critical and subcritical contours can help alter the soft tissue architecture.^1,7 These contours can be customized and thoughtfully modified as needed during the healing/transitional phase to maintain/recreate the soft tissue form.^1,3,7 The critical and subcritical contours may be concave, flat, or convex.⁴ The facial critical contour affects the zenith, the position of the labial mucosal margin, and the apparent length of the clinical crown whereas the interproximal critical contour affects the apparent shape of the clinical crown (triangular or square).⁷ A convex facial critical contour is planned (to support the marginal tissues) when the implant is positioned lingually or when there is a need to transpose the peri-implant mucosal margin apically.⁴ Conversely, a flat or concave facial critical contour is designed for implants that are positioned labially or when there is a need to transpose the peri-implant mucosal margin coronally.⁴

The subcritical facial contour is usually concave or flat in shape and helps support the tissues in their existing position.^4,6 However, a convex subcritical contour may be designed on the facial aspect, when the soft tissue form appears deficient facially.^4,6 Subcritical contour in the interproximal region is usually concave or straight in esthetic areas and straight in posterior sites; it is planned to be convex only when tissue support is necessary or when there is a slight deficiency.^4,6 A concave subcritical contour in the midfacial and interproximal areas helps facilitate soft-tissue ingrowth.⁶

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