Running room

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A This radiograph demonstrates an emergence profile that ignores the gingival tissue, generally presenting clinically with black triangles and food traps on either side of the implant. The crown (white) emerges supragingivally and does not take advantage of the available running room of 3mm. Instead, a 3mm ti-base was used.
B This emergence profile respects the gingival architecture and emerges fully subgingivally. Emergence profile.jpg
A This radiograph demonstrates an emergence profile that ignores the gingival tissue, generally presenting clinically with black triangles and food traps on either side of the implant. The crown (white) emerges supragingivally and does not take advantage of the available running room of 3mm. Instead, a 3mm ti-base was used.
B This emergence profile respects the gingival architecture and emerges fully subgingivally.
Implant platforms are circular in nature and generally exhibit a smaller diameter than the eventual crowns to be placed. Because crowns are wider, the contour of the crown is said to emerge (get wider as it ascends). In this facial view, it is desirable that the full emergence occur under the gum line (subgingivally) rather than above the gum line (supragingivally). The vertical dimension between the implant platform and the gingival margin is termed running room. Runningroom.png
Implant platforms are circular in nature and generally exhibit a smaller diameter than the eventual crowns to be placed. Because crowns are wider, the contour of the crown is said to emerge (get wider as it ascends). In this facial view, it is desirable that the full emergence occur under the gum line (subgingivally) rather than above the gum line (supragingivally). The vertical dimension between the implant platform and the gingival margin is termed running room.

In implant dentistry, running room refers to the apico-coronal distance between the platform of a dental implant and the gingival margin. It is a critical factor in restorative implant dentistry because it is effectively the "vertical distance [available subgingivaly] to make a transition from the smaller diameter prosthetic platform of an implant to the larger cross-sectional cervical shape of the tooth being restored." [1] The term was coined by Jonathan Zamzok, a Manhattan prosthodontist, in the late 1990s. [2]

Rationale

Adequate running room is necessary to allow the implant-supported crown to exhibit a tooth-shaped contour despite the smaller diameter and circular nature of implant platforms. [3] For example, the mean mesial-distal dimension of a maxillary central incisor at the points at which it contacts the adjacent teeth is 8.6 mm, and the mean mesial-distal dimension of the same tooth at the cementoenamel junction (CEJ) is 6.4 mm. [4] Even though the implant diameter chosen for the maxillary central incisor is usually around 4–5 mm, the supragingival tooth contours need to mimic those of the natural tooth if esthetic success is intended.

As the anatomical crown and root tapers towards the apex, the mesial-distal dimension decreases, and so the mean mesial-distal dimension at the marginal crest of bone, which lies approximately 2 mm apical to the CEJ, is smaller. The tooth has the apico-coronal distance from the marginal crest of bone to the contact point in order to increase from the much narrower mesial-distal dimension to the greater mesial-distal dimension, and this distance is subgingival (below the gum line). Running room refers to this subgingival apico-coronal distance.

In general, it is recommended that implants be given approximately 3mm of running room in compliance with the rule of thumb that implants should be placed as deep as necessary and as shallow as possible. [5]

When implants are placed too palatally or lingually due to aberrant anatomical landmarks, bone resorption or surgical error, it is wise to place the implant more apically to increase the available running room in order to allow for a more convex emergence profile and avoid a buccal ridge-lap of the prosthetic crown in fixed partial denture cases. [5] Similarly, when narrower than normal implant connections are used, deeper placement may enhance one's ability to generate an optimal emergence profile.

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Human teeth function to mechanically break down items of food by cutting and crushing them in preparation for swallowing and digesting. As such, they are considered part of the human digestive system. Humans have four types of teeth: incisors, canines, premolars, and molars, which each have a specific function. The incisors cut the food, the canines tear the food and the molars and premolars crush the food. The roots of teeth are embedded in the maxilla or the mandible and are covered by gums. Teeth are made of multiple tissues of varying density and hardness.

<span class="mw-page-title-main">Dental implant</span> Surgical component that interfaces with the bone of the jaw

A dental implant is a prosthesis that interfaces with the bone of the jaw or skull to support a dental prosthesis such as a crown, bridge, denture, or facial prosthesis or to act as an orthodontic anchor. The basis for modern dental implants is a biological process called osseointegration, in which materials such as titanium or zirconia form an intimate bond to the bone. The implant fixture is first placed so that it is likely to osseointegrate, then a dental prosthetic is added. A variable amount of healing time is required for osseointegration before either the dental prosthetic is attached to the implant or an abutment is placed which will hold a dental prosthetic or crown.

<span class="mw-page-title-main">Crown (dental restoration)</span> Dental prosthetic that recreates the visible portion of a tooth

In dentistry, a crown or a dental cap is a type of dental restoration that completely caps or encircles a tooth or dental implant. A crown may be needed when a large dental cavity threatens the health of a tooth. Some dentists will also finish root canal treatment by covering the exposed tooth with a crown. A crown is typically bonded to the tooth by dental cement. They can be made from various materials, which are usually fabricated using indirect methods. Crowns are used to improve the strength or appearance of teeth and to halt deterioration. While beneficial to dental health, the procedure and materials can be costly.

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<span class="mw-page-title-main">Cementoenamel junction</span>

Cementoenamel junction (CEJ) is defined as the area of the union of cementum and enamel at the cervical region of the tooth. It is a slightly visible anatomical border identified on a tooth. It is the location where the enamel, which covers the anatomical crown of a tooth, and the cementum, which covers the anatomical root of a tooth, meet. Informally it is known as the neck of the tooth. The border created by these two dental tissues has much significance as it is usually the location where the gingiva attaches to a healthy tooth by fibers called the gingival fibers.

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<span class="mw-page-title-main">Maxillary central incisor</span> Tooth

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<span class="mw-page-title-main">Crown lengthening</span> Dental procedure

Crown lengthening is a surgical procedure performed by a dentist, or more frequently a periodontist, where more tooth is exposed by removing some of the gingival margin (gum) and supporting bone. Crown lengthening can also be achieved orthodontically by extruding the tooth.

Occlusion, in a dental context, means simply the contact between teeth. More technically, it is the relationship between the maxillary (upper) and mandibular (lower) teeth when they approach each other, as occurs during chewing or at rest.

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<span class="mw-page-title-main">Furcation defect</span>

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<span class="mw-page-title-main">Mandibular incisive canal</span>

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<span class="mw-page-title-main">Platform switching</span>

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<span class="mw-page-title-main">Angularis nigra</span> Small triangle-shaped gap which often occurs between the teeth, near the gums

Angularis nigra, Latin for 'black angle', also known as open gingival embrasures, and colloquially known as "black triangle", is the space or gap seen at the cervical embrasure, below the contact point of some teeth. The interdental papilla does not fully enclose the space, leading to an aperture between adjacent teeth. This gap has many causes including gingival recession, and gingival withdrawal post-orthodontic work. Interdental "black triangles" were rated as the third-most-disliked aesthetic problem below caries and crown margins. Treatment of angularis nigra often requires an interdisciplinary approach, involving periodontal, orthodontic and restorative treatment. Possible treatments to correct angularis nigra include addition of composite resin in the space, veneer placement, or gum graft. Angularis nigra is generally only treated based on the aesthetic preference of the patient.

<span class="mw-page-title-main">Radial plane</span>

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References

  1. Cavallaro Jr. JS, Greenstein G: Prosthodontic complications related to non-optimal dental implant placement. In Froum, editor: Dental Implant Complications: Etiology, Prevention, and Treatment. Oxford: Wiley-Blackwell 2010. page 157
  2. Zamzok J. Nonsurgical soft tissue sculpting. Alpha Omegan 1997;90:65-69
  3. Smith RB, Tarnow DP. Classification of molar extraction sites for immediate dental implant placement: technical note. Int J Oral Maxillofac Impl 2013;28:911-916
  4. Scheid RC, Woelfel JB. Woelfel's Dental Anatomy: its relevance to dentistry, Lippincott Williams & Wilkins, 2007 ISBN   0781768608
  5. 1 2 Greenstein G, Cavallaro J. The relationship between biologic concepts and fabrication of surgical guides for dental implant placement. Compendium 2007;28(4):130-137