Biologic Width Demystified

Dental Publication / Article Details

Biologic Width Demystified

Author(s):

Richard Erickson, MS, DDS

Date Added:

1/1/2001

Summary:

Much fuss is justifiably made by many clinician speakers over violating the biologic width in crown margin placement. We've all seen seminar slides of chronically inflamed tissue around a crown in violation of this sacred region. But what exactly is this so-called biologic width? Why when despite your best efforts to esthetically hide a crown margin in the sulcus, it comes peeking back at you at the next prophy visit? John Kois answered these questions recently1 much more clearly than I have ever heard in a presentation and here are the highlights.

Some healthy dimensions of the gingival area are needed in order to compare to what is abnormal. As you can see on the diagram at left, a kind of symmetry exists in normal healthy gingiva: 1mm sulcular depth, 1mm attached epithelium and 1mm connective tissue before the crest of the bone is reached. This is the biologic width. 85% of healthy patients will exhibit this 3mm dimension, while 2% will be less than 3mm and 13% will be greater than 3mm. Also, the distance between the CEJ and the crest of bone is 2mm on average. When this CEJ to crestal bone distance is less than 2mm, the gingiva ride up the clinical crown making the tooth appear submerged and short. If the CEJ to crestal bone distance is greater than 2mm, the CEJ may be exposed and the tooth will appear too long.

To summarize then, the biologic width is equal to 3mm: 1mm sulcular depth, 1mm attachment epithelium and 1mm connective tissue above the crestal bone. This is true on the broad facial surface. In the proximal papillae area, the correct biologic width increases to 4mm. This can be measured on any tooth using the "sounding" technique.

A Biometric Approach To Aesthetic Crown Lengthening: Part 1 - Midfacial Considerations
Although human dental anatomy is taught in university curricula, clinicians often witness restorations that are not proportional to one another. Dental restorations should also be proportional to periodontal supporting tissues as an essential aspect of dental anatomy. Measurements can be performed directly on a patient’s teeth with aesthetic gauges used to confirm the correct position of the supporting osseous topography. This article demonstrates a technique using these gauges to objectively determine the correct position of the underlying hard tissues and render predictable, aesthetic treatment.

Author(s):

Stephen J. Chu, DMD, MSD, CDT; Mark N. Hochman, DDS

View Article>>

Restorative Space Management: Treatment Planning & Clinical Considerations for Insufficient Space
In attempting to provide a restorative solution for cases that have been compromised by spatial considerations, clinicians have traditionally opted for an orthodontic approach that did not provide optimal aesthetics due to changes in tooth morphology, specifically tooth size and shape as a result of dental deterioration. With the advent of contemporary aesthetic materials and preparation techniques, clinicians and technicians are now empowered to deliver a penultimate result with minimal compromise to the surrounding dentition. This article presents the clinical and laboratory considerations that must be addressed when providing a prosthetic restoration for crowded teeth.

Author(s):

Stephen J. Chu, DMD, MSD, CDT; Jason Kim, CDT, MDT, Galip Gurel, DDS, George Cisneros, DMD

View Article>>

CAD/CAM Update - Technologies and Materials and Clinical Perspectives
Because of the growing confusion as to what these technologies are, what they will do, and, more importantly, what the clinical and laboratory guidelines for using these materials and techniques are, this article will address the important points of the CAD/CAM market and technology.

Author(s):

Edward A. McLaren, DDS, MDC; Lu Hyo, MDC

View Article>>