Dr. Peter O. Cabrera

“Gingival recession is one of the most prevalent periodontal pathologies. In this article we examine the different contributing factors to be considered for an accurate diagnosis."
	-

	Recession is commonly defined as the apical migration of the periodontal attachment. From a practical clinical perspective, most clinicians apply a visual standard in diagnosing this type of pathology. From a more detailed analysis, however, what is commonly called gingival recession is really a combination of pathologies that result in bone loss, root damage, decay and significant patient discomfort in the form of root sensitivity.

	Given this variety of presentations, root exposure is a more comprehensive and descriptive term than gingival recession. I propose the term “gingival recession” be eliminated and substituted with a more comprehensive definition, which is “root exposure.” The word recession is generally misunderstood and frequently misdiagnosed, which is why clinicians need to refine and rethink how they look at it.

	There are many factors that can lead to root exposure (see “What causes root exposure"), from thin bone to trauma. Clinicians need to be able to spot it and diagnose it. Diagnosing root exposure should be part of a comprehensive periodontal exam and can be organized in three categories:

 This includes probing depth, notation of bleeding on probing, the distance of the marginal tissue from the cementoenamel junction (CEJ), and root lesions whether they’re the result of trauma, abfraction or abrasive.

There are many structural characteristics that can predispose patients to root exposure.

 is one of the least used diagnostic criteria in periodontal evaluation, and also is one of the most useful. Periodontal biotypes are generally defined as the thick, flat periodontium and the thin, scalloped periodontium. It is in the thin biotype where the patient presents with thin bone and tissue where we are likely to see root exposure. Although root exposure also can occur in the thick biotype, depending on the clinical circumstances, it is more common in the thin biotype.

 in the alveolar process also can be seen in structural evaluation. The more facially or lingually positioned a tooth is in the alveolar process, the thinner the bone becomes and the more likely you are to see root exposure. This can occur with normal wear and tear. Extreme labial or lingual position of the roots can place the tooth outside of the alveolar process.

3. Functional (parafunction, abrasion and restorative trauma).

, especially in the presence of occlusal interferences, can lead to abfractive cervical lesions.

, whether it is the result of aggressive brushing or it’s chemical, can lead to migration of the apical attachment as well as enamel erosion and dentin exposure.

 is violation of the periodontal attachment, either in subgingival preparation or insertion of margins, and has deleterious consequences-typically in the periodontium. The result is inflammation and increased probing depths. In the thin periodontium, we tend to see apical migration of the attachment and thus root exposure.

	In these five cases, you can see different examples of root exposure as well as cases that could be mistaken for root exposure.

	Passive eruption, the migration of the attachment to the CEJ after the tooth has reached its occlusal position, occurs in all individuals. In this 9-year-old patient, there is a discrepancy between the tissues on the lateral incisors versus the central incisors (

). This is a result of passive eruption and not true root exposure as the tissue is located at the CEJ.

	A 29-year-old patient presented with a chief concern of gingival recession in the mandibular anterior segment. She was interested in implant placement in the area of No. 18. The clinical exam shows a thin periodontium with minimal zones of attached tissue. From a skeletal perspective, the CT scan reveals she has very thin bone, and the teeth have been orthodontically tipped facially, which places them outside of the alveolar housing (

	The patient presented with thin periodontium and teeth placed outside of the alveolar housing (

). Tooth No. 29 shows root abrasion as well as significant decay. With the soft tissue reflected for gingival reconstruction, it becomes apparent that the amount of loss of attachment (bone loss) is much greater than what we can see visually. Periodontists often call this “hidden recession,” as this attachment loss is not clearly visible.

	Violation of the attachment during a restorative procedure resulted in apical migration of the attachment and root exposure in a thin biotype (

	What appears to be extensive recession is principally a result of abfraction or abrasion. Soft-tissue reconstruction in this case would be indicated in localized areas only. There is generally adequate attached tissue, and when compared with the teeth that have no root exposure, this patient’s needs are much more occlusal and restorative than they are periodontal (

	Root exposure is about bone loss and root damage, and is a more appropriate term than simple gingival recession. The analysis and diagnosis of root exposure needs to be part of a comprehensive periodontal exam. The importance of early diagnosis and recognition of predisposing factors cannot be overemphasized.

Dr. Peter Cabrera received his Bachelor of Arts degree from Northwestern University and his DDS from the University of Illinois and completed his periodontal residency at Northwestern University Dental School. He lectures nationally and internationally, has a private practice in Chicago and is an affiliate attending at The Children’s Memorial Hospital. To learn more about his practice, visit 

		Click here for a slideshow of products related to this article.

Articles

 THE SET-UP  “Gingival recession is one of the most prevalent periodontal pathologies. In this article we examine the different contributing factors to be considered for an accurate diagnosis." -Dr. Peter O. Cabrera, team lead

Rethinking recession

	Dental implants have been part of mainstream dentistry for several years. One of the keys to their long-term success is preventive maintenance. It is in this regard that the dental hygienist plays a central role in the long-term health and survival of dental implants.

	In addition to the maintenance aspect of dental implants, the hygienist is typically the key figure in patient hygiene instruction. To properly understand his/her role in this field, the hygienist needs to have a detailed knowledge of the structure of the implant/restorative interface, as well as the local anatomy. In this article, I will review the five key factors hygienist need to understand. Although the examples used are basically for single-tooth restorations, the principles are applicable to all types of implant-supported restorations.

	Having a clear understanding of the anatomy of the bone and tissue is central to peri-implant maintenance. Consideration of anatomy typically involves the periodontal biotype, which is an indication of the character and width of the bone and soft tissue.

	The second consideration in anatomy is the position of the implant in three dimensions. Human teeth are typically positioned buccally in the alveolar process. This means the thinnest part of bone is on the buccal. Upon extraction, a portion of the alveolar process on the facial is lost. Although this can be controlled with ridge preservation and bone augmentation procedures, most implants have a lingual or palatal position. This means the restoration’s buccal profile is wider buccal-lingually than the most buccal position of the implant.

	The third consideration in anatomy is the position of the implant with respect to the adjacent teeth.

2. How the crown is attached to the implant

	There are typically two ways in which the restoration is attached to the implant. The most commonly used is the cemented restoration. The abutment is attached to the implant and in turn, the restoration is cemented to the abutment. It is important to debride the abutment crown interface without impinging on the possible biologic attachment to the abutment. Depending on the thickness of the periodontium, there may be an extended sulcus that requires regular maintenance. This is particularly evident in the thick periodontium. It is in this biotype that we are likely to see retained cement as a source of infection. In these cases the hygienist often recognizes the problem, which typically presents as acute inflammation and a purulent exudate.

	The second approach of implant restoration attachment is with the screw-retained restoration. Although there is no cement involved, it is important to understand the exact position of the restorative implant junction as this is where most bacteria are likely to accumulate. 

	In anterior teeth as well as bicuspids, the diameter of the implant typically approximates the diameter of the restoration. Depending on the construction of the crown and the width of the available bone (ie. diameter of the implant), there can be a significant discrepancy between the shape of the crown and the shape of the implant. Rather than having a smooth transition in the contour of the restoration as it emerges from the tissue, we sometimes have a sharp widening of the emergence profile as we go from a circumferential implant platform to the natural shape of the teeth. In these cases, there can be an undercut at the level of the tissue where bacteria and debris can accumulate.

	The emergence profile, in particular the emergence angle that the abutment or restoration will take throughout the tissue, will dictate the difficulty of maintenance. This is particularly important as platform switching for bone preservation has become a popular practice. The hygienist needs to understand the changes in diameter from the implant restorative platform to the free gingival margin to properly instrument and instruct.

4. Position of the margins with respect to the tissue

	This also can be an indication of the probing depth and it varies throughout the circumference of the restoration. Ideally, the margins follow the same profile as the natural tooth with the facial and lingual margins more apically positioned than the interproximal margin. However, many restorations have the same occluso-apical position throughout the circumference. To know how far to instrument, the hygienist needs to be aware of the position of the margins. This also has implications when the implant is adjacent to natural teeth as the position of the margin can affect the health of the natural tooth attachment.

	There are two areas of likely bacterial accumulation that need to be instrumented. These are the interface between the restoration and the abutment as well as the interface between the abutment and the implant. In the cemented crown, there are two possible openings. In the screwed in restoration, there is only one.

	Understanding peri-implant anatomy is a pre-requisite for proper maintenance around implants. Before undertaking the responsibility for implant maintenance, the hygienist should review the pertinent details of the implant restorative interface with the doctor. It is only with this understanding that the hygienist can properly serve his/her role in maintenance as well as instruction. Differences of opinion exist as to how much instrumentation should be done around implants. Armed with the information presented the hygienist can make an intelligent decision on the appropriate instrumentation.

 Dental implants have been part of mainstream dentistry for several years. One of the keys to their long-term success is preventive maintenance. It is in this regard that the dental hygienist plays a central role in the long-term health and survival of dental implants.