|Gingival Grafts and AlloDerm®, a Critique|
|Sunday, 06 March 2011 10:12|
Gingival recession and/or root sensitivity, and aesthetic concerns involving the anterior or bicuspid teeth are conditions that may require soft tissue management via tissue grafting. Numerous studies and empirical clinical evidence suggests that coronal advanced flap procedures may be useful in correcting attached tissue gingival defects and for use for grafting in implant cases. Recently, numerous web site PR pieces have touted the effectiveness of a specific material called AlloDerm™ for use in reconstruction gingival defects.
AlloDerm® was developed in 1994 by LifeCell for use as a graft for patients with burns. This patented tissue matrix has been used for breast reconstruction, abdominal wall reconstruction and is now recommended for use in facial reconstruction and for managing gingival recession. The material is created from donated human cadaver skin. All of the cells are removed in a patented process. This removal is alleged to allow for the retention of important biochemical and structural components of the tissue without presenting the problem of rejection.
In a web article related to AlloDerm® it is reported that “when placed in the human body, AlloDerm® repairs damaged tissue by providing a foundation for new tissue regeneration. Blood will flow into the preserved vascular channels in AlloDerm® allowing it to be incorporated into the body. As cells move into AlloDerm®, the process of regeneration begins……Alloderm® is transformed into living tissue that not only resembles your own but also functions like your own.” http://www.breastreconstruction.org/InTheNews/AlloDerminBreastReconstruction.html
Two recent case reports suggest that a dermal matrix such as Alloderm® may be a good material for managing soft tissue prior to bone grafting and for treating soft tissue recession defects. However, for localized recession type defects it is also suggested that conventional surgical technique for grafting may not be an appropriate approach in working with this graft material.
The first study, authored by V Ruiz-Magaz, et al, from the Universitat Internacional de Catalunya, Spain, is published in Med Oral Patol Oral Cir Bucal, 2010 (2010 Jan 1;15(1):e61-4; Acellular dermal matrix in soft tissue reconstruction prior to bone grafting. A case report). The authors report that the “Acellular Dermal Matrix (ADM) graft has become increasingly popular as a substitute for donor connective tissue, eliminating the disadvantages described for the autogenous donor graft. The amount of tissue harvested is unlimited, so it gives an option for treating patients that have inadequate harvestable tissue or that present a large defect to be treated. The outcome of using ADM as a matrix for soft tissue reconstruction 12 weeks before bone grafting can reduce the risk of exposure and failure of the bone graft.” They further suggest that the use of the ADM is particularly important when a large section of tissue is needed as it eliminates the potential problem with donor site issues such as “necrosis of the palate, fibromucosa and bone exposition (read ‘exposure’), pain and bleeding”.
The second report is authored by JB Taylor, et al, and published in the Int J Periodontics Restorative Dent (2010 Oct; 30(5):513-21). This case study describes a modified surgical technique that they feel is necessary to successfully place acellular dermal matrix gingival grafts. The specific steps are described and a rational for the surgical technique is described. They conclude that the “technique has been predictable clinically, with results comparable to those achieved using autogenous tissue.” However, they also conclude that the “results with respect to the adjunctive use of acellular dermal matrix were controversial.”
A number of anecdotal responses about acellular dermal matrix material (Alloderm®) can be found on the WEB. Robert D on the site: http://www.osseonews.com/alloderm-and-dental-implants/ (April 30th, 2010) says “Yes I have used Alloderm® for years and have had multiple negative and positive experiences. First off I want to say when using Alloderm® in dental you CAN NOT leave it exposed, because it has a necrotic odor and a discoloration effect, this is due to it being ”aseptically treated- not sterilized .If you want to leave soft tissue exposed make sure it’s sterilized tissue or ‘Irradiated ‘, this is the process which the cadaver tissue undergoes at the tissue bank. AC Dermis is great for leaving tissue exposed and it won’t discolor or have a foul odor. It also seems to have a higher tensile strength than most other collagen products. Overall I believe Alloderm® is a good product except when left exposed.” The comment regarding smell is echoed by a number of other responders as well.
Although there are numerous anecdotes and several case studies, in reviewing the published literature related to acellular dermal matrix material it is apparent that there are very few supportive case series and no supporting prospective studies or randomized controlled trials at the present time assessing its efficacy for use as oral grafting material.
The HUB was able to identify one relatively recent published systemic review that assesses the literature with respect to coronally advanced flap procedures.
In this article, Cairo, U. Pagliaro, and M. Nieri report on a review of 25 RCTs evaluating 794 Class 1 and II recession lesions in 520 patients. They suggest that the evidence reveals that coronally advanced flaps are associated with a significant mean recession reduction and complete root coverage (Treatment of gingival recession with coronally advanced flap procedures: a systematic review. J Clin Periodontol. 2008 Sep;35(8 Suppl):136-62). They also note that the addition of a connective tissue graft or an enamel matrix derivative enhanced both the recession reduction and complete root coverage.
A recent web article in Dentistry.co.uk presents a case involving AlloDerm® as an intervention for management of gum recession http://www.dentistry.co.uk/news/3725--Cosmetic-dentistry-Oral-health-Smile-makeovers-Treating-gum-recession-with-Alloderm. In summary, it reports that there are minimal side-effects other than initial swelling and mild bruising and that healing is fast and the gums appear as natural as “your own restored and healthy gum tissue.” It further states that “this…quick fix treatment….lasts a lifetime” and that “Alloderm® allows for the predictable treatment of receding gums and is a major breakthrough at both cosmetic and wider health levels”. Included are before and after pictures showing the gingival recession and the post surgical result.
It should be appreciated, however, that use of this procedure is not without risk. At present there are over ten online sites in the USA recruiting patients that have had a variety of AlloDerm® grafts for the purpose of class action litigation. However, none as yet mention gingival grafting.
Cost may be another issue related to the use of an AlloDerm® graft to repair gingival recession. Jessie Spicer, August 28th, 2008, says regarding cost: “I recently had this procedure completed for one tooth and it cost $1600.00. I wish I had done more research before consenting to this procedure. Rather than letting bone grow back, I was convinced that this was a better support for my implant. I am having problems with the AlloDerm® expanding too much. It has raised the gum line even on the front tooth next to it and has bubbled out a bit above all of my top teeth. It has affected the roof of my mouth and even one nasal passage. I feel a lot of pressure with my implant pushing against the newly formed cells. A constant reminder of wishing I made a wiser decision”. (http://www.osseonews.com/alloderm-and-dental-implants/) This comment may represent a singular problem or a more profound issue with respect to the use of AlloDerm®.
In conclusion, AlloDerm® may have application in the restoration of gingival recession lesions and for the correction of other gingival defects. However, its use at present is not supported by published research other than some limited case studies and anecdotal comments. If this material is to be considered for use in the manner suggested by advocating clinicians the company should initiate and complete prospective controlled or comparative studies to validate its longevity and safety with oral placement.
Submitted by Dr Jeff Burgess, Editor in Chief