Acellular Dermal Matrices Accelerated Healing In An In Vivo Study

Objectives: The objectives of this study were to compare, in vivo, the wound healing and remodeling of two commercial acellular dermal matrices (ADM) used for gingival augmentation in periodontal surgical procedures.
Methods: This was a non-randomized controlled split-mouth study. Envelope flaps were surgically created in the maxillary quadrants of twenty-four Sprague Dawley rats. Each envelope flap was assigned to receive either (1) AlloDerm^TM RTM or (2) OrACELL^TM. Gingival tissue from one mandibular quadrant served as the untreated control. Six male and six female rats were sacrificed at 7- and 21-days. Biopsies were obtained and processed by H&E, Picro Sirius Red, Verhoeff’s, IHC and RT-PCR for histologic, immunohistologic and molecular analysis. A blinded evaluation of soft tissue thickness, recession and erythema were also performed based on clinical photographs taken at the time of biopsy.
Results: Both ADM groups presented with a significantly greater number of fibroblasts, greater density of collagen and elastin fibers and increased tissue thickness compared to controls. Both ADMs demonstrated similar expression of COL1 that was significantly greater than that of controls. The male samples had a slightly greater density of elastin fibers in the 7-day OrACELL^TM group compared to the 7-day AlloDerm^TM group. Picro Sirius Red staining had a significantly increased density of collagen fibers in OrACELL^TM samples compared to AlloDerm^TM at 7-days. IHC staining for PECAM-1 demonstrated increased angiogenesis at 21-days compared to 7-days. There was increased soft tissue thickness for the 21-day AlloDerm^TM samples compared to the 21-day OrACELL^TM samples. Reduced recession and erythema from 7- to 21-days was observed for both ADM groups.
Conclusions: Early matrix remodeling of AlloDerm^TM occurred faster than OrACELL^TM in Sprague Dawley rats. However, by 3 weeks, similar fibroblast numbers, collagen density and angiogenesis were observed in tissues implanted with each acellular dermal matrix.