An in vivo comparison of wound healing characteristics of two commercial acellular dermal matrices.

OBJECTIVES: Many acellular dermal matrices (ADMs) are available for use in periodontal surgical procedures. However, few studies exist evaluating their in vivo healing properties. The objectives of this study were to compare the wound healing and remodeling of two ADMs used for gingival augmentation procedures in the rat model. MATERIALS AND METHODS: This was a nonrandomized controlled split-mouth study. Envelope flaps were surgically created in the maxillary quadrants of 24 Sprague Dawley rats. Each received either (a) AlloDerm Regenerative Tissue Matrix, or (b) OrACELL. Gingival tissue from one mandibular quadrant served as the untreated control. Six male and six female rats were treated for 7 or 21 days. Biopsies were processed for histologic analysis (H&E, Picro-sirius red, Verhoeff's solution) or RNA analysis (RT-PCR) to analyze the expression of type I collagen (Col1a1), fibronectin (Fn-1) and VEGF-A (Vegf-A). RESULTS: There was a greater density of fibroblasts in OrACELL compared to AlloDerm at both timepoints. There was a greater density of elastin present in AlloDerm compared to OrACELL at 7 days but no differences at 21 days. There were no differences between test groups in the percentage of birefringent collagen or in the expression of Vegf-A or Fn-1. At 7 days, there were significantly more fibroblasts for males in the OrACELL group compared to females. At 21 days, there was a significantly greater expression of Col1a1 for males in the OrACELL group compared to females. CONCLUSIONS: Early wound healing and remodeling of OrACELL appeared to occur more rapidly than AlloDerm and was accelerated in male rats. Whether these results have clinical implications for soft tissue grafting procedures in humans remains to be determined.

Laser identification of residual microislands of calculus and their removal with chelation.

BACKGROUND: During videoscope-assisted minimally invasive surgery which uses a high magnification videoscope to treat periodontal defects, small areas resembling calculus are detected remaining on root surfaces following scaling. These are clinically termed microislands of calculus, which are removed by the use of a chelating agent. This material has not been verified as calculus and the ability of a chelating agent to remove calculus has not been proven. The purpose of this ex vivo study is to verify if the material is calculus and to determine if calculus is removed with a chelating agent. METHODS: Extracted teeth (n = 22) with heavy calculus on root surfaces were selected. A 5-mm2 area containing calculus was scribed on each root. Digital videoscope images were made of the marked areas using only white light and also with only a 655-nm diode laser that causes calculus to fluoresce. The marked areas were root planed until no calculus was visible with 3.5× surgical loupes. Digital images were again made. The test area was then burnished with a chelating agent (EDTA) for 30 seconds and images again made. Using the images, the percentage of the marked root surface containing calculus was calculated. RESULTS: Calculus remained on the roots surfaces after they were judged to be clean using 3.5× loupe magnification. Remaining calculus was reduced after burnishing for 30 seconds with EDTA. CONCLUSIONS: Calculus remains on root surfaces judged to be calculus free using surgical loupes for visualization. Small areas of calculus are reduced or eliminated with a chelating agent.