Treatment of multiple adjacent Miller class I and II gingival recessions with a Modified Coronally Advanced Tunnel (MCAT) technique and a collagen matrix or palatal connective tissue graft: a randomized, controlled clinical trial

Background A newly developed collagen matrix (CM) of porcine origin has been shown to represent a potential alternative to palatal connective tissue grafts (CTG) for the treatment of single Miller Class I and II gingival recessions when used in conjunction with a coronally advanced flap (CAF). However, at present it remains unknown to what extent CM may represent a valuable alternative to CTG in the treatment of Miller Class I and II multiple adjacent gingival recessions (MAGR). The aim of this study was to compare the clinical outcomes following treatment of Miller Class I and II MAGR using the modified coronally advanced tunnel technique (MCAT) in conjunction with either CM or CTG. Methods Twenty-two patients with a total of 156 Miller Class I and II gingival recessions were included in this study. Recessions were randomly treated according to a split-mouth design by means of MCAT+CM (test) or MCAT+CTG (control). The following measurements were recorded at baseline (i.e. prior to surgery) and at 12months: Gingival Recession Depth (GRD), Probing Pocket Depth (PD), Clinical Attachment Level (CAL), Keratinized Tissue Width (KTW), Gingival Recession Width (GRW) and Gingival Thickness (GT). GT was measured 3-mm apical to the gingival margin. Patient acceptance was recorded using a Visual Analogue Scale (VAS). The primary outcome variable was Complete Root Coverage (CRC), secondary outcomes were Mean Root Coverage (MRC), change in KTW, GT, patient acceptance and duration of surgery. Results Healing was uneventful in both groups. No adverse reactions at any of the sites were observed. At 12months, both treatments resulted in statistically significant improvements of CRC, MRC, KTW and GT compared with baseline (p<0.05). CRC was found at 42% of test sites and at 85% of control sites respectively (p<0.05). MRC measured 71 +/- 21%mm at test sites versus 90 +/- 18% mm at control sites (p<0.05). Mean KTW measured 2.4 +/- 0.7mm at test sites versus 2.7 +/- 0.8mm at control sites (p>0.05). At test sites, GT values changed from 0.8 +/- 0.2 to 1.0 +/- 0.3mm, and at control sites from 0.8 +/- 0.3 to 1.3 +/- 0.4mm (p<0.05). Duration of surgery and patient morbidity was statistically significantly lower in the test compared with the control group respectively (p<0.05). Conclusions The present findings indicate that the use of CM may represent an alternative to CTG by reducing surgical time and patient morbidity, but yielded lower CRC than CTG in the treatment of Miller Class I and II MAGR when used in conjunction with MCAT.