Clinical evaluation of the treatment of Class II furcation involvements with bioabsorbable barriers alone or associated with demineralized freeze-dried bone allografts

Background: Class II furcation lesions are a challenging scenario for perio dontal therapy and a serious threat for tooth prognosis. Guided tissue rege neration represents a viable treatment option, but some aspects remain to b e clarified as to the efficacy of bone substitutes used in GTR procedures. The clinical efficacy of demineralized freeze-dried bone allografts (DFDBA) for regenerative procedures is presently under scrutiny. Methods: This study evaluated the adjunctive clinical effects of DFDBA asso ciated with a bioabsorbable (polylactic acid) barrier membrane in the regen erative treatment of human Class II furcation lesions as compared to the sa me type of barrier alone. Twelve patients with bilateral Class II furcation defects on lower first molars participated in the study, In each patient, one tooth was randomly assigned to treatment consisting of open surgical de bridement followed by the placement of DFDBA (GTR+DFDBA, or test group) and a bioabsorbable barrier, while the contralateral side received the same fl ap surgery followed by use of the bioabsorbable membrane alone (GTR, or con trol group). The clinical efficacy of the 2 treatment modalities was evalua ted at 6 and 12 months postoperatively. Measurements included vertical prob ing depth (VPD), horizontal probing depth (HPD), clinical attachment level (CAL), amount of gingival recession (GR), and change in class of clinically detectable furcation involvement (FC). Results: Both treatments yielded significant improvements for all clinical parameters between baseline and 6 and 12 months (P<0.05). The comparison be tween test and control groups revealed significantly greater reduction in H PD (P=0.01) and higher values of GR (P=0.008) for the test group. The mean gain in HPD for test sites was 2.3 mm, while it amounted to 1.7 mm for cont rols. A significantly greater proportion of test sites could be classified postoperatively as Class I defects compared to controls (91% versus 50%, re spectively). Conclusions: The results of this study indicate that significant improvemen ts from baseline occurred in VPD, HPD, CAL, and clinically detectable furca tion involvement after the treatment of Class II furcation lesions with a b ioabsorbable membrane with or without the adjunctive use of DFDBA. In addit ion, the placement of DFDBA in the furcation defect under the bioabsorbable membrane resulted in a greater mean reduction of horizontal probing depth when compared to the regenerative therapy alone.