6-YEAR CLINICAL-EVALUATION OF HTR SYNTHETIC BONE-GRAFTS IN HUMAN GRADE-II MOLAR FURCATIONS

A biocompatible microporous composite of PMMA (poly-methyl-methacrylat e), PHEMA (poly-hydroxy-ethyl-methacrylate) and calcium hydroxide bone replacement graft material (Bioplant HTR(TM) Synthetic Bone) was eval uated in 16 maxillary molar and 10 mandibular molar Grade II furcation s in 13 patients. Following initial preparation, full thickness flaps were raised to gain access to the furcations; mechanical hand and ultr asonic root and defect debridement and chemical tetracycline root prep aration were performed; furcation and adjacent osseous defects in each patient were grafted with HTR Synthetic Bone; and the host flaps repl aced or slightly coronally positioned. Weekly, then monthly deplaquing was performed until surgical re-entry at 6-12 months. Patients were t hen followed on approximate 3-month recalls for greater than or equal to 6 yr. Evaluation of the primary clinical outcome of furcation grade change showed that in the maxilla 5/16 furcations were clinically clo sed, 9/16 were Grade I, and 2/16 remained Grade II; while in the mandi ble 3/10 were clinically closed, 5/10 were Grade I, and 2/10 remained Grade II. Other significant clinical changes included decrease in mean horizontal furcation probing attachment level from 4.4 mm at surgery to 2.2 mm at re-entry to 2.0 mm at 6 yr, decrease in probing pocket de pth from 5.4 mm at surgery to 3.0 mm at re-entry to 3.2 mm at 6 yr, an d improvement in vertical clinical probing attachment level from 5.4 m m at surgery to 4.2 mm at re-entry to 4.1 mm at 6 yr (all p<0.05 from surgery to re-entry and surgery to 6 yr, n.s. from re-entry to 6 yr vi a ANOVA). These favorable results with HTR polymer are similar to seve ral reports with other graft materials and with GTR barriers, and sugg est that HTR polymer may have a beneficial effect in the clinical mana gement of Grade II molar furcations.