HYDROXYAPATITE CEMENT IMPLANT FOR REGENERATION OF PERIODONTAL OSSEOUSDEFECTS IN HUMANS

A NEWLY DEVELOPED CALCIUM PHOSPHATE cement used to promote bone regene ration in craniofacial defects was examined to determine its potential for treatment of periodontal osseous defects. Sixteen patients with m oderate to severe periodontal disease and 2 bilaterally similar vertic al bony defects received initial therapy including scaling and root pl aning followed by treatment with either calcium phosphate cement, flap curettage (F/C) or debridement plus demineralized freeze-dried bone a llograft (DFDBA). Standardized radiographs were exposed at baseline an d 12 months postsurgery for computer assisted densitometric image anal ysis (CADIA). The extent of the bony defect was determined during init ial and 12 month re-entry surgery. Within 6 months of implant placemen t, 11 of 16 patients treated with calcium phosphate cement exfoliated all or most of the implant through the gingival sulcus. At all 16 test sites, a narrow radiolucent gap formed by 1 month postsurgery at the initially tight visual interface between the radiopaque calcium phosph ate cement and the walls of the bony defect. Mean probing depth reduct ion and clinical attachment gain at sites treated with calcium phospha te cement were 1.6 mm and 1.3 mm, respectively at 1 year. Minimal bony defect fill was accompanied by mean crestal resorption of 1.4 mm. Alv eolar crestal resorption at sites with calcium phosphate cement was st atistically significant (P = 0.001). These findings contrasted with th e more favorable outcomes for controls treated with DFDBA or F/C. DFDB A sites exhibited probing depth reduction of 3.1 mm, clinical attachme nt gain of 2.9 mm, and defect fill of 2.4 mm. Respective clinical chan ges at F/C sites were 2.4 mm, 1.4 mm, and 1.1 mm. CADIA revealed clini cally significant trends between the three treatment modalities at var ious areas-of-interest, Based on the findings of this study, there is no rationale available to support the use of hydroxyapatite cement imp lant in its current formulation for the treatment of vertical intrabon y periodontal defects.