Summary: Alloplastic bone graft materials are widely been used in combination with barrier membranes to achieve guided tissue regeneration in the treatment of periodontal intrabony defects. This study was designed to evaluate the clinical outcome of a composite material, beta tricalcium phosphate in combination with calcium sulphate in the treatment of periodontal intrabony defects. The combination of these materials is believed to aid in guided tissue regeneration owing to their properties. Thirty nine intrabony defects in 21 patients were treated with Fortoss ® Vital (Biocomposites, Staffordshire, UK). Clinical parameters were evaluated including changes in probing depth, clinical attachment level/loss and gingival recession at baseline and one year postoperatively. The mean differences in measurements between the baseline and one year postoperatively are a reduction of 1.98±1.16 mm (p=0.000) in case of probing depth and a gain of 1.68±1.12 mm (p=0.000) in clinical attachment level and an increase of 0.31±0.67 mm (p=0.009) in gingival recession measurements. The study results show that the treatment with a combination of beta tricalcium phosphate and calcium sulphate led to a significantly favorable clinical improvement in periodontal intrabony defects one year postoperatively.