This issue, edited by Dr. Frank Scannapieco, is devoted to "Unanswered Questions in Periodontology." Review articles will help answer clinical questions such as: Can lost bone in furcations be regenerated?; What biomarkers exist to detect active periodontal disease?; Which mouthrinse products are beneficial for plaque control and gingival health?; Do mobility and occlusal trauma impact periodontal longevity?; Can peri-implantitis be treated?; Is there a genetic basis for periodontitis?; What is the minimal sample size for studies of periodontal treatment?; Does treatment of periodontal disease influence systemic disease?; Does periodontal disease cause cancer?; Is the use of photodynamic therapy beneficial to conventional mechanical therapy in the treatment of periodontitis and peri-implantitis?;� Are radiographs the best modality to diagnose and monitor periodontitis?; Does gingival recession require surgical treatment?; and Should antibiotics be prescribed to treat chronic periodontitis?

This issue, edited by Dr. Frank Scannapieco, is devoted to "Unanswered Questions in Periodontology." Review articles will help answer clinical questions such as: Can lost bone in furcations be regenerated?; What biomarkers exist to detect active periodontal disease?; Which mouthrinse products are beneficial for plaque control and gingival health?; Do mobility and occlusal trauma impact periodontal longevity?; Can peri-implantitis be treated?; Is there a genetic basis for periodontitis?; What is the minimal sample size for studies of periodontal treatment?; Does treatment of periodontal disease influence systemic disease?; Does periodontal disease cause cancer?; Is the use of photodynamic therapy beneficial to conventional mechanical therapy in the treatment of periodontitis and peri-implantitis?;� Are radiographs the best modality to diagnose and monitor periodontitis?; Does gingival recession require surgical treatment?; and Should antibiotics be prescribed to treat chronic periodontitis?