Papillae tunneling techniques (PTT) are a new approach toward regeneration of isolated intrabony defects. Compared to regular papillae preservation techniques, PTT rely on complete preservation of involved interdental papillae, providing optimal healing environment for periodontal wound. Surgical access is therefore gained either by vertical incision in vestibulum, or by short releasing incision on adjacent tooth. Interdental tissue is then carefully raised in a full thickness manner by tunneling instruments, root surface thoroughly cleaned by the ultrasound scaler or Gracey curettes and defect filled with the biomaterial of choice.

While the success and aesthetic results of non-incised papillae techniques are well documented, no paper so far compared clinical results of papillae preservation techniques with different biomaterials.

Therefore, the aim of our study is to compare gain of clinical attachment level (defined by sum of pocket probing depth and recession) to regular papillae preservation techniques, and to prove non-inferiority of Gel 40® (collagen matrix, loaded with micronized heterologous bone) to Gen-Os® (granulated cortico-cancellous heterologous bone mix).

Secondary objectives include analysis of aesthetic parameters - differences in recession and tip of the papillae location before and after the treatment.

Inclusion Criteria:

• periodontitis stage III/IV
• at least one periodontal lesion with pocket probing depth > 5 mm, limited by 2 or more bone walls and intrabony component > 3 mm.
• good oral hygiene with plaque index and sulcular bleeding index < 30%.
• systemically healthy
• smokers and non-smokers

Exclusion Criteria:

• systemic diseases that contraindicate the treatment,
• on medications that affects periodontal healing
• pregnant or lactating women
• one wall intrabony defects
• defects that involve buccal and lingual side of the tooth
• tooth with incorrect endodontic treatment or restoration