Porphyromonas gingivalis is one of the major bacteria involved in the formation and progression of chronic periodontitis. Pathogens invading the gingiva face the host's innate immune system at first and later on the acquired immune system which includes secreted antibodies and specialized cells. Although both the arms of the immune system are coordinated to overcome the infection, there are several known mechanisms which help pathogens as Porphyromonas gingivalis evade immunity. As a result, inflammatory mediators secreted by immune cells cause tissue damage and lead the inflammation process towards chronicity instead of clearing the pathogen. Up till recently most of the studies focused on the role of macrophages, dendritic cells and lymphocytes at the response to periodontal pathogenic bacteria while the role of fibroblasts (the most abundant cell in the connective tissue) was less examined. Fibroblasts are spindle shaped cells which have the ability to produce extra cellular matrix and respond to growth factors and cytokines. They are able to affect cells in the infected tissue and contribute to immune response efficiency. As known in the case of lymphocytes, fibroblasts also vary in subtypes, each differs in phenotype, immune interactions, extra cellular matrix production and destruction, migration abilities and so on. Two main fibroblasts subtypes in the oral cavity originate in the gingival tissue and the periodontal ligament anchoring teeth to the surrounding alveolar bone. Amongst the differences between the two are collagen production ability and receptors profile over the cell surface. Considering all that, the investigators aim to obtain and use periodontal ligament and gingival tissues removed anyways during common dental procedures in order to extract the different fibroblasts subtypes residing there and compare their response to Porphyromonas gingivalis.

Inclusion Criteria:

• Healthy men and women over 18 years of age, eligible for signing
• Patient in need for a tooth extraction regardless of the study
• Patient understanding and in consent to the character and the purpose of the study
• Patient with healthy gingival and connective tissue surrounding the tooth to be extracted

Exclusion Criteria:

• Pregnant or nursing women. children or non judgemental patients
• Patient undergoing tooth extraction due to periodontitis or any reason related to a problem in the tooth connective tissue
• patient with a Rontgenic bone loss around the tooth to be extracted.
• Patient with any oral disease other than gingivitis.
• Patients with need of pre-medication prior to invasive procedures.
• Patients with background disease or regular use of medications
• Patients treated with antibiotics in the 2 months preceding the tooth extraction.
• Smoking patients.
• Patients with alcohol abuse.

Healty over 18 years of age eligible for signing patients that go through tooth extraction for reasons not related to the study.