Effect of dental cementum on genes modulate during periodontal regeneration. Study in humans

Author(s)

Liana Linhares Lima

• Document type: Master's Dissertation
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2007-02-14

Examining board members

Francisco Humberto Nociti Junior; Patricia Furtado Gonçalves; Marcio Zaffalon Casati

• Advisor: Francisco Humberto Nociti Junior; Sérgio de Toledo

Abstract

The aim of the present study was to evaluate the influence of the dental cementum on gene expression during periodontal regeneration. Thirty patients were selected presenting chronic periodontal disease and with at least one tooth presenting vertical bone defect without endodontic involvement and referred to extraction. The patients were divided into two groups according to history or not of periodontal therapy: Control: Scaling and root planning was made by means of hand androtators instruments in order to remove soft and hard deposits as well as all root cementum; Test: Removal of only soft microbial deposits and cleaning of the root surface with micro brush was performed with the aim to preserve maximum root cementum. Both groups were treated with guided tissue regeneration (GTR), with non reasonable membranes (Goretex®) covering the buccal and lingual aspects of the defect and the flaps were coronally positioned and sutured. After 21 days, the tissue formed under the membrane was collected and stored for polymerase chain reaction (PCR) analysis; the tooth was extracted and submitted to histological evaluation. Data analysis did not show any statistical difference between the two experimental groups and the following genes expression: alkaline phosphatase, osteopontin (OPN), "receptor activator of NF-kß ligand¿ (RANKL), osteoprotegerin (OPG), interleukin 1 (IL-1ß), interleukin 6 (IL-6) and matrix metalloproteinase 9 (MMP-9). On the other hand, the presence of dental cementum significantly affected the following genes: osteocalcin (OCN) (3.84±1.01 and 1.83±0.57; p=0.001), type I collagen (3.98±1.07 and 2.85±0.99; p=0.024), type III collagen (0.55±0.15 and 0.45±0.13;p=0.008), platelet - derived growth factor (PDGF) (1.78±0.45 and 2.53±0.40;p=0.001), matrix metalloproteinase 2 (MMP-2) (1.72±0.18 e 1.27±0.27; p=0.001) and interleukin 4 (IL-4) (14.89±4.14 e 24.01±7.00; p=0.002). Therefore, within the limits of this study, it can be concluded that dental cementum can modulate periodontal regeneration (AU)