Root cementum may modulate gene expression during periodontal regeneration: a preliminary study in humans.
BACKGROUND
Previous data demonstrated that root cementum may affect periodontal regeneration. As such, this study aimed to explore further possible mechanisms involved in this process by investigating in humans whether root cementum modulates gene expression in the regenerating tissue formed under membrane-protected intrabony defects.


METHODS
Thirty subjects with deep intrabony defects (> or =5 mm; 2- or 3-wall) were selected and assigned to the control or test group. The control group received scaling and root planing with the removal of granulation tissue and root cementum; the test group underwent removal of granulation tissue and soft microbial deposits by cleaning the root surface with a microbrush and saline solution, aiming at cementum preservation. Guided tissue regeneration (GTR) was applied to both groups. Twenty-one days later, the newly formed tissue under the membrane was assessed for the expression of the following genes: alkaline phosphatase (ALP), osteopontin (OPN), osteocalcin (OCN), platelet-derived growth factor-alpha (PDGFA), bone sialoprotein (BSP), and basic fibroblast growth factor (bFGF).


RESULTS
Data analysis demonstrated that mRNA levels for PDGFA, BSP, and bFGF were higher in the sites where root cementum was kept in place compared to the sites where root cementum was removed completely as part of the periodontal therapy (P <0.05); in contrast, OCN levels were lower (P <0.05). No difference for ALP or OPN was observed between the control and test groups (P >0.05).


CONCLUSIONS
Root cementum may modulate the expression of growth and mineral-associated factors during periodontal regeneration.
Gonçalves
Patricia F
PF
Department of Dentistry, Division of Periodontics, School of Biologic and Health Sciences, Federal University of Vales of Jequitinhonha and Mucuri, Diamantina, MG, Brazil.
Lima
Liana L
LL
Sallum
Enilson A
EA
Casati
Márcio Z
MZ
Nociti
Francisco H
FH
D000328:Adult; D000469:Alkaline Phosphatase / Q000096:biosynthesis; D016301:Alveolar Bone Loss / Q000601:surgery*; D001861:Bone Regeneration / Q000235:genetics*; D003739:Dental Cementum / Q000502:physiology*; D012534:Dental Scaling; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000096:biosynthesis; D005786:Gene Expression Regulation; D016557:Guided Tissue Regeneration, Periodontal; D006801:Humans; D058574:Integrin-Binding Sialoprotein; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000096:biosynthesis; D053495:Osteopontin / Q000096:biosynthesis; D010982:Platelet-Derived Growth Factor / Q000096:biosynthesis; D012795:Sialoglycoproteins / Q000096:biosynthesis
C546871:IBSP protein, human; D058574:Integrin-Binding Sialoprotein; D010982:Platelet-Derived Growth Factor; D012795:Sialoglycoproteins; C075278:platelet-derived growth factor A; D016222:Fibroblast Growth Factor 2; D015675:Osteocalcin; D053495:Osteopontin; D000469:Alkaline Phosphatase