Sub-antimicrobial doses of doxycycline decreased bone loss related to ligature-induced periodontitis in hypertensive rats.

BACKGROUND/OBJECTIVE: The beneficial effects of sub-antimicrobial dose doxycycline (SDD) associated with nonsurgical periodontal therapy are well documented. Recently, the effects of SDD on metalloproteinases have been investigated in the treatment of hypertension. The aim of this study was to evaluate the effects of SDD on ligature-induced periodontitis in spontaneously hypertensive rats (SHR). METHODS: Fifty-four adult male rats were divided into three groups: SHR-C, SHR-L and SHR-L-DOX (C - Control; L - Ligature). In group SHR-L-DOX, animals were treated with daily 5 mg/kg SDD administration. In L groups, a ligature remained around mandibular first molars for the first 10 days. Each group was divided for euthanasia at 10 or 21 days. Microtomographic and histometric analyses were performed. Osteoclastogenesis was evaluated by tartrate-resistant acid phosphatase (TRAP) assay and gene expression of 84 inflammatory mediators by polymerase chain reaction (PCR) array. RESULTS: Group SHR-L-DOX presented reduced systolic blood pressure when compared with group SHR-L at both 10 and 21 days (p < 0.05). Group SHR-L-DOX showed decreased bone and attachment loss in comparison with group SHR-L at both 10 and 21 days (p < 0.05). SDD treatment reduced the amount of TRAP-positive cells at 10 days (p < 0.05). Group SHR-L-DOX showed a downregulated inflammatory genes profile in comparison with SHR-L at 10 and 21 days. CONCLUSION: SDD therapy exerted systemic modulatory effect on inflammation with reduced periodontal tissue destruction in hypertensive rats.

Adjunct effect of the antimicrobial photodynamic therapy to an association of non-surgical and surgical periodontal treatment in modulation of gene expression: a human study.

BACKGROUND: This study has evaluated the effect of antimicrobial photodynamic therapy (aPDT) used in conjunction with non-surgical and surgical periodontal treatment (PT) in modulating gene expression during periodontal wound healing. METHODS: Fifteen patients with chronic periodontitis, presenting bilaterally lower molars with class III furcation lesions and scheduled for extraction, were selected. In initial therapy, scaling and root planing (SRP) was performed in the Control Group (CG), while SRP+aPDT were performed in the Test Group (TG). 45days later, flap surgery plus SRP, and flap surgery plus SRP+aPDT were performed in the CG and TG, respectively. At 21days post-surgery, the newly formed granulation tissue was collected, and Real-time PCR evaluated the expression of the genes: tumor necrosis factor-α, interleukin-1ß, interleukin-4, interleukin-10, matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase-2 (TIMP-2), osteoprotegerin (OPG), receptor activator of nuclear factor-κB ligand (RANKL), type I collagen, alkaline phosphatase, osteopontin, osteocalcin, and bone sialoprotein. RESULTS: There were statistically significant differences between the groups in relation to mRNA levels for MMP-2 (TG=3.26±0.89; CG=4.23±0.97; p=0.01), TIMP-2/MMP-2 ratio (TG=0.91±0.34; CG=0.73±0.32; p=0.04), OPG (TG=0.84±0.45; CG=0.30±0.26; p=0.001), and OPG/RANKL ratio (TG=0.60±0.86; CG=0.23±0.16; p=0.04), favoring the TG. CONCLUSION: The present data suggest that the aPDT associated to nonsurgical and surgical periodontal therapy may modulate the extracellular matrix and bone remodeling by up regulating the TIMP- 2/MMP-2 and OPG/RANKL mRNA ratio, but the clinical relevance needs to be evaluated in further studies.

Comparison between micro- and macrosurgical techniques for the treatment of localized gingival recessions using coronally positioned flaps and enamel matrix derivative.

BACKGROUND: The aim of this study is to compare the macro- and microsurgery techniques for root coverage using a coronally positioned flap (CPF) associated with enamel matrix derivative (EMD). METHODS: Thirty patients were selected for the treatment of localized gingival recessions (GRs) using CPF associated to EMD. Fifteen patients were randomly assigned to the test group (TG), and 15 patients were randomly assigned to the control group (CG). The microsurgical approach was performed in the TG, and the conventional macrosurgical technique was performed in the CG. The clinical parameters evaluated before surgery and after 6 months were GR, probing depth, relative clinical attachment level, width of keratinized tissue (WKT), and thickness of keratinized tissue (TKT). The discomfort evaluation was performed 1 week postoperative. RESULTS: There were no statistically significant differences between groups for all parameters at baseline. At 6 months, there was no statistically significant difference between the techniques in achieving root coverage. The percentage of root coverage was 92% and 83% for TG and CG, respectively. After 6 months, there was a statistically significant increase of WKT and TKT in TG only. Both procedures were well tolerated by all patients. CONCLUSIONS: The macro- and microsurgery techniques provided a statistically significant reduction in GR height. After 6 months, there was no statistically significant difference between the techniques regarding root coverage, and the microsurgical technique demonstrated a statistically significant increase in WKT and TKT.