Treatment of experimental periodontal disease using aPDT with nanoparticles

Objectives: The aim of this study was to histologically and histometrically evaluate the influence of antimicrobial Photodynamic Therapy (aPDT) associated to nanoparticles on bone loss in furcation areas in rats with experimentally induced periodontal disease.  

Methods: Periodontal disease was induced by placing a ligature around the first mandibular molar in seventy-two rats. After 7 days, the ligature was removed. The animals were divided into four groups: the SRP group received scaling and root planning (SRP); the Methylene Blue group (MB) received SRP as well as Methylene Blue (MB);   the aPDT group received SRP as well as MB and low level laser therapy (LLLT; InGaAlP, 660 nm; 4.94 J/cm²/point, 0.035 W); the aPDT/N group  received  SRP as well as MB associated to Au/Ag nanoparticles and LLLT and six animals in each group were sacrificed at 7, 15 and 30 days. The area of bone loss in the furcation region of the first molar was histometrically analyzed. Data were analyzed statistically with an analysis of variance and Tukey’s test; significance was set at P<0.05.

Results: Histometric analysis showed less bone loss in the aPDT (0.55±0.14; 0.54±0.21; 0.55±0.26) and aPDT/N (0.58 ± 0.084;  0.60 ± 0.10;    0.47 ± 0.12) groups than in the SRP group (2.17±0.54;  1.66±0.28;  1.38±0.30)  at 7, 15 and 30 days, respectively (P<0.05). The MB group showed less bone loss than SRP group at 7 and 15 days. No significant differences were found between the aPDT and aPDT/N groups (P>0.05).

Conclusions: When compared to SRP, aPDT and aPDT/N was an effective adjunctive treatment for induced periodontitis in rats. The addition of Au/Ag nanoparticles to MB did not improve bone loss reduction.