The association of
doxycycline and periodontal treatment in non-controlled
diabetes mellitus (DM) has shown positive results on clinical and metabolic parameters. Antimicrobial
photodynamic therapy (aPDT) is a local and painless antimicrobial treatment that can be applied in periodontal treatment without systemic risks. The aim of this study was to evaluate the potential improvement of aPDT on clinical and metabolic effects in patients with
type 2 diabetes mellitus in conjunction with nonsurgical periodontal treatment plus
doxycycline. Thirty patients with
type 2 diabetes and diagnosis of
chronic periodontitis were treated with scaling and root planning (SRP; N = 15) or SRP plus
phenothiazine chloride photosensitizer-induced aPDT (SRP + aPDT, N = 15). Patients of both groups took
doxycycline (100 mg/day) for 2 weeks and plaque index,
bleeding on probe (BOP), probing pocket depth (
PPD),
suppuration, clinical attachment level (CAL), and
glycated hemoglobin levels (HbA1c) were measured at baseline and 3 months after
therapy. An improvement in clinical parameters such as
PPD, CAL, S, and BOP between groups was observed but without statistical significance (p > 0.05). Intragroup analysis showed a significant reduction of HbA1c (8.5 ± 0.9 to 7.5 ± 0.1, p < 0.01) in the SRP + aPDT group. The differences of HbA1c between baseline and 3 months were greater for the SRP + aPDT (11.4 %) than SRP (10 %) (0.87 ± 0.9 and 0.4 ± 0.84 respectively; p < 0.05). A single application of the aPDT as an adjunct to periodontal treatment did not show additional benefits in the clinical parameters but resulted in a slight greater decrease in HbA1c.