PDT and Periodontal Treatment in DMT2 Patients

Randomization of the patients to the different groups will be performed with the appropriate software program. Only the lead researcher will have access to the randomization list. Allocation to the two groups will be carried out in blocks of four.

The patients will be sent to Operator A for the periodontal exam. Without knowledge of the results of this exam, the patients will be treated by Operators B and C for periodontal treatment, which will involve oral hygiene instructions as well as supra-gingival and sub-gingival scaling and planing in up to four sessions. At the end of each session, the patients will be sent to Operator D, who will administer either placebo or active PDT based on the content of the sealed envelope. Thus, both the patients and operator in charge of the periodontal exams will be blinded to the PDT protocol (double-blind study).

Fasting blood sugar and glycated hemoglobin exams will be performed at baseline as well as 15, 30, 90 and 180 days after the completion of treatment. All exams will be carried out at the same laboratory affiliated with the university.

The clinical periodontal exams will be performed by a single examiner specialized in periodontics, who will evaluate six regions of each tooth with a 15-mm probe (North Carolina model, Hu-Friedy, Chicago, IL, USA). The following aspects will be recorded: plaque index, bleeding upon probing, probing depth, gingival recession and attachment loss (Armitage, 2004). Evaluations will be carried out performed at baseline (prior to initial treatment) as well as 15, 30, 90 and 180 days after the completion of treatment.

Patients will receive periodontal treatment and photodynamic therapy (active or sham depending on the allocation).

Crevicular fluid will be collected from the previously defined sites with a probing depth equal to or greater than 4 mm that will receive treatment. Collection will be performed with relative isolation using cotton rolls following the removal of supra-gingival plaque with periodontal curettes and air drying for five seconds. Absorbent paper strips (PerioPaper, ProFlow Inc., Amityville, NY, USA) will be individually inserted into each site for 30 seconds (Rudin et al., 1970). The collections will be performed by a single researcher. The volume of crevicular fluid samples will be measured using the Periotron 8000 micro-moisture meter (Oraflow Inc., NY, USA). The samples will then be placed in duly identified sterile plastic microtubes, temporarily stored in dry ice and subsequently stored in a freezer at -80 ºC

Inclusion criteria

• Compensated type 2 diabetes mellitus or with adequate control based on the criteria of the Brazilian Society of Diabetes (SBD, 2012);
• Chronic periodontitis (AAP, 2001);
• Presence of at least 15 teeth and at least four teeth with bleeding upon probing and probing depth greater than 4 mm;
• Aged 18 years or older;
• Under follow up with an endocrinologist.

Exclusion criteria

• Uncompensated diabetes, based on SBD criteria;
• Smoking habit in 12 months prior to treatment;
• Anemia;
• Active cancer;
• Current pregnancy;
• History of antibiotic therapy in previous six months;
• History of anti-inflammatory therapy in previous three months;
• Clotting disorder (use of anti-coagulant, presence of liver disease, thrombocytopenia and immunosuppression);
• Currently undergoing orthodontic treatment.