Laser Doppler Assessment of Microcirculation of Apical Periodontitis before Nonsurgical and during Surgical Laser Treatment

Introduction: Laser doppler flowmetry is a non-invasive method of measuring microcirculatory blood flow in tissue. Using laser doppler flowmetry Moor VMS-LDF1-HP and CP1T-HP probe combined with Moor VMS-PC software to evaluate the state of the periapical lesion (cyst) before nonsurgical endodontic treatment with bioceramics (Well Root SP™) and compare it to a healthy vital tooth of the same type with no periapical lesions. Later the bony crypt of the cyst was evaluated with Moor VMSLDF1-HP and VP7BS-HP probe during periapical surgery after the cyst was ablated with Er: YAG laser Lite Touch™ (Sineron, Israel) and retrogradely obturated with TheraCal LC®. Then the cyst received a bioceramic bone graft. To our knowledge, this is the first time laser doppler has been used during periapical surgery to evaluate tissue perfusion. Lesion type was confirmed with a histological examination after surgery. Aim: Evaluate tissue perfusion of a periapical lesion before nonsurgical treatment and during surgical endodontic treatment with Er:YAG laser with the help of laser doppler flowmeter. Results: Laser doppler flowmetry shows that the cystic tooth has a decreased blood flow, decreased concentration, direct current, speed, and lower temperature compared to a healthy tooth of the same type. During periapical surgery, the direct laser blood flow evaluation of the surgical crypt shows different values of the flux, speed, direct current, concentration, and temperature, which could be attributed to the mechanical trauma, adrenaline in the local anaesthetic or laser irradiation of tissues. Conclusions: Laser doppler flowmetry is a valuable method to perform tissue evaluation before, during and after treatment. It allows us to follow up the healing and pathological dynamics of microcirculatory tissue changes as well as evaluate and compare different methods and materials for treatment of apical periodontitis.