Photobiomodulation of Orthodontic Mini-implants by a 635nm Diode Laser

The mini-implants stability was estimated employing a Periotest device (Medzintechnik Gulden e K, Modautal, Germany). The Periotest measurement system includes the sound formed from contact between an object and a metallic tapping bar in a handpiece, which is electromagnetically driven and electronically verified. The Periotest response detection is analyzed through a fast Fourier transform (FFT) algorithm. Simply put, the Periotest answer to tapping is estimated by an accelerometer and then analyzed. The signal generated by tapping is then transformed to a value called the Periotest value (PTV), which depends on the damping characteristics of the peri-implant tissue. [27] The Periotest Test values (PTVs) are based on a numerical scale ranging from -8 to +50, defined by mathematical computation. The lower Periotest values indicate higher implant stability and thereupon the higher absorption effect of the target objects.

Immediately after the mini-implants placement, each patient received a questionnaire for individual pain assessment (the numeric rating scale, NRS-11, grade level 0-10). The maximum pain level was measured at both sides of the maxilla during the first day after the treatment. The NRS-11 scale consists of a conscious, subjective assessment of the pain experienced; therefore, it is used in the case of patients over ten years old. A rating of 0 signifies no pain, 1-3 represents mild pain, 4-6 moderate pain, and 7-10 severe pain.