Kinga Grzech-Leśniak: Microbiological Outcomes Following the Combined Use of Nd:YAG and Er:YAG Laser in Non-Surgical Periodontal Therapy - A Randomized Controlled Clinical Study
Objectives: The aim of the present study was to microbiologically evaluate the outcomes following non-surgical periodontal therapy by either a combination of Nd:YAG and Er:YAG laser or by Er:YAG laser alone.
Materials and methods: Forty patients diagnosed with generalized chronic periodontitis were randomly assigned to one of two treatment groups:
NdErNd group: Nd:YAG laser (Fotona, LightWalker) for pocket disinfection (MSP, 2.5 W, 20 Hz, 300 m fiber tip,10 to 30s per tooth) followed by root debridement with Er:YAG laser (Fotona LightWalker) (MSP, 40 mJ/p, 40 Hz, 400 m fiber tip, water spray) and subsequent application of
Nd:YAG fiber tip, 10 to 30s per tooth). Repetition of Nd:YAG treatment alone (i.e. without any further debridement with Er:YAG laser) at 7 and 14 days (MSP, 2.5 W, 20 Hz, 300 m fiber tip, 10 to 30s per tooth).
Er group: root debridement with Er:YAG laser alone (MSP, 40 mJ/p, 40 Hz, 400 m fiber tip, water spray). The following microbiological parameters were recorded at baseline and 6 months after treatment by means of molecular-biological tests that apply the real-time PCR method (polymerase chain reaction).
Results: Both therapy modalities resulted in a reduction of the total bacteria count after 6 months. In particularly, with red complex bacteria, a huge decrease was detected in the number of Tannerella forsythia: in the NdErNd group from 3.9x105 (n=20; SE=9.7x104) at baseline to 3.2x104 (n=20; SE=2.9x104) after 6 months; in the Er group from 3.6x105 (n=19; SE=9.9x104) at baseline to 7.1x104 (n=19; SE=3.0x104) after 6 months. In the case of Treponema denticola, a significant reduction of bacteria was observed in the NdErNd group from 3.0x105 (n=20; SE=9.5x104) at baseline to 1.4x104 (n=20; SE=2.2x104); and in the Er group from 2.4x105 (n=20; SE=9.5x104) at baseline to 6.2x104 (n=20; SE=2.2x104) after 6 months. The number of Porphyromonas gingivalis decreased significantly only in the NdErNd group from 1.9x107 (n=20; SE=1.3x107) at baseline to 1.8x105 (n=20; SE=1.2x105) after 6 months. On the contrary, the number of Aggregatibacter actinomycetemcomitans decreased significantly only in the Er group from 2.9x103 (n=20; SE=1.6x103) at baseline to 95.0 (n=20; SE=67.1) after 6 months. The NdErNd treatment reduced the number of all tested bacteria of orange complex (Pi, Pm, Fn, Cg and En) after 6 months while the Er:YAG laser reduced only Pm, Fn and En in the same period.
Conclusions: Within the limits of our study it can be concluded that the combination of Nd:YAG and Er:YAG laser in non-surgical periodontal treatment results in superior microbiological outcomes in comparison to Er:YAG laser treatment alone.
