Table 2. Parameters and regimens of lasers applied in the included studies.

Study ID	Year	Category	Type of laser	Wavelength (nm)	Output power	Repetition rate	Method of application
Ozcelik et al. [32]	2008	PBMT	Diode	588	4 J/cm2	N/A	Immediately after EMD application, the defect area was irradiated with PBMT for 10 min. PBMT was applied from the outer buccal and lingual surfaces for 5 min each, immediately after suturing, and daily for 5 days.
Braun et al. [28]	2010	HLLT	Er:YAG	N/A	120 mJ/pulse (panel)	10 Hz	The laser was used to remove subgingival biofilm. Maximum irradiation time was set to 2 min per tooth.
Rotundo et al. [29]	2010	HLLT	Er:YAG	2,940	150 mJ/pulse	10 Hz	The application of the laser treatment was performed from coronal to apical direction with an inclination of the conic fibre tip of about 20° under water irrigation.
Slot et al. [36]	2012	HLLT	Nd:YAG	1,064	400 mJ/pulse (panel)	50 Hz	The fibre tip was held in contact with the tissue and aligned parallel to the tooth with water cooling. The laser was applied for no more than 60 sec per site.
Sanz-Moliner et al. [37]	2013	HLLT and PBMT	Diode	810 ± 20	1 W (HLLT) 4 J/cm2 (PBMT)	CW	HLLT was performed to remove all visible epithelium in the inner side of the flap from the free gingival margin to the bottom of the apical aspect of the flap. For PBMT, all surfaces of the flap, inner and outer, exposed bone, and exposed root structures involved in the surgery were irradiated, leading to a total dosage of 4 J/cm2 per surface.
Yilmaz et al. [30]	2014	HLLT	Diode	810	3 W	CW	An external horizontal releasing incision on the vestibular alveolar mucosa and de-epithelialization of the interdental papilla were performed with diode laser.
Ge et al. [31]	2017	HLLT	Er,Cr:YSGG	2,780	1.25 W	30 Hz	The fiber optic head was moved around the periodontal pockets and across the surface of the root furcations, while debris was washed out of the priodontal pockets under water irrigation.
Heidari et al. [33]	2018	PBMT	Diode	940	40 J/cm2	CW	PBMT ware applied to both buccal and lingual surfaces with energy density 40 J/cm2 and the irradiated area was 2.8 cm2. PBMT were performed only during surgery.
Yildiz et al. [34]	2018	PBMT	Diode	810	6 J/cm2	CW	PBMT was applied with output power 0.1 W for 60 sec at recipient sites immediately, 1, 3, 7, and 14 days after surgery.
Isler et al. [35]	2018	PBMT	Diode	970 ± 15	2 W, 5.25 J/cm2	CW	Total irradiation time was 30 sec (6 sec for each point). PBMT was performed immediately, 1, 3 and 7 days after surgery.

HLLT, high reactive-level laser/light therapy; CW, continuous wave; PBMT, photobiomodulation therapy; EMD, enamel matrix derivative