ATP	adenosine triphosphate
BOP	bleeding on probing
CAL	clinical attachment level
CI	confidence interval
CIs	confidence intervals
CINAHL	Cumulative Index to Nursing and Allied Health Literature
CRP	C-reactive protein
DM	diabetes mellitus
DNS	Diabetic Neuropathy Symptom score
FPG	fasting plasma glucose
GBI	gingival bleeding index
GCF	gingival crevicular fluid
GI	gingival index
GRADE	Grading of Recommendations Assessment, Development and Evaluation
HbA1c	glycated hemoglobin
HRV	heart rate variability
IENFD	intraepidermal nerve fiber density
IL-1β	interleukin-1 beta
IL-6	interleukin-6
ILIB-M	modified intravascular laser irradiation of blood
IQR	Interquartile range
J/cm2	joule per square centimeter
LED	light-emitting diode
LEDT	light-emitting diode therapy
LLLT	low-level laser therapy
MD	mean difference
MIRE	monochromatic infrared energy
MNSI	Michigan Neuropathy Screening Instrument
NDS	Neuropathy Disability Score
Nd:YAG	neodymium-doped yttrium aluminum garnet
NF-κB	nuclear factor kappa B
nm	nanometer
NSPT	nonsurgical periodontal therapy
OGTT	oral glucose tolerance test
PBMT	photobiomodulation therapy
PD	probing depth
PI	plaque index
PICOS	Population, Intervention, Comparison, Outcomes, and Study design
PPD	probing pocket depth
PRISMA	Preferred Reporting Items for Systematic Reviews and Meta-Analyses
PROSPERO	International Prospective Register of Systematic Reviews
QoL	quality of life
QoL-DN	Norfolk Quality of Life–Diabetic Neuropathy questionnaire
RBS	random blood sugar
RCT	randomized controlled trial
RCTs	randomized controlled trials
RoB2	Cochrane Risk of Bias tool version 2
SD	standard deviation
SE	standard error
SRP	scaling and root planing
T2DM	Type 2 diabetes mellitus
TNF-α	tumor necrosis factor alpha
VAS	visual analog scale
VO2	oxygen uptake
VPI	visible plaque index
VPT	vibration perception threshold
W	Watt
τ2	between-study variance