The Effect of Er,Cr:YSGG Laser-assisted Topical Anesthetic on Oral Mucosal Anesthesia
Phase: EARLY_PHASE1
Conditions: Anesthesia
Sponsor: Li Zhen Zhong

Study Protocol and Statistical Analysis Plan 
 
Official title: The effect of Er,Cr:YSGG laser-assisted topical anesthetic on oral 
mucosal anesthesia 
NCT number: NCT07169032 
Document date: 12/25/2023 
 
 
 
 
 
 
 
 
 
 
 
 
 

This study is a randomized controlled clinical trial with a single-blind design. The 
protocol has been approved by the Medical Ethics Review Committee of Jinan 
University (Approval No.: JNUKY-2023-0149). All participants will provide written 
informed consent before the study begins. 
1. Study Participants 
The study will be conducted in an outpatient setting, with a total of 20 participants (10 
males and 10 females). Participants will be recruited through online advertisements 
and from among outpatient clinic visitors. All participants will receive free oral health 
examinations and related treatments as compensation. 
1.1 Inclusion Criteria 
• 
Aged 20–45 years; 
• 
Able to understand and follow verbal and written instructions. 
1.2 Exclusion Criteria 
• 
Severe dental anxiety; 
• 
Allergy to local anesthetics; 
• 
Presence of oral mucosal lesions; 
• 
History of cardiovascular disease; 
• 
History of diabetes; 
• 
Pregnant or lactating women; 
• 
History of severe psychiatric disorders; 
• 
Hearing or speech impairments. 
2. Group Allocation 
This is a single-blind randomized controlled trial. After providing informed consent, 
participants will be stratified by gender. Three sites in the mandibular anterior 

vestibular groove will be selected and randomly assigned to one of the following three 
interventions: 
• 
Experimental group: Irradiation with Er,Cr:YSGG water laser (wavelength 2780 nm, 
power 1.0 W) for 1 minute, followed by application of 2% lidocaine gel; 
• 
Control group: Irradiation with placebo laser (0.1 W) for 1 minute, followed by 
application of 2% lidocaine gel; 
• 
Blank group: Irradiation with placebo laser (0.1 W) for 1 minute, followed by 
application of petroleum jelly. 
All procedures will be performed by the same operator and assistant. Participants will 
be blinded to group assignment. 
3. Materials and Equipment 
3.1 Experimental Equipment 
3.1.1 Water Laser Device 
Device: Er,Cr:YSGG Waterlase (Model MDX300), manufacturer: BOOLASE (USA), 
registration number: National Medical Device Approval 20153241177. The laser 
wavelength is 2780 nm and is suitable for various dental procedures. Two modes are 
predefined: 
• 
Mode 1a (active laser): Power 1.0 W, water 15%, air 35%, frequency 30 Hz, H mode 
(soft tissue mode); 
• 
Mode 1b (placebo laser): Power 0.1 W, other parameters same as Mode 1a. 
All personnel must wear laser protective glasses during operation. The handpiece 
must be moved continuously to avoid localized heat accumulation. 
3.1.2 Electrocardiogram (ECG) Monitor 

Device: Baolaite M7000 Multi-parameter Monitor (Guangdong Medical Device 
Approval 2012 No. 2210328), used for continuous monitoring of heart rate, blood 
pressure, and oxygen saturation. The cuff is placed on the upper arm, and the oxygen 
sensor is attached to the index finger. Data will be recorded throughout the procedure. 
3.1.3 Visual Analog Scale (VAS) 
A 10 cm linear VAS will be used to assess pain intensity, ranging from "no pain" (0) 
to "worst pain imaginable" (10). Participants will slide the indicator to reflect their 
subjective pain level, and the operator will record the corresponding value. 
3.2 Experimental Drugs and Materials 
• 
Topical anesthetic: 2% lidocaine gel (Gandermal, Registration No.: H20150426); 
• 
Placebo: Petroleum jelly; 
• 
Other materials: 27G injection needle (Fukada), periodontal probe (Hu-Friedy), 
mouth prop (Ivoclar), dental mirror, sterile cotton swabs, timer, etc. 
4. Outcome Measures 
Primary outcome measures include: 
• 
Penetration depth and VAS score at the moment of "sensation of foreign body"; 
• 
Penetration depth and VAS score at the moment of "pain"; 
• 
Heart rate at each needle insertion and the increase in heart rate (heart rate at pain 
moment – baseline heart rate). 
• 
Penetration depth is calculated based on the exposed length of the needle (penetration 
depth = 30 mm – length outside the mucosa). 
5. Study Procedure 
5.1 Preparation Phase 
• 
Participants will rest for 30 minutes after signing consent to stabilize vital signs; 

• 
Baseline heart rate will be recorded. Laser protective glasses and ECG monitoring 
devices will be worn; 
• 
The operator will preset the laser device parameters. 
5.2 Experimental Procedure 
• 
Three sites in the maxillary anterior vestibular groove with intervals >20 mm will be 
selected; 
• 
Interventions will be applied in random order (laser irradiation and subsequent drug 
application); 
• 
Penetration tests will be performed at 10, 20, 30, 40, and 50 minutes after treatment. 
Penetration depth, VAS score, and heart rate will be recorded at the moments of 
"sensation" and "pain"; 
• 
Adverse reactions (redness, pain, bruising, etc.) will be assessed immediately after the 
procedure and at 24-hour follow-up. 
6. Statistical Analysis 
• 
Data will be analyzed using SPSS 27.0. Normally distributed continuous variables 
will be expressed as mean ± standard deviation (x̄  ± s); 
• 
Repeated measures ANOVA will be used to compare differences across time points 
and groups. If the sphericity assumption is violated, multivariate tests (Roy’s Max 
Root) will be applied; 
• 
Pairwise comparisons will be performed using Bonferroni correction with 
significance level α = 0.05; 
• 
A p-value < 0.05 will be considered statistically significant