This study tests whether using an Er,Cr:YSGG laser before applying numbing gel (lidocaine) can help reduce pain during dental procedures compared to traditional methods. Investigators want to know:

Does the laser make the numbing gel work better and longer?

Does it lower pain and keep patients calmer (measured by heart rate)?

Investigators enrolled 20 adults (10 men, 10 women) and assigned them to three groups:

Laser + Numbing Gel: Laser was used on the gums before applying lidocaine.

Sham Laser + Numbing Gel: A fake laser was used with lidocaine.

Sham Laser + Vaseline: A fake laser was used with Vaseline (no numbing effect).

Participants reported pain levels on a scale (0=no pain, 10=worst pain) when a tiny needle touched their gums. Investigators also checked their heart rate.

Participants will be invited to participate in a study observing the anesthetic efficacy of the combination of Er,Cr:YSGG laser and surface anesthetic agent on the oral mucosa. This informed consent form provides participants with detailed information to help participants decide whether to participate in this project. Please read it carefully. If participants have any questions, please raise them to the researcher in charge of the study. Investigators will give participants a comprehensive explanation.

Participants' participation in this study is voluntary. This research has been reviewed by the ethics committee of this research institution.

Research purpose: By measuring the anesthetic depth of the combined use of Er,Cr:YSGG water laser and surface anesthetic agent at different time points in the oral vestibule of the mandibular anterior teeth area, to observe the anesthetic efficacy of the combined use of Er,Cr:YSGG water laser and surface anesthetic agent on the oral mucosa.

Research content and process: Before participants are selected for the study, the doctor will ask about participants basic situation, record participants' medical history, and conduct a routine oral examination. The specific requirements are: no allergy to anesthetic drugs, no mucosal lesions, no pregnancy, no systemic diseases, and good health condition.

If participants' above examinations are qualified, participants will follow the following steps for the study: Rest for half an hour to stabilize blood pressure and heart rate. The nurse will put an electrocardiogram monitor on participants to record the changes in blood pressure and heart rate throughout the process. The doctor will select three sites in the vestibule of the mandibular anterior teeth area and irradiate 1 cm away from the site at a 90-degree angle with water laser or ineffective laser for 1 minute, and then randomly apply lidocaine or vaseline to the three sites. The subjects will not rinse their mouths during the experiment. The doctor will insert an aseptic needle into the mucosa at three sites in the mandibular anterior teeth area 10 minutes, 20 minutes, 30 minutes, 40 minutes and 50 minutes after irradiation, and the subjects will raise their hands to indicate "feeling" or "pain" to stop the needle insertion. The doctor will record the depth of needle insertion.

After the anesthesia, the doctor will check the wound. The doctor will visit the subject's numbness and record the anesthetic duration. Observe whether there are itching, pain, redness and swelling in the wound.

Risks and discomforts: A few people in this clinical experiment may have discomfort symptoms such as itching, pain, and redness. If these discomforts occur, the doctor will handle them promptly. Participants' relevant information will be kept confidential. Investigators will do our best to minimize the possibility of participants' information being exposed.

Benefits of participating in this study: Participants will receive a free panoramic X-ray, full-mouth examination, and supra-gingival scaling.

Cost: The relevant research costs for this project will be borne by the research group. Participants do not need to bear the relevant costs for the research process itself, and it will not increase participants' additional medical treatment costs. If physical harm is caused to participants due to the research itself, the additional medical treatment costs will be compensated or compensated in accordance with relevant national laws and regulations.

As a research subject, participants need to: Provide the true situation of participants' own medical history and current physical condition; Tell the researcher of any discomforts participants experience during this study; Tell the researcher whether participants have participated in other studies recently or are currently participating in other studies, and other matters that may affect the research results or participants' health.

Privacy issue: If participants decide to participate in this study, participants' participation in the trial and participants' personal information during the trial will be kept confidential. Participants' identity information will not be disclosed to members outside the research group unless participants give participants' permission. All research members and the research sponsor are required to keep participants' identity confidential. Participants' file will be stored in a locked filing cabinet and only available for researchers to consult. To ensure the research is conducted in accordance with regulations, when necessary, members of government management departments or ethics review committees will be able to consult participants' personal information at the research institution. When the research results are published, no personal information of participants will be disclosed.

Participants have the right to choose not to participate in this study. During the research process, participants also have the right to withdraw at any time without any reason. Investigators will decide whether the obtained data will be included in the research results according to participants' wishes and the needs of the research. Participants' any rights will not be affected in this case.

If participants need other treatments, or participants fail to follow the research plan, or there is any injury related to the research or any other reasons, the researcher can terminate participants' participation in this study.

Participants can always obtain information about themselves and the progress of this research. If participants have any questions related to this research, or if participants experience any discomfort or injury during the research process, or if participants have any questions regarding the rights of participants in this study, please contact the researcher by phone or other means in a timely manner.

Inclusion Criteria:

• could understand and follow given instructions

Exclusion Criteria:

• excessive dental anxiety
• anesthesia allergies
• mucosal lesions
• cardiovascular disease
• diabetes
• pregnancy or lactation
• severe psychiatric disorders
• hearing abnormalities
• speech dysfunction

from enrollment until end of follow-up, up to 1 week