Comparison of the Results of Biostimulation Treatment of Inferior Alveolar Nerve Injury Using Nd:YAG and Diode Lasers With Different Wavelengths.

NCT07416006 | Completed

• 1 other identifier: 2023000457-3
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

Intraoral surgical procedures such as sagittal split osteotomy, dental implant placement, and surgical extraction of third molars are widely performed interventions in oral and maxillofacial surgery. Although these operations are generally safe and predictable, they may cause direct or indirect injury to the inferior alveolar nerve, one of the main sensory nerves of the mandible responsible for the innervation of the lower teeth, alveolar bone, gingiva, lower lip, and chin. Damage to this nerve can occur due to mechanical trauma, compression, thermal injury, or stretching during surgery, as well as following facial or mandibular trauma. As a consequence, patients may experience various neurosensory disturbances such as anesthesia, hypoesthesia, paresthesia, or dysesthesia. These conditions often result in discomfort, reduced functional capacity, and psychological distress, affecting both esthetic and functional expectations after surgical recovery. Restoring normal nerve function in such cases remains a major clinical challenge in oral surgery and neuromodulation research. The inferior alveolar nerve follows a delicate anatomical path through the mandibular canal, where it is easily affected by surgical manipulations. Even minor trauma may lead to transient or permanent sensory dysfunction. The pathophysiology of such nerve injuries involves axonal degeneration, demyelination, and subsequent alterations in nerve conduction. Depending on the severity, nerve regeneration may occur spontaneously or may require therapeutic intervention. The degree of recovery depends on the extent of axonal disruption, the inflammatory response in the surrounding tissue, and the capacity of Schwann cells to facilitate remyelination. Traditional treatment approaches for inferior alveolar nerve injury include observation, pharmacological support, surgical decompression, or microsurgical repair. However, outcomes of these methods are often unpredictable, and recovery is slow. Therefore, noninvasive therapeutic modalities that can enhance neuronal healing and accelerate sensory recovery have become an area of increasing interest in modern dentistry and maxillofacial surgery. Among these, the use of laser biostimulation-also known as low-level laser therapy or photobiomodulation-has gained significant attention as a noninvasive, safe, and clinically applicable method to promote nerve regeneration. Laser biostimulation involves the application of light energy at specific wavelengths to biological tissues, leading to a cascade of photochemical and photophysical effects at the cellular level. When absorbed by mitochondrial chromophores, particularly cytochrome c oxidase, the photons increase cellular metabolism, enhance ATP synthesis, stimulate DNA and RNA synthesis, and promote cellular proliferation and differentiation. In neural tissues, this process can lead to activation of Schwann cells, enhancement of neurotrophic factor secretion, reduction of oxidative stress, and modulation of inflammatory mediators, thereby creating a favorable microenvironment for axonal regrowth. Consequently, photobiomodulation represents an advanced therapeutic approach to accelerate neural healing following both iatrogenic and traumatic nerve injuries. Two of the most commonly used laser types for biostimulation in clinical practice are diode and Nd:YAG lasers. Both operate in the near-infrared region of the electromagnetic spectrum but differ in wavelength, absorption characteristics, and depth of tissue penetration. The diode laser emits light typically between 800 and 1000 nanometers, with the 980-nanometer wavelength being one of the most widely used in dentistry. Its energy is well absorbed by melanin and hemoglobin, making it particularly effective in soft-tissue applications, wound healing, pain modulation, and superficial tissue regeneration. The Nd:YAG laser, operating at 1064 nanometers, has a longer wavelength that allows deeper tissue penetration. It is less absorbed by superficial pigments and more effective in reaching submucosal, muscular, and neural tissues. The differences in penetration depth and absorption profiles mean that while diode lasers are efficient for surface-level biostimulation, Nd:YAG lasers are more suited for stimulating deeper anatomical structures such as nerves and bone.

Conditions

Inferior Alveolar Nerve Injury; Neurosensory Disturbance; Paresthesia and Hypoesthesia; Nerve Regeneration; Photobiomodulation Therapy; Nd:YAG Laser Biostimulation; Diode Laser Therapy; Post-Surgical Nerve Recovery; Oral and Maxillofacial Surgery Complications

Keywords

Inferior Alveolar Nerve Injury; Nerve Regeneration; Photobiomodulation Therapy; Low-Level Laser Therapy (LLLT); Oral and Maxillofacial Surgery; Noninvasive Regenerative Therapy

Outcome Measures

Primary Outcomes (1)

• Change in Subjective Sensory Perception Measured by Visual Analog Scale (VAS)

  This primary outcome assesses participants' subjective perception of numbness, paresthesia, or altered sensation in the lower lip and chin region. Participants will rate their sensory perception using a 10-point Visual Analog Scale (VAS), where 0 represents complete anesthesia (no sensation) and 10 represents normal sensation. Improvement will be defined as an increase in VAS score from baseline to follow-up time points.

  Baseline (pre-treatment), immediately after completion of 3-week treatment, 1 month, 3 months, and 6 months post-treatment

Secondary Outcomes (1)

• Improvement in Neurosensory Function Measured by Two-Point Discrimination (2PD)

  Baseline (pre-treatment), immediately after completion of 3-week treatment, 1 month, 3 months, and 6 months post-treatment

Study Arms (3)

Nd:YAG Laser Group

EXPERIMENTAL

Participants in this arm will receive Nd:YAG laser biostimulation therapy for inferior alveolar nerve injury. The laser operates at a wavelength of 1064 nm with parameters of 0.5 W power and 10 Hz frequency. The application will be performed intraorally and extraorally along the course of the injured nerve region twice per week for three consecutive weeks. Each session will last approximately two minutes. The purpose of this intervention is to evaluate the biostimulatory effect of Nd:YAG laser on neurosensory recovery following intraoral surgery or trauma.

Device: Nd:YAG Laser Biostimulation

Diode Laser Group

EXPERIMENTAL

Participants in this arm will receive Diode laser biostimulation therapy for inferior alveolar nerve injury. The laser operates at a wavelength of 980 nm with parameters of 200 mW power, 10 Hz frequency, and 2 J energy per session. Applications will be performed intraorally and extraorally over the affected mandibular region twice per week for three consecutive weeks. Each session will last approximately two minutes. This arm aims to evaluate the effectiveness of Diode laser photobiomodulation on neural regeneration and sensory recovery.

Device: Diode Laser Biostimulation

Control Group

NO INTERVENTION

Participants in this arm will not receive any active laser treatment. They will undergo the same evaluation schedule and follow-up intervals as the experimental groups. This control arm allows the comparison of natural neurosensory recovery with that achieved by Nd:YAG and Diode laser biostimulation therapies.

Interventions

Nd:YAG Laser Biostimulation DEVICE

Low-level Nd:YAG laser biostimulation applied at 1064 nm wavelength, 0.5 W power, 10 Hz frequency. Treatment performed intraorally and extraorally over the course of the inferior alveolar nerve twice per week for three weeks. Each session lasted approximately two minutes.

Nd:YAG Laser Group

Diode Laser Biostimulation DEVICE

Low-level Diode laser biostimulation applied at 980 nm wavelength, 200 mW power, 10 Hz frequency, and 2 J energy per session. Treatment performed intraorally and extraorally twice per week for three weeks over the injured mandibular nerve area. Each session lasted approximately two minutes.

Diode Laser Group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults aged 18 years or older.
• Patients diagnosed with inferior alveolar nerve injury following intraoral surgical procedures (such as sagittal split osteotomy, implant placement, or third molar extraction) or mandibular trauma.
• Presence of sensory disturbances including anesthesia, hypoesthesia, or paresthesia in the lower lip and chin region.
• Ability and willingness to participate in the study and attend all scheduled follow-up visits.
• Provision of written informed consent prior to participation.

You may not qualify if:

• History of systemic diseases that may affect nerve healing (e.g., diabetes mellitus, neuropathies, autoimmune disorders).
• Current use of medications known to interfere with nerve regeneration (e.g., corticosteroids, neurotoxic drugs).
• Previous laser therapy or photobiomodulation treatment to the same area.
• History of smoking or alcohol abuse.
• Pregnant or breastfeeding women.
• Patients with local infection, malignancy, or open wounds in the treatment area.
• Inability to comply with study procedures or follow-up schedule.

Sponsors & Collaborators

• Ondokuz Mayıs University: lead

Study Sites (1)

Ondokuz Mayıs University, Faculty of Dentistry, Department of Periodontology

Samsun, 55270, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Paresthesia; Hypesthesia

Condition Hierarchy (Ancestors)

Somatosensory Disorders; Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: This clinical study is designed as a single-blind, randomized, parallel assignment trial. The masking strategy in this study primarily applies to the participants, who remain unaware of the type of laser system used during the biostimulation sessions. Masking of participants is implemented to minimize subjective bias in sensory evaluation and to ensure that the perceived or expected benefits of laser therapy do not influence the outcome assessments. The overall goal of this masking approach is to enhance the internal validity of the study by maintaining participant neutrality and preventing placebo or expectation effects from altering the recorded data. At the beginning of the study, all eligible participants are informed that they will receive either a laser treatment or a control procedure. However, they are not told whether the laser used is an Nd:YAG or a Diode laser. Both laser devices are similar in appearance and operation, producing comparable auditory and visual cues such as
• Purpose: SUPPORTIVE CARE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Doctor

Model Details: This study is designed as a randomized, single-blind, parallel assignment clinical trial aimed at comparing the effects of Nd:YAG and Diode laser biostimulation on inferior alveolar nerve (IAN) injury following intraoral surgical procedures and mandibular trauma. The model focuses on evaluating the degree of neurosensory recovery, improvement in tactile discrimination, and reduction in postoperative paresthesia using standardized clinical tests. A total of 30 participants will be included in the study and equally divided into three groups: Nd:YAG laser group, Diode laser group, and Control group without laser treatment. The parallel assignment design allows simultaneous comparison of the two active interventions against a control under identical clinical conditions. The parallel design was selected to ensure that each participant receives only one type of intervention during the entire study period, preventing cross-contamination between treatment modalities and minimizing carryover e

Study Record Dates

• First Submitted: November 27, 2025
• First Posted: February 17, 2026
• Study Start: October 27, 2024
• Primary Completion: October 27, 2025
• Study Completion: October 27, 2025
• Last Updated: February 17, 2026

Record last verified: 2025-11

Locations

TU (1)