Pulp Preservation, a New Principle, a New Norm:Part II The Use of Laser in VPT

The preservation of natural dentition has become a primary goal of modern pulp therapy, shifting the "restorative cycle" away from early extraction and toward minimally invasive interventions (1).Vital Pulp Therapy (VPT) aims to maintain the health and function of the remaining radicular pulp when the coronal portion is compromised by caries or trauma (1). One of the most significant recent improvements to this discipline is the application of laser technology, which offers unique advantages in disinfection, hemorrhage control, and the stimulation of biological repair. (2)

The Biological Rationale for Laser Application

Lasers (Light Amplification by Stimulated Emission of Radiation) emit coherent, monochromatic, and collimated light that concentrates energy on target tissues. In the context of the dental pulp, laser irradiation has three primary therapeutic effects (3).

1. Decontamination: Lasers offer a non-pharmaceutical approach to achieving a sterile zone, which is essential for the success of VPT. They have more advantages than the pharmaceutical approach (fig 1)can effectively ablate the smear layer and destroy bacteria in deep dentin layers. (4)
2. Hemostasis: Effective hemorrhage control is a key indicator of pulpal health; lasers achieve this by sealing small blood vessels through thermal coagulation, creating a dry field without the need for aggressive chemicals. (3)

Fig 1: decontamination using pharmaceutical approach

 

3. Biostimulation: Laser energy promotes the proliferation of human dental pulp fibroblasts and increases the synthesis of collagen and osteocalcin, leading to the formation of a reparative dentin bridge. (1)
4. Postoperative Comfort: A common complication following VPT is postoperative hypersensitivity, particularly to cold. Photobiomodulation (PBM) , formerly known as low-level laser therapy (LLLT), uses visible red or near-infrared light with low power to stimulate healing without thermal or ablative mechanisms. PBM (fig 2) significantly decreases postoperative sensitivity and pain by altering the behavior of neuronal cell membranes and reducing the production of pro-inflammatory mediators. Clinical studies have shown significant reductions in cold sensitivity at 6 hours, 24 hours, and up to 30 days post-treatment when PBM is applied.(4-6)

Types of Lasers in VPT

Different laser systems are utilized based on their specific wavelengths and absorption characteristics in water, hemoglobin, and hydroxyapatite.

 

1. Diode Lasers (810–980 nm): These are widely used for soft tissue surgery and are highly absorbed by pigmented tissues like hemoglobin and melanin, making them excellent for blood coagulation and hemostasis. They are semiconductor lasers utilized for decontamination in endodontics.

• Advantages: Diode lasers are compact, portable, and lower in cost compared to other systems. They provide excellent hemostasis because they are highly absorbed by hemoglobin and melanin, which facilitates the migration of fibroblasts for dentinal bridge formation.
• Disadvantages: They have little absorption in dental hard tissues, which limits their use to soft tissue manipulation. Prolonged exposure (over 3–5 seconds) or high power outputs can cause regressive changes or necrosis in the pulp.(1,7)

2. Erbium Lasers (Er:YAG and Er,Cr:YSGG): These wavelengths match the infrared absorption peak of water, allowing them to ablate both hard and soft tissues with minimal thermal damage.(4) Erbium lasers has the ability to induce explosive ablation of tissue.

• Advantages: They are the only lasers capable of ablating both hard and soft tissues with minimal thermal damage, making them ideal for cavity preparation and caries removal. Unlike rotary drills, they do not produce dentinal debris, maintaining a more sterile environment.
• Disadvantages: They have limited hemostatic ability compared to CO2 or diode lasers because their thermal effect is extremely low. Furthermore, their shallower penetration depth (100–300 µm) means they are less effective at deep disinfection than Nd:YAG systems.

3. CO2 Lasers (9,300–10,600 nm): These lasers are rapidly absorbed by water and hydroxyapatite, making them efficient for rapid tissue ablation and achieving deep hemostasis through thermal effects (4). These far-infrared lasers are highly absorbed by water and hydroxyapatite, making them efficient for soft tissue applications.

• Advantages: They provide strong hemostasis by sealing small blood vessels through thermal coagulation, which creates a dry field for capping materials (fig 3). Histologically, they promote the synthesis of heat shock protein-47 (HSP47) and collagen, which are vital for reparative dentin formation.
• Disadvantages: CO2 lasers carry a high risk of carbonization and crack formation in hard tissues like dentin if not used with precise cooling. The equipment is often bulky and may lack the flexible fiber-optic delivery systems found in other lasers.

Fig 3: Total heamostasis accomplishment in capping procedures for preparation of capping material application.

4. Nd:YAG Lasers (1,064 nm): Known for their high penetration depth and excellent bactericidal effects, these lasers are often used for deep disinfection and coagulation (4). The Nd:YAG laser emits near-infrared light that is deeply absorbed by pigmented tissues and hemoglobin.

• Advantages: It features a high penetration depth (3–5 mm), providing superior disinfecting ability and effective hemostasis. It is delivered via thin, flexible optical fibers, allowing for easy access to the pulp chamber.
• Disadvantages: Due to its high absorption in pigments, it can cause hazardous temperature rises and pulpal necrosis if parameters are not strictly controlled. It often requires the application of a black dye to the target area to ensure energy absorption, which is technique-sensitive.

 

5. Photobiomodulation (PBM / LLLT): Unlike the high-power lasers above, PBM uses low-energy light (visible red or near-infrared) to trigger photochemical reactions.

• Advantages: It is a secure, non-invasive technique that significantly reduces postoperative pain and hypersensitivity to cold. It enhances wound healing by increasing mitochondrial ATP synthesis and stimulating stem cell proliferation.
• Disadvantages: PBM is inadequate as a standalone therapy; it must be combined with a biocompatible capping material like MTA or Biodentine to achieve a biological seal. Additionally, improper dosing (too high or too low energy density) can fail to stimulate or even inhibit cellular activity. (5,6)

Influence of Capping Materials

Clinical trials comparing different methodologies suggest that the combination of laser Vital therapies and MTA (fig 4) yields some of the best results in primary teeth, showing high success rates in both clinical and radiographic parameters. However, it is vital to optimize laser parameters—such as output power, exposure time, and pulse frequency.(4,8)

Fig 4: MTA Application on vital pulp therapy

 

Conclusion

Laser technology is no longer "science fiction" but a reliable, non-invasive technique to improve patient comfort and enhance the biological success of vital pulp therapy. By providing superior decontamination and stimulating the pulp’s innate regenerative capacity, lasers are helping to establish a new norm in tooth-saving procedures.

 

 

REFERENCES

 

1. Simonoska, J., Bjelica, R., Dimkov, A., Simjanovska, J., Gabrić, D., & Gjorgievska, E. (2025). Efficacy of Laser Pulpotomy vs. Conventional Vital Pulpotomy in Primary Teeth: A Comparative Clinical Analysis. Children, 12(3). https://doi.org/10.3390/children12030341
2. Afkhami, F., Rostami, G., Xu, C., & Peters, O. A. (2024). The application of lasers in vital pulp therapy: clinical and radiographic outcomes. BMC Oral Health, 24(1). https://doi.org/10.1186/s12903-024-04026-x
3. Komabayashi, T., Ebihara, A., & Aoki, A. (2015). The use of lasers for direct pulp capping. In Journal of Oral Science (Vol. 57, Issue 4, pp. 277–286). Nihon University, School of Dentistry. https://doi.org/10.2334/josnusd.57.277
4. Afkhami, F., Rostami, G., Xu, C., Walsh, L. J., & Peters, O. A. (2023). The application of lasers in vital pulp therapy: a review of histological effects. In Lasers in Medical Science (Vol. 38, Issue 1). Springer Science and Business Media Deutschland GmbH. https://doi.org/10.1007/s10103-023-03854-7
5. Angolkar, Y. S., Kulkarni, S., Yavagal, C. M., Yavagal, P. C., Bhosle, U., Patil, V. C., Almalki, S. A., Gowdar, I. M., & Gufran, K. (2024). Effect of Laser Photobiomodulation on Postoperative Pain After Single-Visit Endodontic Treatment in Children: A Randomized Control Trial. Children, 11(12). https://doi.org/10.3390/children11121511
6. Olszewska, A., Matys, J., Gedrange, T., Paszyńska, E., Roszak, M. M., & Czajka-Jakubowska, A. (2024). Evaluation of photobiomodulation for postoperative discomfort following laser-assisted vital pulp therapy in immature teeth: A preliminary retrospective study. Advances in Clinical and Experimental Medicine, 33(7), 709–716. https://doi.org/10.17219/acem/171812
7. Yasuda, Y., Ohtomo, E., Tsukuba, T., Okamoto, K., & Saito, T. (2009). Carbon dioxide laser irradiation stimulates mineralization in rat dental pulp cells. International Endodontic Journal, 42(10), 940–946. https://doi.org/10.1111/j.1365-2591.2009.01598.x
8. Czajka-Jakubowska A. Evaluation of photobiomodulation for postoperative discomfort following laser-assisted vital pulp therapy in immature teeth: A preliminary retrospective study. Adv Clin Exp Med. 2024;33(7):709–716. doi:10.17219/acem/171812