The Effect of Photobiomodulation on Inflammation Levels and Stability Following Dental Implantation: A Randomised, Single-Blind, Controlled Study

Dental implants offer a high success rate as the most up-to-date treatment method for replacing lost teeth. However, whilst implants have emerged as the ideal treatment for tooth loss, the incidence of postoperative complications-including postoperative oedema, wound infection, and early dehiscence or perforation of the soft tissue flap-has also increased. The soft tissue surrounding the implant forms a strong barrier to prevent bacteria and metabolic by-products from entering deeper tissues and colonising the implant surface. Complications related to soft tissue can negatively affect implant success by leading to bacterial invasion in the early stages. Therefore, the rapid establishment of effective soft tissue sealing is crucial for establishing and maintaining the health of peri-implant tissues. Consequently, the search for a method capable of supporting the healing of soft tissues around the implant is a significant area of research in modern dental implantology. The primary stability of dental implants is defined by the biomechanical stability achieved during implant placement. The quantity and quality of the residual bone are key determinants of primary stability. The process continues with secondary stability, during which osseointegration is expected. As osseointegration requires complete structural and functional bonding between the living tissue and the implant surface, it is influenced by numerous factors. Low-level laser therapy or photobiomodulation (PBM) has been proposed as a method that may support osseointegration by reducing healing time in preclinical and clinical studies.

PBM involves the use of light across a broad wavelength range from red to infrared to produce analgesic, anti-inflammatory and biological stimulation effects. Different wavelengths are selected depending on the desired effect. The 660 nm wavelength (red light) increases adenozin tri phosphate (ATP) production, which provides energy for cellular repair and regeneration, and alters mitochondrial membrane potential. It also aids tissue healing by promoting collagen synthesis. The 808 nm wavelength (near-infrared light) penetrates deeper into tissues, reducing inflammatory responses by regulating reactive oxygen species and cytokine levels. There is no specific guideline regarding which wavelength of PBM should be applied for osseointegration and soft tissue healing. In this study, drawing on similar studies, two different wavelengths were examined to demonstrate the described effects. Resonance frequency analysis (RFA) is recognised as a commonly used and reliable method for measuring the stability of dental implants. RFA analysis is performed using specialised devices containing a 'smart pin' placed in the implant or abutment to quantify stability numerically. The implant stability quotient (ISQ) is presented using a numerical scale ranging from 0 to 100, and a higher ISQ value indicates better overall stability.

Following dental implant surgery, patients exhibit varying degrees of inflammatory signs. Among these signs, pain typically peaks 24 to 72 hours after surgery and then gradually subsides in a physiological manner. Pain is a significant parameter affecting the patient's quality of life and is a finding that must be considered when monitoring the process. For this reason, our study includes measurements of the Healing Index (HI), Modified Sulcus Bleeding Index (mSBI), and Gingival Index (GI), as well as Visual Analogue Scale (VAS) scores.

The aim of this clinical, prospective, comparative study is to evaluate the effect of 808 nm diode laser PBM on implant stability using RFA measurements, and the effect of 660 nm diode laser PBM on inflammation, pain, and postoperative healing.