Red light therapy, also known as low-level laser therapy (LLLT), has also been shown to have a significant bactericidal potential without causing damage to the oral tissues. This effect has been documented both in vitro, on diverse microbial species, and in vivo, in the treatment of gingivitis, periodontitis and other oral diseases.
LLLT has been proposed to increase bone remodeling and tooth movement with the benefits like decreased pain and inflammation, collagen stimulation, and cell proliferation.
Long-term orthodontic treatment is a major concern for patients, and reducing this time requires an increase in orthodontic tooth movement. One meta-analysis demonstrated that RLT significantly increased the orthodontic tooth movement of human canine in the patients compared with the controls after 21 days, one month, 1.5 months, two months, three months, & 4.5 months.
Microbial infection plays an important role in persistent periapical lesions. Insufficient disinfection of root canals would lead to treatment failure and persistent periapical pathology. Factors such as anatomical complexities, bacterial growth as biofilm, render complete disinfection of the root canal system almost impossible.
E. faecalis is a gram positive anaerobic coccoid, which is more resistant to mechanical instrumentation and irrigation with antimicrobial agents and has the ability to adapt to the harsh environmental condition in instrumented and medicated root canals.
Gram-negative bacteria are less susceptible to photoinactivation than gram-positive species. Furthermore, RLT significantly reduces the counts of E. faecalis in infected root canals compared to traditional endodontic instrumentation/irrigation treatment protocols; however controversial results have been reported.
Advantages of RLT include immediate effects, selectivity, access to complex areas such as furcation, pits over the root, decreasing the possibility of bacteremia in immunocompromised systemic patients, decreasing dentin sensitivity after root planning, decreasing patient discomfort, pain, and edema after surgery, low cost and time saving and avoidance of interfering with normal flora of adjacent tissues. Furthermore, it has low toxicity and causes minimal damage to host tissue.
Studies reporting the effectiveness of alternative treatments like diode lasers for dentin hypersensitivity have been appearing with increasing frequency. Reduction of hypersensitivity at seven days achieved by LLLT suggests the need for long-term, large sample-sized clinical studies in order to better understand the performance of RLT when compared to desensitizer applications. However, the advantages and limitations of RLT treatments for clinical use have not yet been fully clarified.
Pesevska S and colleagues compared low level laser and fluoride therapy and observed complete resolution of pain achieved in 86.67% of the laser-treated group, compared to 26.67% of the control group with topical fluoride treatment. (1)
Researchers have shown that the use of the diode lasers at wavelengths in the visible and near-infrared regions may lead to an increase in the resistance of teeth against demineralization (enamel erosion). (2)
"The results of this research show that photodynamic therapy (PDT) could be an effective supplement in root canal disinfection. PDT using LED lamp was more effective than diode laser 810nm in reducing CFUs of E. faecalis in human teeth." (3)
"Based on the findings of the present study, it can be concluded that LLLT is an effective modality for the treatment of aphthous ulcers (canker sores). Not only does LLLT reduce the healing time, it also provides immediate pain relief." (4)
"The LLLT can speed up the rate of tooth movement of human canine and consequently decrease the treatment time. LLLT represents a proper adjuvant therapy for fixed orthodontic treatment." (5)
This study suggests that RLT with LED lights provides a significant further reduction in CFU (colony-forming units) counts after irrigation with NaOCl and can serve as an effective method in reducing the bacterial load within the root canal system. (6)
"Reduction of hypersensitivity at 7 days achieved by LLLT suggests the need for long-term and large sample-sized clinical studies in order to better understand the performance of this treatment when compared to desensitizer applications." (7)
"LLLT had an inhibitory effect on typical oral microbial biofilms, and this capacity can be altered according to the interactions between different species." (8)
"Conclusion: LLLT is effective in the treatment of denture stomatitis." (9)
**While the current scientific research seems to indicate many positive benefits of RLT in relation to oral health pathologies, there is still an appreciable necessity for more extensive research to be conducted in this area, including double-blind RCT (randomized controlled trials), to provide a more comprehensive, robust overview that will further elucidate the optimal parameters & appropriate uses of RLT, which will ultimately lead to the most safe & efficacious uses for individuals dealing with oral health impairments.