Efficacy of Carbon Dioxide Laser in Treating Oral Lichen Planus-A Scoping Review

1. Postgraduate Student, Department of Oral Medicine and Radiology, Rajas Dental College and Hospital, Tirunelveli, Tamil Nadu, India. 2. Professor and Head, Department of Oral Medicine and Radiology, Rajas Dental College and Hospital, Tirunelveli, Tamil Nadu, India. 3. Senior Lecturer, Department of Oral Medicine and Radiology, Rajas Dental College and Hospital, Tirunelveli, Tamil Nadu, India. 4. Reader, Department of Oral Medicine and Radiology, Rajas Dental College and Hospital, Tirunelveli, Tamil Nadu, India. 5. Reader, Department of Oral Medicine and Radiology, Rajas Dental College and Hospital, Tirunelveli, Tamil Nadu, India.

Abstract

Introduction: Oral Lichen Planus (OLP) is a chronic disorder and its aetiology is multifactorial. Factors like local and systemic inducers of cell-mediated hypersensitivity, stress, autoimmune response and viral infection play a major role. Due to the varying aetiological factors, there are varying treatment modalities. With systemic medication, remission of the lesion is the most common side-effect.

Aim: To determine the efficacy of carbon dioxide laser in treating OLP.

Materials and Methods: In this systematic review, the study was done between January 2022 to April 2022 at Rajas Dental College and Hospital, Tamil Nadu. Search categories were specifically followed to databases like PubMed, PubMed Central, Cochrane, Medline, Embase and in Google Scholar. MeSH terms like CO₂ Laser, OLP, Carbondioxide Laser and Oral Premalignant Condition were used for searching the articles.

Results: A total of 942 articles had been collected. But after analysing the articles, only 16 articles based on the preformed inclusion and exclusion criteria had been selected. Out of these three were retrospective studies, five were prospective studies, one clinical trial, one observational study and one study was a Randomised Control Trial (RCT), one was a non RCT, one was a structured abstract, one was a single arm intervention study, one was a case series, and one was a case report.

Conclusion: Carbon dioxide laser was very efficient in treating larger size lesions. Recurrence rate of the lesions was very less when treated at an early stage.

Autoimmunity, Gas, Lasers, Oral

Lichen Planus (LP) was first described by Dr. Erasmus Wilson in 1869. It was originally named “Lichen Ruber Planus” and “Lichen Psoriasis”. Oral Lichen Planus (OLP) is a chronic disorder with a primary role in the immune system (1),(2),(3). Oral lesions may or may not manifest as skin lesions. OLP affects 0.5% to 2.2% of the population. The aetiology is still unknown. It has a female predilect. Middle-aged individuals are the most affected. The exact prevalence is unknown, but it has been estimated to be between 0.5% and 2.6% in various populations (4),(5). In most OLP cases, the patient is usually unaware of the oral condition. Patients may complain of roughness/burning in the lining of the mouth, red or white patches or ulceration (6),(7). Due to the unclear aetiology of OLP, the results of managing LP are also not satisfactory. Remission of the lesion is the main drawback. Carbon dioxide (CO₂) laser is one of the earliest gas lasers invented by Kumar Patel of Bell Labs in 1964. Because of its cutting efficiency, it remains a desirable choice in facial cosmetic surgeries (8). Since they have less tactile sensation when compared to the other lasers, they are not preferred for hard-tissue procedures. They are mainly used for soft tissue surgical procedures (9). In the 1980s, these lasers were used for the management of oral leukoplakia. Laser surgery is considered superior when compared to conventional systemic drug therapy, cold instrumentation, and electrocautery (10). Since there was very few evidence-based information on the topic of treating OLP using CO₂ laser (2), the systematic review was aimed to find the efficacy of CO₂ laser in the treatment of OLP.

Material and Methods

The systematic review is registered in the PROSPERO with the registration Id CRD42022298392. The study was done between January 2022 to April 2022 at Rajas Dental College and Hospital, Tamil Nadu. A detailed systematic search of the literature was done from the databases of PubMed, PubMed Central, Cochrane Library, Medline, Embase and finally, a random search was also done in Google Scholar. The articles were searched between the timeline 1980 to 2022. The following MeSH keywords “OLP, oral premalignant condition, CO₂ laser, carbon dioxide laser” were used for the search in the above databases. The Boolean logic “AND” was used between CO₂ laser and OLP. It yielded more results than other keyword combinations in the database. MeSH terms like CO₂ laser AND OLP yielded 262 articles in PubMed, 257 articles in PubMed Central, and 83 articles in Cochrane.

From the systematic search, a total of 942 results were obtained from the above databases and the references to the above articles were also considered, if they were relevant to the review. Out of 942, 30 articles were also obtained from Google Scholar and back references.

Inclusion criteria: It included original articles, all clinical studies including RCT, cohorts, case-control, case reports, case series, systematic reviews, and free articles. In case where free articles were not available, the articles with structured abstracts were considered, articles about CO₂ laser in treating OLP, and articles that were only in English.

Exclusion criteria: Review articles about CO₂ laser in treating OLP and oral leukoplakia, newsletters, letters to the editor, articles with non structured abstracts, treatment of OLP and oral leukoplakia other than CO₂ lasers, and usage of CO₂ laser other than oral cavity.

Based on the above inclusion and exclusion criteria, the articles obtained were filtered. A total of 61 articles were relevant. On further analysing the articles, due to the irrelevant content, 15 full articles and one structured abstract were finally selected and rest were excluded. The articles were assessed using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol in the systematic review. Three reviewers analysed every article. Blinding was not done. The conclusion was formulated after a detailed discussion with the panel of reviewers.

Results

A total of 942 articles were identified by searching the databases like PubMed, Pubmed Central, Cochrane Library, Medline, Embase, and Google Scholar. 697 articles were excluded after screening the title and 210 were excluded after reading the abstract due to their irrelevant nature. 19 articles were excluded after full reading because the content did not meet the inclusion criteria of the study (Table/Fig 1). A total of 926 articles were excluded and therefore 16 articles (11),(12),(13),(14),(15),(16),(17),(18),(19),(20),(21),(22),(23),(24),(25),(26) were selected for further analysis. This included one structured abstract, one clinical trial (11),(12); out of which three were retrospective studies (21),(23),(25), five were prospective studies (13),(15),(19),(20),(22), and other studies, like observational study (14), RCT (24), non RCT (18), single-arm intervention study (26), case series (16), and case report (17), which had one article each (Table/Fig 2) (11),(12),(13),(14),(15),(16),(17),(18),(19),(20),(21),(22),(23),(24),(25),(26).

Summary of benefits of using CO₂ laser: There was a significant reduction in pain and lesion size in subsequent follow-up periods (11). The healing following laser removal progressed well (12). After CO₂ laser therapy in the dorsum of the tongue, instead of a denuded

tongue, the papilla started to reappear in the affected areas (13). The re-epithelialisation was complete at all wound sites in 7-14 days and healing occurred without any complication (14). The laser-treated mucosa returned to the same colour as the surrounding mucosa (15). The case series concluded that the CO₂ laser was safe and more efficient to use against OLP but the cost of the CO₂ laser made it less affordable (16).

Summary of advantages of CO₂ laser over conventional scalpel treatment in treating OLP: The comparison of CO₂ laser and conventional scalpel procedure in treating OLP was studied in an animal model. The animal model had advantages like minimal damage to the adjacent tissues, less inflammatory reaction and fewer myofibroblasts, which resulted in little wound contraction. It was more efficient when compared to a scalpel in terms of the large lesion due to the bloodless field (17),(27).

The postoperative effects on pain, bleeding and swelling were reduced when compared to the conventional scalpel. Since the lesions were subepithelial, the depth of invasion to eradicate the lesion was sufficient in the vaporisation technique. The immunologic status was altered for the better of the patient (18),(28). The case report reported that the amount of myofibroblasts was more in the case of CO₂ laser treatment when compared to scalpel excision (19).

Summary of advantages of CO₂ laser over systemic and topical corticosteroids: The size of the lesion and pain level showed no changes in both the groups of corticosteroids and CO₂ laser. But at the end of the study, the efficiency level of laser therapy was higher than that of systemic corticosteroids. The size of the lesion and the pain level decreased in the case of CO₂ laser therapy (20).

Summary of modes of CO₂ lasers: The total number of articles included in this category was two. Three different modes of CO₂ laser were used in the vaporisation of premalignant lesions. The modes were Continuous Wave (CW) defocussed, CW scanner, and Super Pulse (SP) scanner. Studies have proved that CW defocussed mode was found effective in treating a premalignant lesion in recurrent cases and long-term follow-up was also found successful (21),(22).

Summary of rate of recurrence of OLPOLPOLP when treated with CO₂ laser: The rate of recurrence was high when treated with a CO₂ laser because only the recalcitrant cases were treated with a CO₂ laser. But the rate of malignant transformation was less (23). The patients who were treated with the defocussed mode in CO₂ laser therapy showed a lesser recurrence rate and lower malignant transformation when compared to patients who received analgesics and steroids (24).

Summary of other lasers: The total number of articles collected under this category was 2. The other lasers like Nd: YAG and LLLT laser were also found to be effective in treating OLP.

The Nd: YAG laser shared many of the advantages of the CO₂ laser, but its unique feature was that it could be utilised in both a contact excision and non contact coagulation mode. Lesions with a small surface area were most efficiently treated with Nd: YAG laser as it has a very precise contact mode of delivery. The recurrence rate of OLP when treated with Nd: YAG laser was also very less when compared to CO₂ laser (25).

LLLT has a property called laser biomodulation. It can change the cell function, non thermally and non destructively. It has additional benefits when compared to CO₂ laser by simultaneously applying infra-red and red light to affect the surface and depth of the lesion. It has a low recurrence rate and is easier and less time-consuming (26).

Discussion

LP is a common chronic inflammatory mucocutaneous disorder that typically affects the skin and mouth (29). The major aetiological factors of OLP are local and systemic inducers of cell-mediated hypersensitivity, stress, autoimmune response, and viral infections. The foremost treatment starts with topical and systemic corticosteroids. For biopsy purposes, incisional/excisional biopsy with a scalpel is performed under local anaesthesia to make a confirmatory final diagnosis (30).

In recent years, laser treatment has come into existence to give immediate symptomatic relief in patients with a burning sensation. Various lasers have been used in recent years, like CO₂ laser, Nd: YAG laser, LLLT, Argon laser, Diode laser, Ho: YAG laser, and Er: YAG laser. The choice of laser depends mainly upon the precision and depth of tissue ablation, haemostasis, effectiveness in a fluid-filled environment, and any preference for the pigmented surface (31).

The systematic review was made in such a way to prove the efficacy of the CO₂ laser in treating OLP. Initially, meta-analysis was also planned since we obtained heterogeneous types of studies, but was not performed. All the RCT and non RCT, observational clinical studies, case reports, cohort studies, prospective, and retrospective study were included and the review articles were excluded.

The heterogeneous nature of studies started from the size and duration of the lesion, follow-up period, a recalcitrant or fresh case of OLP, mode of CO₂ laser, the wavelength of CO₂ laser, duration of CO₂ laser contact with the tissue, and the brand of the laser machine. The patient’s psychological status also paves a big path (20).

The CO₂ laser has two methods to remove the lesion. They are vaporisation of the surface mucosa and excision of the lesion. Vaporisation was done in inaccessible areas such as the floor of the mouth. Excision was done with the removal of soft tissue lesions with underlying tissues. This creates a slightly deeper wound. The CO₂ laser has a standard wavelength of 10,600 nm and for soft tissue surgeries it has another variant of 9300 nm. The CO₂ laser machine has 3 modes, defocussed mode, SP mode and scanner mode. The defocused mode shows great efficacy when compared to the other modes in treating OLP. In case of vaporisation, the beam will be in contact with the tissues for a minimum of 4 minutes. Keeping in contact with the tissues for a longer time would result in thermal injury and burrowing wounds (21),(22).

The CO₂ laser has proved efficient when compared to conventional systemic and local corticosteroids and conventional scalpel excision of the lesion. The corticosteroids show remission of the lesion within a short period whereas the CO₂ laser in long-term follow-up doesn’t show remission of the lesion (19). CO₂ laser has few advantages over corticosteroids and conventional scalpel surgery. They can be used to excise larger lesions with the bloodless field of surgery and minimal wound contraction. Postoperatively they show less pain and a faster healing phase (19).

Studies have stated that the lesions occur in other areas which were not exposed to the laser tip (14). Some cases show recurrence even after treatment with CO₂ laser because of the underlying systemic disorder.

Since the CO₂ laser has a non contact mode, they cannot refine the cutting areas. They also have a larger beam and it is cost-effective (21). This is the major disadvantage of using CO₂ laser. To overcome these disadvantages Nd: YAG laser and LLLT laser came into existence. Nd: YAG laser has the additional advantage of using it as a non contact and contacts laser which is used in vaporisation and excision respectively (23). LLLT has the advantage of dealing with smaller lesions particularly when the lesion is near the tooth surface area approximating gingiva since it has a smaller size beam. But still, long-term follow-up is necessary to prove the scenario (24).

Limitation(s)

Since, the articles which were included in the study were heterogeneous in nature (different varying data), the meta-analysis could not be performed. The lack of RCT clouds the result of this systematic review.

Conclusion

The OLP is a chronic mucocutaneous disorder and it has a multifactorial aetiology. CO₂ laser is the best when large lesions are treated because of the large beam. Small lesions can also be treated but it affects the normal mucosa. The vaporisation technique proves effective in treating OLP. CO₂ laser proves efficient in treating recalcitrant cases when compared to systemic and topical corticosteroids and conventional scalpel surgery. Hence, CO₂ laser treatment can be given as a first line of therapy even before the use of corticosteroids. Additionally, treating the underlying systemic disorder and stress reduction may lead to the complete cure of the lesion.

DOI and Others

DOI: 10.7860/JCDR/2023/59161.17572

Date of Submission: Jul 19, 2022
Date of Peer Review: Sep 05, 2022
Date of Acceptance: Oct 22, 2022
Date of Publishing: Mar 01, 2023

AUTHOR DECLARATION:
• Financial or Other Competing Interests: None
• Was Ethics Committee Approval obtained for this study? No
• Was informed consent obtained from the subjects involved in the study? No
• For any images presented appropriate consent has been obtained from the subjects. No

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ETYMOLOGY: Author Origin