Introduction

Cosmetic dentistry is founded on the fundamental principles of facial and oral aesthetics, enabling clinicians to fulfill patients’ aesthetic expectations while achieving optimal clinical outcomes. These principles identify three essential components that determine smile beauty: teeth, gingiva, and lips [1]. The harmonious interplay of these elements creates an aesthetically pleasing smile that evokes positive emotional and psychological responses.

When this aesthetic harmony is lacking, gingival modifications to height, thickness, and contour may be required to achieve optimal results. A classic example is the gummy smile, characterized by exposure of ≥ 2 mm of gingival tissue above the fully visible maxillary anterior teeth. In such cases, gingivectomy—with or without accompanying osteotomy—represents the treatment of choice [2–4]. Gingivectomy is further indicated for multiple clinical scenarios, including: treatment of gingival enlargement; facilitating access to sound tooth structure margins; prosthetic indications such as crown lengthening; and various cosmetic enhancements including gingival reshaping, contour modification, and gingival zenith point adjustment [5, 6]. Additionally, gingivectomy may be indicated in orthodontics—for example, to improve oral hygiene, facilitate bracket placement, or expose superficially impacted teeth [7, 8].

The supracrestal tissue attachment (STA) represents the primary determinant of gingival margin position following gingivectomy procedures [9]. Other factors should be taken into account, including the width of attached gingiva and the position of the cementoenamel junction [10], and the gingival margin’s relationship to both the tooth’s long axis and incisal edge, as well as its aesthetic alignment with the lip line and adjacent teeth [11]. Clinicians should always consider both the potential for gingival margin changes following crown lengthening procedures and the required stabilization period for these margins, which is generally estimated to be at least six months—particularly when planning anterior esthetic restorations [12–14].

The primary modalities for performing gingivectomy include surgical scalpels, electrosurgery, and lasers [15]. Scalpel gingivectomy offers several advantages: ease of execution, precise incisions with well-defined margins, rapid wound healing, and absence of lateral tissue damage. However, this technique typically induces significant intraoperative bleeding, necessitating periodontal dressing placement—a requirement that patients may find uncomfortable [16].

Extensive clinical evidence demonstrates that the use of lasers for soft tissue procedures offers a valuable alternative to conventional scalpel surgery. In orthodontic applications, laser-assisted gingivectomy serves multiple purposes: enhancing oral hygiene and bracket placement, improving gingival aesthetics, and facilitating exposure of superficially impacted teeth. This approach may additionally reduce postoperative discomfort and potentially shorten overall treatment duration [8, 17].

Laser technology offers superior surgical control, reduced postoperative pain/analgesic requirements, minimal inflammation, excellent hemostatic properties, and suture-free wound healing [8]. However, its primary limitations include higher costs and longer procedural times compared to conventional methods. Multiple laser systems are clinically available, including carbon dioxide (CO₂), diode, neodymium-doped yttrium aluminum garnet (Nd:YAG), and erbium-doped yttrium aluminum garnet (Er:YAG) lasers [18]. These lasers differ in terms of their absorption within the tissue, which is related to the wavelength, power, laser spot size, exposure time, and pulse repetition rate (frequency). In addition to other tissue-specific parameters including, absorption and scattering coefficients, tissue thickness, heat capacity, and thermal conductivity [19].

In the past, non-contact ablative lasers (including CO₂ and erbium systems) have been used for oral soft tissue surgery. In orthodontic practice, diode lasers are now preferentially employed for incision/excision procedures. Compared to scalpel techniques, diode lasers maintain a clean surgical field with superior hemostasis, while offering the added benefit of photobiomodulation—enhancing wound healing and significantly reducing postoperative patient discomfort [17].

In dental practice, what is the effect of using a laser for gingivectomy on treatment efficacy and safety, compared to conventional surgical methods, both during and after the procedure?

Materials and methods

This article was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, PRISMA, guidelines [20] and has been registered at the International Prospective Register of Systematic Reviews (PROSPERO) under number CRD42024501110.

Results

Results of the electronic literature search

A flow diagram of the selection process is shown in Figure 1. The search strategy yielded 1,896 results in the four databases. During the pre-screening phase, 26 duplicate records were removed. Following deduplication, 1,870 records underwent title and abstract screening, resulting in the exclusion of 1,769 irrelevant studies. Of the remaining 101 potentially eligible studies, 7 were unavailable for retrieval.

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Figure 1. Flow chart of included study

Note. Adapted from “The PRISMA 2020 statement: an updated guideline for reporting systematic reviews” by Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. BMJ. 2021;372:n71 (https://doi.org/10.1136/bmj.n71). CC BY.

Ninety-four studies were screened by full-text reading, as a result, 22 articles met our inclusion criteria, in which gingivectomy was performed for several indications such as clinical crown lengthening (CCL), gingival enlargement, altered passive eruption, restorative and esthetic purposes.

Fifteen of the included studies were RCTs, and seven were non-randomized studies. The RCTs varied in design: eight followed a parallel-group design, four used a split-mouth design, two employed a stratified sampling design, and one utilized a split-mouth crossover design.

All included studies compared various laser types with conventional surgical methods (using either a traditional scalpel or an electrosurgical blade).

Risk of bias assessment

Risk of bias in randomized studies was assessed using the RoB 2 tool developed by Cochrane. Among the 15 RCTs, the final overall judgment indicated:

• 1.

  4 studies had a low risk of bias.

• 2.

  7 studies had some concerns.

• 3.

  4 studies had a high risk of bias.

Specifically:

• 1.

  2 studies were rated as high risk in the randomization process.

• 2.

  2 studies were rated as high risk due to missing outcome data (Figure 2).

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Figure 2. The risk of bias in randomized studies

The risk of bias in non-randomized studies was assessed using the ROBINS-I tool, and the final overall judgment of the 7 included studies resulted in all studies being of low risk of bias except one study of moderate risk (Figure 3).

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Figure 3. The risk of bias in non-randomized studies

Discussion

Numerous studies have shown that the use of lasers for soft tissue procedures provides an alternative adjunct to traditional scalpel surgery. Laser-assisted gingivectomy is utilized in orthodontics to enhance oral hygiene and bracket placement, improve gingival aesthetics, and expose superficially impacted teeth, potentially reducing post-operative pain and decreasing the duration of orthodontic treatment [8, 17].

This systematic review provides a comprehensive synthesis of current evidence on the efficacy and safety of laser-assisted gingival resection. The analysis encompassed 22 clinical studies, including 15 RCTs and 7 non-randomized clinical studies, offering a substantial evidence base for clinical evaluation.

The methodological assessment revealed significant heterogeneity in study quality. Among RCTs evaluated using the Cochrane RoB 2 tool (n = 15), approximately 27% (4/15) demonstrated low risk of bias, 47% (7/15) raised some concerns, while the remaining 27% (4/15) were classified as high risk. The critical appraisal identified specific methodological limitations: 13% (2/15) of studies exhibited deficiencies in randomization procedures, and an equivalent proportion (2/15) were compromised by incomplete outcome data. These findings reflect well-documented challenges in surgical trial methodology, where practical constraints often impede proper allocation concealment and follow-up adherence.

In contrast, non-randomized studies assessed via ROBINS-I demonstrated comparatively stronger methodological quality, with 86% (6/7) rated as low risk and only 14% (1/7) showing moderate risk of bias.

Pain is often the most significant concern for patients during and after treatment, as it results from the activation of the nervous system and induces a sensation of discomfort. The concept of discomfort expresses the psychological and emotional aspects of the patient; however, it is not definitively associated with pain [47].

The inherent challenges in achieving patient blinding in surgical studies necessitate meticulous environmental control by researchers to ensure objective pain assessment and minimize confounding variables. Current evidence from numerical rating scales (NRS) demonstrates generally reduced pain perception in laser-treated groups [25–29], except for Nd:YAG laser procedures which showed increased discomfort [30, 31]. Laser techniques consistently demonstrated superior patient satisfaction with reduced analgesic requirements compared to conventional surgery [25–31, 33, 34]. However, multiple confounding factors—including variations in anesthetic protocols (depth, type, and administration), the potential for pain transference in split-mouth designs, and the inherently subjective nature of pain perception—collectively preclude definitive conclusions regarding laser superiority in pain control, despite these observed favorable trends.

Studies have unanimously agreed on the superiority of almost all types of lasers in bleeding control compared to the scalpel during and after surgery. Intraoperative hemostasis provides a clear and dry surgical field that makes it easier to see, in addition to a greater ability to access the targeted tissue [48]. The persistent hemostatic effect of laser treatment was evident postoperatively, typically eliminating the need for additional bleeding control measures. However, histological analyses revealed significant variations among laser systems: Er:YAG and Er,Cr:YSGG lasers demonstrated minimal to absent hemostasis at tissue margins, in contrast to the pronounced hemostatic effects observed with CO₂ and 810 nm diode lasers. This disparity was similarly reflected in coagulation layer thickness—while erbium-family lasers produced thin marginal coagulation zones, CO₂ and diode lasers generated substantially thicker coagulated layers [36, 49]. The reduced thickness of both coagulation and thermal effect layers results from water-cooled systems that limit temperature elevation within tissues, consequently diminishing hemostatic efficacy [49]. Paradoxically, two additional studies reported minimal bleeding with flapless Er,Cr:YSGG osteotomy and gingival excision compared to both open-flap Er,Cr:YSGG laser techniques and traditional flap methods [25, 26].

Regarding the need for the use of surgical sutures, laser sites showed a clear superiority as they did not need any surgical sutures unlike the scalpel and the traditional flap [25, 26, 29, 37].

The surgical technique and the difference in the targeted chromophores may affect the short-term outcomes, and procedure-related morbidity and contribute to the advantages and limitations of each laser type [26]. In addition to other complications, such as causing allergic reactions, which lasted for four weeks [40].

Although the diode 808–810 and diode 940 lasers in general have approximate wavelengths to that of the Nd:YAG laser, they do not seem to cause the same complications according to the included studies, and for their high hemostasis capacity, however, their relatively deep tissue penetration, and they should be used at the lowest effective power setting to minimize side effects. This also applies to other lasers, as it seems unjustified to use the Nd:YAG laser with a power of 7 Watts [40]. When the same laser can cut with a power of 1.25–3 Watts as mentioned in White’s study [31]. Therefore, the practitioner must start with the lowest effective power for cutting and gradually increase it if it was proven to be ineffective, according to the thickness of the cut tissue and its statement (healthy/inflammatory/fibrous...). Using inappropriate parameters will also lead to undesirable side effects as increasing the exposure time, which will increase the risk of laser penetration into the tissue and thermal collateral damage.

The Er:YAG laser demonstrates exceptional precision in soft tissue excision, combining high water affinity with integrated cooling to achieve minimal penetration depth. This results in clean surgical margins with negligible thermal damage, surpassing conventional methods in tissue preservation [36]. Its unique dual capability for both soft tissue procedures and osteotomy presents a promising area requiring further high-quality clinical investigation Similarly, the Er,Cr:YSGG laser exhibits comparable clinical performance, with parameter-adjusted efficacy for both soft and hard tissue applications. This versatility stems from its ability to exploit the differential absorption characteristics of various tissue types [25].

The included studies demonstrate equivalent gingival margin stability between Er,Cr:YSGG laser techniques (flapless/open-flap) and conventional scalpel procedures at both 3-month [25] and 9 months [26] postoperative evaluations. Since the most substantial margin alterations occur during the initial three-month healing phase [41], clinicians must observe a mandatory ≥ 3-month healing period to ensure complete tissue reorganization before permanent restoration placement [26]. Furthermore, periodontal phenotype constitutes a critical determinant of healing outcomes, with thick biotypes exhibiting superior gingival margin stability and more predictable rebound characteristics compared to thin phenotypes [26].

In addition, achieving stable and predictable crown lengthening outcomes requires greater bone reduction with a more coronal flap positioning [48]. However, the characteristically limited hemostatic capacity of erbium-family lasers remains a critical consideration when selecting appropriate laser systems for these procedures.

The CO₂ laser demonstrates dual advantages of precise tissue incision with minimal marginal rupture and superior hemostatic/coagulation capacity [36]. However, its lack of integrated cooling systems elevates thermal injury risks, potentially explaining the comparable recovery periods observed across diode 808/980 nm, Nd:YAG, and conventional scalpel techniques [33, 39, 42]. Current evidence remains limited by insufficient high-quality studies establishing reproducible laser parameters.

Given both the procedural versatility of multiple laser systems and the notable research gaps—particularly for CO₂, Er:YAG, and Er,Cr:YSGG modalities—no single laser platform currently emerges as definitively superior for gingival resection procedures.