The effectiveness of lasers in treatment of dentinal hypersensitivity, a scoping review on lasers parametes and clinical protocols

Abstract

Background: The clinical application of laser therapy has emerged as an effective therapeutic modality for managing dentin hypersensitivity (DH). This scoping review aimed to evaluate the efficacy of various laser types in treating DH, summarize tooth preparation protocols (pre-,intra-, and post-laser therapy), and analyze optimal laser parameters. Methods: The electronic database (PubMed, Web of Science, Embase, Google Scholar, and Scopus) were searched for English-language studies published between January 2010 and October 2025. Data extraction and quality assessment were performed by independent observers. Results: Out of 765 identified articles, 59 were initially screened, and 25 met the final eligibility criteria. Our findings confirm the clinical efficacy of various laser modalities in mitigating DH. While some studies reported no significant superiority of lasers over conventional desensitizing agents or placebos, the majority suggested that combined modalities yielded superior results, characterized by both rapid onset and long-term stability. Specifically, the application of low-level diode lasers (630–980 nm), Er:Cr:YSGG lasers (at power settings of 0.25 or 0.5 W), and high-power Nd:YAG lasers were identified as effective therapeutic approaches. Conclusion: Both high-power and low-power lasers, including diode lasers at various wavelengths, and different laser parameters are capable of alleviating DH when utilized with optimized output settings. Furthermore, the synergistic use of chemical desensitizing agents in conjunction with laser therapy, particularly low-power lasers, represents a highly effective clinical strategy for the management of DH. Tooth preparation protocols pre-, intra-, and post-laser therapy must be considered.

Introduction

Dentin hypersensitivity (DH) represents one of the most prevalent clinical challenges in dental practice [1]. DH is characterized by a transient, sharp pain elicited from exposed dentin in response to thermal, chemical, tactile, or osmotic stimuli [2]. This sensation must not be attributable to any other identifiable pathological condition, such as dental caries or cracked tooth syndrome [3]. Clinically, DH manifests as the sudden onset of localized or generalized pain affecting one or more tooth surfaces. The condition can significantly diminish patients’ quality of life by restricting dietary choices, oral hygiene maintenance, and interfering with daily activities. Furthermore, inadequate oral hygiene may exacerbate DH and facilitate the progression of secondary oral pathologies [4].

The etiology of DH differs across age groups, in younger populations, it is frequently associated with enamel erosion, whereas in older adults, it predominantly arises from gingival recession and subsequent exposure of dentinal tubules in the cervical and proximal regions, often secondary to periodontal disease or aggressive toothbrushing [5]. The prevalence of DH in the adult population exhibits significant variability, ranging from 8% to 98%, a discrepancy largely attributed to diverse diagnostic methodologies employed in various studies. Notably, prevalence rates can reach as high as 98% among patients with periodontal disease, with peak incidence typically reported between the second and fifth decades of life [6].

Effective management of dentin hypersensitivity (DH) necessitates accurate diagnosis regarding pain severity and localization, alongside the elimination of both predisposing and causative factors [7]. A wide range of treatment options for DH is currently available, including desensitizing toothpastes, potassium-based compounds, glutaraldehyde-based agents, varnishes, strontium chlorides or acetates, resins, oxalates, calcium phosphates, and laser therapy [8]. But achieving predictable, long-term clinical outcomes remains a challenge. This inconsistency is largely attributed to the complex physical and chemical dynamics within the oral environment, which may facilitate the re-exposure of dentinal tubules [9, 10]. Laser therapy was first introduced for the management of tooth sensitivity in 1985 [11]. Scanning electron microscopy (SEM) has demonstrated that high-power lasers possess the capacity to vaporize, melt, and seal dentinal tubules, potentially through the recrystallization of their mineral components [6]. Conversely, low-level lasers (LLLs) exert their effects by modulating chronic inflammatory processes via the activation of sodium-potassium pumps. Furthermore, they may promote the formation of tertiary dentin, thereby occluding tubule orifices and enhancing analgesic, anti-inflammatory, and photobiomodulatory effects [12]. Clinical evidence suggests that laser treatment is well-tolerated, safe, rapid, and relatively painless for patients [3, 6]. Additionally, the synergistic application of lasers in combination with chemical agents, such as fluoride, has emerged as an effective therapeutic strategy for DH control [13].

Recent systematic reviews have reported the efficacy of both high- and low-power lasers in treating DH [2, 3, 5, 6, 13]. However, the most important challenge of laser therapy is the lack of standardized protocols, specifically regarding precise tooth preparation and optimal laser parameters. Consequently, this review aims to evaluate the efficacy of various laser modalities in the treatment of DH and to synthesize current literature regarding tooth preparation protocols (pre-, intra-, and post-laser therapy) and specific laser application parameters.

Methods

Search strategy

To address the research question, “Is laser therapy an effective modality for managing dentin hypersensitivity?” and “What is the clinical protocol for managing dentin hypersensitivity with laser?”, a search was performed across several electronic databases, including PubMed, Web of Science, Embase, Google Scholar, SID, and Scopus. The search was limited to English-language studies published between January 1990 and October 2024. The search strategy employed Boolean operators as follows: `((dentin OR dental OR tooth OR teeth) AND (hypersensitivity OR sensitive)) AND (laser OR photobiomodulation OR photobiostimulation OR PBM) AND ((treatment OR management OR therapy OR dentin tubule occlusion) OR (pain AND (relief OR reduction OR release)))`. To ensure comprehensiveness, a hand search was conducted through conference abstracts, letters, and articles published in leading journals on lasers in dentistry and medical sciences. Furthermore, the reference lists of included studies (cross-referencing) and existing systematic reviews were searched to identify potentially relevant literature.

Eligibility criteria

This study included randomized controlled trials (RCTs), cohort studies, and retrospective studies that evaluated the efficacy of various laser modalities in the management of DH. Exclusion criteria comprised systematic and narrative reviews, case reports, case series, studies without a control group, in vitro laboratory studies, editorials, and expert opinions.

Data extraction

A standardized data extraction form was developed to capture the following parameters: first author, year of publication, sample size, study design, intervention groups, laser parameters (wavelength, power, etc.), tooth preparation protocols (pre- and post-irradiation), methods of DH assessment, adverse events, and principal conclusions.

Results

The study selection process is illustrated in the flowchart in Fig. 1. Based on the electronic search of the databases, 765 articles were identified. Following the removal of duplicates and the screening of titles and abstracts, 59 articles were identified for full-text eligibility assessment. The methodological quality of the selected studies was evaluated using the CONSORT checklist. A total of 34 articles were excluded based on the following criteria: non-randomized controlled trials, quasi-experimental designs, inappropriate study methodologies, in vitro models, absence of a dedicated laser treatment group, lack of a placebo or non-treatment control group, insufficient or non-quantitative data, and the use of DH assessment tools other than the Visual Analogue Scale (VAS) (Table 1). Consequently, 25 studies met all eligibility requirements and were included in this review (Table 2).

Fig. 1.

The flowdiagram of the research method

Table 1.

List of excluded articles

Number	Author and year	Type of laser	Reason for exclusion
1	Ipci et al., 2009	CO2, Er: YAG	Out come not using VAS
2	Zhang et al., 1998	CO2	No control group
3	Mortiz et al., 1998	CO2	No control group
4	Birang et al., 2007	Er: YAG, Nd: YAG	Detailes ralated to age not specified
5	Schwartz et al., 2002	Er: YAG	Out come not using VAS
6,7	Dilsiz et al., 2010 a, b	Er: YAG	Not RCT
8	Aranha et al., 2012	Er: YAG	Incomplete outcome data and Detailes ralated to age not specified
9	Gelskey et al., 1993	He-Ne, Nd: YAG	No control group
10	Yadav et al., 2019	Nd: YAG	Out come not using VAS
11	Tabatabaei et al., 2018	Nd: YAG	Not an RCT
12	Bouche Bel et al., 2018	Nd: YAG	No control group
13	Ozlem et al.,2018	Nd: YAG, Er: Cr: YSGG	Out come not using VAS
14	Lopez et al., 2017	Nd: YAG	No control group
15	Talesara et al.,2014	Nd: YAG	Not an RCT
16	Lopez et al., 2013	Nd: YAG	No control group
17	Ciaramamicoli et al., 2003	Nd: YAG	Not an RCT
18	Gutknecht et al.,1997	Nd: YAG	No control group
19	Lan et al., 1996	Nd: YAG	In- vitro study
20	Kara et al., 2009	Nd: YAG	No control group
21	Moura et al., 2019	Diod	No control group
22	El mobadder et al., 2019	Diod	No control group
23	Praveen et al., 2018	Diod	No control group
24	Dougles et al., 2018	Diod	No control group
25	Lima et al., 2017	Diod	Out come not using VAS
26	Lopez et al., 2015	Diod	No control group
27	Balet et al., 2015	Diod	No control group
28	Femiano et al., 2013	Diod	No control group
29	Aranha et al., 2009	Diod	Incomplete outcome data
30	Tengrangsun et al., 2008	Diod	Not an RCT
31	Sicilia et al., 2009	Diod	Out come not using VAS
32	Corona et al., 2003	Diod	Not a RCT
33	Narayanan et al., 2019	diod	No control group
34	Ehler et al., 2012	Er: Cr: YSGG	No control group

Table 2.

Main characteristics of included articles

Author and year	Type of laser	Laser parameter	Study design	Control group	Pre-procedure management	Post-procedure management	Number of sessions	Interval of sessions	Measured outcome	Evaluation of DH	Side effect	Conclusion
Lund 2013	Diode low-level infrared laser (GaAlAs)	780 nm wavelength; 5 J/cm²; effective optic potency 20 mW; four punctual applications of 10 s each (three cervical points + one root apex); non-contact	Split-mouth	2% sodium fluoride gel and carbomer 940 gel	Occlusal adjustment; diet orientation; standardized oral hygiene instructions; VAS training; professional brushing and flossing; baseline DH assessment using air blast	No food or drink for 30 min after topical applications; routine oral hygiene maintained	Laser: 3 sessions; Fluoride & placebo: weekly applications for 4 weeks	Laser sessions at 72-hour intervals; topical agents applied weekly	Response to evaporative stimulus assessed by VAS and Air Blast	Baseline; 5 min; 7 days; 15 days; 30 days; 90 days	No adverse effects reported	No statistically significant differences among laser, fluoride, and placebo groups; all treatments (including placebo) significantly reduced dentin hypersensitivity over 90 days
Gerschman 1994	GaAlAs diode laser (low-level laser therapy)	Wavelength: 830 nm; Power output: 30 mW (± 10%); Mode: continuous; Energy per session: 1.8 J (30 mW × 60 s); Application: 1 min to tooth apex + 1 min to cervical area; calibrated before each use	Double-blind, randomized, placebo-controlled clinical trial.	Placebo laser (identical, unpowered device)	Strict inclusion/exclusion criteria; baseline DH assessment; subjects instructed to use non-desensitizing dentifrice; one tooth per subject	Continued brushing twice daily with non-desensitizing dentifrice; no additional desensitizing agents	4 sessions	Baseline, 1 week, 2 weeks, and 8 weeks	Dentinal hypersensitivity (tactile and thermal) rated on VAS	Baseline, 1 week, 2 weeks, 8 weeks	Two patients reported transient, reversible pulpal sensation during lasing; no oral irritation or lasting adverse effects	GaAlAs LLLT produced significant reductions in both thermal and tactile DH compared with placebo from week 1 onward; at 8 weeks, thermal sensitivity reduced by 67% and tactile sensitivity by 65%; laser therapy effective and safe
Yilmaz c 2011	Diode laser (GaAlAs, 810 nm)	Continuous mode; 810 nm; 500 mW; 60 s irradiation; 3.5 cm² tip area; energy density 8.5 J/cm²; non-contact (≈ 2 mm); scanning cervical area in overlapping pattern	randomized, double-blind, placebo-controlled, split-mouth clinical study	1) NaF varnish2) Placebo laser3) Placebo NaF varnish (saline)	Periodontal maintenance patients (> 1 year); baseline VAS > 4; exclusion of caries, restorations, recent desensitizing therapy; no desensitizing toothpaste (3 months); no analgesics; oral hygiene standardized	Standardized oral hygiene; NaF group followed short post-application restrictions.	1 (single application)	Not applicable (single visit)	Dentin hypersensitivity assessed using evaporative air stimulus and Visual Analog Scale	Baseline; immediately post-treatment; 1 week; 1 month; 3 months; 6 months	No complications; no pulpal or allergic adverse effects reported	GaAlAs diode laser and NaF varnish both significantly reduced DH immediately vs. baseline and placebo; laser effect was sustained up to 6 months, whereas NaF showed relapse at 3–6 months; laser more durable than NaF
Ortiz 2019	Diode laser (Photobiomodulation, PBM)	Infrared diode laser, 808 nm; 60 J/cm² per point; 16 s per point; 2 application points per tooth (cervical region and middle third of crown); device: Photon Laser III (DMC, USA) + CPP-ACPF (it was a combined experimental group)	Double-blind, parallel, randomized clinical trial	Placebo gel + sham PBM; CPP-ACPF paste + sham PBM; placebo gel + active PBM.	Soft-bristle toothbrush and non-desensitizing toothpaste provided; standardized oral-hygiene instructions	Continued standardized oral hygiene; no additional desensitizing agents	3	24 h between sessions	Dentin hypersensitivity to tactile and evaporative stimuli	Baseline; after 1st, 2nd, and 3rd sessions; 1-month follow-up ; VAS (0–10 cm)	None reported	CPP-ACPF + PBM produced the greatest DH reduction, especially for evaporative stimulus, and was the only group with significant HRQL (DHEQ) improvement at 1-month follow-up
Suri 2016	Diode laser (GaAlAs)	980 nm (975 ± 10 nm); 2 W; continuous wave; ~166 J/cm²; 320 μm fiber; non-contact; perpendicular orientation; 1 mm distance; each area irradiated twice for 20 s	Randomized parallel-group controlled clinical Trial	Placebo; 5% NaF varnish; 5% NaF varnish + diode laser.	Scaling and polishing 1 week before treatment; oral-hygiene standardization; soft-bristle toothbrush; non-desensitizing toothpaste; no desensitizing agents	Continued use of non-desensitizing toothpaste and soft brush; avoidance of other desensitizing agents during study	1 session (laser applied twice for 20 s each)	Single session; assessments at 24 h, 1 week, 1 month, 2 months	Dentin hypersensitivity (pain intensity) at baseline, 24 h, 1 week, 1 month, 2 months	Tactile stimulus and air-blast stimulus; Visual Analog Scale	None reported; no pulpal damage, allergic reactions, or loss of vitality	All three active groups (NaF varnish, diode laser, combination) showed significant reduction in DH. The combination (NaF + DL) was superior to laser alone or NaF alone.
Flecha 2013	Diode laser (GaAlAs, infrared)	795 nm wavelength; 120 mW power; spot size 0.031 cm²; energy density 2.88 J/cm²; 8 s per point; 3 cervical points per tooth	Controlled, randomized, double-masked, split-mouth, clinical trial.	Cyanoacrylate glue (active comparator)	No prior professional or OTC desensitizing treatment; participants instructed not to use desensitizing products	Continued avoidance of desensitizing products; no additional post-treatment restrictions reported	3	48 h	Dentin hypersensitivity pain	Numeric Rating Scale in response to air-jet and cold-sprayBaseline; 24 h; 30, 90, and 180 days	No adverse effects; one laser-treated tooth developed acute sensitivity and was excluded	Cyanoacrylate was non-inferior to low-intensity diode laser in reducing dentin hypersensitivity; no significant inter-group differences at 6 months
Tevatia, 2017	1. Diode laser, 980 nm2. Diode laser, 980 nm + 5% KNO₃	GaAlAs diode laser, 980 nm; 62.2 J/cm²; 0.5 W; non-contact pulse mode; 320 μm fiber; 60 s per site; 3 applications per session	Randomized clinical trial; four parallel groups	1. 5% KNO₃2. Placebo/commercial toothpaste	Scaling and root planing performed; oral hygiene instruction using modified Bass technique; standardized toothpaste without desensitizing agents provided	Standardized oral hygiene; brief post-KNO₃ restriction.	1	—	Dentinal hypersensitivity pain	Tactile test using dental explorer; air-blast test; cold-water test; VAS 0–10	No adverse effects reported, including allergy, ulceration, redness, or staining	Combined 5% KNO₃ and diode laser produced the greatest pain reduction, with approximately 97–99% relief at 6 weeks. Diode laser alone outperformed 5% KNO₃ alone. Combination therapy was recommended for dentinal hypersensitivity.
Doshi 2014	Diode laser (GaAlAs)	660 nm wavelength; continuous mode; 25 mW output; total energy 4.5 J; irradiance 11.36 mW/cm²; exposure time 3 min/session; irradiated area 2.2 cm²; sweeping motion; beam shape elliptical; beam profile multimode.	Randomized controlled double-blinded split-mouth study	Placebo laser	Phase I therapy including scaling and root planing; 0.2% chlorhexidine mouthrinse for 2 weeks; flap surgery performed after 4 weeks	Not reported	3	Once daily for 3 consecutive postoperative days	Dentinal hypersensitivity and postoperative pain	Air-blast assessed using VAS and VRS	No adverse effects or complications reported	Laser-treated sites showed statistically significant reduction in dentinal hypersensitivity and pain compared with placebo sites by day 7 post-surgery (p < 0.05)
Bal 2015	Diode laser	685 nm wavelength; 25 mW power; 9 Hz frequency; energy density 2.0 J/cm²; irradiation time 100 s; interrupted mode; 1 cm² area; optic fiber tip positioned 2 mm from tooth surface	Randomized, split-mouth, clinical trial.	Placebo (physiological saline applied to control tooth)	Oral hygiene education at baseline; provision of soft toothbrush and toothpaste without anti-hypersensitivity agents; participants instructed not to use mouthwash or fluoride products	Continued use of soft toothbrush and non-desensitizing toothpaste; avoidance of mouthwash and fluoride products throughout study	1	Not applicable (single session)	Dentin hypersensitivity response to evaporative (air-blast) stimulus	Visual Analogue Scale Pretreatment; immediately post-treatment; days 10, 30, 60, and 90 post-treatment	No side effects reported	Both laser and arginine-calcium carbonate paste significantly reduced DH; combined use did not improve efficacy beyond single treatments.
Lee 2015	Er, Cr: YSGG laser	Er, Cr: YSGG (Waterlase MD); wavelength 2.78 μm; three irradiation phases: 0.25 W, 20 pps, 16% water/16% air (phases 1–2), phase 3 without water; 30 s per phase	Randomized, single-blinded clinical trial with three parallel arms.	Strontium chloride (SC) dentifrice (10% SC + 10% CaCO₃); n-CAP dentifrice (20% nano-carbonate apatite)	Supra- and subgingival scaling; baseline tactile and air-blast sensitivity assessment; standardized toothbrush and brushing instructions	During maintenance period (weeks 2–4), all groups brushed with fluoride dentifrice without desensitizing ingredients	2	1-week interval between laser sessions	Dentin hypersensitivity (pain reduction)	Tactile sensitivity via VAS; evaporative air sensitivity via Schiff air-blast score Baseline; 1 week; 2 weeks (end of treatment); 4 weeks (end of maintenance)	No adverse events or laser-related side effects reported	Both Er, Cr: YSGG laser and n-CAP dentifrice were effective in reducing dentin hypersensitivity; laser showed superior initial desensitizing effect, while n-CAP demonstrated more sustained effect during maintenance
Maximiano, 2019	Nd: YAG laser	Nd: YAG laser; pulsed mode; 1 W power; 10 Hz repetition rate; 100 mJ per pulse; 85 J/cm² energy density; pulse width 150 µs; 400 μm quartz fiber optic; contact mode; fiber perpendicular to tooth surface; four irradiations per tooth — two mesio-distal and two occlusal-gingival; each irradiation up to 15 s with 10 s interval for thermal relaxation	Double-blind, randomized, placebo-controlled clinical trial Double-blind, randomized, placebo-controlled clinical trial	Placebo-controlled Nd: YAG laser group	Teeth free of plaque and calculus; scaling performed if needed; no analgesic use within 72 h; no desensitizing toothpaste use during previous 3 months; isolation with cotton rolls and saliva ejector before irradiation	Rinsing after CSP application; no additional post-treatment restrictions reported	1	—	Pain intensity / dentin hypersensitivity	Visual analog scale, after evaporative stimulus using air jet, tactile stimulus Assessed at baseline, 5 min, 1 week, and 4 weeks after treatment	No adverse effects reported; transient pain during Nd: YAG irradiation resolved immediately	All treatments — Nd: YAG laser, CSP paste, and placebo — significantly reduced dentin hypersensitivity compared with baseline, with no significant differences between groups at any time point.
Lier, 2002	Nd: YAG laser	Nd: YAG laser; 4 W power; 400 μm fiber tip; total application time 2 min: 30 s without cooling + 90 s with water cooling; applied on buccal surface in mesial–distal direction	Split-mouth, double-blind, placebo-controlled, randomized clinical trial	Placebo laser: laser beam switched off, coolant active	Supragingival plaque removal with pumice, no fluoride, before baseline assessment	Standardized toothbrush and toothpaste without anti-hypersensitivity agents, including fluoride; no mouthrinses or fluoride tablets for first 4 weeks	1	Single application	Dentin hypersensitivity; pain response to air stimulus	Visual Analogue Scale, VAS; air blast applied at cervical third of tooth; assessed at baseline, immediately post-treatment, 1 week, 4 weeks, and 16 weeks	No adverse reactions; all teeth remained vital; no pulp or surface pathology observed	Nd: YAG laser reduced pain similarly to placebo; no statistically significant differences between laser and placebo at any time point; improvements in both groups persisted up to 16 weeks
Orhan, 2010	Diode laser, GaAlAs, red wavelength	655 nm; 25 mW output; continuous mode; contact application; 160 s per tooth per session; energy density 4 J/cm² per tooth	Randomized controlled clinical trial; single-blind	Distilled water placebo; sham laser	Removal of supragingival plaque with pumice; isolation with cotton rolls; baseline evaporative stimulus testing; standardized toothbrush and non-desensitizing toothpaste during study	No brushing for 12 h post-treatment; no chewing for 3 h; no mouthrinse or fluoride products during trial	6 sessions, laser group	No interval; 6 consecutive days	Pain intensity; dentin hypersensitivity	Evaporative stimulus + Visual Analog Scale, VAS 0–100; assessed at baseline, 24 h after treatment, and 7 days after treatment	No adverse effects; no pulp irritation; no soft-tissue irritation; all teeth remained vital	Low-level diode laser therapy produced a significant reduction in dentin hypersensitivity at 24 h and 7 days, comparable to glutaraldehyde-containing desensitizer, and significantly superior to placebo groups. The placebo groups, distilled water and placebo laser, showed no significant improvement in hypersensitivity scores at any time point.
Jain, 2020	Diode laser, GaAlAs	Wavelength: 810 nm; power: 0.5 W; mode: continuous emission; application: non-contact, beam perpendicular to buccal surface; exposure time: 2 min per tooth; device: diode laser, AMD Lasers, USA	Split-mouth randomized clinical trial	Active comparators within split-mouth design: 5% NaF varnish alone; diode laser alone; NaF varnish + diode laser; no placebo laser arm	Full-mouth scaling and root planing; oral hygiene instructions; baseline DH assessment; exclusion of patients with desensitizing or periodontal treatment in previous 6 months	Patients instructed not to eat for 1 h after each session and to resume toothbrushing after 12 h	1 session per modality	Not applicable; single application	Dentin hypersensitivity	Visual Analog Scale; stimuli: air-blast, cold, tactile; assessed at baseline, 1 week, 2 weeks, 1 month, 3 months, and 6 months	Not reported	All groups showed significant DH reduction over time, P < 0.05; diode laser alone and diode + NaF produced significantly greater and more sustained DH reduction than NaF varnish alone; no significant difference between laser alone and combination therapy over 6 months
Gentile, 2004	Diode laser, 670 nm	670 nm; constant power 15 mW; 4 J/cm²; area 4 mm²; punctual application at 3 points — distal, central, mesial; perpendicular to surface; 2 min per tooth	Randomized controlled trial; parallel-group design	Placebo laser	Prophylaxis with rubber cup or wet cotton ball; drying with cotton rolls; no analgesics 6 h before treatment	—	6	48–72 h	—	—	No complications	There was a statistically significant reduction in painful sensation after each laser application and between the beginning and end of treatment, p < 0.0001. However, there was no statistically significant difference between the laser-treated group and placebo-control group at the end of treatment or at the intermediate evaluation after 6 weeks, p > 0.05.
Garcia, 2017	Diode laser, 660 nm	660 nm; 200 mW; CW; illuminated area 1.15 cm²; 173 mW/cm²; 60 s; 12 J; 10.4 J/cm²; applied at 5 mm distance with oscillating movements	Randomized split-mouth clinical trial	Placebo laser	Patients treated with scaling and root planing prior to laser therapy; baseline examination	—	1	—	Dentinal hypersensitivity discomfort/pain	Visual Analog Scale; tactile stimulus using sharp probe; thermal stimulus using air jet	No adverse effects or complications reported; all teeth remained vital	There was a significant difference, p < 0.01, in discomfort to thermal and mechanical stimulation between control and diode laser sites at all evaluation periods. Discomfort decreased immediately following diode laser therapy and continued to decrease throughout the study duration. PBM can reduce dentinal hypersensitivity without detrimental pulpal effects.
Yahya 2022	Diode laser (660–900 nm)	Diode laser (660–900 nm), continuous mode, 90 mW, 60 s per tooth (cervical and incisal areas), distance 1 mm, no cooling	Split-mouth, parallel group	5% NaF varnish only (Group 1) vs. Laser only (Group 2) vs. Combination (Group 3)	Good oral hygiene; no active caries, enamel defects, or periodontal disease; Professional in-office bleaching with 40% hydrogen peroxide	Participants instructed to avoid food/drink for 2 h after NaF varnish; no specific instructions for laser alone	1 session	-	Before bleaching, immediately after bleaching, immediately after desensitizing treatment	Cold test and Visual Analogue Scale	Not reported	All desensitizing methods (NaF, LLLT, combination) significantly reduced post-bleaching sensitivity with no significant difference among them
Pantuzzo 2020	Diode laser (GaAlAs)	808 nm wavelength; infrared GaAlAs semiconductor diode laser; applied at a central point on exposed root surface for 60 s; single-point application	Randomized Single-Blinded Clinical Trial	Placebo (gel with acrylic resin block)	Not reported	Not reported	1	–	Pain reduction due to dentin hypersensitivity	Evaporative stimulus and tactile stimulus pain assessed using VAS and VRSVAS: immediately, 6 h, 12 h, 24 h after treatment; VRS: immediately, 15 min, and 7 days after treatment	No complications reported	Diode laser therapy was more effective in reducing dentin hypersensitivity than fluoride or placebo; significant reduction observed for evaporative stimulus (P = 0.002); fluoride showed no significant effect
Yilmaz a 2011	GaAlAs diode laser (810 nm)Er, Cr: YSGG laser (2780 nm)	GaAlAs diode laser: 810 nm, continuous mode, 8.5 J/cm², 60 sEr, Cr: YSGG laser: 2780 nm, hard tissue mode, non-contact, 0.25 W, 20 Hz, pulse duration 140 ms, 0% water, 10% air, 30 s, scanning cervical area	Randomized, controlled, double-blind, split-mouth clinical trial	No treatment	4-week oral hygiene program; professional tooth cleaning; instruction on oral hygiene; baseline DH assessment	Soft toothbrush and toothpaste without anti-hypersensitivity agents; no mouthrinse or fluoride products	1 session	Follow-up at immediately, 1 week, 1 month, and 3 months	Dentine hypersensitivity	Evaporative air stimulus and Visual Analogue Scale	No adverse effects or complications reported	Both Er, Cr: YSGG and GaAlAs diode lasers significantly reduced dentine hypersensitivity immediately after treatment, with effects maintained up to 3 months; no significant difference between laser groups
Naghsh 2020	Diode laser	660-nm diode laser: 30 mW power, continuous mode, contact and perpendicular to tooth surface, sweeping (forward–backward) motion, irradiation time 120 s per tooth.810-nm diode laser: 100 mW power, continuous mode, contact and perpendicular to tooth surface, sweeping motion, irradiation time 120 s per tooth	Randomized, double-blind, split-mouth, controlled clinical trial	Index radiation only; no active laser irradiation	Teeth free of plaque and calculus; scaling performed if needed; no analgesic use within 72 h; no desensitizing toothpaste use during previous 3 months; isolation with cotton rolls and saliva ejector before irradiation	No specific post-treatment restrictions reported	4	Weekly (1-week interval)	—	—	No adverse effects reported	Both 660-nm and 810-nm diode lasers significantly reduced dentin hypersensitivity compared with control; the 810-nm diode laser showed a more sustained and long-lasting pain-reduction effect than the 660-nm laser
Yilmaz 2011 b	Er, Cr: YSGG laser (2780 nm)	Er, Cr: YSGG laser (Waterlase MD), 2780 nm, hard tissue mode, non-contact, 0.25 W, repetition rate 20 Hz, 0% water, 10% air, 30 s per surface, scanning cervical area	Controlled, randomized, split-mouth clinical trial	Placebo (same laser device without emission)	4-week pre-treatment period with professional prophylaxis; oral hygiene instructions; baseline DH and plaque index assessment	Soft toothbrush and toothpaste without anti-hypersensitivity agents; no mouthrinse or fluoride	1 session	Follow-up at immediately, 1 week, 1 month, and 3 months	Dentine hypersensitivity	Evaporative air stimulus and Visual Analogue Scale	No adverse effects or complications reported	Er, Cr: YSGG laser significantly reduced dentine hypersensitivity compared with placebo immediately after treatment, and the effect was maintained for up to 3 months
Yilmaz 2011 c	Diode laser (GaAlAs, 810 nm)	810 nm GaAlAs diode laser, continuous mode, 500 mW, 60 s, 8.5 J/cm², non-contact (2 mm), scanning cervical area	Randomized, double-blind, split-mouth controlled clinical trial	1. Placebo laser2. NaF varnish3. Placebo NaF (saline)	Periodontal maintenance for a year; oral hygiene program prior to treatment	Soft toothbrush and toothpaste without desensitizing agents; no mouthwash or fluoride	1	Single application	Change in dentine hypersensitivity pain scores	Evaporative air stimulus; VAS recorded immediately, 1 week, 1, 3, and 6 months	No adverse effects; no pulpal or allergic complications reported	GaAlAs diode laser and NaF varnish significantly reduced DH compared to placebo; laser showed more stable long-term effect than NaF
Alencar, 2020	Diode laser, photobiomodulation	Photobiomodulation with diode laser; parameters not reported in abstract	Randomized, double-blind, placebo-controlled clinical trial	Placebo PBM, simulated laser + nHAP-free toothpaste	Baseline assessment of DH; inclusion of subjects with hypersensitive teeth	Not reported	2	Not reported	Change in dentin hypersensitivity intensity	VAS after tactile and evaporative stimuli; assessed at baseline, after 1st and 2nd treatment sessions, and at 1 month	No adverse effects reported	nHAP and PBM were effective in reducing DH; combined therapy did not provide additional benefit over individual treatments
Lizarelli, 2007	Two active groups: (1) Diode laser, 660 nm, LILT; (2) LED system, 630 ± 5 nm, LEDT	LILT laser: 660 nm diode laser; 25 mW, 0.025 W; continuous mode; spot size 4.0 mm²; 10 s per spot; energy density 6.0 J/cm², 5.4 J/cm² delivered after PVC attenuation; 4 irradiation points per tooth, 3 cervical and 1 apical; contact mode	Single-blind, randomized clinical trial	Placebo, sham illumination with device off	Prophylaxis with pumice powder and 3% hydrogen peroxide prior to each sensitivity test and treatment session	Daily flossing, correct brushing, and daily use of alcohol-free mouth rinse	3 treatment sessions; results demonstrated that 2 sessions were sufficient	72 h between treatment sessions; follow-up evaluations at 15 and 30 days post-treatment	Dentin hypersensitivity; assessed immediately after each treatment session, sessions 1, 2, and 3, and during follow-up at 15 and 30 days after the final session	Evaporative air blast applied to the cervical region; pain response recorded as improvement +, worsening −, or no change =	No side effects or damage to dental structure reported; tooth vitality preserved throughout the study	LILT, laser, and LEDT were equally effective in treating dentin hypersensitivity. A third treatment session was not necessary; two sessions were sufficient

Discussion

In this review, we aimed to synthesize the clinical efficacy of various laser modalities in treating DH, also evaluating the impact of specific clinical application protocols. The included studies were categorized into three primary groups based on the laser employed: Nd: YAG, Er, Cr: YSGG, and Diode lasers.

The included studies were classified into three categories based on the type of laser used: Nd: YAG, Er, Cr: YSGG, and diode lasers (Table 2)

Nd: YAG lasers

Two studies [14, 15] investigated the efficacy of Nd: YAG lasers compared to placebo controls. Although both studies reported a significant reduction in VAS scores among DH patients, no statistically significant difference was observed between the laser and placebo groups across all follow-up periods. Given that both studies used 400 μm fiber optics, Maximiano [14] achieved comparable clinical outcomes using a lower power setting (1 W) compared to Lier [15] (4 W). This suggests that lower power densities may be sufficient to elicit therapeutic effects, potentially minimizing the risk of pulpal thermal damage.

Er, Cr: YSGG lasers

Four studies [16–19] demonstrated that Er, Cr: YSGG lasers significantly reduced VAS scores compared to placebo controls. The characteristics of the laser device used in these studies were similar, utilizing the MZ6 tip (600 mm diameter, 6 mm length) at a power of 0.25 W. Yillmaz et al. [18], further indicated that increasing the power to 0.5 W resulted in superior reduction of VAS scores and enhanced dentinal tubule occlusion compared to 0.25 W; however, this effect was only observed immediately post-irradiation, with no long-term follow-up provided. After one laser treatment session, similar effects were observed for three months with diode laser [16], and more sustained effects of Er, Cr: YSGG laser were shown for three months compared to placebo [17]. Nevertheless, long-term data from Lee [19], suggested that n-CAP toothpaste may outperform laser therapy in the long-term management of DH-related symptoms.

Diode lasers

The majority of the included studies (n = 19) investigated the efficacy of diode lasers in managing DH. Given the significant variability in laser parameters, these studies were categorized into three distinct wavelength ranges:

1. 630–700 nm: Nine studies [20–28] in this group utilized low-power diode lasers (< 1 W). Despite the methodological similarities among these studies, Naghsh et al. [26], who conducted a comprehensive follow-up across short, medium, and long-term intervals, reported no significant difference in therapeutic efficacy between the 660 nm and 810 nm laser groups.1.

2. 700-850 nm: Nine studies [16, 26, 29-35]. ] in this group also employed low-power configurations (< 1 W). While methodologies were largely consistent, Guanipa Ortiz et al. [32] noted that the laser therapy group did not significantly outperform the control group during certain follow-up periods. Additionally, the study by Pentozza et al. [33] lacked long-term follow-up data. Conversely, Yilmaz et al. [16, 34] demonstrated the superiority of laser therapy during a 6-month follow-up period [16, 34].

3. 850-980 nm: Two studies [36, 37] were identified in this range. Although their methodologies were similar, Suri et al. [37] utilized a high-power setting (2 W). Tevatia et al. [36] reported enhanced therapeutic effects at a 6-week follow-up, achieving clinical outcomes comparable to other studies despite utilizing a lower energy density.

Combination of laser and chemical agent

Seven studies [20, 22, 32, 35–38] evaluated the combined application of lasers and chemical agents against monotherapy groups. Four studies [20, 22, 35, 38] indicated that while the combination therapy was not significantly more effective than laser therapy alone, it frequently outperformed chemical agents used as monotherapy. In contrast, other researchers [32, 36, 37] reported that combined modalities yielded superior clinical outcomes compared to both laser and chemical monotherapies. With the exception of Suri et al. [37], all studies utilized low-power diode lasers with wavelengths ranging from 660 to 890 nm (Yahya et al. [38] utilized a dual-wavelength approach of 660 and 900 nm). The chemical agents employed included nHAP, CPP-ACP, NaF, KNO3, and arginine-calcium carbonate paste. Notably, Tevatia et al. [36] demonstrated the clear superiority of combined therapy across all follow-up intervals.

Influence of laser parameters on clinical outcomes

Beyond the laser type, specific laser parameters, particularly power output, play a critical role in clinical success (Table 2).

Low-power and high-power lasers

High-power Nd: YAG lasers (1 W and 4 W) significantly improved DH symptoms, although no statistically significant difference was observed compared to placebo groups. Regarding Er, Cr: YSGG lasers, power settings ranged from 0.25 to 0.5 W, with Yilmaz et al. [18] finding that 0.5 W was significantly more effective than 0.25 W. Most diode laser studies utilized low-power settings (0.015–0.5 W), except for one instance [37]. Current evidence suggests that within the therapeutic range of low-power diode lasers, increasing the output power does not inherently correlate with improved clinical outcomes. This phenomenon can be explained by the principle that photobiomodulation (PBM) is primarily dependent on energy density (J/cm2) and the total energy delivered to the tissue, rather than instantaneous power [39, 40]. Consequently, if the same energy density is achieved by modulating irradiation time, different power levels can yield similar analgesic results. This is because the predominant mechanism of low-power lasers involves the modulation of nerve conduction and the reduction of excitability in A-delta fibers [39]. While several studies have confirmed significant DH reduction even at low power levels [16, 34], some literature suggests that higher power settings in diode lasers may be beneficial. This approach aims to increase energy deposition on the dentinal surface to facilitate partial tubule occlusion through controlled protein denaturation and mild thermal effects [41], representing a mechanistic departure from classical photobiomodulation.

Radiation mode

The laser modalities employed in the included studies varied in their radiation modes. Er, Cr: YSGG and Nd: YAG lasers were utilized in pulsed mode, whereas most diode laser studies employed continuous wave (CW) radiation, with the notable exception of Bal et al. [20], who utilized a chopped-mode pulsed diode laser. Theoretically, pulsed mode can facilitate heat dissipation by reducing the duty cycle, thereby allowing for sufficient thermal relaxation times between pulses to prevent heat accumulation in hard tissues and the pulp. However, within the low-power parameters typically used for DH treatment, most studies have reported no significant clinical or safety differences between pulsed and CW modes [39, 42]. This is probably because, at these low power levels, pulpal temperature remains well within physiological safety limits regardless of the mode. Furthermore, the predominant therapeutic mechanism in these cases is photobiomodulation and the modulation of nerve conduction, rather than the induction of thermal effects required for protein denaturation [39, 41]. Consequently, when total energy delivered and energy density are similar, the radiation mode may not exert a different influence on clinical outcomes.

Contact vs. non-contact application

All Er, Cr: YSGG and Nd: YAG applications were performed in a non-contact manner. For diode lasers, the majority of studies utilized non-contact techniques, whereas three studies [25–27], employed contact application. which used lasers in a contact manner, all other studies were non-contact. The distances from the tooth surface varied from 2 mm to 3 cm. It is noteworthy that non-contact irradiation generally contributes to a reduction in surface temperature, potentially enhancing the safety profile of the procedure [25–27]. Reported.

Radiation angle

In most reviewed studies, laser irradiation was directed perpendicular to the target area. While perpendicular irradiation typically maximizes light penetration into the dentin, thereby potentially enhancing therapeutic efficacy [41, 42], the choice of angle involves a critical trade-off. Some literature suggests that an irradiation angle of approximately 45° may be preferable to mitigate the risk of pulpal thermal damage. This angled approach promotes surface scattering and reflection, preventing excessive energy accumulation deep within the dentinal tubules [39, 42]. Therefore, the selection of an irradiation angle must represent a clinical balance between maximizing therapeutic penetration and ensuring pulpal safety, tailored to the specific laser parameters and clinical objectives.

Irradiation site and pattern

The spatial distribution of laser energy varied significantly across the studies. Most protocols focused on the cervical region, employing either a scanning/sweeping pattern with overlapping coverage or targeting specific points (mesial, distal, and middle) near the marginal gingiva [21], or central point on exposed root surface [33]. Other studies implemented more extensive coverage, such as homogeneous irradiation of the middle third of the crown [32], the incisal area [38], or a mesio-distal and occluso-cervical pattern [14]. Beyond the crown, irradiation sites frequently included the root apex [22, 30, 31] and the mid-root area [20].

Irradiation duration

The duration of laser exposure was highly variable, reflecting the diversity of clinical protocols. Point-specific irradiation times ranged from 8 to 60 s, while regional or scanning protocols required longer exposure times, ranging from 30 to 180 s.

In addition to these optical parameters, the protocols for tooth preparation before, during, and after laser therapy are critical factors that warrant careful clinical consideration (Table 2)

Pre- operative management

Optimal pre-operative preparation involves maintaining oral hygiene through the use of a soft toothbrush employing the modified Bass technique, interdental flossing, and 0.2% chlorhexidine mouthwash for two weeks prior to laser therapy [21]. Evidence suggests that the primary pre-laser protocol across most studies involves scaling and root planing; this procedure facilitates more effective laser irradiation by removing dental calculus and plaque.

Intra-operative management

During laser therapy, procedural protocols necessitate drying the tooth surface with sterile gauze and ensuring effective moisture control through isolation with cotton rolls and high-volume suction.

Post-procedure management

Critical post-treatment instructions include the avoidance of oral intake (ranging from 30 min [31], and 1 h [34, 35] to 3 h [27]), and the cessation of toothbrushing for durations between 1 h [34] and 12 h [27, 35]. Following these intervals, most studies recommend resuming routine oral hygiene using a soft toothbrush and fluoride toothpaste; in certain instances, daily use of an alcohol-free mouth rinse has been advised [25].

Treatment frequency and intervals

Twelve studies utilized a single-session laser irradiation protocol. Suri [37] and Tevatia [36] administered three and two irradiations per session, respectively. Other protocols involved two or four weekly sessions [19, 26, 30], while three-session regimens were administered either consecutively [21] or at intervals of 24 [32], 48 [29], or 72 h [25, 31]. Additionally, one study implemented six sessions at 24- and 48-hour intervals [24]. Notably, Maximiano incorporated a 10-second interval between the irradiation of different points on a tooth to facilitate thermal relaxation [14]. Data indicate that increasing the number of treatment sessions does not inherently guarantee prolonged or more stable therapeutic outcomes; several studies demonstrated that a single session with various laser types remained effective during multi-month follow-ups. However, given that multi-session protocols (e.g., with 48 to 96-hour intervals) are common in clinical studies and have yielded significant results in treating dentinal hypersensitivity (DH), a protocol consisting of three sessions administered every other day may represent a rational and safe clinical approach. Such intervals allow for dental tissue thermal relaxation while potentially enhancing anti-allergic effects, consistent with randomized controlled trials (RCTs) that reported significant pain reduction following multiple sessions at 2-to-4-day intervals [43, 44].

Measurment of dentin hypersensitivity (Table 2)

The majority of studies employed evaporative stimuli (air jet at 40 psi, 1 mm distance, for 3 s, with adjacent teeth isolated) and tactile stimuli (exploratory probe application over cervical dentin) to evaluate sensitivity via the Visual Analogue Scale (VAS). A significant challenge in evaluating laser efficacy for DH is the methodology of measurement. DH-induced pain is an inherently subjective, inter-individual symptom. Consequently, objective assessment remains problematic; although various scales, such as VAS and Verbal Rating Scales (VRS), are currently utilized, a “gold standard” for pain assessment in DH has yet to be established [45].

Conclusions and clinical recommendations

Nd: YAG, Er, Cr: YSGG, and Diode lasers demonstrate efficacy in the treatment of dentinal hypersensitivity, although in certain instances, their effects are comparable to placebo. Various wavelengths of low-power diode lasers are effective for DH management. Furthermore, the combination of diode lasers with chemical agents may yield superior efficacy compared to monotherapy in specific cases. Clinical selection of the appropriate laser modality is based on the specific clinical condition, equipment availability, cost-effectiveness, and ease of operation and maintenance.

Author contributions

“S.SH. and M.R. and S.S. Made substantial contributions to conceptualization and design and N.SH. and S.SH. and M.R. and S.S. Data/evidence collection, and investigation and N.SH. and M.R. and SH.V. Formal analysis and interpretation of data and N.SH. and M.R. and S.S and SH.V. Involved in writing – original draft and N.SH. and S.S. and SH.V. Involved in writing – review & editing. All authors reviewed the manuscript.”

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

Not applicable.

Informed consent

Not applicable.

Competing interests

The authors declare no competing interests.

Clinical trial number

Not applicable.