Evaluation of the effectiveness of the photobiomodulation in the treatment of dentin hypersensitivity after basic therapy. A randomized clinical trial

Effect of photobiomodulation on dentin hypersensitivity: a randomized controlled double-blind clinical trial

OBJECTIVES

To investigate if photobiomodulation (PBM) can reduce dentin hypersensitivity (DH) through a randomized, controlled, double-blind clinical trial.

MATERIALS AND METHODS

One hundred and twelve patients experiencing DH after non-surgical scaling and root planing (SRP) were enrolled and divided into the Experimental Group - SRP + PBM (660 nm, 1.061 J/cm²) and the Control Group - SRP + PBM simulation. The primary outcome was the assessment of DH through tactile and thermal stimulation using the visual analog scale (VAS) after seven days. Additionally, paracetamol was prescribed and quantified as needed. Also, the impact of oral health on participants' quality of life using the Oral Health Impact Profile (OHIP-14) questionnaire was applied. Outcome assessments occurred seven days and one-month post-application.

RESULTS

In both 7 and 30 days, pain values were significantly lower in the experimental group compared to the control group (P = 0.001 and < 0.001, respectively). No differences were observed between the groups regarding analgesic usage. The experimental group also showed a significant improvement in the impact of oral health on participants' quality of life (P < 0.001), with lower OHIP-14 scores at all time points (P = 0.008).

CONCLUSIONS

These results suggest that photobiomodulation significantly reduces pain at 7- and 30-days following scaling and root planing. Additionally, it is associated with improvements in the oral health-related quality of life in patients with dentin hypersensitivity.

CLINICAL TRIAL REGISTRATION

NCT05946265.

Effect of Low- and High-Level Laser Therapy on the Treatment of Dentin Hypersensitivity: An Umbrella Review

Introduction: Dentin hypersensitivity (DH) is a prevalent unpleasant condition which might affect quality of life. Laser therapy is one of the non-invasive treatments for dentin hypersensitivity. The aim of this umbrella review was to assess the effect of lasers on the treatment of dentin hypersensitivity by analyzing the previously published systematic reviews and meta-analyses. Methods: Electronic databases (PubMed, Embase, Scopus, Cochrane, and ISI) were searched to identify relevant systematic reviews and meta-analyses based on the keyword search strategy. Two independent reviewers carried out the selection of studies, extraction of data, and assessment of methodological quality. The actual overlap of primary studies was measured through the visual tool known as the citation matrix and three indices of % overlaps, covered area (CA), and corrected covered area (CCA). The reviews were appraised for methodological quality through A Measurement Tool to Assess Systematic Reviews (AMSTAR)-2, and the risk of bias was evaluated using the Risk of Bias in Systematic Reviews (ROBIS) tool. Results: Following eliminating duplicates, a total of 2,768 articles were found, and of them, 9 systematic reviews met the inclusion criteria. Six of them included a meta-analysis as well. The actual overlap of primary studies was low. The AMSTAR 2 tool classified one systematic review as high quality, three as moderate quality, three as low quality, and the remaining two as critically low quality. The results of the included reviews generally showed that all types of lasers reduced dentin hypersensitivity compared to placebo/no treatment. Conclusion: Lasers are effective in treating dentin hypersensitivity.

The use of laser photobiomodulation as pre-anesthetic tissue management technique in reducing injection pain in children

BACKGROUND

One of the main goals for pediatric dentists is to offer a painless anesthesia experience. Laser photobiomodulation is among the suggested strategies to decrease injection pain. So, this study aimed to assess the impact of laser photobiomodulation on local anesthesia (LA) injection pain in children and its effect on the efficacy of LA during pulpotomy and SSC procedures.

METHODS

The research was carried out as a randomized controlled clinical trial with two parallel group design. It involved 64 cooperative healthy children, age range from 5 to 7 years, each having at least one maxillary molar indicated for pulpotomy. Children were randomly allocated to one of the two groups based on the pre-anesthetic tissue management technique used: test group received laser photobiomodulation, while control group received topical anesthetic gel. Pain during injection, pulpotomy, and SSC procedures was assessed using physiological measures (Heart Rate (HR)), subjective evaluation (modified Face-Pain-Scale (FPS), and objective analysis (Sound-Eye-Motor scale (SEM)).

RESULTS

A total of 64 children with mean age 6.23 ± 0.78 participated in this research. The mean HR scores were significantly lower in the laser PBM group during buccal and palatal infiltration injections. The SEM mean scores were significantly lower in the laser PBM group during both injections. For the FPS scale, the number of children who recorded satisfaction during injection was significantly higher in laser PBM group. There was no statistically significant difference in mean HR as well as in SEM and FPS scores between the two groups during pulpotomy and SSC procedures. Comparisons between the two study groups were performed using independent samples t- and Mann-Whitney U tests. Significance was set at p value < 0.05.

CONCLUSION

Laser photobiomodulation is a promising non-pharmacological pre-anesthetic tissue management technique in children that offered less painful injection compared to topical anesthetic gel without compromising the effectiveness of LA.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05861154. Registered on 16/5/2023.

Single-session associative protocol for dentin hypersensitivity management: a 1-year randomized, blinded clinical study

Objectives

This study aimed to establish a single-session associative protocol for non-restorative management of dentin hypersensitivity (DH).

Materials and Methods

Twenty-four individuals with DH and a minimum sensitivity level of 4 on the visual analog scale (VAS) were selected. The study was conducted in a split-mouth design, with each participant (n = 20) having at least 1 affected tooth in all quadrants. The management protocols consisted of control group: universal adhesive, Neural Desensitizing Protocol group: 5% potassium nitrate, Mixed Desensitizing Protocol (PAM) group: 5% sodium fluoride and 5% potassium nitrate, Remineralizing Desensitizing Protocol (PDR) group: surface-partially reacted glass technology photopolymerizable varnish. Evaluations were performed immediately after application, at 1 week, 1 month, 2 months, and 12 months using the VAS sensitivity test.

Results

The scores were subjected to statistical analysis using the Friedman test (p < 0.05), Durbin-Conover test (p < 0.05), and Wilcoxon test (p < 0.05). At the 12-month evaluation, all groups showed statistically significant differences compared to the initial assessment. For the evaluation after 12 months, there was a statistically significant difference between the PAM group, the control group, and the PDR group.

Conclusions

It can be concluded that all groups were effective in controlling DH, but there were significant results in the control group and PDR group. The clinical relevance of this study is to demonstrate that the application of single-session desensitizing protocols can be effective in controlling DH for up to 12 months.

Trial Registration

Brazilian Clinical Trials Registry Identifier: RBR-4r63d7s.

Influence of diode laser treatment and casein phosphopeptide-amorphous calcium phosphate paste on eroded root dentin

Introduction

It is still unclear whether the pretreatment for dentin hypersensitivity can interfere with the adhesive-dentin bonding strength. This study aimed to evaluate in vitro the effect of pretreatment with a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste and diode laser on the shear bond strength of the etch-and-rinse adhesive system in the adhesive-dentin interface.

Materials and Methods

Seventy-five bovine root specimens were randomly divided into five experimental groups (n = 15). Samples were eroded by six cycles of immersion in hydrochloric acid solution (0.01M; pH = 1.2) for 20 s each, at 45 min intervals, and treated with: G2 - no treatment, G3 - CPP-ACP, G4 - diode laser (970 nm), and G5 - CPP-ACP + Diode laser. After treatments, the morphology of the specimens was analyzed.

Results

The fracture mode of each group was evaluated after restoration with composite resins in the treated area. Data were analyzed by the one-way ANOVA and Tukey's test (P < 0.05). G3 showed the highest values for shear bond strength; there was no significant difference among G1, G3, and G5 (P > 0.05). The adhesive fracture was predominant for all groups.

Conclusion

The use of desensitizers containing CPP-ACP, associated or not with a diode laser, increased the bond strength of the etch-and-rinse adhesive system on eroded root dentin.

Dentinal tubule blockage using nanobioglass in the presence of diode (980 nm) and Nd:YAG lasers: an in vitro study

OBJECTIVES

The main objective of this study was to enhance the blockage of dentinal tubules using nanobioglass in the presence of diode (980 nm) and Nd:YAG lasers in order to reduce permeability and dentin hypersensitivity.

MATERIALS AND METHODS

Thirty-six dentinal samples were randomly divided into 6 subgroups (n = 6): (A) control, (B) diode laser (980 nm, 3-W), (C) Nd:YAG laser (1064, 1.0-W), (D) nanobioglass, (E) nanobioglass + diode laser (980 nm), (F) nanobioglass + Nd:YAG laser. The average number of open dentinal tubules was qualitatively and quantitatively evaluated by scanning electron microscopy (SEM). Data were evaluated by SPSS software version 22, Kruskal-Wallis test, and Mann-Whitney tests with Bonferoni's correction (α = 0.008).

RESULTS

Based on the results of Mann-Whitney test, there was a significant difference in the mean number of open dentinal tubules between the control group and the other groups (p < 0.008). However, the difference among the other groups was not statistically significant (p > 0.008).

CONCLUSIONS

Findings of this study showed that high-power laser radiation, such as Nd:YAG and diode (980 nm) alone or with nanobioglass, has a significant effect on the blockage of dentinal tubules.

CLINICAL RELEVANCE

Introduction of non-invasive methods with long-term and lasting effect on reducing pain and discomfort caused by dentin hypersensitivity.

Involvement of substance P, osteopontin and satellite glial cells on photobiomodulation-induced antinociceptive effect in an experimental model of dentin hypersensitivity

The aim of this work was to investigate the involvement of substance P (SP), osteopontin (OPN), and satellite glial cells (SGC) on photobiomodulation-induced (PBM) antinociceptive effect in an experimental model of dentin hypersensitivity (DH). Rats ingested isotonic drink (ID, pH 2.87) for 45 consecutive days and after this period received PBM irradiation at λ660 nm or λ808 nm (1 J, 3.5 J/cm², 100 mW, 10 s, 0.028 cm², continuous wave, 3 consecutive daily sessions), and were evaluated for nociceptive behavior 24, 48, 72 h, and 14 days after laser treatments. ID ingestion induced an increase on thermal sensitivity of DH characteristics in rats that was completely reversed by PBM treatment at both 660 and 808 nm. Immunohistochemical analysis revealed increased SP expression at both dentin-pulp complex (DPC) and trigeminal ganglia (TG) of DH-rats which did not occur in PBM groups by PBM treatment. Also, the increase of glial fibrillary acidic protein (GFAP) observed in the TG of DH-rats was also reversed by PBM treatment. Finally, PBM at both 660 and 808 nm increased OPN expression in the dentin-pulp complex of DH-rats after 14 days of PBM treatment. All in all, this data demonstrates that PBM reverses nociception in a DH experimental model by inhibiting neurogenic inflammation and inducing a regenerative response.

Low-power laser and potassium oxalate gel in the treatment of cervical dentin hypersensitivity-a randomized clinical trial

OBJECTIVE

To evaluate the effectiveness of different protocols for the treatment of cervical dentin hypersensitivity (CDH) in non-carious cervical lesions (NCCLs).

MATERIALS AND METHODS

The CONSORT checklist was used to design this study. The sample with n = 74 participants (389 NCCLs) was randomly allocated into three groups: G1, potassium oxalate (Oxa-Gel BF); G2, GaAlAs (gallium-aluminum-arsenate) low-power laser (100 mW, 808nn, 60 J/cm²); and G3, potassium oxalate (Oxa-Gel BF) associated with the GaAlAs low-power laser. The CDH was triggered by the evaporative stimulus test (EST) and by the tactile stimulus test (TST). The visual analog scale (VAS) was used to quantify the degree of CDH. Changes in sensitivity were assessed from baseline over 3 weeks. Data were analyzed for NCCLs using mixed-effects models with unstructured direct product covariance structure (α = 0.05).

RESULTS

After the first application, participants from G1 and G3 had a reduction in CDH (p < 0.05) compared with group G2 for TST. After the second application, G3 participants had a reduction in CDH (p < 0.05) in relation to G2 for both stimuli. Reduction in CDH (p < 0.05) occurred over 3 weeks for EST and TST for all groups; however, there was no difference between groups at the end of the therapies.

CONCLUSION

Potassium oxalate was more effective in reducing immediate CDH. After four applications, all groups showed similar results for the reduction of CDH.

CLINICAL RELEVANCE

GaAlAS laser irradiation and oxalate potassium gel could reduce the symptoms of CDH; thus, they are viable alternatives for the treatment of this condition. Chemical occlusion of dental tubules showed effective results after a shorter time interval.

TRIAL REGISTRATION

Brazilian Clinical Trials Registration Platform under protocol number RBR-4ybjmt. http://www.braziliantrials.com/?keywords=RBR-4ybjmt&order=%7Eensaios.patrocinador_primario.

Examination of the Effect of the Combined Use of Nd: YAG Laser Irradiation and Mechanical Force Loading on Bone Metabolism Using Cultured Human Osteoblasts

Introduction: In recent years, laser irradiation in the near-infrared ray (NIR) area has been reported to promote bone healing. There are also reports that laser irradiation accelerates orthodontic tooth movement. In this study, we investigated the effect of NIR laser irradiation and mechanical stimulation on osteoblasts. Methods: We seeded osteoblast-like cells and laser irradiation was performed 24 hours after cell seeding. In addition, a control group not receiving anything, a group receiving only Nd: YAG (neodymium-doped yttrium aluminum garnet) laser irradiation, a group receiving only centrifugal loading, and a group receiving both Nd: YAG laser irradiation and centrifugal force loading were set, and after 24 hours and after 48 hours, cells were collected and quantitative real-time polymerase chain reaction (PCR) was performed. Results: 24 hours after laser irradiation, the gene expression of alkaline phosphatase (ALP), the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) was significantly higher in the 2.0 W group than in the control group. In addition, the RANKL/OPG ratio was higher in the 2.0 W group than in the control group. Also, in the group using laser irradiation and centrifugal loading in combination, 24 hours after laser irradiation, ALP and OPG showed significantly higher values than those in the centrifugal load only group. Furthermore, the RANKL/OPG ratio also showed high values. Conclusion: These results suggest that osteoblast-like cells activate genes related to bone metabolism by combining mechanical stimulation and laser irradiation. This helps to elucidate the influence of laser irradiation during tooth movement.

Effect of photobiomodulation with low-level laser therapy combined with potassium nitrate on controlling post-bleaching tooth sensitivity: clinical, randomized, controlled, double-blind, and split-mouth study

OBJECTIVES

To evaluate the effect of photobiomodulation with low-level laser therapy (PBM-LLLT) combined with 5% potassium nitrate (KNO₃) on controlling tooth sensitivity (TS) after in-office tooth bleaching.

MATERIALS AND METHODS

Fifty volunteers were selected based on the inclusion and exclusion criteria and were randomly allocated into four groups: G1 (control): placebo gel application, 35% hydrogen peroxide bleaching (HP35) and mock PBM-LLLT without light emission; G2: placebo gel application, bleaching with HP35 and PBM-LLLT; G3: application of KNO₃, bleaching with HP35 and mock PBM-LLLT; and G4: application of KNO₃, bleaching with HP35 and PBM-LLLT. A pain assessment questionnaire was used to evaluate TS during the 21 days of treatment. The Friedman test was used for intragroup analysis, and the Wilcoxon and Mann-Whitney tests were used for intergroup comparisons.

RESULTS

The intragroup evaluation showed significant differences among the evaluation times in all groups (p ≤ 0.05). The highest pain sensitivity levels were recorded on the 1st, 8th, and 15th days. In G1, TS manifested for up to 3 days after each bleaching session, while G2, G3, and G4 presented TS only on the days of the bleaching sessions. Intergroup analysis showed that TS manifestation differed significantly between G1 and the other groups (p ≤ 0.05) but did not differ significantly among G2, G3, and G4 (p ≥ 0.05).

CONCLUSION

PBM-LLLT and KNO₃ are effective at reducing pain sensitivity after tooth bleaching, but no synergistic effect between these treatments was observed for the different evaluation periods.

CLINICAL RELEVANCE

The effect of PBM-LLLT combined with KNO₃ on post-bleaching tooth sensitivity is similar to their individual use alone.

Effects of Nd:YAG low-level laser irradiation on cultured human osteoblasts migration and ATP production: in vitro study

Low-level laser therapy has become one of the fastest growing fields of medicine in recent years. Many in vivo and in vitro studies have shown that laser irradiation activates a range of cellular processes in a variety of cell types and can promote tissue repair. However, few in vitro experiments have evaluated the effects of laser irradiation on cells in real time. The purpose of this study was to examine the effects of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser irradiation on the migration of cultured human osteoblasts. A dedicated 96-well plate was used, and confluent cultures of the human osteoblast-like cell line, Saos-2, were injured with a wound maker. The wounded cells were then exposed to the Nd:YAG laser (wavelength of 1064 nm) for 60 s at 0.3 W (10 pps, 30 mJ). The total energy density was about 10.34 J/cm². Images of the wounds were automatically acquired inside the CO₂ incubator by the IncuCyte ZOOM™ software. In addition, after laser irradiation, the production of adenosine triphosphate (ATP) was measured using the CellTiter-Glo™ Luminescent Cell Viability Assay. Migration of cells from the border of the original scratch zone was accelerated by laser irradiation. In addition, compared with the control group, significant enhancement of ATP production was observed in the irradiated group. The present study showed that Nd:YAG laser irradiation (wavelength of 1064 nm, 0.3 W, 10 pps, 30 mJ, 10.34 J/cm², irradiation time 60 s) may contribute to the regeneration of bone tissues owing to enhanced osteoblast cell migration.