The use of lasers for direct pulp capping

The application of lasers in vital pulp therapy: clinical and radiographic outcomes

The main purpose of vital pulp therapy (VPT) is to preserve the integrity and function of the pulp. A wide variety of materials and techniques have been proposed to improve treatment outcomes, and among them, the utilization of lasers has gained significant attention. The application of lasers in different stages of VPT has witnessed remarkable growth in recent years, surpassing previous approaches.This study aimed to review the applications of lasers in different steps of VPT and evaluate associated clinical and radiographic outcomes. An electronic search using Scopus, MEDLINE, Web of Science and Google Scholar databases from 2000 to 2023 was carried out by two independent researchers. The focus was on human studies that examined the clinical and/or radiographic effects of different laser types in VPT. A total of 4243 studies were included in this narrative review article. Based on the compiled data, it can be concluded that although current literature suggests laser may be proposed as an adjunct modality for some procedural steps in VPT, more research with standardized methodologies and criteria is needed to obtain more reliable and conclusive results.

The application of lasers in vital pulp therapy: a review of histological effects

Vital pulp therapy (VPT) is primarily intended to preserve the vitality of pulp tissues, which have been exposed for any reason. Various materials and techniques have been proposed to improve treatment outcomes, including the use of lasers. This study aimed to review the histological results of different dental lasers including low-level lasers, carbon dioxide (CO2), erbium-doped yttrium aluminum garnet laser (Er:YAG), neodymium-doped yttrium aluminum garnet (Nd:YAG), erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers, and diode lasers for VPT. This focused review included a comprehensive electronic search of Scopus, MEDLINE, Web of Science, and Google Scholar databases from 2000 to 2022 by two independent investigators. Different combinations of keywords were used, and reference mining of related papers was done. The review included studies related to histologic evaluation of laser-assisted vital pulp therapy that stated the laser parameters that were used. Articles with radiographic or clinical assessments or articles lacking necessary data were excluded. Non-English articles were excluded unless their abstract was in English and encompassed the necessary data. Most studies indicated the efficacy of lasers for reduction of inflammation, acceleration of healing, and increasing the thickness of dentinal bridge. According to the evidence, lasers used in combination with pulp capping agents are beneficial to enhance the success rate of VPT.

Biomodulator of Diode Laser Irradiation on Odontoblast-Like Cells by Expression of Vascular Endothelial Growth Factor-A and Transforming Growth Factor-β1

OBJECTIVE

 This study aimed to prove that the effect of diode laser 650-nm irradiation to the expression of vascular endothelial growth factor (VEGF)-A and transforming growth factor (TGF)-β1 plays important roles in dental pulp-regulating cell proliferation, differentiation, and revascularization.

MATERIALS AND METHODS

 The research was performed by randomized posttest only control group design using Rattus norvegicus. A total of 48 samples were provided and divided into eight groups of 6 samples each with a random-sample allocation. Each group were prepared, and perforation of maxillary first molar were done. In control groups (groups 1-4), glass ionomer cement (GIC) was used to restore the teeth, while in laser groups (groups 5-8), the teeth were irradiated with diode laser 650 nm for 40 seconds before application of GIC. Half of the groups (groups 1, 2, 5, and 6) were necropsied in 7 days, and the rest (groups 3, 4, 7, and 8) were necropsied in 14 days. Immunohistochemistry (IHC) evaluation were implemented to check the expression of both VEGF-A and TGF-β1.

STATISTICAL ANALYSIS

 Both data of VEGF-A and TGF-β1 expression were analyzed using a one-way ANOVA (α = 0.05) with SPSS statistical software.

RESULTS

 The study showed that the diode laser 650-nm irradiation increased expression of VEGF-A and TGF-β1, and there was a significant difference between diode laser and control group on VEGF-A expression (p = 0.001) and TGF- β1 (p = 0.000) on days 7 and 14.

CONCLUSION

 Diode laser 650 nm with 40-second irradiation time shows increment from day 7 to day 14 reflecting increase in pulp healing by modulating VEGF-A and TGF-β1 expression since days 7 to 14.

Pulpal and periapical tissue response after direct pulp capping with endosequence root repair material and low-level laser application

Background

The study aims to investigate the pulp and periapical reaction and healing after capping with EndoSequence Root Repair Material (ERRM) combined with low-level laser application.

Methods

In 6 rabbits, pulps were exposed via class V, half of the samples received a low-level diode laser at 980 nm. Thereafter, cavities were capped with regular-set ERRM. The specimens were processed for histomorphological examination after 2 weeks and two months.

Results

After 2 weeks, images show mild inflammation and organized odontoblasts in lased group. The non-lased group shows more severe inflammation. The predentin thickness was thicker in the lased group with statistical significance (p < 0.05). After 2 months, inflammatory cells were sparse in both lased and non-lased groups. In the periapical area, group one showed dilated blood vessels and thick fibrous connective tissues. In group two, there were more numerous maturations of PDL fibers with scattered inflammatory cells and congested blood vessel.

Conclusions

Using low-level laser therapy in combination with ERRM for pulp capping shortens the inflammatory phase and enhances healing.

The effect of low-level laser on the quality of dentin barrier after capping with bioceramic material: A histomorphometric analysis

The study aims to investigate the quality of dentin barriers and pulp reaction to EndoSequence Root Repair Material (ERRM) combined with low-level laser application. In eight dogs, pulps were exposed via class V, half of the samples received low-level diode laser at 870 nm. Thereafter, cavities were capped with fast-set or regular-set ERRM. The specimens were processed for histomorphological and immunohistochemical examination after 2 weeks and 2 months. Dentin bridges were observed in all samples, and 87.5% were complete. The low-level laser group had significantly more reparative dentin area than the non-lased group (p < 0.05). The dentin bridges were found to have an unprecedented tubularity of 43%-89%. Tiny dentin island formation was observed within the material particles. Initial mild-to-moderate inflammatory reactions were observed, which subsided after 2 months. RUNX2 and osteocalcin staining were evident for all samples at both time intervals. Low-level laser combined with bioactive ERRM is effective in inducing reparative dentin formation.

Efficacy of Er:YAG laser-assisted direct pulp capping in permanent teeth with cariously exposed pulp: A pilot study

Direct pulp capping is a minimally invasive method to preserve pulp integrity. We evaluated the treatment efficacy of Er:YAG laser irradiation combined with direct pulp capping for pulp exposure due to caries. A total of 21 patients with 22 teeth were enrolled in the conventional group (calcium hydroxide), and 24 patients with 25 teeth were enrolled in the laser-assisted group (Er:YAG laser irradiation at settings of 10 Hz, 50 mJ; combined with calcium hydroxide). The cumulative success rate of the conventional group and the laser-assisted group was 68.2% and 91.7% at 12 months, respectively. Results showed that the laser-assisted procedure increased the survival time (β = 0.04, OR = 0.07), while proximal-occlusal cavities in molars decreased the survival time (β = 0.03, OR = 12.5). Er:YAG lasers improve the effectiveness of conventional direct pulp capping (using Dycal) with limited side-effects and can be applied clinically.

Clinical and Histological Study on Direct Pulp Capping With CO2 Laser Irradiation in Human Teeth

The study aimed to histologically evaluate wound healing of exposed human pulp on direct pulp capping using super-pulsed CO₂ laser preirradiation. In this single-blind clinical trial, 28 third molar teeth of 17 volunteers were randomly capped with either CO₂ laser irradiation (n=14) or Dycal (calcium hydroxide cement; n=14) and restored using resin composite. The laser was operated in super-pulsed mode (pulse duration, 0.2 ms; interval, 5.8 ms; 0.003 J/pulse). The irradiation conditions were a power output of 0.5 W, an irradiation time of 15 seconds, repeat mode (10-ms irradiation and 10-ms intervals, for a total beam exposure time of 7.5 seconds), total applied energy of 3.75 J, and an activated air-cooling system. Each tooth was extracted at six or 12 months posttreatment and prepared for histological evaluation. We evaluated the parameters of pulp tissue disorganization, inflammatory cell infiltration, reparative dentin formation (RDF), and bacterial penetration. There were no significant differences between groups for all parameters at each postoperative period (Mann-Whitney U-test, p>0.05). CO₂ laser irradiation completely controlled bleeding and exudate from the exposed pulp. The CO₂ laser group had a tendency to delay RDF compared with the Dycal group, but 4 of 7 teeth from the CO₂ laser group showed a complete dentin bridge at 12 months posttreatment.

Histopathological findings of an exposed human pulp carbonised by CO2 laser irradiation: A case report

This report shows the healing process of an exposed pulp carbonised by CO₂ laser irradiation prior to the application of a capping material. Six intact teeth from four volunteers were irradiated by CO₂ laser and randomly capped with either an adhesive resin (SE bond) (n = 3) or calcium hydroxide-based cement (Dycal) (n = 3). The laser was operated in super-pulsed mode (power output, 0.5 W) for an irradiation time of 30 s. All cavities were restored with composite resin. Each tooth was extracted at approximately 30, 50 or 260 days post treatment and prepared for histological evaluation. CO₂ laser irradiation controlled exudate and bleeding from each exposed pulp. Histological images revealed Dycal promoted complete dentine bridge formation at the carbonised pulp surface, and laser energy affected not only the pulp surface but also the deeper part of the pulp chamber.

[Vital pulp therapy of damaged dental pulp]

The development of an expert consensus on vital pulp therapy can provide practical guidance for the improvement of pulp damage care in China. Dental pulp disease is a major type of illness that adversely affects human oral health. Pulp capping and pulpotomy are currently the main methods for vital pulp therapy. Along with the development of minimal invasion cosmetic dentistry, using different treatment technologies and materials reasonably, preserving healthy tooth tissue, and extending tooth save time have become urgent problems that call for immediate solution in dental clinics. This paper summarizes the experiences and knowledge of endodontic experts. We develop a clinical path of vital pulp therapy for clinical work by utilizing the nature, approach, and degree of pulp damage as references, defense and self-repairing ability of pulp as guidance, and modern technologies of diagnosis and treatment as means.