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.

Pulpal anesthesia of maxillary first molars using 4% articaine infiltration in patients with symptomatic irreversible pulpitis: a randomized controlled clinical trial.

OBJECTIVES: This study aimed to compare the anesthetic efficacy of 1.8 mL (one cartridge) and 3.6 mL (two cartridges) buccal infiltration and buccal plus palatal infiltration of 4% articaine in maxillary first molar teeth with symptomatic irreversible pulpitis. MATERIALS AND METHODS: This randomized single-blind clinical trial was conducted on 45 patients with symptomatic irreversible pulpitis of maxillary first molars (Trial Registration No: IRCT2015011020238N2_2015). The patients were randomly divided into three groups (n = 15) for buccal infiltration of 1.8 mL articaine plus 1:100,000 epinephrine (group 1), buccal infiltration of 3.6 mL articaine (group 2), and buccal infiltration of 1.8 mL articaine plus palatal infiltration of 0.5 mL articaine (group 3). The pain intensity was measured by the Heft-Parker visual analog scale (VAS) during injection and during access cavity preparation. No pain or mild pain during treatment was considered as successful anesthesia. Data were analyzed by the Tukey's post hoc test. RESULTS: The three groups had a significant difference in frequency of the perceived pain during injection (P = 0.01). A higher volume of 4% articaine and injection of articaine in both buccal and palatal sides provided a significantly higher anesthesia success rate (P = 0.049 and P < 0.01, respectively). The highest success rate was recorded in group 3 (93.33%) followed by group 2 (80%) and then group 1 (53.33%). CONCLUSIONS: Increasing the administered volume of 4% articaine with 1:100,000 epinephrine and addition of palatal infiltration to buccal infiltration of articaine can significantly increase the success of anesthesia in maxillary first molars with symptomatic irreversible pulpitis. CLINICAL RELEVANCE: Achieving deep anesthesia in teeth with irreversible pulpitis is a critical parameter in management of patients who are in urgent need of root canal treatments.

The Evaluation of SWEEPS Plus Antimicrobial Photodynamic Therapy with Indocyanine Green in Eliminating Enterococcus faecalis Biofilm from Infected Root Canals: An In Vitro Study.

OBJECTIVES: This study aimed to assess the efficacy of shockwave-enhanced emission photoacoustic streaming (SWEEPS) plus antimicrobial photodynamic therapy (aPDT) using indocyanine green (ICG) for the elimination of Enterococcus faecalis biofilm from infected root canals. MATERIALS AND METHODS: thirty sound human single-canal teeth were chosen and standardized to have 12 mm of root length. The root canals were shaped and prepared by means of ProTaper rotary files. After sterilization of the teeth, the canals were inoculated with E. faecalis for 2 weeks. The teeth were then randomly divided into six groups (n = five) of control, ICG, ICG + 808 nm diode laser, ICG + SWEEPS, ICG + 808 nm diode laser + SWEEPS, and 5.25% sodium hypochlorite (NaOCl). Following treatment, the number of colony-forming units (CFUs)/mL were calculated for each group. Statistical analysis was carried out using one-way ANOVA. For multiple comparisons, Tukey's test was used as the post hoc test. RESULTS: NaOCl alone showed the highest efficacy (p < 0.001). The ICG + 808 nm diode laser + SWEEPS group displayed significantly lower amounts of bacteria than either the ICG + 808 nm diode laser or SWEEPS (p < 0.001). There was a statistically significant difference detected between the ICG + 808 nm diode laser and ICG + SWEEPS (p = 0.035). CONCLUSIONS: SWEEPS can effectively increase the photosensitizer distribution in the root canal space, and its application along with irrigants can bring about promising results.

Residual antibacterial effects of a mixture of silver nanoparticles/calcium hydroxide and other root canal medicaments against Enterococcus faecalis.

Background/purpose: Intracanal medicaments with high residual inhibition effects are used to achieve successful endodontic treatment and prevent reinfection. This in vitro study aimed to assess antimicrobial residual effects of different intracanal medicaments against Enterococcus faecalis (E. faecalis) in root dentin one week after drug therapy. Materials and methods: Seventy human teeth were standardized to have 15 mm of length and were prepared by ProTaper rotary system. The teeth were randomly divided into six experimental (n = 10) and two control (n = 5) groups and subjected to drug therapy as follows; group CHX: 2% chlorhexidine gel, group CH: calcium hydroxide paste, group CH/CHX: mixture of calcium hydroxide and 2% CHX, group TAP: triple antibiotic paste, group DAP: double antibiotic paste, group CH/AgNPs: mixture of CH paste and silver nanoparticle suspension. After one week, the medicaments were removed from the root canals and E. faecalis was inoculated into the canals. The teeth were incubated at 37 °C for 24 h. Using a size 40 hedstrom file, dentin chips were collected and number of colony forming units were counted. Results: The difference between all experimental groups was statistically significant in this regard (P < 0.05) except for DAP and TAP groups, in which, no bacterial colony was noted after culture. After DAP and TAP, the lowest colony count was noted in CH/AgNPs, CH/CHX and CHX groups. The highest colony count was noted in CH group. Conclusion: Our results showed favorable residual antibacterial effects of TAP, DAP and CH/AgNP medicaments after one week of application.

Comparative effects of Er:YAG laser, and EDTA, MTAD, and QMix irrigants on adhesion of stem cells from the apical papilla to dentin: A scanning electron microscopic study.

Background: Dentin conditioning can affect the adhesion of stem cells in endodontic regenerative treatments. This study aimed to assess the effects of the most commonly used endodontic irrigants, namely, ethylenediaminetetraacetic acid (EDTA), MTAD, and QMix in comparison with Er:YAG laser (as a novel modality for root canal disinfection) on the adhesion of stem cells from the apical papilla (SCAPs) to dentin. Material and Methods: Forty dentin specimens were prepared and subjected to different treatments in 5 groups (n=8) of control, irrigation with EDTA for 1 minute, irrigation with MTAD for 5 minutes, irrigation with QMix for 5 minutes, and Er:YAG laser irradiation. SCAPs were isolated from third molar tooth buds that two-thirds of their roots had formed. The cells were cultured on dentin specimens for 3 days and were counted using scanning electron microscopy (SEM). Results: MTAD resulted in significantly lower adhesion of cells to dentin compared with other groups (P<0.05). All other modalities induced cell adhesion with no significant difference with each other (P>0.05). Conclusions: Despite many favorable properties, MTAD cannot serve as an optimal irrigant in endodontic regenerative procedures since it inhibits the adhesion of SCAPs to dentin and impairs an important step in tissue engineering. Key words:Endodontic Regeneration, Er-YAG laser, MTAD, QMix, EDTA, SCAP, stem cell adhesion.

Canal transportation and centering ability of twisted file and reciproc: a cone-beam computed tomography assessment.

INTRODUCTION: The purpose of this in vitro study was to compare the canal transportation and centering ability of Twisted File (TF) to that of Reciproc system. METHODS AND MATERIALS: Forty noncalcified roots with mature apices, minimum length of 19 mm and an apical curvature of 15-30 degrees (according to Schneider's method), from freshly extracted mandibular and maxillary teeth, were selected for this study. Samples were randomly divided into two groups (n=20) and canal preparation with either TF or Reciproc was performed according to manufacturers' instruction. Pre- and post-instrumentation cone-beam computed tomography (CBCT) images were captured and the extent of canal transportation and centering ability of the files were calculated, using the NNT Viewer software and Photoshop CS5, at levels of 3, 4, and 5 mm from the apex. The Mann-Whitney U test was used to analyze the statistical significance between the two groups. RESULTS: One fracture occurred in the TF group. TF produced more transportation than Reciproc in both mesiodistal and buccolingual directions; however, the difference between the two systems were not statistically significant except for the TF group at 5-mm distance from the working length, where the difference was significant (P>0.05). CONCLUSION: Both file systems were able keep the original curvature of the canal and thus can be considered safe for clinical application.

Interfacial fracture toughness of different resin cements bonded to a lithium disilicate glass ceramic.

OBJECTIVES: To evaluate the effect of HF acid etching and silane treatment on the interfacial fracture toughness of a self-adhesive and two conventional resin-based cements bonded to a lithium disilicate glass ceramic. METHODS: Lithium disilicate glass ceramic discs were prepared with two different surface preparations consisting of gritblasted with aluminium oxide, and gritblasted and etched with hydrofluoric acid. Ceramic surfaces with a chevron shaped circular hole were treated by an optimized silane treatment followed by an unfilled resin and then three different resin cements (Variolink II, Panavia F2, and Multilink Sprint). Specimens were kept in distilled water at 37°C for 24h and then subjected to thermocycling. The interfacial fracture toughness was measured and mode of failures was also examined. Data were analysed using analysis of variance followed by T-test analysis. RESULTS: No statistically significant difference in the mean fracture toughness values between the gritblasted and gritblasted and etched surfaces for Variolink II resin cement was found (P>0.05). For the gritblasted ceramic surfaces, no significant difference in the mean fracture toughness values between Panavia F2 and Variolink II was observed (P>0.05). For the gritblasted and etched ceramic surfaces, a significantly higher fracture toughness for Panavia F2 than the other cements was found (P<0.05). CONCLUSIONS: The interfacial fracture toughness for the lithium disilicate glass ceramic system was affected by the surface treatment and the type of luting agent. Dual-cured resin cements demonstrated a better bonding efficacy to the lithium disilicate glass ceramic compared to the self-adhesive resin cement. CLINICAL SIGNIFICANCE: The lithium disilicate glass ceramic surfaces should be gritblasted and etched to get the best bond when used with Panavia F2 and Multilink Sprint resin cements, whereas for the Variolink II only gritblasting is required. The best bond overall is achieved with Panavia F2.