Effect of photobiomodulation therapy on TGF-ß release from dentin, migration and viability of dental pulp stem cells in regenerative endodontics treatment: An ex vivo study.

BACKGROUND AND AIM: Regenerative endodontic procedures (REPs) are oriented by the principles of tissue engineering, incorporating dental pulp stem cells (DPSC), crucial growth factors like Transforming growth factor-ß (TGF-ß1), and scaffolds to facilitate the regeneration of dental pulp tissues. The present study aimed to investigate the effect of photobiomodulation (PBM) therapy, using an 808 nm diode laser on cellular modulation mechanisms in REPs. METHOD AND MATERIAL: A total of 108 human dentin discs obtained from intact single root teeth were randomly assigned into six groups (n = 8): 1. Positive control (EDTA), 2. PBM-1 (3 J/cm2), 3. PBM-2 (5 J/cm2), 4. EDTA+PBM-1, 5. EDTA+PBM-2, and 6. Negative control (NaOCl). Then, an extract solution was prepared from each disc and the concentration of released TGF-ß1 from the discs was measured using enzyme-linked immunosorbent assay (ELISA). Moreover, the extract solution was added to DPSC culture medium to evaluate cell viability and migration through MTT assay and scratch test, respectively. RESULT: The group exposed to PBM-1 showed the highest cell viability, while treatment with EDTA and EDTA+PBM-2 decreased cellular viability. Also, the PBM-treated groups showed significantly higher release of TGF-ß1 compared to the negative control. EDTA and EDTA+PBM-1 showed the highest release among all the groups. No significant difference was found between EDTA and EDTA+PBM-1, as well as between PBM-1 and PBM-2. Moreover, the PBM-1 group exhibited the highest migration after 24 h, which was significantly greater than other groups, except for the PBM-2 group. CONCLUSION: According to the obtained data, 808 nm mediated-PBM (3 J/cm2), both independently and in conjunction with EDTA, enhanced the release of TGF-ß1 from dentin and improved cell viability and migration of DPSCs. It seems that, PBM under the specific parameters employed in this study, could be an effective adjunctive therapy in REPs.

Effect of Fluorohydroxyapatite on Biological and Physical Properties of MTA Angelus.

Objectives: This study aimed to assess the effect of addition of fluorohydroxyapatite (FHI) on biological and physical properties of mineral trioxide aggregate (MTA) Angelus. Materials and Methods: In this in vitro, experimental study, nano-FHI powder was first synthesized, and the morphology and chemical structure of particles were evaluated by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Three groups were evaluated in this study: MTA Angelus, MTA modified with 10% FHA, and MTA modified with 15% FHA. After mixing, the materials were applied to ring molds (10 mm diameter, 1 mm height), and the setting time of the three groups was evaluated according to ISO6876 and ASTMC266-03 with a Gillmore needle. The pH was measured using a pH meter at 24 and 48 hours and 7 days after mixing. The cytotoxicity of the materials was assessed in freshly mixed form and after 1 and 7 days using the methyl thiazolyl tetrazolium (MTT) assay according to ISO10993-5. Data were analyzed by one-way and repeated measures ANOVA and Tukey's test (alpha = 0.05). Results: The addition of FHA to MTA significantly decreased the initial setting time (P < 0.05) and had no significant effect on cell viability (compared with pure MTA Angelus) at 1 and 7 days. However, modified MTA groups in freshly mixed form showed significantly lower cell viability (P < 0.05). The pH remained alkaline at all time points. Conclusion: Addition of 15% FHA to MTA Angelus decreased its setting time with no adverse effect on cell viability (except for fresh form) or pH.

Evaluation of the Effect of Common Analgesics on Pulpal Sensibility Tests: A Clinical Trial.

INTRODUCTION: Accurate diagnosis is one of the most important steps before endodontic treatment. The aim of this study was to assess the effect of 2 commonly used analgesics namely ibuprofen and acetaminophen on the cold and electric pulp test (EPT) results in participants with symptomatic irreversible pulpitis (SIP). METHODS: This clinical trial evaluated 41 participants with pain due to SIP. The cold test and EPT were performed for teeth with SIP, and also for the corresponding tooth with healthy pulp in the contralateral quadrant. The participants then received 500 mg acetaminophen, 400 mg ibuprofen, or the placebo in the 3 groups. The cold test and EPT were repeated at 20, 40, and 60 minutes after medication intake, and the results were compared with the pretreatment values. RESULTS: In the acetaminophen group, the results of cold test significantly decreased 40 (P < .05), and 60 (P < .05) minutes after analgesic intake in teeth with SIP and after 40 minutes (P < .05) in the corresponding contralateral teeth with healthy pulp. In the ibuprofen group, the cold test results significantly decreased at 20 (P < .05), 40 (P < .05), and 60 (P < .05) minutes after analgesic intake in teeth with SIP and after 40 minutes (P < .05) in the corresponding contralateral teeth with healthy pulp. The EPT results were not significantly affected by the studied analgesics at any time point (P > .05). There was no significant difference among the study groups regarding sex (P > .05). CONCLUSION: It appears that both acetaminophen and ibuprofen can affect the pulpal response to the cold sensibility test. However, the studied medications had no significant effect on the EPT results. Therefore, dental clinicians should be aware of the possible effects of such medications on the cold test response.

Evaluation of the effect of the photobiomodulation therapy on the pain related to dental injections: A preliminary clinical trial.

BACKGROUND: Pain from dental injections is a common reason why people fear dentistry and avoid dental treatment. Thus, researchers have attempted to find methods to decrease dental injection pain. OBJECTIVES: Considering the analgesic effect of the photobiomodulation therapy (PBMT), the aim of this study was to evaluate the effects of PBMT on the pain caused by dental anesthetic injections. MATERIAL AND METHODS: This randomized, split-mouth, triple-blind clinical trial evaluated 60 bilateral canine teeth in 30 dental students. After the random selection of the test (laser) quadrant, the injection site was irradiated with a 940 nm diode laser. Buccal infiltration anesthesia was then administered by injecting lidocaine plus epinephrine with a short needle. The level of pain experienced during the injection was determined using a 100-millimeter visual analog scale (VAS). The same procedure was performed for the control (no laser) quadrant, with the difference being that the laser handpiece was turned on, but no radiation was administered. The 2 groups were compared using the non-parametric Wilcoxon signed-rank test. RESULTS: The mean VAS pain scores were 21.2 ±15.7 for the laser quadrant and 27.9 ±18.9 for the control quadrant; this difference was statistically significant (p = 0.030), but did not seem to be clinically relevant. CONCLUSIONS: The photobiomodulation therapy prior to dental anesthetic injections has no clinical advantage for reducing injection pain.

Evaluation of the relationship between buccolingual width of mesiobuccal root and root canal morphology of maxillary first molars by cone-beam computed tomography.

Background: One of the main reasons for the failure of root canal treatment is the incomplete knowledge of the root canal system. With respect to the complexity of maxillary molars root canal system, and the possibility of the relationship between the buccolingual width of the mesiobuccal root and root canal morphology in maxillary molars, the aim of this study is to determine this relationship with cone-beam computed tomography (CBCT). Materials and Methods: This in vitro study carried out on 311 CBCT scans. Maxillary first molars (n = 311) were evaluated in three sagittal, axial, and coronal planes. For each tooth the number of canals, presence of second mesiobuccal (MB2), buccolingual width of mesiobuccal root at the cementoenamel junction (CEJ), and mid-root level, and type of canals according to the Vertucci's classification were determined. Results: The results showed that 49.1% of first maxillary molars had 3 and 50.8% had four root canals. The most common canal type in the mesiobuccal root was Vertucci's Type I followed by Types II, IV, and V. The prevalence of MB2 in the Iranian subpopulation was 50.1%. In maxillary first molars with MB2, the buccolingual width of mesiobuccal root at the CEJ and mid-root level (P < 0.001) was significantly greater than the corresponding values in other one without MB2. Conclusion: The results showed that the buccolingual width of mesiobuccal root in maxillary first molars at the CEJ level and mid-root was correlated with the number of root canals.

Comparison of the effect of QMix and conventional root canal irrigants on push-out bond strength of fiber post to root dentin.

OBJECTIVES: This study aimed to assess the effect of application of QMix and common root canal irrigating solutions on the bond strength of fiber post to root dentin. MATERIAL AND METHODS: In this in-vitro study, 60 extracted incisor teeth were decoronated such that 15 mm of root length remained. The canals were prepared with ProTaper rotary system to F5 and filled with gutta-percha and AH26 sealer. Prior to post placement, the teeth were divided into four groups based on the type of final irrigating solution namely saline, 5.25% NaOCl, 2% chlorhexidine, and QMix. The fiber posts were then cemented with Panavia F2 resin cement. The roots were sectioned perpendicular to their longitudinal axis, and four sections with 1 mm thickness were made at the middle and coronal thirds of the roots. The push-out bond strength of fiber posts was measured by a universal testing machine in megapascals. Data were analyzed by two-way ANOVA and Tukey's test. RESULTS: The maximum and minimum bond strength values were noted in QMix and NaOCl groups in both the middle and coronal third of the root, respectively. But, there was no significant difference between the push-out bond strength in the middle or coronal third of the root (p = 0.054). Adhesive failure was the most common mode of failure in all groups. CONCLUSION: Use of QMix for post space irrigation does not compromise the bond strength of fiber post to root dentin, and can be used for final rinsing of the post space.

Evaluation of the Antimicrobial Effect of Mineral Trioxide Aggregate Mixed with Fluorohydroxyapatite against E. faecalis In Vitro.

Enterococcus faecalis is the dominant microorganism in chronic apical periodontitis. It is more resistant to local antiseptic agents than other endodontic microorganisms. Currently, mineral trioxide aggregate (MTA) is considered as an ideal material in many endodontic procedures. Some studies have shown that MTA has good antibacterial activity against E. faecalis. However, some studies have investigated the effect of incorporating some materials into MTA on its antibacterial activity against E. faecalis. No study has evaluated the effect of incorporating fluorohydroxyapatite nanoparticles (nano-FHA) on the antimicrobial activity of MTA. Therefore, the present study evaluated the antimicrobial effect of MTA mixed with nano-FHA on E. faecalis in vitro. The study was carried out on 18 samples in three groups: pure MTA, MTA mixed with 10 wt% of nano-FHA, and MTA mixed with 15 wt% of nan-FHA. The effect of nano-FHA on the antibacterial activity of MTA on E. faecalis was evaluated by evaluating the growth inhibition zone around each sample. The antimicrobial effect of samples on inhibiting E. faecalis biofilm formation and inhibiting microbial growth of E. faecalis in the planktonic phase was evaluated by disk agar diffusion (DAD), biofilm inhibition assay (BIA), and direct contact assay (DCA) tests, respectively. All the above tests were analyzed after 24 and 72 hours. Factorial designs were used for statistical analyses. Tukey tests were used for two-by-two comparisons. All the statistical analyses were carried out with SPSS 26. DAD results showed no formation of the growth inhibition zone in all the samples after 24 and 72 hours. The microbial colony counts in the BIA and DCA tests in the groups modified with FHA nanoparticles were significantly lower than the pure MTA group (P < 0.05). The microbial colony counts increased in all the groups over time (P < 0.05). Incorporating nano-FHA into MTA improved the antimicrobial activity of MTA against E. faecalis compared to pure MTA. The highest antimicrobial activity was achieved after incorporating 15 wt% of nano-FHA into MTA at the 72-hour interval.

Effect of different activations of silver nanoparticle irrigants on the elimination of Enterococcus faecalis.

OBJECTIVES: This study aimed to compare the efficacy of silver nanoparticles (AgNPs) irrigating solution alone and following activation with photon-induced photoacoustic streaming (PIPS), photodynamic therapy (PDT) with indocyanine green (ICG), passive ultrasonic irrigation (PUI), and manual dynamic activation (MDA) method for elimination of Enterococcus faecalis (E. faecalis) from the root canal system. MATERIALS AND METHODS: A total of 59 extracted human single-rooted teeth were collected and prepared. E. faecalis was inoculated into the root canals and incubated for 4 weeks. The teeth were then randomly divided into five experimental groups (n = 10): the AN group, irrigation with AgNPs alone; the AN/ICG/DL group, irrigation with AgNPs and ICG, then activation with diode laser; the AN/PIPS group, irrigation with AgNPs and activation with 0.3 W Er: YAG laser; the AN/MDA group, irrigation with AgNPs and activation with tapered gutta-percha; and the AN/PUI group, irrigation with AgNPs and activation with ultrasonic. Also, two control groups of irrigation with 2.5% sodium hypochlorite (n = 5) and no intervention (n = 4) were also used. Samples were collected from the dentinal chips before and after the intervention, and the percentage of reduction in colony count was calculated. RESULTS: A significant reduction in E. faecalis colony count was noted in all groups (P < 0.05). Maximum reduction in colony count was noted in AN/PIPS and AN/PUI groups by 91.03 and 91.29%, respectively. Minimum reduction was noted in the AN group alone. CONCLUSION: Activation with PUI and PIPS enhanced the efficacy of AgNPs irrigating solution for elimination of E. faecalis from the root canal system. CLINICAL RELEVANCE: AgNPs activated by ultrasound or PIPS can be used as an adjunct for disinfection of the root canal system in endodontic treatment.

Evaluation of Secondary Thermal Hyperalgesia Resulting from Pulpal Inflammation in Patients with Symptomatic Irreversible Pulpitis.

INTRODUCTION: Inflammation can lead to hyperalgesia and allodynia by activation or sensitization of peripheral and central nervous system neurons. This study aimed to assess the occurrence of secondary thermal hyperalgesia in patients with symptomatic irreversible pulpitis (SIP). METHODS: The cold sensitivity test (visual analog scale) was performed for the tooth with SIP, its adjacent sound tooth, the same sound tooth in the opposite jaw, and the contralateral sound tooth in the opposite quadrant of the same jaw. Next, the tooth with SIP underwent root canal treatment, and 3 weeks later, after complete elimination of pain, the teeth underwent cold sensitivity testing again. RESULTS: A total of 64 patients, including 41 women and 23 men 18-65 years old, were evaluated in this study. The response to the cold sensitivity test significantly decreased in the tooth with SIP (P < .001), its adjacent sound tooth (P < .001), and the same sound tooth in the opposite jaw (P = .004) but not in the contralateral sound tooth in the opposite quadrant of the same jaw (P = .45) after endodontic treatment. No significant difference was noted between men and women in the groups (P > .05). CONCLUSIONS: Hypersensitivity to cold test due to pulpal inflammation can also result in exaggerated response of the adjacent sound tooth and the same tooth in the opposite jaw to cold sensitivity test; these observations can be explained by the central and peripheral sensitization mechanisms.

Discoloration of teeth due to different intracanal medicaments.

OBJECTIVES: The objective of this study was to assess coronal discoloration induced by the following intracanal medicaments: calcium hydroxide (CH), a mixture of CH paste and chlorhexidine gel (CH/CHX), and triple antibiotic paste (3Mix). MATERIALS AND METHODS: Seventy extracted single-canal teeth were selected. Access cavities were prepared and each canal was instrumented with a rotary ProTaper system. The specimens were randomly assigned to CH, CH/CHX, and 3Mix paste experimental groups (n = 20 each) or a control group (n = 10). Each experimental group was randomly divided into 2 subgroups (A and B). In subgroup A, medicaments were only applied to the root canals, while in subgroup B, the root canals were completely filled with medicaments and a cotton pellet dipped in medicament was also placed in the pulp chamber. Spectrophotometric readings were obtained from the mid-buccal surface of the tooth crowns immediately after placing the medicaments (T1) and at 1 week (T2), 1 month (T3), and 3 months (T4) after filling. The ∆E was then calculated. Data were analyzed using 2-way analysis of variance (ANOVA), 3-way ANOVA, and the Scheffé post hoc test. RESULTS: The greatest color change (ΔE) was observed at 3 months (p < 0.0001) and in 3Mix subgroup B (p = 0.0057). No significant color change occurred in the CH (p = 0.7865) or CH/CHX (p = 0.1367) groups over time, but the 3Mix group showed a significant ΔE (p = 0.0164). CONCLUSION: Intracanal medicaments may induce tooth discoloration. Use of 3Mix must be short and it must be carefully applied only to the root canals; the access cavity should be thoroughly cleaned afterwards.

Effect of Smear Clear and Conventional Root Canal Irrigants on Push-Out Bond Strength of Resilon/Epiphany System.

Introduction: The aim of the present study is to compare the effect of SmearClear and sodiumhypochlorite (NaOCl), chlorhexidine (CHX) and normal saline (NS) on the push-out bond strength of Resilon/Epiphany system to dentine. Methods and Materials: In this in vitro study; 48 single-rooted teeth were selected and decoronated from the CEJ. Then the specimens were divided into four groups (n=12). The roots were prepared by single length technique using MTwo rotary system. The final irrigations of the canals were done using 2% CHX, normal saline, 5.25% NaOCl or SmearClear. The canals were obturated by Resilon/Epiphany system. The teeth were cut perpendicular to their longitudinal axis and four 1-mm-thick sections were obtained from coronal and mid root regions. The push-out bond strength of Resilon/Epiphany system to dentin were calculated and bond failure patterns were assessed. The data were subjected to two-way analysis of variance and Tukey's tests. Results: The highest bond strength values were reported for SmearClear and the lowest values for the NS solutions. The effects of irrigant type (P<0.05) and canal area (P<0.0001) on the bond strength of Resilon to dentin were significant (P<0.05). Higher bond strength values were obtained in the mid root areas compared to the coronal regions. In two-by-two comparisons, significant differences in bond strength were found between SmearClear and normal saline (P<0.05) while the other irrigants showed no significant differences (P>0.05). Conclusion: SmearClear solution was able to increase the push-out bond strength of Resilon to the dentin similar to other irrigants (NaOCl and CHX). Therefore, it can be used for the root canal irrigation and smear layer removal in the clinical situations.

Management of an Endodontic-Periodontal Lesion in a Maxillary Lateral Incisor with Palatal Radicular Groove: A Case Report.

UNLABELLED: The radicular groove is a developmental anomaly that predisposes the tooth to periodontal break-down. Sometimes the situation becomes more complicated by pulp necrosis and development of a combined endodontic-periodontal lesion which is a diagnostic and treatment challenge for the clinician. This report presents the successful management of an endodontic-periodontal lesion in a maxillary lateral incisor that has a developmental palatal radicular groove using a combination of nonsurgical endodontic therapy and periodontal regenerative techniques. CONCLUSION: The combination of nonsurgical endodontic and periodontal regenerative treatment is a predictable method in treating combined endodontic-periodontal lesions caused by palato-gingival groove.

Antibacterial Activity of Diode Laser and Sodium Hypochlorite in Enterococcus Faecalis-Contaminated Root Canals.

INTRODUCTION: The aim of the present in vitro study was to evaluate the disinfection ability of 980-nm diode laser in comparison with sodium hypochlorite (NaOCl) as a common root canal irrigant in canals infected with Enterococcus faecalis (E. faecalis). METHODS AND MATERIALS: The root canals of 18 extracted single-rooted premolars were prepared by rotary system. After decoronation, the roots were autoclaved. One specimen was chosen for the negative control, and the remaining teeth were incubated with E. faecalis suspension for two weeks. Subsequently, one specimen was selected as the positive control and the remaining samples were divided into two groups (n=8). The samples of the first group were irrigated with 5.25% NaOCl and the second group were treated with a 980-nm diode laser. Microbial samples were taken from the root canals and bacterial cultivation was carried out. The average value and the standard deviation of colony-forming units (CFU) of each specimen were measured using descriptive statistics. The student's t-test was used to compare the reduction in CFU in each group. The equality of variance of CFU was measured by the Levene's test. RESULTS: NaOCl resulted in 99.87% removal of the bacteria and showed significantly more antibacterial effect compared to the 980-nm diode laser which led to 96.56% bacterial reduction (P<0.05). CONCLUSION: Although 5.25% NaOCl seems to reduce E. faecalis more effectively, the diode laser also reduced the bacterial count. Therefore a 980-nm diode laser could be considered as a complementary disinfection method in root canal treatment.

Evaluation of relationship between oral health-related quality of life and occlusion traits among female adolescents.

BACKGROUND: The aim of this study was to determine the impact of malocclusions on oral health-related quality of life (OHRQOL) among female adolescents. MATERIALS AND METHODS: This is an observational cross-sectional descriptive study. A total of 129 female students with age ranges between 14 and 17 years old were randomly selected from Mashhad (Iran) high schools and were asked to fill out an OHRQOL questionnaire included in four parts: Oral symptoms, functional limitations, emotional well-being and social well-being. Each participant was clinically examined to assess her malocclusion according to the index of complexity, outcome and need (ICON) and finally the data were entered to SPSS 11.5 and the relation between these two variables was assessed with Pearson correlation test. P < 0.05 was considered as statistically significant. RESULTS: There was statistically significant correlation between ICON scores and quality of life (P = 0.0176). Being separately assessed, among four parts of the questionnaire, only emotional well-being was significantly correlated with the ICON score (P < 0.05). CONCLUSION: Malocclusions play a vital role in OHRQOL. However, in female adolescents among four parts of OHRQOL, emotional well-being had significant relationship with malocclusions.

Sealing ability of mineral trioxide aggregate and calcium-enriched mixture cement as apical barriers with different obturation techniques.

INTRODUCTION: Endodontic treatment in pulpless immature teeth is challenging due to the lack of an apical stop. Insertion of an apical plug is an alternative to conventional long-term apexification with calcium hydroxide. The aim of this study was to compare the apical microleakage of mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement as apical plugs with three different obturation techniques. METHODS AND MATERIALS: This experimental study was conducted on 130 single rooted human teeth with one canal. Samples were randomly divided into 2 experimental groups (n=60) and two negative and positive control groups containing 5 samples each. After cleaning and shaping, an open apex configuration was prepared in all samples. MTA or CEM cement apical plugs with 5 mm thicknesses were placed. Then, each group was divided to 4 subgroups and the remaining space of root canals were filled with either lateral compaction or thermoplasticized injectable gutta-percha or was obturated by filling the entire canal with apical plug material. In one remaining subgroup the canal space was left unfilled. Microleakage was measured by the fluid filtration method and results were analyzed by means of the two-way ANOVA test. RESULTS: There were no significant differences between microleakage of MTA and CEM cement apical plugs (P=0.92). The difference between three obturation methods was not significant, either (P=0.39). CONCLUSION: MTA and CEM cement have similar sealing ability as apical plugs and no significant difference was found in microleakage of the three groups.