Effect of photobiomodulation on postoperative endodontic pain: A systematic review of clinical trials.

Background: This review aims to perform a complete evaluation of the impact of photobiomodulation (PMB) on postoperative endodontic pain. Materials and Methods: The PRISMA checklist was used to perform this systematic review. The electronic databases were searched, including Google Scholar, PubMed, and Embase. Sixty-three papers were obtained through a main electronic search and a hand search. Nine trials met the criteria after screening the titles, abstracts, and/or full texts. Results: Seven out of nine studies showed that PMB has a significant impact on relieving postoperative endodontic pain, with no statistically significant difference in the severity of pain between the laser and control groups in the two remaining studies. In addition, eight studies showed no adverse effects, indicating that we can remove the adverse effects of drugs such as nonsteroidal anti-inflammatory drugs. However, one study showed evidence of the consequences of PMB application on teeth with symptomatic irreversible pulpitis. Therefore, it can be concluded that PMB should not be used in teeth with pain because of irreversible pulpitis. Conclusion: Although there is some understanding from a cellular viewpoint of the effects of PMB, there is still some uncertainty about whether these cell-level modifications impact reducing the postendodontic pain.

Comparison of the success of inferior alveolar nerve anesthesia in the mandibular first molars with symptomatic irreversible pulpitis using two anesthetic solutions of prilocaine and mepivacaine: A randomized controlled clinical trial.

Background: This study aimed to compare the success rate of inferior alveolar nerve (IAN) anesthesia in the mandibular first molars with symptomatic irreversible pulpitis using two anesthetic solutions of prilocaine and mepivacaine. Materials and Methods: The current randomized controlled clinical trial was conducted on 100 patients in two groups (n = 50). Standard injection of IAN block (IANB) was performed using two cartridges of 3% mepivacaine plain in the first group and using two cartridges of 3% prilocaine with 0.03 IU felypressin in the second group. Fifteen minutes after injection, the patients were asked about lip anesthesia. In case of a positive answer, the tooth was isolated with a rubber dam. Success was defined as no or mild pain on the basis of the visual analog scale recording upon access cavity preparation, entry into the pulp chamber, and initial instrumentation. Data were analyzed with SPSS 17 using the Chi-square test, and P < 0.05 was set as statistically significant. Results: The patients' pain severities during the three stages were significantly different (P = 0.001, 0.0001, and 0.001, respectively). The success rate of IANB during access cavity preparation was 88% with prilocaine and 68% with mepivacaine. This rate during entry into the pulp chamber was 78% and 24%, respectively, which was 3.25 times higher with prilocaine than mepivacaine. The success rates during instrumentation were 32% and 10%, respectively, which was 3.2 times higher with prilocaine than mepivacaine. Conclusion: The success rate of IANB in the teeth with symptomatic irreversible pulpitis was higher using 3% prilocaine with felypressin than using 3% mepivacaine.

Effect of Incorporating Hydroxyapatite and Zinc Oxide Nanoparticles on the Compressive Strength of White Mineral Trioxide Aggregate.

STATEMENT OF THE PROBLEM: Many efforts have been made to improve the properties of mineral trioxide aggregate (MTA), including the incorporation of nanoparticles. PURPOSE: The aim of this study was to investigate the incorporation of zinc oxide and hydroxyapatite nanoparticles on the compressive strength of white MTA (WMTA). MATERIALS AND METHOD: In this in vitro study, the following materials were evaluated: MTA, MTA+5% zinc oxide (ZnO) nanoparticles, MTA+10% zinc oxide nanoparticles, MTA+5% hydroxyapatite (HA) nanoparticles, MTA+10% zinc oxide nanoparticles. The compressive strength of the groups under investigation was measured on days 4 and 21 after mixing the MTA using a universal testing machine. Two-way ANOVA test was used to compare the groups and determine the significance of the effect of time and material on the compressive strength (p<0.05). RESULTS: The highest and lowest compressive strength values were respectively measured for the second group, MTA/21 days, and the fourth group, MTA+Nano ZnO/4 days. Two-way ANOVA indicated that incorporation of zinc oxide and hydroxyapatite nanoparticles into MTA did not have a significant effect on compressive strength (p= 0.05). Compressive strength in all the groups increased over time from day 4 to day 21. However, this increase was not statistically significant (p= 0.06) except for the MTA group, which exhibited significant increase in compressive strength over time from day 4 to day 21 (p=0.007). CONCLUSION: Incorporation of HA and ZnO nanoparticles into MTA had no detrimental effects on its strength and these nanoparticles can be used to improve the other properties of MTA.

Efficacy of mental-incisive nerve block in root canal treatment of mandibular first molars with asymptomatic irreversible pulpitis: a randomized controlled trial.

The aim of this study was to evaluate the effect of mental-incisive nerve block (MINB) along with finger pressure following inferior alveolar nerve block (IANB) on anesthetic success in mandibular first molars with asymptomatic irreversible pulpitis. In this randomized controlled trial, 70 patients were randomly divided into 2 groups (n = 35). Each patient in the control group received only a standard IANB injection of 1.8 mL of 2% lidocaine with 1:100,000 epinephrine. The injection was administered within 1 minute, using a standard aspirating dental cartridge fitted with a 27-gauge dental needle. In the intervention group, 15 minutes after injection of the standard IANB as described for the control group, each patient received a standard MINB injection of 1 mL of 2% lidocaine containing 1:100,000 epinephrine, administered by an operator not involved in assessing the outcomes. After the MINB injection, the patient applied firm finger pressure to the soft tissue of the mental foramen region for 1 minute using the hand on the side opposite to the injection. Objective assessment of tooth anesthesia was carried out with electric pulp tests (EPTs). In addition, the patients rated their pain during the initial steps of endodontic treatment based on a visual analog scale (VAS). The Mann-Whitney U and Wilcoxon tests were used for the analysis of data. Of the 35 patients in each group, 20.0% (7 patients) in the control group and 71.4% (25 patients) in the intervention group had no response to EPTs 15 minutes after injections; this difference was statistically significant (P < 0.05). The VAS pain scores were significantly higher in the control group than in the intervention group (P = 0.001). The administration of MINB with pressure following IANB significantly improved the success of anesthesia in mandibular first molars with asymptomatic irreversible pulpitis.

Evaluation of the film thickness and antibacterial property of mineral trioxide aggregate mixed with propylene glycol as a root canal sealer.

BACKGROUND: The aim of this in vitro study was to compare the film thickness and antibacterial properties of mineral trioxide aggregate-propylene glycol (MTA-PG) as a sealer in comparison with MTA Fillapex and AH26 sealers. MATERIALS AND METHODS: In these in vitro study the antibacterial property of the sealers was evaluated using direct contact test in fresh and set states. Enterococcus faecalis was incubated in direct contact with fresh and set materials. The growth of exposed bacteria was evaluated by counting colony-forming units (CFUs) after 10 min and 1 h in the culture medium. The film thickness of sealers was measured according to the International Standard Organization 6876/2012. The data were statistically analyzed using an independent t-test and repeated measures of ANOVA. The level of significance was set at 0.05. RESULTS: CFU means in AH26 was significantly more than other groups (P < 0.0001), but there was no difference between MTA-PG and MTA Fillapex. The mean of CFUs in set AH26 after 1 h exposure was significantly >10-min exposure (P = 0.006). The mean film thickness values of MTA Fillapex, MTA-PG, and AH26 were 57.3, 50.9, and 78.3 µm, respectively. CONCLUSION: MTA-Fillapex and MTA-PG showed distinct antibacterial effect. AH26 showed more antibacterial effect in fresh state in comparison with set state. The film thickness of MTA-PG and MTA-Fillapex was significantly less than AH26.

The Effect of in Vitro Sample Preparation Methods on Bond Strength of Mineral Trioxide Aggregate to Root Dentin.

Introduction: The aim of this study was to compare the effect of sample preparation methods on push-out bond strength of mineral trioxide aggregate (MTA). Methods and Materials: Twenty-four extracted human mandibular premolars with single root canal were selected for this in vitro study. After instrumentation, irrigation and drying of root canals, they were randomly divided into two experimental groups (n=12). Group 1: After removing the 3 mm of root ends, 2 mm thick sections were established from the remaining roots. MTA was mixed following the manufacturers' recommendations and root sections were filled. Group 2: The whole root canal was used for filling and packing of MTA and like group 1, after removing the 3 mm of root ends, root sections were provided. Push-out bond strength was measured and analyzed by the independent t-test. Level of statistical significance was set at 0.05. Results: The highest mean push-out bond strength was in apical section of group 2 (4.86±1.31) and the lowest value was in coronal section of group 2 (3.05±1.15). The results of the independent t-test showed a significant difference between two groups only in the apical section (P=0.02). Conclusion: Based on the results of this in vitro study, the highest mean push-out bond strength was in apical section of group 2. It seems that using the whole root canal for MTA application is better for MTA in vitro analysis of bond strength to root dentin because it is more similar to the clinical conditions.

Effect of Casein Phosphopeptide Amorphous Calcium Phosphate Conditioning on Microtensile Bond Strength of Three Adhesive Systems to Deep Dentin.

Objectives: This study aimed to assess the effect of casein phosphopeptide amorphous calcium phosphate (CPP-ACP) on microtensile bond strength of three adhesive systems to deep dentin. Materials and Methods: In this in vitro study, the occlusal surface of 30 sound human third molars was sectioned at 2 mm below and above the cementoenamel junction. The samples were randomly divided into three groups of OptiBond Solo Plus, G-Bond, and Clearfil SE Bond. Before composite resin bonding, each group was divided into two subgroups with and without dentin preparation with CPP-ACP. The teeth were then sectioned into 1 mm rods (n=15), and their microtensile bond strength was measured at a crosshead speed of 0.5 mm/min. Data were analyzed using two-way ANOVA and post-hoc Bonferroni test. Results: There was no significant difference in bond strength of OptiBond Solo Plus (P=0.44) and Clearfil SE Bond (P=0.67) with/without CPP-ACP. A significant difference was found between the two subgroups of G-Bond in this respect (P<0.001). The differences in microtensile bond strength among all subgroups were significant (P<0.05). Conclusion: The microtensile bond strength in use of G-Bond is significantly higher following dentin treatment with CPP-ACP compared with no use of CPP-ACP.

Evaluation of sealing abilitiy of mineral trioxide aggregate mixed with propylene glycol as a root canal sealer: A in vitro study.

BACKGROUND: Sealing ability is one of the most important features of endodontic sealers. The main goal of the present study was to compare sealing ability of mineral trioxide aggregate (MTA)-propylene glycol (PG) with two commonly used resin-based and MTA-based sealers. MATERIALS AND METHODS: In This in vitro study Seventy extracted single-root teeth were used. Canal preparation was carried out using hand and RaCe rotary files. Ten teeth were used as control. The root canals in positive and negative control groups were left empty. Remaining 60 teeth were randomly divided into following four groups (n = 15): In Group 1, the canals were dried using paper cones and obturated using MTA-PG sealer. In Group 2, saline was removed from canal using a syring, but paper cones were not used. Obturation was done using MTA-PG sealer. In Groups 3 and 4, the canals were dried using paper cones and obturated with AH26 and MTA Fillapex, respectively. Two-chamber method was used to evaluate bacterial leakage using Enterococcus faecalis (ATCC 29212). Turbidity of the lower chambers was checked every day during 90 days. Chi-square, Kaplan-Meier analysis, and logrank tests were used to compare groups regarding leaked samples at the end of the study. The level of significance was set at 0.05. RESULTS: There was no significant difference among groups regarding rate of leakage throughout the study. However, at the end of the study, the groups were statistically different regarding leaked samples (P = 0.034). MTA Fillapex and MTA-PG in dry canal showed the most and least leaked samples at the end of the study, respectively (P < 0.05). CONCLUSION: MTA mixed with PG has superior sealing ability than MTA Fillapex.

Anesthetic efficacy of articaine/epinephrine plus mannitol in comparison with articaine/epinephrine anesthesia for inferior alveolar nerve block in patients with symptomatic irreversible pulpitis: A randomized controlled clinical trial.

Background. It is difficult to achieve successful pulpal anesthesia in mandibular posterior teeth with symptomatic irreversible pulpitis. The present study aimed to compare the effect of articaine/epinephrine anesthesia with articaine/epinephrine at a combination of 0.5 mol/mL of mannitol for the inferior alveolar nerve block (IANB) in patients presenting with symptomatic irreversible pulpitis in the mandibular first molar tooth. Methods. One hundred patients with symptomatic irreversible pulpitis in the mandibular first molar tooth were selected and randomly divided into two groups based on the injection method. The first group underwent an IANB technique with 1.8 mL of articaine, whereas the second group received 2.9 mL of a formulation, consisting of 1.8 mL of articaine plus 1.1 mL of 0.5 mol/L of mannitol. Fifteen minutes after injections and anesthesia of the lip, the access cavity was prepared. According to the visual analog scale (VAS) criteria, no pain or mild pain for caries removal, pulp exposure and canal instrumentation were regarded as success. Chi-squared test was used for the analysis of data. The level of significance was set at 0.05. Results. The success rate in the group with articaine/epinephrine anesthesia plus mannitol was higher than that in the group with articaine/epinephrine anesthesia, with no significant difference between the two groups (P>0.05). Conclusion. It was concluded, under the limitations of this study, that adding mannitol to articaine/epinephrine anesthesia did not increase the success of IANB in mandibular posterior teeth with symptomatic irreversible pulpitis.

Effect of non-surgical periodontal therapy on concentrations of salivary biomarkers in patients with chronic periodontitis: A clinical trial.

Background: Certain salivary biomarkers that are considered unique in relation to the physiological aspects of periodontitis can be helpful in the diagnosis of periodontitis by considering quantitative changes in such biomarkers. This study was undertaken to answer the question to what extent non-surgical periodontal treatment can affect concentrations of salivary biomarkers in patients suffering from chronic periodontitis. Methods: Eighteen patients with generalized moderate-to-severe chronic periodontitis were recruited for this study by considering periodontal parameters of gingival index (GI), probing pocket depths (PPD), clinical attachment levels (CAL) and a number of radiographic parameters. Salivary samples were analyzed at baseline and at one-month interval after non-surgical periodontal treatment consisting of scaling and root planing. Concentrations of salivary biomarkers, including cortisol, immunoglobulin A (Ig A), IL-6, interferon-γ, soluble intercellular adhesion molecule-1 (sICAM) and ALP, were determined with the use of an ELISA kit. Data were subjected to statistical analyses using paired t-test, with SPSS 15. Statistical significance was set at P<0.05. Results: Mean levels of IgA and interferon-γ decreased significantly after treatment (P<0.05); however, cortisol concentrations increased significantly after treatment. In addition, the decrease in IL-6, sICAM-1 and ALP levels were not significant (P>0.05). Conclusion: The results showed that the salivary levels of IgA and interferon-γ decreased and those of cortisol increased significantly subsequent to scaling and root planing.

Antibacterial Effect of Two Nano Zinc Oxide Gel Preparations Compared to Calcium Hydroxide and Chlorhexidine Mixture.

INTRODUCTION: The aim of this study was to compare the antibacterial effects of two gels containing zinc oxide and zinc oxide/silver nanoparticles and a mixture of calcium hydroxide and 0.12% chlorhexidine as intracanal medicaments in root canals contaminated with Enterococcus faecalis (E. faecalis) at different time intervals. METHODS AND MATERIALS: After preparation and culturing of E. faecalis in 132 single root teeth, the initial count of bacteria was performed. Then, different materials as intracanal medicaments were used in periods of 3, 7 and 14 days (group 1: calcium hydroxide with 0.12% CHX paste; group 2 zinc oxide nanoparticles gel; group 3: zinc oxide/silver nanoparticles gel; group 4: normal saline as the control group). After the specified time, intracanal medicament was removed and the final count of bacteria was performed. Antibacterial effect of materials was counted by measuring the percentage reduction in the colony counts (RCC). Data were analyzed using the descriptive statistics (Mean±SD) and multi-factorial analysis of variance (by taking into account the effect of the time factor on the dependent variable). RESULTS: There were no statistically significant differences among mean RCC of different time intervals in each group (P=0.09). However, the differences in mean RCC of different dressing materials were significant (P<0.001). The effect of interaction between time and materials was significant (P=0.015). Comparison of the antibacterial effects of experimental agents at different time intervals showed that the mean RCC in group 1 was higher than other groups (P<0.001). The difference in antibacterial effect between groups 2 and 3 was not significant (P>0.05). The minimum antibacterial effect was observed in group 4 (P<0.0001). CONCLUSIONS: The mixture of calcium hydroxide/chlorhexidine as an intracanal medicament was more effective than zinc oxide and zinc oxide/silver nanoparticles gels.

In Vitro Sealing Properties of Calcium-Enriched Mixture and Mineral Trioxide Aggregate Orifice Barriers during Intra-Coronal Bleaching.

INTRODUCTION: This study aimed at evaluating the sealing properties of calcium-enriched mixture (CEM) compared to mineral trioxide aggregate (MTA) as a cervical barriers in intra-coronal bleaching. METHODS AND MATERIALS: In this in vitro study, endodontic treatment was performed on 60 extracted human incisors and canines without canal calcification, caries, restorations, resorption or cracks. The teeth were then randomly divided into two experimental groups and two control groups (n=15). Then, CEM cement and MTA were applied as 3-mm intra-orifice barriers in the test groups; a mixture of sodium perborate and 30% hydrogen peroxide bleaching agents were placed within the pulp chamber for one week. Dye penetration method was used to evaluate the sealing ability of agents. Statistical analysis was performed using SPSS software. The Kendall coefficient was used to evaluate inter-observer agreement. The chi-squared test was used for statistical analysis. RESULTS: The results showed that the penetration rates of CEM and MTA were the same as positive control group, with no significant differences (P=0.673 and P=0.408, respectively). However, there was a significant difference between the negative control group and CEM and MTA groups (P=0.001 for both groups). In addition, the sealing ability of MTA and CEM cement were not significantly different (P=0.682). CONCLUSION: During intra-coronal bleaching procedures CEM cement can be used as a cervical barrier with sealing properties comparable to that of MTA.

Antibacterial Efficacy of Different Concentrations of Sodium Hypochlorite Gel and Solution on Enterococcus faecalis Biofilm.

INTRODUCTION: This in vitro study compared the antibacterial efficacy of 2.5% sodium hypochlorite gel and 2.5% and 5.25% sodium hypochlorite solutions on Enterococcus faecalis (E. faecalis) biofilm. METHODS AND MATERIALS: The root canals of 60 extracted human single-rooted teeth were contaminated with E. faecalis and incubated for 6 weeks. The samples were randomly assigned to three experimental groups and one control group (n=15). The study protocol in the experimental groups consisted of injection of 5 mL of each irrigant into the root canals. Samples were collected from the root canal walls and 1:10 serial dilutions were prepared and added to Muller Hinton Agar (MHA) plates and incubated at 37°C for 48 h. A classic colony counting technique was used for determining vital E. faecalis bacterial counts in MHA plates. The Kruskal-Wallis test was used for statistical analysis of the data. The level of significance was set at 0.05. RESULTS: The antibacterial effect of the irrigants in all three experimental groups was significantly greater than the control group (P<0.05), with no significant difference between 2.5% and 5.25% NaOCl solutions (P>0.05). The effect of 2.5% and 5.25% NaOCl solutions were significantly superior to 2.5% NaOCl gel (P<0.05). CONCLUSION: Under the limitations of this study, 2.5% NaOCl gel was effective in reducing E. faecalis counts; however this effect was less than that of NaOCl solutions.

The Antibacterial Efficacy of Photo-Activated Disinfection, Chlorhexidine and Sodium Hypochlorite in Infected Root Canals: An in Vitro Study.

INTRODUCTION: This study compared the efficacy of light-activated low-power laser, 2% chlorhexidine (CHX) and 2.5% NaOCl in eliminating Enterococcus faecalis (E. faecalis) from the root canal system. METHODS AND MATERIALS: The root canals of 60 maxillary central incisors were contaminated with E. faecalis and then the bacteria were incubated for 24 h. All the root canals were instrumented in a crown-down manner with #4 and 3 Gates-Glidden drills, followed by RaCe rotary files (40/0.10, 35/0.08, and 30/0.06). The samples were randomly assigned to three experimental groups and one control group (n=15). In the control group no intervention was made. In the photo-activated disinfection (PAD) group, laser therapy was undertaken with diode laser beams (with an output power of 100 mW/cm(2)) for 120 sec. For the other two experimental groups, root canals were irrigated either with 5 mL of 2% CHX or 2.5% NaOCl solutions, respectively. The Kruskal-Wallis test was used to compare the CFU values of the bacteria and post-hoc Bonferroni test was used for pairwise comparisons. The level of significance was set at 0.05. RESULTS: The inhibition of bacterial growth in all the experimental groups was significantly superior to the control group (P<0.05). There was no significant difference between the effect of PAD and 2% CHX (P=0.05). The effect of 2.5% NaOCl was significantly better than that of the PAD technique (P<0.001). In addition, 2.5% NaOCl was significantly better than 2% CHX (P=0.007). CONCLUSION: Photodynamic therapy was effective in reducing the E. faecalis counts in comparison with the control group, but 2.5% NaOCl solution was the most effective protocol.

Radiographic evaluation of root canal fillings accomplished by undergraduate dental students.

INTRODUCTION: The purpose of this study was to evaluate the radiographic quality of root canal fillings by fourth-, fifth-, and sixth-year undergraduate students at Tabriz Faculty of Dentistry between 2006 and 2012. METHODS AND MATERIALS: A total of 1183 root canal fillings in 620 teeth were evaluated by two investigators (and in case of disagreement by a third investigator) regarding the presence or absence of under-fillings, over-fillings and perforations. For each tooth, preoperative, working and postoperative radiographs were checked. The Pearson's chi-square test was used for statistical evaluation of the data. Inter-examiner agreement was measured by Cohen's kappa (k) values. The level of significance was set at 0.05. RESULTS: Total frequencies of over-filling, under-filling and perforation were 5.6%, 20.4% and 1.9%, respectively. There were significant differences between frequencies of over- and under-fillings (P<0.05). Unacceptable quality, under- and over-fillings were detected in 27.9% of 1183 evaluated canals. CONCLUSION: The technical quality of root canal therapies performed by undergraduate dental students using step-back preparation and lateral compaction techniques was unacceptable in almost one-fourth of the cases.

Varicella Zoster Virus and Internal Root Resorption: A Case Report.

Herpes zoster is a viral infection caused by the reactivation of the varicella zoster virus. One of the less well-recognized maxillofacial complications is tooth root resorption. To our knowledge, this is the first case report about internal resorption associated with varicella zoster virus involving different dental quadrants. A 38-year-old woman presented with internal resorption of maxillary canine and first premolar tooth roots on the right quadrant and generalized internal resorption of second molars of both mandibular quadrants. The patient's medical history showed mild oral lichen planus and infection with varicella zoster virus (chickenpox) with severe clinical manifestations 5 years previously. The patient developed diabetes mellitus type I and hypothyroidism a short time after varicella zoster virus infection, and by the time of infection with this virus, oral lichen planus had progressed from the reticular pattern to the generalized severe erosive form. Viral etiology could also be considered in these diseases. The root canals of the affected teeth were debrided, irrigated, and dried, and calcium hydroxide paste was placed in the root canals for a week during the first treatment session. The root canals were obturated during the second session. Six-month follow-up showed improvement of oral lichen planus and resolution of widening of periodontal ligament of the affected teeth, with follow-up radiographs revealing no periapical problems. It appears some cases of internal root resorption classified as idiopathic might have viral etiology. Therefore, it is recommended that patients be questioned about a history of chickenpox and herpes zoster.

Laser application in prevention of demineralization in orthodontic treatment.

One common negative side effect of orthodontic treatment with fixed appliances is the development of incipient caries lesions around brackets, particularly in patients with poor oral hygiene. Different methods have been used to prevent demineralization such as fluoride therapy and application of sealant to prevent caries. The recent effort to improve the resistance against the demineralization is by the application of different types of lasers. The purpose of this review article is discussing the effects of laser in prevention of demineralization in orthodontic patients.