Effect of calcium hydroxide mixed with lidocaine hydrochloride on postoperative pain in teeth with irreversible pulpitis and symptomatic apical periodontitis: a preliminary randomized controlled prospective clinical trial.

OBJECTIVES: To investigate the effect of calcium hydroxide mixed with lidocaine HCl on postoperative spontaneous pain. MATERIALS AND METHODS: Sixty patients having irreversible pulpitis and symptomatic apical periodontitis with a preoperative spontaneous pain and percussion pain which was more than 50 on a visual analogue scale (100 mm VAS) were included in this study. After the preparation of the root canals, the patients were randomly distributed into two groups according to the calcium hydroxide vehicle, control group (mixed with saline) and calcium hydroxide mixed with lidocaine HCl (n = 30). Postoperative spontaneous pain scores were recorded by a VAS every day for a week. Data were analysed using one-way analysis of variance, chi-squared test and Mann-Whitney U tests (p = 0.05). RESULTS: The calcium hydroxide mixed with lidocaine HCl group resulted in significantly less pain compared with the calcium hydroxide mixed with saline group during days 1 to 4 (p < 0.05). There were no significant differences between the groups in terms of postoperative percussion pain levels (p > 0.05). CONCLUSION: Within the limitations of this study, it can be concluded that the calcium hydroxide mixed with lidocaine HCl can be beneficial in reducing postoperative pain in teeth with irreversible pulpitis and symptomatic apical periodontitis. CLINICAL RELEVANCE: The calcium hydroxide mixed with lidocaine HCl can be beneficial in reducing postoperative pain in teeth with irreversible pulpitis and symptomatic apical periodontitis. CLINICAL REGISTRATION NUMBER: TCTR20181121003.

The effect of taper and apical preparation size on fracture resistance of roots.

This study investigated the effect of taper and apical preparation size on the fracture resistance of roots. 84 mandibular incisor teeth were selected. Groups (n = 12): uninstrumented (control group), 25/0.04, 25/0.06, 25/0.08, 30/0.04, 30/0.06 and 30/0.08. K3XF files (Kerr Endodontics, Orange, CA) were used for canal preparation. Fracture resistance was tested using a Universal test machine. For statistical analysis, the level of significance was P ≤ 0.05, and one-way anova and post hoc LSD tests were used. The control group showed the highest fracture resistance (P < 0.05). No significant difference was found between 25/0.04 and 25/0.06; 25/0.06 and 25/0.08; 30/0.04 and 30/0.06; 30/0.06 and 30/0.08; 25/0.04 and 30/0.04; 25/0.06 and 30/0.06; and 25/0.08 and 30/0.08 (P > 0.05). Significant differences were found between 25/0.04 and 25/0.08; 30/0.04 and 30/0.08; and 25/0.08 and 30/0.04 (P < 0.05). In conclusion, the clinical selection of larger tapers can cause a higher risk of fracture.

Effect of different laser-assisted irrigation activation techniques on apical debris extrusion.

Objective: The aim of this study was to compare apical debris extrusion when neodymium-doped yttrium aluminium garnet (Nd:YAG) lasers, erbium-doped yttrium aluminium garnet (Er:YAG) or photon-induced photoacoustic streaming (PIPS) are used for irrigation activation.Materials and methods: A total of 60 extracted human mandibular premolar teeth have similar dimensions were included and the samples were split into four groups according to the irrigation technique (n = 15): conventional needle irrigation, PIPS, Er:YAG and Nd:YAG. ProTaper Universal system up to F4 was used for root canal instrumentation. Bidistilled water was used as an irrigation solution during instrumentation and irrigation activation. Apically extruded debris was collected into preweighed Eppendorf tubes during instrumentation and irrigation activation procedures. The tubes were then kept in an incubator at 70 °C for 5 days. The initial weight of the tube was subtracted from the final weight and the result was recorded as the weight of dry extruded debris. The data were evaluated statistically using a one-way ANOVA test followed by least significant difference post hoc test (p < .05).Results: Conventional needle irrigation caused significantly less debris extrusion than laser-assisted irrigation activation groups (p < .05). Laser-assisted irrigation activation groups caused statistically similar debris extrusion (p > .05).Conclusion: Laser-assisted irrigation activation techniques caused more debris extrusion when compared to conventional needle irrigation.

Effects of continuous irrigation at room temperature or +4ºC on the cyclic fatigue resistance of K3XF instruments.

Background. The present study aimed to evaluate the impact of continuous irrigation with saline solution at room temperature or +4°C on the cyclic fatigue resistance of K3XF files. Methods. Forty-eight new K3XF files (#30, .04 taper) were randomly assigned to three groups: control group (no irrigation), continuous irrigation with saline solution at room temperature, and continuous irrigation with saline solution at +4°C. The instruments were tested in an artificial, stainless steel root canal with a double curvature at body temperature (37±1°C). Time to fracture was converted to the number of cycles to fracture (NCF). The lengths of the fractured fragments were recorded. Kruskal-Wallis H test and one-way ANOVA were used to analyze data. Results. K3XF files' cyclic fatigue resistance was significantly higher in the continuous irrigation groups than in the control group. Continuous irrigation with saline solution at +4°C resulted in higher cyclic fatigue resistance than continuous irrigation with saline solution at room temperature. There were no significant differences between the groups in terms of the fractured fragments' length. Conclusion. Within this study's limitations, continuous irrigation with saline solution increased the NCF of NiTi instruments; decreasing the saline solution's temperature increased this effect.

Duration of ultrasonic activation causing secondary fractures during the removal of the separated instruments with different tapers.

OBJECTIVES: The aim of the present study was to determine the effect of taper (.08, .06, and .04) of separated K3XF instruments on duration taken for the secondary fracture formation during ultrasonic activation. MATERIALS AND METHODS: Ten 25/.08 K3XF (SybronEndo, Orange, CA, USA), ten 25/.06 K3XF, and ten 25/.04 K3XF instruments were used for the study. The apical 5 mm of the instruments was cut to simulate the fragments in root canals. Fragments of the instruments were sandwiched between two straight dentin blocks. An ultrasonic tip was used to cause a secondary fracture of the fragment. The time needed for the secondary fracture was recorded for each instrument. The data were statistically analyzed using the Kruskal-Wallis H test (alpha = 0.05). RESULTS: Secondary fractures occurred in all instruments. In the .08 taper group, secondary fractures took longer than in the case of the .06 and the .04 taper groups (P < 0.05). There were no significant differences between the .06 and the .04 taper groups in terms of the time required for the occurrence of a secondary fracture (P > 0.05). CONCLUSIONS: In the .08 taper group, secondary fracture took longer time than in the case of the .06 and the .04 taper groups due to its larger cross-sectional area involved. CLINICAL RELEVANCE: Typically, when removing separated instruments, a much lower power setting is chosen. The purpose of this in vitro study was to determine which tapered files were more resilient to secondary fracture, thus allowing a higher power setting to be chosen. Thus, the results of the present study cannot be used in clinical practice. If the clinician knows the taper of the broken file, the clinician should be very careful with regard to secondary fractures when using ultrasonics to remove the separated smaller tapered instruments.

Effect of Super-Bond C&B and self-adhesive dual-cured resin cement on the fracture resistance of roots with vertical root fracture.

Background. Vertical root fracture might occur during root canal preparation, obturation, post procedures or endodontic treatment. Methods. Fifty-four single-rooted human teeth were decoronated to obtain a standardized length. The root canals were enlarged up to #50 and obturated with gutta-percha and root canal sealer. Eighteen teeth were used as a control group, and vertical root fracture was induced in the remaining teeth. The samples were randomly divided into three groups, as follows: control group (without vertical root fracture), Super-Bond C&B group (fragments were attached with Super-Bond C&B), and self-adhesive dual-cured resin cement group (fragments were attached with self-adhesive dual-cured resin cement). Each specimen was subjected to a fracture resistance test, and data were statistically analyzed using chi-squared test, one-way ANOVA and post hoc Tukey tests (P=0.05). Results. The fracture resistance values of the control and Super-Bond C&B groups were higher than those of the self-adhesive dual-cured resin cement group (P<0.05). However, there were no significant differences between the control and Super-Bond C&B groups (P>0.05). Conclusion. Within the limitations of the present study, Super-Bond C&B was beneficial in obtaining higher fracture resistance in endodontically treated roots with vertical root fracture.

Success of maintaining apical patency in teeth with periapical lesion: a randomized clinical study.

OBJECTIVE: The aim of this study was to evaluate the effect of maintaining apical patency on periapical healing and postoperative pain levels in teeth with necrotic pulp and apical periodontitis. METHOD AND MATERIALS: Fifty mature teeth with periapical lesions were randomly distributed into two treatment groups: patency, and nonpatency (n = 25). Patients were followed up over a 12-month period using clinical and radiographic assessments. The data were statistically analyzed using independent-samples t test and chi-square tests at a 95% confidence level (P = .05). RESULTS: Seventeen teeth in the patency group (85.0%) and 19 teeth in the nonpatency group (86.4%) were classified as being successfully treated (P = .900). CONCLUSIONS: Within the limitations of the present study, maintaining apical patency did not affect endodontic treatment outcomes.

Regenerative Endodontic Procedures in Necrotic Mature Teeth with Periapical Radiolucencies: A Preliminary Randomized Clinical Study.

INTRODUCTION: This preliminary study compared clinical and radiographic outcomes of regenerative endodontic procedures (REPs) with that of conventional root canal treatment (CRCT) in necrotic mature teeth with periapical radiolucencies. METHODS: Fifty-six mature necrotic teeth with large periapical radiolucencies were distributed into 2 groups: group 1, REPs and group 2, CRCT (n = 28/group). Clinical and radiographic follow-up assessments were undertaken up to 12 months. Statistical analysis was performed using the independent samples t test and the chi-square test, and the level of significance was set at P = .05. RESULTS: With a follow-up rate of about 73.4% of the total patients for 12 months, favorable clinical and radiographic outcomes were found in 92.3% and 80% in REPs and CRCT groups, respectively, and the difference was not statistically significant (P > .05). Half of the teeth treated with REPs responded to the electric pulp test. CONCLUSIONS: Regenerative endodontic procedures have the potential to be used as a treatment option for mature teeth with large periapical radiolucencies.

Comparison of the cyclic fatigue resistance of ProGlider, PathGlider and One G path-finding instruments.

Background . The aim of the present study was to compare the cyclic fatigue resistance of novel nickel titanium rotary pathfinding instruments. Methods . Twenty instruments were selected for each file system. A simulated stainless steel root canal, with a 90° angle of curvature and a curvature radius of 3 mm, was used for cyclic fatigue test of the ProGlider (#16, progressive taper: 0.02‒ 0.085), PathGlider (#15, taper: .03), and One G (#14, taper: .03) instruments. Statistical analyses were performed with oneway ANOVA (P=0.05). Post hoc Tukey tests were used to determine any statistically significant differences between the groups. Results . The ProGlider instruments exhibited significantly more cyclic fatigue resistance than both PathGlider and One G instruments (P<0.001). One G instruments had significantly more resistance to fracture than PathGlider instruments (P<0.05). Conclusion . ProGlider instruments had better cyclic fatigue resistance than PathGlider and One G instruments.

Effect of intracanal diode laser application and low-level laser therapy on CGRP change.

The aim of this study was to investigate the effect of a placebo, intracanal diode laser application, and low-level laser therapy (LLLT) on the change of the total amount of calcitonin gene-related peptide (CGRP) in the gingival crevicular fluid (GCF) (split-mouth study design). GCF sampling was performed on a contralateral tooth and experimental tooth (root canal-treated tooth) of thirty-nine patients. The patients were divided into three groups (n = 13), as follows: placebo (mock laser application), intracanal laser application, and LLLT. GCF sampling was repeated at the same sites (experimental and control teeth) one week after root canal treatment. The data were analyzed using the Pearson's correlation analysis and the independent-samples t-tests (p=0.05). In the placebo group, the total CGRP level changes in the GCF before and after treatment was significantly higher for experimental teeth than for control teeth (p<0.05). However, there was no significant difference between experimental and control teeth in the intracanal laser application and LLLT groups (p > 0.05). Intracanal laser application and low-level laser therapy have immunomodulation effects linked to the modulation of the total amount of CGRP in the GCF.

The effect of photobiomodulation on total amount of substance P in gingival crevicular fluid: placebo-controlled randomized clinical trial.

To investigate the effect of photobiomodulation (PBM) and placebo on total amount of substance P in gingival crevicular fluid (GCF) pre- and postoperatively. Twenty-six patients having tooth with symptomatic apical periodontitis were enrolled in this study. GCF was collected preoperatively. The patients were assigned into two groups (n = 13), as follows: placebo and PBM. Sampling was repeated 7 days after root canal treatment. Two independent samples T test was used for analyzing of the differences between preoperative and postoperative substance P levels in GCF (p = .05). The Pearson correlation analysis was used for determination of correlation among substance P levels and other variables. For placebo group, there is no significant difference between preoperative and postoperative total amounts of substance P level (p = 0.553). For PBM group, postoperative total amount of substance P level was significantly higher than those of preoperative level (p = 0.005). Within the limitation of the present study, PBM has immunomodulation effect linked to the modulation of the total amount of substance P in the gingival crevicular fluid. Thai Clinical Trials Registry: TCTR20161228002.

Effect of Low-level Laser Therapy on Postoperative Pain in Molars with Symptomatic Apical Periodontitis: A Randomized Placebo-controlled Clinical Trial.

INTRODUCTION: In this clinical trial, we evaluated the effect of low-level laser therapy (LLLT) on postoperative pain in mandibular molar teeth with symptomatic apical periodontitis. METHODS: Forty-two patients were included in the study according to the inclusion and exclusion criteria. Root canal treatment was conducted using reciprocating instruments. The patients were randomly distributed into 3 groups using a Web program as follows: control (no laser was applied), placebo (mock laser therapy), and LLLT. Postoperative pain levels on the 1st, 3rd, 5th, 7th, and 30th day and postoperative percussion pain levels on the visual analog scale were recorded. The chi-square, 1-way analysis of variance, and least significant difference post hoc tests were performed to analyze the data (P = .05). RESULTS: LLLT resulted in lower pain levels than those noted in the control and placebo groups on days 1 and 3 (P < .05). There were no significant differences among the placebo, LLLT, and control groups in terms of postoperative percussion pain levels (P < .05). CONCLUSIONS: LLLT can be beneficial in reducing postoperative pain in endodontics.

Effect of intracanal diode laser application and low-level laser therapy on CGRP change

Abstract: The aim of this study was to investigate the effect of a placebo, intracanal diode laser application, and low-level laser therapy (LLLT) on the change of the total amount of calcitonin gene-related peptide (CGRP) in the gingival crevicular fluid (GCF) (split-mouth study design). GCF sampling was performed on a contralateral tooth and experimental tooth (root canal-treated tooth) of thirty-nine patients. The patients were divided into three groups (n = 13), as follows: placebo (mock laser application), intracanal laser application, and LLLT. GCF sampling was repeated at the same sites (experimental and control teeth) one week after root canal treatment. The data were analyzed using the Pearson's correlation analysis and the independent-samples t-tests (p=0.05). In the placebo group, the total CGRP level changes in the GCF before and after treatment was significantly higher for experimental teeth than for control teeth (p<0.05). However, there was no significant difference between experimental and control teeth in the intracanal laser application and LLLT groups (p > 0.05). Intracanal laser application and low-level laser therapy have immunomodulation effects linked to the modulation of the total amount of CGRP in the GCF.