Colloidal chitosan-silver nanoparticles-fluoride nanocomposite as an antibacterial mouthwash against salivary Streptococcus mutans in orthodontic patients (a randomized clinical trial).

OBJECTIVES: This study aimed to synthesize and characterize colloidal chitosan-silver nanoparticles-fluoride nanocomposite (CCAgNPF) and evaluate its efficacy compared to chlorhexidine on salivary Streptococcus mutans in orthodontic patients. MATERIALS AND METHODS: AgNPs stabilized with chitosan were synthesized by chemical reduction of AgNO3. The nanoparticles were characterized with SEM, FTIR, DLS and ICP-OES. The MIC and MBC against S. mutans and IC50 concentration of CCAgNPF were obtained for antibacterial and cytotoxicity evaluations, respectively. For the clinical study, a total of 45 orthodontic patients were divided into three groups of 15 and used the following mouthwashes twice a day for 1 month: CCAgNPF, chlorhexidine 0.2% and the combination of these mouthwashes. The colony count of salivary S. mutans was evaluated before and after using the mouthwashes. The data were analyzed using One-way ANOVA and Tukey's test. RESULTS: Stabilized AgNPs were spherical with a diameter of 25.3 ± 3.3 nm. The MIC, MBC and IC50 of CCAgNPF were 4.42, 8.85 and 18.89 µg/ml. All mouthwashes reduced the salivary S. mutans of the orthodontic patients, however, no significant difference was found between the efficacy of CCAgNPF and chlorhexidine (P-value > 0.05). The best results were achieved by the combination of CCAgNPF and chlorhexidine mouthwashes (P-value < 0.05). CONCLUSION: The CCAgNPF and its combination with chlorhexidine present potent bactericidal, biocompatible and effective anti-carious mouthwashes for orthodontic patients. CLINICAL RELEVANCE: This study proved CCAgNPF as an antibacterial mouthwash with lower cytotoxicity and side effects for patients undergoing orthodontic treatments to maintain oral hygiene and reduce salivary S. mutans.

Comparative antibacterial effects of ginger and marjoram extract versus conventional irrigants on mature Enterococcus faecalis biofilms: An in vitro study.

Background: This study evaluated antibacterial effects of Ginger and Marjoram extract compared with Routine Intracanal Irrigants on Mature Enterococcus faecalis Biofilms. Material and Methods: Sixty-six extracted human teeth, were randomly assigned to four groups 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), chloroform extract of marjoram (Origanum majorana), and oil extract of ginger (Zingiber officinale), and two positive and negative control groups (n=11). Samples were contaminated with E. faecalis, except the negative control group. Then the root canals were irrigated with solutions above, after which dental debris was collected from each tooth separately, followed by culturing on plates containing BHI agar. The bacterial counts were finally determined with a colony counting machine. Results: No bacterial growth was detected in the NaOCl, CHX, and negative control groups. However, some bacterial growth was observed in the ginger and marjoram groups. All four solutions successfully eliminated E. faecalis biofilms compared to the positive control group. Significant difference in the median bacterial growth between the ginger and marjoram groups and the positive control group (P<0.001) has been shown. There was no significant difference in median bacterial growth between the ginger and marjoram groups (P=0.94). Conclusions: Chloroform extract of marjoram and oil extract of ginger were effective in eliminating 6-week-old biofilms of E. faecalis in vitro; however, their effect was not as favorable as CHX and NaOCl. These herbal extracts yielded promising results in the present study; therefore, they can be used as intracanal irrigants instead of chemical agents. Key words:Biofilm, Chlorhexidine, E. faecalis, Ginger, Marjoram, Sodium hypochlorite.

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.

The comparison of calcium hydroxide, curcumin, and Aloe vera antibacterial effects on 6-week-old Enterococcus faecalis biofilm as an intracanal medicament: An in vitro study.

Background: This study aimed to compare the antibacterial effects of calcium hydroxide, curcumin, and Aloe vera as an intracanal medicament on 6-week-old Enterococcus faecalis biofilm. Materials and Methods: In this in vitro study, the solution containing E. faecalis ATCC® 29212™ was inserted into the canals of 72 single-rooted teeth to produce biofilm. The samples were divided into four groups, and the antibacterial agent as an intracanal drug was used for 1 week. Calcium hydroxide, curcumin, and A. vera were used as intracanal medicaments in three groups, respectively, and the fourth group was irrigated with normal saline. The collected debris was cultured by spread plate method for the bacterial count by colony count machine, and the number of bacteria in each sample per ml was reported in colony-forming unit per ml (CFU/ml). The data were analyzed using SPSS software. KruskalWallis and MannWhitney U-tests were used for comparison of CFU/ml between the study groups. P <0.05 was considered significant. Results: The mean CFU/ml in the groups of calcium hydroxide, curcumin, and A. vera were 749.44, 630.55, and 1529.16, respectively. Compared with the control group, curcumin, calcium hydroxide, and A. vera showed 99.5%, 99.41%, and 98.79% antimicrobial effects, respectively. All three groups were significantly effective than the control group (P = 0.023, P = 0.023, and P = 0.024, respectively) but were not significantly different from each other (P = 0.057). Conclusion: All three groups showed significant antibacterial activity compared to the control group, curcumin had the most significant effect, followed by calcium hydroxide and A. vera. Therefore, herbal materials can be considered safe alternatives to synthetic medicaments for intracanal usage.

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.

Effect of incorporation of triphala into AH26 sealer on its cytotoxicity at different intervals.

Background. One of the essential properties of sealers used during endodontic treatment is their biocompatibility. Different materials are added to these sealers to improve their properties, including antibacterial activity. In recent years, there has been an increase in interest in the use of herbal medicines. This study aimed to evaluate the effect of incorporating triphala into AH26 sealer on its cytotoxicity on gingival fibroblasts at different intervals after mixing. Methods. In the present in vitro study, the cytotoxicity of AH26 sealer was evaluated once in its pure form and once after mixing it with triphala at 24-, 48-, and 72-hour, and 7-day intervals after mixing using the standard MTT assay protocol on gingival fibroblasts. Results. Two-way ANOVA was used to evaluate the effect of groups on the mean changes in cytotoxicity at different time intervals at a significance level of P<0.05. The results showed that the incorporation of triphala into the AH26 sealer did not increase or decrease its cytotoxicity (P=0.909). Besides, there was a decrease in cytotoxicity in both study groups. However, there was a relative increase in the sealers' cytotoxicity in both groups in the first 72 hours (P<0.0001). Conclusion. Considering the well-established antibacterial properties of triphala in our previous study, the present study's results showed that the incorporation of triphala into the AH26 sealer did not increase the cytotoxicity of the sealer. Therefore, it can be incorporated into the AH26 sealer to improve the other properties of the sealer, including its antibacterial activity.

Investigation of the optimal design of orthodontic mini-implants based on the primary stability: A finite element analysis.

Background. The design of an orthodontic mini-implant is a significant factor in determining its primary stability and its clinical success. The aim of this study was to measure the relative effect of mini-implant design factors on primary stability of orthodontic mini-implants. Methods. Thirty-two 3-dimensional assemblies of mini-implant models with their surrounding bone were generated using finite element analysis software. The maximum displacement of each mini-implant model was measured as they were loaded with a 2-N horizontal force. Employing Taguchi's design of experiments as a statistical method, the contribution of each design factor to primary stability was calculated. As a result of the great effect of the upper diameter and length, to better detect the impact of the remaining design factors, another set of 25 models with a fixed amount of length and diameter was generated and evaluated. Results. The diameter and length showed a great impact on the primary stability in the first set of experiments (P<0.05). According to the second set of experiments, increased taper angle in the threaded and non-threaded area decreased the primary stability. There was also an optimum amount of 2.5 mm for threaded taper length beyond which the primary stability decreased. Conclusion. It is advisable to increase the diameter and length if primary stability is at risk. In the second place, a minimum amount of taper angle, both in the threaded and non-threaded area with an approximate proportion of 20% of threaded taper length to MI length, would be desirable for MIs with a moderate size.

Esthetic preferences of laypersons of different cultures and races with regard to smile attractiveness.

BACKGROUND: Culture and ethnicity are among the factors affecting esthetic judgment of individuals. AIMS: This study aimed to assess the acceptability threshold of variations in four components of an esthetic smile namely vertical lip thickness, dental midline deviation, buccal corridor, and the golden ratio in maxillary lateral incisors display among laypersons of different races and cultures. SUBJECTS AND METHODS: Raters (n = 35 in each city) among laypersons of nine cities namely Istanbul, Isfahan, Tabriz, Tehran, Doha, Rome, Sydney, Chicago, and Yazd, were given a photo album containing 27 random images of an attractive female smile, digitally altered with regard to the four smile components. They scored each picture from 0 to 100 in terms of smile attractiveness. STATISTICAL ANALYSIS: Data were analyzed using SPSS 13 and the acceptability threshold for each component was calculated in each city using the Spearman and Wilcoxon tests. P< 0.05 was considered statistically significant. RESULTS: No significant differences were noted with regard to the increased vertical lip thickness, and an acceptability threshold could not be determined for it. The acceptability thresholds for midline deviations, buccal corridor, and the golden ratio were different among different cities. One-millimeter increase in the displayed width of maxillary lateral incisors was more desirable than the golden ratio standard width. CONCLUSION: Culture and race may significantly affect the esthetic preference of individuals with regard to smile attractiveness.

Sealing efficacy of mineral trioxide aggregate with and without nanosilver for root end filling: An in vitro bacterial leakage study.

BACKGROUND: Various materials have been added to mineral trioxide aggregate to enhance its properties. This study was aimed to compare the sealing efficacy of MTA with and without nanosilver using bacterial leakage approach. MATERIAL AND METHODS: Seventy canine teeth were prepared and obturated. Then, after apical resection, the root-end cavities were prepared by ultrasonic retrotips. Teeth were randomly divided into 4 groups containing two experimental groups (n=30) and two negative and positive controls (n=5). In group 1 and 2, root-end cavities were respectively filled with MTA and MTA with nanosilver (by 1% weight). Leakage assessment was carried out by bacterial leakage apparatus with Enterococcus faecalis species. Leakage comparison between experimental groups was done using Mann-Whitney test by Spss 16 software at significancy level of 0.05. RESULTS: The median bacterial leakages for MTA and MTA with nanosilver were 19 and 2, respectively. The mean bacterial leakages for MTA and MTA with nanosilver were 30.06±28.67 and 9.66±14.25, respectively. Mann-Whitney test indicated that there was a significant difference in bacterial leakage day between two experimental groups (P=0.002). CONCLUSIONS: Based on the findings of this in-vitro bacterial leakage study, adding nanosilver to MTA decreased its sealing ability. Key words:Root canal therapy, root canal obturation, root canal filling materials, nanosilver, MTA.

Esthetic perception of smile components by orthodontists, general dentists, dental students, artists, and laypersons.

AIM: In the present study, we sought to assess the esthetic perception and level of acceptability of variations in smile components, including dental midline, buccal corridor, vertical lip thickness, and the golden ratio, by orthodontists, general dentists, dental students, artists, and laypersons. METHODS: An attractive female smile was digitally manipulated with regard to four smile components: dental midline, buccal corridor, vertical lip thickness, and the golden ratio. The manipulated photographs (n=27) were randomly arranged in a photo album and scored by five groups of raters (n=50 in each group) from zero to 100 using a horizontal visual analog scale. The acceptability threshold of each component by the five groups was calculated using the Spearman and Wilcoxon tests. RESULTS: Orthodontists and laypersons had the same perception of midline deviations, with an acceptability threshold lower than that of artists and general dentists. Only orthodontists perceived variations of buccal corridor (by 20%). Changes in vertical lip thickness were not perceived by any group. Orthodontists, general dentists, and laypersons had similar perceptions of variations in the golden ratio. Dental students and artists did not perceive variations in this component. CONCLUSION: Professional dental training can affect the esthetic judgement of smiles in individuals.

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.

An in vitro comparison of the antibacterial efficacy of triphala with different concentrations of sodium hypochlorite.

INTRODUCTION: The antimicrobial efficacy of root canal irrigant plays an important role in increasing the success of root canal treatment (RCT). The aim of the present experimental study was to compare the antimicrobial activity of Triphala (a plant-derived solution) with 0.5, 1, 2.5 and 5% concentrations of sodium hypochlorite (NaOCl), against Enterococcus faecalis (E. faecalis). METHODS AND MATERIALS: Two hundred plates of cultured E. faecalis, were divided into 5 experimental groups (n=38) and two positive and negative control groups. The antimicrobial activity of the test solutions was determined by measuring the zone of inhibition in the culture media. The mean diameter of inhibited zones between the study groups was compared using the Kruskal-Wallis test and the Mann-Whitney U test was used for the two-by-two comparison of the groups with the level of significance set at 0.05. RESULTS: The Kruskal-Wallis test showed significant differences between the study groups (P<0.05). According to the Mann-Whitney U test the mean diameter of inhibition zones in Triphala group was significantly higher compared to 0.5 and 1% NaOCl (P<0.05). CONCLUSION: In this study, Triphala exhibited better antimicrobial activity against E. faecalis compared to 0.5 and 1% NaOCl (P<0.05).

An in vitro comparison of coronal microleakage of three orifice barriers filling materials.

INTRODUCTION: A coronal barrier in root-filled teeth is one of the most effective methods for prevention of coronal microleakage. The aim of this study was to compare coronal microleakage of three materials [light-cured glass-ionomer (GI), mineral trioxide aggregate (MTA), and composite resin] as coronal barriers. MATERIALS AND METHODS: A total of 188 intact maxillary incisors were used. After instrumentation, all the canals were obturated with gutta-percha and lateral condensation technique using AH26 sealer. Then, the teeth were sectioned just apical to the cemento-enamel junction. The roots were randomly assigned to three experimental groups (n=56) and two negative and positive control groups (n=20). After placing the orifice barrier, the samples were immersed in 2% methylene blue solution for 2 weeks at 37°C. Then the teeth were longitudinally sectioned mesiodistally and dye penetration was measured under a stereomicroscope at ×10 magnification. Data were analyzed with one-way ANOVA and a post-hoc Tukey test. RESULTS: The positive control group leaked significantly more than all the experimental groups (P=0.001). MTA exhibited less leakage than composite and GI (P=0.002) but no significant differences were found between GI and composite groups. CONCLUSION: Immediate placement of a suitable intra-orifice barrier like MTA, before final restoration, may help minimize recontamination of the remaining apical gutta-percha.

Nonsurgical endodontic retreatment of maxillary second molar with two palatal root canals: a case report.

Successful endodontic treatment requires thorough knowledge regarding each root canal system of any tooth and probability of extra canals should be considered. Second maxillary molar with two palatal root canals is not frequent and its incidence reported in literatures is about 0.4-2%. The present case report describes non-surgical retreatment of maxillary second mo-lar with two palatal root canals. Radiographic interpretation is difficult in this region; so, very careful examination of pulpal space and using supportive devices such as loupe and operating microscope is recommended to discover any unusual anat-omic features like extra canals.

Comparison of the sealing ability of mineral trioxide aggregate and Portland cement used as root-end filling materials.

Inadequate apical seal is the major cause of surgical endodontic failure. The root-end filling material used should prevent egress of potential contaminants into periapical tissue. The purpose of this study was to compare the sealing ability of four root-end filling materials: white mineral trioxide aggregate (MTA), gray MTA, white Portland cement (PC) and gray PC by dye leakage test. Ninety-six human single-rooted teeth were instrumented, and obturated with gutta-percha. After resecting the apex, an apical cavity was prepared. The teeth were randomly divided into four experimental groups (A: white MTA, B: gray MTA, C: white PC and D: gray PC; n = 20) and two control groups (positive and negative control groups; n = 8). Root-end cavities in the experimental groups were filled with the experimental materials. The teeth were exposed to Indian ink for 72 hours. The extent of dye penetration was measured with a stereomicroscope at 16× magnification. The negative controls showed no dye penetration and dye penetration was seen in the entire root-end cavity of positive controls. However, there was no statistically significant difference among the four experimental groups (P > 0.05). All retrograde filling materials tested in this study showed the same microleakage in vitro. Given the low cost and apparently similar sealing ability of PC, PC could be considered as a substitute for MTA as a root-end filling material.

Biological apexogenesis of undeveloped tooth in a patient with spondyloepiphyseal dysplasia: a case report.

This case report describes treatment of a necrotic immature permanent mandibular first molar with pulpal necrosis in 9-year old female with spondyloepiphyseal dysplasia. The coronal half of the root canal was debrided with a file #30 to remove necrotic tissue, and irrigated with chlorhexidine 0.12%. Bleeding was evoked to form an intracanal blood clot; the wound was then dressed with calcium hydroxide medication and provisionally restored with GIC. This was repeated at intervals of 1, 3 and 6 months. After six months, radiographic evidence revealed thickening of dentinal walls and apical closure. The progressive increase in dentinal wall thickness and apical development suggests that desirable biologic responses can occur with this form of treatment for the necrotic open apex of immature permanent teeth.