Hanan Balto

Attachment and morphological behavior of human periodontal ligament fibroblasts to mineral trioxide aggregate: a scanning electron microscope study.

The attachment and morphology of human periodontal ligament fibroblasts to mineral trioxide aggregate (MTA) was evaluated using a scanning electron microscope. The material was placed at an apical cavity of 30 single-rooted slices of extracted human teeth. The specimens were divided into two groups of 15 root slices each (freshly mixed and set state). For each experimental group, five root slices were used per observation period (4, 8, and 24 h). A set of two glass slides was used per observation period for the control group. The experiments were performed in tissue-culture cluster 96-well plates in which 1 ml of human periodontal ligament fibroblast cell suspension was placed over the MTA filling and the control glass slides. For the positive-control group, 0.5 ml of methyl methacrylate 2% (vol/vol) was added to the cell suspensions before being dispensed into the wells. Results showed the normal cell morphology in the negative controls. Few round cells with less smooth surfaces and many rough blebs were seen in the positive control, and most of these cells did not show any attachment to the substratum. Similar observations were seen with the freshly prepared-MTA group. In the set-MTA group, cells were round and flattened, displayed smooth surfaces, and appeared to be tightly attached to MTA. It was concluded that the quality and quantity of cell attachment to the retrofilling material could be used as a criterion to evaluate materials toxicity. This research (FN#1077) is registered with the College of Dentistry research center, King Saud University, Riyadh, Saudi Arabia. The author thanks the administration of the King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia, and in particular Dr. M. N. Al-Ahdal for providing the use of the Molecular Virology and Infectious Disease Laboratory, Mr. Yunus Siddiqui for his support, and Dr. Saad AL-Nazhan for his assistance in preparing the manuscript.

AN ASSESSMENT OF MICROBIAL CORONAL LEAKAGE OF TEMPORARY FILLING MATERIALS IN ENDODONTICALLY TREATED TEETH

This in vitro study evaluated the microbial leakage of Cavit, IRM, and Dyract when used as temporary filling materials after root canal treatment. The degree of coronal leakage was assessed by using a microbiological marker consisting of Streptococcus faecalis and Candida albicans. For each of the two organisms, a set of 15 maxillary premolars were prepared chemomechanically and obturated with thermoplasticized gutta-percha. A 3.5-mm thick layer of one of the three temporary filling materials was inserted in the access cavities of the teeth from each group (each group was compromised of five teeth). The control teeth (four positive and four negative) lacked any filling material over the gutta-percha, whereas the orifice and the apical foramen of the negative control were completely sealed with nail polish. Each tooth was placed in a well of a 24-well tissue culture plate and embedded in trypticase soy broth and 0.5% Bactoagar. An organism suspension was inoculated in the access cavity, and microbial penetration was detected as an increase in turbidity of the broth. At the end of 30 days, the results showed that all positive control teeth leaked within 1 week, whereas those that served as negative control remained uncontaminated throughout the test period. With both organisms, IRM started to leak after 10 days, whereas Cavit and Dyract leaked after 2 weeks.

Antibacterial Efficacy of Octenisept, Alexidine, Chlorhexidine, and Sodium Hypochlorite against Enterococcus faecalis Biofilms

Introduction The purpose of this study was to evaluate the antibacterial effectiveness of Octenisept (OCT; Schülke & Mayr GmBH, Norderstedt, Germany), 1% alexidine (ALX) (Santa Cruz Biotechnology, Inc, Santa Cruz, CA), and 2% chlorhexidine (CHX) against Enterococcus faecalis biofilm using confocal laser scanning microscopy. Methods Root dentin discs were prepared from extracted human teeth, sterilized, and inoculated with E. faecalis strain (ATCC 29212) to establish 3‐week‐old biofilm model. Infected dentin discs were exposed to OCT (n = 20), 1% ALX (n = 20), and 2% CHX (n = 20) for 10 minutes. Dentin discs (n = 15) exposed to 5.25% sodium hypochlorite (NaOCl) were used as a positive control, whereas specimens exposed to saline (n = 15) were used as a negative control. After exposure, the dentin discs were stained with fluorescent LIVE/DEAD BacLight dye (Invitrogen Molecular Probes, Eugene, OR) and analyzed with confocal laser scanning microscopy to determine the proportion of dead cells in the biofilm. Statistical analysis was performed using the Kruskal‐Wallis and Mann‐Whitney U tests (P < .05). Results The highest proportion of dead cells was found in the 5.25% NaOCl group (94.14%; range, 92.30%–98.20%) compared with the experimental groups (P < .05). A significantly greater proportion of dead cells was found in the OCT group (74.14%; range, 70.03%–78.96%) compared with the 1% ALX and 2% CHX groups (P < .05). The proportion of dead cells was 43.89% (range, 24.86%–55.63%) and 42.78% (range, 25.45%–55.06%) in the 1% ALX and 2% CHX groups, respectively, with no statistical significant difference between the 2 groups (P > .05). Conclusions NaOCl had significantly greater antimicrobial activity against E. faecalis biofilms compared with OCT, CHX, and ALX. OCT was more effective than CHX and ALX. HighlightsSolutions were compared for their antibiofilm effect against Enterococcus faecalis biofilm.5.25% sodium hypochlorite was significantly more effective than all other solutions.1% alexidine and 2% chlorhexidine had low antibiofilm activity.Octenisept was more effective than either chlorhexidine or alexidine.

Combined effect of a mixture of tetracycline, acid, and detergent, and Nisin against Enterococcus faecalis and Actinomyces viscosus biofilms

Objectives: To evaluate the combined effect of a mixture of tetracycline, acid, and detergent (MTAD) and Nisin against Enterococcus faecalis (E. faecalis) and Actinomyces viscosus (A. viscosus) biofilms. Methods: This study was conducted between June and December 2013 in collaboration with Dental Caries Research Chair, College of Dentistry, King Saud University, Riyadh, Saudi Arabia. Single-species biofilms (n=9/species/observation period) were generated on membrane filter discs and subjected to 5, 10, or 15 minute incubation with MTADN (MTAD with 3% Nisin), 5.25% sodium hypochlorite (NaOCl), or normal saline. The colony forming units were counted using the Dark field colony counter. Results: A 100% bactericidal effect of 5.25% NaOCl was noted during the 3 observation periods; a significant reduction (p=0.000) in mean survival rates of E. faecalis (77.3+13.6) and A. viscosus (39.6+12.6) was noted after 5 minutes exposure to MTADN compared with normal saline (78000000+5291503) declining to almost no growth after 10 and 15 minutes. The survival rates of the E. faecalis and A. viscosus biofilm were no different after treatment with MTADN and 5.25% NaOCl at the 3 observation periods (p=1.000). Conclusion: A combination of MTAD and Nisin was as effective as NaOCl against E. faecalis and A. viscosus biofilms.

Effectiveness of Salvadora persica extracts against common oral pathogens

Objective The purpose of this study was to evaluate the antibacterial activity of ethanol and hexane extracts of Salvadora persica against common oral pathogens. Materials and methods Well diffusion, Minimum Inhibition Concentration (MIC), Minimum Bactericidal Concentration (MBC), and Broth microdilution tests were used to determine the optimum antimicrobial concentrations of S. persica extracts against Streptococcus mutans (S. mutans), Streptococcus sanguis (S. sanguis), and Streptococcus salivarius (S. salivarius) over 1, 3, 6, 12, and 24 h. Chlorhexidine (CHX) 0.2% was used as a positive control. Results The findings showed that the microbial activity of both extracts was concentration-dependent. Ethanol extract of S. persica at 25, 50, and 100 mg/ml had more growth inhibitory effect against all isolates compared to hexane extract. In addition, ethanol extract at 8 mg/ml (MBC value) was able to eradicate the growth of all isolates. S. sanguis and S. salivarius were very sensitive to hexane extract and required 4 mg/ml (MBC value) for their eradication while S. mutans was the most resistant (MBC = 8 mg/ml).The statistical findings of CFU counts showed no significant difference (p = 1.000) in antibacterial effectiveness between the two extracts against all isolates. A significant decline overtime in CFU counts was noted, except at 12 h and 24 h where no significant difference (p = 0.793) was observed and was comparable to CHX. Conclusion Ethanol and hexane extracts of S. persica were found to exhibit maximum antimicrobial activity against S. mutans, S. sanguis and S. salivarius at high concentrations.

Single Nucleotide Polymorphism (SNPs) in the Genes Associated with Tooth Agenesis

Objectives: The main focus of this review article was to collate up to date knowledge with regard to significance of single nucleotide polymorphisms (SNPs) in various genes associated with tooth agenesis. Failure to develop complete set of teeth also called tooth agenesis is a common developmental abnormality manifested mainly as an isolated condition. This anomaly is also associated with many developmental syndromes. Methods: We reviewed the evidence from the literature with regard to SNPs in many genes associated with this developmental anomaly. The information contained in this review deals only with non-syndromic form of tooth agenesis. This condition generally affects third molars or one or few other permanent teeth, however, in some cases its severity is relatively prevalent. Results and Conclusions: Mutations in genes such as Msh homeobox 1 (MSX1), Paired box gene 9 (PAX9), Axis inhibitor protein 2 (AXIN2) and Ectodysplasin A (EDA) have been identified that are associated with the familial form of the disease. It has been shown that the phenotypes associated with these mutations indicate the involvement of more complex mechanisms. Clinical Significance: Evidence collected so far has immense clinical significance to clinical dentists in providing comprehensive guide outlining the role of these gene mutations (SNPs) in various genes and also how the patients affected with this condition will be clinically diagnosed and managed in future.

Obturation Techniques Allow Microbial Leakage Unless Protected

PURPOSE To evaluate the quality of the apical 5-mm seal produced by different filling techniques using a bacterial leakage model. MATERIALS AND METHODS Sixty-five extracted single-rooted human teeth were decoronated, prepared, and instrumented. Roots were randomly divided into three experimental groups (15 roots each) and control groups (10 roots each). The apical 5 mm was filled with cold lateral condensation (CLC) technique, continuous wave of condensation (CWC), or injectable thermoplasticized gutta-percha (Obtura II) using AH26 Plus as a sealer. Positive controls were filled with gutta-percha without sealer, whereas negative controls were filled with a CLC technique and covered completely with two layers of nail varnish, including the orifice. A dual-chamber leakage model using Enterococcus faecalis as a microbial marker was used for leakage evaluation. Bacterial penetration was monitored over a 60-day period, and leakage was recorded when turbidity was observed in the lower chamber. RESULTS All positive controls exhibited turbidity in the lower chamber within 24 hours. All negative controls demonstrated no bacterial leakage for the entire 60-day observation period. The estimated mean day for leakage was 32 for CLC, 35 for CWC, and 30 days for Obtura II. Wilcoxon test showed no statistically significant difference (p = 0.98) in the survival time between the experimental groups. CONCLUSION The three filling techniques produced similar resistance to bacterial leakage when used to fill the apical 5-mm segment of the canal while leaving the rest of the canal unfilled.

The efficacy of Salvadora persica extracts in preserving the viability of human foreskin fibroblasts.

Objective To evaluate the efficacy of Salvadora persica hexane and ethanol extracts in preserving the viability of human foreskin fibroblasts. Materials and methods Normal human foreskin cells were cultivated in Dulbecco modified Minimum Essential Medium (D-MEM) supplemented with 10% fetal bovine serum and 2 mM of l-glutamine. Cell pellets were suspended in the following test solutions: (1) Hank’s Balanced Salt Solution (HBSS); (2) homogenized milk; (3) hexane extract of S. persica; or (4) ethanol extract of S. persica. D-MEM with no serum was used as a positive control. For each condition, cell count was adjusted to 8 × 105 cells/ml, and the cells were incubated in the solutions for either 30, 60, or 120 min. Subsequently, the nonviable cells were separated from the viable cells using the trypan blue dye stain. The ratio of viable to nonviable cells was recorded using a cell counter. Statistical analysis of the data was accomplished by one-way analysis of variance using SPSS Version 16. The level of significance was 5% (p < .05). Results We did not detect a significant difference when comparing the percentage of viable cells in test solutions at the three incubation periods (30 min, p = 0.478; 60 min, p = 0.606; 120 min, p = 0.091). Homogenized milk preserved the viability of foreskin fibroblasts better than all other tested solutions. Incubation of cells in S. persica hexane and ethanol extracts resulted in a similar percentage of viable cells to incubation of cells in HBSS for each incubation period. Conclusions S. persica hexane and ethanol extracts should be considered an alternative storage medium to HBSS.

Comparative analysis of prevalence of apical periodontitis in smokers and non-smokers using cone-beam computed tomography

Objective The aim of this study was to compare the prevalence and size of periapical lesions among smokers and non-smokers using cone-beam computed tomography (CBCT). Materials and methods Retrievable CBCT datasets for 46 male patients ≥18 years during a consecutive period from 2008 to 2016 were examined. The medical, smoking history and other clinical findings (signs of previous dental trauma; Decayed Missing Filled Teeth (DMFT) scores; the percentage of root filled teeth; and oral hygiene status) were obtained. Periapical status of all included teeth was assessed by CBCT images. Statistical analysis was conducted using t-test, Pearson correlation and multiple regression. Results The prevalence of apical periodontitis was 13.93% in smokers and 14.26% in non-smokers with no significant difference (p = 0.936). The mean of the average size of lesions between the two groups were almost comparable, 3.50 mm in smokers and 2.89 mm in non-smokers (p = 0.567). Pearson correlation and multiple regression analysis showed that the percentage of lesion present and the average lesion size were not correlated to any independent variable. Conclusions While smoking is considered a risk factor for marginal periodontitis, there was no difference between smokers and non-smokers in terms of apical periodontitis.

The synergistic effect of ultrasonic activation and irrigation on Enterococcus faecalis biofilm

Aim: The aim of this investigation was to compare the efficacy of passive ultrasonic irrigation (PUI) with either 2.5% sodium hypochlorite (NaOCl) or saline, with that of conventional syringe irrigation on intraradicular Enterococcus faecalis biofilm. Materials and Methods: Biofilms of E. faecalis were established over 21 days in 80 single roots that had undergone biomechanical preparation followed by gamma radiation. Biofilms were treated for 1 min with 2.5% NaOCl/PUI (Group 1), 2.5% NaOCl (Group 2), sterile saline/PUI (Group 3), and sterile saline (Group 4). The positive control (n = 4) was used to confirm the presence of biofilm before various treatments. Additional four samples that served as a negative control were used to confirm the sterility of the samples. Biofilm eradication was evaluated by Colony Forming Unit (CFU) quantification and scanning electron microscopy (SEM). Results: The median of CFUs of S1 was significantly higher than that of S2 in all experimental groups. SEM examination showed a significant difference between the positive control and the experimental groups (P < 0.001), with the highest score of biofilm in the positive control group followed by Group 4 and both groups were not statistically significant from each other (P = 0.067). Following various treatments, the highest scores of biofilm were observed in the coronal third and the least were in the apical third. Conclusions: PUI did not increase the effectiveness of NaOCl irrigation on biofilm removal, however, PUI enhanced biofilm disturbance when used with saline. The least mean score of remaining biofilm was in the apical third of all treatment groups compared to other thirds.