Publications by authors named "Emad Alshwaimi"

32 Publications

Preparation of a toothpaste containing theobromine and fluoridated bioactive glass and its effect on surface micro-hardness and roughness of enamel.

Dent Mater J 2021 Mar 19;40(2):393-398. Epub 2020 Nov 19.

Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University.

The aim was to synthesize a toothpaste and analyze its effect on surface micro-hardness and roughness of enamel. Basic paste was prepared by using basic ingredients. Theobromine (0.2 wt%) and laboratory synthesized fluoridated-bioactive glass (F-BG, 4 wt%) were added to it. Post-demineralization, 36 enamel blocks were divided into six groups that were brushed with their respective toothpaste+artificial saliva (AS): group 1 (control): basic paste; group 2: basic paste+theobromine; group 3: commercial theobromine toothpaste; group 4: commercial BG toothpaste; group 5: basic paste+F-BG; and group 6: basic paste+theobromine+F-BG. On micro-hardness analysis, group 6 performed best, followed by group 4. Surface roughness results showed the maximum decrease in roughness values for group 6, followed by group 5. Treatment with toothpaste composition containing theobromine+F-BG resulted in the enamel's increased micro-hardness and decreased surface roughness.
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http://dx.doi.org/10.4012/dmj.2020-078DOI Listing
March 2021

Efficacy of the Rotary Instrument XP-Endo Finisher in the Removal of Calcium Hydroxide Intracanal Medicament in Combination with Different Irrigation Techniques: A Microtomographic Study.

Materials (Basel) 2020 May 12;13(10). Epub 2020 May 12.

Endodontic Division, Restorative Dental Sciences Department, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia.

Objectives: This study aims to evaluate the efficacy of the rotary instrument XP-endo Finisher for the removal of Ca(OH) aided by different irrigation regimens.

Methods: Sixteen double-rooted upper premolar human teeth were selected for the study. Thirty-two canals were prepared using a ProTaper Next rotary system up to X3. Then, the canals were filled with Ca(OH). The volume of Ca(OH) inside the canals was measured by microcomputed tomography (micro-CT). After that, the teeth were randomly allocated into two experimental groups, i.e., A and B (n = 16 canals). In group A, Ca(OH) was removed using the master apical file (X3). In group B, Ca(OH) was removed using a XP-endo finisher. In half of both groups (n = 8), syringe irrigation (SI) was used, while passive ultrasonic irrigation (PUI) was used for the other half. After removal, the remaining volume of Ca(OH) was measured. All data were statistically analyzed using two-way ANOVA with Tukey's post hoc test.

Results: The percentages of remaining Ca(OH) in the apical thirds of all canals were significantly higher as compared with the middle and coronal thirds in all groups ( < 0.05). There was no significant difference between different files and techniques ( > 0.05).

Clinical Significance: This study presents a new method for the removal of Ca(OH) from root canals.
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http://dx.doi.org/10.3390/ma13102222DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7288082PMC
May 2020

Effect of Sterilization on Cyclic Fatigue Resistance of Proflexendo Endodontic Rotary Files.

Authors:
Emad O Alshwaimi

Saudi J Med Med Sci 2019 Sep-Dec;7(3):151-155. Epub 2019 Feb 8.

Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.

Background: Proflexendo file (Nexen, Houston, TX, USA) is a recently developed, novel nickel-titanium rotary file. However, several physical properties of the Proflexendo system remain to be investigated.

Objectives: The aim of this study was to determine the effect of sterilization on cyclic resistance of Proflexendo files.

Material And Methods: A total of 120 unused Proflexendo rotary files (40 each of file sizes 40/0.04, 30/0.04 and 20/0.06) were used in this study. Each set of files was subdivided into four groups of ten files. Group 1 did not undergo any sterilization (control), Group 2 underwent two rounds (2×) of sterilization, Group 3 five rounds (5×) and Group 4 ten rounds (10×). Cyclic fatigue resistance was tested using an artificial canal with a 5-mm radius curve.

Results: The nonsterilized size 30/0.04 files had the highest cycles to failure, followed by the nonsterilized size 40/0.04 and 20/0.06 files ( < 0.001). With increasing rounds of sterilization, cycles to failure reduced for sizes 40 (2×, 5× and 10×) and 30 (2×) files compared with nonsterilized sizes 40 ( < 0.05) and 30 files ( < 0.001), respectively.

Conclusion: Under the conditions of the current study, the results provide preliminary evidence that autoclave sterilization of Proflexendo rotary files reduced their cyclic fatigue resistance, except for size 20 (2× and 5×) and 30 (10×) files, in which resistance increased. Single use of this file is recommended to reduce the risk of separation.
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http://dx.doi.org/10.4103/sjmms.sjmms_123_17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6734735PMC
February 2019

Shaping Ability of HyFlex EDM and ProTaper Next Rotary Instruments in Curved Root Canals: A Micro-CT Study.

J Contemp Dent Pract 2019 Jun 1;20(6):680-685. Epub 2019 Jun 1.

Division of Endodontic, Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.

Aim: The aim of this study is to evaluate and compare the shaping ability of HyFlex™ EDM (HFEDM) and ProTaper Next (PTN) rotary instruments in curved root canals by using micro-computed tomography (micro-CT) imaging.

Materials And Methods: A total of 22 mandibular molar teeth having separate mesial canals with 20 to 30° curvatures were randomly divided into two groups and instrumented with HFEDM (OneFile) or PTN (X1 and X2). Pre- and post-instrumentation micro-CT scans were obtained. Mesiodistal canal transportation and centering ability were evaluated in four cross-sections (2, 4, 6, and 8 mm from apex). Changes in canal volume and surface area were measured for a 10-mm standardized area of interest. Kolmogorov-Smirnov and Shapiro-Wilk tests were used to assess the normality and homogeneity. Independent and paired t tests and one-way ANOVA were used to analyze data at the < 0.05 level.

Results: Compared to PTN, HFEDM showed significantly less mesiodistal canal transportation and improved centering ability in cross-section L6 ( < 0.05). The instruments showed similar increases in volume and surface area of the canals, with minor insignificant differences.

Conclusion: HFEDM and PTN files were safe to use in curved canals and showed similar shaping ability, while respecting the original anatomies. HFEDM OneFile performed better at the vicinity of the danger zone in terms of mesiodistal canal transportation and centering ability.
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June 2019

Evaluation of the fit of zirconia three-unit fixed partial dentures fabricated by different impression techniques.

J Investig Clin Dent 2019 Aug 18;10(3):e12413. Epub 2019 Apr 18.

Department of Research and Prosthodontics, Faculty of Dental Medicine, Lebanese University, Hadath, Lebanon.

Aim: The aim of the present study was to evaluate the marginal and internal fit of zirconium fixed partial denture using different impression techniques.

Methods: A Nissin Typodont model, including maxillary central incisor and canine with missing lateral incisor, was selected for the present study. Thirty zirconium frameworks were fabricated following three impression techniques (N = 10), conventional silicone impression (group C), scanned dental impression (group S), and Trios 3 (3Shape) intraoral scanner (group T). An extra-fine milling strategy was applied.

Results: Group T had the smallest discrepancy compared to groups C (P = 0.006) and S (P = 0.052) at the marginal level, whereas it was larger at the incisal tip. Discrepancies in group T were smaller than group C (P = 0.004) when measured at the axial walls, and smaller than group S (P = 0.045) when measured at the chamfer area for the central teeth only. Samples in group T showed a greater percentage of equally extended restorations (52.5%), while other groups were mainly underextended (group C: 63.7%, group S: 68.8%).

Conclusion: Better adaptation was achieved with the intraoral scanner group, except at the incisal tip. Conventional and scanned impressions revealed a greater percentage of underextended restorations.
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http://dx.doi.org/10.1111/jicd.12413DOI Listing
August 2019

Micro-computed tomography analysis of gap and void formation in different prefabricated fiber post cementation materials and techniques.

Saudi Dent J 2019 Apr 7;31(2):236-241. Epub 2019 Jan 7.

Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.

Objective: The study was built around the objective of determining the variances in the gap and void formation around cemented prefabricated fiber posts with two different cementation materials and techniques with micro-computed tomography (μCT).

Methods: Standardized acrylic resin roots (N = 40) with prefabricated fiber posts (RelyX™ Fiber Post 3D) were split into four sets (n = 10) based on many types of cementation materials and techniques. In the first group, resin cement (RelyX™ Unicem) was inserted to the canals via root canal tips. In the second group, the same cement was injected, and a microbrush was used to distribute the cement inside the canal. In the third group, dual polymerizing resin cement (MultiCore® Flow) was injected into the canals by using root canal tips. In the fourth group, the same cement was injected, and a microbrush was used to distribute the cement inside the canal. The gap and void formation in the cement and the root canals was evaluated with μCT. IBM SPSS Statistics was used to perform the statistical evaluation, then the Kolmogorov-Smirnov test of normality and Kruskal-Wallis H test to compare these variables with respect to the all groups significant difference (a = 0.05).

Results: The study outlined no difference of significance when evaluating the gap and void formation within the experimental groups (P > 0.05).

Conclusion: There was a certain amount of void and gap formation inside all of the tested specimens. However, no significant variances were found.
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http://dx.doi.org/10.1016/j.sdentj.2019.01.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6445436PMC
April 2019

Marginal and internal fit of CAD/CAM fiber post and cores.

Int J Comput Dent 2019;22(1):45-53

Aim: To evaluate the marginal adaptation and internal fit of milled fiber post and cores using different scanning methods.

Materials And Methods: Thirty typodont tooth models (Nissin) with pulp cavity were endodontically treated and prepared to receive 30 fabricated fiber post and cores. Three different methods of scanning were used (n = 10): an intraoral scanner (IOS) (Trios 3; 3Shape) to directly digitalize the post space (Group T) and a laboratory scanner to indirectly digitalize the resin pattern (Group RP) and the silicone impression (Group S) of the post space. All the specimens were examined using an optical microscope for the measurement of the vertical marginal discrepancy (VMD), and five in each group were scanned using microcomputed tomography (µCT) for the assessment of the VMD, the internal fit at the corner (IFC), post apex (PA), and at four horizontal cross-sections (CS1-4) inside the canal. All data were analyzed using mixed-design ANOVA, followed by pairwise testing to identify the differences (α = 0.05).

Results: Statistical analysis revealed that Group T was associated with the smallest cement space compared with Group RP (P = 0.001) and Group S (P < 0.001) for VMD using µCT or direct microscopy (OM) (P < 0.001). Similarly, the cement space for Group T was smaller than that of Group S (P = 0.039) when measured at the IFC (µCT), and smaller than Group RP (P = 0.025) when measured at CS1-4 (µCT), with CS1 larger than CS3 (P = 0.015). There was no significant difference at PA (P = 0.271).

Conclusion: Better adaptation was achieved with a complete digital workflow. Scanning the resin pattern or the silicone impression introduced more variables in the digital process or milling of a one-piece fiber post and core.
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October 2019

Association between Diabetes Mellitus and Periodontal Diseases: A Survey of the Opinions of Dental Professionals.

Med Princ Pract 2019 29;28(2):141-149. Epub 2018 Nov 29.

UWA Dental School, University of Western Australia, Nedlands, Washington, Australia,

Objective: This cross-sectional survey aimed to assess the knowledge of dentists and dental assistants practicing in Saudi Arabia regarding diabetes mellitus (DM) and periodontal diseases.

Subjects And Methods: We used a pretested, closed-ended, multiple-choice questionnaire covering 2 principal sections: the assessment of previous educational training and practice, and the knowledge and scientific background regarding DM and periodontal diseases. The responses were grouped using the Likert-type scale.

Results: The questionnaire showed a high reliability value of 0.805 as determined by a Cronbach's α. Out of 365 subjects who were initially interviewed, 239 subjects participated (response rate 65.5%): general dentists (45.6%) and dental hygienists and assistants (54.4%). Of the participating dentists, 70.4% were males; in contrast, 87.7% of dental assistants were female. Eighty-five percent of the participants strongly agreed that evidence supports the association between periodontal diseases and DM. Remarkably, dental assistants (78%) agreed more than dentists (68.5%) that diabetic patients with periodontal conditions would have worse glycemic control compared to diabetic patients with no periodontal diseases. Seventy-five percent of the respondents were confident about performing oral health screening for diabetic patients. Significantly more dental assistants showed their desire to expand their practice to include oral health screening (85%) and education compared to dentists (74%).

Conclusions: Both dentists and dental assistants in Saudi Arabia revealed a satisfactory knowledge level regarding the periodontal disease-diabetes interactions with no significant difference between the two groups. Further studies are recommended to assess the attitude of dental care providers while dealing with diabetic patients.
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http://dx.doi.org/10.1159/000495881DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6546030PMC
June 2020

Push-out bond strength of different types of mineral trioxide aggregate in root dentin.

Int J Health Sci (Qassim) 2018 Sep-Oct;12(5):66-69

Department Restorative Dental Sciences, Division of Endodontic, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.

Objective: The objective of this study was to measure the push-out bond strength of three types of mineral trioxide aggregate (MTA) materials in root dentin.

Methods: The study was carried out at the College of Dentistry, Imam Abdulrahman Bin Faisal University from March 2014 to January 2015. Thirty extracted maxillary central incisors were selected, instrumented, irrigated, and randomly assigned into three groups ( = 10): Group 1 - Ortho MTA; Group 2 - MTA Angelus; and Group 3 - ProRoot MTA. Materials were mixed following the manufacturers' recommendations and canals were filled. Teeth were stored in distilled water for 6 months. The push-out bond strength was evaluated using 2-mm thick coronal root sections. The data were analyzed with one-way ANOVA and Tukey-Kramer multiple comparison tests statistically significant at < 0.05.

Results: The mean bond strength values were 68.69 ± 29.63 MPa for Ortho MTA, 42.54 ± 32.78 MPa for MTA Angelus, and 72.75 ± 26.27 MPa for ProRoot MTA groups. There were no significant differences between the bond strengths of tested materials ( > 0.05).

Conclusion: Ortho MTA, MTA Angelus, and ProRoot MTA materials showed similar push-out bond strength values in root dentin.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6124834PMC
September 2018

Comparing ProFile Vortex to ProTaper Next for the efficacy of removal of root filling material: An micro-computed tomography study.

Authors:
Emad AlShwaimi

Saudi Dent J 2018 Jan 3;30(1):63-69. Epub 2017 Nov 3.

Endodontic Division, Restorative Dental Sciences Department, College of Dentistry, University of Dammam, Dammam, Saudi Arabia.

Aim: This study compared the efficacy of ProFile Vortex (PV) with that of ProTaper Next (PTN) for the removal of root canal filling material.

Materials And Methods: Twenty-six mesial canals of extracted mandibular first molars were instrumented, obturated with gutta-percha and sealant, and randomly allocated to a PTN (X3, X2, or X1) or PV group. The percentage of remaining material, amount of dentin removed, and extent of transportation were assessed using micro-computed tomography. The total time required for removal of material was calculated.

Results: Both systems were effective for material removal ( ≤ 0.001). Less time was required to remove material using PV (256.43 ± 108.95 s) than using PTN (333.31 ± 81.63 s;  ≤ 0.05). PV and PTN files removed approximately 84% and 78% of the filling material, respectively ( > .05). There was no significant canal transportation in either group. PV and PTN files removed 1.32 ± 0.48 mm and 1.63 ± 0.67 mm of the dentin, respectively ( = .18).

Conclusion: Our findings suggest that PV is as effective as PTN for removal of root canal filling material. Therefore, PV can be considered for use in endodontic retreatment, although more effective files or techniques are still required.
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http://dx.doi.org/10.1016/j.sdentj.2017.10.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6112351PMC
January 2018

Influence of culture change on the perception of fear and anxiety pathways in Endodontics: A pilot proof of concept study.

Aust Endod J 2019 Apr 16;45(1):20-25. Epub 2018 Jan 16.

School of Dentistry, Griffith University, Southport, Gold Coast, Queensland, Australia.

This study assessed the influence of cultural changes (known as acculturation) on pathways of fear and anxiety in Endodontics. A purposive sampling technique identified patients of Saudi Arabian descent living in Australia and Saudi Arabia. Only patients with root canal fillings (or treatment planned for endodontic treatment) were included. Patients with intellectual disabilities, surgical root therapy, and aged under 20 were excluded. Consenting patients attending the dental clinics of University of Griffith University, Australia and University of Dammam, Saudi Arabia completed the "My Endodontic Fear Questionnaire." Three hundred and twenty-four patients (21-75 years) were included, 90% of participants reported more than one pathway. Australian Saudi Arabians mainly utilised vicarious pathway (94.9%), whilst Saudi Arabians utilised the verbal threat (93.5%) and parental pathway (78.3%). This study highlights the possible role of acculturation on the perception of fear and anxiety in Endodontics; however, further research with other ethnic groups is essential to enhance our understanding.
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http://dx.doi.org/10.1111/aej.12253DOI Listing
April 2019

Cutting efficiency of different dental materials utilized in an air abrasion system.

Int J Health Sci (Qassim) 2017 Sep-Oct;11(4):23-27

Department of Restorative Dental Sciences, College of Dentistry, University of Dammam, Kingdom of Saudi Arabia.

Objectives: The aim of the present study was to test cutting efficiency of different materials against conventional alumina in an air abrasion system.

Materials And Methods: The powder samples were divided into three groups: Group 1 - alumina (control), Group 2 - 45S5 bioactive glass, and Group 3 - hydroxyapatite. 30 microscope glass slides of 0.5 mm thickness were used as an alternative of human enamel and were also divided randomly into these three groups. The time taken by the abrasive particles to cut a hole through the microscope glass slide was recorded with a stop watch. In addition, morphology of the particles was observed through scanning electron microscopy (SEM). A -test was used to compare the times taken to cut a hole through the microscope glass slides, and the level of significance was set at < 0.05.

Results: The mean time taken to cut a hole through the microscope glass slide was 2.96 s and 23.01s for Groups 1 and 2, respectively, whereas powder of Group 3 did not cut after 120 s. The differences between cutting times of Groups 1 and 2 were statistically significant ( < 0.05). The SEM micrographs revealed coarse angular shape for particles of Groups 1 and 2 but Group 3 particles were with round ends and presence of smaller particles was also observed in Groups 2 and 3.

Conclusion: The alumina particles demonstrated excellent cutting efficiency followed by 45S5 particles. The use of bioactive glass particles should be encouraged for cutting purposes whenever a shortage of time for practitioners is not a concern.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5654181PMC
November 2017

The Effect of Heating Time and Temperature on Epoxy Resin and Calcium Silicate-based Endodontic Sealers.

J Endod 2017 Dec 21;43(12):2112-2118. Epub 2017 Oct 21.

Department of Restorative Dental Sciences, College of Dentistry, University of Dammam, Dammam, Kingdom of Saudi Arabia.

Introduction: With the growing use of warm obturation techniques during endodontic treatment, more interest is directed toward sealers' compatibility with heat. This study aimed to evaluate the effect of heat application duration and temperature on epoxy resin- and calcium silicate-based sealers using chemical and thermogravimetric analyses.

Methods: Freshly mixed samples (n = 5/group) of each sealer were heated at 200°C or 250°C for 30 or 60 seconds. Additional 2 sets of samples were examined directly after mixing or after setting without heat exposure. Raman spectroscopy was used to identify changes in the chemical structure, and a 2-way analysis of variance was performed to compare values of measurable peaks that exhibited changes. Additionally, Thermogravimetric Analysis (TGA) was used to evaluate the effect of heat on mass change where sealers were heated to 250°C at a rate of 20°C/min (11-minute duration) or maintained at 37°C for 8 hours.

Results: No differences were detected among all the spectra of calcium silicate samples of different groups, while TGA revealed 15% and 18% weight loss upon heating at 250°C and 37°C, respectively. For the resin sealer, significant differences were detected when samples were heated for 60 seconds, involving bonds of benzene rings and aromatic amines in the uncured resin. TGA revealed minimal changes in the sealer mass (1.2% and 1.8%) on heating at 250°C and 37°C, respectively.

Conclusions: Heat application duration and temperature can affect the chemical structure of epoxy resin sealers. The consideration of endodontic sealer compatibility as well as the duration of heat application is essential when warm vertical obturation is used.
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http://dx.doi.org/10.1016/j.joen.2017.08.008DOI Listing
December 2017

Push-Out Bond Strength of Calcium Silicate-Based Materials.

Med Princ Pract 2017 9;26(4):396. Epub 2017 Jun 9.

Division of Endodontics, Restorative Dental Sciences Department, College of Dentistry, University of Dammam, Dammam, Saudi Arabia.

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http://dx.doi.org/10.1159/000477683DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5768131PMC
November 2017

Evaluation of root canal morphology of maxillary second premolars in a Saudi Arabian sub-population: An in vitro microcomputed tomography study.

Saudi Dent J 2016 Oct 17;28(4):162-168. Epub 2016 Oct 17.

Department of Restorative Dental Sciences, College of Dentistry, University of Dammam, Dammam, Saudi Arabia.

Aim: To investigate the root canal morphology of maxillary second premolars in a Saudi Arabian subpopulation using microcomputed tomography (micro-CT).

Methodology: Micro-CT analysis was performed on 100 maxillary second premolars. The anatomy of each tooth (number of roots, canals, orifices, and apical foramina, and the presence of apical deltas and accessory canals) was analyzed from reconstructed three-dimensional images.

Results: The most common morphology was a single root (67%), followed by two roots (30%), and three roots (3%). Regarding the canal morphology, most teeth (65%) contained two canals, followed by 30% with one canal, and 5% with three canals. One orifice was observed in 55% of teeth, and two orifices were detected in 45% of teeth. According to the Vertucci classification, the most common canal types were IV and V (both found in 23% of teeth), followed by type I (17%), type III (9%), type II (7%), and type VII (2%). Additional types that were inconsistent with the Vertucci classification were recorded in 19% of teeth.

Conclusion: The root canal morphology of maxillary second premolars in the Saudi Arabian subpopulation is complex and requires cautious evaluation prior to endodontic treatment.
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http://dx.doi.org/10.1016/j.sdentj.2016.08.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5110470PMC
October 2016

Push-Out Bond Strength and Surface Microhardness of Calcium Silicate-Based Biomaterials: An in vitro Study.

Med Princ Pract 2017 15;26(2):139-145. Epub 2016 Nov 15.

Division of Endodontics, Restorative Dental Sciences Department, College of Dentistry, University of Dammam, Dammam, Saudi Arabia.

Objective: This was an in vitro evaluation of push-out bond strength and surface microhardness of calcium silicate-based biomaterials in coronal and apical root dentin.

Materials And Methods: Ninety sections (2 mm thick) of coronal and apical root dentin were obtained from roots of 60 extracted teeth; the canals were enlarged to a standardized cavity diameter of 1.3 mm. Sections were randomly divided into 6 groups (n = 15 per group), and cavities were filled with Biodentine™, BioAggregate, or ProRoot mineral trioxide aggregate (MTA), according to the manufacturers' instructions. Push-out bond strength values were measured using a universal testing machine under a compressive load at a speed of 1 mm/min. Samples were analyzed under a light microscope to determine the nature of bond failure. Ten samples (2 mm thick) were prepared for all the materials, and Vickers microhardness was determined using a digital hardness tester. Data were analyzed using one-way analysis of variance and Tukey-Kramer multiple comparison tests at a significance level of p < 0.05.

Results: Biodentine (42.02; 39.35 MPa) and ProRoot MTA (21.86; 34.13 MPa) showed significantly higher bond strengths than BioAggregate (6.63; 10.09 MPa) in coronal and apical root dentin, respectively (p < 0.05). Biodentine also differed significantly from ProRoot MTA in coronal dentin. Bond failure was predominantly adhesive in Biodentine and ProRoot MTA, while BioAggregate showed predominantly mixed failure. ProRoot MTA (158.52 HV) showed significantly higher microhardness and BioAggregate (68.79 HV) showed the lowest hardness.

Conclusion: Biodentine and ProRoot MTA showed higher bond strength and microhardness compared to BioAggregate.
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http://dx.doi.org/10.1159/000453455DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5639710PMC
October 2017

A Micro-Computed Tomography Study of the Root Canal Morphology of Mandibular First Premolars in an Emirati Population.

Med Princ Pract 2017 3;26(2):118-124. Epub 2016 Nov 3.

Boston University Institute for Dental Research and Education, Dubai Health Care City, Dubai, UAE.

Objective: To investigate variations in the root canal morphology of mandibular first premolars in a population from the United Arab Emirates using micro-computed tomography (micro-CT) and conventional radiography.

Materials And Methods: Three-dimensional images of 50 extracted human mandibular first premolars were produced using a micro-CT scanner, and conventional radiography was also used to record the number of roots, the root canal system configuration, the presence of a C-shaped canal system and lateral canals, intercanal communications, and the number and location of apical foramina. The interpretations of micro-CT and conventional radiography were statistically analyzed using Fisher's exact test.

Results: Variable root canal configurations based on Vertucci's classification were observed in the teeth (i.e., types I, III, IV, V, and VII). The examined teeth exhibited the following 2 additional root canal configurations, which did not fit Vertucci's classification: type 1-2-3 and type 1-3. A C-shaped canal configuration was present in 14 (28%) cases, and lateral canals were present in 22 (44%) cases. Apical deltas were found in 25 (50%) cases, intercanal communications were seen in 6 (12%) cases, and apical loops were seen in 2 (4%) of the samples. Micro-CT and X-ray imaging identified 39 (78%) and 34 (68%) apical foramina, respectively. A single apical foramen was detected in 33 (66%) samples, and 2 or 3 apical foramina were detected in 14 (28 %) and 3 (6%) samples, respectively. In 18.5 (37%) samples the apical foramina were located centrally, and in 31 (62%) they were located laterally.

Conclusion: A complex morphology of the mandibular first premolars was observed with a high prevalence of multiple root canal systems.
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http://dx.doi.org/10.1159/000453039DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5588359PMC
October 2017

In Vitro Antimicrobial Effectiveness of Root Canal Sealers against Enterococcus faecalis: A Systematic Review.

J Endod 2016 Nov 9;42(11):1588-1597. Epub 2016 Sep 9.

Endodontic Division, Restorative Dental Sciences Department, College of Dentistry, University of Dammam, Dammam, Saudi Arabia.

Introduction: The purpose of this systematic review was to summarize the outcomes of in vitro studies of root canal sealers for their antimicrobial effectiveness against Enterococcus faecalis on the basis of direct contact test.

Methods: An exhaustive literature search was performed by using MEDLINE, Scopus, TRIP, and OpenThesis databases, followed by an extensive hand search of references of identified articles. Two independent reviewers evaluated the studies for eligibility against inclusion and exclusion criteria and performed data abstraction and risk of bias evaluations.

Results: A total of 31 articles were assessed for eligibility. Of these, 24 met the inclusion criteria and were included in the systematic review. A considerable heterogeneity was found in the methodologies of included studies. Therefore, it was not feasible to perform meta-analysis. Majority of the studies reported that different categories of freshly prepared sealers possessed some form of positive antimicrobial activity against E. faecalis for up to 24 hours. Antimicrobial efficacy was lost as the material set. Moderate evidence was found for no antimicrobial activity of aged (2-day to 7-day set) sealer samples across all categories.

Conclusions: The evidence indicated positive antimicrobial activity of freshly mixed sealers against E. faecalis. Antimicrobial efficacy was lost as the material set, with no bacterial growth inhibition by 2-day to 7-day set sealer samples. However, the studies included in this review presented medium to high risk of bias. This review identified the need for the development of standardized methods to evaluate antimicrobial activity of root canal sealers in in vitro studies.
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http://dx.doi.org/10.1016/j.joen.2016.08.001DOI Listing
November 2016

Pulpal Responses to Direct Capping with Betamethasone/Gentamicin Cream and Mineral Trioxide Aggregate: Histologic and Micro-Computed Tomography Assessments.

J Endod 2016 Jan 31;42(1):30-5. Epub 2015 Oct 31.

Biomedical Dental Sciences Department, College of Dentistry, University of Dammam, Dammam, Saudi Arabia.

Introduction: This clinical trial was conducted to evaluate the response of human dental pulp to direct capping with betamethasone/gentamicin (BG) cream and mineral trioxide aggregate (MTA). We hypothesized that the results of direct pulp capping with a topical BG combination would be similar to or better than those with MTA.

Methods: Thirty-six human first premolar teeth scheduled for orthodontic extraction were randomly divided into 4 groups: BG1 group (n = 9), BG cream with 2-week follow-up; BG2 group (n = 10), BG cream with 8-week follow-up; MTA1 group (n = 8), MTA with 2-week follow-up; and MTA2 group (n = 9), MTA with 8-week follow-up. Teeth were extracted and evaluated at respective time intervals. Micro-computed tomography scanning and histologic analyses were performed for all specimens. Pulp pathology (inflammation, pulp abscesses, and pulp necrosis) and reparative reaction (formation of dentin bridges) were recorded.

Results: Both BG cream and MTA resulted in significantly better pulpal responses at 8 weeks than at 2 weeks. Dentin bridge formation was significantly thicker in the MTA group at 8 weeks than in any other group (P < .05). Inflammation was of the acute type in all groups; no statistically significant differences in the distribution of inflammatory cells were found among the groups. Pulpal abscesses and/or necrosis were observed more often in teeth capped with BG than with MTA.

Conclusions: Direct pulp capping with both BG cream and MTA was associated with dentin bridge formation. MTA resulted in a significantly better pulpal response, with less inflammation and a thicker dentin bridge at 8 weeks.
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http://dx.doi.org/10.1016/j.joen.2015.09.016DOI Listing
January 2016

Micro-computed tomographic assessment of quality of obturation in the apical third with continuous wave vertical compaction and single match taper sized cone obturation techniques.

Scanning 2016 07 7;38(4):352-6. Epub 2015 Oct 7.

Department of Oral and Maxillofacial Sciences, College of Dentistry, Al-Farabi Colleges, Riyadh, Saudi Arabia.

The aim of the present micro-computed tomography (Micro-CT) analysis was to compare the quality of obturation in the apical third of the root with the warm vertical compaction (WVC) and single matching taper sized cone (SMTSC) techniques. Mesial roots of 16 freshly extracted mandibular first molar teeth (with a total of 32 canals) were used. Canals in each mesial root were shaped to a size F3 Protaper and were randomly assigned to either continuous wave vertical compaction or single match tapered size cone technique. Volume of voids and gaps in the obturated roots were measured using micro-CT scanning at 1, 3, and 5 mm from the apex of the root. There was no statistically significant difference in the volume of voids measured at 1 mm (p > 0.05), 3 mm (p > 0.05) and 5 mm (p > 0.05) filled with either WVC and SMTSC techniques. The quality of obturation in the apical third of the root with the WVC and SMTSC techniques is comparable. SCANNING 38:352-356, 2016. © 2015 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/sca.21277DOI Listing
July 2016

In vitro dentin tubule occlusion and remineralization competence of various toothpastes.

Arch Oral Biol 2015 Sep 6;60(9):1246-53. Epub 2015 Jun 6.

Department of Restorative Dental Sciences, College of Dentistry, University of Dammam, Kingdom of Saudi Arabia.

Objectives: The purpose of this study was to evaluate dentin tubule occlusion and remineralization competence of various toothpastes containing fluoride, bioactive glass (BG), and hydroxyapatite (HAP) as active ingredients.

Materials And Methods: Sixty dentin discs that were etched with ethylene-diamine-tetraacetic acid (EDTA) were randomly divided into nine groups. The first five groups containing eight dentin discs corresponded to subsequent brushing experiments: control, distilled water, fluoride toothpaste, BG toothpaste, and HAP toothpaste. Scanning electron microscopy (SEM) was used to demonstrate tubule occlusion after 7 days of simulated brushing (twice a day for 2min), which was followed by a citric acid challenge. The discs were stored in freshly prepared artificial saliva (AS) after every brushing cycle. The remaining four groups that contained five discs each received the following treatment: discs kept in distilled water (control), discs kept in a mixture of AS (pH 7.2) and 2g fluoride toothpaste, discs kept in a mixture of AS and 2g BG toothpaste, and discs kept in a mixture of AS and 2g HAP toothpaste. These discs were left in the mixture for one week at 37°C and were then examined under SEM. The pH of the leftover mixture was analyzed using a pH meter. The Wilcoxon signed-rank test was used to identify any statistically significant differences (p<0.05).

Results: All toothpastes demonstrated tubule occlusion after simulated brushing experiments. However, after the citric acid challenge, particles of fluoride toothpaste were completely washed away from the tubules whereas HAP and BG toothpastes demonstrated tremendous resistance to the acid challenge. After immersion of the discs in the mixture of AS and toothpaste, HAP and BG toothpastes again showed superior tubule occlusion in comparison to the other groups, but the highest pH increase was observed for fluoride toothpaste after mixing the toothpastes in AS.

Conclusion: The results of this study demonstrate that the highest tubule occlusion competence (both pre-and post-citric acid challenge) was achieved by HAP toothpaste, followed by BG toothpaste. After mixing the toothpastes in AS, the highest pH increase was observed for fluoride toothpaste, showing its superior remineralization and buffering capacity.
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http://dx.doi.org/10.1016/j.archoralbio.2015.05.012DOI Listing
September 2015

Ethnicity and Pathways of Fear in Endodontics.

J Endod 2015 Sep 28;41(9):1437-40. Epub 2015 May 28.

School of Dentistry and Oral Health, Griffith University, Southport, Gold Coast, Australia. Electronic address:

Introduction: Cultural competencies in multicultural societies with different ethnic perceptions pose a challenge during the management and treatment of patients with dental fear and anxiety. This study aimed to identify the most common and relevant pathways of fear and anxiety related to root canal treatment in different ethnic groups.

Methods: All participants visiting the Griffith University Dental Clinics, Gold Coast, Australia, were invited to participate if they had undergone primary root canal treatment or were scheduled to undergo the same. Patients with mental disabilities, those with no history of root canal treatment, those who only had surgical root canal treatment, and those below 20 years old were excluded. All participants completed the "My Endodontic Fear questionnaire."

Results: Eight hundred seventy-nine patients (20-90 years old) who had root canal treatment or were scheduled to have one consented to participate in this study. White (54.5%) and Arab/African respondents (30.9%) were more likely (P < .001) to use the conditioning pathway compared with East Asian (10.5%) or Aboriginal/Pacific Islander groups (3.9%). Age was a significant factor for all ethnicities (P < .05); 40-year-old and 65+-year-old groups showed less fear compared with the 20- to 39-year old groups. Female sex was significantly related to the use of the informative (P < .001) and parental (P = .002) pathways.

Conclusions: The present study showed that different pathways appear to be adopted by different ethnic groups, indicating the importance of customizing strategies in a multicultural society to manage fear and anxiety related to root canal treatment.
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http://dx.doi.org/10.1016/j.joen.2015.04.014DOI Listing
September 2015

CREATING: a sustainable plan for biomedical higher education in Saudi Arabia. Phase I.

Int J Health Sci (Qassim) 2015 Jan;9(1):93-103

Faculty of Medicine, King Abdul Aziz University, KSA.

Biomedical higher education has been acquiring increasing importance worldwide, including the Kingdom of Saudi Arabia, and effective strategies to improve outcomes and competitiveness are key for academic success. The plan presented here is divided into two major phases. Phase 1 (Communication, Research governance, Education planning, Accreditation) deals mainly with adopting a systematic approach to academic activities according to the current international standards. In other words, the aim is to re-organise what is already in place, taking into account current guidelines and strategies that help improve quality of education and research. It is suggested that this is not necessarily to be achieved by major investments but, rather, by a more imaginative and structured work plan. In Phase 2 (Translational practice, Implementation, Networking, Growth), higher education institutions are expected to invest in new strategic resources, to establish strong reciprocal links with international academic partners and industry, and to shift their attention to the hot topics and current academic challenges, leading the way in translational education models and pioneering cutting-edge research.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4394945PMC
January 2015

Preclinical endodontic teaching. A survey of Saudi dental schools.

Saudi Med J 2015 Jan;36(1):94-100

Department of Restorative Dental Sciences, College of Dentistry, University of Dammam, Dammam, Kingdom of Saudi Arabia. E-mail.

Objectives: To provide an overview of the general curricula in preclinical endodontic training from 6 established dental schools in Saudi Arabia.

Methods: This study was conducted in January 2014 including only schools that had more than 2 groups of student graduates prior to the study. We included 2 dental schools from the Central region, one from Qassim region, one from the Makkah region (west), one from Abha region (south west), and one from the eastern region. An internet-based questionnaire was sent to the course directors of preclinical endodontics department of the 6 schools. The survey comprised 20 questions that examined various aspects of preclinical endodontics.

Results: It was demonstrated that a significant number of faculty members had Doctor of Philosophy (PhD) degrees (n=21), Master's degrees (n=15), and Saudi board certifications (n=8). We determined that the faculty to student ratio varied from 2:1 to 8: 1 among the colleges. The participating dental schools were found to teach the Step Back, as well as the Step Down techniques for root canal preparation. Five of the 6 schools implemented the use of nickel titanium rotary instruments. All dental schools predominantly used radiographs as the means of the working length determination.

Conclusion: The curriculum for preclinical endodontics in Saudi Arabia is comparable to that followed in most European countries. A more comprehensive survey is needed that would involve more schools to formulate generalized guidelines for preclinical endodontic training in Saudi Arabia. 
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http://dx.doi.org/10.15537/smj.2015.1.9336DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4362196PMC
January 2015

Pathways of fear and anxiety in dentistry: A review.

World J Clin Cases 2014 Nov;2(11):642-53

Ava Elizabeth Carter, Geoff Carter, Roy George, School of Dentistry and Oral Health Griffith University, Southport, Gold Coast, QLD 4215, Australia.

The aim of this article was to analyze the theories underpinning dental fear, anxiety and phobias. To be included, articles must have been published between the years of 1949 and 2013 concerning fears and phobias within dentistry and/or psychiatry. Of 200 articles originally under review, 140 were included and reviewed by the authors.Five specific pathways relating to dental fear and anxiety were identified; Cognitive Conditioning, Informative, Visual Vicarious, Verbal Threat, and Parental. Eight currently accepted management techniques across all dental disciplines for dental fear and anxiety were identified. Further research is required to identify clinical diagnosis and treatment for fears originating from different pathways.
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http://dx.doi.org/10.12998/wjcc.v2.i11.642DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4233415PMC
November 2014

Perceived quality, clarity, and accuracy of manually processed and self-developing radiographs in endodontics.

Int J Health Sci (Qassim) 2013 Jun;7(2):116-23

Department of Restorative Dental Sciences, College of Dentistry, University of Dammam, Saudi Arabia.

Objectives: To evaluate perceived quality, clarity, and accuracy of self-developing films compared to conventional D- and E-speed manually processed films, and to evaluate their ease of use and satisfaction amongst pre-clinical dental students.

Methodology: Mesiobuccal root canals of 30 extracted mandibular molar teeth were instrumented and size 10 K-files were glued into the canals at 3 different levels. Each tooth was exposed thrice with the same angulation using conventional E-speed, D-speed, and self-developing films. Conventional films were processed manually and self-developing films according to the manufacturer's instructions, which required 50 seconds of contact time with the solution. Radiographs were evaluated by 4 examiners for quality, clarity, and apical position of the file. A questionnaire-based survey was conducted to evaluate the ease of use, quality, and satisfaction of undergraduate students. Data were analyzed using one-way ANOVA and Tukey-Kramer multiple comparison test, significant at p < 0.05.

Results: The quality and clarity of conventional E-speed films was perceived as significantly better than that of D-speed and self-developing films (p < 0.05). There was no statistically significant difference amongst the 3 film types for recorded file positions (p > 0.05). The results of the student survey corroborated the examiners' views that the self-developing radiographic films were of poor quality.

Conclusion: Manually processed E-speed films provided significantly superior quality and clarity of images, but for apical file position, no significant differences were found amongst the 3 film types. Conventional E-speed, D-speed, and self-developing films are all adequate for measuring endodontic working lengths.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3883600PMC
http://dx.doi.org/10.12816/0006034DOI Listing
June 2013

Pemphigus vulgaris autoimmune globulin induces Src-dependent tyrosine-phosphorylation of plakophilin 3 and its detachment from desmoglein 3.

Autoimmunity 2014 Mar 16;47(2):134-40. Epub 2013 Dec 16.

Melbourne Dental School & Oral Health CRC, The University of Melbourne , Melbourne , Australia .

The cell adhesion molecule plakophilin 3 (Pkp3) plays an essential role in the maintenance of skin integrity and is targeted in certain autoimmune conditions. In one example, we have shown that Pkp3 is instrumental in mediating the discohesive effects of sera from patients with pemphigus vulgaris (PV), a life-threatening autoimmune disease that targets intercellular adhesion in the epidermis. In the present study, we determine the effect of PV autoimmune globulin (PV IgG) on Pkp3 in an in-vitro model of PV. We demonstrate that Pkp3 becomes tyrosine phosphorylated as early as 30 min upon binding of PV IgG to keratinocyte surface and eventually detaches from its binding partner desmoglein 3 (Dsg3). In parallel, Pkp3 is depleted from the membrane (Triton X-soluble) fraction and accumulates in the cytoplasm within 240 min of incubation with PV IgG. Inhibition of Pkp3 phosphorylation by a Src inhibitor attenuates the discohesive effects of PV IgG. Taken together, the data demonstrate that activation of Src-kinase signalling is crucial for PV acantholysis and acts, at least in part, via phosphorylation of the adaptor protein Pkp3.
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http://dx.doi.org/10.3109/08916934.2013.866100DOI Listing
March 2014

IL-17 receptor A signaling is protective in infection-stimulated periapical bone destruction.

J Immunol 2013 Aug 17;191(4):1785-91. Epub 2013 Jul 17.

Department of Restorative Dental Sciences, College of Dentistry, University of Dammam, 1982 Dammam, Saudi Arabia.

IL-17 is a pleiotropic cytokine produced by Th17 T cells that induces a myriad of proinflammatory mediators. However, different models of inflammation report opposite functional roles of IL-17 signal in terms of its effects on bone destruction. In this study we determined the role of IL-17RA signal in bone resorption stimulated by dentoalveolar infections. Infrabony resorptive lesions were induced by surgical pulp exposure and microbial infection of mouse molar teeth. IL-17 was strongly induced in periapical tissues in wild-type (WT) mice by 7 d after the infection but was not expressed in uninfected mice. Dentoalveolar infections of IL-17RA knockout (KO) mice demonstrated significantly increased bone destruction and more abscess formation in the apical area compared with WT mice. Infected IL-17RA KO mice exhibited significantly increased neutrophils and macrophages compared with the WT littermates at day 21, suggesting a failure of transition from acute to chronic inflammation in the IL-17RA KO mice. The expression of IL-1 (both α and β isoforms) and MIP2 were significantly upregulated in the IL-17RA KO compared with WT mice at day 21 postinfection. The development of periapical lesions in IL-17RA KO mice was significantly attenuated by neutralization of IL-1β and MIP2. Taken together, these results demonstrate that IL-17RA signal seems to be protective against infection-induced periapical inflammation and bone destruction via suppression of neutrophil and mononuclear inflammation.
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http://dx.doi.org/10.4049/jimmunol.1202194DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767040PMC
August 2013

The uptake of nickel-titanium rotary files in saudi arabia.

Authors:
Emad Alshwaimi

Int J Dent 2012 10;2012:484291. Epub 2012 Apr 10.

Restorative Dental Sciences Department, College of Dentistry, University of Dammam, 7440 AlHosam, Dammam 32222-4371, Saudi Arabia.

Aim. We surveyed the uptake of nickel-titanium rotary files (NTRFs) among all dentists in Saudi Arabia. Methodology. A questionnaire encompassing endodontic performance and NTRF uptake was e-mailed to all members of the Saudi Dental Society. Data were collected from participants during a three-month period and were analyzed using χ(2) tests and correlation coefficients. Level of significance was set at P = 0.05. Results. The overall response rate was 30.6% (n = 490), and 82.9% were found to perform root canal treatment (RCT). Among the 406 RCT performers, general dentists formed the bulk (45%). Among endodontists, 91.5% were using NTRF (P < 0.001). Those who graduated between 1991 and 2000 used NTRF more than any other group did (78.4%, P = 0.05). Graduates from Europe and Australia used NTRF most frequently (100%, P = 0.001), followed by those from North America (87%, P = 0.001), and finally by Saudi Arabian graduates (68.7%). Male respondents performed more endodontic procedures and used NTRF significantly more often than female respondents did (males: 73%; females: 56.2%) (P = 0.001). The most significant reasons for not using NTRF were "unavailability" (64.7%, P ≤ 0.05) and "lack of experience" (54.1%, P ≤ 0.001). Conclusions. We found that NTRF usage was not as widespread in Saudi Arabia as in other developing countries. Therefore, we suggest an improved implementation of NTRF in undergraduate and postgraduate curriculums and the provision of educational courses with a greater focus on this development.
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http://dx.doi.org/10.1155/2012/484291DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3332188PMC
August 2012

Bacteria-reactive immune response may induce RANKL-expressing T cells in the mouse periapical bone loss lesion.

J Endod 2012 Mar 24;38(3):346-50. Epub 2012 Jan 24.

Department of Immunology, The Forsyth Institute, Cambridge, Massachusetts, USA.

Introduction: The present study investigated whether bacteria infecting the root canal can activate any infiltrating T cells to produce receptor activator of nuclear factor kappa B (NF-κB) ligand (RANKL).

Methods: Using a mouse model of periapical lesion induced by artificial dental pulp exposure, the presence of RANKL-positive T cells and osteoclasts in the periapical lesion was examined by an immunohistochemical approach. The bacteria colonizing the exposed root canal were identified by 16S ribosomal RNA (rRNA) sequence analysis. The isolated endodontic bacteria were further immunized to normal mice, and soluble activator of NF-κB ligand (sRANKL) production by the T cells isolated from the immunized mice was evaluated by ex vivo culture system.

Results: RANKL-positive T cells along with TRAP+ osteoclasts were identified in periapical bone resorption lesions. The gram-negative bacterium Pasteurella pnumotropica, which was most frequently detected from the root canal of exposed pulp, showed remarkably elevated serum immunoglobulin G (IgG)-antibody response in pulp-exposed mice compared with control nontreated mice. Immunization of mice with P. pneumotropica induced not only serum IgG-antibody but also primed bacteria-reactive T cells that produced sRANKL in response to ex vivo exposure to P. pneumotropica.

Conclusions: T cells infiltrating the periapical region express RANKL, and the endodontic bacteria colonizing the root canal appear to induce RANKL expression from bacteria-reactive T cells, suggesting the possible pathogenic engagement of the immune response to endodontic bacteria in the context of developing bone resorptive periapical lesions.
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http://dx.doi.org/10.1016/j.joen.2011.12.029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3291477PMC
March 2012