Investigating In Situ Expression of Neurotrophic Factors and Partner Proteins in Irreversible Pulpitis.

INTRODUCTION: In situ assessments of neurotrophic factors and their associated molecular partners have not been explored to date, particularly in humans. The present investigation aimed to explore the expressional dysregulation of neurotrophic factors (nerve growth factor [NGF], brain derived neurotrophic factor [BDNF], and NT4/5), their receptors (TrkA and TrkB), and their modulators (USP36 and Nedd4-2) directly in irreversibly inflamed human pulp tissues. METHODS: Forty samples each of healthy and irreversibly inflamed pulp were extirpated for the study. Immunohistochemical examinations were carried out for the anatomic changes and expression of neurotrophic factors and partner proteins. Expression was digitally quantified using the IHC profiler module of ImageJ and deduced as optical density. Statistical analyses were carried out by GraphPad Prism. RESULTS: Decrease in nuclear and vessel diameters was observed in irreversibly inflamed pulp tissues. NGF and BDNF were found to be significantly upregulated in symptomatic irreversible pulpitis (SIP), whereas no significant difference was observed in the expression of TrkA and TrkB. Expression of Nedd4-2, USP36, and TrkA was found positively correlated with the NGF in healthy pulp tissues. However, in SIP, positive correlation was only observed between the expression of USP36 and NGF. Among the ligands, BDNF expression was found positively correlated with NGF in healthy pulp but not with NT4/5. In the case of SIP, no correlation was observed between any neurotrophic factors. CONCLUSIONS: Upregulation of NGF, BDNF, USP36 and Nedd4-2 in SIP indicates dysregulation in the molecular events underlying the disease biology and could be exploited as potential markers for the disease diagnosis.

Comparative evaluation of Sapindus Mukorossi extract with 17% EDTA on smear layer removal in various parts of the tooth root.

OBJECTIVES: This study aimed to compare the effectiveness of an experimental root canal irrigant and 17% Ethylene-di-amine tetra acetic acid for removal of the smear layer in the coronal, middle and apical portions of the root canal. MATERIALS AND METHODS: Ninety human single rooted maxillary and mandibular teeth were selected for this study. The teeth were randomly divided into two experimental groups and one control group as follows: Group A (Ethanolic extract of Sapindus Mukorossi), Group B (17% EDTA), and Group C (Distilled water). The root canals of all three groups were prepared with stainless steel K-files by means of the standard step-back technique and irrigated with 5.25% sodium hypo chloride. The teeth were decoronated, following the irrigation and divided longitudinally into two-halves and visualized using scanning electron microscope (SEM) for the amount of smear layer present utilizing the three-point score system. The observations were noted both before and after the treatment. Nonparametric tests were applied for the comparison and p-value ⩽ 0.05 was considered as statistically significant. RESULTS: It was evident from that smear layer was completely removed in coronal portion of 27 out of 30 teeth in-group A. For middle and apical areas of group A, 24 and 19 teeth showed complete smear layer removal. In-group B it was found that there were 24, 21, and 3 teeth at coronal, middle and apical, areas respectively where smear layer were completely absent. Intra group comparison showed a significant difference (p = 0.002) in smear layer removal was found for group A at coronal, middle and apical thirds. Similarly, a significant difference (p = 0.001) was also found for group B; however heavy smear layer was found among the three parts of the canal for group C. CONCLUSIONS: Ethanolic extract of Sapindus Mukorossi have higher effectiveness in removing the smear layer from the root canal in comparison to 17% EDTA.

Effect of Erosive Agents on Surface Characteristics of Nano-Fluorapatite Ceramic: An In-Vitro Study.

Erosive beverages cause dissolution of natural teeth and intra-oral restorations, resulting in surface characteristic changes, particularly roughness and degradation. The purpose of this study was to evaluate the surface roughness and topography of a dental ceramic following immersion in locally available erosive solutions. A total of 160 disc specimens of a nano-fluorapatite type ceramic (12 mm diameter and 2 mm thickness) were fabricated and equally distributed into two groups (n = 80) and then evenly distributed among the following five testing groups (n = 16): lemon juice, citrate buffer solution, 4% acetic acid, soft cola drink, and distilled water which served as a control. The surface roughness (Ra) and topography were evaluated using a profilometer and scanning electron microscope at baseline, 24 h, 96 h, and 168 h respectively. Data were analyzed using ANOVA and Tukey's multiple comparisons (p ≤ 0.05). Surface changes were observed upon exposure to all acidic beverages except distilled water. Amongst all immersion media, 4% acetic acid produced the most severe surface roughness across all time periods (i.e., baseline, 24 h, 96 h, and 168 h). A statistically significant difference in the surface roughness values between all immersion media and across all four time intervals was observed. Erosive agents had a negative effect on the surface roughness and topography of the tested ceramic. The surface roughness increased with increased storage time intervals.

An In-Vitro Evaluation of Microleakage in Resin-Based Restorative Materials at Different Time Intervals.

A vital feature of conservative dentistry is the adhesion of the restorative material to the tooth structure for restoration of the tooth substance lost due to dental decay, trauma, or dental imperfections. In a perfect world, a restorative material should generate a lasting adhesion by bonding the restoration with tooth tissues. The ingress of micro-organisms, oral fluids, molecules, and ions through microscopic spaces due to faulty adhesion between restoration and tooth structure is known as microleakage. This study is focuses on the evaluation of adhesive failures between the restorative materials. In the past, studies have focused more on the bonding potential of a restorative material with the tooth surface. Therefore, there is need to carry out a study that compares the microleakage between resin-based restorative materials in a sandwich manner with and without the intermediate bonding layer after immersion in 2% methylene blue dye at different time intervals. The restorative materials used were composite Ceram X Mono plus (DENTSPLY) and Z350 (3M ESPE), Vitremer resin modified glass ionomer cement (RMGIC) (3M ESPE), smart dentine replacement SDR (3M ESPE), Bond NT (DENTSPLY), and Universal Bond (3M ESPE). A light emitting diode (LED) was used to cure the specimens. Artificial saliva was used as a storage medium for the specimens. Thermocycling of specimens was carried out at 500 cycles/30 s and 1000 cycles/30 s. The world health organization (WHO) grading tool for microleakage was used to analyze fluid ingress in the specimens through disclosing by 2% methylene blue dye. The statistical analysis was carried out with one-way analysis of variance (ANOVA) and Tukey post hoc test, keeping the level of significance at p ≤ 0.05. In Grade 0 = 85 samples, Grade 1 = 10 samples, Grade 2 = 7 samples, Grade 3 = 16 samples, and in Grade 4 = 2 samples were identified. This study describes that no microleakage was observed in SDR and resin composite groups as compared to Vitremer and resin composite groups.

Effect of pre-cooling agent on intensity of pricking pain at intraoral injection site in adults: An experimental study.

OBJECTIVE: To determine the effect of pre-cooling agent on the intensity of pricking pain at the intraoral injection site in adult patients. METHODS: The in-vivo interventional study was conducted at the Department of Operative Dentistry, Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences, Karachi, from September 2018 to August 2019, and comprised adult patients of either gender. The pricking pain perception during needle administration was assessed using split-mouth technique. Topical anaesthesia benzocaine gel was applied on the left side, which was treated as controls, for 1 min, while on the right side, which was treated as the experimental side, refrigerated cartridge was placed for 2 min. Infiltration anaesthesia was then administered on both sides. Pain perception ratings were measured through visual analogue scale. After profound anaesthesia was achieved, restorative treatment was performed under rubber dam isolation. Data was analysed using SPSS 24. RESULTS: Of the 152 subjects, 77(50.65%) were females and 75(49.34%) were males. The overall mean age was 35.97±8.669 years (range: 21-50 years). The effect of refrigerated cartridge was significant on the intensity of pricking pain at the intraoral injection site in patients aged 41-50 years, and in female patients aged 21-30 years (p<0.05), whereas its effect was non-significant in males aged 21-30 years and patients aged 31-40 years (p>0.05). CONCLUSIONS: Pre-cooling agent was found to be effective in decreasing pricking pain felt by patients.

Comparison of gingival biotype in smokeless tobacco users (Gutka and Paan) and non-tobacco users.

OBJECTIVE: To assess the gingival biotypes in smokeless tobacco (Gutka and Paan) users and compare it with non-tobacco users in Karachi sub-population using trans-gingival probing method (TRAN). METHODS: This in-vivo, cross sectional study was conducted in the department of Operative Dentistry from 20th February 2019 to 25th June 2019 Dow University of Health Sciences, Karachi after obtaining ethical approval from the Institutional review board of DUHS (Ref: IRB-1207/DUHS/Approval/2019/21). A total of 70 participants, 35 subjects currently using smokeless tobacco (Gutka and Paan) and 35 non-tobacco users from both genders were included in the study after taking informed consent. Gingival biotype was recorded using probe transparency method. Probing of the gingival sulcus was performed at the mid-buccal aspect of both maxillary incisors. Depending on the visibility of the underlying probe gingiva was categorized as thin or thick. RESULTS: Statistically significant differences in gingival biotype was observed of both groups (p=0.005). Males were recorded with a higher percentage of thick gingiva in both groups (81% in smokeless tobacco and 65% in non-tobacco) while in females thick gingiva was more prevalent in smokeless tobacco group (85.7%) whereas thin gingiva was noted in non-tobacco group (66.7%); although the results between genders was statistically insignificant. The comparison between different age groups, genders and both groups was statistically insignificant. CONCLUSIONS: Significant difference was observed between gingival biotype of smokeless tobacco and non-tobacco user groups. No statistically significant results were observed between genders and age groups.

Audiovisual Distraction: A Pricking Pain Reduction Modality among Ladies Receiving Intraoral Injections.

OBJECTIVE: To determine the effect of audiovisual distraction (AVD) using virtual reality device (bobo VRZ4-VRBOX) on intensity of pricking pain at the intraoral injection site among different age groups in ladies. STUDY DESIGN: Experimental study. PLACE AND DURATION OF STUDY: Department of Operative Dentistry, Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences, Karachi, during September 2018 to March 2019. METHODOLOGY: An in-vivo interventional study, using split-mouth technique was conducted in 50 lady patients of sample size of 50, to investigate pricking pain perception during needle insertion. Topical anesthesia (benzocaine gel) was applied on left side (control) for 1 minute without audiovisual distraction (AVD); whereas, on the experimental side (right), similar methodology was followed after topical anesthesia but with AVD via VR-Z4 video eyeglasses after the local anesthesia was administered. Patients' pain perception ratings were measured through visual analog scale (VAS). After profound anesthesia was achieved, restorative treatment was performed under rubber dam isolation. RESULTS: Audiovisual (AV) device was effective in decreasing the pricking pain sensed by the patients during infiltrate anesthesia; but the score remained within the same pain category. The effect of audiovisual distraction (AVD) using virtual reality device (VRZ4-VRBOX) was statistically insignificant on intensity of pricking pain at the intraoral injection site among different age groups in ladies. CONCLUSION: AV device is not dependent on age (21-50 years) in reducing the pricking pain. Pain is effectively reduced after the use of AV device, but this reduction is not statistically significant.

An In-VitroEvaluation of Microleakage at the Cervical Margin Between two Different Class II Restorative Techniques Using Dye Penetration Method.

OBJECTIVE: To evaluate the coronal microleakage of packable composite using conventional incremental and posterior bulk fill flowable composite using Smart Dentine Replacement Single Step technique in the cervical margins of class II cavities in dentine using the dye penetration method. STUDY DESIGN: In-vitroInterventional study. PLACE AND DURATION OF STUDY: Department of Operative Dentistry, Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences (DIKIOHS), Karachi, from November 2012 to April 2013. METHODOLOGY: One hundred and twenty extracted teeth (molars and premolars) were collected and randomly divided into two experimental groups (n=60 each) and were stored in normal saline until used. Fractured samples were excluded. Standardized class II proximal box only cavities were prepared and restored with conventional methacrylate based composite using incremental technique (Group A, n=40) and low stress methacrylate resin based composite SDR using single step technique (Group B, n=40). Samples were sectioned horizontally below the cervical margins and specimen disks were prepared. The specimens were thermocycled and sealed with acid resistant varnish leaving a 1-mm interface around cervical margin and immersed in 2% methylene blue buffered solution for 24 hours. Leakage was scored 0 - 4 and measured in mm. It washed and sectioned to evaluate under stereomicroscope. RESULTS: Mean penetration was 2.4280 ±0.79 mm for Group Aand 1.015 ±0.45 mm for Group B (p < 0.001). Maximum dye penetration score for group Awas 4 and group B was 3. CONCLUSION: SDR technique in combination with total etch technique at the cervical margin of class II restorations improved the marginal seal, when were placed in dentine and thermocycled.

Effect of different irradiation times on microhardness and depth of cure of a nanocomposite resin.

OBJECTIVE: To determine the microhardness and depth of cure of nanocomposite using different irradiation times on both upper and lower surfaces of composite material. STUDY DESIGN: In-vitro experimental study design. PLACE AND DURATION OF STUDY: Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences and NED University of Engineering and Technology, Karachi, from March to May 2010. METHODOLOGY: Total 120 cylinder shaped specimens; 60 specimens for depth of cure test and 60 specimens for micro hardness test were fabricated using A3 shade of nanocomposite (Filtek Z350 XT, 3M ESPE). For each irradiation time four groups were made (Group 1 = 20s), (Group 2 = 30s), (Group 3 = 40s) and (Group 4 = 60s). For each group fifteen specimens were used. The resin was placed and polymerized into a cylindrical plastic mold. Depth of cure was measured by using micrometer. Micro Vickers hardness was measured on both top and bottom surfaces. SPSS-16.0 was used for statistical analysis. RESULTS: There was statistically significant difference in the depth of cure between all groups showing the highest value in group 4 (p < 0.001). For hardness on top surface, there was a statistically significant difference in between groups 1 and 2 (p=0.001), groups 1 and 3 (p < 0.001), groups 1 and 4 (p < 0.001). There was no statistically significant difference between groups 2 and 3, groups 2 and 4 and in between groups 3 and 4. For hardness on bottom surface, there was statistically significant difference in between all groups showing the highest value in group 4 (p < 0.001). CONCLUSION: Depth of cure and hardness was increased by increasing irradiation time. Hardness on the top surface was higher than bottom surface values.