Objectives The main aim of this study was to determine the undergraduate dental students’ self-reported effectiveness of online classes offered by various dental institutes of Pakistan. Materials and Methods A cross-sectional study was conducted using an online survey. A pretested and validated questionnaire comprising of 31 questions was circulated among dental students. The study participants were inquired about the perceived level of accessibility of resources and the effectiveness of online teaching. The data was analyzed using SPSS version 24. Mann–Whitney U test and Kruskal–Wallis test were used for statistical analysis at p ≤0.05. Results A total of 1,207 students from all over Pakistan responded. The majority of students was dissatisfied with the institutional learning management system and quality of learning resources available. Students were also dissatisfied with the level of training of teachers for online lectures. The worst rating was reported for questions related to the effectiveness of online classes (average rating: 3.83 and 3.781/5). First-year students reported poor interaction with teachers (p < 0.001) and strongly disagreed with the effectiveness of online classes (mean rating: 4.14 ± 0.935). Conclusions The results from the present survey showed that dental students of Pakistan unanimously voiced dissatisfaction toward various elements of online teaching sessions. Findings from this survey will aid the academic institutes to establish proficient learning platforms focused on improving students` learning experience.

Background Root debridement procedures for the treatment of periodontal diseases, produces root surface irregularities and smear layer on the root surface that can adversely affect the healing of periodontal tissues. The objective of the present study was to evaluate the surface texture of root after hand instrumentation with Gracey curette, After Five curette, and Mini Five curette. Methods A randomised, controlled clinical trial was conducted with 120 participants clinically diagnosed with chronic periodontitis. Participants were equally randomised into four groups, with parallel treatment assignment of scaling and root planning using Gracey Curettes, After five and Mini five curette, and a control group with no instrumentation. Mobile teeth of these patients were then extracted atraumatically and analysed under a Scanning Electron Microscope and graded for "Roughness and Loss of Tooth substance index" and "Smear layer index." Cross Tabulation was made between the test groups (Control, Gracey Curette, After five, and Mini Five) versus "Roughness and Loss of Tooth substance Index" and "Smear Layer Index." A Chi-square test with Bonferroni correction was used to determine the graded distribution among the groups. Results In the control group, 73.3% of the teeth showed grade 1 roughness. In the Gracey group, 56.7% showed grade 2 roughness; in the After 5 group, 70% showed grade 3 roughness; in the Mini 5 group, 76.7% showed grade 3 roughness. A significant association was found between roughness scores and the use of individual instruments. Regarding smear layer formation, 46.7% of teeth showed a grade 4 smear layer in the control group. 50% of teeth showed grade 2 smear layer thickness in the Gracey group. In the After 5 group, 73.3% of teeth showed a grade 1 smear layer, while in the Mini 5 group, 80.0% showed a grade 1 smear layer. The use of individual instruments was significantly associated with the smear layer scores. Conclusion Gracey curettes produced relatively smoother root surfaces with less smear layer formation than After Five and Mini Five curettes, which produced relatively more roughened root surfaces with thicker smear layer formation. Trial registration ID: ClinicalTrials.gov Identifier: NCT04216966 Date of Registration: January 3, 2020.

OBJECTIVE: To investigate the effect of nickel titanium rotary endodontic file immersion in hydrogen peroxide on cyclic fatigue resistance. METHODOLOGY: Twenty Six Protaper Universal (Dentsply Maillerfier) F1 files were randomly divided into two experimental groups. In Group I, Protaper universal variable taper F1 files were immersed in normal saline where as in Group II, the files were soaked in hydrogen peroxide (6% w/v) for 2 hours at 37°C. Cyclic fatigue of each file was checked by recording the number of rotations required to break a file in a 90°curve with a 5 mm radius. For statistical analysis of data, Two-way ANOVA was applied. A p value of <0.05 was considered significant. RESULT: Out of Twenty Six, Six files fractured spontaneously after immersion in hydrogen peroxide. Twenty files were subjected to fracture resistance testing. Statistically significant difference in cyclic fatigue resistace between the two groups was found (p=0.002). The files soaked in Group II required less revolutions to fracture than the ones immersed Group I. CONCLUSION: The immersion of NiTi endodontic files in hydrogen peroxide significantly reduces cyclic fatigue resistance. Therefore, immersion of the NiTi endodontic files in hydrogen peroxide solution for removal of clogged debris should be discouraged. KEYWORDS: Cyclic fatigue, Endodontic instruments, Hydrogen peroxide, NiTi HOW TO CITE: Sarwar H, Naeem MM, Shabbir S, Riaz S, Afaq H, Shabbir J. Effect of hydrogen peroxide on cyclic fatigue resistance of NiTi endodontic files. J Pak Dent Assoc 2020;29(4):246-248.

BackgroundProbiotics are viable microorganisms, which if delivered in appropriate dose can provide health benefits. Lactobacillus reuteri (DM17938+ATCC PTA 5289) has been recommended as a safe choice for probiotics. The objective of this study is to compare the improvement in the periodontal parameters amongst smokers with generalized periodontitis with Stage III, Grade C treated with nonsurgical periodontal treatment (NSPT) to which either an antibiotics or probiotics were given as an adjuvant.MethodsSixty smokers with Stage III, Grade C generalized periodontitis were randomized in two groups after taking informed consent. Periodontal parameters including bleeding on probing (BOP), probing depth (PD), attachment loss (AL), gingival index (GI), and plaque index (PI) were recorded. Group 1 received (after NSPT and oral hygiene instructions) amoxicillin and metronidazole for 7 days and a placebo for probiotics for 30 days. Group 2 was provided (after NSPT and oral hygiene instructions) with one tablet of Lactobacillus reuteri probiotics (2 × 108 CFU) twice daily for 30 days and placebo antibiotics for 7 days. The periodontal parameters were recorded again at 1‐ and 3‐month follow‐ups as outcome variables. Mean, standard deviation, and confidence interval were reported using SPSS 20.0.ResultsA statistically significant clinical improvement in the PD, BOP, PI, and GI were observed in both the groups at 3‐month follow‐up. However, the AL remained unchanged in both the groups.ConclusionsAdministration of probiotics and antibiotics along with NSPT yield statistically significant differences in PD and BOP from baseline to 3‐month follow‐up. However, between the group differences were not statistically significant for the periodontal parameters (AL, PD, and BOP).

Background: Anti-bacterial effect of Miswak on microorganism has already been proven in previous researches. The Dandasa is used by most women in Saudi Arabia, India and Pakistan as a toothbrush for cleaning the teeth. Aim: This study was done for the comparison between the effect of Miswak and Dandasa in improving gingival health, as both has anti-plaque action and absence of plaque is directly proportional to gingival health. Methods: A prospective cohort study was carried out at the Department of Periodontology, Dr.Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Karachi for a period of 6 months. Total 90 patients fulfilling the inclusion criteria were included into two Groups. In group-A habitual user of miswak were taken and in group-B habitual user of dandasa were taken. The Plaque score and gingival index were made zero before the start of observation by conducting ultrasonic scaling. Results: In Group A 57.8% participants were using miswak once a day and 42.2% twice a day. In group B 44.4% participants were using Dandasa once a day 44.2% and 55.6% twice a day. Mean post-gingival index score was 1.95±0.52 in group A and 1.08±0.28 in group B. Mean post plaque index score in Group A was 1.97±0.69 and Group B was 1.15±0.36. The results portrayed significant discrepancy in pre and post gingival index. The conclusion also depicted prominent variability in pre-post-plaque index. Both indices showed that the dandasa was better at plaque control as compare to Miswak Conclusion: Mean Gingival Index (GI) and Plaque Index (PI) scores in dandasa group was prominently less as compared to Miswak group. Keywords: Gingival Index, Plaque index, Dandasa, Miswak