The purpose of this study was twofold: (1) to investigate the nature and degree of water loss at 21 degrees C, 60% relative humidity (dehydration) and at 105 degrees C (desiccation), and to relate these findings with (2) the strains produced in the dentine structure during dehydration and rehydration processes. In stage 1, digital moire interferometry (DMI) was used to study the strain distribution pattern during dehydration and rehydration at 21 degrees C. In stage 2, the nature and degree of water loss was determined using gravimetric analysis and nuclear magnetic resonance spectroscopy. DMI showed that dehydration produced strains in the dentine structure after an initial latent period. Gravimetric analysis showed that dentine exhibited an initial rapid water-loss phase followed by a slow and steady water-loss phase. Though the major portion of water loss occurred in the initial 2 h of dehydration (rapid water-loss phase), no obvious strains were produced during this period. Rehydration lead to the major reversal of dehydration-induced water loss and strains in dentine. Heating at 105 degrees C resulted in further substantial loss of water from dentine. These experiments highlighted that the free water in the dentine surface, porosities and tubules are lost rapidly and constitute the major water lost when dehydrated at 21 degrees C.

In this study, a Fiber Optic Backscatter Spectroscopic Sensor (FOBSS) is used to monitor demineralization and remineralization induced changes in the enamel. A bifurcated fiber optic backscatter probe connected to a visible light source and a high resolution spectrophotometer was used to acquire the backscatter light spectrum from the tooth surface. The experiments were conducted in two parts. In Part 1, experiments were carried out using fiber optic backscatter spectroscopy on (1) sound enamel and dentine sections and (2) sound tooth specimens subjected to demineralization and remineralization. In Part 2, polarization microscopy was conducted to examine the depth of demineralization in tooth specimens. The enamel and dentine specimens from the Part-1 experiments showed distinct backscatter spectra. The spectrum obtained from the enamel-dentine combination and the spectrum generated from the average of the enamel and dentine spectral values were closely similar and showed characteristics of dentine. The experiments in Part 2 showed that demineralization and remineralization processes induced a linear decrease and linear increase in the backscatter light intensity respectively. A negative correlation between the decrease in the backscatter light intensity during demineralization and the depth of demineralization determined using the polarization microscopy was calculated to be p = -0.994. This in vitro experiment highlights the potential benefit of using FOBSS to detect demineralization and remineralization of enamel.

OBJECTIVES: To determine the trends in endodontic protocols amongst practicing dentists in teaching institutions and private clinics in Lahore. METHODOLOGY: A cross sectional survey was conducted amongst dentists working in the teaching institutions and in the private clinics of Lahore. A pre-piloted questionnaire survey adopted from Kohli et al with slight modifications was used. In this descriptive study 270 practicing dentists were selected using consecutive sampling with a 5% level of significance and margin of error. RESULTS: The 270 respondents had a mean age of 28.16 ± 6.18 participated in this study among which 111 (41.1%) were males and 159(58.9%) were females with the mean age of 30.28 ± 7.416 and 26.68 ± 4.62 respectively (12.2%) were consultants, 175(64.8%) were general dentists whereas 62(23%) were postgraduate residents. In our study population, 76(28.1%) dentists were using magnification among which 67(88.2%) were using loupes and 9(11.8%) were using microscope. The prevalence of the rubber dam usage for isolation among our respondents was 110(40.7%) only, 201(74.4%) dentists reported for routine removal of smear layer. Manual canal preparation technique was the most commonly used method practiced by 149(55.2%) dentists. 136(50.4%) dentists were using beveled needles for irrigation, whereas only 71(26.3%) were using side venting irrigation needles. Majority of the dentists (45.2%) were not using any method to increase the efficacy of the irrigants. CONCLUSION: There are deficiencies in the endodontic protocols followed by majority of the dentists in Lahore and these short comings should be addressed by governing bodies. KEYWORDS: Root canal therapy, Endodontic, Practice Patterns, Dentists HOW TO CITE: Lodhi Sk, Ehsan S, Rafique A, Saleem MN. Trends in endodontic protocols amongst dentists in Lahore. J Pak Dent Assoc 2020;29(4):239-245. DOI: https://doi.org/10.25301/JPDA.294.239 Received: 30 July 2020, Accepted: 08 September 2020

<p><strong>Background and Objective:</strong> The Coronavirus disease 2019 first appeared in the area of Wuhan, China. Dental professionals are at greater risk of getting infected by patients and certain dental procedures involving aerosol generation and proximity to the oropharyngeal region. Therefore, Personal Protective Equipment (PPE) is recommended to protect skin and mucosa from infected blood or saliva. American Dental Association (ADA) has published recommendations for dental treatment, yet most of the dentists are still hesitant in treating patients. The objective of this study was to assess the knowledge and practices of dentists in Pakistan regarding PPE during COVID-19 pandemic. <strong>Methods: </strong>Data collection was done using a well-structured web-based questionnaire (Google forms). The survey form was disseminated by sending the link via email, WhatsApp and other online forums. <strong>Results:</strong> A total of n = 1016 responses were collected. Approximately 91.6% of the participants were young dentists with years of experience 1 &ndash; 10 years. Majority of the participants 76.7% did not have easy access to PPE. A total of 60.8% claimed to be aware of the recent World Health Organizations, Centre for Disease Control and other international guidelines to screen COVID-19 patients at their clinic. Almost all the participants, 95.6%, had never undergone N95 fit-testing in their career. More than half of the participants, 64.4% were not aware of the differences between N95, N99, N100 masks. A positive trend was observed in 91.7% of the participants when asked about washing hands or uses an alcohol-based sanitizer before every patient encounter. More than three quarter (81%) of the participants was not performing aerosol producing procedures at their practices. <strong>Conclusion:</strong> Majority of dentists were found to have adequate knowledge and practice scores, which is important to combat COVID-19. However there still many gaps in their knowledge and practices which need to be highlighted to ensure safe dental practice for both patients and dentists.</p>

Background and Objective: Coronavirus disease 2019 is the latest infectious disease to rapidly spread worldwide. The role of dental professionals in preventing the transmission of COVID-19 is critically important while providing routine dental care. The objective of this study was to assess the attitude and perception of dentists to provide treatment to patients and form a general consensus for future dental protocols.Methods: Data collection was done using a well-structured web-based questionnaire (Google forms). The survey form was distributed by sending the link via email, WhatsApp and other online forums. Data were collected from n = 299 participants and analyzed by using Statistical Package for the Social Sciences (SPSS) version 25. Frequencies and percentages were determined for qualitative variables whereas mean  standard deviation was calculated for quantitative variables.Results: A total of n = 299 responses were collected. Approximately 90.6% of the respondents were young clinicians with years of experience 1 -9 years. Most of the respondents i.e. 70.9% were more inclined towards performing only non-aerosol generating procedures. Ninety five percent agreed upon training of dentists and dental chair side assistants regarding donning and doffing of PPEs and 91% preferred to go for high volume suction for aerosol generating procedures. Ninety four percent of the respondents strongly recommended to check for every patient reporting to dental clinic. Conclusion:Majority of the dentists are well aware of the current crisis, but trends of ambiguities have been seen regarding adaptation of particular protocol for the dental treatment. Intervention from Government is required to establish proper dental guidelines including provision of PPEs so that treatment could be provided with the best of facilities to the poor patients as well.