Temporal and institutional trends in robotic surgery

Robotic surgery has become increasingly prevalent in general surgery practice. While previous studies have shown the safety and efficacy of robotic assistance in laparoscopic general surgery procedures, few studies have evaluated the temporal and regional trends in implementation. In our retrospective population-based study, we aim to evaluate the national trends in robotic surgery. National Inpatient Database (NIS 2009-2014) was used to identify adults who underwent robotic assisted surgery (ICD 9 codes 17.41 to 17.49). Robotic procedures related to seven abdominal organ systems were compared against the trends of Urology, Gynaecologic, and Orthopedic robotic procedures. Discharge weights were applied to calculate National temporal trends separated by hospital size, teaching status and US geographic region. 894,163 patients received a robotic assisted procedure between 2009 and 2014 with 64% increase in utilization. The largest percent change was witnessed in biliary robotic procedures with 2984% change in utilization, followed by hernia (1376%). Lowest percent change was witnessed in esophageal procedures with 114% increase. Medium sized hospitals had the largest change in robotic utilization (41%), with large institutions seeing 18% decrease. Gastric procedures were the most common robotic procedure performed at small institutions (7917 total cases; 316%). Large institutions saw an overall decrease in gastric (- 47%), esophageal (- 17%), small and large intestinal (-16%), and hepatic (- 7%) robotic procedures. Rural non-teaching hospitals saw the largest increase in robotic surgery (274%). Urban non-teaching hospitals saw a decrease of 29%. While urban teaching institutions saw a 20% and 6% increase in gynecological and urological procedures, an overall decrease was seen in esophageal (- 10%), gastric (- 12%), intestinal (- 11%), hepatic (- 17%), biliary (- 10%), pancreatic (- 11%) and hernia procedures (- 14%). Biliary procedures saw the largest increase in rural institutions (740 cases; 392%), followed by hernia (144% increase). South region of the nation had the largest increase in robotic procedures (23%). No change was seen in the use of robotic surgery in the northeast region with the midwest and west seeing an overall decrease (- 4% and - 22%, respectively). Our study highlights the increase in use of robotics for both general and specialty surgery, with an increase in utilization over time. Increased incidence of robotic surgery in smaller, rural institutions with overall decrease in larger, urban teaching hospitals suggests increasing comfort in robotic surgery in the community setting. Further studies are necessary to evaluate the factors associated with increased utilization in smaller institutions.

Influence of Varying Oil-Water Contents on the Formation of Crude Oil Emulsion and Its Demulsification by a Lab-Grown Nonionic Demulsifier

This study describes how varying oil/water contents affect emulsion formation and the impact they have on emulsion droplet size, viscosity, and interfacial behavior. Crude oil (continuous phase) volume fractions of 40, 50, 60, and 70 vol % were probed in the various W/O emulsions formed. Experimental results from optical morphology revealed the emulsion droplets kept reducing as the crude oil fraction kept increasing, while the droplets were nearly unnoticeable in the emulsions derived from 60 and 70% crude oil. The viscosity-shear rate of emulsions produced from 40, 50, and 60 vol % crude oil exhibited a non-Newtonian behavior owing to the substantial volume of water content in their emulsions, whereas the viscosity-shear rate of the emulsion with 70 vol % crude oil exhibited a Newtonian behavior similar to the pure crude oil, suggesting a thorough blending of oil-water at this crude oil fraction. Besides, the viscosity-temperature measurements revealed that the viscosity of these emulsions diminished as the temperature increased and the viscosity reduction became more noticeable in an emulsion comprising 70 vol % crude oil. In the interfacial assessment, the increased crude oil content in the produced emulsion led to a sharp reduction in the interfacial tension (IFT). The IFT values after 500 s contacts between the emulsion and water (surrounding phase) were 11.86, 10.02, 8.08, and 6.99 mN/m for 40, 50, 60, and 70 vol % crude oil, respectively. Demulsification experiments showed that water removal becomes more challenging with a large volume of crude oil and a small water content. Demulsification performances of the lab-grown nonionic demulsifier (NID) after 10 h of demulsification activity at room temperature (25 °C) were 98, 90, 17.5, and 10% for the emulsions formed from 40, 50, 60, and 70 vol % crude oil, respectively, indicating that the demulsification degree decreases with an increasing crude oil content. Viscosity-time determination was applied to affirm the activity of NID on the emulsion formulated with a 50% crude oil fraction. The injection of NID in this emulsion triggered a sharp viscosity reduction, indicating the adsorption of NID at the oil-water interface and disruption of emulsifiers, enabling emulsion stability.

Clinical effects of Lactobacillus reuteri probiotic in chronic periodontitis - a systematic review

OBJECTIVE

This systematic review examines the effectiveness of Lactobacillus reuteri as an adjunct to scaling and root planing in the treatment of chronic periodontitis.

MATERIALS AND METHODS

Scopus, PubMed, and Web of Science databases were searched according to specific inclusion and exclusion criteria in October 2022. Randomized control trials that evaluated the effects of Lactobacillus reuteri in patients with periodontitis were included. The primary outcome was pocket depth and clinical attachment levels, while the secondary outcome considered was bleeding on probing, microbial levels, and gingival index score. Study quality was assessed based on the Cochrane Handbook for Systematic Reviews of Interventions and the ROB2 tool.

RESULTS

A total of eleven studies that examined 369 subjects were included in the review. Adults in the age group of 18-70 years of age suffering from chronic periodontitis were evaluated. Eight out of the eleven studies reported statistically significant improvement in the intergroup pocket depths, whereas seven studies showed a statistically significant reduction in the clinical attachment levels in the probiotic group. Three studies showed no significant improvement in the pocket depth levels in the probiotic group as compared to the controls. Four studies showed no significant reduction in clinical attachment levels between the two groups. The overall risk of bias was high in four studies, while seven studies reported some concerns about the risk of bias.

CONCLUSIONS

Based on the limited evidence available, the adjunctive use of Lactobacillus reuteri to scaling and root planing may provide some additional benefit in improving periodontal parameters.

A Comparative Evaluation of Three Methods of Disinfection of Gypsum Casts and the Changes in Surface Roughness and Dimensional Accuracy after Disinfection-An Ex Vivo Study

BACKGROUND

One of the major problems of everyday dental practice is cross-contamination. It can place office personnel, dentists, and patients at risk of acquiring serious illness. Disinfection helps in controlling this cross-contamination to an extent. The evaluation was done to find the efficient disinfection method on gypsum casts.

AIMS

The aim of this study is to evaluate and compare the efficacy of three methods of disinfection of gypsum casts, namely, chemical disinfection by immersion, spray method, and microwave method, and also to evaluate and compare changes in surface roughness and dimensional accuracy between the three methods after disinfection.

MATERIALS AND METHODS

Ex vivo and experimental study. Thirty participants were selected, and impressions of the maxillary arch were made using polyvinyl siloxane impression material. Ninety type IV die stone gypsum casts were poured. It was divided into three groups and was subjected to chemical disinfection by immersion and spray methods, and microwave method. The disinfected casts were evaluated for microbial growth, surface roughness, and dimensional accuracy. It was performed by using the one-way analysis of variance test and paired t-test followed by the Kruskal - Wallis test and Wilcoxon signed rank test (α = 0.05).

RESULTS

Microwave disinfection was more effective than both immersion and spray chemical disinfection methods (P < 0.010 and <0.001). The surface roughness of the microwave-irradiated casts had significantly increased after disinfection. However, there were no significant dimensional changes by any of the methods of disinfection.

CONCLUSION

Within the limitations of the study, the microwave method of disinfection is more effective in eradicating microorganisms when compared to chemical methods of disinfection by immersion and spray methods.

Validation of Diagnostic Utility of Salivary Urea in Patients with Chronic Kidney Disease in Chennai: A Cross-Sectional Study

BACKGROUND

Serum urea levels are essential for the diagnosis of chronic kidney disease (CKD), as they are a measure of renal function. Salivary urea has been used as an alternative to serum urea in patients with CKD.

AIM

To estimate serum urea levels and their correlation with salivary urea levels in order to validate the use of saliva as an alternative diagnostic tool for renal dysfunction.

PATIENTS AND METHODS

Thirty healthy individuals and 150 patients with CKD (30 from each CKD stage) were recruited for the study. Serum and salivary samples were collected to estimate the urea levels, and statistical analyses were performed.

RESULTS

Statistically significant (P < 0.05) differences in the mean serum and salivary urea levels were observed between the healthy and each stage of the CKD group; significance at P < 0.05 was observed within the stages of CKD as well. Correlation analysis also showed significant differences between the serum and salivary urea levels at each stage of the disease. Receiver operating characteristic analysis revealed a higher area under the curve of 0.917 at a 95% confidence interval with a salivary urea cut-off of 28.25 mg/dl (sensitivity and specificity: 88% and 84%, respectively).

CONCLUSION

The variability in salivary urea levels in the early and late stages suggests the use of salivary urea in the late stages of CKD. It is suggested that salivary urea levels may be used as an alternative to serum to assess and monitor the progression of renal impairment along with other standard renal function markers.

Comparative Evaluation of Various Lens and Ring Flash Combination for Intraoral Photography

BACKGROUND

Extraoral and intraoral dental photographs serve as preoperative records and document the entire treatment. Correctly composed orthodontic photographs are crucial for remote diagnosis and may serve as a bulwark against medicolegal challenges.

MATERIALS AND METHODS

In this prospective study, intraoral frontal photographs of patients with ideal occlusion were taken using two types of lenses (EF-S 18-55 mm f/3.5-5.6 IS STM lens (Canon, Tokyo, JP), SP 90 mm F/2.8 MACRO VC lens (Model F017 Tamron, NY, USA)) and two different ring flash systems (Meike FC-100 Macro Ring LED Light (Meike, China), Macro Ring flash Lite YN-14EX (Yongnuo digital, China)). The combination of lens and flash used was grouped into four groups. Twenty-eight intraoral photographs of patients were taken. An image quality assessment survey was distributed among two groups - 50 orthodontists and 50 other dental specialists.

RESULTS

The participants were asked to assess all the intraoral images and subjectively score them on a scale of one to ten, with one being very poor and ten being excellent, considering the sharpness, color, brightness, contrast, and overall quality of the image. The general dentists rated the images taken with a 90-mm macro lens and ring flash as the best quality photographs. Images obtained using an 18-55 mm lens and ring LED received significantly lesser scores and were graded good by dentists.

CONCLUSION

This combination of lens and flash may prove a valuable investment in the long-term aiding in excellent dental images for diagnosis and treatment monitoring.

Diode laser targeting red-complex bacteria in periodontitis: a systematic review

OBJECTIVE

This systematic review examines the effectiveness of diode laser irradiation in reducing the levels of red complex bacteria as well as periodontal parameters of pocket depth and clinical attachment level.

MATERIALS AND METHODS

We conducted electronic searches across databases such as Scopus, Embase, Medline, and Web of Science databases in July 2022. Randomized controlled trials that evaluated the reduction of red-complex bacteria in patients with periodontitis using diode lasers were included. The primary focus was the reduction in the microbial count of red complex bacteria, whereas probing depth and attachment level were considered secondary outcomes. Articles in languages other than English were excluded. Study quality was assessed based on the Cochrane Handbook for Systematic Reviews of Interventions and the ROB2 tool.

RESULTS

After searching the databases, eight independent studies were included, with a sample size of 210 subjects. The average age group of the study population was 30-60 years, and there was a lack of consensus on the antimicrobial effect of diode lasers. Out of the eight studies, four studies reported no significant difference in the levels of red complex bacteria before and after laser application. Three studies reported significantly lower levels of red complex bacteria in the intergroup comparison. One study reported that laser had no significant effect on intergroup bacterial levels. The combination of diode laser irradiation with scaling reduced the count of red complex bacteria and improved the clinical parameters, although not significantly.

CONCLUSIONS

Based on the limited evidence available, the adjunctive use of diode laser for scaling and root planning may provide some additional benefit in terms of reduction of red complex bacterial count and clinical parameters. Further well-designed trials and the use of objective measures are necessary before outlining universal guidelines for best practice. The adjunctive use of diode laser in non-surgical periodontal therapy may provide a reduction in the red complex microbial count and improvement in clinical parameters, decreasing the need for periodontal surgery.

Novel Environmentally Friendly Nanomaterials for Drag Reduction of the Emulsified Acid System

Matrix acidizing is a technique that is widely used in the petroleum industry to remove scales and create channels in the rock. Removal of scales and creation of channels (wormhole) enhance productivity. Conventional acidizing fluids, such as hydrochloric acid (HCl) for carbonate and a mixture of hydrofluoric acid (HF) and HCl acid, are used for the matrix acidizing process. However, these fluids have some drawbacks, including strong acid strength, corrosion at high temperatures, and quick reactions with scale and particles. Emulsified acid systems (EASs) are used to address these drawbacks. EASs can create deeper and narrower wormholes by reducing the reaction rate of the acid due to the external oil phase. However, EASs have a much higher viscosity compared to conventional acidizing fluids. The high viscosity of EASs leads to a high drag that restricts pumping rates and consumes energy. This study aims to utilize environmentally friendly and widely available nanomaterials as drag-reducing agents (DRAs) of the EAS. The nanomaterials used in this study are carbon nanodots (CNDs). CNDs have unique properties and are used in diverse applications in different industries. The size of these CNDs is usually smaller than 10 nm. CNDs are characterized by their biocompatibility and chemical stability. This study investigates the use of CNDs as DRAs for EAS. Several experiments have been conducted to investigate the CNDs as a DRA for the EAS. The developed EAS was initially tested for conductivity and drop-test analysis to ensure the formation of an inverted emulsion. Thereafter, the thermal stability for the range of temperatures and the rheological properties of the EAS were evaluated to meet the criteria of field operation. Then flow experiments with EASs were conducted before and after adding the CNDs to investigate the efficacy of drag reduction of EASs. The results revealed that CNDs can be used as viscosity reducers for the EAS, where adding the CNDs to the EAS reduces the viscosity at two different HCl concentrations (15 and 20%). It reduces the viscosity of the EAS in the presence of corrosion inhibitors as well as other additives to the EAS, showing its compatibility with the field formulation. The drag reduction was observed at the range of temperatures investigated in the study. The conductivity, stability, and rheology experiments for the sample taken after the flow experiment are consistent, ensuring CNDs work as a DRA. The developed EAS with CNDs is robust in terms of field mixing procedures and thermally stable. The CNDs can be used as a DRA with EAS, which will reduce drag in pipes, increasing pumping rates and saving energy.

Public Awareness on Perio-systemic Interplay: A Cross-Sectional Survey in South India

BACKGROUND

The oral cavity has been referred to as "the gateway to overall health." It is also said to be the meeting point of medicine and dentistry.

AIMS

Our study sought to determine the extent to which the public was aware of the connection between oral/periodontal conditions and general health.

SETTINGS AND DESIGN

The observational cross-sectional study's questionnaire was sectioned into oral health awareness, systemic influence on oral health, and personal oral health assessment.

MATERIALS AND METHODS

A total of 994 responses were recorded and a Chi-square test was performed to uncover the relationships using SPSS version 22.0. According to responses, 70% of the population on average comprehended the responses to the majority of the oral health awareness-related questions.

RESULTS

It has been noticed that only 30% of the general public was aware of the prevalent health issues like diabetes, hypertension, and malnutrition's impact on dental health. However, more than 60% had confidence in their oral health and gave a rating of at least 5.

CONCLUSION

The study indicates that a good number of the population was prioritizing their oral health. However, there exists a definitive need to improve oral health awareness thereby ameliorating the overall health of an individual.

Evaluation of scanning accuracy for two commercially available intraoral scanners in reproducing orthodontic bracket dimensions

OBJECTIVE

The aim of this study was to compare the scanning accuracy of two different intra-oral scanners- MEDIT i500 and TRIOS 3 shape in reproducing orthodontic bracket dimensions.

MATERIALS AND METHODS

This in vivo cross-sectional study comprised seven subjects with a full complement of permanent dentition without third molars. Complete arch scanning was carried out with two intraoral scanners, such as MEDIT i500, TRIOS 3 shape, after bonding with brackets. The control group consisted of bracket dimensions measured directly by using Vernier calipers before bonding. Bracket dimensions of three-dimensional (3D) images were measured by using OrthoAnalyzer software. The accuracy of intraoral scanning was investigated by comparing bracket dimensions among the three groups using One-way ANOVA and Post-Hoc Tukey HSD test, and by evaluating outcomes for each quadrant and an individual tooth in complete-arch scans.

RESULTS

When comparing bracket dimensions of 3D images with manual measurements using a traditional Vernier caliper, MEDIT i500 showed no significant difference when compared to the control group (p>0.05) in full arch scanning as well as the quadrant and single tooth scans in complete arch scanning. TRIOS 3 shape showed a significant difference when compared to the control and MEDIT i500 group (p<0.05) for all parameters.

CONCLUSIONS

MEDIT i500 showed higher accuracy and better reproduction of orthodontic bracket dimensions than TRIOS 3 shape.

Comparison of bacterial colonization on absorbable non-coated suture with Triclosan- or Chlorhexidine-coated sutures: a randomized controlled study

OBJECTIVE

The oral cavity is a colossal reservoir for the bacteria. The healing of tissues is compromised after flap surgery, particularly in the presence of sutures, as they can act as repositories for bacteria, ultimately leading to surgical site infections. Hence, antibacterial-coated sutures have been considered as an alternative to reduce the risk of these infections and further improve the wound healing of the tissues after flap surgery. Since minimal information is available on the effect of antibacterial-coated sutures on periodontal tissues, this study aims to clinically and microbiologically assess the antibacterial efficacy of Triclosan (TCS) and Chlorhexidine-coated sutures (CCS) on periodontal tissues compared to non-coated sutures (NCS).

PATIENTS AND METHODS

A total of 75 subjects with moderate to severe periodontitis were included in the study and randomly allocated to one of the three groups, (TCS, CCS, and NCS groups) equally. Suture removal was performed on postoperative day 8, and parameters such as wound healing and post-operative pain were evaluated. The retrieved suture samples were subjected to microbiological analysis and the bacteria were identified quantitatively and qualitatively.

RESULTS

Intragroup analysis of the wound healing index and post-operative pain for all the groups showed a significant improvement (p<0.01), from day 8 to day 30. Intergroup analysis of the wound healing index revealed significant wound healing (p<0.05) on day 15 and day 30. For post-operative pain, intergroup analyses showed significantly low pain scores (p<0.01) for the TCS group. Microbiologic analysis of aerobic colony counts in both anterior and posterior regions revealed significantly (p<0.01) least colony counts in TCS and highest colony counts in NCS groups, respectively. Although anaerobic colony counts were not statistically significant, relatively fewer colony counts were identified in the TCS group. Whereas, relatively higher anaerobic colony counts were seen in the CCS group in the anterior region and in the NCS group in the posterior region. Qualitative assessment revealed higher amounts of Streptococcus and Staphylococcus species in all the three groups (TCS, CCS, and NCS groups).

CONCLUSIONS

Antibacterial-coated sutures, particularly Triclosan-coated sutures, are effective in reducing bacterial accumulation compared to non-coated sutures. Therefore, these sutures can be effectively utilized in periodontal flap surgery.

Success rate of immediately loaded implants in the posterior zone

Dental implants are considered an ideal treatment for a missing single tooth. Immediate loading of implants can hasten the procedure, providing comfort to the patients. Recently, immediate loading of implants has gained much importance as it helps hasten the procedure and provides more comfort to patients. A previous systematic review published 5 years ago compared the success rates between immediate and conventional loading. There are several factors that influence the success rate of implants that were not discussed in detail in the previous review. Hence, the present systematic review is done to report differences in the outcomes from single implant restorations of missing teeth in the posterior region in patients who were subjected to immediate loading and conventional loading. A follow up for 1 year was done. Electronic databases of Medline, Scopus, and Web of Science were searched for publications in the English Language during May 2021. The search results yielded 306 articles, out of which 225 were excluded based on title and abstract screening. Screening of the remaining 81 full text articles yielded 14 original research articles that satisfied the predefined inclusion criteria. Meta analysis was not possible due to the heterogeneity of the data. The overall success rate of the immediate loading of a single implant is 94.31%. Implants in the maxillary region had a higher survival rate than those in the mandibular region. The age range between 18 and 80 years showed good prognosis and outcomes in older individuals. Good oral hygiene was emphasized for all patients to prevent any secondary conditions or delays in healing.

A Guide for Selection of Aging Time and Temperature for Wettability Alteration in Various Rock-Oil Systems

Wettability alteration has been identified to be one of the important mechanisms to improve the microscopic recovery in many of the enhanced oil recovery (EOR) methods including polymer flood, surfactant flood, low salinity flood, microbial flood, alkaline flood, etc. Ensuring the oil-wet nature of the formation before flooding in the laboratory is necessary to study the efficiency of the EOR process, which targets microscopic recovery through wettability alteration. Nevertheless, altering the wettability depends on several parameters, such as aging time, aging temperature, core nature, oil properties, etc. Although several researchers investigated the effect of individual parameters on wettability alteration, the literature is scarce, and the question of what is the shortest and yet the most reliable aging time for ensuring wettability alteration for the specific rock-oil system at different temperatures remains unclear. This paper attempts to seek an answer to this question by compiling the relevant literature to find the effect of individual parameters such as different aging times, temperatures, oil compositions, and rock lithologies on wettability alteration. Results observed from data analysis showed different windows for aging conditions depending on the core sample lithology, initial wettability, and type of oil used. It was noticed that the higher the asphaltene content in the crude oil used, the lower the time and temperature that it takes to alter the sample wettability. Aging a sandstone core under 80 °C using crude oil with 11 wt % % asphaltene took 7 days to shift the core from strongly water-wet to neutral-wet. The same wettability alteration was achieved in 14 days when aging the sandstone sample at 90 °C using crude oil with 0.85 wt % asphaltene content. Generally, it was observed that the aging time decreased as the temperature increased. Moreover, as the sample has a lower initial water wettability condition, the time that it needs to be aged becomes higher. Results indicated that carbonates in general require less aging time to alter their wettability condition to oil-wet, around 1-7 days, compared with sandstones, around 14-21 days.

Static and dynamic adsorption of a gemini surfactant on a carbonate rock in the presence of low salinity water

In chemical enhanced oil recovery (cEOR) techniques, surfactants are extensively used for enhancing oil recovery by reducing interfacial tension and/or modifying wettability. However, the effectiveness and economic feasibility of the cEOR process are compromised due to the adsorption of surfactants on rock surfaces. Therefore, surfactant adsorption must be reduced to make the cEOR process efficient and economical. Herein, the synergic application of low salinity water and a cationic gemini surfactant was investigated in a carbonate rock. Firstly, the interfacial tension (IFT) of the oil-brine interface with surfactant at various temperatures was measured. Subsequently, the rock wettability was determined under high-pressure and high-temperature conditions. Finally, the study examined the impact of low salinity water on the adsorption of the cationic gemini surfactant, both statically and dynamically. The results showed that the low salinity water condition does not cause a significant impact on the IFT reduction and wettability alteration as compared to the high salinity water conditions. However, the low salinity water condition reduced the surfactant's static adsorption on the carbonate core by four folds as compared to seawater. The core flood results showed a significantly lower amount of dynamic adsorption (0.11 mg/g-rock) using low salinity water conditions. Employing such a method aids industrialists and researchers in developing a cost-effective and efficient cEOR process.

In Vitro Evaluation of marginal adaptation of polyether ether ketone and zirconia copings

Background

Polyether ether ketone (PEEK) has emerged as a new thermoplastic material with potential applications as a restorative material. Aim: This study aimed to evaluate the marginal adaptation of PEEK copings compared to zirconia copings using field emission scanning electron microscopy.

Materials and Methods

A freshly extracted maxillary central incisor was prepared for a full-coverage restoration following standard principles of tooth preparation. The tooth was sent to a laboratory for fabrication of samples using computer-aided design and manufacturing (CAD/CAM). Twenty samples of polyether ether ketone (PEEK) copings (group A) and 20 of zirconia copings were fabricated (group B). The copings were scanned under a field emission scanning electron microscope and measurements were taken at four distinct points. The marginal adaptation over the buccal, lingual, mesial, and distal margins for both groups was evaluated. One-way analysis of variance (ANOVA) and independent t test were applied.

Results

Our findings indicate that PEEK showed better marginal adaptation than zirconia at all measurement points. The mean marginal gap value of the PEEK group was 33.99 ± 8.81 μm and of the zirconia group was 56.21 ± 15.07 μm. On comparing marginal adaptation among the mesial, distal, buccal, and lingual aspects, PEEK showed better adaptation on all four margins, with the best adaptation on the buccal margin that had the lowest mean gap value of 29.27 ± 6.07 μm. The zirconia group adapted best at the distal margin, with a lowest mean gap value of 53.58 ± 15.25 μm (P ≤ 0.05).

Conclusion

PEEK copings had better marginal adaptation and fit compared to zirconia copings. It may have applications as a restorative material in fixed prostheses.

Root surface changes following manual and ultrasonic instrumentation - a scanning electron microscopic study

OBJECTIVE

The aim of this study is to assess the efficacy of hand and ultrasonic scaling and to evaluate the surface roughness on the root surface of periodontally involved teeth using a scanning electron microscope.

PATIENTS AND METHODS

A sample of 90 single-rooted teeth with a hopeless prognosis was selected for the study and divided into three separate groups. Group I consist of no treatment. In Group II, hand scaling was done using Gracey curettes, and in Group III, ultrasonic scaling was done. The teeth were then extracted and fixed in 10% formaldehyde solution for 24-48 hours and subjected to scanning electron microscopic (SEM) evaluation.

RESULTS

The SEM analysis revealed that the remaining calculus index was found to be similar in the ultrasonic group and the hand scaling group, whereas the surface roughness was found to be the least in the ultrasonic group.

CONCLUSIONS

Hand instrumentation has resulted in more surface roughness as compared to ultrasonic instruments.

A split-mouth randomized controlled trial to compare the rate of canine retraction after a soft tissue procedure compared against a corticotomy procedure for accelerated tooth movement

Background and Aim

Various methods to accelerate the orthodontic tooth movement have been used, among which corticotomy is considered to be the most common one. The suggested reasoning for such acceleration was the regional acceleratory phenomenon (RAP). Since the RAP is a property of both the hard and soft tissues, we designed a soft tissue flap procedure to compare the effects with the conventional corticotomy procedure. A split-mouth study was conducted where the two procedures were assessed in a single participant.

Patients and Methods

The total sample size was calculated to be 40 with 20 participants in each group. The rate of tooth movement was the primary outcome measure, and the secondary outcomes were dentoalveolar changes, which were studied in both the conventional corticotomy and the flap-only procedure based on a cone-beam computed tomography (CBCT) wherein the alveolar bone density (BD) around canines, tipping, and rotational changes in canines, premolars, and molars were assessed.

Results

Corticotomy resulted in greater canine angulation, lesser canine rotation and premolar rotation, and greater molar rotation compared with flap elevation, but these differences were statistically insignificant.

Conclusion

Though the corticotomy resulted in higher BD, the differences were statistically insignificant. There was no significant difference in the rate of space closure assessed by the two techniques compared.

Assessment of Serum Electrolytes and Glycated Hemoglobin Level in Non-diabetic Iron-Deficient Anaemic Patients

INTRODUCTION

The WHO has recognised iron deficiency anaemia (IDA) as the most common nutritional deficiency in the world, with 30% of the population being affected by this condition. The patient's glycemic status during the past three months is shown by the glycated haemoglobin A1C (HbA1c) test. According to several studies, iron deficiency can increase HbA1C levels without affecting blood sugar levels. HbA1C levels of ≥ 6.5% have been approved by the American Diabetes Association (ADA) as a diagnostic indicator for diabetes mellitus (DM). An imbalance in serum electrolyte levels and anaemia have been linked by several studies.  Aim: To analyze the effect of iron deficiency anaemia on HbA1c levels and serum electrolytes in an adult non-diabetic population.

METHODS

This was a descriptive cross-sectional study conducted in Shri BM Patil Medical College, Hospital and Research Centre, Vijayapura, Karnataka, India from January 2021 to June 2022. A total of 65 moderate to severe normoglycemic iron deficiency anemia patients between 18 to 75 years were enrolled in the study after fulfilling inclusion and exclusion criteria. A detailed history, clinical and biochemical examination was performed including HbA1c levels. The results were pooled and statistical analyses were performed using Statistical Package for Social Sciences (SPSS) version 20 (IBM Corp., Armonk, NY, USA).

RESULTS

We found elevated HbA1c levels (5.67±1.1%) in non-diabetic iron-deficient anaemia individuals, and elevation was more in women of reproductive age group (30.8%). There was a statistically significant Spearman negative correlation between hemoglobin and HbA1C levels. Also, 16 patients had hyponatremia with a mean haemoglobin (Hb) of 4.8 g/dL and one patient had hyperkalemia with a mean Hb of 3.2 g/dL which was statistically non-significant.

CONCLUSION

In this study haemoglobin and HbA1c had a statistically significant positive correlation with serum sodium and a negative correlation with serum potassium in moderate to severely iron-deficient anaemic patients, especially females of the reproductive age group.

Antimicrobial Efficacy of Blended Essential Oil and Chlorhexidine against Periodontal Pathogen (P.gingivalis)-An In Vitro Study

Background

Essential oils (EOs) have a considerable amount of therapeutic and preventive effect in treating dental diseases due to their wider potential as antibacterial and anti-inflammatory agents. EOs like virgin coconut oil, eucalyptus oil, peppermint oil thyme oil, and clove oil, when used in combination, may further have enhanced antimicrobial effects. However, limited information exists on the synergistic effect of these oils when used in combination, especially on the primary periodontal pathogen Porphyromonas gingivalis.

Aim

The current study aims to compare the antimicrobial efficacy of commercially available EO on the periodontal pathogen, P. gingivalis, in comparison to chlorhexidine (CHX).

Materials and Methods

Antimicrobial efficacy of EO and CHX was assessed at various concentrations against the periodontal pathogen P. gingivalis, by evaluating the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).

Results

P. gingivalis was seen to be sensitive at a MIC of 100 μg/ml and 50 μg/ml concentration of the EO, which is regarded as the MIC of EO against P. gingivalis and CHX effectively inhibited microbial growth at 0.4 μg/ml.

Conclusion

A combination of EOs possesses a potent antibacterial activity against P. gingivalis, and the antibacterial efficacy increases with increasing concentration of EOs.

Investigation of the Coupled Effect of IFT Reduction and Wettability Alteration for Oil Recovery: New Insights

Interfacial tension (IFT) reduction and wettability alteration (WA) are both important enhanced oil recovery (EOR) mechanisms. In oil-wet formations, IFT reduction reduces the magnitude of negative capillary pressure, releasing trapped oil. WA changes the negative capillary pressure to positive conditions, helping the entrance of the aqueous phase, and the displacement of the oil phase. In most cases, IFT reduction and WA happen at the same time. However, studies regarding the coupled effect provided different, sometimes conflicting observations. It requires further study and better understanding. In our study, oil-aged Indiana limestone samples were chosen to represent oil-wet carbonate rocks. Static contact angle and spinning drop method were adopted for wettability assessment and IFT measurement, respectively. Spontaneous imbibition was adopted to reflect on the oil recovery mechanisms in different cases. The impact of IFT reduction, WA, and permeability on the coupled effect was discussed by choosing four pairs of comparison tests. Results showed that when the coupled effect took place, both a higher IFT value and a stronger WA performance resulted in faster and higher oil recoveries. The importance of IFT reduction was enhanced in the higher-permeability condition, while the importance of WA was enhanced in the lower-permeability condition.

Papillary Thyroid Carcinoma Arising from Thyroglossal Cyst-an Institutional Experience over a Decade

Papillary carcinoma constitutes 80% of thyroglossal duct cyst carcinoma (TGCC). The mainstay of treatment for TGCC is Sistrunk procedure. Due to lack of clear-cut guidelines in managing TGCC, the role of total thyroidectomy, neck dissection and adjuvant radioiodine therapy is still debatable. This was a retrospective study which included cases of TGCC treated in our institution over a period of 11 years. The aim of study was to assess the need for total thyroidectomy in management of TGCC. Patients were divided into two groups based on the surgical treatment they underwent and the treatment outcomes were compared. The histology was papillary carcinoma in all cases of TGCC. Overall, 43.3% of TGCCs had a focus of papillary carcinoma in total thyroidectomy specimen. Lymph node metastasis was noted only in 10% of TGCC and not identified in isolated papillary carcinoma confined to thyroglossal cyst. 7-year overall survival (OS) for TGCC was 83.1%. Prognostic factors like extracapsular extension or lymph node metastasis did not affect OS. Addition of total thyroidectomy and neck dissection to Sistrunk procedure did not offer any survival advantage. In a case of TGCC, FNAC should be done from any clinically suspicious thyroid nodules or lymph nodes. TGCC has a good prognosis following treatment and none of the cases in our series has disease recurrence during follow-up. Sistrunk procedure was an adequate procedure for treatment of TGCC with clinically and radiologically normal thyroid gland.

Paternal stress alters synaptic density and expression of GAP-43, GRIN1, M1 and SYP genes in the hippocampus and cortex of offspring of stress-induced male rats

Adverse experiences during pregnancy have a negative impact on the neuronal structure and behavior of offspring, but the effects of a father's life events on the outcome of progeny are scarce. The present study is intended to investigate whether paternal stress affects the offspring brain structure, especially those regions concerned with learning and formation of memory, namely the hippocampus (HC) and prefrontal cortex (PFC), and also the expression of certain genes linked to learning and memory in the offspring. Induced stress to male rats by five stressors, one per day followed by allowing them to mate with the normal, unstressed female. Synaptophysin immunoreactivity was assessed in the tissue sections of the HC and PFC as well as expression of genes concerned with learning and memory was evaluated by RT-PCR in the progeny of stress-received males. The progeny of stressed rats had reduced antisynaptophysin immunoreactivity in the HC and PFC. The synaptic density in HC was less in the A-S (Offspring of male rats who received stress during adulthood) and PA-S (offspring of male rats who received stress during both adolescence and adulthood) than in P-S (offspring of male rats who received stress during adolescence) and C-C (offspring of control) groups. Similar results were observed even in the PFC. The results of post hoc tests proved that the HC and PFC of the progeny of stress-exposed rats exhibited considerably less synaptic density than control (P<0.05), and the levels of expression of GAP-43, GRIN1, M1, and SYP genes in HC and PFC were down-regulated. This study concludes that paternal adverse experiences can affect the offspring's synaptic plasticity and also the genes, which can regulate learning and formation of memory.

Evaluation of cardiovascular risk scores after implementation of digital therapeutic intervention in patients with uncontrolled primary hypertension

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Terrals Technologies Private Limited

Background

Cardiovascular risk scores serve as a useful tool to reinforce the importance of lifestyle modifications and treatment compliance. Yet, there remains a gap between advice by the physician and its implementation by the patient. Digital therapeutics (DTx) as a technology based approach can help bridge this gap. In this context, knowing the quantum of change in disease outcomes and long term cardiovascular risk after DTx implementation can be helpful in persuading the patients for lifestyle interventions.

Purpose

To evaluate the change in cardiovascular risk scores in hypertensive patients after a digital therapeutic intervention.

Method

We conducted a prospective, single arm, 12-week intervention trial at two primary care sites in India. A total of 125 subjects within the age group of 30-65 years with primary hypertension (≥ 140/90 mmHg) were enrolled. They were provided DTx intervention which consisted of modification in diet, physical activities, self-monitoring and health education superimposed on behavior science theories. Atherosclerotic Cardiovascular Disease (ASCVD) risk scores from Pooled Cohort Equation were calculated for all subjects before & after the DTx intervention and the change in score was assessed.

Results

We received the data of 116 patients having a mean age of 47.66 ± 9.47 years and mean BMI of 27.20 ± 4.77 Kg/m². After DTx intervention, the change in mean systolic blood pressure, among other ASCVD equation parameters, was -26.38 mmHg (154.77 vs 128.39 mmHg, P&lt;0.001). The corresponding post-intervention 10-year mean ASCVD risk score for the sample population decreased by 4.74% (11.86% vs 7.12%, P&lt;0.001). The 10-year mean relative risk of ASCVD decreased by 39.95 %. Similarly ASCVD lifetime risk score decreased by 3.04% (49.54% vs 46.50%, P&lt;0.001), amounting to mean relative risk reduction of 6%. Female subjects (n=60) showed higher 10-year mean ASCVD risk reduction of 5.70% (11.70% vs 6.00%, P&lt;0.001), compared to male subjects (n=56) who showed 10-year mean ASCVD risk reduction of 3.76% (12.06% vs 8.30%, P&lt;0.001). This amounted to a relative risk reduction of 48.69% and 30.71% for female & male subjects, respectively. Patients with stage 1 hypertension (n=82) showed a reduction in 10-year mean ASCVD risk of 2.86% (9.90% vs 7.04%, P&lt;0.001). Patients with stage 2 (n=30) & stage 3 hypertension (n=4) achieved higher 10-year mean ASCVD risk reduction of 8.67% (16.07% vs 7.40%, P&lt;0.001) & 13.6% (20.88% vs 7.20%, P=.006).

Conclusion

Digital therapeutics enabled intervention has caused a significant decrease in 10-year & lifetime ASCVD risks which can eventually lead to a decrease in cardiovascular complications, morbidity and mortality. Therefore, such intervention programs should be further explored and studied.

Prospective evaluation of digital therapeutic intervention on blood pressure control in Indian patients with uncontrolled primary hypertension

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Terrals Technologies Private Limited

Background

Digital therapeutics (DTx) has emerged as a new approach in recent years making use of connected devices, smartphone software and electronic communication tools to help manage chronic cardiovascular diseases such as hypertension. Considering its nascent stage, many questions still remain with respect to its applicability, effectiveness and limitations.

Purpose

Assess the effectiveness of digital therapeutic intervention in controlling blood pressure in Indian patients with primary hypertension

Methods

We conducted a prospective, 12 week, single arm, interventional study, including 125 subjects at multiple sites in India. Subjects with uncontrolled primary hypertension (≥140 mmHg systolic and/or ≥90 mmHg diastolic) in the age group of 30-65 years who were under routine antihypertensive treatment were enrolled. They were provided supplementary DTx intervention comprising of smartphone application based personalized management of diet, exercise, self monitoring and health education by nutritionists and health coaches. Efficacy endpoints such as blood pressure (BP), body mass index (BMI), lipids, etc. were measured before and after the intervention.

Results

A total of 122 subjects who completed the trial had mean age of 47.44 ± 9.43 years, comprising 58 (48%) male and 64 (52%) female patients and mean BMI of 27.21 ±4.7 kg/m². Post-intervention change in mean systolic BP (SBP) was -25.61 mmHg (95% CI 22.55 - 28.66, 154.98 mmHg vs 129.37 mmHg, P&lt;.001). The post-intervention change in mean diastolic BP (DBP) was -18.62 mmHg (95% CI 16.29 - 20.96, 100.04 mmHg vs 81.42 mmHg, P&lt;.001). Patients with stage 1 hypertension (69.6%) achieved mean systolic reduction of 20.87 ± 13.9 mmHg, (148.54 mmHg vs 127.67 mmHg, P&lt;.001). The patients with stage 2 (27.04%) and stage 3 (3.27%) hypertension achieved a higher mean SBP reduction of 34.67 ± 15.19 mmHg (167.24 mmHg vs 132.58 mmHg, P&lt;.001) and 51.5 ± 40.45 mmHg (190.75 mmHg vs 139.25 mmHg, P=.084), respectively. Male and female patients showed almost similar reduction in systolic BP of 25.47 ± 14.72 and 25.73 ± 19.39 mmHg, respectively. Also, the subjects with other chronic comorbidities (23.9%) achieved a mean systolic BP reduction of 29.51 ± 15.25 mmHg.

A total of 79.51% (n=97) patients achieved the SBP &lt;140 mmHg, while 59.84% (n=73) patients achieved SBP &lt;130 mmHg. Combining both the systolic and diastolic targets together, 65.57% (n=80) patients achieved the target of &lt;140/90 mmHg, while ESC/ESH 2018 recommended BP target of &lt;130/80 mmHg was achieved by 31.15% (n=38) patients.

Conclusion

The implementation of Digital therapeutic application integrated with primary healthcare resulted in significant reduction in blood pressure in participants with uncontrolled hypertension. Greater improvement was observed in participants with higher baseline blood pressure.

Primary Investigation of Barite-Weighted Water-Based Drilling Fluid Properties

Drilling fluid is a critical component in drilling operation due to its various functions. It consists of many elements, and one of the main components is the weighting material which controls the mud density. The weighting material type and concentration have a significant impact on the drilling fluid properties. A common weighting material used in the oil and gas industry is barite. In this work, the impact of barite concentration on water-based drilling fluid was evaluated. The investigated drilling fluid properties are density, pH value, filtration behavior, and rheological parameters. An intense investigation was carried out to evaluate the impact of barite concentration on the filtration and filter cake sealing properties. The density and pH values were measured at room temperature, filtration test was performed at room temperature, and differential pressure was equal to 100 psi. The rheological parameters were determined after hot rolling for 16 h at a temperature of 250 °F. The results showed that both the density and pH value increased linearly with barite dosage. The filtration volume, filter cake thickness, and permeability increased with the incremental increase in barite dosage, and the exponential relationship was the best in describing the relation with barite concentration. However, the filter cake porosity had an inverse proportional relation with barite dosage. In the case of rheological properties, all the investigated properties including the plastic viscosity, yield point, ratio of yield point to plastic viscosity, and gel strength at two different times (i.e., 10 s and 10 min) increased in general as the barite concentration increased.

Correlation of TIRADS and Bethesda Scoring Systems with Final Histopathology of Thyroid Nodules - An Institutional Experience

Fine needle aspiration cytology (FNAC) reduces the number of unnecessary thyroid surgeries for patients with benign nodules and appropriately triages patients with thyroid cancer to appropriate treatment. This was a observational study done on cases presenting with clinical suspicion of thyroid malignancy which underwent ultrasonography followed by FNAC of thyroid nodule. Ultrasonographic characterization of nodules was based on Thyroid Imaging Reporting and Data System (TIRADS) and cytology reporting was based on Bethesda system. All recruited patients underwent thyroidectomy. Pre-operative cytology and ultrasonography features were compared with final histopathology report. In our study, Bethesda system of cytology reporting for thyroid nodules had a better sensitivity, specificity and diagnostic accuracy than TIRADS system of ultrasound reporting. Bethesda system in FNAC had a larger area under the ROC curve (0.91) as compared to ultrasound TIRADS (0.70). Malignancy rate of TIRADS 5 nodules was 97.1% with significant p value (0.022). 100% of Bethesda VI lesions were malignant according to final histopathology report. Ultrasound TIRADS could pre-operatively predict malignancy in 63.6% of indeterminate thyroid nodules which were malignant according to post-operative histopathology. The overall concordance of ultrasound TIRADS, Bethesda system and histopathology was 69.8%. Higher TIRADS and Bethesda scoring among thyroid nodules was associated with increased risk of malignancy. US TIRADS is a good predictor of malignancy in indeterminate thyroid nodules.

Experimental Study on the Application of Cellulosic Biopolymer for Enhanced Oil Recovery in Carbonate Cores under Harsh Conditions

Polymer flooding is used to improve the viscosity of an injectant, thereby decreasing the mobility ratio and improving oil displacement efficiency in the reservoir. Thanks to their environmentally benign nature, natural polymers are receiving prodigious attention for enhanced oil recovery. Herein, the rheology and oil displacement properties of okra mucilage were investigated for its enhanced oil recovery potential at a high temperature and high pressure (HTHP) in carbonate cores. The cellulosic polysaccharide used in the study is composed of okra mucilage extracted from okra (Abelmoschus esculentus) via a hot water extraction process. The morphological property of okra mucilage was characterized with Fourier transform infrared (FTIR), while the thermal stability was investigated using a thermogravimetric analyzer (TGA). The rheological property of the okra mucilage was investigated for seawater salinity and high-temperature conditions using a TA rheometer. Finally, an oil displacement experiment of the okra mucilage was conducted in a high-temperature, high-pressure core flooding equipment. The TGA analysis of the biopolymer reveals that the polymeric solution was stable over a wide range of temperatures. The FTIR results depict that the mucilage is composed of galactose and rhamnose constituents, which are essentially found in polysaccharides. The polymer exhibited pseudoplastic behavior at varying shear rates. The viscosity of okra mucilage was slightly reduced when aged in seawater salinity and at a high temperature. Nonetheless, the cellulosic polysaccharide exemplified sufficiently good viscosity under high-temperature and high-salinity (HTHS) conditions. Finally, the oil recovery results from the carbonate core plug reveal that the okra mucilage recorded a 12.7% incremental oil recovery over waterflooding. The mechanism of its better displacement efficiency is elucidated

Mucosal Melanomas of the Oral Cavity: A Tertiary Care Centre Experience of Surgically Treated Cases

Mucosal melanoma of oral cavity (MMO) is a relatively rare tumour comprising of 40% of all head and neck mucosal melanomas. This study assessed the treatment outcomes and factors affecting prognosis in oral cavity mucosal melanomas. The clinical case records of 25 cases of oral cavity mucosal melanomas treated in our institution during 2003-2013 were retrospectively reviewed. Various clinicopathological parameters were taken into consideration and statistical analysis done by Kaplan-Meier method and Cox's proportional hazards model. The most common sites of MMO were upper alveolus and hard palate (64%) followed by lower alveolus (28%). 57.1% mucosal melanomas of hard palate and upper alveolus had associated metastatic lymph nodes whereas all cases of MMO of lower alveolus had lymph node metastasis. Disease failure at distant sites was higher than that at primary site or lymph nodes. The most common site of distant metastases was brain. The 5-year OS for treated cases was 23.8% and among subsites, MMO of hard palate and upper alveolus had the highest survival. Metastasis to lymph nodes and bone infiltration by tumour significantly decreased the survival. Recurrence at primary site had the worst prognosis. MMO with lymph nodal involvement and bone erosion had poor prognosis. Due to high chances of lymph node metastases and disease recurrence in lymph nodes following treatment, it is essential to do an elective neck dissection for all cases of MMO. Disease failure at primary site was an independent predictor of outcome in MMO.

Anti-microbial efficacy of root canal preparation in deciduous teeth with manual and rotary files: A randomized clinical trial

BACKGROUND

In a pulpectomy, the eradication of microbes from the primary root canal is accomplished through biomechanical preparation, which could be carried out with either manual or rotary instruments.

AIMS

The objective of this clinical trial was to evaluate the efficiency of manual K-files, H-files, and Kedo-S Square rotary files in reducing microbial flora after canal preparation in primary molars.

MATERIALS AND METHODS

This randomized clinical trial consisted of 45 primary molars requiring pulpectomy. The teeth were randomly allocated to one of the three groups: Group I: Manual K-files, Group II: Manual H-files, and Group III: Kedo-S Square rotary files, based on the type of instrumentation. Pre-and Post-instrumentation sampling was performed using clean absorbent paper points and kept in a clean Eppendorf tube having thioglycolate broth as the transport medium. Culturing was performed on agar media from which both aerobic and anaerobic microbial counts were estimated. Collected data were statistically analyzed using one-way analysis of variance (ANOVA) and Wilcoxon signed-rank test. Following root canal preparation, 87-89% reduction of the aerobic and anaerobic microbial load was noted in group I, whereas it was an 89-92% reduction in group II and a 93-95% reduction in group III.

RESULTS

Biomechanical preparation with Kedo-S Square rotary file showed higher efficacy in microbial reduction compared to manual instrumentation.

CONCLUSION

Manual and rotary files were equally effective in removing root canal microbes. Biomechanical preparation with a KedoS Square rotary file resulted in greater microbial efficacy. Hence In children, effective root canal cleaning in a short period of time is a major consideration.

Rheological Study of Seawater-Based Fracturing Fluid Containing Polymer, Crosslinker, and Chelating Agent

Freshwater is usually used in hydraulic fracturing as it is less damaging to the formation and is compatible with the chemical additives. In recent years, seawater has been the subject of extensive research to reduce freshwater consumption. The study aims to optimize the rheology of seawater-based fracturing fluid with chemical additives that reduce the formation damage. The studied formulation consists of a polymer, a crosslinker, and a chelating agent to reduce seawater hardness. We used a standard industry rheometer to perform the rheology tests. By comparing five distinct grades [hydroxypropyl guar (HPG) and carboxymethyl hydroxypropyl guar (CMHPG)], we selected the guar derivative with the best rheological performance in seawater. Five different polymers (0.6 wt %) were hydrated with seawater and freshwater to select the suitable one. Then, the best performing polymer was chosen to be tested with (1.6, 4, and 8 wt %) N, N-dicarboxymethyl glutamic acid GLDA chelating agent and 1 wt % zirconium crosslinker. In the first part, the testing parameters were 120 °C temperature, 500 psi pressure, and 100 1/s shear rate. Then, the same formulations were tested at a ramped temperature between 25 and 120 °C. We observed that higher and more stable viscosity levels can be achieved by adding the GLDA after polymer hydration. In seawater, an instantaneous crosslinking occurs once the crosslinker is added even at room temperature, while in freshwater, the crosslinker is activated by ramping the temperature. We noted that, in the presence of a crosslinker, small changes in the chelating agent concentration have a considerable impact on the fluid rheology, as demonstrated in ramped temperature results. It is observed that the viscosities are higher and more persistent at lower concentrations of GLDA than at higher concentrations. The study shows the rheological response when different chemical additives are mixed in saline water for hydraulic fracturing applications.

Effect of Sulfate-Based Scales on Calcite Mineral Surface Chemistry: Insights from Zeta-Potential Experiments and Their Implications on Wettability

Scale formation and deposition in the subsurface and surface facilities have been recognized as a major cause of flow assurance issues in the oil and gas industry. Sulfate-based scales such as sulfates of calcium (anhydrite and gypsum) and barium (barite) are some of the commonly encountered scales during hydrocarbon production operations. Oilfield scales are a well-known flow assurance problem, which occurs mainly due to the mixing of incompatible brines. Researchers have largely focused on the rocks' petrophysical property modifications (permeability and porosity damage) caused by scale precipitation and deposition. Little or no attention has been paid to their influence on the surface charge and wettability of calcite minerals. Thus, this study investigates the effect of anhydrite and barite scales' presence on the calcite mineral surface charge and their propensity to alter the wetting state of calcite minerals. This was achieved vis-à-vis zeta-potential (ζ-potential) measurement. Furthermore, two modes of the scale control (slug and continuous injections) using ethylenediaminetetraacetic acid (EDTA) were examined to determine the optimal control strategy as well as the optimal inhibitor dosage. Results showed that the presence of anhydrite and barite scales in a calcite reservoir affects the colloidal stability of the system, thus posing a threat of precipitation, which would result in permeability and porosity damage. Also, the calcite mineral surface charge is affected by the presence of calcium and barium sulfate scales; however, the magnitude of change in the surface charge via ζ-potential measurement is insignificant to cause wettability alteration by the mineral scales. Slug and continuous injections of EDTA were implemented, with the optimal scale control strategy being the continuous injection of EDTA solutions. The optimal dosage of EDTA for anhydrite scale control is 5 and 1 wt % for the formation water and seawater environments, respectively. In the case of barite, in both environments, an EDTA dosage of 1 wt % suffices. Findings from this study not only further the understanding of the scale effects on calcite mineral systems but also provide critical insights into the potential of scale formation and their mechanisms of interactions for better injection planning and the development of a scale control strategy.

Iron Sulfide Scale Inhibition in Carbonate Reservoirs

Hydrocarbon production operations include water injection, varying stimulation approaches, and enhanced oil recovery techniques. These treatments often affect reservoir formation, production, and injection facilities. Such sorts of well operations cause the formation of organic and inorganic scales in the near-wellbore region and various production and injection structures. Downhole squeeze treatment is commonly used as a control measure to prevent scale precipitation. A scale inhibitor solution is introduced into a formation by applying a squeeze treatment. The method allows scale inhibitors to adsorb on the internal rock surface to avoid settling down the scale precipitates. Thus, the study of adsorption of different types of inhibitors to prevent scale formation on the reservoir rock through the execution of downhole squeeze treatment is becoming necessary. This study incorporated different experimental techniques, including dynamic adsorption experiments of chelating agents employing a coreflooding setup, inductively coupled plasma-optical emission spectrometry (ICP-OES) to inhibit the formation of iron-containing scales in limestone rocks, and ζ-potential measurements targeting determination of iron precipitation in varying pH environments on calcite minerals. The influence of the inhibitor soaking time and salt existence in the system on chelating agent adsorption was also evaluated in the coreflooding experiments. The findings based on the coreflooding tests reveal that the concentration of chelating agents plays a significant role in their adsorption on carbonate rocks. The treatments with 20 wt % ethylenediaminetetraacetic acid (EDTA) and 20 wt % diethylenetriaminepentaacetic acid produced the highest adsorption capacity in limestone rock samples by inhibiting 84 and 85% of iron(III) ions, respectively. Moreover, the presence of the salts (CaCl₂ and MgCl₂) considerably decreased the adsorption of 10 wt % EDTA to 56% (CaCl₂) and 52% (MgCl₂) and caused nearly 20% more permeability reduction, while more inhibitor soaking time resulted in comparably higher adsorption and lesser permeability diminution. The results of ζ-potential measurements showed that the pH environment controls iron(II) and (III) precipitation, and iron(III) starts to deposit from a low pH region, whereas iron(II) precipitates in increased pH environments in calcite minerals.

Hyperparameter Tuning of Artificial Neural Networks for Well Production Estimation Considering the Uncertainty in Initialized Parameters

A well production rate is an essential parameter in oil and gas field development. Traditional models have limitations for the well production rate estimation, e.g., numerical simulations are computation-expensive, and empirical models are based on oversimplified assumptions. An artificial neural network (ANN) is an artificial intelligence method commonly used in regression problems. This work aims to apply an ANN model to estimate the oil production rate (OPR), water oil ratio (WOR), and gas oil ratio (GOR). Specifically, data analysis was first performed to select the appropriate well operation parameters for OPR, WOR, and GOR. Different ANN hyperparameters (network, training function, and transfer function) were then evaluated to determine the optimal ANN setting. Transfer function groups were further analyzed to determine the best combination of transfer functions in the hidden layers. In addition, this study adopted the relative root mean square error with the statistical parameters from a stochastic point of view to select the optimal transfer functions. The optimal ANN model's average relative root mean square error reached 6.8% for OPR, 18.0% for WOR, and 1.98% for GOR, which indicated the effectiveness of the optimized ANN model for well production estimation. Furthermore, comparison with the empirical model and the inputs effect through a Monte Carlo simulation illustrated the strength and limitation of the ANN model.

Minimizing the Barite Scale in Carbonate Formations during the Filter Cake Removal Process

The barite scale is one of the most common scales in the oil and gas industry. It can form in the reservoir or precipitate in different production equipment. The formation of such a scale will significantly minimize the capillary diameter of the flow channels and consequently shrink the well productivity. On the other hand, the production of movable barite particles causes severe erosion for the installed equipment. There are several sources of the barite scale such as mixing of incompatible brines and solid invasion of the barite weighted during drilling. In addition, the barite scale could be produced during the interaction of the chelating agent solutions with the reservoir formation during the filter cake removal process (secondary damage). The main focus of this study is to prevent the barite scale inside the carbonate formations during filter cake removal. The capability of a solution consisting of both diethylenetriamine pentaacetic acid (DTPA) and ethylenediamine tetraacetic acid (EDTA) as a novel solution to prevent barite scale formation in carbonate formations after the removal of the barite filter cake was evaluated. A series of laboratory experiments were accomplished to characterize the barite scale and evaluate the performance of the proposed solution. In particular, particle size distribution, scanning electron microscopy, X-ray diffraction, core flooding, NMR spectroscopy, solubility test, and inductively coupled plasma (ICP) spectroscopy tests were conducted for this aim. The experiments were performed using carbonate core samples. The results showed that the proposed solution was able to load 35 000 ppm barium in the presence of calcite ions. The addition of EDTA tended to inhibit the barite deposition and improve the rate of the calcite reaction. NMR results showed that a mixture of DTPA and EDTA (20%) can stimulate the macropores, resulting in an increase in the return permeability by 1.4-1.8 times of the initial value, while the precipitation that occurred in the micropores could be ignored with respect to the overall porosity improvements.

Evaluation of the Dynamic Interfacial Tension between Viscoelastic Surfactant Solutions and Oil Using Porous Micromodels

Interfacial tension (IFT) is a crucial parameter in many natural and industrial processes, such as enhanced oil recovery and subsurface energy storage. IFT determines how easy the fluids can pass through pore throats and hence will decide how much residual fluids will be left behind. Here, we use a porous glass micromodel to investigate the dynamic IFT between oil and Armovis viscoelastic surfactant (VES) solution based on the concept of drop deformation while passing through a pore throat. Three different concentrations of VES, that is, 0.5, 0.75, and 1.25% vol% prepared using 57 K ppm synthetic seawater, were used in this study. The rheology obtained using a rheometer at ambient temperature showed zero shear viscosity of 325, 1101, and 1953 cP for 0.5%, 0.75%, and 1.25% VES, respectively, with a power-law region between 2 and 50 1/s. The dynamic IFT increases with the shear rate and then reaches a plateau. The results of IFT were compared with those obtained from the spinning drop method, which shows 97% accuracy for 1.25% VES, whereas the accuracy decreased to 65% for 0.75 VES and 51% for 0.5% VES. The findings indicate that we can reliably estimate the IFT of VES at higher concentrations directly during multiphase flow in porous micromodels without the need to perform separate experiments and wait for a long time to reach equilibrium.