Accuracy comparison of single- and double-sleeve endodontic guides for fiber post removal.

BACKGROUND: This study aimed to assess the accuracy of two different endodontic guides for fiber post removal. METHODS: In this in vitro study, 54 maxillary canine fiber posts were mounted on 36 maxillary stone casts; 18 teeth were mounted unilaterally, and 36 teeth were mounted bilaterally. Static endodontic guides were fabricated according to baseline cone-beam computed tomography (CBCT) and intraoral optical scans using Blue Sky software. In the single-sleeve endodontic guides group (SSG), two anterior and two posterior teeth were included in a 5-unit guide. In the double-sleeve endodontic guides group (DSG) group, the guide was passed through the midline to include both canine teeth and extended by 2 teeth posterior to the canine teeth bilaterally (a 10-unit guide). After drilling, postoperative CBCT scans were taken and superimposed on the virtually designed path, and the maximum coronal deviation (MCD) at the marginal entry point of the tooth, maximum apical deviation (MAD) at 10 mm apical to the tooth margin, and maximum angular deflection (MAnD) of the drill were calculated. RESULTS: The mean MCD, MAD, and MAnD were 0.34 mm, 0.6 mm, and 2.32 degrees, respectively, in the SSG and 0.31 mm, 0.7 mm, and 2.37 degrees, respectively, in the DSG. The two groups were not significantly different from each other in terms of MCD (P = 0.573), MAD (P = 0.290), or MAnD (P = 0.896). CONCLUSIONS: The accuracies of the two techniques, the extended double sleeve guide and the single sleeve guide, were comparable and thus DSG may be used for removal of fiber posts in adjacent or distant teeth.

Application of an Endodontic Static Guide in Fiber Post Removal from a Compromised Tooth.

Removing a fiber post from a root canal that requires endodontic retreatment is often very challenging. Conventional freehand techniques for removing fiber posts are time-consuming, sometimes result in iatrogenic errors, and heavily rely on the practitioner's experience. The endodontic static guide can be an alternative method. While the use of an endodontic 3D-printed static guide for fiber post removal has been reported as highly successful, it can also cause complications. Skipping any critical steps during the guide construction or its clinical application can lead to errors. This case report presents the saving of a compromised tooth with a fractured fiber post and a periapical lesion around the apex through the use of an endodontic static guide for fiber post removal. This study describes possible sources of error that may happen during construction and clinical use of the guide.

Applying artificial intelligence to detect and analyse oral and maxillofacial bone loss-A scoping review.

Radiographic evaluation of bone changes is one of the main tools in the diagnosis of many oral and maxillofacial diseases. However, this approach to assessment has limitations in accuracy, inconsistency and comparatively low diagnostic efficiency. Recently, artificial intelligence (AI)-based algorithms like deep learning networks have been introduced as a solution to overcome these challenges. Based on recent studies, AI can improve the detection accuracy of an expert clinician for periapical pathology, periodontal diseases and their prognostication, as well as peri-implant bone loss. Also, AI has been successfully used to detect and diagnose oral and maxillofacial lesions with a high predictive value. This study aims to review the current evidence on artificial intelligence applications in the detection and analysis of bone loss in the oral and maxillofacial regions.

Incidence, Time Trends and Geographical Distribution of Leukemia and Multiple Myeloma in Golestan Province, Northern Iran, 2004-2017.

BACKGROUND: Leukemia and multiple myeloma (MM) are the most common hematologic malignancies in Iran. This paper describes the geographic and temporal changes in their incidence in Golestan, northern Iran. METHODS: Data on cases of leukemia and MM during 2004-2017 were obtained from the Golestan Population-based Cancer Registry (GPCR). The GPCR is a dynamic database of Golestan residents diagnosed with primary cancers. Age-standardized incidence rates (ASRs) (per 100000) of leukemia and MM were calculated using direct standardization method considering the world standard population. We used Joinpoint regression to assess incidence trends using the average annual percent change (AAPC). RESULTS: In total, 2119 new cases of leukemia and MM were registered by the GPCR during 2004-2017. The ASRs of leukemia were 9.71 and 6.70 in males and females, respectively, while the rates were lower for MM: 2.66 and 1.97 in males and females, respectively. The incidence rates of leukemia suggested an increasing trend in urban population (AAPC=2.73; P value=0.154), while in rural area, the incidence rates were slightly decreasing (AAPC=- 0.73; P value=0.658). There were high incidence areas of leukemia in the central and western regions of Golestan. CONCLUSION: Our results suggested high incidence rates of leukemia and MM in the Golestan province. We also found geographical diversities and increasing trends in the incidence of leukemia in the urban population. Exposure to occupational and environmental carcinogens including pesticides may partly explain high rates and the observed trends. Further investigations should be considered to clarify these points in our population.

Antimicrobial effects of different concentrations of simvastatin versus triple antibiotic paste on Enterococcus faecalis biofilms at different stages of development.

Background. This study assessed the antimicrobial effects of different concentrations of simvastatin versus triple antibiotic paste (TAP) on Enterococcus faecalis biofilms at different stages of development. Methods. In this in vitro study, 70 human single-rooted mature premolars were decoronated, instrumented, and autoclave-sterilized. Next, an E. faecalis suspension was prepared and inoculated into the canals to obtain 4- and 6-week biofilms. After ensuring biofilm formation, the samples in each group were randomly assigned to 5 subgroups (n=12): 1 mg/mL TAP, 10 mg/ mL TAP, 1 mg/mL simvastatin, 10 mg/mL simvastatin, and positive control (phosphate-buffered saline solution). The medicaments were applied in the canals, and the teeth were incubated for one week. Dentin samples were collected by a rotary file, cultured, and the number of E. faecalis colonies was counted. The Kruskal-Wallis, Mann-Whitney U, and Wilcoxon tests were used for data analysis (α=0.05). Results. There were significant differences in colony counts between the two concentrations of TAP and the control group against both 4- and 6-week biofilms (P<0.05). The antibacterial effect of 10 mg/mL TAP and simvastatin was stronger than that of 1 mg/mL concentration against the 4- and 6-week E. faecalis biofilms (P<0.05). Furthermore, 10 mg/mL TAP and simvastatin were more effective against the 4-week biofilms than the 6-week biofilms (P<0.05). Conclusion. According to the present results and since biofilms may remain viable in the root canal system for weeks to months, applying 10 mg/mL TAP and simvastatin might be more effective.

The effects of probiotic supplement on hemoglobin in chronic renal failure patients under hemodialysis: A randomized clinical trial.

BACKGROUND: Chronic inflammation is one of the causes of anemia in chronic renal failure patients under hemodialysis. Probiotics probably establish a balance between pro- and anti-inflammatory cytokines. The study was conducted to determine the effects of probiotic supplementation on hemoglobin (Hb) in hemodialysis patients. MATERIALS AND METHODS: A parallel clinical trial was conducted in which patients were randomly allocated into two groups. The intervention group (n = 18) was given a 500 mg probiotic supplement (a capsule) every day whereas the control group (n = 18) received placebo (a capsule), both for 3 months. Hb levels and C-reactive protein (CRP) levels were measured for three periods. The data were analyzed in SPSS-16 using statistical tests including the t-test and repeated-measures ANOVA. RESULTS: In the probiotic supplementation group, the mean Hb was 9.22 ± 1.04 mg/dl before the intervention and reached 10.85 ± 1.177 mg/dl afterward, while in the placebo group, the mean Hb level was 9.38 ± 0.97 mg/dl before the intervention and reached 10.03 ± 1.97 mg/dl afterward (P > 0.05). During the study, the placebo caused to increase of Hb temporary, but in longer term, the effect of probiotic was more manifested. Hb levels increased in both groups although the change was not statistically significant (P > 0.05). The findings showed no significant differences between the two groups in either the pre- or post-intervention CRP levels (P = 0.239). CONCLUSION: Probiotic supplementation decreased Hb fluctuations in hemodialysis patients but did not result in a significant increase in Hb levels. Similar studies are therefore recommended to be conducted with a prolonged duration of the study or an increased probiotic dose with larger sample size to complete the results of the present study.

Association of serum fetuin-A and biochemical parameters in hemodialysis patients.

Fetuin-A, a hepatic glycoprotein present in the circulation, is a potential inhibitor for systemic calcification. The main aim of this study was to evaluate the association between fetuin-A and other biochemical parameters as facilitator factors for developing atherosclerosis in hemodialysis (HD) patients. This case-control study was conducted on 44 HD patients undergoing treatment in 2012. Parathormone (i-PTH) and fetuin levels were performed by the enzyme-linked immunosorbent assay method, high-sensitivity C-reactive protein (hs-CRP) by chemiluminescence, low-density lipoprotein by direct enzymatic, calcium and albumin by colorimetric and phosphorous by ultraviolet (UV) methods. Chi-square was used for evaluating the association between variables and t-test was used for comparing the mean of the quantitative variables for the two groups. SPSS-16 software was used for data analysis and P-value less than 5% was considered as significant. Mean of serum fetuin level was 23.25 ± 4.90 ng/mL in HD patients and 32.92 ± 5.21 in the control group. Median of hs-CRP was 2.45 mg/dL in the patients and 1.00 mg/dL in the control group and i-PTH was 74.3 pg/mL in the patients and 7.30 pg/mL in the control group. The calcium-phosphorous product was 46.77 ± 14.22 mg/dL in the patient and 31.73 ± 6.48 mg/dL in the control group. A reverse significant association was found between fetuin-A and hs-CRP in this study. In this study, serum fetuin-A level in HD patients was lower than controls. Therefore, a low level of fetuin-A seems to be associated with atherosclerosis, inflammation and malnutrition.

Serum leptin levels and irritable bowel syndrome: a new hypothesis.

GOALS: This study was undertaken to investigate the relationship between serum leptin levels and the development irritable bowel syndrome (IBS). BACKGROUND: Stress has been known as an important causative factor in IBS. Various studies have indicated the relationship between serum leptin levels and stress levels. So searching the relationship between the production and level of this hormone and development of IBS may help to understand the pathophysiology of the disease. STUDY: This was a case-control study. Eighty IBS patient and 80 controls were recruited. All participants were asked to fill in a questionnaire included demographic information and medical history and also a stress questionnaire. Serum leptin level was measured by enzyme-linked immunosorbent assay method. Chi-square, Student t test, Pearson correlation and logistic regression were used for investigating the relationships between variables. RESULTS: Mean serum leptin levels were 7.41 and 19.33 ng/mL in IBS and control groups, respectively (P<0.001). Participants in IBS group had significantly higher stress levels than controls (P<0.001). Multivariate logistic regression analysis showed that adjusted odds ratios (ORs) for serum leptin level (OR: 0.9; 95% confidence interval: 0.85-0.94) and stress level (OR: 1.15; 95% confidence interval: 1.09-1.23) were nearly the same as crude ones. CONCLUSIONS: This study indicated the relationship between leptin and IBS for the first time. Our results show that serum leptin level is significantly lower in IBS group than controls and this relationship is independent of other variables such as stress levels, body mass index, etc. This may help in better understanding of the pathogenesis of IBS and consequently lead to the development of more effective treatments.